Atom: The Key To The Cosmos (Jim Al-Khalili) | Science Documentary | Reel Truth Science

[Music] [Music] [Music] as we gazed up at the heavens we asked that where we had come from how all the stars were created how all the elements were made even how the universe itself had begun one of mankind's greatest achievements is that we've answered these questions what is truly remarkable is that this understanding has come through the study of the smallest building blocks of matter atoms as we peered inwards we realize we could explain what we saw when we peered outwards the atom has helped us solve the greatest mysteries of existence [Music] [Music] everything in

the world we see is made out of tiny objects called atoms and yet we only prove their existence at the beginning of the 20th century the first shot was to discover how small they were less than a millionth of a millimeter across there are trillions in a single grain of sand amazingly we now have a pretty good idea of the number of atoms in the known universe now given the vastness of the universe and the mine muteness of the atom it's not surprising that this is a mind-numbing huge number it's one followed by over 70

zeroes that's a trillion trillion trillion trillion trillion trillion atoms we don't only know the raw number of atoms in the cosmos we also know that they come in 92 different flavors these are called the elements and you'll recognize many of them as familiar parts of the world around us oxygen iron carbon tin gold and so on everything in the universe the Stars the planets the mountains the Seas the animals you and me we're all made with these atoms or combinations of them it's an astonishing human achievement that we now know not only how many atoms

there are in the universe and how many different types there are but why they exist at all we can now explain how every one of those trillion trillion trillion trillion trillion trillion atoms was created it turns out that the answer to the mystery of creation itself lies within the heart of each and every atom in the universe [Music] the story of how we paint understand creation itself started over 100 years ago in a small laboratory in southeast Paris this piece of papers are remarkable artifacts it's from the notebook of the woman who first studied radioactivity

the chemist Marie Curie it's incredible a hundred years later and this piece of paper still spitting out radioactive particles still stuck to the paper are tiny but intensely radioactive particles of a substance that Marie Curie discovered in 1898 a substance she called radium it was a sensational discovery for one primary reason though radium looks like an unremarkable gray metal it contradicted all of their known laws of silence because radium pumps out invisible yet powerful rays of energy which could funk sealed photographic paper and burn human fresh also radian are cleared to contain within it an

inexhaustible store of energy curie works out that a gram of radium a piece much smaller than a penny contains more energy than a hundred tons of coal to the scientific community radioactivity exciting thing the brightest minds of a generation clamor to study and the price of radium is most potent source soared to thousands of pounds per ounce [Music] radioactivity didn't disappoint in 1918 it produces its greatest revelation yet the revelation the revelation was the radioactivity allowed humanity to fulfill an age-old dream to become alchemists alchemy the power to change base metals into gold the quest

for the so-called Philosopher's Stone which has the magical ability to transmute one substance into another has been an obsession for centuries it conjures up wonderful tales of sorcery and wizardry as anyone who's read Harry Potter knows very well the power and wealth that would surely come to anyone who mastered alchemy seduced many great scientists and thinkers like Isaac Newton Robert Boyle and John Locke all of them tried to change one element into another and all of them failed then in 1919 the secret of alchemy the mystery of the Philosopher's Stone was finally revealed not in

a wizard's den but in the physics department at Manchester University the world's first true alchemist is Ernest Rutherford allowed straight-talking New Zealand Rutherford had come to dominate study of radioactivity he had wonderful intuition and was fearless leap repaired to challenge conventional wisdom and alchemy would require Ernest Rutherford to follow his intuition deep into the unknown the discovery was almost accidental it began when one of rather four students noticed that when radioactive materials like radium were placed inside a sealed container of ordinary air mysteriously small amounts of the gas hydrogen begin to appear now this was

bizarre ordinary air contains virtually no hydrogen and yet in the presence of radioactivity it was appearing out of nowhere this was precisely the kind of problem that Rutherford now at the height of his powers as an experimental physicist loved and he flung himself at it he began by isolating all the different gases that make up the air we breathe nitrogen oxygen water vapor and carbon dioxide and studied how each of them behaved in the presence of radioactivity and then Eureka Rutherford realized that in the presence of powerful radioactive rays the gas nitrogen which makes up

about 80% of the air we breathe changes into two new substances the gases oxygen and hydrogen then and there Rutherford had transmuted one element into two others he'd become an alchemist and radium with his powerful radioactivity was the Philosopher's Stone the Chris Haley Brotherhood as the first alchemist but in fact that was the mister the inside not just the answer but a strange object at its center its tiny heart since of this achievement remember Rutherford and his contemporaries at language and only a sketchy idea what he hasn't once but they did have an idea it's

um and it's mind-numbing Li tiny one-tenth of a millionth of a millimeter across let me put it another way there are more atoms in a single glass of water than there are glasses of water in all the oceans of the world and Rutherford now also knew that the Adam had structure that within the Aten there was a subatomic world he pictured each atom like a tiny solar system at its center was an object which Rutherford called the nucleus orbiting this like planets were the electrons but what on earth was the nucleus Rutherford was convinced that

alchemy had shown him the answer to understand how Rutherford did this we have to get inside his head to think like he did Rutherford had fantastic intuition coupled with an intensely practical approach to science so he hated ideas that relied on complicated mathematics when it came to the atomic nucleus Rutherford looked for the simplest idea that worked and what worked was to imagine that the nucleus is made of tiny rigid spheres like snooker balls using this incredibly simple image Rutherford could construct all the elements in the universe he could explain how the huge variety of

different atoms are made of the same basic components so here's how it works hydrogen which is the simplest element consists of just one fear which Rutherford called a proton which is the Greek word for first all the other elements are made by adding more protons to the nucleus it's as simple as that so helium which is the second lightest element comprises of two protons lithium has three carbon which is the element that's the basis of all life has six protons the oxygen that we breathe has eight and uranium which is the heaviest naturally occurring elements

has ninety-two protons this was Rutherford's inspirational idea that each element is defined by the number of protons in its nucleus it's a wonderfully elegant and simple idea an idea that explains how so much of the universe we see around us is constructed but a scientists often find nature is never quite as simple as it seems at first sight sure enough a big problem emerged with Rutherford's protein and it was to be one of Rutherford's own protégées who was the first identified Frances Astin was an interesting character as a young man he enjoyed the adventurous outdoors

and was into skiing and motor racing and apparently about 1909 he discovered surfing off Waikiki Beach in Hawaii but he soon realized that the call of the physics of oratory was greater than the call of the waves and was while at Cambridge that he invented an incredible piece of equipment that's now housed here in this rather austere and plain-looking building the Cavendish laboratory this is Astin's original spectrograph it's an amazing piece of equipment because with it for the first time scientists were able to weigh individual atoms so incredible it looks a bit like a gun

it's a very strange shape now they could weigh atoms accurately they discovered that there was a fundamental problem with Rutherford's model of the nucleus basically the numbers didn't quite add up all the atoms of the known elements apart from hydrogen were much heavier than they should be for us as helium with two protons should weigh twice as much as hydrogen with just one in fact it's four times as heavy rather fir'd realize this could mean just one thing apart from the proton there's something else inside the atomic nucleus but what [Music] [Music] Chadwicks built this

in 1932 and to think that with just this tiny little piece of equipment he discovered the missing ingredients of the atom for me as a as a practicing nuclear physicist this really is an amazing device when I think of the huge accelerators that are built today to conduct experiments to probe the nucleus of the atom it's really all inspiring in its simplicity really it put a source of radioactivity at this end of the tube and the radioactivity then struck a small target in the middle here and then out of the target came new particles that

sprayed out of this end here it's bit like an atomic gun shooting out Rutherford's missing particles what Chadwick discovered was that along with the proton there's another kind of particle inside of the nucleus it weighs almost exactly the same as a proton but is much more elusive because it carries no electrical charge technically we say it's electrically neutral hence its name than Neutron and it immediately solved the problem of the weight of atoms so helium is four times as heavy as hydrogen because along with its two protons it contains two neutrons and oxygen has eight

neutrons along with its eight protons making it 16 times as heavy as hydrogen so in 1932 the atomic family was complete scientists announced that every atom in the universe is made of just three basic components electrons tiny particles orbiting a nucleus which in turn is made of protons and neutrons [Music] over Christmas 1932 Center of atomic physics Institute Inc open sea celebrate the neutrons discovery completion of the nuclear trinity by writing a musical about that which experiment has far for theory had no party is always written more than sound to put your mind and heart

in good luck you heavyweight as such we welcome you with pleasure but passion ever spins a pot and Gretchen is my treasure some of the great names in physics took part in this music the excitement was primarily due to one thing they knew they stood at the threshold of an entirely new kind of science with entirely new rules when now nuclear physics trying to renew a physics was this although physicists now knew the tiny nucleus was made they couldn't explain how it all fall together in fact it was worse than that the existing laws of

physics predicted that every atomic nucleus should self-destruct [Music] the main problem was this all protons the key ingredients of the atomic nucleus have positive electric charge and things with the same charge repel each other just like these magnets look so just like these magnets if two protons get close together they should then just fly apart but weirdly inside the atomic nucleus they don't dozens of protons can stick together alongside each other so what sticks them together what stops the protons from flying apart the answer was big news it was nothing less than an entirely new

force of nature for centuries humans had only ever encountered two natural forces gravity which pulls us down to the earth and electromagnetism but now hidden inside the atomic nucleus was something completely new it was called the strong nuclear force and the easiest way to imagine it is with some velcro if I put velcro around these magnets they start to behave slightly differently at first they repel each other just as before but when they get close enough the velcro kicks in and they stick the effect is very short-range but very very strong and it's exactly the

same with protons the strong nuclear force explains what holds the nucleus together [Music] strong nuclear force works between all protons and neutrons but what is truly surprising about it is its strength it's by far the most powerful [Music] [Applause] more than a trillion trillion trillion times stronger than gravity think about it this way if I was pulled down to the earth not by gravity but by the strong nuclear force then I'd weigh trillions of times more than I actually do in fact I'd weigh more than the entire galaxy but the reason I don't weigh that

much is because the strong nuclear force is only felt down at a distance of a trillionth of a millimeter with the strong nuclear force humans finally began to get a glimpse of what was actually going on inside the atomic nucleus roughly speaking all nuclear behavior is down to a balance between the strong nuclear force squashing the protons and neutrons together and the electric charge on the protons forcing them apart physicists realized that picturing the nucleus as a battlefield between different elemental forces solved one of the oldest mysteries of all time it's this a question that

humans have asked ever since the dawn of time is how does the Sun Shine now sunlight is the source of all life on Earth but how is it made it's all to do with the forces in some of the atoms that make up most of the Sun hydrogen this is how it works the nucleus of a single atom of hydrogen consists of just a proton and every now and again inside the high-pressure high-temperature cauldron of the Sun this proton can get squeezed up close to another and bang the strong nuclear force kicks in and fuses

them together now this is the process that eventually leads to the creation of a helium atom and it's accompanied by the release of energy as a burst of light and heat it's a bit like slamming two cymbals together and releasing a burst of sound [Music] Hartigan fusing into helium and the energy released is what we see and feel as sunshine this process of two hydrogen nuclei slamming together and releasing energy became known as nuclear fusion determine between the strong nuclear and electromagnetic forces as they strive dominant the nucleus does more than just power the Sun

is at the heart of everything but in the late 1930s before people figured out that story nuclear physics it's something much closer to home in no uncertain terms it redefined the history of mankind right here on earth the atom bomb changed everything the excitement of pre-war scientific research the days when physicists sang songs about their discoveries were over Robert Oppenheimer summed up the grim mood with these words the physicists have known sin and this is a knowledge which they cannot lose [Music] the terrible irony of the atomic bomb is that because of the scientists in

because of that knowledge that cannot be lost something of great significance did emerge something that would ultimately reveal the full story of the 14 billion years of the entire universe the had caused a massive two billion dollars to be poured into nuclear research people now knew an astonishing amount about the atom and its nucleus specifically scientists had detailed measurements of how stable unstable different atomic nuclei were that stability was a direct result of the battle between the strong nuclear force holding the nucleus together and the electromagnetic force pushing it apart in some atoms the balance

tipped towards the strong force making them very stable but when the electromagnetic force had the upper hand they were inherently unstable by the late 40s scientists began to investigate the implications of the way nuclear stability of atoms varies they noticed one very strange fact about the nuclear stability of one particular atom of all the 92 different elements of the 92 different types of atoms that make up the universe around us gases like hydrogen and oxygen solids like carbon and silicon metals like gold and silver one is special so what makes iron so special it stems

from the unique structure of its nucleus the 26 protons along with the neutrons combine in a very special way to make iron incredibly stable for some reason nature has decreed this as the number that allows the strong force and magnetic it makes iron now we can understand why fusion occurs lighter atoms can combine together to become more iron like and fission is the opposite process atoms heavier than iron can split apart into lighter more iron like pieces so all elements seek the stability of iron [Music] underpins the whole history of the cosmos the best way

to understand this is to imagine the relative stability of atoms as a couple of graphs here's what they show the very lightest elements hydrogen and helium are not quite as stable as they could be they'd like to be something else something even more stable similarly the heaviest elements like uranium and polonium are actually unstable in fact they're so unstable that they fall to pieces naturally through radioactivity and here in the middle are the most stable atoms of all nickel cobalt and iron so far so good now here's the amazing bit this nucleus stability graph turned

out to be uncannily similar to a different graph altogether but it was a similarity that no one had ever suspected that's because data from this other graph came not from the tiny nucleus but from as different and arena as you can imagine the vast expanses of space this other graph came from astronomers who study the blazing light from stars and shows the abundances of the different types of atoms in the universe by far the most common atom of all is that of hydrogen followed closely by helium but not a great deal of anything else now

look at this it really is of cosmic significance both graphs a stability graph and the abundances graph show the same strange but very noticeable peak in exactly the same place the first scientist who spotted this were blown away one graph from the tiny nucleus and the other from the Vasus of space point to the same magical atom the atom that provided the key to unlocking the secrets of the entire universe also turned out to be one of the most abundant atoms in the entire universe amazingly that the properties of its nucleus seem to lead directly

to how much of it there is and it's not just through the line radium which is very unstable turns out to be incredibly rare an iminium which is relatively stable turned out to be relatively common it's a patent which appears right across the list of elements the signature of their nuclei is written in the skies greatest minds the first illusion was a rebel and a madman fred hoyle he loved removing the hills and dales of his native angel who spoke his mind even though it brought him into conflict with his peers he became something of

a scientific pariah all the life among other sciences he explored the strength over through the science of the atom and the science of the cosmos Hoyle realized what the graphs revealed is that the underlying fever [Music] everything in the universe is in a state of flux the atoms are trying to gain protons in an attempt to become more stable [Music] was to ask how and where in the cosmos all this atomic transformation all this alchemy takes place Hoyle knew that and stars like our Sun hydrogen turns into helium by a process called nuclear fusion but

could nuclear fusion also be the way [Music] Fred Hoyles great insights was to work out precisely how the heaviest elements are created through nuclear fusion Hoyle worked out that this process can only take place at unimaginably high pressures and temperatures of millions of degrees centigrade in our universe there's only one place where such conditions exist in stars Fred Hoyles problem was with the details to explain how fusion could create atoms heavier than helium was tricky and complicated Hoyle had to explain precisely how in the fierce heat inside stars light atoms might fuse to become heavier

lines in the forties Hoyle worked out that our Sun is hot enough to fuse atoms like oxygen carbon and nitrogen but what about heavier atoms like copper zinc or iron his calculations showed that they could be made inside stars but these would have to be much hotter than our Sun and he knew exactly where to find them these noted stars near the end of their lives we called red giants astronomers had discovered that there were hundreds of millions of these monsters throughout the universe Fred Hoyle reasoned that they all do not allow wait yet atoms

to be fused but there was still problem even the mighty red giants weren't hot enough to make the really heavy stuff atoms like gold and uranium to make these [Music] imaginable temperatures and pressures his only hope was that somewhere out there in the vastness of space with things so big and so hot they made our Sun look like a birthday candle and towards the end of the Second World War during a research trip to Southern California fred hoyle found them this is the hundred inch telescope at the Mount Wilson Observatory outside Los Angeles when it

was first built in 1917 it was without doubt the largest telescope in the world and it was while he was here he met up with the great astronomer Walter Barda who told him about supernovae now these are processes when massive stars explode with an incredible intensity and in a flash of inspiration Hoyle realized that here at last were the extreme conditions necessary to produce all the heavy elements what Barda was referring to was an explosion of simply cosmic scale when the largest stars run out of hydrogen to fuse into helium they come to the end

of their lives and they collapse under the weight of their own gravity and then explode outwards in a blinding flash of inspiration oil and his colleague William Fowler realized that super novae might be the hottest places in the universe hot enough to fuse together even the heaviest of atoms Horan and Fowler had found the furnaces in which everything was made the discovery of how atoms are made in stars is surely one of humanity's greatest achievements except for one glaring problem one that Hoyle could never explain away and it was this stellar nuclear fusion can explain

how all the elements in the universe are made except for two two very important ones the two simplest elements hydrogen and helium in the 1940s using increasingly accurate equipment scientists found that a quarter of the Sun was in fact helium which was considerably more than they thought they realized that diffused that amount of helium would mean the Sun would have to be burning at billions of degrees but the truth was the Sun only burns at 15 million degrees the Sun just wasn't hot enough to have made all that easy in fact it turns out that

per cubic meter the Sun actually generates less heat than a human being so I produce more heat than a piece of Sun the same size as me this means that the Sun is just not hot enough to make all the helium we know that it contains if all the helium wasn't made in the Sun then where did it come from and even more crucial was the question Hoyle was in denial about if all the atoms in the universe started off as hydrogen where did that come from all their hydrogen and all that helium needed an

explanation this problem catalyzed one of the most vicious fights in post-war science that's because it turned into a much bigger question in fact the ultimate question was the entire universe created in a single instance or has it always been there nearly every post-war physicist was sucked into this controversy the two men were at its center the other was an eccentric Ukrainian called George Gamal six-foot-four a practical joker and a refugee from Stalin's Russia another physicist said of Gamal even when he's wrong he's interesting both men would stake their careers on this mother of all physics

battles it all began innocently enough Gamal had recently been appointed a professor at George Washington University [Applause] this was George Gamow office at the George Washington University it's really pokey it was here that Gama worked on the problem of why there seemed to be too much helium gas in the Sun then could be accounted for from the fusion of hydrogen gandalf came up with the crazy idea that maybe most of this helium had been around before the Sun was even formed this is the moment it gets controversial and leads us in Nick's room leading to

rau creation for gamma to assert that helium existed in the universe before the Sun and the stars were formed he had to come up with another place that was capable of making here Gandalf knew wherever this process walks it needed to expect a searing beam can be set millions of times hotter than the Sun at this temperature matter as we know it is written hydrogen Digital Rights cosmic offense was reaching such a terrifying image to explain this he used a speculative theory that was doing the rounds at the time that suggested the whole universe had

been created in a single cataclysmic explosion billions of years ago a theory that today we call the Big Bang for decades astronomers have known that the galaxies are flying away from each other at astonishing speeds the universe is getting bigger this means that in the past the universe must have been much smaller and in the very very distant past the entire universe must have been a tiny almost infinitesimally minut dot and the implication of this is a single moment of creation an instance at which all matter even time and space came into being in 1945

most scientists were uncomfortable with this idea but not scallop he spotted that it might solve the mystery of the excess here in the silent stars gamma worked out that if the entire cosmos was squeezed down to a tiny dot it will be immensely hot in the first few minutes after the creation the universe would have been hot enough for hardened nuclei to squeeze together to make all the excess helium in the Sun and stars now after those first few minutes the universe would have expanded and would have been too cool but a few minutes were

all gamma off needed in that time all the hydrogen and almost all the helium was made that's about 98% of all the atoms in the universe today or as gamma put it our universe was cooked in less time than it takes to cook a dish of duck and roast potatoes but by arguing that the Big Bang a deeply controversial idea had created most of the hydrogen and helium in the universe Gamal ignited an enormous Rao of the creation Fred Hoyle soon became the most vocal of gammas critics Fred Hoyle hated the idea of the Big

Bang with every fiber of his being you see as a committed atheist he objected to the theory because a single moment of creation to him smacked of a divine creator gammaw hit back saying that without the Big Bang Hoyle couldn't properly explain why there was so much Hajin and helium in the universe both men had their supporters and the arguments between the rival camps became quite shrill and personal Hoyle was deemed as an old-fashioned crusty old brint by the big bang supporters and Gamal was condemned as a closeted creationist by Hoyle supporters the argument raged

in scientific conferences and in the popular press secretly each side knew that they had a compelling argument but both lacked the killer piece of evidence that would settle things decisively the conflict seemed destined to remained unresolved then south of New York close to the mean streets of New Jersey an unlikely piece of equipment was to make one of the most important discoveries of the century and settle the arguments once and for all [Music] this giant piece of sadly rusting machinery is the Bell Labs horn antenna in New Jersey it's in fact a radio telescope but

rather than looking like the more traditional satellite dish it has this huge horn like structure that could be rotated round to face the sky and pick up radio signals from space it's a bit like a giant hearing aid but it could pinpoint very very weak signals extremely accurately it was originally built for research into satellite communication but instead it was used in the mid 1960s to make one of the most important discoveries in the history of science to researchers Arno Penzias and Robert Wilson had got hold of this antenna in 1963 from Bell Laboratories with

the intention of doing research into the faint halo of hydrogen around the Milky Way before Penzias and Wilson could begin their experiment they had to make sure they got rid of all the background noise the antenna was picking up it's a bit like the hiss on radios in between stations they spent the best part of a year checking all the equipment and the electronics they even got down on their hands and knees inside the dish to scrub it clean of what they called white dielectric material which is basically pigeon crap but even after all this

there was still a faint persistent hissed they couldn't get rid of and it was there which ever direction the antenna pointed there is only one viable explanation the noise was the sound of radiation the afterglow of gamma ops beep here at last was final proof that Gama was right the Big Bang had to have happened you see soon after the universe was created about 300,000 years after the Big Bang it had expanded and cooled enough for the atoms of the lightest elements to form leaving the whole universe a wash with light now Georg gamma had

earlier predicted that this afterglow of creation with today be in the form of weak microwave radiation you can actually hear this radiation as a tiny fraction of the hits on your radio or TV between channels the detection of this cosmic background radiation by Penzias and Wilson showed that gamma offs Big Bang Theory was correct and that he was right about how hardin and helium were formed in the early universe so this together with Hoyle and Fowler's theories about how the atoms of all the heavier elements were cooked inside stars gave us the complete picture we

finally understood how the atoms of all the elements in the universe were made in less than 100 years science has before it a truly explained where we come from and was able to describe the entire 14 billion year history of the cosmos in the beginning is the Big Bang explosion in the following 10 minutes in the searing heat the nuclei of hydrogen [Music] [Music] separated out from each other as they did this they released light it's the remnants of this light his articles massive clouds of hydrogen coalesced into the first stars in here they began

to fuse producing star lights and eventually all the other types of atoms of existing our earth and everything on it including our own bodies was forged long ago in the crucibles of space for instance my body is almost three-quarters water which we know is made up of oxygen and hydrogen atoms we now understand that Harden was formed thirteen billion years ago soon after the Big Bang itself whereas oxygen had to wait to be cooked inside stars like our Sun the same is true of another important elements in my body carbon the elements on which all

life-forms on earth are based but my body also contains other elements in smaller amounts like iron this element was formed during the dying embers of gigantic stars as they ground towards the ends of their lives there are also trace elements like zinc there are only two grams of zinc in my body but this element had to be created during a supernova the explosion of a giant star with cosmic violence during which lighter atoms are fused together to form heavier elements the same is true for all naturally-occurring elements that are all cooked in cosmic cauldrons romantically

you could say that we're all made of Stardust but the truth is also that we're all just nuclear waste [Music]