David Kipping: Alien Civilizations and Habitable Worlds | Lex Fridman Podcast #355

I think it's actually not that hard to imagine we are the only civilization in the Galaxy right now living yeah that's that's currently extent but there may be very many extinct civilizations if each civilization has a typical lifetime comparable to let's say AI is the demise of our own that's only a few hundred years of technological development or maybe 10,000 years if you get back to the neic re Revolution the dawn of Agriculture you know hardly anything in Cosmic time span um that that's nothing that's the blink of an eye and so it's not surprising

at all that we would happen not to coexist with anyone else but that doesn't mean nobody else was ever here and if other civilizations come to that same conclusion and realization maybe they scour the Galaxy around them they find any evidence for intelligence then they have two options they can either give up on communication and just say well it's never going to happen uh we just may as well just you know worry about what's Happening Here on their own planet or they could attempt communication but communication through time the following is a conversation with David

Kipping an astronomer and astrophysicist at Columbia University director of the cool worlds lab and he's an amazing educator about the most fascinating scientific phenomena in our universe I highly recommend you check out his videos on the Cool World's YouTube channel David quickly became one of my favorite human beings I hope to talk to him uh many more times in the future this is Alex Reedman podcast to support it please check out our sponsors in the description and now dear friends here's David Kipping your research at Colombia is in part focused on what you call cool

worlds or worlds outside our solar system where temperature is sufficiently cool to allow for moons rings and Life to form and for us humans to observe it so can you tell me more about this idea this place of cool world yeah the history of discovering planets outside our solar system was really dominated by these hot planets and that's just because of the fact they're easier to find when the very first methods came online these were primarily the Doppler spectroscopy method looking for wobbling stars um and also the transit method and these two both have a

really strong bias towards finding these hot planets now hot planets are interesting the chemistry in their atmosphere is fascinating it's very alien um an example of one that's particularly close to my heart is tra 2B whose atmosphere is so dark it's less reflective than coal and so they have really bizarre photometric properties yet at the same time they resemble nothing like our own home and so it said there two types of astrophysicists the astrophysicist who care about how the universe works they want to understand the mechanics of the Machinery of this universe why did the

big bang happen why is the universe expanding how are galaxies formed and there's another type of astrophysicist which perhaps um speaks to me a little bit more it Whispers into your ear and that is why are we here are we alone are there others out there and ultimately along this journey the hot plants aren't going to get us there we when we're looking for life in the universe seems to make perfect sense that there should be plets like our own out there maybe even moons like our own planet around gas giants that could be habitable

and so my research has been driven by trying to find these more tulous globes that might resemble our own Planet so they're the ones that lurk more in the shadows in terms of how difficult it is to detect they're much harder they're harder for several reasons the method we primarily use is the transit method so this is really eclipses as the planet passes in front of the star it blocks out some Starlight the problem with that is that not all planets pass in front of their star they have to be aligned correctly from your line

of sight and so the further away the planet is from the Star the cooler is the less likely it is that you're going to get that geometric alignment so whereas a hot Jupiter about 1% of hot Jupiter's will transit in front of their star only about uh 05% maybe even a quarter of a percent of earthlike planets will have the right geometry to Transit and so that makes it much much harder for us what's the connection between temperature of the planet and geometric alignment probability of geometric alignment there's not a direct connection but they're connected

by an intermediate parameter which is their separation from the Star so the planet will be cool if it's further away from the Star which in turn means the probability of getting that alignment correct is going to be less on top of that they also Transit their star less frequently so if you go to the telescope and you want to discover a hot Jupiter you could probably do in a week or so because the orbital periods of order of one 2 3 days so you can actually get the full orbit two or three times over whereas

if you wanted to set an earthlike Planet you have to observe that star for 3 four years and that's actually one of the problems with Kepler Kepler was this very successful mission that NASA launched um over a decade ago now I think and it discovered thousands of planets it's still the dominant source of exoplanets that we know about but unfortunately it didn't last as long as we would have liked it to it died after about 4.35 years I think it was and so for an earthlike Planet that's just enough to catch four transits and four

transits was kind of seen as the minimum but of course the more transits you see the easier it is to detect it cuz you build up signal to noise if you see the same thing tick ti ti tick the more ticks you get the easier is to find it and so it was really a shame that Kepler was just at the limit of where we were expecting it to start to see earthlike planets and in fact it really found zero zero planets that are around stars like the sun are orbit similar to the Earth around

the Sun and could potentially be similar to our own planet in terms of its composition and so it's a great shame but um that's why it gives a strong is more to do in the future just to clarify the transit method mhm is our primary way of detecting these things and what it is is um when the object passes udes the source of light just a tiny bit a few pixels and from that we can infer something about its mass and size and distance and geometry all all of that that's like trying to tell what

uh at a party you can't see anything about a person but you can just see by the way they include others so this is the method but is this a super far away how many pixels of information do we have basically how high resolution is the signal that we um that we can get about these occlusions you're right in your description I I think just to build upon that a little bit more it might be almost like your vision is completely blurry like you have an extreme you know H prescription and so you can't resolve

anything everything's just blurs and but you can tell that something was there because it just got fainter for a short amount of time something someone passed in front of a light and so that light in your eyes would just dim for a short moment now the reason we have that problem with bless or resolution is just because the stars are so far away I mean these are the closest stars are four light years away but most of the Stars kept looked at were thousands of light years away and so you there's absolutely no chance that

the telescope can physically resolve the star or even the separation between the planet and the star is is too small especially for a telescope like Kepler it's only a meter across in principle you can make those detections but you need a different kind of telescope we call that direct Imaging and direct Imaging is a very exciting distinct way of detecting planets but it as you can imagine is going to be far easier to detect planets which are really far away from their star to do that because that's going to make that separation really big and

then you also want the star to be really close to it so the nearest Stars not only that but you would prefer that planet to be really hot because the hotter it is the brighter it is and so that tends to bias direct Imaging towards plants which are in the process of forming so things which have just formed the planet still got all of its primodial heat embedded within it and it's glowing we can see those quite easily but for the planets more like the Earth of course they've cooled down and so we can't see

that the light is pitiful compared to a newly formed planet we would like to get there with direct Imaging that's the dream is to have the pale blue dot an actual photograph of it maybe even just a one pixel photograph of it but for now the entire solar system is one pixel with certainly with Transit method most other telescopes and so all you can do is see where that one pixel which contains potentially dozens of planets and the star maybe even multiple Stars dims for a short amount of time it dims just a little bit

and from that you can infer something yeah I mean it's it's like being a detective in the scene right it's very it's indirect clues of the existence of the planet it's amazing that humans can do that we're just looking out in these immense distances and looking you know if there's alien civilizations out there like let's say one exactly like our own we like would we even be able to see an earth that passes mhm in the way of its sun and slightly dims and that's the only sign we have of that of that alien humanlike

civilization out there is it's just a little bit of a dimming yeah I mean depends on on the type of star we're talking about if it is a star truly like the sun the dip that that causes is 84 parts per million I mean that's just it's like the same as a um as like a firefly flying in front of like a giant flood light at a stadium or something that's the kind of the brightness contrast that you're trying to compare to so it's it's extremely difficult detection and in the very very best cases we

can get down to that but as I said we don't really have any true Earth analoges that have been in the exlan candidate yet unless you relax that definition you say it's not just doesn't have to be a star just like the sun it could be a star that's smaller than the sun it could be these orange dwarfs or even the red dwarf stars and the fact those stars are smaller means that for the same size Planet passing in front of it more light is blocked out and so a very exciting system for example is

trapis one which has seven plets which are smaller than the earth and those are quite easily detectable not with a space-based telescope even from the ground and that's just cuz the star is so much smaller that the relative increase in or decrease in brightness is enhanced significantly cuz that smaller size so trapis 1e it's a planet which is in the right distance for liquid water it has a slightly smaller size on the earth um it's about 90% the size of the Earth about 80% the mass and it's one of the top targets right now for

potentially having life um and yet it raises many questions about um what would that environment be like this is a star which is 1/8 the mass of the sun it's um stars like that take a long time to come off their adolescence when stars first form like the sun it takes them maybe 10 100 million years to sort of settle in to that main sequence lifetime but for stars like these late M dwarfs as we call them they can take up to a billion years or more to calm down and during that period they're producing

huge amounts of x-rays ultraviolet radiation that could potent rip off the entire atmosphere it may desiccate the plants in the system and so even if water arrived by comets or something it may have lost all that water due to this prolonged period of high activity so we have lots of open-ended questions about these M dwarf planets but they are the most accessible and so in the near term if we detect anything in terms of Bio signatures it's going to be for one of these red dwarf stars it's not going to be a true Earth twin

as we would recognize it as having a yellow star well let me ask you I mean there's a million ways to ask this question I'm sure I'll ask it about habitable worlds let's just go to our our own solar system what can we learn about the planets and moons in our solar system that might contain life whether it's Mars or some of the moons of Jupiter and Saturn what kind of characteristics cuz you said it might not need to be earthlike what kind of characteristics might we we' be looking for when we look for life

it's hard to Define even what life is um but we can maybe do a better job in defining the sorts of things that life does and that provides um some aspects to some Avenue for looking for them um in the classically conventionally I think we thought the way to look for life was to look for oxygen oxygen is a byproduct of photosynthesis on this planet um we didn't always have it certainly if you go back to the Aran period um there was you know you have this period called the Great oxidation event where the Earth

floods with oxygen for the first time and starts to saturate the oceans and then into the atmosphere and so that oxygen if we detect it on another planet whether it be Mars Venus or an exoplanet whatever it is um that was long thought to be evidence for something doing photosynthesis because if you took away all the plant life on the earth the oxygen would just hang around here as a highly reactive molecule it would oxidize things and So within about m milon years you would probably lose all the oxygen on planet Earth so that was

a conventionally how we thought we could look for life and then we started to realize that it's not so simple because a there might be other things that life does apart from photosynthesis um certainly the vast majority of the Earth's history had no oxygen and yet there was living things on it so that doesn't seem like a complete test um and secondly could there be other things that produce oxygen besides from Life um a growing concern has been these false positives in by signature work and so one example of that would be photolysis that happens

in the atmosphere when ultraviolet right hits the upper atmosphere it can break up water vapor the hydrogen splits off to the oxygen the hydrogen is a much lighter Atomic species and so it can actually Escape certainly plets like the Earth's gravity that's why we don't have any hydrogen or very little helium and so that leaves you with the oxygen which then oxidizes the surface and so um there could be a residual oxygen signature just due to this fotsis process so we've been trying to generalize and um certainly recent years there's been other suggestions of things

we could look for in the solar system Beyond uh nitrous oxide basically laughing gas is a product of microbes um that's something that we're starting to get more interested in looking for methane gas in combination with other gases can be an important bio signature uh phosphine as well and phosphine is particularly relevant to the solar system because there was a lot of interest for Venus recently um you may have heard that there was a claim of a bio signature in Venus's atmosphere I think it was like two years ago now and the the judge and

jury is still out on that um there was a very provocative claim and signature of a phosphine like spectral absorption um but it could have also have been some of molecule in particular sulfur dioxide which is not a bio signature so this is a detection of a gas in the atmosphere Venus and and uh it might be controversial on several Dimensions so one how to interpret that two is just thr gas and three is this even the right detection is this is there an error in the detection yeah I mean how much do we believe

the detection in the first place if you do believe it does that necessarily mean there's life there and um what gives how can you have life in the Venus's atmosphere in the first place because that's you know been seen as like a hell hole place for imagining life but I guess the the the counter that has been that okay yes the surface is a horrendous place to imagine life thriving um but as you go up in altitude the very dense atmosphere means that there is a cloud layer um where the temperature and the pressure become

actually fairly similar to the surface of the Earth and so maybe there are microbes stirring around in the clouds which are producing phosphine um at the moment this is fascinating it's got a lot of us reinvigorated about the prospects of going back to Venus and doing another Miss Mission there in fact there's now two NASA missions Veritas and da Vinci which are going to be going back in before 2030 or the 2030s um and then we have a European Mission I think that's slated now and even a Chinese Mission might be coming along the way

as well so we might have multiple missions going to Venus which has long been overlooked I mean apart from the Soviets there really has been very little in the way of exploration of Venus as certainly as compared to Mars Mars has enjoyed most of the activity from NASA's Rovers and surveys um and Mars is certainly fascinating there's you know this signature of methane that has been seen there before um again there the discussion is whether that methane is a product of biology which is possible something that happens on the earth or whether it's some geological

process that we are yet to fully understand could be you know for example a reservoir of methane that's trapped under the surface and it's leaking out seasonally so the nice thing about Venus is if there is a giant living civiliz there it'll be airborne so you can just fly through and collect samples yeah with Mars and uh moons of uh Saturn and Jupiter you're going to have to dig dig under to find the civilizations dead or living right and so yeah maybe it's easier than for Venus because certainly you can imagine just a balloon floating

through the atmosphere um that or a drone or something that would have the capability of just scooping up and sampling um to to dig under the surface of Mars is maybe feasible is with you know especially with something like Starship that could launch you know a huge Digger basically to the surface and you could just excavate away at the surface but for something like Europa um we really are still unclear about how thick the ice layer is um how you would melt through that huge thick layer to get to the ocean and then potentially also

discussions about contamination the problem with looking for life in the solar system which is different from looking for life with exoplanets is that you always run the risk of especially if you visit there of introducing the life yourself right it's very difficult to completely exterminate every single microbe and Spore on the surface of your of your Rover or the surface of your Lander and so there's always a risk of introducing something I mean to some extent there is continuous exchange of material between these plets naturally on top of that as well and now we're sort

of accelerating that process to some degree um and so if you dig into europa's surface which probably is completely pristine it's very unlikely there has been much exchange with the outside world for for its subsurface ocean You Are For the First Time potentially introducing bacterial spores into that environment that may compete or may introduce spous signatures for the life you're looking for and so it's it's almost an ethical question as to how to proceed with looking for life on on those subsurface oceans and I I don't think one we've really have a good resolution for

at this point ethical so you mean ethical in terms of concern for the like for preserving life elsewhere like not to murder it as opposed to the scientific one I mean we always worry about a space virus right coming coming here or or you know some kind of external source and we would be the source of that potential contamination or the other direction yeah I mean they that you know the whatever whatever survives in such harsh conditions be pretty good at uh surviving in all conditions it might be a little bit more resilient and robust

so it might actually take a ride on us back home possibly I mean I'm sure I'm sure that some people would be concerned about that I think we would we would hopefully have some containment uh procedures as if if we did sample return or you mean you don't even really need a sample return these days you can pretty much send like a little micro laboratory to the planet to do all the experiments in you know in situ and then just send them back to your planet the data and so I don't think this is necessary

that especially for a case like that where you might have contamination concerns that you have to bring samples back um although probably if you brought back europan Sushi it would probably sell for quite a bit with the billionaires in New York City Sushi yeah um I would love from an engineering perspective just to see all the different candidates and designs for like the scooper for Venus and the scooper for Europa and and Mars I haven't really look deeply into how they actually like the actual engineering of collecting assembles because that's the engineering of that is

probably essential for not either destroying life or or polluting it with our own microbes and so on so that that's like an interesting engineering challenge I usually for Rovers and Stu focus on the on the robot on the sort of the mobility aspect of it on the robotics the perception and the movement and the planning and the control but there's probably the scooper is probably where the action is the microscopic sample collection so basically you have to first clean your vehicle make sure it doesn't have any earthlike things on it and then you have to

put it into some kind of thing that's perfectly sealed from the environment so if we bring it back or we analyze it it's not um it's not going to bring anything else external in yeah I don't know it it's be that would be an interesting engineering design there yeah I mean CES has been uh leaving these little pods on the surface quite recently there's some neat photos you can find online and it's they kind of look like a lightsaber hilts which so um that yeah to me I I think I tweeted something like uh you

know this weapon is your life like don't lose at curiosity because it's just dumping these little vials everywhere and it's yeah it is scooping up these things and the intention is that in the future um there will be a sample return mission that will come and pick these up um but it's I mean the engineering behind those things is so impressive the thing that blows me away the most has been the land land ings um especially I'm training to be a pilot at the moment so that's the sort of you know watching Landings has become

like my pet hobby on YouTube at the moment and how not to do it how to do it with different levels of uh conditions and things but with the you know when when you think about landing on Mars Just the light travel time effect means that there's no possibility of a human controlling that descent and so you have to put all of your faith and your trust in the computer code or the AI or whatever it is that you've put on board that thing to to make the correct descent um and so there's this famous

period called seven minutes of hell where you're basically waiting for that light travel time to come back to know whether your vehicle successfully landed on the surface of not and during that period you know in your mind simultaneously that it is doing these multi-stages of um deploying its parachute deploying the crane activating its Jets to come down and controlling its descent to the surface um and then the crane has to fly away so it doesn't AC hit the Rover and so there's a series of uh multi-stage points where any any of them go wrong you

know the whole mission could could go AR um and so the fact that we are fairly consistently able to build these machines that can do this autonomously is to me one of the most impressive acts of engineering that NASA have achieved yes the unfortunate fact about physics is the takeoff is easier than the landing and you mentioned Starship one of of the incredible engineering Feats that you get to see is the reusable rockets that take off but they land and they land uh using control and they do so perfectly and sometimes when it's synchronous it's

it's just it's beautiful to see and then with Starship you see the the Chopsticks that catch the ship I mean there's just so much incredible engineering but you mentioned uh Starships is somehow helpful here so what's your hope with Starship what kind of science might it enable Poss there's two things I mean it's the launch cost itself which is hopefully going to mean per kilogram is going to dramatically reduce the cost of it the sort of the even if it's a factor of 10 higher than what Elon originally promised this is going to be a

revolution for the cost to launch that means you could do all sorts of things you could launch um large telescopes which could be basically like jwst but you don't even have to fold them up jwst had this whole issue with a design that it's 6 and 1 half meters across and so you have to there's no fuselage which is that large at the time the Aries 4 wasn't large enough for that and so they had to fold it up into this kind of complicated origami and so a large part of the cost was figuring out

how to fold it up testing that it unfolded correctly repeated testing and you know there was something like 130 fail points or something during this unfolding mechanism and so all of us were holding our breath during that process but if you have the ability to Just Launch you know arbitrarily large masses um at least comparatively compared to jbst and very large mirrors into space you can more or less repurpose groundbased mirrors um the hubo Space Telescope mirror and the jbst mirrors are designed to be extremely lightweight and that increased their cost significantly um they have

this kind of honeycomb design on the back to try and minimize the the weight if you don't really care about weight because it's so cheap then you could just literally grab many of the existing groundbased mirrors across tesk across the world four meter 5 meter mirrors and just pretty much attach them to a chassis and have your own space-based telescope um I think the Breakthrough foundation for instance uh is an entity that has been interested in doing this sort of thing um and so that raises the prospects of having not just one wst that just

you know deris is a fantastic resource but it's split between all of us cosmologists star formation uh astronomers those of us studying exop plants those of us wanting to study you know the ultra deep fields and the origin of the first galaxies the expansion R of the universe everyone has to share this resource but we could potentially each have you know one uh jwst each that is uh maybe just studying a handful of the brightest exoplanet stars and measuring their atmospheres this is important because if you we talked about this planet trapis 1e earlier that

planet if Jud sted it and tried to look for Bio signatures by which I mean oxygen um nitrous oxide methane it would take it of order of 200 transits to get even a very marginal what we call 2 a half Sigma detection of those which basically nobody would believe with with that and 100 transits I mean this thing transits once every six days so you talking about sort of four years of staring at the same star with one telescope there'd be some breaks but it'd be hard to schedule much else because you have to continuously

catch each one of these transits to build up your signal to noise and so JC is never going to do that in principle technically J could technically have the capability of just about detecting a bio signature on an earthlike planet around around a nons sunlike star but still impressively we have basically the technology to do that but we simply cannot dedicate all of its time practically to that one resource and so Starship opens up opportunities like that of mass producing these kinds of telescopes which will allow us to survey for life in the universe which

of course is one of the grand goals of astronomy I wonder if you can speak to the the bureaucracy the political battles the scientific battles for for time on the James web telescope is there there must be a fascinating it's process of scheduling that all scientists are trying to collaborate and figure out what the most important problems are and there's an interesting network of interfering scientific experiments probably they have to somehow optimize over it's it's a very difficult process I don't envy the TAC that are going to have to make this decision we call it

the TAC the time allocation committee that that make this decision um and I've served on these before and it's very difficult I mean typically for Hubble we we were seeing at least 10 sometimes 20 times the number of proposals for telescope time versus available telescope time for J there has been one call already that has gone out we called it cycle one and that was over subscribed by I think something like 6:1 7:1 and uh the cycle 2 which has just been announced uh fairly recently and the deadline is actually the end of this month

so my team totally layser focused on running our proposals right now um that is expected to be much more competitive probably more comparable to what Hubble saw and so it's hard more competitive than the cycle one you said already that's already more competive than the first cycle so I said the first cycle of James web was about 6 to1 um and this will probably more like 20 to1 I would expect so these are all proposals by scientists and so on and it's not like you can schedule at any time cuz if you're looking for transit

times yeah you have you have a a Time critical element yes time critical element and they're conflicting in non like non obvious ways because the the the frequency is different the the duration is different there's there's probably computational needs that are different uh the there's the type of sensors the direction pointing all that yeah it it's hard and there were certain programs like doing a deep field study where you just more or less point the telescope and that's pretty open I mean you're just accumulating photons you can just point at that that patch of the

sky um whenever the telescope is not doing anything else and just get to your month let's say a month of integration time is your is your goal over the lifetime jst so that's maybe a little bit easier to schedule it's harder especially for us looking at cool worlds um because as I said earlier these these plants Transit very infrequently MH so we have to wait if you're looking at the Earth transiting the Sun an alien watching us they they would only get one opportunity per year to do that observation the transit lasts for about 12

hours um and so if they don't get that time it's hard you that's it if it conflicted with another proposal that wants to do use the another time critical element it's much easier for plants like uh these hot these hot plants or these close-in plants um because they Transit so frequently there's may be a 100 opportunities and so then the tat can say okay they want 10 transits there's 100 opportunities here it's easier for us to give us time give them time um we're almost in the worst case scenario we're proposing to forx Moes around

two cool planets and so we really only have one bite of the Cherry for each one and so our sales pitch has been that these are extremely precious events and more importantly jdst is the only telescope the only machine Humanity has ever constructed which is capable of finding moons akin to the moons in our solar system kepa can't do it even Hubble can't do it J is the first one and so there is a new window to the universe because we know these moons exist they they're all over the place in the solar system you

have the moon you have IO Kalisto Europa ganime Titan lots of moons of Fairly similar size s of 30% the size of the Earth and this telescope is the first one that can find them um and so we're very excited about the profound implications of ultimately solving this journey we're on in astronomy which is to understand our uniqueness we want to understand how common is the solar system are we the way are we the architecture that frequently emerges naturally or is there something special about what happened here I think this is not the worst case

the best case it's obvious it's super rare so you have to like I would if so I'm I love scheduling from a computer science perspective that's my background so algorithmically to solve a schedule problem I would schedule the rarest things first and obviously this is the the jwst is the first thing that can actually detect a cool world world so this is a big new thing you can show off that new thing happens rarely schedule it first it's perfect you should be in the T this is perfect I will I'll file my application after we're

done with this I I you know this part of me is the OCD part of me is the computational aspect I love scheduling uh Computing device because you have that kind of scheduling on supercomputers on that scheduling problem is fascinating how do you prioritize computation how you prioritize science uh data collection uh sample collection all that kind of stuff stuff it's actually kind of it's kind of fascinating because data in ways you expect and don't expect will unlock a lot of solutions to uh some fascinating Mysteries and so collecting the data and doing so in

a way that maximize the possibility of Discovery is really interesting like from a computational perspective I agree there's there's a real satisfaction in extracting the maximum science per unit time yeah exactly out of your telescope and that's that's the tax job um but the the T are not machines they're not a piece of computer code um they will make their selections based off human judgment and um a lot of the telescope certainly within the field of exoplanets because there's different fields of astronomy but within the field of exoplanets I think a good expectation is that

most of the telescope time that jwc have will go towards atmospheric retrieval which is uh sort of alluded to earlier you know like detecting molecules in the atmospheres not bio signatures CU as I said it's really not designed to do that it's pushing Jus T probably too far to expect to do that but it could detect for example a carbon dioxide Rich atmosphere on trapis one that's not a bi signature but you could prove it's like a Venus in that case or maybe like a Mars in that case like both those have carbon dioxide Rich

atmospheres doesn't prove or disprove the existence of life either way but it is our first characterization of the nature of those atmospheres maybe we can even tell the pressure level and the temperature of those atmospheres so that's very exciting but um there's we we are competing with that and that I I think that science is completely mind-blowing and fantastic we have a completely different objective which is in our case to try and look for the first evidence of these small moons around these planets um potentially even moons which could be habitable of course so I

think it's a very exciting goal but um attack has to make a human judgment essentially about which science are they most excited by which one has the highest promise of return the most highest chance of return and so that's hard because if you look at a planetary atmosphere well you know most of the time the planet has an atmosphere already and so there's almost a guaranteed success that you're going to learn something about the Atmosphere by pointing J at it whereas in our case there's a harder cell we are looking for something that we do

not know for sure exists yet or not and so we are pushing the telescope to do something which is inherently more risky yeah but the existence if shown already gives a deep lesson about what's out there in the universe that means that other stars have similar types of variety as we have in our solar system they have an IO they have a Europa and so on which means like there's a lot of possibility for Icy planets for water for planets that enable planets and moons that I mean that that's super exciting because that that means

everywhere through our galaxy and Beyond there is just innumerable possibility for weird creatures I agree life fors you don't have to convince me I mean NASA NASA has been on this quest for a long time and it's sometimes called eer Earth it's the frequency of Earth like usually they say planets in the universe how common are planets similar to our Earth in terms of um ultimately we'd like to know everything about these plets in terms of the amount of water they have how much atmosphere they have but for now it's kind of focused just on

the size and the distance from the Star essentially how how often do you get similar conditions to that um that was kep's primary Mission and it really just kind of flirted with the answer didn't quite get to a definitive answer but I always say look if we're looking if if that's our primary goal to look for earthlike I would say worlds then moons has to be a part of that because we know that um Earth likee and from the capit DAT to the preliminar is that earthlike planets around sunlike stars is not an inevitable outcome

it seems to be something like a 1 to 10% outcome so it's not particularly inevitable that that happens but we do often see about half of all sunlike stars have either a mini Neptune a Neptune or a Jupiter in habital Zone Of Their Stars that's a very very common occurrence that we see yet we have no idea how often they have moons around them which could also be habitable and so there may very well be if if even one in five of them has an earth like moon or even a Mars like Moon around them

then there would be more habitable real estate in terms of exomoons than exoplanets in the universe you can essentially 2x 3x 5x maybe 10x the number of Hab habitable worlds out there in the universe our current estimate for like the Drake equation absolutely so this this is a one way to increase the confidence and increase the the value of that parameter and just know where to look I mean we we would like to know where should we listen for technos signatures where should we be looking for Bio signatures um and not only that but what

role does the does the moon have in terms of its influence on the planet um we talked about these directly imaged telescopes earlier these missions that want to take a photo to quote car Sean the pale blue dot of our planet but the pale blue dot of an exoplanet and that's the dream to one day capture that but as impressive as the resolution is that we are planning and conspiring to design for the future generation telescopes to achieve that even those telescopes will not have the capability of resolving the Earth and the moon within that

it'll be a pale blue dot pixel but the moon's gray grayness will be intermixed with that pixel and so this is a big problem because one of the ways that we are claiming to look for life in the universe is a chemical disequilibrium so you see two molecules that just shouldn't be there they normally react with each other or even one molecule that's just too reactive to be hang around the Atmosphere by itself so if you had um oxygen and methane hanging out together those would normally react fairly easily and so if you detected those

two molecules in your pale blue dot Spectra you be like okay we we have evidence for life something's metabolizing on this planet um however the challenge here is what if that moon was Titan Titan has a methane Rich atmosphere and what if the pale blue dot was in fact a plant devoid of life but it had oxygen because of water undergoing this photolysis reaction splitting into oxygen hydrogen separately so then you have all of the uh Hallmarks of what we would claim to be life mhm but all along you were tricked it was just a

moon that was deceiving you and so we are never going to we're never going to I would claim really understand the or or complete this quest of looking for Life by a signatures in the universe unless we have a deep knowledge of the prevalence and role that moons have they may even affect the habitability of the planets themselves of course our moon is freakishly large by mass ratio it's the largest moon in the solar system it's a 1% Mass Moon if you look at Jupiter's moons they're like 10^ minus 4 much smaller and so our

own moon seems to stabilize the obliquity of our planet it gives rise to Tides especially early on when the moon was closer those Tides would have covered entire continents and those those Rock pools that would have been scattered across the entire plateau may have been the origin of Life on our planet the moon forming impact may have stripped a significant fractional lithosphere of the earth which without it plate tectonics may not have been possible we would have had a stagnant lid because there was just too much lithosphere stuck on the top of the of the

planet and so there are speculative reasons but intriguing reasons as to why a large Moon may be not just important but Central to the question of having the conditions necessary for life so moons can be habitable in their own right but they can also play significant influence on the habitability of the planets they orbit and further they will surely interfere with our attempts to detect life remotely from AAR so uh taking a tangent upon a tangent uh you've written about uh binary planets what what's and that they're surprisingly common or they might be surprisingly common

what's the difference between a large Moon and binary planets what what are binary planets what uh what's interesting to say here about giant rocks flying to space and orbiting each other the thing that's interesting about binary objects is that they're very common in the universe binary stars are everywhere fact the majority of stars seem to live in binary systems um when we look at the outer edges of the solar system we see binary Kyer Bel objects all the time asteroids Bally bound to one another Pluto Sharon is kind of an example of that it's a

10% Mass ratio system it almost is by many definitions a binary Planet but now it's a dwarf planet so yeah I don't know what you call that now but we we know that these you know the universe likes to make things in pairs yeah um so you're saying our sun is an incel it's it's looking so most things are dating they're in relationships and our ours is alone it it's not a complete free of the universe to be alone but it is um it's more common for sunl stars if you count up all the sunl

stars in the universe about half of the sunlike star systems are in binary or trinary systems and the other half are single but because those binaries are two or three stars then cumulatively maybe like a third of all sunic stars are single I'm trying hard to not anthropomorphize the relationship the star with each other triplet the triplet yeah that's yeah I've met those folks also um so is there something interesting to learn about the habitability the how that affects the probability of habitable worlds when they kind of couple up like that in those different ways

well it depends when we're talking about the stars of the planet certainly if Stars couple up that has a big influence on the habitability um of course this is very famous from Star Wars Tatooine in Star Wars there's a binary star system and you have Luke Skywalker looking at the sunset and seeing two stars come down and uh for years we thought that was purely a product of George Lucas's incredibly creative mind and we didn't think that planets would exist around binary star systems it seems like too tumultuous an environment for a quiescent planetry disc

circumstellar disc to form planets from and yet uh one of the astounding discoveries from Kepler was that these appear to be quite common in fact as far as we can tell uh they're just as common around binary stars as single Stars the only uh caveat to that is that you don't get plants close into binary Stars they have like a clearance region in on the inside where plants maybe they form there but they they don't last they are dynamically unstable in that zone but once you get out to about the distance of the Earth orbits

the Sun or even a little bit closer in you start to find plants emerging and so that's the right distance for liquid water it's the right distance for potentially life on those plants and so there may very well be plenty of habital plants around the binary Stars binary plants is a little bit different um binary plants I don't think we have um any serious connection of plant binarity to habitability certainly when we investigated it that wasn't our drive that this is somehow the solution to life in the universe or anything it was really just a

like all good science questions a curiosity driven question what's the dynamic are they legit orbiting each other as they orbit this uh the star so the formation mechanism proposed here um because it is very difficult to form two Proto plets close to each other like this they were generally merged within the dis and so that's why you normally get single planets but you could have something like Jupiter and Saturn form at separate distances they could dynamically be scattered in towards one another and basically not quite Collide but have a very close on encounter now because

uh tidal forces increase dramatically as the distance decreases between two objects the tides can actually dissipate the kinetic energy and bring them bound into one another so that seemed when we you know when you first hear that you think well that seems fairly contrived that you'd have the conditions just right to get these ties to cause a capture but numerical simulations have shown that about 10% of planet planet encounters are shown to produce something like bino planets which is a startling prediction um and so that seems at odds with naively the exoplanet catalog for which

we know of so far no binary planets and we proposed one of the resolutions to this might be that the bin planets are just incredibly difficult to detect which is also counterintuitive because remember how they form is through this tidal mechanism and so they form extremely close to each other sort of the distance that iio is away from Jupiter just a few planetry radi they're almost touching one another and they're just tily locked facing each other for eternity and so in that configuration as it transits across the star it kind of looks like you can't

really resolve there two planets it just looks like one planet to you that's going across the the star the temporal resolution of the data is rarely good enough to distinguish that and so you'd see one Transit but in fact it's two planets very close together which are transiting at once and so yeah we wrote a paper just recently where we developed um some techniques to try and get around this problem and hopefully provide a tool where we could finally look for these planets the problem of detection of these planets when they're so close that was

our Focus was how do you how do you get around this this merging problem so whether there are or not uh we don't know we we're planning to do a search for them but um it it remains an open question and I think just one of those fun astrophysics Curiosities questions whether binary planets exist in the universe because then you know you have binary Earths you could have binary Neptune all sorts of wild stuff that would you know float to the Sci-Fi imagination I wonder what the physics on a binary Planet feels like it might

be trivial I have to think about that I wonder if there's some interesting Dynamics like it feel multiple or or would gravity feel different at different parts of the the surface of the sphere when there's another large sphere that's I would think that the force would be U fairly similar because the shape of the object would deform to a flat geop potential essentially uniform geop potential but it would lead to a distorted shape for the two objects I think they would become ellipsoids facing one another um so it would be pretty wild when you you

know people like Flat Earth or spherical Earth you fly from space and you see a football shaped Earth it's your own Planet finally there's proof and I wonder how how difficult it would be to travel from one to the other cuz you have to overcome the well no it might be kind of easy yeah I mean they're so close to each other that helps and I think the most critical Factor would be how massive is the planet that's always I mean one of the challenges with escaping planets there was a a fun paper one of

my colleagues wrote that suggested that superar planets may be inescapable mhm if you were a civilization that were born on a superar the surface gravity is so high that the chemical potential energy of hydrogen or or methane whatever fuel you're using simply um is at odds with the with the gravity of the planet itself and so you would uh you know our current Rockets I'm not sure the fraction but maybe like 90% of the rocket is fuel or something by mass these things would have to be um like the size of the the Giza Pyramids

of fuel with just a tiny tip on the top in order just to escape their plan planetry atmosphere and so it has been argued that if you live on a super Earth you may be you may be forced to live there forever there may be no Escape unless you invent a space elevator or something but then how do you even build the infrastructure in space to to do something like that in the absence of a successful rocket program um and so the more and more we we look at our Earth and think about the sorts

of problems we facing the more you see things about the Earth which make it ideally suited and so many regards it it's almost spooky right that we not only live on a planet which has the right conditions for life for intelligent life for sustained fossil fuel industry just happens to be in the ground we have plenty of fossil fuels to to get our Industrial Revolution going um but also the chemical energy contained within those fossil fuels um and hydrogen and other fuels is sufficient that we have the ability to escape our planetary atmosphere and planetary

gravity to have a space program and we also happen to have a Celestial body which is just within reach the moon uh which doesn't also necessarily have to be true where were the moon not there what effect would that have had on our aspirations of a space program in the 1960s would there have ever been a space race to Mars or to Venus it's a much harder certainly for a human program that seems almost impossible with 1960s technology to imagine ever come to FR it's almost as if somebody constructed a set of uh challenging obstacles

before us challenging problems to solve they're challenging but they're doable and there's a sequence of them gravity is very difficult to overcome but we have given the size of Earth it's not so bad that we can still actually construct propulsion systems that can escape it yeah and the same with climate change perhaps I mean climate change is the next major problem facing our civilization but we know it is technically surmountable yeah you know it's it's a it's it's it is does seem sometimes like there has been a series of challenges laid out to um progresses

towards a mature civilization that can one day perhaps expand to the Stars I'm a little more concerned about nuclear weapons uh Ai and uh uh natural or artificial pandemics but yes climate CH mean plenty plenty of plenty of fun Milestones that we need to cross uh and we can argue about the severity of each but uh there is no doubt that we live in a world that has serious challenges that are pushing our intellects and our will to the limit of whether we're really ready to progress to the next stage of our development so thank

you for taking the tangent and there there'll be a million more but can we step back to Kepler 1625b what is it and you you've talked about this kind of Journey this effort to discover uh exom moons so moons out there or small cool objects out there uh where does that effort stand and what do CER 1625b yeah I mean I've been searching for Mex Moons for most of my professional career and I think a lot of my colleagues think I'm kind of crazy to to still be doing it you know after after five years

of not finding anything I think most people would probably try doing something else I even had people say that to me they said um you professors and I remember at a a cocktail party took me to the side an MIT professor and he said um you know you should just look look for hot Jupiters they're everywhere it's really you can write papers they're so easy to and I was like yeah but hard jup is just they're not interesting to me I want to do something that I feel intellectually pushes me to the edge and is

maybe a contribution that not no one else could do but maybe um is not certainly the thing that anybody could do I don't want to just be the first to something for the sake of being first I want to do something that feels like a meaningful intellectual contribution to our society and so you know this exim Moon problem has been haunting me for years to try and solve this now as I said we looked for years and years using Kepler and the closest we ever got was just a hint for this one star Kepler 1625

has a Jupiter like planet in orbit of it and that Jupiter like planet is on a 287 day period so it's it's almost the same distance as the Earth around the Sun but for Jupiter um so that was already unusual I don't think people realize that Jupiter likee planets are quite rare in the universe certainly mini Neptunes and Neptunes are extremely common but Jupiter's only about 10% of sunlike stars have Jupiters around them as far as we can tell when you say Jupiter which aspect of Jupiter in terms of its mass and uh it semi

draxis so anything beyond about half an au so half the distance of the Earth and the Sun and something of order of um a tenth of a Jupiter Mass that's the mass of Saturn up to say 10 Jupiter masses which is basically where you start to get to Brown dwarfs those types of objects appear to be somewhat unusual most most solar systems do not have Jupiter's which is really interesting because Jupiter again like the moon seems to have been a pivotal character in the story of the development of our solar system perhaps especially having a

large influence of the development of um the late heavy bombardment and the rate of asteroid impacts that we receive and things like this anyway to come back to 1625 this this Jupiter like planet um had a hint of of something in the data but what I mean by that is when we looked at the transit we got the familiar decrease in light that we always see when a planet TRS in front of the star but we saw something extra just on the edges we saw some extra dips around the outside it was right at the

hairy edge of detectability we didn't believe it because um I think one of the challenges of looking for something for 10 years is that you become your own greatest skeptic and no matter what you're shown you're always thinking I've been it's like falling in love so many times and it and it not working out right you you convince yourself it's never going to be it's never going to happen not for me you know this just isn't this isn't going to happen and so I saw that and I I didn't really believe it because I didn't

dare let myself believe it but being a good scientist we knew we had an obligation to publish it to talk about the result and to follow it up and to try and resolve what was going on so we asked for Hubble space telescript time which was awarded in that case so we were one of those lucky 20 that got telescope time and we studed it uh for about 40 hours continuously and um the to provide some context the dip that we saw in the cap data corresponded to a neptune-sized moon around a Jupiter sized Planet

which was another reason why I was skeptical that we didn't have that in the solar system that seems so strange and then when we got the Hubble data it seemed to confirm exactly that there was two really striking pieces of evidence in the data that suggested this moon was there another was a fairly clear second dip in light pretty clearly resolved by Hubble it was about a five Sigma detection and on top of that we could see the planet didn't Transit when it should have done it actually transited earlier than we expected it to by

about 20 minutes or so and so that's a Hallmark of a gravitational interaction between the planet and the moon we actually expected that you can also expect that if the moon transits after the planet then the planet should come in earlier than expected because the Barry Center the center of mass lives between the two of them kind of like on a on a balancing arm between them and so we saw that as well so the face signature matched up the mass of the moon was measured to be Neptune mass and the size of the moon

was measured to be Neptune radius and so everything just really lined up and um we spent months and months trying to kill it this is my strategy for anything interesting we just try to throw the kitchen sink at it and say we must be tricked by something and so we tried looking at the you know the centroid motion of the telescope at the um the different wavelength channels that have been observe the pixel level information and no matter what we did we just couldn't get rid of it and so uh we submitted to science and

I think at the time science which is one of the top Journal said to us um would you mind calling your paper discovery of an exomoon and I had to push back and we said no we're not calling it that I don't even despite everything we've done we're not calling it a discovery we're calling it evidence for an exomoon because for me I'd want to see this repeat two times three times four times before I really would bet my house that this is the real door and maybe and I I do worry as I said

that perhaps that's my own skepticism self skepticism going too far but um I think it was the right decision and uh since that paper came out there has been continuous interest in this object um another team independently analyzed that star and recovered actually pretty much exactly the same results as us the same dip the same the same wobble of the planet and a third team looked at it and they actually got something different they saw the dip was diminished compared to what we saw they saw a little hint of a dip but not as pronounced

as what we saw and they saw the wobble as well so there's been a little bit of tension about analyzing the reduction of the Hubble data um and so the only way my mind to resolve this is just to look again uh we actually did propose to Hubble straight after that and we said look if our model is right if the moon is there it came in late last time it transited after the planet because of the orbit we can calculate that it should Transit before the planet next time if it's not there if it

doesn't Transit before and if we even if we see a dip afterwards we know that's not our moon it's obviously some instrumental effect with the data we had a causal prediction as to where the moon should be and so I was really excited about that but we didn't get the telescope time and unfortunately if you go further into the future we no longer have the predictive capability because it's like predicting the weather you might be able to predict the weather next week to some level of accuracy but predicting the weather next year becomes incredibly hard

the uncertainties is just grow and compound as you go forward into the future more and more how are you able to know where where the move would be positioned so you're able to tell the the the orbiting like geometry and and and frequency yeah so from the uh basically from the wobbles of the planet itself that tells us the orbital motion of the moon it's the reflex motion of the Moon the planet isn't it just an estimate to where like I'm concerned about you making a strong prediction here because like if you don't get if

you don't uh get the moon where the moon leads on the next time around if you did get Hubble time couldn't that mean something else if you didn't see that like cuz you said it would be an instrumental I feel I I I feel um the strong urge to disprove your which is a really good imperative it's a good way to do science but like uh this is such a noisy signal right or blurry signal maybe uh low resolution signal maybe that's the yeah I mean it's it's a five Sigma signal so that's that's at

the slightly uncomfortable Edge I mean it's often said that for any detection of a first new phenomena you really want like a 20 25 segment detection then there's just no doubt that what you're seeing is Real This was at that edge I mean I guess it's comparable to the higs boson but the higs boson was slightly different because there was so much theoretical impetus as to expect a signal at that precise location um a Neptune size moon was not predicted by anyone no one there's no papers you can find that expect neptun siiz moons around

Jupiter siiz planet so there's I think we were inherently skeptical about its reality for that reason um but this is science in action and when we we you know we fit the wobbles we fit the dips and we we have this 3G geometric model for the motion of the orbit and projecting that forward we were we found that about 80% of our projections led to the Moon to be before so it's not 100% there is there was maybe 20% of the cases it was over here but to me that was a hard enough uh a

hard enough projection that we felt confident that we could refute the ex which was what I really wanted I wanted to refutable That's the basis of science a falsifiable hypothesis how can you make progress in science if you don't have a false iable testable hypothesis and so that was the the the beauty of this particular case so there's a numerical simulation with the moon uh that fits the data that we observed and then you can now make predictions based on that simulation yeah this is so cool okay it's fun these are like little solar systems

that we can simulate on the computer and imagine their motions um but we are we are pushing things to the very limits of what's possible and that's double-edged sword it's both incredibly exciting intellectually but you're always you're always risking to some degree the pushing too far so I'd like to ask you about the uh the the recent paper you co-authored an exom Moon survey of 70 cool giant exop planets and the new candidate coupler 1708 bi I would say this I'd say there's like three or four candidates at this point of which we have published

two of them and to me are to a quite uh compelling and deserve follow-up observation um and so there to get a confirmed detection at least in our case we would need to see it repeat for sure one of the problems with the some of the other methods that have been proposed is that you don't get that repeatability so for instance an example of a technique that would lack that would be gravitational micr lensing so it is possible with a new telescope coming up in the future um called the Roman Space Telescope which is basically

a repurpose by satellite that's the size of the Hubble mirror going up into space um it will stare millions of stars simultaneously and it will look to see instead of whether any of those stars get dimmer for a short amount of time which will be a Transit it'll look for the opposite it'll look to see if anything get brighter and that brightness increase is caused by another planetry system passing in front and then gravitationally lensing light around it to cause a brightening and so this is a method of discovering entire solar system but only only

for a only for a glimpse you just get a short glimpse of it passing like a you know a ship sailing through the night just that that one photo of it now the problem with that is that um it's very difficult you know the physics of of gravitational lensing not surprisingly quite complicated and so there's many many possible solution so you might have a solution which is this could be a red dwarf star with a Jupiter light planet around it that's one solution but another solution is that it's a free floating Planet a rogue Planet

like Jupiter with an earth like Moon around it and those two solutions are almost indistinguishable now ideally we would be able to repeat the observation we be able to go back and see well if the moon really is there then we could predict its masses predict its motion and expect it to be maybe over here next time or something with microlensing it's a one snapshot event M and so for me it's intriguing as a way of revealing something about the examon population but I always come back to transits because it's the only method we really

have that's absolutely repeatable that will be able to come back and prove everyone prove to everyone that look on the 17th of October the moon will be over here and the moon will look like this and we can actually capture that image and that's what we see with of course many EXO planets so we want to get to that same point of full confidence full confirmation the slam dunk detection of these exomoons but um yeah it's it's been a a hell of a journey uh to to try and push the field into that direction and

um is there some resistance to the Transit method not to the transit me I just say to exomoons so the transit method is by far the most the most popular method for looking for exoplanets but um yeah as I've alluded to exomoons is is kind of a niche topic within the discipline of exoplanets and that's largely because there are people I think are waiting for those slam dunks and it was like the if you go back to the first exoplant discovery that was made in 1995 by Misha mayor and Didia kellos um I I think

it's true at the time that they were seen as Mavericks that the idea of looking for plants around Stars was considered fringe science and you know I'm sure many colleagues told them why don't you do something more safe like study eclipsing Stars two binary star systems we know those exist so why are you wasting your time looking for planets you're going to get this um alien moniker or something and you'll be you'll be seen as a fringe Maverick scientist and so I think it was quite difficult for those early Planet Hunters to get legitimacy and

be taken seriously and so very few people risked their careers to do it except for those that were either emboldened to try or had maybe the career uh maybe like tenure or something so they didn't have to necessarily worry about the implications of failure and so once that happened once they made the first discoveries overnight you know everyone and their dog was getting into exop players and all of a sudden the whole you know the whole astronomy Community shifted and huge numbers of people that were Once Upon a Time studying eclipse in Aries you know

changed to becoming exoplanet scientists and so that was the first wave of exoplanet scientists we're now in a kind of a second wave or even the third wave where people like me to some degree kind of grew up with the idea of exoplanets as being normal you know I was 11 years old I guess when the first ex planet was discovered and so to me it was a fairly uh normal idea to grow up with um and so we've been trained in exoplanets from the very beginning and so that brings different perspective to those who

have maybe transitioned from a different career path um and so I suspect with exomoons and probably technos signatures uh astrobiology many of the topics which are seen at the the fringes of what's possible they will all open up into becoming mainstream one day but every there's a lot of people who are just waiting uh waiting for that that assuredness that there is a secure career re net ahead of them before they commit yeah it it does seem to me that exom moons open wider or open for the first time the door to to aliens so

more seriously academically studying all right let's let's look at like alien worlds like so um I think it's still pretty fringe to talk about alien life even like on Mars and the moons and so on you're kind of like you know it would be nice but imagine the first time dis discover a living organism that's going to change then then everybody will look like an idiot for not focusing everything on this cuz the the possibility of the things will it it's possible might it might be super boring it might be very boring bacteria but even

the existence of life elsewhere yeah some I mean that changes everything that means life is everywhere yeah if you knew now that in 5 years 10 years the first life would be discovered elsewhere you knew that in advance it would surely affect the way you approach your entire career as a especially someone Junior in astronomy you would surely be like well this is clearly going to be the direction I have to dedicate my classes and my training and my education towards that direction all the new textbooks all the that's written I mean uh and I

think there's a lot of value to hedging like allocating some of the time to that possibility because the kind of Discovery we'll the kind of discoveries we might get in the next few decades um it feels what like we're on the verge of a lot of um uh getting a lot of really good data and having better and better tools that can process that data so there's just going to be a continuous increase of the kind of discoveries that will open like but a slam dunk that's hard to come by yeah I think a lot

of us are anticipating I mean we're already seeing it to some degree with Venus and the phosphine incident um but we've seen it before with Bill Clinton in the White House lawn announcing life from Mars and there there are inevitably going to be spous claims or at least claims which are um ambiguous to some degree there will be for sure a high-profile Journal like nature or science that will one day publish a paper saying VI a signature discovered or something like that on trapis one or some other planet and then there will be years of

back and forth in the in the literature and that might seem frustrating but that's how science works it's you know that's the mechanism of science at play of people scrutinizing the results to intense skepticism and it's like a crucible you know you burn away all irrelevances until whatever is left is the truth and so you're left with this this product which is that okay we either believe or don't believe that VI signatures are there so there's inevitably going to be a lot of controversy and debate and argument about it we just have to anticipate that

and so I think you have to basically have a thick skin to some degree academically to dive into that world and you're seeing that with um with phosphine it's been uh it's it's been uncomfortable to watch from the outside the kind of dialogue that some of the scientists have been having with each other about that because um they get a little aggressive yeah and you can you can you can understand why because jealousy I don't know I that's me saying not you that's me talking that I'm sure there's I'm sure there's some envy and jealousy

involved um on the on the behalf of those who are not part of the Discovery but there's also in any case just leave you know the particular people of involved in Venus alone in any case of making a claim of that magnitude yeah especially life because life is pretty much one of the biggest discoveries of all time you can imagine scientifically um you can see and I'm so conscious this in myself when I get close to as I said even the much smaller goal of setting an exomoon the ego creep in and so as a

scientist we have to be so guarded against our own egos you see the lights in your eyes of a Nobel Prize or um the the fame and fortune and being Remembered in the history books and we all grew up in our training learning about Newton and Einstein these Giants of the field Fineman Maxwell and you get the idea of these individual contributions which get immortalized for all time and that's seductive it's why many of us with the skill set to go into maybe banking instead decided actually there's something about the idea of being immortalized and

contributing toward Society in a permanent way that is more attractive than the financial reward of applying my skills elsewhere so to some degree that ego can be a benefit because it brings in skillful people into our field who might otherwise be tempted by money elsewhere but on the other hand it the closer you get towards when you start flirting with that Nobel Prize in your in your eyes so you think you're on the on the verge of seeing something you can lose objectivity a very famous example of this is uh Barnard star there was a

planet claimed there by Peter vaner Camp I think it was in 1968 69 and at the time it would have been the first ever exop planet ever claimed and um he he felt assured that this planet was there he was actually using the wobbling star method but using the positions of the Stars to see them to claim this exoplanet it turned out that this planet was was not there subsequent analyses by both dynamicists and theorists and those looking at the instrumental data established fairly um unanimously that there was no way this planet was really there

but Peter vaner Camp insisted it was there despite overwhelming evidence that was occuring against him um and even to the day he died which was I think like n in the early '90s he was still insisting this planet was there even when we were starting to make the first genuine exop planet discoveries and even at that point I think Hubble had even looked at that star and had totally ruled out any possibility of what he was talking about and so that's a problem how do you get to a point as a scientist where you just

can't accept anything that comes otherwise because you're it starts out with the the dream of Fame and then it ends in a stubborn refusal to ever back down of course the flip side of that is sometimes you need that to have the strength to carry a belief against the entire scientific community that resists your beliefs and so it's it's a double-edged sword that can happen but it I guess the the distinction here is evidence yes so in this case that the evidence was so overwhelming it wasn't really a matter of um interpretation it was it

was you had collect You' observe this star with the same um the same star but with maybe 10 even 100 times greater Precision for prolonged much longer periods of time and there was just no doubt at this point this planet was was a mirage um and so that's why you have to be very careful he say don't ever name you know my my wife and my daughter like name this planet after me that you discover and like I can't I can't ever name a planet after you because I'll be I won't be objective anymore how

could I ever how could I ever turn around to you and say that planet wasn't real that I named after you so you're somebody that talks about and is it's clear in your eyes and in your way of being that you love the the process of discovery that Joy the magic of just uh you know uh seeing something new observation a new idea right um but I guess the point is when you have that great feeling is to then switch on the skepticism like to start like testing um what does this actually mean is is

this real what are the possible uh different interpretations that could make this a lot less Grand than I first imagined and so both have the wander and the skepticism all in one brain yeah I think the generally the more I want something to be true the more I inherently doubt it and I think that just comes from you know I I grew up um with a religious family and was just sort of indoctrinated to some degree like many children are that okay this just normal that you know this a God and this is the way

the world is uh God created the Earth and then as I became more you know well read and literate of of what was happening in the world scientifically I started to doubt and it really just struck me that the hardest thing to let go of when you when you do decide not to be religious anymore and it's not really like a light bul moment but it just kind of happens over my over sort of 11 to 13 I think for me was happening but it's that sadness of letting go of this beautiful dream which you

had in your mind of eternal life for you know for for behaving yourself on Earth you would have this beautiful Heaven that you could go to and live forever and that's very attractive and for me personally um that was one of the things that pulled me against it was this it's it's like it's too good to be true and that it's very convenient that this could be um this could be so and I have no evidence directly in terms of a scientific sense to support this hypothesis and it just became uh really difficult to reconcile

um my growth as a scientist and I know some people find that reconciliation I I have not maybe I will one day um but as a general guiding principle which I think I I obtained from that experience was that I have to be extremely guarded about what I want to be true because it's going to sway me to say things which which are not true if I'm not careful and that's the that's not what we're trying to do as scientists so you felt from a religious perspective that there was um a little bit of a

gravitational field in terms of your opinions like it was affecting how you could be as a scientist like as a as a scientific thinker obviously where you're young yeah I I think um I I think that's that's true that whenever you're when whenever there's something you want to be true it's it's the ultimate seduction intellectually and I worry about this a lot with um with you know UFOs and with um it's it's true already with things like Venus phosphine and uh searching for astrological signals we have to guard against this all the way through from

however we're looking for life however we're looking for whatever this big question is there is a part of us I think I would love there to be life in the universe um I hope there is life in the universe but um I'm somewhat uh been on record several times as being fairly firm about trying to remain consciously agnostic about that question I don't want to make up my mind about what the answer is before I've collected evidence to inform that decision that's how science should work if I already know what the answer is then what

am I doing and that's not a scientific experiment anymore you've already decided so what are you trying to learn what's the point of doing the experiment if you already know what the answer is there's no point it's so complicated because so if I'm being honest with myself when I imagine the universe so F first thing I imagine uh about our world is that we humans and me certainly as one particular human uh no very my first assumption is I know almost nothing about how anything works so first of all that actually applies for for things

that humans do know like uh you know quantum mechanics and all the things that there's different expertises that I just have not dedicated to so even even that starting point but if we take all of knowledge as human civilization we know almost nothing that's kind of an assumption I have CU it seems like we keep discovering Mysteries and it seems like history human history is defined by moments when we said okay we pretty much figured it all out and then you realize a century later You' when you said that you didn't figure out anything okay

so that's like a starting point the second thing I have is I feel like the entirety of the universe is just filled with alien civilizations statistically there's the important thing that enables that belief for me is that they don't have to be humanlike they can be anything MH and it's just the fact that life exists and just seeing the way life is on Earth that it just finds a way it finds a way in so many different complicated environments it finds a way whatever that force is that same Force has to find a way elsewhere

also but but then if I'm also being honest and I I don't know how many hours in a day I spend seriously considering the possibility that we're alone mhm I don't know when I'm when I when my heart is and mind are filled with wander I think about all the different life that's out there but to really imagine that we're alone like really imagine all the vastness that's out there were alone that not even bacteria I would say you don't have to believe that we are alone um but you have to admit it's a possibility

of our ignorance of the universe so far um you can have a belief about something in absence of evidence and car haen famously describe that as the definition of faith if you believe something when there's no evidence you have faith that there's life in the universe but you can't you can't demonstrate you can't prove it mathematically you can't show me evidence of that um but is there some so mathematically math is a funny thing is there I mean the way physicist think like intuition so so basic reasoning is there some value to that well I'd

say we there's certainly you can certainly make a very good argument I think you've kind of already made one just the vastness of the universe is is the is the default argument people often turn to that surely there should be others out there it's hard to imagine um there are of order of 10 to the 22 stars in our observable universe and so really the question comes down to what is the probability of one of those 10 to 22 planets let's say earthy planets if they all have earthy planets um going on to form life

spontaneously that's the process of a Genesis the spontaneous emergence of life also the word spontaneous is it funny well okay maybe we w't use spontaneous but um um not not being to say uh seeded by so some some other civilization or something like this it naturally emerges cuz even the word spontaneous makes it seem less likely yeah like there there just this chemistry an extremely random process it could be a very gradual process over millions of years of growing complexity in in chemical networks maybe there's a force in the universe that pushes it towards interesting

complexity pockets of complexity that ultimately creates something like life which we can't possibly Define yet and sometimes it manifests itself into something that looks like humans but it could be a totally different kind of computational information processing system that we too dumb to even visualize yeah I mean certainly I mean it's kind of weird that complexity develops at all right because um it seems like the opposite to our physical intuition if you're training in physics of entropy that things should you know complexity is hard to spontaneously I shouldn't say spontaneously but hard to emerge in

general um and so that's an interesting problem I think uh there's been certainly from an evolutionary perspective you do see growing complexity and there's a nice argument I think it's by gold who who shows that if you have a certain amount of complexity um it can either become less complex or more complex through random mutation and the less complex things are are stripping away something something that was necessary potentially to their survival and so in general that's that's going to be uh not particularly useful in its survival and so it's going to be detrimental to

strip away a significant amount of its useful traits whereas if you add something the most uh typical thing that you add is probably not useful at all it's probably just uh doesn't really affect it survival negatively but it neither does it provide any significant benefit um but sometimes on rare occasions of course it will be of benefit and so if you have a certain level of complexity it's hard to go back in complexity but it's fairly easy to go forward with enough bites at the Cherry you will eventually build up in complexity and that's tensively

why we see complexity grow in in in certainly in an evolutionary sense um but also perhaps is operating in chemical networks that led to the emergence of life I guess the the real uh problem I have with the with the numbers game just come back to that is that we are talking about a certain probability of that occurring it may be to go from the primordial soup however you want to call it the ingredients that the earth started with the organic molecules the probability of going from that initial condition to something that was capable of

darwinian natural selection that maybe we could Define as life um the probability of that is maybe 1% 1% of the time that happens in which case you're right the universe will be absolutely teeming with life but it could also be uh 10 the^ minus 10 in which case it's one per Galaxy or 10 the^ of minus 100 in which case the vast majority of universes even do not have life within it or 90% or 90 you said 1% you said 1% but it could be 90% if the conditions the chemical conditions of a planet are

correct or a moon are correct I admit that it could be any of those numbers and the challenge is we just have no rigorous reason to expect why 90% is any because we're talking about a probability of a probability MH what's is is 90% more aior likely than 10 the^ minus 20 well the thing is we do have an observation n of one of Earth mhm and uh it's difficult to know what to do with that what kind of intuition you build build on top that because on Earth it seems like life finds a way

okay in all kinds of conditions in all kinds of crazy conditions good and it's able to like build up from the basic chemistry you could say okay uh maybe it takes a little bit of time to develop some complicated technology like mitochondria I don't know like photosynthesis fine but it seems to figure it figure it out and like do it extremely well yeah but I would say you're describing a different process I mean um maybe I'm I'm at fault for separating these two processes but to me you're describing basically natural selection Evolution at that point

um whereas I'm really describing AOG Genesis which is to me a separate distinct process do you limited human scientists yes but why would it be a separate process why why is the birth of Life a separate process from the process of Life uh like why is the I mean we're uncomfortable with the F we're uncomfortable with the big bang we're uncomfortable with the first thing I think like where did this come from right so I think I would say I just twist that question right say what you're saying why is it a different process um

why and I would say why shouldn't it be a different process which isn't really a good defense except to say that we we we have we have knowledge of how Natural Evolution natural selection Evolution works we think we understand that process we have almost no information about the earlier stages of how life emerged on our planet it may be that you're right and it is part of a Continuum it may be that is also a distinct improbable set of circumstances that led to the emergence of Life as a scientist I'm just trying to be open-minded

to both possibilities if I assert that life must be everywhere to me you run the risk of experimented bias um if you think you know what the answer is if you look at an earthlike planet and you and you are preconditioned to think there's a 90% chance of Life on this planet it's going to at some level affect your interpretation of that data whereas if I however critical you might be of the agnosticism that I impose upon myself remain open to both possibilities then I trust in myself to make a fair assessment as to the

reality of that evidence for life yeah but I I wonder sort of scientifically and and that's really beautiful to hear and inspiring to hear uh I I wonder scientifically how many firsts we truly know of like and then we don't eventually explain as as as actually uh a a a step number 1 million in a long process so I think that's a really interesting thing if there's truly first in this universe like you know for us the B whatever happened at the bing bang is is a kind of first the origin of stuff but it

just again um it seems like history shows that we'll figure out that it's actually a continuation of something but then physicists say that time is emergent and there causality and times is is a very human kind of construct that it's very possible that all of this so there could be really firsts of a thing to which we attach a name so whatever we call Life maybe there is an origin of it yeah and I would also say I'm open to the idea of it being part of a continuation but the continuation Maybe is more broader

and it's a continuation of chemical systems and chemical networks and the what we we call this one particular type of chemistry in this behavior of chemistry life um but it is just one manifestation of all the trillions of possible permutations in which chemical reactions can occur and we we assert specialness to it because that's what we are and so this is it's also true of intelligence you could extend the same thing and say you know we're we're looking for intelligent life in the universe and you sort of where does where do you define intelligence where

where's that Continuum of of something that's really like us are we alone there may be a Continuum of chemical systems a Continuum of intelligences out there and um we have to be careful of our own arrogance of of assuming specialness about what we are that we are some distinct category of phenomena whereas the universe doesn't really care about what category we are it's just doing what it's doing and doing everything in you know infinite infinite diversity and infinite combinations is essentially what it's doing and so we are we are taking this one slice and saying

No this has to be treated separately and um I I'm open to the idea that it could be a truly separate phenomena but it may just be like a like a snowflake every snowflake is different it may just be that this one particular iteration is another variant of the vast Continuum yeah maybe the algor them of natural selection itself is an invention of Earth I kind of also tend to suspect that this this whatever the algorithm is it kind of operates at all levels throughout the Universe mhm but maybe this is a very kind of

peculiar thing that um where there's a bunch of chemical systems that compete against each other somehow for survival under limited resources and that's a very earthlike thing mhm we have a nice balance of there's a large number of resources enough to have a bunch of different kinds of systems competing but not so many that um they they get lazy yeah and maybe that's why bacteria were very lazy for a long time maybe they had they didn't have much competition quite possibly I mean I I tried to as as fun as it is to get into

the speculation about um the definitions of of life and what life does and this this gross network of possibilities honestly for me the strongest argument for remaining agnostic is is to avoid that that bias and assessing data and we've SE we've seen it I mean person LOL I talked about my channel um and maybe last year or two years ago you know he's a very famous astronomer who in the 19th century was claiming the evidence of canals on Mars and from him from his perspective and even at the time culturally it was WI accepted that

Mars would of course have life I mean I think it's uh seems silly to us but it was kind of similar arguments to what we're using now about exoplanets that well of course there must be life in the universe how could it just be here and so it seemed obvious to people that when you looked at Mars with its polar caps even you know its atmosphere had Seasons it seemed obvious to them that that too would be a place where life Not only was present but had emerged to a civilization which actually was fairly comparable

in technology to our our own because it was building Canal systems um of course a canal system seems a bizarre techno signature to us but it was a product of their time to them that was The Cutting Edge in technology it it should be a warning shot actually a little bit for us that if we think you know solar panels or building star links or whatever space mining is like an inevitable techic signature that may be laughably Antiquated compared to what other civilizations far more advanc than us may be doing and so anyway personal L

he was he I think was a product of his time that he thought life was inevitably he even wrote about it extensively and so when he saw these lines these L on the surface of Mars to him it was just obvious they were canals and he was he that was experimented bias playing out he was told for one that he had basically the greatest eyesight um out of any of his peers and Opthomologist had told him that in Boston that his eyesight was you know absolutely spectacular so he just was convinced everything he saw was

was real um and secondly he was convinced there was life there and so it to him it just added and then that kind of wasted you know Decades of research of of treating the idea of Mars being inhabited by this canal civilization um but on the other hand it's maybe not a waste because it is a lesson in history of how we should be always on guard against our own preconceptions and biases about what whether life is out there and furthermore what types of things life might do if it is that if I were running

this simulation which we'll also talk about because you make the case against it but if IUN running a simulation I would definitely put you in a room with an alien and just to see you mentally freak out for hours at a time you for sure would have thought you will be convinced that you've lost your mind I mean no not not not that but I mean like if we discover Life we discovered interesting new physical phenomena I think the right approach is definitely to be extremely skeptical and be very very careful about things you want

to be true that's that's really I would say not I'm not like some extreme denialist of of evidence if there was if there was compelling evidence for life on another planet I would be the first one to be celebrating that and be shaking hands with the alien on the White House lawn whatever that would be you know I grew up with Star Trek and that was my fantasy was to you know be Captain Kirk and fly across the Stars meaning at the civilization so there's nothing more I'd want to be true as I've said but

um we we just have to guard against it when we're we're assessing data um but uh I'm I have to say I'm very skeptical that we will ever have that uh Star Trek moment even if even if there are other civilizations out there they're never going to be at a at a point which is in technological lock step with us similar level development even uh intellectually the idea that they could uh have a conversation with us even through a translator I mean we can't communicate with humback whales we can't get with dolphins in a meaningful

way we can sort of bark orders at them but we can't uh have abstract conversations with them about things um and so the idea that we will ever have that fulfilling conversation I'm deeply skeptical of and I think a lot of us are drawn to that it is maybe a replacement for God to some degree that that Father Figure civilization that might step in teach us the a of our ways and bestow wisdom Upon Our civilization but they could equally be a giant fungus that has doesn't even understand the idea of social socialization because it's

the only entity on it Planet it just swells over the entire surface and it doesn't it's incredibly intelligent because maybe each node communicates with each other to create essentially a giant neuronet but it has no sense of what communication even is and so alien life is out there is surely going to be extremely diverse I'm pretty skeptical that we'll ever get that that fantasy moment I always had as a kid of having a dialogue within the civilization so dialogue uh yes what about noticing them what about noticing signals do you hope so one thing we've

been talking about is getting signatures bio signatures technos signatures about other planets maybe uh if we're extremely lucky In Our Lifetime to be able to meet life forms uh get evidence of living or dead life forms on mars or the moons of Jupiter and Saturn what about getting signals from out of space Interstellar signals uh what kind of what would those signals potentially look like um that's a hard question to answer because we are we essentially engaging in xenos Psychology to some degree what are the activities of another civilization a lot of that is what

do the word xenos psychology apologize to interrupt mean well maybe I'm I'm just fabricating that word really but they trying to guess at the um the machinations and motivations of another intelligent being that was completely evolutionary divorced from us so it's like like you said exom moons it's exop psychology extra solar yeah psychology yeah uh Alien psychology is another way of maybe making it more grounded but um the it it we we can't really guess at their their motivations too well but we can look at the sorts of behaviors we engage in and at least

look for them um we're always guilty that when we look for bios signatures we're really looking for and even when we look for planets we're looking for templates of earth when we look for bios signatures we're looking for templates of earth-based life when we look for tchis signatures we tend to be looking for templates of our own behaviors or extrapolations of our Behavior um so ex we there's a very long list of tenis signatures that people have suggested we could look for the earliest ones were of course radio beacons that was sort of project osma

that Frank Drake was involved in um trying to look for radio signatures which could either be um just like blurting out high power radio signals saying hey we're here or could even have encoded within them Galactic encyclopedias for us to unlock which has always been the aore of the radio Tech technique um but there could also be unintentional signatures um for example you could have something like the satellite system that we've produced around the earth the artificial satellite system starlink uh type systems we mentioned you could detect the glint of light across those satellites as

they orbit around the planet um you could detect a geostationary satellite belt which would block out some light as the planet transited across the star you could detect solar panels potentially spectrally on the surface of the planet Heat Island effects New York is hotter than New York state by a couple of degrees because the heat island effect of the city and so you could thermally map different planets and detect these so there's a large array of things that we do that we can go out and hypothesize we could look for and then on the furthest

end of the scale you have things which go far beyond our capabilities such as um warp drive signatures which have been proposed you get these bright flashes of light or even gravitational wave detections from ligo could be protected um you could have Dyson spheres the idea of covering it basically a star is completely covered by some kind of structure which collects all the all the light from the Star to power the civilization and that would be pretty easily detectable to some degree because you're you're transferring all of the visible light thermodynamically it has to be

reemitted so it come out as infrared light so you'd have an incredibly bright infrared star yet one that was visibly not present at all and so that would be pretty intriguing signature to look for well is there efforts to look for something like that for for for D spares out there for with with the strong infrared signal there has been yeah there has been and there's been uh I think in the literature there was one with the IRAs satellite which is an infrared satellite they targeted I think of order of 100,000 Stars uh nearby stars

and found no convincing examples of what looked like a Dyson Sphere star and then Jason Wright and his team um Extended this I think using wise which is another infro satellite um to look around galaxies so could an entire galaxy have been converted into Dyson spheres or a significant fraction of the Galaxy which is basically the uh the kardashev type three right this is the when you've basically mastered the entire Galactic pool of resources and uh again out of a 100,000 nearby galaxies there appears to be no compelling examples of what looks like a Dyson

Galaxy if you want to call it that um so that by no means uh proves that they don't exist or don't happen but it seems like it's an unusual behavior for a civilization to get to that stage of development and start harvesting the entire Stellar output unusual yes I and I mean ligo is super interesting with gra with gravitational waves if that kind of experiment could start seeing some weirdness some weird signals some that compare to the to the power of cosmic phenomena yeah yeah yeah I mean it's a whole new window to the universe

not just in terms of astrophysics but potentially for Technic signatures as well I have to say with the with the warp drives I am skeptical that warp drives are possible because you have you have kind of fundamental problem relativity you can either really have relativity faster than light travel or causality you can only choose two of those three things you really can't have all three in a coherent Universe if you have all three you basically end up with the possibility of these kind of temporal paradoxes and time loops and grandfather paradoxes well can't there be

pockets of causality something like that like where there's uh like pockets of consistent causality you could design it in that way you could be you know if you had a warp drive or a time machine essentially you could be um Cog you know you could be very conscious and careful of the way you use it so as to not to cause paradoxes or just do it in a local area or something but the real fundamental problem is you always have the ability to do it and so in a in a vast Cosmic Universe if time

machines were all over the place uh that there's too much risk of someone doing it right of somebody having the option of of essentially breaking the universe with it this so this is a fundamental problem Hawking uh has this chronology protection conjecture where he said that essentially that it's this just can't be allowed because it breaks it breaks all our laws of physics if time travel is possible current laws of physics yes correct yeah um and so we' need to rip up relativity I mean that's the point it's the current laws of physics so you'd

have to rip up our current law of relativity to make sense of how FTL could live in that Universe because you can't have relativity FTL and causality sit nicely and play nicely together but we're currently don't have quantum mechanics and relativity playing nice together anyway so it's not like everything is all a nice little fabric it's certainly not the full picture there must be more to go but um so it's already ripped up so might as well rip it up a little more and and in the process actually try to connect the two things cuz

maybe in the unification of uh of the standard model and uh general relativity maybe there lies some kind of new wisdom about of about warp D so by the way warp D is somehow messing with the fabric of the universe to be able to travel fast than the speed of light yeah you're basically bending SpaceTime you could also do it with a wormhole or attack you know some of the hypothetical ft say doesn't have to necessarily be uh the bear Drive the warp drive it could be any fast than light system as long as it

travels super luminally it will violate quality and presumably that will be observable with Lego uh potentially yeah potentially depends on I think you know the properties of whatever the spacecraft is um I mean one one problem with war drives is there's all sorts of problems with war drives but but when like the start of that sentence one problem there's just this one minor problem that we have to get around but uh when it arrives at its destination it basically collects this vast uh B has like an event horizon almost at the front of it and

so it collects all the collects all this radiation at the front as it goes and when it arrives all that radiation gets dumped on its destination and would basically completely exterminate the planet it arrives at um that radiation is also incident within the shell itself there's Hawking radiation occurring within the shell which is pretty dangerous um and then you know also has it raises all sorts of exacerbations the firmy Paradox of course as well so you might be able to explain why we don't see um a Galactic Empire and even here is hard you might

be able to explain why we don't see a Galactic Empire if everybody's limited to Voyage or two rocket speeds of like 20 km per second or something but it's a lot harder to explain why we don't see the stars populated by Galactic Empires when warp drive is imminently possible because it makes expansion so much more trivial that um it it it makes our life harder um there's there's some wonderful simulation work being done out at Rochester where they actually simulate all the stars in the galaxy or or a fraction of them and they spawn a

civilization on one of them and they let it spread out at sublight speeds and actually the very mixing of the Stars themselves because the stars are not static they're in orbit of the galactic center and they have crossing paths with each other if you just have a range of even like five light years and you're speed is of order of a few per the speed of light is the maximum you can muster you can populate the entire galaxy within something like 100,000 two about a million years or so so know a fraction of the lifetime

of the Galaxy itself um and so this raises some uh fairly serious problems because if any civilization the entire history of the of the Galaxy decide to do that then you know either we shouldn't be here or we happen to live in this kind of rare pocket where they chose not to populate to and so this is sometimes called facte Hearts facte um as you know the facte is that a civilization is not here now an alien civilization has not is not in present occupation of the earth and that's difficult to resolve with the apparent

ease at which even a small extrapolation of our own technology could potentially populate a Galaxy in Far faster than Galactic history so to me by the way yeah the firm of paradox is truly a paradox for me but I suspect that if alien visited Earth I suspect if they do um if they are everywhere I think they're already here and we're too dump to see it but leaving that aside I think we should be able to in that case have very strong obvious signals when we look up at the stars at the emanation of energy

required we would see we would see we would see some weirdness that like where these are these kinds of stars and these are these kinds of stars that are being messed with like leveraging the nuclear fusion of stars to do something useful like the fact that we don't really see that like maybe you can correct me wouldn't we be able to if if there is like alien civilizations running galaxies wouldn't we see weirdnesses uh from an astronomy perspective with the with the way the stars are behaving yeah I mean it it depends exactly what they're

doing but I mean the Dyson Sphere example is one that we already discussed where a serve of 100,000 nearby galaxies find that they are not have all been transformed into Dice and sphere collectors um you could also Imagine them doing things like we already paper this recently star lifting where you can extend the life of your Star by scooping Mass off the star so you'd be you know doing Stellar engineering essentially um space if you're doing a huge amount of asteroid mining uh you would have a spectral signature cuz you're basically filling the solar system

with dust by doing that there'd be debris from that activity and so there are um some limits on this um certainly we don't see uh you know bright flashes which would be you know one of these consequences W drives as I said is as they decelerate they produce these bright flashes of light we don't seem to see evidence of those kind of things um we don't see anything obvious around the nearby stars or the stars that we've serveed in detail be beyond that that indicate any kind of artificial civilization the closest maybe we had was

bagin star there was a lot of interest in there was a star that was just very peculiarly dipping in and out his brightness and it was hypothesized for a time that that may indeed be some kind of um Dyson like structure so maybe a Dyson Sphere that's half built and so as it comes in and out it's blocking out huge swaths of the star it was very to explain it really with um any kind of planet model at the time um but an easier hypothesis that was proposed was it could just be a large number

of comets or dust or something or maybe a planet that had broken apart and as its fragments orbit around it blocks out Starlight and it turned out um with subsequent observations of that star which especially the amateur astronomy Community made a big contribution to as well um that the the dips were chromatic which was a a real important clue that that probably wasn't a solid structure then that was going around it it was more likely to be dust dust is chromatic by chromatic I mean it looks different in different colors so it blocks out more

red light than blue light if it was a solid structure shouldn't do that it's it it shouldn't be it should be opaque right a solid metal structure or something so that was one of the clear indications and and the the behavior of in the way the light changed or the dips changed across wavelength was fully consistent with the expectations of what small particulates would do um and so that's that's very hard I mean the real problem with alien hunting the real technal this is this is the real the one problem the one problem with the

war drive and the one problem with alien hunting yes but well actually I'd say there's three big problems for me with any search for life which includes UFOs all the way to fossils and Mars is that aliens have three unique properties as a hypothesis one is they have essentially unbounded explanatory capability so there's almost no phenomena I can show you that you couldn't explain with aliens to some degree you could say well the aliens just have some super high-tech uh way of creating that illusion um the second one would be unbounded avoidance capacity so I

might see a UFO tomorrow or and then the next day and then the next day and then predict I should see it on Thursday at the end of the week but then I don't see it but I could always get out of that and say well that's just because they chose not to come here you know they have this they can always avoid future observations fairly e easily um if you survey an exoplanet for Bio signatures and you don't see oxygen you don't see methane that doesn't mean there's no one living there they could always

be either tricking their atmosphere engineering it we actually wrote a paper about that how you can use lasers to hide your bios signatures as an advanced civilization um or you could just be living underground or under water or something where there's no bio signatures so you can never really disprove there's life on another planet or on another star it's has infinite avoidance and then finally the third one is that that we have incomplete physical understanding of the universe so if I see a new phenomena which Bo Ain star was a good example of that we

saw this new phenomena of these strange dips we've never seen before it was hypothesized immediately this could be aliens it's like a god of the gaps but it turned out to be incomplete physical understanding and so that happens all the time in the first PSA that was discovered same story um Joselyn Bell kind of somewhat tongue and cheek called it little green man one because it looked a lot like the radio signature that was expected from an alien civilization but of course it turned out to be a completely new type of star that we had

never seen before which was a neutron star um with these two Jets coming out the top of it and so um that's a challenge those three things are really really difficult in terms of experimental design for a scientist to work around something that can explain anything can avoid anything so it's almost unfalsifiable and could always just be to some degree as you said we have this very limited knowledge of the infinite possibilities of physical law we're probably only scratching the surface each time and we've seen it so often his in history we may just be

detecting some new phenomena well that last one I think um a little more okay with making mistakes on yeah which is because it's exciting still but because no matter so you might exaggerate the importance of the discovery but the whole point is to try to find stuff in this world that's weird and try to characterize that weirdness sure you can throw Little Green Men as a label on it but eventually it like it's as mysterious and as beautiful as as interesting as a little GRE like we we tend to think that there's some kind of

threshold but like there's all kind kinds of weird organisms on this Earth that operate very differently than humans that are super interesting uh the human mind is super interesting I mean like uh weirdness and complexity is is as interesting in any of its forms as what we might think from Hollywood what aliens are so like that that's that's okay looking for weirdnesses on Mars that's one of the best STS pitches to do Technic signature work is that you know we always have that as our fullback that like we're going to look for alien signatures if

we fail we're going to discover some awesome new physics along the way and so even a uh even any kind of signature that we detect is always going to be interesting um and so that that compels us to um have not only the question of looking for life in the universe but it can it gives us a strong scientific grounding as to why this sort of research should be funded and should be executed because it always pushes the frontiers of knowledge I wonder if we'll be able to discover and be open enough to a broad

definition of aliens where we see some kind of technos signature basically like a touring test like this thing is intelligent M like it's processing information in a very interesting way MH but but you can say that about chemistry you could say that about physics maybe not physics chemistry like interesting complex chemistry you could say that this is processing this is storing information this is propagating information over time it's I mean I want I it's a gray area between a living organism that we would call an alien and I thing that's super interesting is able to

carry some kind of intelligence yeah in information is a really useful way to frame what we're looking for though because it then you're then you're divorced from making assumptions about even a civilization necessarily or anything like that so any kind of information Rick signature indeed you can take things like the light curve from bajin star and ask what is the minimum number of free parameters or the minimum information content that must be encoded within this light curve and the hope is that maybe from you know a good example be from a radio signature you detect

something that has you know a thousand megabytes of of parameters essentially contained within it that's pretty clearly at that point not the product of a natural process or least any natural process that we could possibly imagine with our current understanding of the universe and so thinking even if we can't decode which actually I'm skeptical we'd be able to ever decode it in our lifetimes it would probably take decades to fully ever figure out what they're trying to tell us um but if there was a message there we could at least know that there is high

information content and there is complexity and that this is a attempt at communication and information transfer and leave it to our subsequent generations to figure out what exactly it is they're trying to say what again a wild question and thank you for uh entertaining them entertaining them I really really appreciate that um but what kind of signal in our lifetime what kind of thing you do you think might happen could possibly happen where the scientific Community would be convinced that there's alien civilizations out there like what uh you already said maybe a strong infrared signature

for something like a Dyson Sphere that yeah that's Poss that that's also to some degree a little bit ambiguous um because that's that's a Challen interrupt is where your brain would be like you as a scientist would be like I know it's ambiguous but this is really weird yeah I think if he had something I can imagine something like a prime number sequence or mathematical sequence like the Fibonacci series something being broadcast mathematically provable that this is not a physical phenomenon right I mean yeah prime numbers is a pretty good case because there's no natural

phenomena that produces prime number sequences it seems to be a purely an abstract mathematical concept as far as I'm aware and so if we detected uh you know a series of radio blips that we following that sequence it would be pretty clear to me or it could even be uh you know car say can suggested that Pi could be encoded and that or you might use the hydrogen line but multiply by pi like some very specific uh frequency of the universe like a hydrogen line but multiply it by a abstract mathematical constant that would imply

strongly that there was someone behind the scenes operating that um sorry stored in which phenomena though that of a radio wave but the information I mean we kind of toyed with this um uh idea and a video I did about hypothetical civilization on my channel but one kind of fun way I I do want to bring the this conversation towards time a little bit and thinking about um not just looking for life and intelligence around us right now but looking into the past and even into the future to some degree or communicating with the future

and so we had this fun experiment of imagining a civilization that was born at the beginning of the history of the Galaxy and being the first and what it would be like for them and they were desperately searching for evidence of life but couldn't find it and so they decided to try and leave something behind for future civilizations to discover to tell them about themselves but of course a radio signature is not going to work there because it has have a power source and that's a piece of Machinery it's going to eventually break down it's

going to be hard to maintain that for billions of years time scale and so you wanted something that was kind of passive that doesn't require an energy source but can somehow transmit information which is hard to think about something that satisfies those criteria but there was a proposal by one of my colleagues Luke Arnold which uh inspired a lot of us in technis signatures and he suggested that you could build artificial transitors so you could be build she sheets of material that transit in front of the star maybe one uh thin sheet passes across first

then two then three then five seven so you could follow the primary number sequence of these and so there'd be a clear indication that someone had manufactured those but they don't require any energy source because they're just sheets of material in Orit of the star they would eventually degrade from microm meteorites and maybe they always would become destabilized but they should have lifetimes far exceeding the lifetime of any uh battery or mechanical electronic system that we could at least without technology conceive of building and so you can imagine then extending that and how could you

encode not just a prime number sequence but maybe in the spatial pattern of this very complex light curve we see you could encode more and more information through 2D shapes and the way those occations happen and maybe uh you could even encode uh messages and and in-depth information from you know you could even imagine it being like a a lower layer of information which is just the prime number sequence but then you look closely and you see there's smaller divots embedded within those that have a deeper layer of information to extract um and so to

me something like that would be pretty compelling that that was somebody who would manif unless it's just a very impressive hoax um that would be a pretty compelling evidence for the civilization and actually the methods of uh astronomy right now are kind of marching towards being able to better and better detect a signal like that yeah I mean to some degree it's just building bigger aperture in Space the bigger the telescope the the finer ability to detect those minute signals do you think the current of the scientific Community another weird question but just the observations

that are happening now do you think they're ready for a prime number sequence in in the um so if if we're using the the current method the transit timing variation method like do you think you're ready do you have the tools to detect the prime number sequence yeah for sure I mean there's two 200,000 stars that kept them monitored and it monitored them all the time it took a photo of each one of them every 30 minutes measured their brightness and it did that for four and a half years and so you have already and

Tessa is doing it right now another mission and so you have already an existing catalog and people are uh genuinely scouring through each of those light curves with Automated machine learning techniques we even developed some in our own team that can look for weird Behavior we wrote a code called the weird detector for instance that you know it was just the most generic thing possible let don't assume anything about the signal shape just look for anything that repeats the signal shap can be anything and we kind of learn the template of the signal from the

data itself and then we it's like a template matching filter to see if that repeats many many times in the data and so we actually applied that and found a bunch of interesting stuff but we didn't see anything that was the prime number sequence at least on the Kepler data that's 200,000 Stars which sounds like a lot but compared to 200 billion stars in the Milky Way it's really just scratching the surface so one because there could be something much more generalizable than the prime number sequence it's ultimately the question of a signal that's very

difficult to compress in the general sense of what compress means so maybe as we get better and better machine learning methods that automatically figure out analyze the data to to understand how to compress it just you'll be able to discover data that's for some reason is not compressible but then a you know know compression really is a bottomless pit because like that's really what intelligence is is being able to compress information yeah and and to some degree the more you I would imagine I don't work in compression algorithms but I would imagine the more you

compress your signal um the the more assumptions that kind of go on behalf of the decoda the more skilled they really have to be you know some of the a prime number sequence is completely unencoded information essentially but um if you look at the AR Rebo message they were fairly careful with their pixelation of this simple uh image they sent to try and make it as interpretable as possible to be that even a dumb alien would be able to figure out what we're trying to show them here because there's all sorts of conventions and rules

that are built in that we we tend to presume when we design our messages and so if your messages assuming they know how to do an MP3 decoder particular uh compression algorithm I'm sure they could eventually reverse engineer it and figure it out but you're you're making it harder for them to get to that point so maybe I always think you you probably would have a two-tier system right you'd probably have some lower tier key system and then maybe beneath that you'd have a deeper compressed layer of more in-depth information what about maybe observing physical

actual physical objects so first let me go to your Tweet as a source of inspiration you tweeted that it's interesting to ponder that if or clouds are ever mined by the systems ofan civilizations mining equipment from billions of years ago could be in our or Cloud since the or clouds are they they they extend really really really really far outside the the the actual star yeah um that so you know mining equipment just basic boring mining equipment out there I don't know if there's something interesting to say about or clouds themselves that that are interesting

to you and about possible non shiny uh light emitting mining equipment from Alien civilization yeah I mean that thought I mean that's kind of the beauty of the field of techno signatures and looking for life is you can find inspiration and intellectual joy in just the smallest little thing that starts a whole thread of building upon it and wondering about the implications and so in this case I was just really struck by we kind of mentioned this a little bit earlier the idea that stars are not static we tend to think of the Galaxy as

having stars in a certain location from the center of the Galaxy and they kind of live there but in truth the stars are not only orbiting around the center of the Galaxy um but those orbits are themselves changing over time they're processing and so in fact the orbits look more like a spirograph if you ever done those as a kid it kind of whirl around and Trace out all sorts of strange patterns and so there Stars intersect with one one another and so uh the current closest star to us is proximus centu which is about

4.2 light years away but it will not always be the closest star and over millions of years it will be supplanted by other stars in fact stars that will come even closer than Proxima within just a couple of light years and that's been happening not just we can project that will happen over the next few million years but that's been happening presumably throughout the entire history of the Galaxy for billions of years and so if you went back in time it you know there would have been all sorts of different nearest Stars right different stages

of the Earth's history and those stars are so close that their or clouds um do intermix with one another so the or Cloud can extend out to even a light year or two around the earth there's some debate about exactly where it ends it probably doesn't really have a definitive end but kind of more just kind of Peters out more and more and more as you go further away by the way for people who don't know nor Cloud I don't know what the technical definition is but a bunch of rocks that kind of no objects

that orbit the the the star and they can extend really really far because of these are objects that probably are mostly icy Rich um they were probably formed fairly similar distances to Jupiter and Saturn but were scattered out through the interactions of those giant planets um we see a circular disc of objects around us which kind of looks like the asteroid belt but just further away called the Kyer belt and then further beyond that you get the or cloud and the or cloud is not a dis it's just a sphere it kind of surrounds Us

in all directions so these are objects that were scattered out through uh three-dimensionally in all different directions um and so those objects are potentially resources for us especially if you were planning to do an Interstellar mission one day you might want to mine the water that's embedded within those and use that as either oxygen or fuel for your rocket and so it's quite possible uh there's also some rare earth metals and things like that as well but it's quite possible that a civilization might use all Cloud objects as a jumping off point um or or

in the Kyper you have things like Planet 9 even that's there might even be objects Beyond in the OR Cloud which are actually planet likee that we just cannot detect these objects are very very faint so that's why they're so hard to see I mean even Planet 9 it's hypothesized to exist but we've not been able to confirm its existence because it's something like a thousand auu away from us thousand times the distance of the Earth from the Sun and so even though it's probably larger than the earth the amount of light it reflect from

the sun the sun is just looks like a star at that point so far away from it that it barely reflects anything back it's extremely difficult to detect so there's all sorts of Wonders that may be lurking out in the outer solar system and so this has leads you to wonder um you know in the OR Cloud that or Cloud must have intermixed with other or clouds in the past and so what fraction of the or cloud is truly belongs to us belongs to what was scattered from Jupiter and Saturn what fraction of it could

in fact be uh Interstellar visitors and of course we've got excited about this recently because of om mu mua this Interstellar asteroid which seemed to be at the time the first evidence of an Interstellar object but when you think about the or Cloud inter mixing um it may be that a large fraction of comets comets are seeded from the or Cloud that that eventually come in um some of those comets May indeed have been Interstellar in the first place that we just didn't know about through this process um there there even is an example I

can't remember the name there's an example of a comet that has a very peculiar spectral signature that has been hypothesized to have actually been an Interstellar visitor but one that was essentially sourced through this or Cloud mixing and so this is kind of intriguing um it also you know the outer solar system is just such a it's like the bottom of the ocean we know so little about what's on the bottom of our own planet's ocean and we know next to nothing about what in the outskirts of our own solar system it's all Darkness yeah

so like that that's one of the things is to understand the phenomena we need light and we need to see how light interacts with it or what light emanates from it but most of our universe is Darkness so it's there could be a lot of interesting stuff I me this is where your interest is with the with the cool worlds and interesting stuff lurks in the darkness right basically all of us you know 400 years of astronomy our only window into the universe has been light and that has only changed quite recently with the discovery

of gravitational waves that's now a new window and hopefully uh well to some degree I guess solar neutrinos we've been detecting for but they come from the certain Interstellar space but we may be able to soon detect neutrino messages has even been hypothesized as a way of communicating between civilizations as well or just do neutrino telescopes to um study the universe and so there's a growing interest in what we'd call multimessenger astronomy now so not just messages from light but messages from these other uh physical um packets of information that are coming our way uh

but when it comes to the outer Solar System Light really is our only window there's two there's two ways of doing that one is you detect the light from the or Cloud object itself which as I just said is very very difficult there's another trick which we do in the Kyer belt especially and that's called um an occultation and so sometimes those objects will just pass in front of a distant star just coincidentally these are very very brief moments they last for less than a second um and so you have to have a very fast

camera to detect them which conventionally astronomers don't usually build fast cameras most of the phenomena we observe occurs on hours minutes days even but now we're developing cameras which can take you know thousands of images per second um and yet do it at the kind of astronomical Fidelity that we that we need for this kind of precise measurement and so you can see uh these these very fast dips you even get the kind of defraction patterns that come around which are really cool to look at and that's I kind of love it cuz it's almost

like passive radar you're you have these pin Pricks of light imagine that you live in a giant black sphere but there's these little pin holes that have been poked and through those pin holes almost laser light is shining through and inside this black sphere there are unknown things wandering around drifting around that we are trying to discover and sometimes they will pass in front of those little pencil thin laser beams block something out and so we can tell that it's there and it's not an active radar because we didn't actually you know beam anything out

and get a reflection off which is what the sun does the sun's like comes off and it comes back that's more like an active radar system there more like a passive radar system where we are just listening very intently and so um I'm kind of so fascinated by that the idea that we could map out the rich architecture of the outer solar system just by doing something that could have done potentially for a long time ago which is just listening in the right way just just tuning Our instrumentation to the correct way of of not

listening but viewing the universe to catch those objects yeah I mean it's really fascinating It's seems almost obvious that your efforts when projected out in over like 100 200 years will have a really good map through even methods like basically Transit timing high resolution Transit timing but basically the planetary and the uh the planet satellite movements mhm that of all the different star systems out there yeah and it could revolutionize the way we think about the solar system I mean that revolution has happened several times in the past when we discovered Vesta in the 19th

century um that was I think the the seventh planet for a while or the eighth planet when it was first discovered and then we discovered series and there was a bunch of asteroid objects Janus and so for a while the textbooks had um there was something like 13 planets in the solar system and then they and then that was just a new capability that was emerging to detect those small objects and then we ripped that up and said no no we're going to change the definition of a planet and then the same thing happened when

we started looking the outer skirts of the solar system again we found Aris we found sedna these objects which resembled Pluto and the more and more of them we found make make and eventually we again had to rethink the way we even uh contextualize what a planet is and what the nature of the outer solar system is um so regardless as to what you think about the debate about whether Pluto should be demoted or not which I know often invokes a lot of strong feelings it is an incredible achievement that we were able to transform

our view of the solar system in a matter of years just by basically you know charge coupled devices the things that's in in cameras um those the invention of that device allowed us to detect objects which were much further away much fainter and revealed all stuff that was there all along and so it that's the beauty of astronomy there's just uh so much to discover and even in our own backyard do you ever think about this do you imagine what are the things that will completely change astronomy over the next 100 years like if you

transport yourself forward 100 years what are the things that will blow your mind when you look at wait what would it be just a very high resolution mapping of things like holy crap like one surprising thing might be holy crap there's like earthlike moons everywhere yeah and another one could be just totally different devices for sensing yeah I think you usually astronomy moves forward dramatically and Science in general when you have a new technological capability come online for the first time um and we kind of just gave examples of that there with the solar system

so what kind of new capabilities might emerge in the next 100 years the capability I would love to see is not just I mean we in the next 10 20 years we're hoping to take these pale blue dot images we spoke about so that requires building something like jwst but on even larger scale and optimized for direct Imaging you have to have either coronograph or a star shade or something to block out the staright and reveal those pale blue dots so in the next sort of decades I think that's the achievement that we can look

forward to in our lifetimes is to see photos of other Earths going beyond that maybe in our life towards the end of our lifetimes perhaps I'd love it if we I think it's technically possible as breakthrough star shot are giving us a lot of encouragement with to maybe send a small probe to the nearest stars and start actually taking high resolution images of these objects there's only so much you can do from far away if you want to have and we can see it in the solar system I mean there's only so much you can

learn about Europa by pointing h space telescope at it but if you really want to understand that that Moon you're going to have to send something to orbit it to hopefully land on it and drill down to the surface and so the idea of even taking a a flyby and doing a snapshot photo that gets beam back that could be doesn't even have to be more than 100 pixels by 100 pixels that even that would be a completely game-changing capability to be able to truly image these objects and um maybe at home in our own

solar system we can certainly get to a point where we produce crude maps of exoplanets um one of the kind of the ultimate limit of what a telescope could do is governed by its size and so the largest telescope you could probably ever build would be one that was the size of the sun there's a clever trick for doing this without physically building a TK that's the size of the sun and that's to use the Sun as a gravitational lens This was um proposed I think by vanan in like 1979 but it builds upon Einstein's

theory of general relativity of course that there is a warping of light a bending of light from the sun's gravitational field and so distant staright it's like a magnifying glass anything that bends light is is basically can be used as a telescope it's going to bend light to a point now it turns out the Sun's gravity is not strong enough to create a you know particularly great telescope here because the focus point is really out in the Kyper belt it's at 550 astronomical units away from the earth so 550 times further away from the Sun

than we are and we've you know that's beyond any of our spacecraft we've ever gone so you have to send a spacecraft to that distance which would take 30 40 years even optimistically improving our chemical propulsion system significantly you'd have to bound it into that orbit but then you could use the entire Sun as your telescope and with that kind of capability you could image planets to um kilometer scale resolution from afar and that that really makes you wonder I mean if we can conceive maybe we can't engineer it but if we can conceive of

such a device what might other civilizations be currently observing about our own planet um and perhaps that is uh why nobody is is visiting us because there is so much you can do from afar that to them that's enough they you know maybe they can get to the point where they can set our radio leakage um they can set our terrestrial in you know television signals um they can map out our surfaces they can tell we have cities they can even do infrared mapping of the heat island effect and all this kind of stuff they

can tell the chemical composition of our planet and so that might be enough maybe they don't need to come down to the surface and study anthrop in it do anthropology and see what our civilization is like um but there's certainly a huge amount you can do which is significantly cheaper to some degree than flying there just by exploiting cleverly the physics of the universe itself so your intuition is that's very very well may be true that observation might be way easier than travel from a from our perspective from an alien perspective like we could get

very high resolution imaging before we can ever get there it depends on what what information you want if you want um to know the chemical composition um and and you want to know kilometer scale maps of the planet then you could do that from afar with some uh version of these kind of gravitational lenses if you want to do better than that if you want to image uh a newspaper set on the porch of somebody's house you're have to fly there there's no way unless you had you know A tes that size of Sagittarius AAR

or something you just simply cannot collect enough light to do that from many light years away um so there is certainly uh reasons why visiting will always have its place depending on what kind of information you want um we proposed in my team actually that the sun is is a is the ultimate Pinnacle of telescope design MH but flying to a th Au is a real pain in the butt because it's just going to take so long and so a more practical way of achieving this might be to use the earth now the Earth doesn't

have anywhere near enough gravity to create a substantial gravitational lens um but it has an atmosphere and an atmosphere refracts light it bends light so whenever you see a sunset um just as the sun setting below the Horizon it's actually already Beneath The Horizon it's just the light is bending through the atmosphere it's actually already about half a degree down beneath and what you're seeing is is that is that curvature of the light path um and your brain interprets of course to be following a straight line because your brain always thinks that um and so

you can use that bending whenever you have bending you have a telescope and so we've proposed my team that you could use this refraction to similar create an earth siiz telescope called the terrascope the terrascope we have a great video on this yeah and uh this do you have a paper on the telescope I do yeah great um sometimes get confused this cuz they've heard of an earth-sized telescope cuz of they may have heard of The Event Horizon telescope which took an image of um what's taken an image right now of the center of our

black hole and it's very impressive and it previously did Messi 87 and nearby super massive black hole and so those images were interferometric so they were small telescopes scattered across the Earth and they combined the light paths together interferometrically to create effectively an earth-sized um angular resolution telescopes always have two properties there's the angular resolution which is how small of a thing you can see on the surface and there's the magnification how much brighter does that object get versus just your eye or some small object now what what the Event Horizon telescript did it traded

off um amplification or magnification for for the angular resolution that's what it wanted it wanted that high angular resolution but it doesn't really have much Photon collecting power because each telescope individually is very small the telescope is different because it is literally collecting light with a with a light bucket which is essentially the size of the Earth and so that gives you both benefits potentially not only the high angular resolution that a large aperture promises you but also actually physically collects all those photons so you can detect light from very very far away through outer

edges of the Universe um and so we yeah we propose this as a possible future uh technological way of achieving these these extreme goals ambitious goals we have in astronomy but um it's a very difficult system to test because you essentially have to fly out to these Focus points and these Focus points lie beyond the moon so you have to have someone who is willing to fly beyond the moon and hitchhike an experimental telescope onto it and do that cheaply if it was something doing low earth orbit it'd be easy you could just attach a

cube that to the next Falcon 9 rocket or something and test it out probably only cost you a few tens of thousands of dollars maybe hundred thousand dollars but there's basically no one who flies out that far except for uh bespoke missions such as like a mission that's going to Mars or something that would that would pass through that kind of space and they typically don't have a lot of leeway in excess payload that they willing to strap on for radical experiments so that's been the problem with it in theory it should work beautifully but

it's a very difficult idea to experimentally test can you elaborate why the focal point is that far away so you get about half a degree Bend from the Earth's atmosphere um when you're looking at the Sun at the Horizon and you get that two times over if you're outside of the planet's atmosphere because it comes you know the star is half a Bend to use on the horizon then half a degree back out the other way so you get about a one degree Bend you take the radius of the Earth which about 7,000 km and

do your arctan function you lend up with a distance that's about two it's actually the the inner focal point is about 2/3 the distance of the Earth Moon system the problem with that inner focal point is not useful because that light Ray path had to basically scrape the surface of the Earth so it passes through the clouds it passes through all the thick atmosphere it gets a lot of Extinction along the way if you go higher up in altitude you get less Extinction in fact you can even go above the clouds and so that's even

better because the clouds obviously are going to be a pain in the neck for doing anything Optical um but the problem with that is that the atmosphere because it gets thinner at higher altitude it bends light less and so that pushes the focal point out so the most useful focal point is actually about three or four times the distance of the Earth Moon separation and so that's what we call one of the LR points essentially out there and so there there was a stable orbit it's kind of the outermost stable orbit you could have around

the earth um so the atmosphere uh does bad things to to the signal yeah it's it's absorbing light um is that possible to to reconstruct this the to to to remove the noise whatever so it's just strength it's not nothing else it's possible to reconstruct I mean to some degree we do this as's a technology called Adaptive Optics that can correct for what's called wavefront errors that happen through the Earth's atmosphere the Earth's atmosphere is turbulent it is not a single plane of air of the same density there's all kind of Wiggles and currents in

the air and so that each little layer is uh bending light in in slightly different ways and so the light actually kind of follows a wiggly path on its way down what that means is that um two light rays which are traveling at slightly different spatial separations from each other will arrive at the detector at different times uh because one maybe goes on more or less a straight path and the other one Wiggles down a bit more before it arrives and so you have an incoherent um light source um and when you're trying to do

image Rec construction you always want a coherent light source so the way they correct for this is that this if this path had to travel a little bit faster uh straight one goes faster and the wiggly one takes longer the mirror is deformable and so you actually bend the mirror on this on the on the straight one down a little bit to make it an equivalent light path distance so the mirror itself has all these little actuators and it's actually made up of like thousands of little elements almost looks like a liquid mirror because they

can manipulate it in kind of real time and so they scan the atmosphere with a laser beam to tell what the defamations are in the atmosphere and then make the corrections to the mirror to account for it that's amazing so you could you could do something like this for the Terrace grrip but it would be um it's cheaper and easier to go above the atmosphere and just fly out I think so it would be very it's a very that's a very challenging thing to do and normally when you do Adaptive Optics as it's called you're

looking straight up so you're or we're very close to straight up if you look at the Horizon we basically never do astronomical observations on the horizon because you're looking through more atmosphere the if you go straight up you're looking at the thinnest portion of atmosphere possible but as you go closer and closer towards the horizon you're increasing what we call the air mass the amount of air you have to travel through so here it's kind of the worst case cuz you're going through the entire atmosphere in and out again with a terrascope so you'd need

a very impressive adaptive optic system to crit for that so yeah I would say it's probably simpler at least for proof of principle just to test it with um with with with having some satellite that was much wider orbit now speaking of traveling out into deep space yeah you already mentioned this a little bit uh you uh made a beautiful video called The Journey to the End of the Universe and sort of at the start of that you're talking about Alice andari so what would it take for humans or for human-like creatures to travel out

to Alpha centuri there's a few different ways of doing it I suppose um one is it depends on how fast your ship is that's always going to be the determining Factor if we devised some indide proportion system that could travel a fraction of the speed of light then we could do it in our lifetimes which is I think what people normally dream of when they think about inter you know propulsion and travel that you could literally step onto the spacecraft maybe a few years later you step off and Al centur B you walk around the

surface and come back and visit your family there would be of course a lot of relativistic time dilation as a result of that trip you would have aged a lot less than people back on Earth by traveling close to the speed of light for some fraction of time um the challenge of this of course is that we have no such propulsion system that can achieve this so but you think it's it's possible like uh so uh you have a paper called the Halo drive fuel free relativistic propulsion of large masses via recycled Boomerang photons so

uh do you think uh first of all what is that and and second of all uh how difficult are alternate propulsion systems yeah so the before I took the Halo drive there was there was an idea because I think the Halo drive is not going to solve this problem I'll talk about the Halo drive in a moment but the Halo drive is is useful for a civilization which is a bit more advanced than us that has spread across the stars and is looking for a cheap highway system to to get across the Galaxy for that

first step um because just to context that the the Halo drive requires black hoal so that's why you're not going to be able to do this on the Earth right now um but there are lots of black holes in the Milky wayte that's the good news so we'll come to that in a moment but if you're trying to travel to AF sentu without a black hole um then the the most you know there were some ideas out there there was a project dellis and project Icarus that were two projects at the um British interplanetary Society

conjured up on sort of a 20 30 year time scale and they asked themselves if we took existing and speculatively uh but realistic attempts at Future technology that are emerging over the next few decades how far could we P into uh travel system and they settled on uh Fusion drives in in that so if we had the ability to essentially U either detonate you can also Imagine That kind of nuclear fishion or nuclear fusion bombs going off behind the spacecraft and propelling it that way or having some kind of uh successful nuclear fusion reaction um

which obiously we haven't really demonstrated yet as a propulsion system then you could achieve something like 10% the speed of light in those systems but these are huge spacecrafts and I think you need a huge spacecraft if you're going to take people along um the conversation recently is actually switched and that's that idea is kind of seems a little bit Antiquated now and most of us have kind of given up in the idea of people physically biologically stepping on board the spacecraft and maybe we'll be sending something that's more like a micro probe that maybe

just weighs a a gram or two and that's much easier to accelerate you could push that with a laser system to very high speed get it to maybe 20% of the speed of light it has to survive the journey probably a large fraction of them won't survive the journey but they're cheap enough that you could maybe manufacture millions of them and some of them do arrive and able to send back an image or maybe even uh if you wanted to have a person there we might have some way of doing like a telepresence or some

kind of delayed telepresence or um some kind of reconstruction of the planet which is sent back so you can digitally interact with that environment in a way which is um not real time but representative of what that planet would be like to be on the surface so we might be more like digital visitors to these planets certainly far easier practically to do that than physically forcing this wet chunk of meat to Fly Light across space to do that um and so that's maybe uh something we can imagine down the road the Halo drive as I

said is is thinking even further ahead and if you did want to launch large masses large masses could even be Planet siiz things in the case of the Halo drive you can use black holes so this is kind of um a trick of physics you know I often think of the universe as like a big computer game and you're trying to find cheat codes hacks exploits that the Universe didn't intend for you to use but once you find them you can address all sorts of interesting capabilities that you didn't previously have yeah and um the

Halo drive does that with black holes so if you have two black holes which are very common situation a binary black hole um and they're inspiraling towards each other ligos detected I think dozens of these things maybe even over a 100 at this point and these things as they merge together they uh the Prem merger phase they're they're orbiting each other very very fast even close to the speed of light and so Freeman Dyson uh before he passed away I think in the' 70s he had this provocative paper called gravitational machines and he suggested that

you could use Neutron stars as a Interstellar propulsion system and neutron stars are sort of the uh the you know the lower Mass version of a binary black hole system essentially in this case he suggested just doing gravitational slingshot just fly your spacecraft into this uh very Compact and relativistic binary system and you do need neutron stars because if there were two stars they'd be physically touching each other so the neutron stars are so small that like 10 km across they can get really close to each other and have these very very fast orbits with

respect to each other you shoot your spacecraft through right through the middle like right through the eye of a needle and you do a slingshot around one of them and you do it around the one that's coming sort of towards you so one them be coming away one will be coming towards you any one point and then you could basically steal some of the kinetic energy in the slingshot in principle you can s up to twice the uh speed you can take your speed and it becomes your speed plus twice the the speed of the

black of the neutron star in this case and that would be your new speed after the slingshot this seems great because it's just free energy basically you're not doing any you know you're not generate you have a nuclear power react or anything to generate this you're just stealing it um and indeed you can get to relative stick speeds this way so I loved that paper but I had a criticism and the criticism was that this is like trying to fly your ship into a blender right this is this is two neutron stars which have huge

tital forces um and they're whipping around each other once every second or even less than a second and you're trying to fly your spaceship and do this maneuver that is pretty precarious and so it just didn't seem practical to me to do this but I loved it and so I I I took that idea and this is how science is it's iterative it's it's you take a previous great man's idea and you just sort of maybe slightly tweak it and prove it that's how I see the Halo drive and I just suggested why not replace

those out for black holes which is certainly very common and rather than flying your ship into that uh that hell hole of a blender System you just stand back and you fire a laser beam now because black holes have such intense gravitational fields they can bend light into complete 180s they can actually become mirrors so you know the sun bends light by maybe a fraction of a degree um through gravitational lensing but you know a compact object like a black hole can do a full 18 180 in fact if you obviously if you if you

went too close if you put the laser beam too close the black hole would just fall into it and never come back back out so you just kind of push it out push it out push it out until you get to a point where it's just skirting The Event Horizon and then that laser beam skirts around and it comes back now the laser beam wants to do a gra I mean it is doing a gravitational slingshot but laser I mean light photons can't speed up and like in like the spaceship case so instead of speeding

up the way they steal energy is they they increase their frequency so they become higher energy Photon packets essentially they get blue shifted so that you send maybe a red laser beam that comes back blue it's got more energy in it and because um photons carry momentum which is somewhat unintuitive in everyday experience but they do that's how solar cells work they carry momentum they push things um you can even use them as laser tweezers and things to pick things up um because they push the me it comes back with more momentum than it left

so you get an acceleration force from this and again you're just sealing energy from the black hole to do this so you can get up to the same speed it's basically the same idea as Freeman Dyson but doing it from a safer distance and there should be a order of you know a million or so or 10 million black holes in the Milky Way galaxy um some of them would be even as close as sort of 10 to 20 light years when you do the occurrence rate statistics of how close you might expect feasibly one

to be they're of course difficult to detect because they're black and so they're inherently hard to see but statistically there should be plenty out there in the Milky Way and so these objects would be natural Waypoint station you could use them to both accelerate away and to break and slow down and on top of all this you know there's we've been talking about astronomy and cosmology there's been a lot of exciting breakthroughs in in detection and exploration of uh black holes so the the the boomerang F boomeranging photons that you're talking about there been a

lot of work on photon rings and just all the fun stuff going on outside the black hole yeah um so all the the garbage outside is actually might be the thing that holds a key to understanding what's going on inside and there's the Hawking radiation there's all kinds of fascinating stuff like uh I mean there there's trippy stuff about black holes that I can't even well most people don't understand I mean the holographic principle with the plate and the information being stored potentially outside of the black hole I don't even I can't even comprehend how

you can project a three dimensional object on 2D and somehow store information where it doesn't destroy it and if it does destroy it uh challenging all the physics all all of this is very uh interesting especially for kind of more practical applications of how the black hole can be used for propulsion yeah I mean it may be that black CS are used in all sorts of ways um by Advanced civilizations I think uh again it's been a popular idea in science fiction or science fiction Trope that Sagittarius AAR the super massive black Cole and the

centr Galaxy could be the best place to look for intelligent life in the universe because it is a giant uh engine in away you know a unique capability of a black hole is you can basically throw matter into it and you can get these jets that come out the incretion discs and the jets that fly out and so you can more or less use them to convert matter into energy V equal mc² and there's pretty much nothing else um except for you know Annihilation with with its own antiparticle as a way of doing that so

they have some unique properties you could perhaps power a civilization by just throwing garbage into a black hole right just throwing asteroids in power your civilization with as much energy as you really would ever plausibly need and you could also use them to accelerate away Across the Universe and you can even imagine using small artificial black holes as thermal generators right so the Hawking radiation from them kind of exponentially increases as they get smaller and smaller in size and so um a very small black hole one you could almost imagine like holding in your hand

would be a fairly significant heat Source um and so that raises all sorts of prospects about how you might use that in an engineering context to power your civilization as well um you have a video on becoming a CF type one civilization what what's our hope for doing that or a few orders of magnitude away from that yeah it is surprising I think people tend to think that we're close to this this scale the the kardashev type one is is defined as a civilization which is using as much energy as is essentially incident upon the

planet from the Star um so that's of order I think for the Earth of something like 10 to the 5 teros or 10 the 7 teros is a it's a gigantic amount of energy and we're using a tiny tiny tiny fraction of that right now so um you know if you became a Kev type one civilization which is seen not necessarily is a goal into itself I think people think why why are we aspiring to become this energy hungry ization you know surely um our our energy needs might become you know might impr improve our

efficiency or something as time goes on but ultimately the more energy you have access to the greater your capabilities will be I mean if you want to lift Mount Everest into space there is just a calculable amount of potential energy change that that's going to take in order to accomplish that and the more energy you have access to as a civilization then clearly the easier that energy achievement is going to be so depends on what you're ask ation are as a civilization it might not be something we want to ever do but well but we

should make clear that lifting heavy things isn't the only thing it's uh it's just doing work so it could be computation it could be it could be more and more and more and more sophisticated and larger and larger and larger computation which is it does seem where we're headed with a uh ve very fast increase in um the the scale and the quality of our computation outside the human brain artificial comp competition yeah I mean competition is a great example of I mean already I think something like 10% of us power electricity use is going

towards the supercomputing centers so there's a there's a vast amount of uh current engine needs which are already going towards Computing we surely only increase over time um if we start ever doing anything like mind uploading or creating simulated realities that that cost will surely become almost a dominant source of our energy requirements at that point if civilization completely moves over to this kind of post-humanism stage and so it's not unreasonable that our energy needs would continue to grow certainly historically they always have at about 2% per year and so if that continues there is

going to be a certain point um where you're running up against the amount of energy which you can Harvest because it's you're using every even if you cover the entire planet in solar panels um there's no more energy to be had um and so this is a you know there's a few ways of achieving this I sort of talked about in the video how there were several renewable energy sources that we're excited about like geothermal wind power waves but pretty much all of those don't really scratch the surface or don't really scratch the itch of

getting into a kardashev type one civilization they're meaningful now I would never tell anybody don't do wind power now because it's it's it's clearly useful our current stage of a civilization but it's not it's going to be a pretty negligible fraction of our energy requirements if we got to that stage of development and so there has to be a breakthrough in either I ability ility to harvest solar energy which would require maybe something like a space array of solar panels of beaming the energy back down or some developments uh and Innovations in in nuclear fusion

that would allow us to essentially reproduce the same process of what's producing in the Solar photons but here on Earth um but even that comes with some consequences if you're generating the energy here on Earth and you're doing work on it on Earth then that work is going to produce waste heat and that waste heat is going to increase the ambient temperature of the planet and so you whether even if this isn't really a greenhouse effect that you're increasing the temperature of the planet this is just the amount of computers that are churning you put

your hand to a computer you can feel the warmth coming off them if you do that much work of literally you know the entire instant energy of the planet is doing that work uh the planet is going to warm up significantly as a result of that and so you know that's uh it that clearly indicates that this is not a sustainable path that civilizations as they approach Kev type one are going to have to leave planet Earth which is really the point of that video to show that it's a Kev type one civilization even though

it's defined as instant energy upon a planet that is not a species that is going to still be living on their Planet at least um in isolation they will have to be harvesting energy from afar they will have to be you doing work on that energy outside of their Planet because otherwise you're going to dramatically change the environment in which you live well yeah so the it's uh the more energy you create the more energy you use the more the higher the imperative to expand out into the universe but also not just the imperative but

the uh the capabilities and you're you've kind of as a side on your lab page mentioned that you're sometimes interested in astroengineering uh so what what kind of uh space architectures do you think we can build to house humans or interesting things outside of Earth yeah I I mean there's there's a lot of fun ideas here um one of the classic ideas is an oal cylinder or a Stanford Taurus these are like two rotating structures that were devised in space that're basically using the centrifugal force as artificial gravity um and so these are structures which

tend to be many kilometers across that you're building in space but could potentially habitat um millions of people in in orbit of the earth um of course you could imagine pulling them if you you know the expanse does a pretty good job I think of exploring the idea of human exploration of the solar system and having uh many objects many of the small near Earth objects and asteroids inhabited by mining colonies um one of the ideas we've played around with our group is this technology called aqu quazite aqu quazite is um an extension again we

always tend to extend previous ideas ideas built upon ideas but an extension of idea called a statite a datte was an idea proposed I think by Ron forward in the 1970s 1970s seemed to have all sorts of wacky ideas don't know what was going on then we the I think the Stanford Taurus the O'Neal cylinder statites um the the gravitational lens people were really having fun with dreaming about space in the 70s uh the statti is is basically a a solar sale but it's such an efficient solar sale that the outward force of radiation pressure

equals the inward Force force of gravity from the Sun mhm and so it doesn't need to orbit normally you avoid the sun is pulling us right now through force of gravity but we are not we are not getting closer towards the sun even though we are Falling Towards the sun because we're in orbit which means our translational speed is just enough to keep us at the same altitude essentially from the Sun and so you're in orbit and that's how you maintain distance a statite doesn't need to do that it could be basically you know completely

static in inertial space but it's just balancing the two forces of radiation pressure and inward gravitational pressure a quazite is the in between of those two states so it's it has some significant outward pressure but not enough to resist fully falling into the star and so it compensates for that by having some translational motion so it's in between an orbit and a statite and so what that allows you to do is maintain artificial orbits so normally you you know if you want to calculate your orbital speed of a of something that say say half an

au you would use kep's third law and go through that and you'd say okay you know if it's that half an au I can calculate the period by P squ as proportional to a cubed and go through that but for a um a quazite you can basically have any speed you want it's just a matter of how much uh how much of the gravitational force are you balancing out you effectively enter an orbit where you're making the mass of the star be less massive than it really is so it's as if you orbiting a 0.1

solar mass star or 0 2 solar mass star whatever you want and so that means that uh Mercury orbits with a pretty fast gravitation uh a pretty fast orbital speed around the sun because it's closer to the Sun than we are but we could put something in Mercury's orbit that would have a slower speed and so it would crack with the Earth and so we would always be aligned with them at all times and so this could be useful if you wanted to have a um either a chain of of colonies or something that we're

able to easily communicate and trans and uh and move between one another between these different bases You' probably use something like this to maintain that uh easy transferability or you could even use it as a uh a space weather monitoring system which actually proposed in the paper we know that uh major events like the Caron event that happened you know can knock out all of our electromagnetic systems quite easily a major solar flare could do that a g magnetic storm but if we had the ability to detect those uh higher elevated activity Cycles in advance

um the problem is they travel obviously pretty fast and so it's hard to get ahead of them but you could have a station which is basically sampling solar flares very close to the surface of the Earth and as soon as it detects anything suspicious um magnetically it could then send that information straight back at the speed light to your Earth and give you maybe uh half an hour warning or something that something you know something bad was coming you should shut off all your uh systems or get in your Faraday cage now and protect yourself

um and so these These quites are kind of a cool trick of again kind of hacking the laws of physics it's like another one of these exploits that the Universe seems to allow us to do to potentially manifest um these artificial systems that would otherwise be difficult to to produce so leveraging natural phenomena yeah that's always the key is is to work in my mind is to work with nature that's how I see astroengineering right rather than against it you're not trying to force it to do something you know it that's why you always think

solar energy is so powerful because um in the battle against nuclear fusion nuclear fusion you're really fighting a battle where you're trying to confine plasma into this extremely tight space or um it's the sun does this for free it has gravitation and so that's the that's in essence what a solar panel does it it's exp it is a nuclear fusion reactor fueled Energy System but it's just using gravitation for the confinement and having a a Hu a huge standoff distance for it energy collection and so um there are tricks like that it's very naive simple

trick in that case where we can rather than having to reinvent the wheel we can use the space infrastructure if you like the astrophysical infrastructure that's already there to our benefit yeah I think in the long Arc of human history probably natural phenomena is the right Solution that's the simple that's the elegant solution CU all the power is already there that's why a d sphere in the long sort of but you don't know what a d sphere would look like but some kind of thing that leverages the power the energy that's already in the sun

is is better than uh creating artificial nuclear uh fusion reaction but then again that brings us to a topic of AI how much of this if we're traveling out there inter St of travel or um doing some of the interesting things we'll been talking about how much of those ships would be occupied by AI systems do you think what would the what would be the living organisms occupying those ships yeah it it's depressing to think about AI in the search for life because it had I mean I've been thinking about this a lot over the

last few weeks with playing around with chat gbt 3 like many of us and being astonished with its capabilities and you see that it that our society is undergoing a change that seems significant in terms of the development of artificial intelligence we've been promised this revolution this Singularity for a long time but it really seems to be stepping up its uh its pace of development at this point and so that's interesting because as someone who looks for alen life out there in the universe um it sort of implies that our current stage of development is

highly transitional and that you know you go back for the last four and a half billion years the planet was dumb essentially if you go back uh last few thousand years there was a civilization but it wasn't really producing any Techo signatures and then over the last maybe hundred years there's been something that might be detectable from afar but we're potent approaching this curp where we might imagine it I mean we we thinking of like maybe years and decades with AI development typically when we talk about this but as an astronomer I have to think

about much longer time scares of centuries Millennia millions of years and so if this if this wave continues over that time scale which is still the blink of an eye on a cosmic time scale that implies that everything will be AI essentially out there if this is a common behavior and so that's intriguing because it sort of implies that we are uh special in in terms of Our Moment In Time as a civilization which it normally is um something we're averse to as astronomers we we normally like this mediocrity principle we're not special we're a

typical part of the universe some the cosmological principle but in a temporal sense we may be in a unique location and perhaps that is part of the a solution to the firmy Paradox in fact that if it is true that planets tend to go through basically three phases is dumb life for the vast majority a a brief period of biological intelligence and then an extended period of artificial int intelligence that they transition to then we would be in a unique and special moment in Galactic history that would be of particular interest for any Anthropologist out

there in the galaxy right this would be the time that you would want to study civiliz a civilization very carefully you wouldn't want to interfere with it you would just want to see how it plays out kind of similar to the ancestor simulations so sometimes start up with the simulation argument that you are able to observe perhaps your own Origins and study how the transformation happens and so yeah that has for me recently been throwing the fing Paradox a bit on its head and this idea of the the zoo hypothesis that we may be monitored

which has for a long time been sort of seen as a fringe idea even amongst the seti community but if we live in this truly transitional period it it adds a lot of impetus to that idea I think well even AI itself would by its very nature would be observing Us by you know it's like uh human there used to be this concept of human computation which is actually exactly what's feeding the current chat uh language models which is leveraging all the busy stuff we're doing to do the hard work of learning so like uh

the language models are trained on human interaction in human language on the internet and so it would AI feeds on the output of brain power from humans MH and so like it would be observing and observing and it gets stronger as it observe so it actually gets extremely good at observing humans and one of the interesting philosophical questions that starts percolating is what makes us what is the interesting thing that makes us human we tend to think of it uh and you said like there's three phases what's the thing that's hard to come by in

phase three is it something like scarcity which is limited resources is it something like Consciousness is that the thing that's very what um that emerged The evolutionary process in biological systems that are operating under constrained resources this thing that feels that it feels like something to experience the world which we think of as Consciousness is that really difficult to replicate is in in artificial systems is that the thing that makes it fundamentally human or is it just a side effect uh that we attribute way too much importance to do you do you have do you

have a sense if you look out into the future and AI systems are the ones that are traveling out there to Alpha centory and Beyond do you think they have to carry the the flame of Consciousness with them no not necessarily um they they may do but they may it may not be and necessarily I mean there I guess we're talking about the difference here between sort of an AGI artificial general intelligence or Consciousness which are distinct ideas and you can certainly have one without the other so I could imagine I would I would disagree

with this certainly in that statement okay okay I I I think it's very possible in order to have intelligence you have to have consciousness okay well I mean to to a certain degree chat gbt 3 has a level of intelligence already it's not a general intelligence but it it displays properties of intelligence with with no consciousness so again I would disagree okay okay well I I don't I don't I don't know I because you said it's very nicely you said it displays properties of intelligence in the same way it displays properties of intelligence I would

say it's starting to display prop properties of Consciousness it certainly could fool you that it's conscious correct yes there I guess like a a cheing test problem like if it's displaying all those properties if it if it quacks like a parrot looks like a parrot or quacks like a duck things like isn't it isn't it basically a duck at that point so yeah I can I can see that argument um it probably it I mean certainly as I tried to think about it from the observer's point of view as an astronomer what am I looking

for whether that intelligence is conscious or not has little bearing I think as to what I should be looking for when I'm trying to detect evidence of them it would maybe affect their behavior in ways that I can't predict um but that's again getting into the game of what I would call xenos psychology of trying to make projections about the motivations of an alien species is incredibly difficult and similar for any kind of artificial intelligence it's unfathomable what it intentions may be I mean I would sort of question whether it would even be interested in

traveling between the stars at all if its primary goal is computation computation for the sake of computation then it's probably going to have a different way of you know it's going to be engineering its Soler system and the nearby material around it for for a different goal if it's just simply trying to increase computer substrate Across the Universe and that of course if that is its principal intention to just essentially convert dumb matter into smart matter as it goes then I think that would come into conflict with our observations of the universe right because the

the Earth shouldn't be here if that were true the Earth should have been transformed into computer substrate by this point there has been plenty of time yeah in the history of the Galaxy for that to have happened um so I'm skeptical that we can uh I'm skeptical in the part that that that's a behavior that AI or or any civilization really engages in but I also find it difficult to find a way out of it to to explain why that would never happen in the entire history of the Galaxy amongst potentially if life is common

Millions maybe even billions of instant instantiations of AI could have occurred across the Galaxy um and so that seems to be a knock against the idea that there is life else or intelligent life elsewhere in the in the Galaxy the fact that that hasn't occurred in our history is maybe the only solid data point we really have about the activities of other civilizations of course the scary one could be that um we just at this stage intelligent alien civilizations just start destroying themselves it just it becomes too powerful everything's just too many weapons too many

nuclear weapons too many nuclear weapon style systems that just from mistake to aggression to like the probability of self-destruction is too high relative to the challenge of of avoiding the technological challenges of avoiding self-destruction you mean the the AI destroys itself or we destroy prior to the Advent of AI as we get smarter and smarter AI um either AI destroys us or other there could be just a million like AI is correlated the development of AI is correlated with all this other te technological innovation uh genetic genetic engineering like all kinds of engineering at the

Nano scale Mass manufacturer of things that could destroy us or cracking physics enough to have very powerful weapons nuclear weapons all of it just too much physics enables way too many things that can destroy us before it enables the um the propulsion systems that allow us to fly far enough away before we destroy ourselves so maybe that's what happens to the other alien civilizations is that your resolution because I I mean I think us in the techos signature community and theic Community aren't thinking about this problem seriously enough in my opinion we should we should

be thinking about the what AI is is is doing to our society and the implications what we're looking for and so the only I think part of this thinking has to involve people like yourself who are more intimate with the machine learning and artificial intelligence world is your how do you reconcile in your mind you said earlier that you think you can't imagine a Galaxy where life and intelligence is not all over the place and if artificial intelligence is a natural progression for civilizations how do you reconcile that with with the absence of any information

around us or any clues or hints of artificial Behavior artificially engineered stars or colonization computer substrate transformed planets anything like that it's it's uh extremely difficult for me it's the the firmy Paradox broadly defined is extremely difficult for me and the the terrifying thing is one thing I suspect is that we keep destroying ourselves the probability of self-destruction with with advanced technology is just extremely high that's why we're not seeing it m but then again my intuition bu about why we haven't blown ourselves up with nuclear weapons it it's very surprising to me from a

scientific perspective yeah it doesn't given all the cruelty I've seen in the world um given the the the power that nuclear weapons placed in the hands of very small number of individuals it's very surprising to me we destroy ourselves and it seems to be a very low probability situation we have happening here um but and then the other explanation is the is the zoo is the observation that we're just being observed that's the that's the only other thing it's just it's so difficult for me um of course all of science everything is very humbling it

would be very humbling for me to learn that we're alone in the universe it would change you know what it maybe I do want that to be true because you want us to be special that's why I'm resisting that thought maybe there's no way we're that special there's no way we're that special that's that's that's where my resistance comes from I I would just say you know the specialness is something we we in implicitly in that statement there's kind of an assumption that we are something positive like we're a gift to this planet or something

and that makes it special but you know it may be that intelligence is more of is like we're like rats or cockroaches we're an infestation of this planet we're not we're not some benevolent property that the planet would Planet would ideally like to have if you can even say such a thing but we we may be not only a generally a negative Force for a planet's biosphere and its own survivability which I think you can make a strong argument about but we may also be a very persistent infestation that may even in you know interesting

thoughts there in the wake of a nuclear war would there be an absolute eradication of every human being which would be a fairly extreme event or would the candle of Consciousness as you might call it the flame of Consciousness continue with some small Pockets that would maybe in 10,000 years 100,000 years we' see civilization reemerge and play out the same thing over again yeah that's certainly but nuclear weapons aren't powerful enough yet but yes the uh but to sort of push back on the infestation sure but the word special doesn't have to be positive I

just mean I think it tends to imply but I take your point yeah but maybe um just maybe extremely rare might be yeah and that to me it just it's it's very strange for me to be cosmically unique it's just very strange I I I mean that we're the only thing of this level of complexity in the Galaxy just seems very strange to me I I would just yeah I as said I do think it depends on this classific ation I think there is sort of again it's kind of buried within there as a subtext

but there is a a classification that we're doing here that what we are is a distinct category of of life let's say in this case when we're talking about intelligence we are something that can be separated um but of course we see intelligence across the Animal Kingdom in you know dolphins hbat whales um octopuses crows Ravens and so it's quite possible that um that these are all manifestations of the same thing and we are not uh we are not a particularly distinct class except for the fact we make technology that's really any difference to our

intelligence and we we classify that separately but from a biological perspective to some degree it's really just all part of a Continuum and so that's why I when we talk about unique you're you you are P putting yourself in a box which is distinct and saying this is the only example of things that fall into this box but the but the walls of that box May themselves be a construct of our own arrogance that we are something distinct yeah and uh but I was also speaking broadly for us meaning all life on Earth that but

then it's possible that there's all kinds of living uh ecosystems in on other planets and other moons that just don't have interest in technological development mhm and may maybe May technological development is the the the parasitic thing it destroys the organism broadly and then maybe that's actually one of the fundamental realities whatever broad way to categorize technological development that's that's just a parasitic thing that just destroys itself it's a cancer you know we're flirting around sorry to interrupt we're flirting around this idea of the great filter a little bit here so we be asking where

is this does it lie ahead of us nuclear war maybe imminent that would be a filter that ahead of us or could it be behind us and that it's the Advent of technology that is genuinely a rare occurrence in the universe and that explains the FY Paradox um and so that's uh that's something that obviously people have debated and gone argued about in set for decades and decades but it remains a a persistent people argue whether it should be really called a paradox or not but it remains a consistent apparent contradiction that you can make

a very Cent argument as to why you expect life and intelligence to be common in the universe and yet everything everything we know about the universe is fully compatible with just us being here and that's a haunting thought but um I'm not I have no preference or desire for that to be true I'm not trying to impose that view on anyone but I do ask that we remain open-minded until evidence has been collected either way well the thing is it's one of if not the probably I would argue it's the most important question facing human

civilization or the most interesting yeah I I think scientifically speaking like what question is more important than um they somehow you know there could be other ways to sneak up to it but it gets to the essence of what we are what these living organisms are is somehow seeing Another Kind yeah helps us understand it speaks to The Human Condition helps us understand what it is to be human to some degree um I think you know I I have tried to mean remain very agnostic about the idea of life and intelligence one thing I try

to be more optimistic about and I've been thinking a lot with our searches for life in the universe is life in the past you can I think it's actually not that hard to imagine we are the only civilization in the galaxy right now living yeah that's that's currently extent but there may be very many extinct civilizations if each civilization has a typical lifetime comparable to let's say AI is the demise of our own that's only a few hundred years of technological development or maybe 10,000 years if you get back to the ne ethic re Revolution

the dawn of Agriculture you know hardly anything in Cosmic time span um that that's nothing that's the blink of an eye and so it's not surprising at all that we would happen not to coexist with anyone else but that doesn't mean nobody else was ever here and if other civilizations come to that same conclusion and realization maybe they scour the Galaxy around them don't find any evidence for intelligence then they have two options they can either give up on communication and just say well it's never going to happen uh we just may as well just

you know worry about what's Happening Here on our own planet or they could attempt communication but communication through time mhm and that's that's almost um the most selfless Act of communication CU there's no hope of getting anything back it's um a philanthropic gift almost to that other civilization that you can maybe maybe might just be nothing more than a monument which the pyramids essentially are a monument of their existence that these are the things they achieved this is their you know the things they believed in their language their culture or um it could be maybe

something more than that it could be sort of lessons from what they learned and their own history and so I've been thinking a lot recently about how would we send a message to other civilizations in the future because that act of thinking seriously about the engineering of how your designer would inform us about what we should be looking for and also perhaps be our best chance quite frankly of ever making contact it might not be the contact we dream of but it's still contact they would there would still be a record of our existence as

pitiful as it might be compared to a two-way communication and I love the humility behind that project that Universal project yeah it's uh sort of it's humble and the it uh humbles you to the the vast temporal landscape with the universe just realizing our like day-to-day lives they all of us will be forgotten mhm it's nice to think about something that sends a signal out to other um yeah it's it was almost like a humility of acceptance as well of like knowing that you have a terminal disease but your impact on the earth doesn't have

to end with your death and it could go on Beyond with what you leave behind for others to discover with maybe the books you write or what you leave in the literature do you think launching the Roadster vehicle out in the Roadster um I'm not sure what someone would make of that if they yeah that's true um I mean there have been quasi attempts at it beyond the Roadster I mean there's like plaques on there's the Pioneer plaques um there's the Voyager to Golden record um it's pretty unlikely anybody's going to discover those uh because

they're just a drift in space and they they they will eventually mechanically die and not produce any signal for anyone to spot so you'd have to be extremely lucky to come across them I've I've often said to my colleagues I think the best place is the Moon the Moon unlike the Earth has no significant weathering the you know the how long will the Apollo descent stages which are still s on the lunar surface last for the the only real effect is micrometeorites which are slowly like dust smashing against them pretty much um but that's going

to take Millions potentially billions of years to erode that down and so we have an opportunity and that's on the surface if you put something just a few meters beneath the surface it would have even greater protection and so it raises the prospec of that if we wanted to send something a significant amount of information to a future Galactic spanning Civilization that maybe cracks the intercell propulsion problem the moon's going to be there for five billion years that's a long time for somebody to come by and detect maybe a strange pattern that we draw on

the sand for them to you know big Arrow big cross like look into here and we could have a tomb of knowledge of some record of our civilization um and so I think it's uh when you think like that what that implies to us well okay the Galaxy's 13 billion years old the Moon is already 4 billion years old there may be places familiar to Us nearby to us that we should be seriously considering as places we should look for life and intelligent life or evidence of relics that they might leave behind for us so

that thinking like that will help us find such relics and it's like a it's a a it's like a beneficial cycle that happens yes yeah exactly that enables the science of of study better like of of searching for bi and Tech signatures and so on yeah and it's inspiring I mean it's it's it's it's it it's also inspiring in that we want to leave a legacy behind as an entire civilization not just in the symbols but broadly speaking yeah that's the last thing somehow yeah and I'm part of a team that's trying to re re

repeat the golden record experiment uh we're trying to create like an open source version of the golden record that future spacecraft are able to download and basically put a little hard drive that they can carry around with them and you know get these distributed hopefully across the solar system eventually and going to be called the hit hackers guy to the Galaxy or could be that's a good name for it we've we've been toying a little bit with name but I think probably just be golden record at this point or golden record version two or something

but um I think uh I think another benefit that I see of this activity is that it forces us as a species to ask those questions about what it is that we want another civilization to know about us the Goden record was kind of funny because it had photos on it and it had photos of people eating for instance um but had no photos of people defecating mhm and so I was thought that was kind of funny because if I was if I was an alien yeah or if I was studying an alien if I

saw images of an alien I would I'm not trying to be like a perver or anything but I would want to see the full bi I want understand the biology of that alien and so we we always censor what we what we show um and we we should show the whole actual natural process and then also say we humans tend to censor these things we tend to not like to walk around naked we tend to not to talk about uh some some of the natural biological phenomena and talk a lot about others yeah and and

actually just be very uh like the way you would be to a therapist or something very transparent about the way we actually operate this world I mean and Sean had the Sean had that with the golden record I think he he originally there's a there's a male and a female figure to pit on the golden record and the the woman had a genitalia originally drawn and uh there was a lot of push back from I think a lot of Christian groups who were not happy about the idea of throwing this into space And So eventually

they had to remove that and so it's it would be confusing biologically if you're you know trying to study xenobiology of of this alien that apparently has no genitalia or the man does but for some reason the woman doesn't you know and that's our that's our own uh societal and cultural um imprint happening into that information that's to be fair just even having two sexes and predators and prey just a whole that could be just a very unique earthlike thing so they might be confused about why there's like pairs of things like why are you

like why why is there a man and a woman in general like they they could be I mean they could be confused about a lot of things in general I don't I don't think the they don't even know which way to to hold the picture or they is the picture they don't they might not need they they might have very different sensory devices to even interpret this they only you know have uh sound as their only way of navigating the world it's kind of lost just to send any kind of there been a lot of

conversation about sending video and uh audio and uh video and pictures and I've that's one of the things I've been a little bit resistant about in the team that I've been thinking well they might have eyes and so if you lived in um under the Europa surface having eyes wouldn't be very useful um if you lived in a on a very dark planet on the tightly locked night side of an exoplanet having eyes wouldn't be particularly useful so it's kind of a presumption of us to think that video is a useful form of communication do

you hope we become a multiplanetary species so we almost sneaking up to that but um you know the efforts of SpaceX of Elon maybe in general what your thoughts are about those efforts so you already mentioned Starship will be very interesting for astronomy for for science in general just getting stuff out into space but what about the longer term goal of actually colonizing of building civilizations on other surfaces on moons on planets it seems like an a fairly obvious thing to do for our survival right there's a high risk if if we are committed to

trying to keep this human human experiment going um putting all of our eggs in one basket is always going to be a risky strategy to pursue it's a nice basket though but yeah it is a beautiful basket I wouldn't want to I personally have no interest in living on mars or the moon I would like to visit but I would definitely not want to spend the rest of my life and die on Mars it's a it mean it's a hell hole Mars is a very very diff I think the idea this is going to happen

in the next you know 10 20 years is seems to be very optimistic um not that it's in some mountable but the the challenges are extreme to survive on a planet like Mars which is you know like a dry Frozen desert um with a high radiation environment it's it it's a challenge of of a type never faced before so it's I'm sure human Ingenuity can tackle it but I'm skeptical that we'll have thousands of people living on Mars in my lifetime but I would I would relish that opportunity to maybe one day visit such a

settlement and you know um do scientific experiments on mars or experience Mars uh do astronomy from Mars you know all sorts of cool stuff you could do um you know sometimes you see these dreams of outter solar system exploration and you can like fly through the clouds of Venus or you could um just do these enormous jumps on like these small moons where you can essentially jump as high as a skyscraper and Traverse the mean so there's all sorts of you know Wonderful ice skating on Europa might be fun so d r i love the

idea of us becoming into planetry I think it's um it's just a question of uh time our own our own destructive Tendencies uh as you said earlier are add odds with our emerging capability to become interplanet Tre and the question is will we get out of the nest before we burn it down and I I don't know I obviously I hope that we do but I I don't have any special Insight that there there is a pro there is somewhat of a um an noring intellectual itch I have with the So-Cal doomsday argument which um

I try not to treat too seriously but there is some element of it that bothers me uh the Dooms argument basically suggests that you know you're typically the mediocrity principle you're not special that you're probably going to be born somewhere in the middle of all human beings who will ever be born you're unlikely to be one of the first 1% of human beings that ever lived and one of the last one and similarly the last 1% of human beings that will ever live because it'd be very unique and special if that were true and so

by this logic you can sort of calculate um how many generations of humans you might expect so if there's been let's say 100 billion human beings that have ever lived on this planet then you could say to 95% confidence so uh you divide by 5% so 100 billion divided by 005 would give you two trillion human beings that would ever live you'd expect by this argument and so if each um if let's say each each planet in general the planet has a 10 billion population so that would be 200 generations of humans we would expect

ahead of us and if each one has an average lifetime is 800 years then that would be about 20,000 years so there's 20,000 years left on the clock that's like a typical doomsday argument type uh that's how they typically lay it out um now you can AR the a lot of the criticisms that de so argument come down to what are you really counting you're counting humans there but maybe you should be counting years or maybe you should be counting human hours you know how what are you because what you count makes a big difference

to what you get out in the other end this is called the reference class um and so that's one of the big criticisms of the Doomsday argument but I do think it has a compelling point that it would be surprising if our future is to one day Blossom and become a Galactic spanning Empire trillions upon trillions upon trillions of human beings will one day live across the stars for essentially as long as the Galaxy exists and the Stars Burn we would live at an incredibly special point in that story we will be right at the

very very very beginning and that's not impossible but it's just somewhat improbable and so there's part of that sort of um irks against me but it also almost feels like a philosophical argument because you're sort of talking about souls being drawn from this Cosmic pool um so it's it's not an argument that I lose sleep about for our fate of the Doomsday but it is um somewhat intellectually annoying that that there is a a slight contradiction now it feels like with the idea of a Galactic spanning Empire and but of course there's so many unnes

I I for one would love to visit even space but Mars just imagine standing at Mars and looking back at Earth yeah I mean um the incredible site it would give you such a fresh perspective as to your entire existence and what it meant to be human yeah and then come back to Earth it would it would give you give you a heck of a perspective plus the the sunset on Mars is supposed to be nice I loved what William Shatner said after his flight um his words really moved me when he came down and

I think uh it it really captured the idea that we shouldn't really be sending uh Engineers our scientists into space we should be sending out poets because those are the people when they come down who can who can truly make a difference with when they describe their experiences in space and I found it very moving reading what he what he said yeah when you talk to astronauts when they when they describe what they see it's like this like they've discovered a whole new thing that they can't possibly convert back into words yeah um yeah it's

it's beautiful to see just as a quick before I forget I have to ask you um can you summarize your argument against the hypothesis that we live in a simulation is it Sim similar to our discussion about uh the Doomsday Clock um no it's actually probably more similar to my um agnosticism about life in the universe and it's just sort of remaining agnostic about all possibilities um the simulation argument sometimes it gets um it mixed there's kind of two distinct things that we need to consider one is the probability that we live in so-called Bas

reality that we're not living in a simulated reality itself and another probability we need to consider is the ility that that technology is viable possible and something we will ultimately choose to one day do those are two distinct things they're probably quite similar numbers to each other but they are distinct probabilities so my in my paper I I I wrote about this I just tried to work through the problem I teach Asos statistics actually teaching it this morning and so it just seemed like a fun case study of working through a basing calculation Fred um

Bas in calculations work on conditionals and so when you here you know what kind of inspired this project was when I heard musk said was like a a billion to one chance that we don't live in a simulation um he's right if you add the basing conditional and the basing conditional is as conditioned upon the fact that we eventually develop that technology and choose to use it or it's it's it's chosen to be used by such species by such civilizations that's the conditional and you have to add that in because that conditional isn't guaranteed and

so um in a basing framework you can kind of Make That explicit you see mathematically explicitly that's a conditional in your equation and the the opposite side of the coin is basically um in the trilemma that Bostrom originally put forward it's options one and two so option one is that you basically never develop the ability to do that option two is you never choose to execute that so we kind of group those together as sort of the uh the nonsimulation uh scenario let's call it so you've got non-simulation scenario simulation scenario and agnostically we really

have to give the you know how do you assess the model the a prior model probability of those two scenarios um it's very difficult and we can I think people would probably argue about how you assign those priors in the paper we just assigned 50/50 we just said we this hasn't been demonstrated yet there's no evidence that this um is actually technically possible but nor is it is not technically possible so we're just going to assign 50/50 problem to these two hypotheses and then in the hypothesis where you have a simulated reality you have a

base reality set at the top so there is even in the simulated hypothesis there's a probability you still live in Bas reality and then there's a whole Myriad of universes beneath that which are all simulated um and so you have a ve you have a very slim probability of being in base reality if this is true and you have a 100% probability of living in base reality on the other hand if it's not true and we never develop that ability or choose never to use it and so then you apply this technique called basy Model

averaging which is where you propagate the uncertainty of your two models to get out a final estimate and because of that one base reality that lives in the simulated scenario you end up counting this up and getting that it always has to be less than 50% so the probability Liv in in a simulated reality versus BAS reality has to be slightly less than 50% um now that really comes down to that statement of giving it 50/50 odds to begin with and on the one hand you might say look David I'm you know I work in

artificial I'm very confident that this is going to happen just of extrapolating of current trends or on the other hand a statistician would say um you're giving way too much uh weight to the simulation hypothesis because it's an intrinsically highly complicated model you have a whole hierarchy of realities within realities within realities it's like the Inception style thing right and so this requires hundreds thousands millions of parameterizations to describe and by aam's razor we would always normally penalize inherently complicated models as being disfavored so I think you could argue on being too generous or too

kind with that but I sort of want to develop the the rigorous mathematical tools to explore it and ultimately it's up to you to decide what you think that 50/50 odds should be but you can use my formula to plug in whatever you want and get the answer and I use 50/50 so and but when in that first pile uh with the first two parts parts of the the the that the bostom talks about it seems like connected to that is the question we've been talking about which is the number of times at bat you

get which is the number of intelligent civilizations there out there that can uh build such simulations that it seems like very closely connected cuz if we're the only ones that are here and can build such things that changes things yeah yeah I mean this yeah the simis has all sorts of applications like that um I've always love Sean car pointed out a really interesting contradiction apparently with the simulation hypothesis that I speak about a little bit in the paper but he showed that um or or pointed out that in this hierarchy of realities which then

develop their own AIS within the realities and then they or or really ancestor simulations I should say rather than AI they develop their own capability to simulate realities you get this hierarchy and So eventually there'll be a bottom layer um which I often call the Sue of reality is like the worst layer where it's the most pixelated it could possibly be right so cuz each layer is necessarily going to have less competitional power than the layer above it because not only are you simulating that entire planet but also some of that's being used for the

the computers themselves that those are simulated and so that base reality or sorry the B the Sue of reality is a is a is a reality where they are simply unable to produce ancestor simulations because the Fidelity of the simulation is not sufficient and so from their point of view it might not be obvious the universe is pixelated but they would just never be able to manifest that capability what if they're constantly simulating uh cuz it in order to uh appreciate the limits of the Fidelity you have to have an observer what if they're always

simulating a dummer and Dumber Observer yeah what if the sewer has very dumb observers they can't like scientists that are the dumbest possible scientist so like it's it's very pixelated but the scientists are too dumb to to even see the the pixelations that that's like built into the universe always has to be a limitation on the cognitive capabilities of the complex systems that are within it yeah so that se of reality they would still presumably be able to have a a very impressive computational capabilities they' probably be able to simulate Galactic formation all this kind

of impressive stuff but they would be just short of the ability to however you define it create a truly sensient conscious experience in a computer that would just be just beyond their capabilities and so uh Carol pointed out that if you add up all the you know you count up how many realities there should be probabilistically if this is true over here the simulation uh hypothesis or scenario then you're most likely to find yourself in the sewer because there's just far more of them than there are of any of the higher levels oh and so

that sort of sets up a contradiction because then you live in a reality which is inherently Inc capable of ever producing ancestor simulations but the premise of the entire argument is that ancestor simulations are possible so there's there's there's a contradiction that's there's that there's that old quote we're all living in the sewer but some of us are looking up at the stars this this is maybe more true than we think uh to me so there's of course physics and computational fascinating questions here but to me there's a practical psychological question which is you know

how do you create a virtual reality world that um is as compelling and not necessarily even as realistic but almost as realistic but as compelling or more compelling Than Physical reality because something tells me it's not it's not very difficult in the in a in um full history of human civilization that that is an interesting kind of simulation to me because that feels like it's doable in the next 100 years creating a world where we're all prefer to live in the digital world MH and not like a visit but like it's like your scene is

insane no like you're required it's unsafe to live outside of the virtual world and uh it's interesting to me from an engineering perspective how to build that because I'm somebody that sort of loves video games and it seems like you can create incredible worlds there and stay there and uh that's a it's a different question than creating a ultra high resolution High Fidelity simulation of physics but if that world inside a video game is as consistent as the physics of our reality you can have your own scientists in that world that trying to understand that

physics World it might look different presum they'd eventually forget you know give it give it long enough they might forget about their origins of being once biological and assume this was their only reality especially if you're now born you know uh well certainly if you're born but even if you're 8 years old or something when you first started wearing the headset yeah or you could have a memory wipe when you go in I mean it it also kind of maybe speaks to this issue of like neuralink and how do we keep up with AI in

our world if you want to augment your intelligence um perhaps one way of competing and the one of your impetuses for going into this digital reality would be to be competitive intellectually with um artificial intelligences that you could trivially augment your reality if your brain was itself artificial but I mean one one skeptism I've always had about that is is whether it's more philosophical question but how much is that really you if you do a mind upload is this just a duplicate of your memories that thinks it it's you versus truly a transference of your

conscious stream into that reality and I think when you uh it's almost like the teleportation device in Star Trek um but with teleportation quantum teleportation you can kind of rigorously show that um that you know all as long as all of the quantum numbers are exactly duplicated as you transfer over it truly is from the University's perspective um in every way indistinguishable from what was there before it really is in principle you and all the sense of being you versus creating a a duplicate clone and uploading memories uh to that human body or a computer

that would surely be uh a discontinuation of that conscious experience by virtue of the fact you've multiplied it and so I I would be hesitant about uploading for that reason I would see it mostly As is my own killing myself and having some um AI duplicate of me that persists in this world but is not truly my experience typical 20th century human with with an attachment to this particular singular instantiation of brain and body how silly humans used to be used to have rotary phones and um and and other silly things um you're an incredible

human being you're an educator you're a researcher um you have like an amazing uh YouTube channel looking to young people if you were to give them advice how can they have a a career that maybe is inspired by yours um inspired by wandering curiosity a career they can be proud of or a life they can be proud of what advice would you give I certainly think in terms of a a career in science one thing that I maybe discovered late but has been incredibly influential on me in terms of my own happiness and my own

um productivity has been this Synergy of doing two passions at once one passion in science communication and other passion research and not surrendering either one and and I think that tends to be seen as something that's an either or you have to completely dedicate your yourself to one thing to gain Mastery in it that's a conventional way of thinking about both science and other disciplines and I have found that both have been elevated by practicing an each um and I think that that's true in all assets of life I mean if you want to become

the best researcher you possibly can you're pushing your intellect and a sense your body to a high level and so to me I've always wanted to couple that with training of my body training of my mind in other ways besides from just what I'm doing when I'm in the lecture room or when I'm in my office you know calculating something um focusing on your own development through whatever it is meditation for me is often running working out um and pursuing multiple passion provides this uh almost synergistic Bliss of all of them together so often I've

had some of the best research ideas from making a YouTube video and trying to communicate an idea or interacting my audience who've had a question that sparked a whole trail of thought that led down this wonderful intellectual Rabbit Hole or maybe to a new intellectual Discovery can go either way sometimes with those things um and so thinking broadly diversely and always looking after yourself in this uh in this highly competitive and often extremely stressful world that we live in um is the best advice I can offer anybody and just try if you can to it's

very cheesy but if you can follow your passions you'll always be happy um trying to sell out for for the quick cash out for the quick Bookout um can be tempting in the short term looking for exomoons was never was never easy but I made a career not out of discovering exomoons but out of learning how to communicate the difficult problem and discovering all sorts of things along the way you know we shot for the sky and we discovered all this stuff along the way we discovered dozens of new planets using all sorts of new

techniques um we push this instrumentation to new places and I've had an extremely productive uh research career in this world I've had all sorts of ideas working on techno signatures it's it's you know thinking innovatively pushes you into all sorts of exciting directions um so just just try to yeah it's hard to find that passion but you you can sometimes remember it when you were a kid what your passions were and what what fascinated you as a child for me as soon as I picked up a space book when I was 5 years old that

was it I was hooked on space and I almost betrayed my passion at College I studied physics which I've always been fascinated by physics as well but I came back to astronomy because it was my first love and I was much happier doing research in astronomy than I was in physics because it spoke to that wonder I had as a child that first was a spark of curiosity for me in science so Society will try to get you to look at hot Jupiter's yeah and the advice is to look for the cool worlds instead uh

what do you think is the meaning of this whole thing you ever ask yourself why it's just a ride that's how I it's just a ride run roller coaster and we have no purpose it's an accident in my my perspective there's no meaning to my life there's no objective uh deity who is overwatching what I'm doing and I'm I have some fate or destiny it's all just WR riding on the roller coaster and trying to have a good time and and and contribute to to other people's enjoyment of the ride yeah try try try to

make it a happy uh Happy accident yeah yeah I I I see no fundamental um Providence in in my life or in the nature of the universe and you just see this universe is this beautiful Cosmic accident of galaxies smashing together Stars forging here and there and planets occasionally spawning maybe life Across the Universe um and we are just one of those instantiations and we should just enjoy this very brief episode that we have and I think trying to look at it much deeper than that is um is to me uh it's not very Soul

satisfying I just think enjoy what you've got and appreciate it it does seem noticing that beauty um helps make the ride pretty fun yeah absolutely David you're an incredible person I I I haven't covered most of the things I wanted to talk to you about this was an incredible conversation I I just I'm glad you exist I'm glad glad you're doing everything you're doing and I'm a huge fan thank you so much for talking today this was amazing thank you so much Lex it's real honor thank you thanks for listening to this conversation with David

Kipping to support this podcast please check out our sponsors in the description and now let me leave you with some words from Carl Sean perhaps the aliens are here but are hiding because of some Lex Galactica some ethic of non-interference with emerging civilizations we can imagine them curious and dispassionate observing us as we would watch a bacterial culture in a dish to determine whether this year again we manag to avoid self-destruction thank you for listening and hope to see you next time