Exploring Big Bang Misconceptions and Theories

the Big Bang did not bang it did not explode it was not a bomb it was not a detonation or a conflagration there was no blast no debris no shrapnel the universe was simply smaller in the past and it will be bigger in the future and that is not the only misconception you may have about the Big Bang to begin with the big bang didn't happen anywhere it happened everywhere it was not an event in space but rather an event in time it was the tick on a clock not the notch in a ruler it occurred in the finite past of everything in the cosmos every atom every particle every Point can trace its evolutionary origins back through the eons to the Big Bang the Big Bang happened in the room you're in right now it happened in the Andromeda galaxy it happened inside you it happened within the entire expanse of the known and unknown universe the entire universe was smaller hotter and denser in the past now it's not that is the great lesson of the big [Music] bang and so the universe has no Center and no Edge it expands from nowhere and expands to Nowhere the universe did not originate from a single point in Space the Big Bang was a point from which space originated it in these statements lies an inconsistency a paradox 13.78 7 billion years ago our theories tell us that the Universe the entire universe regardless of its size even if infinite was contained somehow in a singularity a point of infinite density and no spatial extent but this makes no sense this does not obey the rules of reason or logic and this is because the Big Bang Singularity is not a true representation of what everything was it is simply a heavy hint that our equations our maths our physics is dysfunctional The Singularity is a sign that we do not understand our Origins the earliest moments of the Big Bang but in the darkness of that uncertainty is nurtured the seed of a new Awakening for in our ignorance of the Big Bang we have the opportunity for now only seen as the ghosts and Whispers of mercilessly complicated mathematics to pierce the veil of our own beginning to try and deduce what came before the birth of everything because at one time there was no universe and then there was this is the mystery of creation the Paradox of our reality revealed by the existence of the expansion of the universe but was that beginning truly the beginning did Time start with the big bang did our universe come into existence only at that moment or was there something before either similar to our Cosmos or entirely different if the Big Bang was the beginning of everything that we know was it also the beginning of literally everything or is our universe just a small part of a grander fabric greater story that has been told since the distant ages of time past and will continue to exist well after our Cosmos has sunk into cold [Music] Oblivion in 2022 incredible results started to arrive from the new James web Space Telescope but rumors online and in the Press started to spread that they were a death Nowell for The Big Bang Theory of course this was not the case and served as a great example of the importance of media literacy which is why I'm excited to have ground news kindly sponsor this video ground news Aggregates the world's news in one place so you can compare coverage and verify your information and it's been a big help in my research for example last month solar storms were reported to disrupt communication and produce Northern Lights as far as the southern us on ground news I was able to access over 200 articles published on on this at a glance nearly 90% were from sources rated highly factual indicating coverage is less subjective which is important for science news comparing coverage is also interesting NPR suggested the storms disrupted Communications while the majority of the sources including f.org emphasized the northern lights and no serious problems and so if you're looking for a better way to get the full picture I encourage you to visit ground. news/ subscribe through my link to save 40% off unlimited access and by subscribing you're not only supporting the channel but transparency in the media as well it was 2013 and it was time to party the attendees gathered in the main hall of the Paris Observatory a ground building situated on the south side of Paris near the old gates to the city people got up to speak to congratulate each other on the successful Mission and a job well done including some remarks that there was of course more work to be done in the coming months but before anyone could dwell too much on the tasks ahead they marveled as cases were brought out from a back room the cases were full of champagne but not just any champagne the organizers of the party had commissioned a special bottling and the bottles had custom labels on each bottle was printed an oval disc with an odd speckled pattern that pattern was the cosmic microwave background or CMB a background radiation from just after the big bang that fills the entire universe the European space agency's plank satellite had collected the data to construct that image the highest resolution all Sky image of the CMB ever made the party goers was celebrating the first public release of the plank satellite data and they had every reason to celebrate the data taken by plank had confirmed the existing cosmological model and the story of The Big Bang and on top of this it had found evidence that the theory of inflation a hypothetical event where the very early Universe grew exponentially larger in a short amount of time was on the right track the Big Bang wasn't really a big bang what we call the big bang a name coined somewhat derisively by astronomer Fred Hy is really just a generic description of the model of the universe where our Cosmos used to be smaller in the past and will be larger in the future in this model there really isn't an explosive event that launches the creation of the universe or a swift unfolding of space that gives rise to everything we know instead it's much simpler it is just a mere EXP expansion from a smaller state to a bigger one and from that theory we can assign a number 13787 with an uncertainty of 0.02 a simple number but this number is special it's our current best estimate in billions of years of the age of the universe indeed a direct consequence of The Big Bang Theory is that there was a time before time there was a moment when the universe simply became and that moment existed 13.78 7 billion years ago but that's only the dimension of time as far as we know the three dimensions of space that also make up our universe could be infinitely big yes there is a limit to our observable Cosmos a boundary set by the finiteness of the speed of light that limit sits about 45 billion light years away beyond that we presume that there is more Universe more stars and galaxies and gas and dust but we don't know it could be infinite but not in the direction of time our universe could live infinitely into the future even when our Cosmos expands so far and so much that all the stars die out and existence is nothing more than a thin soup of particles near a temperature of abs absolute zero the universe will still exist time will still march forward directions in space will still be in place but the past is different there is a limit to what we perceive a boundary of our understanding even if the universe is infinitely big and will extend forever into the future it all came from something [Music] this simple straightforward Big Bang model has been able to explain a wealth of observational data like the apparent recession of galaxies away from us the appearance of the cosmic microwave background even the amount of Light Elements in the cosmos in fact no other cosmological theory is able to explain the existence of all those facts but just like any other scientific theory or model the Big Bang also has its shortcomings and in 1979 physicist Alan Guth was poking at one of those shortcomings in most theoretical models of the extremely early Universe at the time the cosmos seemed to naturally produce a significant number of defects things like magnetic monopoles cosmic strings and other bizarre Intergalactic warpings of space and time however none of these audities had ever been observed in the real the universe and so goth was trying to find a way to get rid of them in a stroke of Pure Imagination he wondered if the Big Bang really was a little more like its namesake than we' previously suspected a little Banger and so he proposed a new entity to inhabit the cosmos something called a Scala field scaler Fields were not a new idea in physics quantum field Theory which alongside Einstein's general theory of relativity underlies our understanding of reality is strange everything that exists every particle and every form of radiation is really the manifestation of an underlying Quantum field that fills the universe these Quantum Fields soak space and time the same way that olive oil and vinegar soak a piece of bread every particle has its own Associated field one for the photo known as the electromagnetic field one of the electrons known as the direct field and so on and so on when one of these Quantum Fields has a local excitation a region of higher energy vibrations we see that as an independent particle but of course even when a patch of the universe contains no particles the field is still there scal of fields are the simplest kinds of fields to exist they just have a single value a magnitude associated with every every point in SpaceTime every time you see a weather forecast with a map of temperatures across your local region you are looking at a Scala field a single number in this case a temperature associated with every point on the map the eminent physicist Peter higs had already introduced the language of scaler Fields decades before gooth when he proposed what is now called the higs field a scaler field working in the background of SpaceTime that is responsible for Mass but now it was goo's turn to invent a new scaler field that radically altered the Dynamics of SpaceTime in the distant past this scaler field would permeate all of space and time simply existing in the early Universe then randomly and suddenly this scaler field would experience a dramatic phase transition collapsing itself into a lower energy State this collapse would provide the energy necessary to make the infant Universe much much bigger in a very short amount of time indeed Guth estimated that if the universe inflated by at least a factor of 10 to the power of 50 or so in less than a second then all of those Troublesome defects would simply be scattered to the four corners of the cosmos while outside are observable limits and as well as this the process of a rapid inflation event would solve two other challenges to the traditional Big Bang model it would explain why why the universe could have a uniform temperature despite its enormous size because prior to inflation the cosos homogenized and why it appeared so flat if you take any geometry you want and make it really really big then it will always appear flat to any local observers just like the Earth appears flat in your garden and so because this idea of inflation so neatly explains several features of the observed Universe cosmologists began taking it seriously and within a few years guth's origin idea evolved in the modern conception of inflation first proposed independently by Andre lindai and the team of Andreas albrech and Paul steinhardt the quantum field didn't just suddenly jump to a new state but instead slowly evolved into a lower energy state it is this slow roll inflation that allows the theory to put the bang in the Big Bang at first the inflation Quantum field evolves into a lower energy State and Powers the act of inflation but at the end of this inflation when the field is exhausted the universe is large cold and empty but this is where the magic of slow roll inflation comes in through a process called reheating at the end of inflation the quantum field doesn't just sit still in its lowest energy State just like a ball that's rolled down down a hill the field wobbles a little this wobbling transfers even more energy back into the cosmos not in the form of super rapid accelerated expansion but in the creation of particles in quantum theory this is allowed Quantum Fields transform and intermingle all the time so in its dying breath the quantum field responsible for inflation decays away filling the universe with all the particles of everyday existence the electrons the photons the neutrinos and quarks even the dark matter and so if there's anything that fits the popular conception of the Big Bang inflation is it prior to this event the universe was small hot and dense when it was less than the tiniest fraction of a second old however inflation switched on in another tiniest fraction of a second the cosmos exploded in size and at the end of that stupendous expansion the universe relit itself suffused with energy from the inflation field spawning the particles that continue to inhabit the modern-day universe but while this model can handly explain many cosmological Mysteries that's not quite enough for it to rank as a true scientific theory at the same level of prestige as say general relativity or The Germ theory of disease most importantly when it comes to inflation we have more questions than answers we do not know the identity of the quantum field that drove it for even if it survives to the present day it would be just as a broken shadow of its former self sitting well beyond our ability to detect it we also don't know why inflation lasted as long as it did or why it had just the right Evolution to power super rapid expansion then Decay away flooding the cosmos with particles some cosmologist argue that due to these deficiencies inflation is not a sound scientific theory but the general concept of inflation that a Quantum field slowly evolved and triggered rapid expansion followed by a flood of particles does make some generic predictions that are testable and in fact have been tested the act of inflation didn't just rapidly expand the universe it rapidly expanded all the tiny quantum foam that inhabits SpaceTime that quantum foam is sub microscopic existing at the lowest level of reality the incredible expansion of the cosmos under inflation turned that foam into still very small variations but definitely bigger than they were and this formed the seeds of structure tiny variations in SpaceTime led to gravitational differences from place to place place and over time these differences grew eventually becoming the grandest structures in the universe generic theories of inflation regardless of the precise mechanics of the model predict very particular statistical properties of structure in the universe that we observe and the cleanest way to measure those structures is through mapping the cosmic microwave background the leftover light from when the universe was only 380,000 years old one major test of inflation involves something called the Scala spectral index the map of the cosmic microwave background contains many variations blotches of various sizes representing colder and hotter parts of the cosmos cosmologists can turn this map into a spectrum measuring how many large fluctuations there are how many medium and how many small a scaler index of one would tell us that every size of fluctuation adds the same contribution to the general pattern inflation models generally predict a scaler index slightly less than one and in 2013 the plank missions measured this number to be .96 to an accuracy of 5 Sigma the plank satellite measured the exact statistical properties predicted by inflation certainly a champagne worthy event and so even though inflation sits Beyond the Edge of known physics involving properties and forces and Fields that we do not yet comprehend most cosmologists believe that something like inflation happened in the early Universe while there are other hypothetical alternatives to the inflation story in the end they all tend to operate in much the same way a rapid expansion of space a flooding of particles and the planting of the first seeds of structure so even if in infation turns out to be an incorrect theory of nature by all available evidence the universe underwent something extraordinary in its earliest moments something that gave rise to the Big [Music] Bang but if inflation is correct if there was some exotic Quantum field that drove a super rapid expansion of space and ignited the Big Bang then the theory has some intriguing implications because before the Big Bang there was inflation and before inflation there was a NeverEnding stream of inflation in this view powered by Cutting Edge theoretical physics what we think of as our universe is just one in an infinite chain of universes each one bubbling and branching off of a stream that will continue forever inflation always was and always will be if this theory is correct then what came before the Big B hang before our universe was the [Music] Multiverse in Fodor Doo's 1846 novel The Double A Petersburg poem a struggling young bureaucrat finds an unlikely companion a man who looks exactly like him except more fearful at first the two men are friends but then the Double's Charisma starts to take over the original's life in the end the original finds many copies of himself and is forced into an asylum and though this is a fictional story the concept behind it is not as farfetched as it might seem because somewhere in a galaxy far far away there could be a copy a copy of you wearing the same clothes as you the same age as you the same life experiences lovers relatives as you the same favorite restaurant and hated sports team that copy of you who also goes by the exact same name as you could be watching a copy of this video right now in parallel the two of you watching it on exact duplicates of the screen at the same point in the video hearing the exact same information with the same voice this copy would be inhabiting another universe and this universe would be extremely distant from ours far far beyond the observable bounds of our Cosmos we could never access it never travel there and never exchange information with it but it could exist an exact replica down to the subatomic level and that copy would not be alone somewhere even more distant than the nearest copy would be another one and another and another in fact there would be an Infinity of use all watching this same video in this precise moment this is the reality of an infinite Multiverse a cosmos big enough to contain an Infinity of universes so large that it encompasses every possibility every combination of molecule and atom and subatomic particle and it copies each and every possibility an infinite number of times both in the present and extending far into the future the concept of a Multiverse is staggering in its scope but its tantalizing possibility is born in the fires before the Big Bang in the event of inflation itself one of the most vexing problems posed by inflation is just how it's supposed to stop to create just the right conditions for our universe the quantum field powering inflation must slowly evolve to its lowest energy State and then finally come to rest if the quantum field evolves too quickly the universe expands too much making a cosmos full of life impossible and the end state known as reheating must also follow a particular path too much or too little energy injected back into the universe would render it desolate to cosmologists this seems very very unlikely oddly finely tuned a strangely lucky coincidence if the quantum Fields behaved any differently even very slightly then our universe would have just kept on rapidly expanding never slowing down never coming to rest and never becoming populated with particles and Fields and stars and galaxies and so this is where the concept of Eternal inflation comes in in this model once inflation starts up in the infant Universe it just keeps going the entire universe in the broadest possible sense keeps exploding doubling over itself in a NeverEnding Cascade of accelerated expansion like a race car driver that never lets their foot off the pedal the universe's expansion once triggered in the first momentous Act of inflation never knows how to slow down but this does mean that the Universe has an ultimate beginning something had to kick off the first Quantum field to start its Journey towards inflation so no matter what the universe has a finite age in the past but it can live forever into the future there is always another part of the universe experiencing inflated growth on and on and on into Infinity [Music] of course we don't know if our universe our inflation our big bang was the first one though it seems unlikely and if not what would have come before our inflation event was simply a previous one and one before that and so on and so on back into the mids of time but our observable universe is obviously not experiencing this kind of runaway growth there is dark energy and our Cosmos is accelerating in its expansion but compared to inflation this is quite leisurely not the kind of Breakneck Pace powered by these early Quantum Fields so how can we reconcile this observational fact with the concept of NeverEnding inflation to make this work physicist and inflation Theory Pioneer Paul steinhardt proposed that our universe is just a tiny bubble simply a piece of the much larger inflating SpaceTime in our tiny bubble a portion of the inflation driving qu field settled into a low energy State trapped there that local condition caused our universe to separate itself to pinch off from The Wider Cosmos here inflation ended here the portion of the quantum Field behind inflation decayed away into the shower of particles and radiation that we see as the Big Bang but not everywhere beyond the bounds of our univers the rest of SpaceTime continues to inflate and out there in that wider SpaceTime pieces of the quantum field continue to pinch off separate and settle down each time a portion pinches off a new universe is born with a new set of particles and radiation a new realization of the cosmos but of course this proposed Multiverse wouldn't be infinitely big however would quickly approach scales that might as well be in just a single event of inflation our universe already became 10 the^ of 50 times larger than its observable volume and that was from a period of inflation lasting less than 10 the power of minus 30 seconds imagine inflation lasting for an entire second or a minute or 10 billion years or who knows how long since the initial spark this is the inflationary Multiverse a giant evergrowing collection of individual universes each universe is separated from the next by an almost uncountable number of light years and that distance is growing because inflation causes space to expand faster than light each bubble universe is flying away from every other bubble Universe faster than light there can be no connections among them no communication no influence and surprisingly it is possible at least in principle to test this idea even though the other universes of the Multiverse are unreachables that Collision would appear to us as a circle in the sky a ring created at the intersection of our two bubbles many researchers have searched for these circles both in maps of galaxies across the modern day universe and within the cosmic microwave background however while there have been some intriguing hints of a signal to date nothing has withstood further scrutiny this lack of a detection does not rule out the Multiverse idea because there was only a slim chance anyway that our young universe would have intersected with another but unfortunately beyond that idea there aren't really any rigorous ways to detect the existence of the Multiverse Since By definition the rest of the inflating Universe exists beyond our observable Horizon impossible to reach and it is because of this that many theoretical physicists have decried the idea of the Multiverse arguing that it's not a valid scientific theory indeed among these are Paul steinhardt himself even though he was one of The Originators of the Eternal inflation idea he later turned to become a vocal critic of all inflation theories after all the Multiverse fails to explain anything about our own particular Universe within the Multiverse every possibility every Arrangement and every combination of particles and forces is possible that means there's nothing special about this particular Arrangement that we find ourselves in but there's also nothing special about any other Arrangement you simply can't tell from observations of your own Universe whether the Multiverse exists or not which unfortunately isn't a very good way to build scientific theories on top of this it's also currently impossible to tell the potential variety of universes contained in the Multiverse as the details would depend on the exact physical mechanism that drove inflation in the first place and when exactly inflation occurred in the simplest scenario the bubbles of the Multiverse are just more Universe the same forces fields and particles that we're used to here just in a variety of combinations if we could visit another bubble Universe for example we would see the familiar photons and gluons and quarks and so on and those particles would interact VI the same forces that we have here so there would still be stars and galaxies and a cosmic web just in a different pattern but depending on what powers inflation it's also possible that those universes could have different combinations of particles and forces or even different fundamental constants different bubble universes could have different speeds of light or different electron masses or no electrons at all much of the physics that we take for granted could be totally different of course most of those bubble universes would be completely inhospitable to life or the formation of stars or even macroscopic structures in general but with so many universes everything gets a chance this is one of the strange features of such a large mult Multiverse and also with infinite multiverses there isn't just one occurrence of every single possibility there are a huge number of occurrences of every single possibility this means that there would be countless bubbly universes where Dark Energy just rips everything apart before anything can form there would be countless universes where light travels too slowly there would be countless universes where electrons are the size of footballs and there would be countless universes where everything is just fine with the same kind of physics as we have in our universe and the possibility of copies of you comes from the idea that there might only be a finite number of ways to combine all the matter in the universe this idea is hypothetical relying on our current understanding of quantum information if it's true and there really are only a limited number of ways that electrons quarks neutrinos photons and dark matter can position themselves in any Universe then with a large enough amount of bubble univers ver is within the Multiverse each and every combination of particles wouldn't just appear once but many many many [Music] times but this remarkable extrapolation doesn't answer the key question how could we ever know if it's practically impossible to test what other options do we have the there is one possibility physicists including Andre Lind one of The Originators of Eternal inflation think we could gain hints of this Multiverse through theory if we can find a mechanism behind inflation and are able to test that then we would know for sure that inflation happened because of an out ofcontrol Quantum field and if we can prove that Eternal inflation is a generic feature of that particular inflation model then we can be confident that a Multiverse EX exists but what theory could explain such an extreme event well without realizing it as it turned out the early pioneers of Eternal inflation were developing the physical grounding needed to explain one of the most challenging aspects of string theory the infamous leading candidate for a Theory of Everything the Troublesome fact that string theory can't tell us what kind of universe we live [Music] in Legend has it that in the ancient land of friia in what is today Central turkey there was a knot tied to an ox cart it was no simple knot the legend had grown that anyone who could untie this knot which was so complex so intertwined and so comp liated that nobody could figure out where it began or ended would eventually rise to become king of all Asia and so hearing of this Legend the Macedonian ruler and General Alexander the Great had sorted out he was in the midst of his conquest of the Persian Empire and very much wanted what the knot promised there the knot stood strong tied fixed implacable as his followers looked on Alexander had devised a clever simple Swift solution he took out his sword and cut the knot in [Music] two modern theoretical physicists may not share many similarities with Alexander the Great but they did discover a gan KN of their own and came up with an equally Swift and brutal solution string theory is an audacious attempt to do two things at once on the one hand it promises to provide a quantum theory of gravity which has remained an unsolved riddle in physics ever since the development of the seemingly irreconcilable general relativity and quantum mechanics over a century ago try as they might physicists have routinely failed to definitively bring gravity into the quantum realm though string theory is still the most popular attempt simultaneously String Theory also hopes to be a Theory of Everything literally a single Theory grounded in a simple set of equations that describes our entire reality explaining what the forces of nature are and why they have the properties that they do along with explaining all the particles of Nature and why they have the properties they do ultimately if String Theory lives up to its promise if you have any question about fundamental physics it will have the answer string theory hypothesizes that what we think of as particles are anything but the fundamental units of reality of vibrating Loops different vibrations of the loops correspond to different particles like different vibrations on a pluck to guitar string correspond to different notes but three dimensions just isn't enough for these tiny strings to vibrate in in all the ways needed to explain the vast array of particles that we observe in nature so String Theory also posits the existence of extra spatial Dimensions either 10 or 11 depending on the Theory but all these extra dimensions are invisible to us curled up on themselves at the smallest of scales well below the threshold of anything we could ever hope of detecting and even though we have no evidence for the existence of these extra Dimensions they are necessary for string theory to work for it is within these extra Dimensions that the strings have the freedom they need to vibrate in all the ways they need to but there is one not insignificant problem with this curled up extra Dimensions idea and that is that all the extra dimensions of the universe can curl up on themselves in a tremendously huge number of ways there are somewhere around 10 to the power of 500 different options each one of these options places a different set of restrictions on the vibrations of the string just like different guitar neck lengths change what kind of notes the instrument could can make because the vibrations of the strings are responsible for the physics that we see in the universe and the shapes of all these extra Dimensions govern how the strings can vibrate each potential way of curling up the extra Dimensions gives rise to a completely different Universe with different particles different forces and different fundamental constants and we just don't know which Universe we live in we don't have the sophistication yet to understand the Tangled mathematics of string theory we know that the shapes of the extra Dimensions determine vibrations and that vibrations give rise to particles but we don't know how all of that works if you hand a string theorist a particular configuration of the extra Dimensions they couldn't tell you what kind of physics arises from it string theorist Leonard suskind called this the landscape it's the set of all possible configurations of the extra Dimensions each one leading to a completely different set of laws of physics for a universe this landscape is imaginary it's a mathematical mapping of all the possibilities and our universe occupies one single point in this landscape just one Speck amongst all the 10 to the power of 500 possibilities to visualize ize this landscape imagine walking barefoot through a vast field filled with Rolling Hills sporadic Rocky outcrops wooded Glades peaceful streams and Placid Lakes as you Traverse the field every step you take samples a different portion of it perhaps one footstep lands on a soft cushion of lush grass perhaps another slips against a moss covered Stone and yet another plunges into frigid Waters but the landscape laid before you isn't just a universe it's a universe of possibilities a mathematical construct that contains all the variations of a cosmos that could possibly exist within String Theory each step represents the realization of one Universe one Cosmos one arrangement of matter and forces and radiation and constants the Lush Hill to your right that's a region where the cosmological constant has a small enough value for life to survive the bear patch on the other side of the Hill gravity is too strong there the Swift Current of the river is all the universes where the speed of light is too fast or the electric charge too low our universe exists as a single point in this landscape one particular sample from the grand tapestry where the nature of the cosmos permits life to exist where the configurations of the extra Dimensions allow just the right vibrations of strings to make stars galaxies and us but even if we did know how to connect configurations of extra Dimensions to vibrations of strings we still wouldn't have a way to explain why our universe manifested in this particular way why did our universe choose this arrangement of Dimensions instead of any of the others this Arrangement seems favorable to the development of intelligent life at least as far as we understand it but most of the others a presumably void too big too cold too small too weird so as string theorists began to develop the concept of the landscape they kept running into this nasty Guardian knot why were these extra dimensions of our universe tied up in this particular way instead of any other was it just an accident or was there something more and this is where Eternal inflation could save the day the landscape was a deeply hypothetical idea a plane of possibilities mapping out every allowable universe but it wasn't a thing it wasn't a place that birthed new universes or a whiter meta universe but Eternal inflation and its implied Multiverse though also highly theoretical they were concr R physical and so in the 1990s string theorists like Leonard suskin and cosmologists like Andre lindai and samartin REE got together they realized that they were coming at the same problem from opposite directions the cosmologists were trying to understand the properties of our universe and hit upon the concept of a Multiverse that ours was just one of many the string theorists were grappling with the possibility of an astounding number of possible universes of which our was just a single realization perhaps this was no mere coincidence perhaps there was something deeper going on the string theorists could imagine the landscape but didn't know how to create a universe from it and yet here was the Multiverse a way that inflation naturally effortlessly constructed every possible kind of Cosmos the Multiverse idea through Eternal inflation gives a physical mechanism to the string l Escape in other words the Multiverse could be how the string landscape manifests itself each new bubble Universe can have its own set of physical laws its own population of particles and energies and forces each one of those bubbly universes corresponds to a singular point on the landscape and each one of those universes is a sample of the possible configurations of the extra dimensions a single chord on the instrument of the cosmos that vibrates its own unique set of frequencies but as alluring as this concept is as of right now the connections between string theory and eternal inflation ATT tenuous at best we do not fully understand the physics of inflation assuming that inflation even is a correct description of the extremely early universe that means that we don't know how deep the Multiverse goes whether the bubble universes only sample different Arrangements of the familiar forces or particles or manifest new configurations of the extra Dimensions that lead to brand new physics but the connection is attractive that not only is our universe one of many but over the span of creation every possible manifold arises every kind of possibility this also saves String Theory from the seemingly impossible task of having to explain why our universe has the properties it has why it has this particular curling of extra Dimensions instead of any other with every possibility realized with every kind of Cosmos manufactured we are guaranteed to find ourselves only in a universe that has the physics to make us possible we are here at this point in the string landscape because we could not exist anywhere else those universes are out there sampling every portion of the landscape countless times but they are almost all empty and devoid of life we are here in this one because it is the only universe that we can call home this line of thinking is known as the anthropic argument that the universe is the way it is because otherwise we wouldn't be here to observe it and so while it is the ultimate conclusion of the string landscape and Multiverse ideas combined many scientists argue that this line of thinking has LED nowhere useful we can't ever directly test the string landscape because according to the string landscape we were always going to arise anyway we can't say why our universe has this configuration beyond that it is compatible with Life in response some theorists have attempted to put the landscape on firmer grounds for example using some simplified calculations born from String Theory they hope to be able to say that the amount of dark matter or dark energy or the mass of the electron or any the other parameters that makes physics work the way we know it to work are the most probable outcomes in the landscape that kind of analysis won't erase worries over the anthropic argument but it would at least ease some of the concern that our specific universe is so special and finely tuned but of course again this is all highly speculative we don't know how or even if the string landscape connects to Eternal inflation but if it does it offers a startlingly different view of of our universe and the Big Bang before the Big Bang there would be inflation before inflation there would be Eternal inflation and the Multiverse and before it all would be the string landscape but not in the sense that the landscape is a physical entity the idea is that before there was even the possibility of the cosmos there was the reality of string theory and the landscape with these rules in place the universe could simply proceed evolving according to the machinations of strings and higher Dimensions that manifested in the event of the first inflation which began the race towards multiplicity and from there the separate bubble universes expanded and explored discovering every nook and cranny of all possible string Dimensions but this extension of thought where the ground is in string theory in the Multiverse or some other Theory of physics that we've yet to dream of leads us back to the ultimate question why is there something rather than nothing what created the string theory landscape what came before the before the Big Bang if the laws of physics made the universe our Cosmos the Multiverse the landscape possible then why are there laws of physics in the first place [Music] there was a time before your birth and before you were born before your mind organized itself into conscious awareness before there was you the universe still existed the evidence is all around you your parents the memories and stories of older Generations photographs and momentos and monuments from before their time your birth may have been the beginning of you but it was not the beginning of the world and so is this the case with our universe 2 or our Multiverse we have seen that our Cosmos may have ignited in a Quantum fire known as inflation that inflation event may not have been alone it may be part of a NeverEnding string of Eternal inflation creating a grand Cosmos that will continue inflating forever and in the process unfolding a Multiverse of possible bubble universes and that Multiverse potentially solves the riddle of the string landscape in the process explaining why our universe has the properties it does to be amable to life and intelligence but though motivated by Decades of research into theoretical physics string theory Still Remains speculation there is no experiment that has validated the theory and indeed because we lack the mathematical sophistication to tie together configurations of the extra Dimensions with the vibrations of the strings we actually can't test String Theory as powerful as its mathematics may be it is not yet risen to the challenges that a proper physical Theory must overcome it cannot make predictions that can be tested against experiment even Eternal inflation while still on Shaky Ground is at least motivated by a physical Theory grounded in our current understanding of physics the language of quantum fields and most cosmologists strongly suspect something like inflation happened in the early universe that said there are other Alternatives the story of inflation Eternal inflation and the string land Escape is not the only approach to peering into the gray Mists behind our big [Music] bang in 2001 four physicists Justin Cy Bert over Paul steinhardt and Neil turo proposed a completely different cosmological model one that was still anchored in the latest thinking on string theory but without the need for inflation at all in this model before our universe before what we would call The Big Bang the cosmos was composed of Giant floating brains these brains are not biological networks but the name given to cosmic strings that stretch over more than one dimension in this model our three-dimensional universe is one such gigantic brain and it floats in an endless void of higher dimensional reality unfortunately we cannot access these higher Dimensions because the particles that make up our reality are restricted to live on this brain and so our universe only appears three-dimensional long ago this Theory posits before our big bang the brain of our universe was cold empty and featureless but it was not alone there were other brains existing in the higher dimensional reality as well and at some time another brain collided with our own the brains met at a point releasing a storm of energy and triggering shock waves that rippled through them from our perspective embedded inside the brain this looks like a big bang a hot flash of energy at a singular point that floods the cosmos with particles and radiation known as EC pyrotic cosmology from the Greek word for fire the model is able to reproduce the broad properties of our Cosmos the flatness the lack of defects the appearance of a big bang expansion and even the formation of structures without invoking inflation and without building a Multiverse this e pyrotic model also has one additional feature the ability to reignite the cosmos our brain could Collide again with another one in that higher dimensional space that would start the process over again igniting a fresh Big Bang what we see as a singular event in our past is then just as regular and repeatable as a ball bouncing on the floor and the ecrotic model isn't the only one that claims we live in a never ending cycle of Big Bangs another approach to solving the riddle of marrying gravity with quantum mechanics known as Loop quantum gravity suggests that what we see as a smooth and unbroken fabric of SpaceTime is really a series of discrete elements like the pixels of your computer screen in our classical understanding of cosmology rooted in general relativity the universe begins as a singularity a point of infinite density but in Loop quantum gravity there's no such thing as the Big Bang it is impossible to bring matter or space or time into a region smaller than the fundamental pixels of reality when one attempts to do so a pressure emerges that resists the collapse the same way a spring gets hard to push the smaller you make it so when the universe collapses in on itself it reaches a point where natural Quantum reactions fling it back outwards subverting the appearance of a singularity and igniting a new Big Bang in the process and there are still more models and ideas that allow for the creation of new universes like Roger penrose's conformal cyclic cosmology in this model in the extremely distant future the universe is so thin so cold and so spread out that space and time are rendered meaningless opening up the Poss ability of a new Big Bang springing to life and so whatever the case may be the answer to the origins of our big bang whether through inflation String Theory Loop quantum gravity or something even more exotic lies somewhere in the land of quantum gravity we have to understand how gravity operates at extreme scale scales to push deep enough into our own past that we can understand the origins of our universe we know that the singularity of general relativity the infinitely tiny point at the beginning of our Cosmos is wrong it is simply assign that our mathematics is breaking down and we need a new understanding and that new understanding may even require rewriting the definition of time itself our conception of the univers unverse includes not just particles and radiation not just forces and interactions but the very fabric of SpaceTime itself of course we can Envision a beginning to space an imaginary spark that allows space to manifest and unfold itself becoming the universe as we see it but the beginning of time how can there be cause and effect before the existence of Time how can the clock of our universe start before there was a clock the beginning of the universe includes every feature of it including time itself so we can push the beginning of our universe beyond the edge of the big bang into the realm of Eternal inflation and the string landscape but even in these most advanced and hypothetical ideas there is still a start still a beginning still a time at which time begins if this sounds like a paradox it's because it is there is much about time that we currently do not understand and may never understand so what can we do our conceptions of time in physics are already muddled and contradictory in quantum mechanics time is treated as an external parameter a fact of the universe that uniformly marches forward allowing observers to make observations and for interactions to take place whereas in general relativity time is fluid relative and tied into space through a harmonious fabric to understand the universe we must reconcile these perspectives very simply we cannot speak confidently about a moment before time until we can understand with confidence what time exactly is and so for now our thoughts on space and time aren't sophisticated enough to Grapple with the beginning of it all because terms like begin are so rooted in our biological existence so grounded in our fundamental conscious perspectives on the world around us that we may not be able to escape our biases even when we extend them to the farthest reaches of our most advanced theories indeed the very process of time the segregation of the past present and future may break down in the early Universe conditions may become so extreme that the separation between before and after may lose all meaning caus ity may become a jumbled mess in the earliest moments of the cosmos moments may be [Music] meaningless this means it may ultimately be fruitless to search for an ultimate beginning a before the Big Bang because time itself at least the way we currently grasp it would become a useless framework for organizing the universe and yet even if we could surmount all these difficulties that would still not be the end because no matter what no matter which Theory we propose to explain our own Origins whether an infinite chain of multiverses or colliding brains or an endless cycle of repeated Big Bangs there is still something rather than nothing there is still physics there are still rules laws and ordered Harmony that allow for the existence of the cosmos if it's inflation then there's a Quantum field if it's colliding brains or a landscape then it's strings if its Loop quantum gravity then its discrete units of SpaceTime and our voyages into the horizons beyond the beginning of the Big Bang will undoubtedly reveal even more rules more structures more laws that allow for the creation of laws and so whatever we find there a fundamental reason that reality exists and is may just be forever Beyond us 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

the Big Bang did not bang it did not explode it was not a bomb it was not a detonation or a conflagration there was no blast no debris no shrapnel the universe was simply smaller in the past and it will be bigger in the future and that is not the only misconception you may have about the Big Bang to begin with the big bang didn&#39;t happen anywhere it happened everywhere it was not an event in space but rather an event in time it was the tick on a clock not the notch in a ruler it occurred in the finite past of everything in the cosmos every atom every particle every Point can trace its evolutionary origins back through the eons to the Big Bang the Big Bang happened in the room you&#39;re in right now it happened in the Andromeda galaxy it happened inside you it happened within the entire expanse of the known and unknown universe the entire universe was smaller hotter and denser in the past now it&#39;s not that is the great lesson of the big [Music] bang and so the universe has no Center and no Edge it expands from nowhere and expands to Nowhere the universe did not originate from a single point in Space the Big Bang was a point from which space originated it in these statements lies an inconsistency a paradox 13.78 7 billion years ago our theories tell us that the Universe the entire universe regardless of its size even if infinite was contained somehow in a singularity a point of infinite density and no spatial extent but this makes no sense this does not obey the rules of reason or logic and this is because the Big Bang Singularity is not a true representation of what everything was it is simply a heavy hint that our equations our maths our physics is dysfunctional The Singularity is a sign that we do not understand our Origins the earliest moments of the Big Bang but in the darkness of that uncertainty is nurtured the seed of a new Awakening for in our ignorance of the Big Bang we have the opportunity for now only seen as the ghosts and Whispers of mercilessly complicated mathematics to pierce the veil of our own beginning to try and deduce what came before the birth of everything because at one time there was no universe and then there was this is the mystery of creation the Paradox of our reality revealed by the existence of the expansion of the universe but was that beginning truly the beginning did Time start with the big bang did our universe come into existence only at that moment or was there something before either similar to our Cosmos or entirely different if the Big Bang was the beginning of everything that we know was it also the beginning of literally everything or is our universe just a small part of a grander fabric greater story that has been told since the distant ages of time past and will continue to exist well after our Cosmos has sunk into cold [Music] Oblivion in 2022 incredible results started to arrive from the new James web Space Telescope but rumors online and in the Press started to spread that they were a death Nowell for The Big Bang Theory of course this was not the case and served as a great example of the importance of media literacy which is why I&#39;m excited to have ground news kindly sponsor this video ground news Aggregates the world&#39;s news in one place so you can compare coverage and verify your information and it&#39;s been a big help in my research for example last month solar storms were reported to disrupt communication and produce Northern Lights as far as the southern us on ground news I was able to access over 200 articles published on on this at a glance nearly 90% were from sources rated highly factual indicating coverage is less subjective which is important for science news comparing coverage is also interesting NPR suggested the storms disrupted Communications while the majority of the sources including f.org emphasized the northern lights and no serious problems and so if you&#39;re looking for a better way to get the full picture I encourage you to visit ground. news/ subscribe through my link to save 40% off unlimited access and by subscribing you&#39;re not only supporting the channel but transparency in the media as well it was 2013 and it was time to party the attendees gathered in the main hall of the Paris Observatory a ground building situated on the south side of Paris near the old gates to the city people got up to speak to congratulate each other on the successful Mission and a job well done including some remarks that there was of course more work to be done in the coming months but before anyone could dwell too much on the tasks ahead they marveled as cases were brought out from a back room the cases were full of champagne but not just any champagne the organizers of the party had commissioned a special bottling and the bottles had custom labels on each bottle was printed an oval disc with an odd speckled pattern that pattern was the cosmic microwave background or CMB a background radiation from just after the big bang that fills the entire universe the European space agency&#39;s plank satellite had collected the data to construct that image the highest resolution all Sky image of the CMB ever made the party goers was celebrating the first public release of the plank satellite data and they had every reason to celebrate the data taken by plank had confirmed the existing cosmological model and the story of The Big Bang and on top of this it had found evidence that the theory of inflation a hypothetical event where the very early Universe grew exponentially larger in a short amount of time was on the right track the Big Bang wasn&#39;t really a big bang what we call the big bang a name coined somewhat derisively by astronomer Fred Hy is really just a generic description of the model of the universe where our Cosmos used to be smaller in the past and will be larger in the future in this model there really isn&#39;t an explosive event that launches the creation of the universe or a swift unfolding of space that gives rise to everything we know instead it&#39;s much simpler it is just a mere EXP expansion from a smaller state to a bigger one and from that theory we can assign a number 13787 with an uncertainty of 0.02 a simple number but this number is special it&#39;s our current best estimate in billions of years of the age of the universe indeed a direct consequence of The Big Bang Theory is that there was a time before time there was a moment when the universe simply became and that moment existed 13.78 7 billion years ago but that&#39;s only the dimension of time as far as we know the three dimensions of space that also make up our universe could be infinitely big yes there is a limit to our observable Cosmos a boundary set by the finiteness of the speed of light that limit sits about 45 billion light years away beyond that we presume that there is more Universe more stars and galaxies and gas and dust but we don&#39;t know it could be infinite but not in the direction of time our universe could live infinitely into the future even when our Cosmos expands so far and so much that all the stars die out and existence is nothing more than a thin soup of particles near a temperature of abs absolute zero the universe will still exist time will still march forward directions in space will still be in place but the past is different there is a limit to what we perceive a boundary of our understanding even if the universe is infinitely big and will extend forever into the future it all came from something [Music] this simple straightforward Big Bang model has been able to explain a wealth of observational data like the apparent recession of galaxies away from us the appearance of the cosmic microwave background even the amount of Light Elements in the cosmos in fact no other cosmological theory is able to explain the existence of all those facts but just like any other scientific theory or model the Big Bang also has its shortcomings and in 1979 physicist Alan Guth was poking at one of those shortcomings in most theoretical models of the extremely early Universe at the time the cosmos seemed to naturally produce a significant number of defects things like magnetic monopoles cosmic strings and other bizarre Intergalactic warpings of space and time however none of these audities had ever been observed in the real the universe and so goth was trying to find a way to get rid of them in a stroke of Pure Imagination he wondered if the Big Bang really was a little more like its namesake than we&#39; previously suspected a little Banger and so he proposed a new entity to inhabit the cosmos something called a Scala field scaler Fields were not a new idea in physics quantum field Theory which alongside Einstein&#39;s general theory of relativity underlies our understanding of reality is strange everything that exists every particle and every form of radiation is really the manifestation of an underlying Quantum field that fills the universe these Quantum Fields soak space and time the same way that olive oil and vinegar soak a piece of bread every particle has its own Associated field one for the photo known as the electromagnetic field one of the electrons known as the direct field and so on and so on when one of these Quantum Fields has a local excitation a region of higher energy vibrations we see that as an independent particle but of course even when a patch of the universe contains no particles the field is still there scal of fields are the simplest kinds of fields to exist they just have a single value a magnitude associated with every every point in SpaceTime every time you see a weather forecast with a map of temperatures across your local region you are looking at a Scala field a single number in this case a temperature associated with every point on the map the eminent physicist Peter higs had already introduced the language of scaler Fields decades before gooth when he proposed what is now called the higs field a scaler field working in the background of SpaceTime that is responsible for Mass but now it was goo&#39;s turn to invent a new scaler field that radically altered the Dynamics of SpaceTime in the distant past this scaler field would permeate all of space and time simply existing in the early Universe then randomly and suddenly this scaler field would experience a dramatic phase transition collapsing itself into a lower energy State this collapse would provide the energy necessary to make the infant Universe much much bigger in a very short amount of time indeed Guth estimated that if the universe inflated by at least a factor of 10 to the power of 50 or so in less than a second then all of those Troublesome defects would simply be scattered to the four corners of the cosmos while outside are observable limits and as well as this the process of a rapid inflation event would solve two other challenges to the traditional Big Bang model it would explain why why the universe could have a uniform temperature despite its enormous size because prior to inflation the cosos homogenized and why it appeared so flat if you take any geometry you want and make it really really big then it will always appear flat to any local observers just like the Earth appears flat in your garden and so because this idea of inflation so neatly explains several features of the observed Universe cosmologists began taking it seriously and within a few years guth&#39;s origin idea evolved in the modern conception of inflation first proposed independently by Andre lindai and the team of Andreas albrech and Paul steinhardt the quantum field didn&#39;t just suddenly jump to a new state but instead slowly evolved into a lower energy state it is this slow roll inflation that allows the theory to put the bang in the Big Bang at first the inflation Quantum field evolves into a lower energy State and Powers the act of inflation but at the end of this inflation when the field is exhausted the universe is large cold and empty but this is where the magic of slow roll inflation comes in through a process called reheating at the end of inflation the quantum field doesn&#39;t just sit still in its lowest energy State just like a ball that&#39;s rolled down down a hill the field wobbles a little this wobbling transfers even more energy back into the cosmos not in the form of super rapid accelerated expansion but in the creation of particles in quantum theory this is allowed Quantum Fields transform and intermingle all the time so in its dying breath the quantum field responsible for inflation decays away filling the universe with all the particles of everyday existence the electrons the photons the neutrinos and quarks even the dark matter and so if there&#39;s anything that fits the popular conception of the Big Bang inflation is it prior to this event the universe was small hot and dense when it was less than the tiniest fraction of a second old however inflation switched on in another tiniest fraction of a second the cosmos exploded in size and at the end of that stupendous expansion the universe relit itself suffused with energy from the inflation field spawning the particles that continue to inhabit the modern-day universe but while this model can handly explain many cosmological Mysteries that&#39;s not quite enough for it to rank as a true scientific theory at the same level of prestige as say general relativity or The Germ theory of disease most importantly when it comes to inflation we have more questions than answers we do not know the identity of the quantum field that drove it for even if it survives to the present day it would be just as a broken shadow of its former self sitting well beyond our ability to detect it we also don&#39;t know why inflation lasted as long as it did or why it had just the right Evolution to power super rapid expansion then Decay away flooding the cosmos with particles some cosmologist argue that due to these deficiencies inflation is not a sound scientific theory but the general concept of inflation that a Quantum field slowly evolved and triggered rapid expansion followed by a flood of particles does make some generic predictions that are testable and in fact have been tested the act of inflation didn&#39;t just rapidly expand the universe it rapidly expanded all the tiny quantum foam that inhabits SpaceTime that quantum foam is sub microscopic existing at the lowest level of reality the incredible expansion of the cosmos under inflation turned that foam into still very small variations but definitely bigger than they were and this formed the seeds of structure tiny variations in SpaceTime led to gravitational differences from place to place place and over time these differences grew eventually becoming the grandest structures in the universe generic theories of inflation regardless of the precise mechanics of the model predict very particular statistical properties of structure in the universe that we observe and the cleanest way to measure those structures is through mapping the cosmic microwave background the leftover light from when the universe was only 380,000 years old one major test of inflation involves something called the Scala spectral index the map of the cosmic microwave background contains many variations blotches of various sizes representing colder and hotter parts of the cosmos cosmologists can turn this map into a spectrum measuring how many large fluctuations there are how many medium and how many small a scaler index of one would tell us that every size of fluctuation adds the same contribution to the general pattern inflation models generally predict a scaler index slightly less than one and in 2013 the plank missions measured this number to be .96 to an accuracy of 5 Sigma the plank satellite measured the exact statistical properties predicted by inflation certainly a champagne worthy event and so even though inflation sits Beyond the Edge of known physics involving properties and forces and Fields that we do not yet comprehend most cosmologists believe that something like inflation happened in the early Universe while there are other hypothetical alternatives to the inflation story in the end they all tend to operate in much the same way a rapid expansion of space a flooding of particles and the planting of the first seeds of structure so even if in infation turns out to be an incorrect theory of nature by all available evidence the universe underwent something extraordinary in its earliest moments something that gave rise to the Big [Music] Bang but if inflation is correct if there was some exotic Quantum field that drove a super rapid expansion of space and ignited the Big Bang then the theory has some intriguing implications because before the Big Bang there was inflation and before inflation there was a NeverEnding stream of inflation in this view powered by Cutting Edge theoretical physics what we think of as our universe is just one in an infinite chain of universes each one bubbling and branching off of a stream that will continue forever inflation always was and always will be if this theory is correct then what came before the Big B hang before our universe was the [Music] Multiverse in Fodor Doo&#39;s 1846 novel The Double A Petersburg poem a struggling young bureaucrat finds an unlikely companion a man who looks exactly like him except more fearful at first the two men are friends but then the Double&#39;s Charisma starts to take over the original&#39;s life in the end the original finds many copies of himself and is forced into an asylum and though this is a fictional story the concept behind it is not as farfetched as it might seem because somewhere in a galaxy far far away there could be a copy a copy of you wearing the same clothes as you the same age as you the same life experiences lovers relatives as you the same favorite restaurant and hated sports team that copy of you who also goes by the exact same name as you could be watching a copy of this video right now in parallel the two of you watching it on exact duplicates of the screen at the same point in the video hearing the exact same information with the same voice this copy would be inhabiting another universe and this universe would be extremely distant from ours far far beyond the observable bounds of our Cosmos we could never access it never travel there and never exchange information with it but it could exist an exact replica down to the subatomic level and that copy would not be alone somewhere even more distant than the nearest copy would be another one and another and another in fact there would be an Infinity of use all watching this same video in this precise moment this is the reality of an infinite Multiverse a cosmos big enough to contain an Infinity of universes so large that it encompasses every possibility every combination of molecule and atom and subatomic particle and it copies each and every possibility an infinite number of times both in the present and extending far into the future the concept of a Multiverse is staggering in its scope but its tantalizing possibility is born in the fires before the Big Bang in the event of inflation itself one of the most vexing problems posed by inflation is just how it&#39;s supposed to stop to create just the right conditions for our universe the quantum field powering inflation must slowly evolve to its lowest energy State and then finally come to rest if the quantum field evolves too quickly the universe expands too much making a cosmos full of life impossible and the end state known as reheating must also follow a particular path too much or too little energy injected back into the universe would render it desolate to cosmologists this seems very very unlikely oddly finely tuned a strangely lucky coincidence if the quantum Fields behaved any differently even very slightly then our universe would have just kept on rapidly expanding never slowing down never coming to rest and never becoming populated with particles and Fields and stars and galaxies and so this is where the concept of Eternal inflation comes in in this model once inflation starts up in the infant Universe it just keeps going the entire universe in the broadest possible sense keeps exploding doubling over itself in a NeverEnding Cascade of accelerated expansion like a race car driver that never lets their foot off the pedal the universe&#39;s expansion once triggered in the first momentous Act of inflation never knows how to slow down but this does mean that the Universe has an ultimate beginning something had to kick off the first Quantum field to start its Journey towards inflation so no matter what the universe has a finite age in the past but it can live forever into the future there is always another part of the universe experiencing inflated growth on and on and on into Infinity [Music] of course we don&#39;t know if our universe our inflation our big bang was the first one though it seems unlikely and if not what would have come before our inflation event was simply a previous one and one before that and so on and so on back into the mids of time but our observable universe is obviously not experiencing this kind of runaway growth there is dark energy and our Cosmos is accelerating in its expansion but compared to inflation this is quite leisurely not the kind of Breakneck Pace powered by these early Quantum Fields so how can we reconcile this observational fact with the concept of NeverEnding inflation to make this work physicist and inflation Theory Pioneer Paul steinhardt proposed that our universe is just a tiny bubble simply a piece of the much larger inflating SpaceTime in our tiny bubble a portion of the inflation driving qu field settled into a low energy State trapped there that local condition caused our universe to separate itself to pinch off from The Wider Cosmos here inflation ended here the portion of the quantum Field behind inflation decayed away into the shower of particles and radiation that we see as the Big Bang but not everywhere beyond the bounds of our univers the rest of SpaceTime continues to inflate and out there in that wider SpaceTime pieces of the quantum field continue to pinch off separate and settle down each time a portion pinches off a new universe is born with a new set of particles and radiation a new realization of the cosmos but of course this proposed Multiverse wouldn&#39;t be infinitely big however would quickly approach scales that might as well be in just a single event of inflation our universe already became 10 the^ of 50 times larger than its observable volume and that was from a period of inflation lasting less than 10 the power of minus 30 seconds imagine inflation lasting for an entire second or a minute or 10 billion years or who knows how long since the initial spark this is the inflationary Multiverse a giant evergrowing collection of individual universes each universe is separated from the next by an almost uncountable number of light years and that distance is growing because inflation causes space to expand faster than light each bubble universe is flying away from every other bubble Universe faster than light there can be no connections among them no communication no influence and surprisingly it is possible at least in principle to test this idea even though the other universes of the Multiverse are unreachables that Collision would appear to us as a circle in the sky a ring created at the intersection of our two bubbles many researchers have searched for these circles both in maps of galaxies across the modern day universe and within the cosmic microwave background however while there have been some intriguing hints of a signal to date nothing has withstood further scrutiny this lack of a detection does not rule out the Multiverse idea because there was only a slim chance anyway that our young universe would have intersected with another but unfortunately beyond that idea there aren&#39;t really any rigorous ways to detect the existence of the Multiverse Since By definition the rest of the inflating Universe exists beyond our observable Horizon impossible to reach and it is because of this that many theoretical physicists have decried the idea of the Multiverse arguing that it&#39;s not a valid scientific theory indeed among these are Paul steinhardt himself even though he was one of The Originators of the Eternal inflation idea he later turned to become a vocal critic of all inflation theories after all the Multiverse fails to explain anything about our own particular Universe within the Multiverse every possibility every Arrangement and every combination of particles and forces is possible that means there&#39;s nothing special about this particular Arrangement that we find ourselves in but there&#39;s also nothing special about any other Arrangement you simply can&#39;t tell from observations of your own Universe whether the Multiverse exists or not which unfortunately isn&#39;t a very good way to build scientific theories on top of this it&#39;s also currently impossible to tell the potential variety of universes contained in the Multiverse as the details would depend on the exact physical mechanism that drove inflation in the first place and when exactly inflation occurred in the simplest scenario the bubbles of the Multiverse are just more Universe the same forces fields and particles that we&#39;re used to here just in a variety of combinations if we could visit another bubble Universe for example we would see the familiar photons and gluons and quarks and so on and those particles would interact VI the same forces that we have here so there would still be stars and galaxies and a cosmic web just in a different pattern but depending on what powers inflation it&#39;s also possible that those universes could have different combinations of particles and forces or even different fundamental constants different bubble universes could have different speeds of light or different electron masses or no electrons at all much of the physics that we take for granted could be totally different of course most of those bubble universes would be completely inhospitable to life or the formation of stars or even macroscopic structures in general but with so many universes everything gets a chance this is one of the strange features of such a large mult Multiverse and also with infinite multiverses there isn&#39;t just one occurrence of every single possibility there are a huge number of occurrences of every single possibility this means that there would be countless bubbly universes where Dark Energy just rips everything apart before anything can form there would be countless universes where light travels too slowly there would be countless universes where electrons are the size of footballs and there would be countless universes where everything is just fine with the same kind of physics as we have in our universe and the possibility of copies of you comes from the idea that there might only be a finite number of ways to combine all the matter in the universe this idea is hypothetical relying on our current understanding of quantum information if it&#39;s true and there really are only a limited number of ways that electrons quarks neutrinos photons and dark matter can position themselves in any Universe then with a large enough amount of bubble univers ver is within the Multiverse each and every combination of particles wouldn&#39;t just appear once but many many many [Music] times but this remarkable extrapolation doesn&#39;t answer the key question how could we ever know if it&#39;s practically impossible to test what other options do we have the there is one possibility physicists including Andre Lind one of The Originators of Eternal inflation think we could gain hints of this Multiverse through theory if we can find a mechanism behind inflation and are able to test that then we would know for sure that inflation happened because of an out ofcontrol Quantum field and if we can prove that Eternal inflation is a generic feature of that particular inflation model then we can be confident that a Multiverse EX exists but what theory could explain such an extreme event well without realizing it as it turned out the early pioneers of Eternal inflation were developing the physical grounding needed to explain one of the most challenging aspects of string theory the infamous leading candidate for a Theory of Everything the Troublesome fact that string theory can&#39;t tell us what kind of universe we live [Music] in Legend has it that in the ancient land of friia in what is today Central turkey there was a knot tied to an ox cart it was no simple knot the legend had grown that anyone who could untie this knot which was so complex so intertwined and so comp liated that nobody could figure out where it began or ended would eventually rise to become king of all Asia and so hearing of this Legend the Macedonian ruler and General Alexander the Great had sorted out he was in the midst of his conquest of the Persian Empire and very much wanted what the knot promised there the knot stood strong tied fixed implacable as his followers looked on Alexander had devised a clever simple Swift solution he took out his sword and cut the knot in [Music] two modern theoretical physicists may not share many similarities with Alexander the Great but they did discover a gan KN of their own and came up with an equally Swift and brutal solution string theory is an audacious attempt to do two things at once on the one hand it promises to provide a quantum theory of gravity which has remained an unsolved riddle in physics ever since the development of the seemingly irreconcilable general relativity and quantum mechanics over a century ago try as they might physicists have routinely failed to definitively bring gravity into the quantum realm though string theory is still the most popular attempt simultaneously String Theory also hopes to be a Theory of Everything literally a single Theory grounded in a simple set of equations that describes our entire reality explaining what the forces of nature are and why they have the properties that they do along with explaining all the particles of Nature and why they have the properties they do ultimately if String Theory lives up to its promise if you have any question about fundamental physics it will have the answer string theory hypothesizes that what we think of as particles are anything but the fundamental units of reality of vibrating Loops different vibrations of the loops correspond to different particles like different vibrations on a pluck to guitar string correspond to different notes but three dimensions just isn&#39;t enough for these tiny strings to vibrate in in all the ways needed to explain the vast array of particles that we observe in nature so String Theory also posits the existence of extra spatial Dimensions either 10 or 11 depending on the Theory but all these extra dimensions are invisible to us curled up on themselves at the smallest of scales well below the threshold of anything we could ever hope of detecting and even though we have no evidence for the existence of these extra Dimensions they are necessary for string theory to work for it is within these extra Dimensions that the strings have the freedom they need to vibrate in all the ways they need to but there is one not insignificant problem with this curled up extra Dimensions idea and that is that all the extra dimensions of the universe can curl up on themselves in a tremendously huge number of ways there are somewhere around 10 to the power of 500 different options each one of these options places a different set of restrictions on the vibrations of the string just like different guitar neck lengths change what kind of notes the instrument could can make because the vibrations of the strings are responsible for the physics that we see in the universe and the shapes of all these extra Dimensions govern how the strings can vibrate each potential way of curling up the extra Dimensions gives rise to a completely different Universe with different particles different forces and different fundamental constants and we just don&#39;t know which Universe we live in we don&#39;t have the sophistication yet to understand the Tangled mathematics of string theory we know that the shapes of the extra Dimensions determine vibrations and that vibrations give rise to particles but we don&#39;t know how all of that works if you hand a string theorist a particular configuration of the extra Dimensions they couldn&#39;t tell you what kind of physics arises from it string theorist Leonard suskind called this the landscape it&#39;s the set of all possible configurations of the extra Dimensions each one leading to a completely different set of laws of physics for a universe this landscape is imaginary it&#39;s a mathematical mapping of all the possibilities and our universe occupies one single point in this landscape just one Speck amongst all the 10 to the power of 500 possibilities to visualize ize this landscape imagine walking barefoot through a vast field filled with Rolling Hills sporadic Rocky outcrops wooded Glades peaceful streams and Placid Lakes as you Traverse the field every step you take samples a different portion of it perhaps one footstep lands on a soft cushion of lush grass perhaps another slips against a moss covered Stone and yet another plunges into frigid Waters but the landscape laid before you isn&#39;t just a universe it&#39;s a universe of possibilities a mathematical construct that contains all the variations of a cosmos that could possibly exist within String Theory each step represents the realization of one Universe one Cosmos one arrangement of matter and forces and radiation and constants the Lush Hill to your right that&#39;s a region where the cosmological constant has a small enough value for life to survive the bear patch on the other side of the Hill gravity is too strong there the Swift Current of the river is all the universes where the speed of light is too fast or the electric charge too low our universe exists as a single point in this landscape one particular sample from the grand tapestry where the nature of the cosmos permits life to exist where the configurations of the extra Dimensions allow just the right vibrations of strings to make stars galaxies and us but even if we did know how to connect configurations of extra Dimensions to vibrations of strings we still wouldn&#39;t have a way to explain why our universe manifested in this particular way why did our universe choose this arrangement of Dimensions instead of any of the others this Arrangement seems favorable to the development of intelligent life at least as far as we understand it but most of the others a presumably void too big too cold too small too weird so as string theorists began to develop the concept of the landscape they kept running into this nasty Guardian knot why were these extra dimensions of our universe tied up in this particular way instead of any other was it just an accident or was there something more and this is where Eternal inflation could save the day the landscape was a deeply hypothetical idea a plane of possibilities mapping out every allowable universe but it wasn&#39;t a thing it wasn&#39;t a place that birthed new universes or a whiter meta universe but Eternal inflation and its implied Multiverse though also highly theoretical they were concr R physical and so in the 1990s string theorists like Leonard suskin and cosmologists like Andre lindai and samartin REE got together they realized that they were coming at the same problem from opposite directions the cosmologists were trying to understand the properties of our universe and hit upon the concept of a Multiverse that ours was just one of many the string theorists were grappling with the possibility of an astounding number of possible universes of which our was just a single realization perhaps this was no mere coincidence perhaps there was something deeper going on the string theorists could imagine the landscape but didn&#39;t know how to create a universe from it and yet here was the Multiverse a way that inflation naturally effortlessly constructed every possible kind of Cosmos the Multiverse idea through Eternal inflation gives a physical mechanism to the string l Escape in other words the Multiverse could be how the string landscape manifests itself each new bubble Universe can have its own set of physical laws its own population of particles and energies and forces each one of those bubbly universes corresponds to a singular point on the landscape and each one of those universes is a sample of the possible configurations of the extra dimensions a single chord on the instrument of the cosmos that vibrates its own unique set of frequencies but as alluring as this concept is as of right now the connections between string theory and eternal inflation ATT tenuous at best we do not fully understand the physics of inflation assuming that inflation even is a correct description of the extremely early universe that means that we don&#39;t know how deep the Multiverse goes whether the bubble universes only sample different Arrangements of the familiar forces or particles or manifest new configurations of the extra Dimensions that lead to brand new physics but the connection is attractive that not only is our universe one of many but over the span of creation every possible manifold arises every kind of possibility this also saves String Theory from the seemingly impossible task of having to explain why our universe has the properties it has why it has this particular curling of extra Dimensions instead of any other with every possibility realized with every kind of Cosmos manufactured we are guaranteed to find ourselves only in a universe that has the physics to make us possible we are here at this point in the string landscape because we could not exist anywhere else those universes are out there sampling every portion of the landscape countless times but they are almost all empty and devoid of life we are here in this one because it is the only universe that we can call home this line of thinking is known as the anthropic argument that the universe is the way it is because otherwise we wouldn&#39;t be here to observe it and so while it is the ultimate conclusion of the string landscape and Multiverse ideas combined many scientists argue that this line of thinking has LED nowhere useful we can&#39;t ever directly test the string landscape because according to the string landscape we were always going to arise anyway we can&#39;t say why our universe has this configuration beyond that it is compatible with Life in response some theorists have attempted to put the landscape on firmer grounds for example using some simplified calculations born from String Theory they hope to be able to say that the amount of dark matter or dark energy or the mass of the electron or any the other parameters that makes physics work the way we know it to work are the most probable outcomes in the landscape that kind of analysis won&#39;t erase worries over the anthropic argument but it would at least ease some of the concern that our specific universe is so special and finely tuned but of course again this is all highly speculative we don&#39;t know how or even if the string landscape connects to Eternal inflation but if it does it offers a startlingly different view of of our universe and the Big Bang before the Big Bang there would be inflation before inflation there would be Eternal inflation and the Multiverse and before it all would be the string landscape but not in the sense that the landscape is a physical entity the idea is that before there was even the possibility of the cosmos there was the reality of string theory and the landscape with these rules in place the universe could simply proceed evolving according to the machinations of strings and higher Dimensions that manifested in the event of the first inflation which began the race towards multiplicity and from there the separate bubble universes expanded and explored discovering every nook and cranny of all possible string Dimensions but this extension of thought where the ground is in string theory in the Multiverse or some other Theory of physics that we&#39;ve yet to dream of leads us back to the ultimate question why is there something rather than nothing what created the string theory landscape what came before the before the Big Bang if the laws of physics made the universe our Cosmos the Multiverse the landscape possible then why are there laws of physics in the first place [Music] there was a time before your birth and before you were born before your mind organized itself into conscious awareness before there was you the universe still existed the evidence is all around you your parents the memories and stories of older Generations photographs and momentos and monuments from before their time your birth may have been the beginning of you but it was not the beginning of the world and so is this the case with our universe 2 or our Multiverse we have seen that our Cosmos may have ignited in a Quantum fire known as inflation that inflation event may not have been alone it may be part of a NeverEnding string of Eternal inflation creating a grand Cosmos that will continue inflating forever and in the process unfolding a Multiverse of possible bubble universes and that Multiverse potentially solves the riddle of the string landscape in the process explaining why our universe has the properties it does to be amable to life and intelligence but though motivated by Decades of research into theoretical physics string theory Still Remains speculation there is no experiment that has validated the theory and indeed because we lack the mathematical sophistication to tie together configurations of the extra Dimensions with the vibrations of the strings we actually can&#39;t test String Theory as powerful as its mathematics may be it is not yet risen to the challenges that a proper physical Theory must overcome it cannot make predictions that can be tested against experiment even Eternal inflation while still on Shaky Ground is at least motivated by a physical Theory grounded in our current understanding of physics the language of quantum fields and most cosmologists strongly suspect something like inflation happened in the early universe that said there are other Alternatives the story of inflation Eternal inflation and the string land Escape is not the only approach to peering into the gray Mists behind our big [Music] bang in 2001 four physicists Justin Cy Bert over Paul steinhardt and Neil turo proposed a completely different cosmological model one that was still anchored in the latest thinking on string theory but without the need for inflation at all in this model before our universe before what we would call The Big Bang the cosmos was composed of Giant floating brains these brains are not biological networks but the name given to cosmic strings that stretch over more than one dimension in this model our three-dimensional universe is one such gigantic brain and it floats in an endless void of higher dimensional reality unfortunately we cannot access these higher Dimensions because the particles that make up our reality are restricted to live on this brain and so our universe only appears three-dimensional long ago this Theory posits before our big bang the brain of our universe was cold empty and featureless but it was not alone there were other brains existing in the higher dimensional reality as well and at some time another brain collided with our own the brains met at a point releasing a storm of energy and triggering shock waves that rippled through them from our perspective embedded inside the brain this looks like a big bang a hot flash of energy at a singular point that floods the cosmos with particles and radiation known as EC pyrotic cosmology from the Greek word for fire the model is able to reproduce the broad properties of our Cosmos the flatness the lack of defects the appearance of a big bang expansion and even the formation of structures without invoking inflation and without building a Multiverse this e pyrotic model also has one additional feature the ability to reignite the cosmos our brain could Collide again with another one in that higher dimensional space that would start the process over again igniting a fresh Big Bang what we see as a singular event in our past is then just as regular and repeatable as a ball bouncing on the floor and the ecrotic model isn&#39;t the only one that claims we live in a never ending cycle of Big Bangs another approach to solving the riddle of marrying gravity with quantum mechanics known as Loop quantum gravity suggests that what we see as a smooth and unbroken fabric of SpaceTime is really a series of discrete elements like the pixels of your computer screen in our classical understanding of cosmology rooted in general relativity the universe begins as a singularity a point of infinite density but in Loop quantum gravity there&#39;s no such thing as the Big Bang it is impossible to bring matter or space or time into a region smaller than the fundamental pixels of reality when one attempts to do so a pressure emerges that resists the collapse the same way a spring gets hard to push the smaller you make it so when the universe collapses in on itself it reaches a point where natural Quantum reactions fling it back outwards subverting the appearance of a singularity and igniting a new Big Bang in the process and there are still more models and ideas that allow for the creation of new universes like Roger penrose&#39;s conformal cyclic cosmology in this model in the extremely distant future the universe is so thin so cold and so spread out that space and time are rendered meaningless opening up the Poss ability of a new Big Bang springing to life and so whatever the case may be the answer to the origins of our big bang whether through inflation String Theory Loop quantum gravity or something even more exotic lies somewhere in the land of quantum gravity we have to understand how gravity operates at extreme scale scales to push deep enough into our own past that we can understand the origins of our universe we know that the singularity of general relativity the infinitely tiny point at the beginning of our Cosmos is wrong it is simply assign that our mathematics is breaking down and we need a new understanding and that new understanding may even require rewriting the definition of time itself our conception of the univers unverse includes not just particles and radiation not just forces and interactions but the very fabric of SpaceTime itself of course we can Envision a beginning to space an imaginary spark that allows space to manifest and unfold itself becoming the universe as we see it but the beginning of time how can there be cause and effect before the existence of Time how can the clock of our universe start before there was a clock the beginning of the universe includes every feature of it including time itself so we can push the beginning of our universe beyond the edge of the big bang into the realm of Eternal inflation and the string landscape but even in these most advanced and hypothetical ideas there is still a start still a beginning still a time at which time begins if this sounds like a paradox it&#39;s because it is there is much about time that we currently do not understand and may never understand so what can we do our conceptions of time in physics are already muddled and contradictory in quantum mechanics time is treated as an external parameter a fact of the universe that uniformly marches forward allowing observers to make observations and for interactions to take place whereas in general relativity time is fluid relative and tied into space through a harmonious fabric to understand the universe we must reconcile these perspectives very simply we cannot speak confidently about a moment before time until we can understand with confidence what time exactly is and so for now our thoughts on space and time aren&#39;t sophisticated enough to Grapple with the beginning of it all because terms like begin are so rooted in our biological existence so grounded in our fundamental conscious perspectives on the world around us that we may not be able to escape our biases even when we extend them to the farthest reaches of our most advanced theories indeed the very process of time the segregation of the past present and future may break down in the early Universe conditions may become so extreme that the separation between before and after may lose all meaning caus ity may become a jumbled mess in the earliest moments of the cosmos moments may be [Music] meaningless this means it may ultimately be fruitless to search for an ultimate beginning a before the Big Bang because time itself at least the way we currently grasp it would become a useless framework for organizing the universe and yet even if we could surmount all these difficulties that would still not be the end because no matter what no matter which Theory we propose to explain our own Origins whether an infinite chain of multiverses or colliding brains or an endless cycle of repeated Big Bangs there is still something rather than nothing there is still physics there are still rules laws and ordered Harmony that allow for the existence of the cosmos if it&#39;s inflation then there&#39;s a Quantum field if it&#39;s colliding brains or a landscape then it&#39;s strings if its Loop quantum gravity then its discrete units of SpaceTime and our voyages into the horizons beyond the beginning of the Big Bang will undoubtedly reveal even more rules more structures more laws that allow for the creation of laws and so whatever we find there a fundamental reason that reality exists and is may just be forever Beyond us you&#39;ve been watching the entire history of the universe don&#39;t forget to like And subscribe and leave us a comment to tell us what you think thanks for watching and we&#39;ll see you next time

Transcript for:Exploring Big Bang Misconceptions and Theories

Transcript for:
Exploring Big Bang Misconceptions and Theories