Why Is Everything Made Of Atoms?

if in some cataclysm all of scientific knowledge were to be destroyed and only one sentence passed on to the next generation of creatures what statement would contain the most information in the fewest words I believe it is the atomic hypothesis or the atomic fact or whatever you wish to call it that all things are made of atoms [Music] 5. 4 3. 2 one the ship rattles as it stretches out into the void beginning the adventure of a lifetime the nervous crew were off on an epic journey to visit their home world's only natural satellite though similar in concept to the journey undertaken by the Apollo Astronauts when they left Earth for the moon this Voyage is very different when Armstrong and Aldrin headed for history on the lunar surface they needed only to travel a distance equal to the width of 30 Earths our Intrepid Travelers must cover a distance equal to more than 63 000 times the diameter of their home world compared to this crew's destination though the Moon is a Celestial snail it crawls around the earth once a month at a speed of 1000 meters per second that may sound fast but this satellite is whipping around at over 2 million meters per second or just under one percent of the speed of light it's moving so quickly that it complete 6.5 quadrillion orbits each and every second and for it is no moon and this is no solar system our Travelers are not exploring the astronomical Realm but the atomic one they a brave automotes a drift inside the hydrogen atom departing from the solitary proton at its Center they are in search of the lone electron that encircles it [Music] but their mission is even harder than it first appears for the electron only orbits the proton like a moon orbits a planet in the simplified Bohr model of the atom named after the Danish physicist Niels Bohr modern quantum physics say that we can never know for certain where the electron actually is we can only say where it's most likely to be the blur of all its possible paths creates a cloud around the nucleus our automods could therefore Never Land at their destination only float into fog of possibility [Music] today these bizarre atoms are the universe's Lego bricks vast galaxies swirl in the void and distant Stars keep vigil over the night but they are all built out of atoms as we all are indeed there's an entire Cosmos inside you the number of atoms in your body alone exceeds the total number of stars in the entire observable universe even if you started counting them at a rate of a billion a second it would still take you far longer than the current age of the universe to complete the task and as we have already seen even within the atoms themselves there are entire complex systems to explore and yet at the very beginning of time the number of atoms in the universe was precisely zero not a single atom in the entirety of the cosmos so how did we end up here where did the very first atom come from and just why is everything made of atoms [Music] the Earth weighs about 6.58 billion trillion tons and about 1.85 billion billion of that is carbon the climate can sometimes feel like an impossibly big problem for one person to try and solve and that is where Ren comes in our sponsor today Ren is a website where you can calculate your carbon footprint then offset it by funding a mix of carbon reduction projects like tree planting mineral weathering and rainforest protection by answering a few simple questions about your lifestyle you can find out your carbon footprint and how to reduce it and then you can actually offset what you have left over you also receive regular updates on what you support one particularly impressive project is biochar in California which prevents wildfires by removing dirt and flammable trees then turning the biomass into biochar thus stopping it from ending up in the atmosphere a cutting-edge way to tackle the climate so offset your carbon footprint on Ren the first hundred people who sign up using the link in the description will have 10 extra trees planted in their name thanks to Ren for supporting educational content on YouTube [Music] a wicked wind howls across the Black Sea waves swell and crash as the previously mirror smooth water is tossed and churned marooned on a kayak amid this Maelstrom is a pair of newlyweds they are refugees fleeing Ukraine to escape from the Russian regime yet this is not a 21st century Story the year is 1932 and the couple stranded in the tumult are the physicist George gamoff and his wife liuboff who he affectionately calls Roe after the Greek letter but what could have driven this young couple to risk their lives on such a perilous Journey the early 1930s witnessed a big shift in the way the Soviets treated their scientists and intellectual ideas and foreign trips were increasingly tightly policed gamoth wants to present his research at a large scientific conference in Rome but needs a new passport his application is constantly kicked into the long grass by bureaucrats in Leningrad who promised progress but instead deliberately run down the clock he never goes to the Italian Capital yet his endless visits to the passport office have one significant upside it is there that he meets Roe they marry soon after and within a year the newly words agree to flee they pour over Maps looking for the surest means of escape from the Soviet Union and so they settle on the Black Sea leaving gamof's birthplace of Odessa to head for turkey gamof still has a Danish motorcycle license from his days collaborating with the physicist Niels Bohr in Copenhagen and So the plan is to wash up on a Turkish Beach pretend to be Danish and asked to be taken to the Danish Embassy in Istanbul the journey couldn't have started better the water is calm and the breeze is gentle but when they awake Before Sunrise the second day the weather is already turning by the evening the situation intensifies and soon becomes perilous by the time the storm abates they are exhausted to the point of hallucination drifting alone on the Open Water Strong Winds buffet the boat all the way back to Crimea despite this setback eventually gamoth and Roe do Escape they secure passage to a scientific conference in Belgium and after the conference Mary Curie helps the couple extend their stay in Western Europe never to return to the Soviet Union they finally headed to the United States in early 1934. this entire Odyssey has unfolded before gamoth's 30th birthday six years later gamoff is granted American citizenship free from the shackles of Oppression he is now able to continue his work and it is this work that would turn out to be pivotal in our understanding of physics for it would change the way we think about the history of the universe forever [Music] in 1929 three years before gamoff's exploits on the Black Sea the American astronomer Edwin Hubble had shocked the astronomical establishment with evidence that the universe is expanding if the universe is growing day by day then it was smaller yesterday and smaller still a week ago keep rewinding the clock and there was a time when every part of the modern Universe was concentrated down into an incredibly small space before it expanded outwards the Big Bang except that it wasn't such a new idea to gam off the Russian physicist Alexander Friedman had already predicted the universe's expansion back in 1925 and the pair had had lengthy discussions about it during gamoff's time in Leningrad gamof was spending much of his early time in America working on something else the ultimate power source of stars yet the focus of his attention was shifting and in October of 1945 gamoth writes a letter to his old friend Niels Bohr to Mark the Dane's 60th birthday the letter reveals that gamoth was starting to apply his work on the internal mechanics of stars to the origin of Mata in the early Universe immediate immediately after the big bang up until this point cosmologists had assumed that the early Universe was dominated by Mata the staff that all visible structure is made from from stars and planets to galaxies and Galaxy clusters yet gamoth began to suspect otherwise history waivers on who truly deserved the credit but it could have been gamof's student Ralph Alpha in his doctoral dissertation Alpha claimed that the early Universe wasn't dominated by Mata but by electromagnetic radiation this electromagnetic radiation would supposedly dominate the early Universe for a full 50 000 years after the big bang physicists have another word for electromagnetic radiation light we may use that word for the light our eyes can see but there's more to it than that just as there are frequencies of sound too low or too high for our ears to hear there are frequencies of light too low or too high for us to see when a physicist uses the word light they mean the radiation that spans the full range of these frequencies from gamma rays and x-rays at the high frequency end to microwaves and radio waves at the other when you use a microwave to heat your dinner you're actually cooking the food using low frequency light and so light and matter were trapped together in this nascent Universe after a hundred thousand seconds of expansion the entire universe was still denser than the air you're breathing right now and continued for thousands of years to be dense enough for sound waves to travel through sound waves of such low frequency that they'd need to be squashed 100 septillion times that's one followed by 26 zeros just push them into the range of human hearing something that in 2013 John G Kramer at Washington University used data from the early Universe to reproduce [Music] cosmologists call these sound waves baryon acoustic oscillations and they can still be detected today using facilities such as the Sloan digital Sky survey as the universe kept expanding it continued to stretch out these sound waves shifting them to ever lower frequencies but then came a point when everything changed it is one of the most important events in the entire history of the universe and it was predicted by none other than Alpha and gamoth it is called recombination and it also opened the floodgates for the very first light to come streaming out into the early universe but what we combined exactly and what does this first light have to do with the first atom the feeling of claustrophobia Rises by the second you're trapped whichever way you turn just leads to a blocked path have you seen these walls before did you turn left or right at this Junction earlier no matter how hard you try you just can't figure out how to escape and that is not surprising because there is no Escape you are trapped in an impenetrable maze this series of never-ending dead ends is exactly what light encountered after the big bang everywhere light tried to go it bumped into insurmountable obstacles in the form of subatomic particles and yet the universe didn't begin such a labyrinth in the very beginning there was none of this matter to get in the way for the faintest sliver of a second just after its birth it was free however very quickly light turned into its own captor snapping the shackles shut on itself this happened because light leads a double life like the vampires and werewolves of myth and folklore it can shapeshift into something else Mata light is a form of energy and energy and matter are two sides of the same Cosmic coin and the more energetic the light the higher the likelihood that it will change into matter and So within a trillionth of a second after the big bang some of the universe's energy is converted into particles of matter that start popping into existence flooding the universe with fundamental particles everything needed to build atoms including electrons yet we'll still have to wait hundreds of thousands of years for these particles to actually coalesce into the first atom we may already have electrons but to make a hydrogen atom like the one explored by our automonauts we also need a proton unlike electrons they are built out of something else quarks fundamental particles that also appeared during light's partial metamorphosis into matter quarks come in a menu of different flavors but the most important ones for our story of atom formation are the up Quark at the down Quark up quarks carry a positive charge and down quarks a negative charge a proton is made of two up quarks and one down Quark giving a proton an overall positive charge yet these quarks are not natural bedfellows electric charges act like the poles of a magnet Opposites Attract but like charges repel one another and so how can two positively charged up quarks happily sit side by side inside a proton the solution to this puzzle lies with forces the glue needed to stick the first atom together physicists know of four fundamental forces in the universe two are familiar to us gravity and electromagnetism light is an electromagnetic wave and it is electromagnetism that repels the magnets and quarks from one another but down in the atomic world two less familiar forces are a play the weak nuclear force governs radioactivity but it's the strong nuclear force that really dominates here it is one Duo decillion times stronger than gravity that's 10 followed by 38 zeros significantly more zeros than there are stars in the entire observable universe the strong nuclear force is also 100 times stronger than the electromagnetic force so two quarks with the same charge may want to push away from one another but the strong nuclear force can override this electromagnetic Instinct and keep them tight together there is a catch though the strong nuclear force may be the king of the forces but the kingdom it governs is Tiny it only has dominion over the most minute of distances about a trillionth of a millimeter initially energies are too high for quarks to bind together through the strong force when the quarks first formed the temperature of the universe was over one quadrillion degrees though they pass very close to each other the quarks collide with such high energy that they cannot stick but this new universe is expanding all the time it cools as it grows and particles within it slowed down after the first millionth of a second the temperature drops to a mere one trillion degrees and the first protons are able to form neutrons formed too the other kind of particle you'll find in an atomic nucleus they are made up of one up quark and two down quarks simple enough you might think but again as with Boar's model of the atom neutrons and protons are not quite that straightforward [Music] indeed the more physicists learn about the proton the more downright weird it gets to quote Mike Williams physicist at the Massachusetts Institute of Technology this is the most complicated thing that you could possibly imagine for one thing together the three quarks known as valence quarks actually make up just one percent of the protons Mass the rest is taken up by particles called gluons they are the particles that carry the strong nuclear force and it's by exchanging gluons that the trio of valence quarks are able to bind together into a proton yet it gets a lot stranger occasionally gluons pick up enough energy that they can do some shape-shifting of their own turning into a quark and its antimatter equivalent the anti-cork these so-called sea quarks then quickly recombine back into a gluon so at any one time a proton is really a blur of valence quarks gluons and sea quarks we still don't understand all the details and experiments like the relativistic heavy ion collider in New York a helping physicists probe deeper what we do know is the gluons and sea quarks make up 99 percent of the proton's mass because they aren't permanent physicists refer to the Sea quarks as virtual particles this means that the mass of the proton the particle you'll find at the center of every atom in the universe mostly comes from an Infinity of sea quarks that don't actually exist from top to bottom strange to charm a whole range of quarks can be found as sequarks popping in and out of existence for just short enough periods to not break conservation of energy a recent experiment at the University of Milan has even shown that sometimes charm quarks actually appear at lower energies and most bizarrely of all charm corks have almost one and a half times the mass of the entire proton the low probability of them appearing meaning that their full Mass isn't added to the proton itself the quantum world of the very small is a counter-intuitive place [Music] foreign returning to the universe's timeline now that we have protons and neutrons the next step on our journey to the first atom comes as the universe continues to cool and expand meaning the protons and neutrons lose speed and it is here the George gamoth re-enters our story in 1948 he has a letter published in the scientific journal physical review letters it runs to no more than a page but its length belies the magnitude of its insights the papers addressed that within a handful of minutes of the Big Bang the universe cooled to a billion degrees enough to allow the strong nuclear force to stick a proton to a neutron this proton neutron pair is known as a deuteron and it's the gateway to a whole new way of building structure in the infant Universe stars like the sun generate vast amounts of Light by churning hydrogen into helium through a process called nuclear fusion slightly less helium comes out than the amount of hydrogen that goes in and the difference is converted into Sunshine as mass turns back into energy along with Ralph Alpha gamoth was the first to figure out the series of steps by which Fusion turns hydrogen helium and deuterons played a crucial role for when a deuteron combines with a proton it makes the nucleus of a helium-3 atom then when two helium-3 nuclei fuse they make the nucleus of a helium-4 atom and two extra neutrons in the modern Universe these reactions can only unfold in places with extremes of temperature and pressure like the cause of stars but similar temperatures were present Universe wide soon after the big bang though not for long there was only an incredibly short window of opportunity for Fusion to take place the temperature had to be cool enough for deuterons to form in the first place but still hot enough to fuse everything else together and that window opened less than a second after the big bang and slammed shut about 20 minutes later when the temperature of the universe cooled a roughly 20 minute period in which about a quarter of the universe's mass of hydrogen nuclei turned into helium nuclei and so we have a universe that's still just 20 minutes old sprinkled with 12 hydrogen nuclei for every one helium nucleus and a billion particles of light for every nucleus impressive progress for just over a quarter of an hour but we still didn't have the first atom for that we need to bind electrons in orbit around these nuclei and that would take a very long time indeed electrons are negatively charged and protons make Atomic nuclei positively charged Opposites Attract and so the electromagnetic force can snare a passing electron and trap it in orbit around the nucleus with the electromagnetic force is 100 times weaker than the strong nuclear force so the universe has to cool all the way down to Just 4 000 degrees in order for the particles to slow down enough for the electromagnetic force to do its thing this will take 380 000 years of expansion and only then finally the first atom forms but as with the bizarre components of its nucleus adding electrons certainly doesn't make things any less complicated electrons were discovered towards the end of the 19th century yet time has only burnished their Enigma and almost 2 000 times lighter than a proton an electron is generally thought to be a single point with no shape or internal structure truly fundamental like quarks they don't orbit the nucleus-like planets around the Sun either quantum physics tells us that it is impossible to know both the position and speed of an electron with perfect accuracy at any one time an electron isn't just in one spot around the nucleus it's simultaneously occupies every possible spot one single electron envelops the nucleus like a fog and we can only talk about where it is most likely to be electrons as with all other fundamental particles also have a curious property called spin they are deflected by magnetic fields as if they were rotating balls of charge but this rotation is counter-intuitive if you spin around 360 degree Series in other words rotate through a full circle then you'd return to where you'd started you're a spin 1 entity but electrons a spin half entities they have to be rotated 720 degrees to return to where they started except that electrons aren't actually spinning at all quantum physics forbids it though it is useful to think about them as spinning they can't be and so everywhere we look the inside of an atom is like a giant hole of mirrors deception illusion and subterfuge accompany each of our endeavors to understand it a bizarre Quantum realm that runs counter to Common Sense wrapped up in Mysteries that we are very far from unraveling but what we do know is that the formation of the first atoms some 380 000 years after the big bang set light free photons of light now have a way out of the previously impenetrable maze that they had inflicted upon themselves with electrons suddenly sucked into orbits around Atomic nuclei there is an Abrupt increase in the space between matter light can travel without whacking into anything and off it goes a 299 million 792 458 meters per second in 1948 Ralph Alpha and Robert Hermann built on this work and predicted that this first light to flood out into the universe hundreds of Millennia after the big bang should still be visible today and finding it would be the equivalent of a Smoking Gun a hard to argue with proof that the Universe really did begin with a hot big bang unfortunately no one took much notice and the idea was largely forgotten for a decade and a half until foreign [Music] Robert Dickey stands on the roof of the radiation laboratory at the Massachusetts Institute of Technology holding a device of his own making Aloft Dickey joined MIT under a cloak of secrecy in September 1941 having only just completed his PhD at the age of 25. the second world war has been raging for two years and although the United States remains neutral it is starting to make preparations for joining The Fray they were right to within weeks of Dickies starting at MIT the Japanese attacked Pearl Harbor and the United States enters the war the very next day Dicky is a keen inventor with a real skill for electronics it's in the blood his father was a patent attorney and Dickie Jr would go on to file over 50 patents in his lifetime for devices from clothes dryers to lasers but at MIT Dickie is working on radar the term radar an acronym for radio detection and ranging was coined by the US Navy just years before by sending out short pulses of radio waves you can detect objects like enemy aircraft when they reflect those radio waves back to you except that radar was initially a pretty blunt instrument radio waves are a form of light part of the electromagnetic spectrum they have the longest wavelength of any light the distance over which the wave repeats itself radar has been around since the 1930s but Dicky is working on a big Improvement using microwaves instead microwaves have a shorter wavelength than radio waves meaning your radar picture will show greater detail Dicky invents a new receiver to pick up these reflected microwaves now called the Dickie radiometer yet the Curious child within him can't help but look even further up beyond the bombers and the dogfighters to space he wonders were there any microwaves are coming from the cosmos and so here he is on the roof of the radiation laboratory of MIT pointing his radiometer to the sky it's an idea he would return to over a decade later at Princeton as part of one of the most important insights in 20th century cosmology ultimately it would validate our story of the origin of the very first atoms as with many of us Dickey found the idea of the big bang a little conceptually troubling how can something come from nothing is perhaps the most asked question about the universe's origin so Dicky explores the idea of cyclical universes and expanding universe that slows stops and shrinks collapsing back in on itself in a big crunch only to explode outwards again in another big bang a collapsing Universe would get exceptionally hot as Mata crushed down on itself electrons would get ripped away from protons as the universe returned to a sea of subatomic shrapnel Dickey dubs this Mega hot Maelstrom a fireball the ensuing bounce and expansion would cool the fireball back down and allow atoms to reform and this is where the name recombination originates in this Theory the atoms truly would recombine by thinking this scenario through Dicky like gamoth over a decade earlier hits upon the notion that there should be some Relic radiation left over from this super hot stage and that it would still be visible today he calls it Fireball radiation and it's the same radiation from recombination that gamoff and his colleagues predicted back in 1948 although Dicky is initially unaware of their work Dicky reasons that this Fireball radiation should now be in the microwave part of the electromagnetic spectrum the very part he has spent two decades working on of course initially the leftover light from The Big Bang would have been in the visible part of the spectrum had anyone been around to see it it would have glowed yellow orange but the universe has continued to expand ever since the light was released 13.8 billion years ago that expansion has stretched the space between everything also redshifting any waves of electromagnetic radiation traveling through that space Dicky calculates that this Fireball radiation would have been stretched right out through the infrared and into the microwave spectrum and so he resolves to find it with his eponymous radiometer and begins to plan an observation run that would start in the mid-1960s but something strange happens before he has a chance to finish his work 45 minutes drive away in Holmdel New Jersey two radio astronomers are attempting a different kind of experiment their names are Arno penzius and Robert Wilson like gamoth before him penzius fled European totalitarianism a child evacuee from Nazi Germany penzias and Wilson are using the giant 6-meter Homedale horn antenna part of Bell Telephone Laboratories to listen out for radio waves reflected off orbiting satellites the signals they are looking for are very faint to hear them they must first get rid of any other interference they eliminate local radar and radio transmission and even remove interference from the receiver Itself by cooling it to minus 269 degrees Celsius using the liquid helium yet despite their best efforts there remains an annoying hiss in the detector like the static between channels on an old radio where could it be coming from it seems to be coming from all over the sky and it is then they spot what must be the culprit panzius and Wilson discover pigeons roosting in the antenna the heat from their droppings what they would later call a white dielectric material must be creating the noise the pigeons are carefully trapped and sent to the town of Whippany 30 miles away only for them to fly right back in the end they sadly meet their demise penzius and Wilson meticulously clean out their droppings but the hissing remains in all penzius and Wilson spent over a year trying to figure out the source of this maddening interference desperate pansia starts phoning around asking others if they have any idea what's going on Dickie is in his office in the middle of a meeting about building his device to look for Fireball radiation as soon as he hears what penzias has to say his heart sinks and he says to his colleagues well boys we've been scooped penzius and Wilson pick up the 1978 Nobel Prize in physics for their Serendipity and Dicky is left empty-handed gamoth would never win a Nobel either and so ends the story of the discovery of the cosmic microwave background the unmistakable fingerprint of the formation of the first atoms undeniable proof that our universe started with a hot big bang as the earliest light dispatched into the universe it is an image of an infant Cosmos if our present Universe were a 40 year old human the cosmic microwave background is the equivalent of a photograph taken when it was less than 10 hours old hidden within it to Clues to the universe's future our present small temperature variations signal the existence of tiny differences in density in the infant Universe the more matter that falls into these densities the bigger they get and in turn the more matter that falls in within a few hundred million years the first galaxies will form as Mata relentlessly clumps together and along with this marked across this map of the cosmos now stretched to almost 500 million light years in diameter are the imprints of the sound waves of the early Universe the remains of the baryon acoustic oscillations experiments such as the dark energy survey high up in the Chilean Andes have mapped the layout of the modern universe like never before vast super clusters of galaxies stretch out among equally gigantic supervoids which mirror the tiny temperature variations seen in the cosmic microwave background the seeds of the universe's structure were sewn long ago but you don't need a giant horn antenna to tune into the universe's youth in fact an old analog television set will suffice in our modern digital age memories are fading of the snow that would settle across the screen as you twiddled between channels one percent of that static is the cosmic microwave background the universe began almost 14 billion years ago but the formation of the first atom was such a Monumental moment in its history that Echoes of the event remain our invisible companions throughout our lives and will take trillions of years of expansion yet to be stretched out beyond our view and so you may be forgiven for thinking that the rise of the atom was inevitable the final destination of any hot dense soup of particles as fundamental to reality as the constituent parts but that is certainly not the case in fact it is quite the opposite [Music] with a blindfold covering your eyes your other senses are heightened you hear every click and snap as the guns are loaded all two dozen of them you are about to be executed by firing squad the soldiers raised their weapons and aimed the barrels squarely at your chest this is it you think and your body braces for its last breath then every single bullet misses the Canadian philosopher and author John Leslie asks us to imagine a version of this scenario in his 1989 book universes how unlikely it seems that you're still alive it only needed one shot to hit its Target and yet every single gunman missed you owe your existence to an incredibly precise and improbable sequence of events any deviation from it and you simply wouldn't be here the story of our universe and of its atoms is a similar tale since its birth 13.8 billion years ago the universe has gone from having no atoms at all to being full of more atoms than we could possibly count in trillions of lifetimes the atom is so ubiquitous that we take it for granted atoms after all are everywhere and yet the atom is a ludicrously unlikely entity like your life in that courtyard it Teeters on a tightrope so fine that any minuscule misstep would see it snuffed out in an instant instant mess with the physics even slightly and every trace of chemistry and biology would fade away imagine that you could operate the universe using a giant control panel littered with knobs dials and switches each one responsible for some key property of existence the masses of certain subatomic particles the strength of the various forces in this scenario it wouldn't take much tinkering to destroy atoms entirely for an atom to be stable the orbits of its electrons need to be a lot bigger than the size of the nucleus otherwise the electrons risk crashing down on the automotive's Homeworld of the proton like a satellite dragged back to Earth in fire and fury you'd only have to make the electromagnetic force a little bit stronger and electrons would be pulled in tighter weaken it and electrons could fly off on their own like stars flung out from a distant Galaxy rendering them forever out of our autonomous reach or you could weaken the strong nuclear force then protons and neutrons wouldn't hug each other so tightly increasing the size of the nucleus and hastening the electrons demise a physicist would say that these forces appear finely tuned the dials have to be in pretty exact locations otherwise atoms wouldn't exist and one of the first people to discuss this so-called fine-tuning in detail none other than Robert Dickey back in 1961 electron orbits are far from the only aspect of the atom that appear finely tuned the neutron for example is a mere whisker heavier than the proton by about one-seventh of one percent physicists know this thanks to increasingly precise experiments indeed in 2021 a pair of researchers from Florida State University measured the deuteron to proton Mass ratio to an accuracy of 4.5 Parts in a trillion this small difference in Mass between the proton and the neutron is greater than the mass of the electron and this is key where the electron heavier than the difference in Mass between its two bulkier cousins it could be captured by a proton and turned into a neutron in other words you can't change the masses of electrons protons or neutrons by much either or again atoms simply wouldn't exist fiddle with the control panel further and you can cause more Mayhem the reason the neutron is heavier than the proton is due to differences in the masses of their quarks as we saw earlier a proton is made of two up quarks and one down Quark two downs and one up form a neutron the down cork is ever so slightly more massive than the up Quark so a neutron is heavier than a proton yet these masses appear finely tuned as well if the difference in Mass between up and down Quark were larger the entire history of the universe would have been radically different a downcore could be able to Decay into an up Quark if that happened inside a neutron suddenly the neutron would become a proton the deuteron the key marriage of a proton to a neutron would be a nulled this means no Fusion after the big bang and a universe that only contains atoms of hydrogen none of the 117 other types of atom or elements in the periodic table would exist no oxygen for you to breathe or iron to carry that oxygen around your body changing the mass of the quarks isn't the only way to Snuff out the deuterons they only exist because the strong nuclear force combined a proton to a neutron in the first place make that Force just nine percent weaker and it would be too puny to hold deuterons together going the other way ratcheting up the strong force by Just 2 two percent would have even more profound consequences it would then be strong enough to bind two protons together a form of hydrogen called a diproton we've never seen one in the real universe and there have only been tantalizing and unconfirmed reports of one inside experiments such as the radioactive isotope beam Factory in Japan had they existed after the big bang they would have rapidly fused into helium and all hydrogen would have quickly disappeared from the universe we live in a helium-dominated universe instead of a hydrogen-dominated one and so whichever dial switch or Knob we contemplate on the great control panel of the universe it is surprisingly easy to eradicate atoms in other words all the settings appear to be in exactly the right place to permit atoms and the things that they are built from it seems quite the coincidence it is as baffling to physicists as your survival in front of the firing squad and so scientists and philosophers have put forward three broad ideas to explain the fine-tuning problem first of all maybe it's just dumb luck after all the settings all have to be somewhere and although almost impossible they could have fallen in the right place so as to give rise to the first atom some 380 000 years after the big bang by one account the odds of this are about 1 in 65 billion trillion that's roughly the same odds as you selecting the sun when asked to choose randomly from a bag containing all the stars in the observable universe many find these odds too extreme to accept and see this apparent fine tuning is evidence of something or someone with a steady hand on the tiller in other words not being an accident but the deliberate Act of manually setting the dials to the right place this could be some omnipotent deity or a bored Advanced civilization who wants to create their own real-life version of The Sims there is another option though thanks to strands of evidence like the cosmic microwave background cosmologists are confident that the Universe began with something like a big bang but what banged exactly when trying to answer that question a tantalizing possibility emerges the Big Bang is a good theory but not a perfect one and some scientists believe the cracks can be papered over and the theory salvaged if there was more than one bang perhaps an Infinity of banks each one giving rise to a new universe the settings on the control panel of each Universe could therefore vary depending on the exact way the universe emerged from the cacophony and all possible settings would be found across this endlessly large Multiverse so which of these universes are you going to find yourself in you can't be in ones in which the dials are set so as not to permit atoms and in turn the stars and planets made from them you a giant lump of atoms can only find yourself in a universe where the strengths of the fundamental forces and the masses of the subatomic particles allow atoms to form and what a journey those unlikely atoms have been on the constituent Parts forming within minutes of the Big Bang to coalesce at recombination before hurtling across space spinning into stars exploding back into space pulled into planets and eventually ending up inside a brain capable of contemplating its place in this vast and intricate universe [Music] you've been watching the entire history of the universe don't forget to like And subscribe and leave a comment to tell us what you think thanks for watching and we'll see you next time [Music]

Channel: History of the Universe

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Id: ae36scLdCsE

Length: 45min 41sec (2741 seconds)

Published: Wed Dec 21 2022