What Is The Biggest Thing In The Universe?

what is the biggest thing in the universe in 1985 cosmologists believed that they had found the answer a team led by John hucker at the Harvard Smithsonian Center for astrophysics had just completed a survey of thousands of galaxies in the direction of the constellation Koma barones but as they looked through the results they noticed something odd stretched across hundreds of millions of light years a shape began to slowly appear the shape of a person a stickman but the creature with a long slender torso outstretched arms and dancing legs was no monster of ancient legend it

was one of our first glimpses of a super cluster and it was not alone our observable universe turned out to be full of superclusters roughly 10 million in total each one containing tens of thousands even hundreds of thousands of galaxies indeed our own Milky Way is nestled inside of one known as lanaka on one of its outer Limbs and these superclusters are massive at their smallest they are several hundred million light years long composed of lacing entwined branches and clumps of galaxies the largest stretch across the heavens for up to 10 billion light years and

their enormous volume is matched only by their Mass a typical supercluster can hold over 10 million billion Suns worth of material the nearest superclusters are named simply for the constellation we have to peer through to map them the coma the Virgo the Hydra Centaurus the Pavo Indus more distant ones are usually given simple catalog designations unless they break some record in size or distance for example the king Gora supercluster one of the most massive yet mapped was discovered in 2022 by a team of Japanese scientists who named it after the three-headed Nemesis of Godzilla but

despite the Monstrous size of these super clusters their ability to Encompass hundreds of thousands of galaxies at once the way they Bridge across light years with strings of dazzling points they are small for there is a far larger far more menacing class of entity inhabiting our Cosmos the true largest objects in the UN Universe are nothing these are no Titans of ancient myth or kaijus of modern Cinema they the opposite the shadow in the dark for most of our universe is void nothingness there are no lights to trace their structure no gaseous filament to highlight

their nature we can only detect them through their absence the cosmic voids are the single largest objects in the Universe they Define the superclusters they Define our existence everything we know and love our home solar system our galaxy our supercluster all exists suspended on the edge of the abyss and they are the ultimate Destiny of everything in the universe the first Universe simulations run on computers were in the 1960s nbody simulations able to simulate about 100 bodies at a time a far cry from the recent Flamingo Universe simulation with 300 billion elements and certainly not

powerful enough to run Opera our sponsor today the faster safer and smarter Choice than any of the default browsers out there Opera has a great intuitive design with things like Arya a state of the-art generative AI created in collaboration with open AI it is easily accessible and offers options to explain explore and translate any highlighted text on a page very handy when you're looking through physics papers it also has integrated messaging systems for WhatsApp Facebook messenger and more a free inbuilt VPN and ad blocker and most importantly for me great little tab Islands when I've

gone down a rabbit hole on a scientific theory I want to have lots of online books or documents open at once it's an effective and secure browser option that those scientists in the 1960s would have loved to get their hands on so click on the link in the description below to download oppra it's free and you won't be disappointed thanks to oppra for supporting educational content on [Music] YouTube the year was 1978 and astronomers Le Thompson and Steven Gregory had set themselves in exhausting task staying up all night for nearly a week at the kit

Peak Observatory located southeast of Tucson Arizona they were painstakingly recording the positions of dozens of galaxies after confirming the positions of these galaxies on the sky they then fed the light from their telescope into a simple tube that electronically Amplified it the Forerunner of the modern-day digital camera this technology allowed them to access exceptionally dim and distant galaxies far G than the reach they could normally get they were peering further into the universe than any astronomer had before once Amplified they then pass the light from the Galaxy into a spectrometer and from there Thompson and

Gregory could measure the red shift of the galaxies using that to work out the distance there were no computers no sophisticated algorithms no utation Thompson and Gregory were performing a survey of galaxies by manually recording their positions and distances of course they were not the first to perform such a task astronomers had been carefully mapping Galaxy positions for decades but Thomson and Gregory had two tricks up their sleeves two techniques previously unapplied to cosmology one was their use of light amplification but their second trick wasn't one of technology or Theory or even deep Insight it

was a plot a method of displaying the positions of their Newfound galaxies the plot looked like a slice of pizza putting the Earth at the pointy Apex and broadening outwards as the distances from the earth grew though the idea may not seem important it was revolutionary because it allowed Thompson and Gregory to place the large scales of the universe in context condensing the information into an easily digestable format the plan for their survey was to map the galaxies in and around the coma cluster known for decades as a dens gation of galaxies they hope to

use their results to find differences between galaxies that were members of the cluster and those that were in the field the random scattering of galaxies thought to be strewn about the universe but instead they found something [Music] else a vast empty region devoid of any galaxies a patch millions of light years wide that should have been full of galaxies but wasn't a floor in the cosmos the new technique for plotting the positions of galaxies made it too obvious to ignore a dense collection of black dots represent the coma cluster a smattering of Dots here and

there surrounding it and in the middle nothing and so they gave a name to this blank space a void when Thompson and Gregory published their work the astronomical Community was skeptical and sometimes outright hostile we've already taken the measure of the heavens they argued and galaxies inhabited the whole of the cosmos the pair of astronomers had clearly made a mistake perhaps they had some flaw in the design of their survey or maybe their eyes were simply deceiving them they wanted to see a void where there was none driven by their desire to make a dramatic

Discovery no matter what nature ABS a vacuum and the void that they discovered should not and could not [Music] exist but that was in Europe and America for mere months after Thompson and Gregory released their results a trio of Estonian and Soviet astronomers and theorists published the results of their own survey in a different direction of the sky though their survey did not use the pizza shaped diagram they noted the existence of large holes in the distribution of galaxies and on top of this in contrast to the Western view of cosmology Soviet Le scientists had

been deliberately looking for such structures in the west the dominant Paradigm of the large scale structure of the universe simply could not admit the existence of voids cosmological Theory held that the Universe was homogeneous meaning that it was on average roughly the same from place to place at large enough scales the particular pattern of galaxies might be different here and there but statistically everything was the same astronomers had known about the existence of clusters for some time but these were just denser than average lumps in an otherwise random distribution of galaxies for Americans and Europeans

voids simply didn't fit but the Estonian and Soviet astronomers had a different view in the USSR the great theorist Yakov zeldovich had developed an entirely different proposal for the evolution of structure in the universe hypothesizing that large collections of material fracture and Splinter off over time forming ever smaller clumps like clusters and then galaxies in this picture voids naturally appear as a consequence of this continued fragmenting of the cosmos and so it wasn't until 1981 when American astronomer Robert kersner LED another survey in a completely different direction of the sky that the Western astronomical Community

began to accept the reality of the V void kers and his colleagues found what is now known as the booti void which Still Remains as one of the largest known voids in existence the botti's void was larger than any Galaxy larger than any cluster larger than anything in the survey volume the botti's void was the largest single object in existence a vast expanse of emptiness dominating the heavens together with the coma void which the original void discovered by Thompson and Gregory came to be known as astronomers were forced to accept their existence but this raised

big questions first of all very simply how the voids could exist and more importantly how could a homogeneous Universe permit such a blemish this was the birth of the study of the large scale structure of the universe and the discovery of the first voids ushered in our understanding of the true scope of our Cosmos the universe was not as cosmologists had previously suspected an endless series of galaxies occasionally clumped into clusters instead it was far more elegant the Clusters were there but they were only nodes dense kns caught in the tangle of long thin filaments

of galaxies between them hung gigantic sheets walls of galaxies beyond the scale of human imagination and dwarfing them all were the voids the expanses of nothingness that at first defied but then defined the large scale structure of the universe but of course these voids demanded explanation what became increasingly clear in the 1980s and 1990s was that the Universe could still be homogeneous but only on truly enormous scales clusters did not represent the end of greatness even the smallest Cosmic voids utterly dwarfed them they defined and outlined a far vaster structure one that subsumed the entire

observable universe and mapping that greater structure the voids and clusters together led to an even greater challenge finding explanation for its existence as cosmologists worked they would discover void after void and with each new generation of survey they would find vast expanses of emptiness to rival and even surpass the greatness of the bootes and coma voids and each time they found a new gigantic Cosmic void they would be forced to ask if this was truly the end would homogeneity a scale at which the universe was the same everywhere ever be found we do not know

who made the lenux globe but we do know when it was constructed 1510 less than two decades after Columbus made contact between the old and new Worlds the globe features roughly accurate coastlines for Europe Africa and Asia although the proportions are grossly distorted by modern standards South America is present though only its Southern half North America is a series of large islands and there is no trace of Australia or Antarctica but along the eastern coast of Asia which at the time was known partly through secondhand accounts of sailors is written the Latin phrase ik dracones

here be [Music] dragons the globe is one of only two known Maps to actually contain the phrase but the sentiment reached far and wide in medieval mapmaking at the time the world was just beginning to open up to Discovery trade and Conquest geographers were learning more and more about the structure of the world with every Voyage but for every measurement and Survey of a coastline or location of a city much remained unknown and so these early mapmakers faced a difficult decision what should they put in those blank spaces the answer was simple Fantastical illustrations of

dragons serpents lions and other dangerous creatures to create a sense of wonder and mystery of the unknown lands of the world and to warn the viewer that Beyond the Lights of civilization lay hidden dangers but that sense of lurking danger of the unknown in the dark did not die with the map makers of the Age of Exploration as astronomers continue to pierce farther into the heavens they would also find empty places and boundaries of their knowledge our maps of the local universe begin with the known the named the safe our solar system a single star

surrounded by eight planets and innumerable smaller objects is but one of hundreds of billions inhabiting our home the Milky Way this Galaxy with its serenely spiraling arms and dense Cor four spans 100,000 Li years in diameter though it's less than 30,000 Li years thick compared to that even the greatest possible extent of our solar system is at the same scale as a single microscopic cell compared to an entire human body sitting roughly 2 and a half million light years away from us is our nearest major neighbor Galaxy the Andromeda which contains up to a trillion

individual Stars also gleaming brightly in a beautiful spiral pattern together with with triangulum and a scattering of other dwarf galaxies we form the local group it's a rather uncreative name but it's fitting it's a small group of galaxies bound together through their Mutual gravitational attraction whatever fate befalls the universe we will remain by each other's side the next nearest major cosmological object to us is a cluster specifically the Virgo named after the constellation you must look through to observe it clusters are the largest gravitationally bound objects in the cosmos they are dense cities homes to

a thousand or more galaxies sometimes spanning millions of liers in diameter the Virgo cluster sits roughly 65 million light years away from us and it's at these scales that we truly enter into cosmological considerations the Virgo cluster sits as the centerpiece of what's known as a super cluster the largest glomeration of matter in the entire universe though they are not yet gravitationally bound meaning that the mutual self-gravity of all the galaxies within them have not completely pulled them together superclusters are still forming the name for our local super cluster is the Virgo supercluster which is

an unfortunate bit of duplicated astronomy terminology the Virgo cluster Beats at the heart of the Virgo supercluster which is home to dozens of groups just like our local group group however more recently astronomers have discovered that the Virgo super cluster is just one branch of an even larger supercluster named lania taken from the Hawaiian word for immense Heaven the name is appropriate because lanaka contains four branches each large enough to count as a super cluster in their own right up to 500 individual groups and clusters and over 100 100,000 individual galaxies all forming a tangled

branching reaching Mass stretching over half a billion light years the scale of lanaka compared to a single Galaxy is roughly the same as the scale of a City compared to a person but considering that each galaxy has tens if not hundreds of billions of individual Stars you can consider lanaka as a truly great Metropolis the equivalent of an immense City housing quadrillions of people its star count roughly equivalent to the number of ants that inhabit the Earth and lania is not alone beyond our home supercluster sit even more the Hercules supercluster the shapley supercluster the

Perseus Pisces beyond that the sheer number of known superclusters outpaces our ability to give them individual names and so they are known simply as numerical ENT trees on a computer catalog recordings of their position in space and lists of their member galaxies taken together all the interconnected superclusters create the cosmic web the largest structure in the entire universe every corner of the observable Cosmos with a diameter of 95 billion light years is filled with this series of supercluster connected to supercluster a network of galaxies traversing the known universe where the Tangled branches meet massive clusters

like Virgo appear with long thin filaments stretching between them and Broad walls sectioning off entire portions of the cosmos the size of the cosmic web is almost impossible to describe by analogy you could say that galaxies are compared to the cosmic web the same way that individual cells are compared to the human body but for this to truly work our cells would have to be a million times smaller than they are in reality the cosmic web is simply so vast so large that individual galaxies appear as nothing more than tiny dots of light each Galaxy

home to hundreds of billions of individual Stars stretched across 100,000 light years but as dazzling and Inc comprehensibly vast as these superclusters are they are almost inconsequential to the Grand tapestry of our universe instead by volume the cosmos is almost entirely void all galaxies with the exception of the ones buried deep within the hearts of cluster live constantly on the edge never far from the vast Gulfs of relative nothingness that consume the universe and so in this sense the name Cosmic web is apt just as the threads of a spiders web also draw the eye

but take up almost no space so too does the light of Galaxy after Galaxy Light Up The filaments and clusters and yet a dwarfed into nothingness by the nothing us between astronomers find it difficult to map the voids closest to us since they are so big and so empty that they require broad comprehensive surveys to reveal them but we do know that the nearest void to the Milky Way is the local void which by itself is nearly 200 million light years across beyond that we have the northern and southern voids the giant void and the

bootes and coma voids Beyond them has cosm ological surveys continue to push deeper into the universe sit even more empty spaces arranged raggedly between and among the superclusters and yet despite their names each void is not perfectly empty they certainly that galaxies as the early astronomers found to their amazement but there are innumerable microscopic objects floating through the cosmos bits of hydrogen and helium cosmic rays and neutrinos blasting here and there and the ever present radiation from the cosmic microwave background but the density of matter within a void is definitely extremely low cosmologists typically Define

a cosmic void as any region of the universe with a density lower than 20% of the cosmic average and considering that the cosmic average is roughly one hydrogen atom per cubic meter of space that's very low in contrast a Galaxy will have at minimum millions of times greater density than the cosmic average and so this means that deep within the hearts of voids aside from the occasional stray hydrogen atom or passing cosmic ray you can find yourself millions of light years away from any significant structure Galaxy or even star they are by far the lonliest

places in the universe indeed these voids aren't just empty of matter they are also so empty of Dark Matter Dark Matter makes up over 80% of the mass of almost every single Galaxy and cluster in the cosmos even though it is completely invisible and made of some particle unknown to Modern physics and this dominance of Dark Matter extends to the filaments and walls of the cosmic web itself what we see in the galaxies are just the bright lighthouses on a distant dark Shore giving us faint glimpses into the true structures beneath and so the cosmic

web is made of dark matter and in turn the cosmic voids are empty of Dark Matter although we cannot directly observe the distribution of dark matter in observations because we're limited to observing light emitting galaxies we can see the full glory of the Dark Matter Cosmic web in cosmological simulations the densest concentration of Dark Matter correspond to the appearance of clusters while threads of Dark Matter contain filaments of galaxies and where there's no Dark Matter deep in the greatest of cosmic voids there are also no galaxies Galaxy surveys like the Sloan digital Sky survey have

discovered tens of thousands of voids in the universe and even that represents only a tiny fraction of the observable Cosmos the smallest voids are roughly 20 million light years in diameter and astronomers find them embedded inside of much larger accumulations of matter relatively tiny empty Pockets buried within superclusters whereas the largest voids stretch across significant fractions of the known universe separating their boundary superclusters by a billion light years and more and it's in these enormous voids that we find the beginning of a potential problem the voids are big and empty which was a surprise to

early astronomers but we do now have an understanding of how they along with the brightly lit superclusters formed over the course of billions of years of cosmic history but some observations suggest that the very largest voids may be a little too large that they break our understanding of cosmology that they shouldn't belong in the universe these are the so-call super voids the entrance was in the bottom corner of a sinkhole completely covered from above stumbled upon completely by accident the cave was discovered by a local Vietnamese logger searching for wood near the border with Lao

hearing the sound of Rushing Water his curiosity Drew him within the entrance it was Pitch Black but judging by the feel of the air I thought I was walking into a huge space the strong wind blowing felt like something from the underworld he returned home forgetting the exact location of the entrance not finding it again until 20 years later in 2008 the next year HOH Hine guided the British cave research Association into the cave and multiple Expeditions over the course of years Finally Revealed the full extent of the system which stretched in nearly 10 kilm

the cave called Sun dong which roughly translates this Cave of the mountain river is the largest in the world it even has its own ecosystem and weather and it spent millions of years hiding in plain sight undisturbed our world is full of hidden wonders empty spaces lingering undiscovered right beneath our feet and above our heads so what else are we missing in the universe what caves what empty spaces lurk in the vast reaches of the cosmos and what do these Cosmic caves teach us the voids and super voids are there between and among the great

structures of the universe and we've only just begun to explore their terrible [Music] depths but despite their enormous Universe dominating size these voids have not always been this large just like their counterparts the walls filaments and clusters the voids began their lives as subatomic fluctuations in the quantum foam that permeates all of space and time these fluctuations were briefly Frozen in place during the tumultuous Epoch of inflation that hypothesized event which cosmologists suspect occurred well before our universe was even once second old increased the size of the cosmos by multiple orders of magnitude in the

process subatomic variations in SpaceTime enlarged drastically to become very small variations in SpaceTime but what came after is all due to gravity these tiny pockets of curved SpaceTime had slightly stronger gravitational attraction which allowed matter to begin pooling in them as matter piled together those clumps had an even stronger gravitational pull which in turn increase their ability to pull in even more matter from their surroundings like a cave that starts as a small stream of water carving a space for itself in the crust over the next hundreds of millions of years the slow but persistent

machinations of the gravitational force would begin the process of building the cosmic web the first Stars Gathering to a light the first galaxies the first galaxies assembling into the first groups the beginnings of the Wisp thin tendrils of the filaments connected ing them sending more material funneling into the initial massive clusters but in our universe when the rich get richer the poor get poorer as matter continued to accumulate onto the galaxies and groups and clusters it had to come from somewhere and it came from the [Music] voids starting their lives as one part per million

depressions in density scarcely noticeable from any other patch of the universe the voids emptied out and enlarged compared to the massive structures which built themselves up from violent collisions and Furious mergers the early voids LED quiet Placid lives they simply got bigger matter pulled out of them and into their surroundings at first slowly then at a quicker Pace as the gravitational attraction of the cosmic web grew larger over the same hundreds of millions of years that saw the emergence of the first stars and galaxies the first voids also appeared in tandem beginning as Tiny forgotten

pockets and steadily increasing their volume until they quickly dominated the cosmic web voids occasionally merge just as galaxies and clusters do but when voids come together it is a much less violent Affair if a wall of Galaxy separates two voids voids for example then over time the galaxies in matter in that wall slowly disperse making their way to the dense clusters on the perimeter of the wall when enough material leaves the wall the two voids become a single larger entity no Titanic Collision no great release of energy just the inexorable expansion of nothing this kind

of flexibility made it difficult for cosmologists to precisely Define a void but recently they have come up with a unique Solution One inspired by a completely different field of study geography geographers often want to identify the sources and flows of water on a land mass discovering the path of water AIDS in understanding ecosystems mapping and mitigating the effects of pollution and measuring the availability of groundwater for drinking irrigation and industry to do this geographers create a map known as a watershed a watershed is a region where all the water flows to the same destination watersheds

are typically divided by high topographical features like mountains and ridges if you imagine pouring rain water over the continental United States for example you'll find some water flowing towards the Pacific and some water flowing towards the Atlantic the Rocky Mountains serve as the ridg line between these two different wall Watershed regions and so if we imagine the high density regions of the universe like walls and filaments as high peak Mountains and the low density voids as The Valleys between them we can perform a similar kind of analysis if we imagine pouring water throughout the Universe

allowing that water to run from the heights of the filaments and walls and Into The Valleys of the voids this Watershed technique provides cosmologists with a clear cohesive definition of a oid they are simply the low density regions of the universe defined by the surrounding topology just as the watersheds on a land mass are defined by the mountain peaks and ridges that surround them and determine where water flows using this technique cosmologists have been able to leverage existing Galaxy surveys like the Sloan digital Sky survey and the dark energy survey to map and catalog tens

of thousands of individual voids in the nearby universe and in those surveys cosmologists have begun to identify a hierarchy of voids the largest voids in the universe are not completely empty instead they contain small collections of dim red galaxies and those galaxies are not scattered about randomly inside the voids deeper analysis has revealed that those galaxies as feeble as they are arrang themselves into a cosmic web in miniature with small groups and thin tenuous filaments and sitting between those tenuous filaments a voids unto themselves nestled within the volume of the greater voids imagine a gigantic

cave system with a main chamber leading to smaller empty spaces divided by thin walls of rock that is what cosmologists are finding in the cosmic web and Analysis of voids in simulations of the cosmic web reveal EV even deeper levels with subub voids nestled inside of sub voids nestled inside of voids indeed the structure of voids in the universe is fractal like in nature with the same Cosmic web structure appearing again and again from smaller to larger scales however we cannot directly observe all the levels of this nested hierarchy because the cosmic web mostly exists

in dark matter with only a portion of it illuminated with galaxies but where does that fr cile like hierarchy stop are the largest known voids like the bootes void the largest possible voids in existence or are they mere sub voids of even larger expanses of emptiness the super voids one hint at the existence of super voids comes from an unexpected Source the cosmic microwave background or CMB the CMB is the leftover light generated when our universe was only 380,000 years old at that time the universe was a million times smaller than it is today and

had an average temperature of around 10,000 Kelvin forcing all the matter in the cosmos into a state of a high density high temperature plasma as the universe expanded from that state the plasma cooled becoming a neutral gas and the first atoms appeared this process also made the universe transparent to radiation and that radiation flooded the young Cosmos persisting to the present day as a bath of low energy microwave radiation the CMB isn't perfectly smooth as it contains one part in a million variations in temperature cooler and hotter spots of various sizes cosmologists understand the statistics

of these spots both their size and their temperature and use them to glean an enormous amount of information about the state of the young universe except one known simply as the cold spot a particular region of the CMB is both exceptionally large and exceptionally cold in fact it's so large and so cold that standard cosmological models could not account for it it is an anomaly there is to date no widely accepted explanation for this cold spot and theories have ranged from radical changes to our cosmological models to the tantalizing possibility that the cold spot is

the intersection point of our universe with another but the most likely explanation is that when we look at the cold spot we're really just looking at a vast shallow combination of voids a super void the super void can affect our view of the CMB because of the fact it has not always been here it took time for the supervoid to evolve out of the primordial Cosmic web when light from the CMB first entered the supervoid long ago it was relatively small and shallow but the super void is so big that it took hundreds of millions

even billions of years to make the crossing in that time the Super void widened and deepened and so when the light finally made its way out of the other end it found found itself having to overcome a much deeper gravitational well than when it entered this sapped energy from the cmbb light resulting in a cold spot in that direction and the cold spot super void also known as the aridus super void is not alone another Super void the cares vatz super void also known simply as the giant void sits over 1 and A2 billion light

years away but stretches across a vast 1.3 billion Li years diameter but largest of all in 2013 a trio of researchers Ryan Keenan Amy Barger and Lennox cowi proposed the existence of a truly enormous supervoid this void known occasionally as the KBC void after its discoverers or the great pole would be the largest void ever known potentially up to 3 billion light years in diamet on top of this despite all the large structures surrounding the Milky Way galaxy like the lanaka and shapley superclusters this supervoid would contain them all with its volumes so large that

it could contain all these structures and still have an average density low enough to be called a void the trio of astronomers proposed the existence of this super void to help explain discrepancies in the measurement of the Hubble constant which is the present-- day expansion rate of the universe measurements taken from the early Universe like the CMB differ from measurements taken in the modern Universe like with Supernova since the Interiors of voids and super voids have different rates of expansion the KBC void with its enormous volume surrounding us could explain the difference however the existence

of the KBC void remains highly disputed as astronomers have not found additional independent evidence for its existence regardless of the existence of the disputed KBC void the other known super voids stretch if not outright break our understanding of cosmology like a cave that could never have formed in geologic time scales given our knowledge of cave formation processes the problem is that voids May simply be too big we understand the scale where the universe becomes homogeneous as a product of gravity and time we know what the early Universe was like because we have highly detailed maps

of the size of matter fluctuations thanks to our observations of the CMB from there we can take our understanding of how gravity works and the fundamental components of the universe to trace out the ensuing evolution of the cosmic web and the results of those calculations tell us that if we zoom out to scales of 300 million light years the universe should be roughly the same from place to place in other words one 300 million Lightyear patch of the universe should be the same at least in a statistical sense as any other 300 million Lightyear patch

to get a better sense of what homogeneity means in this context imagine taking a square patch of land and measuring how many people live within that patch obviously people are not spread homogeneously across the Earth there are far more people crowded into dense cities far fewer in the rural outskirts and almost nobody in deserts if your patch is too small say 100 km across then your patches will be very different some will capture nothing but inhospitable desert or mountain ranges While others may be centered on bustling cities but if you make your patch big enough

then every patch will at least get some cities many rural areas and Broad areas of uninhabited regions that is the homogene scale where every patch has roughly the same average population and so the presence of the largest voids potentially threatens our understanding of cosmology because they are like vast deserts that stretch farther than even our biggest plausible patch the largest super voids are larger than a purported scale where the universe should become homogeneous and so the question becomes are these super voids just randomly large through sheer Cosmic accident and don't otherwise affect our understanding of

homogeneity or are they so big that we need to revise our understanding of how large structures appear and grow in the cosmos if a cave on the earth is too big and too deep it starts to threaten our understanding of [Music] geology there is no firm answer within the the cosmological community to this question some cosmologists argue that the known super voids are far too large and violate our current understanding of homogeneity and therefore Force us to reconsider our cosmological models perhaps a new fifth force of nature or some new element in the cosmos explains

how the super voids have grown so massive but at the same time other cosmologists argue that we should expect the occasional supervoid Even in our nearby patch of the universe based on results from extremely complex computer simulations of the growth of structure while there remains no resolution to this debate one thing is clear the voids have not stopped growing they emerged billions of years ago as Tiny pockets of low density embedded in a sea of matter they have grown to their present scale where they dominate the volume of the universe and over the next few

billion years they will come to rip apart the cosmic web and leave nothing but Darkness [Music] behind there are many dangers lurking in the cosmos many processes whose sole desire is to grow expand and and consume simple diseases like viruses and bacteria are limited in their growth by the resources available in the biosphere and competition with other organisms but on the very largest scales there is nothing that can stand in the way of all consuming multiplication the cosmic voids are more than mere empty holes in the distribution of matter in the universe they were once

much smaller than they are today they're not done growing and in a strange trick of physics they there is nothing that can ever stop them we live in an expanding Universe with every passing day our Cosmos grows larger and larger another way to State this is to say that the average distance between galaxies grows with time there may be occasional mergers here and there for example the Milky Way galaxy will merge with Andromeda in roughly 5 billion years but at large enough scales this expansion becomes apparent and in the late 1990s astronomers discovered that this

expansion is accelerating the expansion of the universe is getting faster and faster every day even to this day nobody knows for sure what's causing this accelerated expansion but it does have an appropriately mysterious name dark energy in the simplest and most straightforward models of what Dark Energy could be physicists treat it as a fundamental aspect of the vacuum of SpaceTime it's itself this means that if you were to take a box and empty out all the particles and the radiation leaving behind a perfectly empty volume you would still have a box filled with dark energy

this dark energy has an extremely weak repulsive gravitational effect which means we can't notice the effects of it where there are large concentrations of mass like galaxies and clusters but averaged across the entire universe it becomes dominant causing the universe's expansion to accelerate and this means that there is only one place in the universe where Dark Energy dominates the cosmic voids the Deep depths of vast emptiness that Define the nature of these voids means that they are not truly empty they are indeed void of matter and radiation but they are filled to the brim with

dark energy a disease that is infecting the universe it is within the voids not the galaxies not the filaments not the Clusters where the expansion of the universe is accelerating and the cosmic voids aren't just blandly expanding as matter accumulates around their edges because of dark energy they are literally pushing on their borders driving more and more matter away from their centers they are pressing on the walls between them thinning them out they are squeezing on the filaments breaking them apart and this when will not stop in fact it will get worse as the universe

expands and the voids grow larger there will be even more dark energy in the universe allowing dark energy to become more powerful Dark Energy first began to dominate the evolution of the universe about 5 billion years ago it was in that era that the ground story of structure formation in the cosmos from The Humble seeds planted in the first chaotic moments of inflation to the spinning of the grandest structures in the universe began to come to an end a subtle symptom that something was deeply sick in the cosmos this means that the great superclusters that

stretch and wind and twist for hundreds of millions of light years will never truly come together the voids surrounding them will crush them to death breaking the tenuous bonds between the Clusters and driving all matter as far away from itself as it possibly can in only a few billion years the cosmic web will be destroyed consumed by the ever growing voids within it no more filaments no more superclusters no more walls only isolated groups and clusters separated by an ever increasing vast expanse of absolute nothingness of voidness the far distant future of the universe belongs

to the void they will win they will leave nothing behind as they ravage the universe but in an ironic twist voids are Humanity's most crystal clear windows into the deepest layers of the past when cosmologists try to understand the Universe they only have two choices one choice is to search for Direct observational evidence from specific epochs like the cosmic micro background but the CMB is fundamentally limited it was a singular event that happened only once briefly in the entire history of the cosmos and so it only carries so much information with it whereas the other

choice cosmologists have is to observe as much of the modern day universe as possible building maps of the distribution of galaxies groups clusters and voids and use those Maps combined with our knowledge of physics to rewind the clock and try to learn what the universe is made of the contents of the universe the amount of normal matter dark matter and dark energy determine how the cosmic web evolves a universe with much larger strengths of dark energy for example would have never formed a cosmic web in the first place while a universe with too little dark

matter would have only formed weak and feeble galaxies the story of the entire history of the universe is written in the cosmic web a vast Treasure Trove of data that can tell us what the universe is made of how it evolved over billions of years and what its ultimate fate will be but the cosmic web is enormously complex in principle we can rewind the evolution of every cluster and every Galaxy back to the primordial soup of hydrogen and helium bil of years ago after all it's just a bunch of particles interacting with each other through

the fundamental laws of physics but in practice this is nearly impossible for example your body contains trillions upon trillions of hydrogen atoms these hydrogen atoms have inhabited the cosmos for over 13 billion years the properties of those same hydrogen atoms their positions their velocities the particular combinations and Arrangements inside your body contain some faint memory of the universe as it was all those billions of years ago but discovering those early conditions by examining your body would entail figuring out every single interaction that those hydrogen atoms participated in during all those billions of years so even

though there is an echo of the early Universe still inhabiting your body finding it is nearly impossible and the same holds true of entire galaxies and clusters they are so complex so busy with star form magnetic fields cosmic rays supern noi and all manner of intricate physics that we can't ever hope to disentangle the primordial conditions of the universe by observing them but the voids are simple the voids are empty the voids are clean the voids are boring they have barely changed in billions of years of Cosmic history though they have grown bigger and occasionally

merged with their neighbors all those processes are slow careful deliberate the voids are therefore relatively unevolved when it comes to Great Cosmic objects they provide the perfect window into the early Universe if you want to know what the cosmos was like billions of years ago you can look into the voids and because the voids are filled with dark energy they also hold deep within them the Ultimate answers to that vexing mystery even though dark energy is thought to suffuse every cubic cimer of SpaceTime it's impossible to Define its nature inside of dense regions like solar

systems galaxies and clusters there's simply too much other stuff and all the associated complex dynamics that go along with that stuff to figure out how dark energy works but not in the voids voids are brimming with dark energy they are Laboratories where cosmologists can go to study the deepest workings of the dark side of the [Music] cosmos and so for decades Cosmic voids have languished in the shadows a forgotten and ignored byproduct of traditional surveys of the bright objects of the universe their initial Discovery was even ridiculed and mocked as cosmologists didn't believe that the

Universe could possibly create such vast regions of absolutely nothing but in the past decade interesting Cosmic voids has exploded thanks to new techniques like the Watershed to reliably find them within surveys of galaxies and now that those surveys are broad enough cosmologists have more than just a meager handful of voids to study they have thousands to catalog the European Space agency's uclid Telescope launched in 2023 will conduct a massive survey mapping the positions of millions of galaxies where the study of voids was once on the fringes of cosmology the uid research team now includes a

group devoted to finding Cosmic voids within the survey and using them to understand dark matter and dark energy the same is true for NASA's next Flagship Mission the Nancy Grace Roman telescope which also has a working group devoted to their study and so with every passing year the universe appears to be teaching us something important about the nature of voids if we want to understand the deepest Mysteries of the cosmos test the limits of our theories and find clever ways to push past them into a new understanding of physics we must learn how to stare

into the deep Abyss [Music] you've been watching the entire history of the universe don't forget to like And subscribe and leave us a comment to tell us what you think thanks for watching and we'll see you next time [Music]