StarTalk Podcast: Cosmic Queries – Multiverse Madness with Max Tegmark

[Music] this is star talk i'm your host neil degrasse tyson your personal astrophysicist and this is going to be a cosmic aquarius edition the ever popular format that we started many years ago and it just keeps going strong uh and today's topic is going to be the multiverse i got with me my co-host chuck hey neil how are you chuck nice you know you're getting such a schooling here with all this cosmic knowledge yes we have to give you a degree of your own no no no because then that that you know normally once you get the degree that means that your time at the institution is over unless you start paying more money okay so they kick you out the front door right okay so i'm just going to continue to i'm just staying at school forever that's a lifelong learner that's it just stay in school well this topic is in part celebration for the release of the second start talk book and guess what that book is called chuck um let me take a stab at it could it possibly be cosmic queries cosmic queries inspired by this very format and they're questions that people just ask that are so deep and so interesting and not all of them can we get to it on a podcast and so we have to like take it to the book and so there's a whole section in that book on the multiverse nice yeah yeah and i learned almost everything i know about the multiverse from our guest today and that is the one and the only max tegmark max welcome back i mean i've had you i've had you in other events at the museum for hayden planetarium um panels and things it's just always good to know you're in arms reach of us thank you but you know you just said something dubious you said the one and only max peg mark and if you take the multiverse seriously i'm not the one and only damn i just got schooled on my first sentence but max we go way back i mean when you were at the institute for advanced study and i was postdocking at princeton i think that's when i first met you and i followed your career it's been a brilliant melange of topics that are just so interesting and and the multiverse is the least among them that i have found interesting in your career so we'll have to have you back for other topics for sure plus chuck wow that is that is a serious compliment if if you know what i mean if the universe is a side it's a game multiple universes are the least interesting thing like i'm sorry i'm leveling with you here wow to be honest guys it has been especially my side gig all along just so i wouldn't tank my career with it because like when i was a grad student i was already fascinated by this but nobody else seemed to be and it was generally considered a bit too fringe so i played the multiverse very close to my chest and i didn't even i even wrote some papers when i was a grad student i didn't show my advisor until after he had signed my phd thesis under a pseudonym john doe yes okay oh that's so funny and it's so weird how now gradually some of these topics have actually come in a bit from the cold and gone from being just um considered career ending to being things that consider legitimate scientific controversies that we actually talk about openly at physics conferences so you're a professor of physics at mit of course the massachusetts institute of technology basically up the street in cambridge massachusetts and and uh chuck i've always been jealous of this man's name it's like movie star max tegmark it is starring it does it's you know it it it could be either the star of the show or the producer this is a max ted mark introductions yeah it works it works either way although all of all the above right and and max you've got a couple of books under your belt at least uh one of my favorites is our mathematical universe where you argue that everything is math and if everything is math someone could have programmed it that way and so a brilliant exercise there and of course life 3.0 um where you're exploring the future of what we even think of as life and i've enjoyed both of those books so thanks for i think of them as a gift to civilization to share in how you think about this world and i enjoyed the conversation that i heard on npr about your book about about mathematical universe okay but now we have the guy we got him ourselves exactly we'll have to share him so actually i just have to ask you a trivia question that i changed the name of that book in the last second for reasons we're going to talk about now the first title was the mathematical universe and then i thought that's so arrogant if we really believe that there are other universes we shouldn't just say the universe our ours we should talk about be more humble and acknowledge that it might just that our universe might not be the only one okay all right so it's just like so we went through a brief last-minute title change so that you wouldn't sound like an a-hole right we used to talk about the solar system and then we realized oops there are others right yeah or or the universe and i'm we're not saying that anymore it's our universe i don't like that yeah it's it's a good it's a good shift for that you change the universe into the humble verse that's cool ooh humble verse very good chuck making up words on the spot for humility in general i think homo sapiens yeah well yeah it's so max tell me what motivated people to you and your you know either you early on when you were doing this sort of under the cover of night to what is now mainstream research on the multiverse what motivated it well i think first of all throughout human history you know we've had this epiphany again and again that hey stuff is bigger than we thought and we you know we used to go in it to it with this hubristic assumption that all we knew about what was all there was kind of like an ostrich with the head of the sound and then people realized by the way the corollary to it's bigger than we thought is we're littler than we thought exactly we realized actually flip side of that coin we're part of this huge we're standing on this huge round ball in space which in turn is just part of this gigantic solar system part of the galaxy part of a cluster of galaxies part of the supercluster part of this that we then would call our universe and and uh you know why stop there so people started wondering could there be still more and the earliest people got into much more trouble you know than i ever did in grad school like giordano bruno 400 years ago started talking about how maybe space went on forever and you know what happened to him right yeah he was burned at the stake upside down with a with a something plugged into his mouth wow so that even in death he could not repeat these heresies wow talk about that they drove a stake into his mouth so that even when he died you know you know that's what i liked about that time the overkill overkill everything was overkill so you know now you know i went to campo de fiore actually in rome where this happened and i started to think you know compared to that that just getting burned on the job market there's a lot less of a threat so we're making some progress and it's a little bit of progress but just to be clear that square that uh in in italy there is in all fairness there is a statue to him where he's looking very solemn but it's a very honorific statue in his memory yeah it is absolutely smart small consolation for being burned at the stake and uh you know i'll take life you keep your statue is that what you're telling thank you thank you exactly but but you asked this very good question what drove us to these things and it's basically just uh natural logical steps it's just you know euclid himself postulated that space as infinites right when and when we were kids and we started wondering does this space go on forever it seemed pretty natural that there wouldn't just be an end to it right so if you just take that idea logically then that means that the part we can see right this is finite because light has only reached us from the spherical region that it could get here from during the 13.8 billion years since our big bang so if that's what we call our universe then by definition there are others other regions of space just as big just as cool and uh it's sort of hard to dismiss right now we don't i don't have a single astrophysics colleague anymore i think space magically ends right at that edge and in fact you can just wait one day and you see some more light arriving from farther away right and then and then so that's what i call the level one multiverse just other regions of space that we haven't had any access to well so initially it wasn't that people were motivated to try to answer some other question they just more fully explored what we were already thinking and already knew to be true about the universe so in that sense it's not some epiphany it's just an extension of what we're already thinking is that a fair way to think about your level one multiverse i think so and i think a lot of the pushback honestly wasn't really based on science so much but based on arrogant hubris you know the reason pope urban viii or whatever was so pissed at galileo you know wasn't because he had a good scientific argument but he would like we were so stuck to the idea that we everything cir orbits around us you know we humans are so important and we didn't like to be demoted to just being an average planet and an average solar system orbiting a galaxy et cetera et cetera and i think we see still a little bit of that today some people argue that they don't like this idea of reality being even bigger just because it makes their egos feel even smaller after the last four years i i can't imagine that people would actually have hold to those sentiments all right so uh what i don't know because i haven't quizzed people is what are they thinking of when they hear multiverse and my sense is they're thinking it's maybe a parallel universe that you might be able to to sort of move between at some distant future time uh so is there any truth to the concept of a parallel universe in the way it's commonly thought of in the public is there an evil chuck somewhere except with a goatee oh you already have a goatee is there a clean shaven you are the evil chuck chuck oh my god you're a good chuck oh my god that's right just think that through what's incredibly confusing here is that different people mean different things when they say universe and they mean they're talking about different kinds of uh and in fact i remember once very vividly martin reese had organized a conference in his house about these forbidden topics and i just heard chuck these are kind of friends we have that you get that you know you get invited for tea and you solve the issues of the universe okay you know this was considered pretty taboo back then but because martin was organizing it people still came and behaved and but i noticed that two people were arguing about the multiverse and i realized they're talking past each other one guy was talking about what we call the inflationary multiverse which is just really big space and we can get back to that another guy was talking about the quantum multiverse and they thought they were talking about the same thing so i felt i have i stood up and said hey wait a minute aren't there actually three different no four different kinds of multiverse that we should give different names to to not confuse ourselves so much and then i wrote that up and and the book you men mentioned so what i call first of all our universe isn't all of space it's just this part of space but just to be clear the book that you're talking about is uh you you post you posted something it's online which is a very clean and clear exposition of the multiple levels of the multiverse and that's what we referenced when we included when we fleshed out our section on the multiverse in cosmic query so i just want to be clear that you know you're not just pulling this out of your ass this is you've thought about this for a long time so so i think it's very important to just yeah be clear on what we're talking about yeah thank you so if by our universe we mean what astronomers call our observable universe there's just a spherical region of space from which light has reaches then what i call the level one multiverse is just other parts of space that are so far away that light hasn't reached us yet level two multiverse is what you get if you take seriously alan guth and andre linde and others and the theory of inflation that made our space so big which says that far far away in the same space now you have something much more diverse than you might have thought well even um the number of different kind of quarks could be different or the sort of forces that are different then we can talk about why and then there's this third kind and that's what gets more into the parallel evil feeling thing which has to do with studying not the big but the very small studying quantum mechanics where you can argue and people love arguing about that at physics conferences that in some sense our reality feels like it's splitting out into parallel branches and that's the whole if that is true you can tap into that weirdness by building quantum computers and then finally there's the fourth one which is so weird that almost nobody except myself believe in it which is the biggest and i think all of this is basically russian dolls they're nested they're all inside of each other right you start with our universe many of those that's level one many of those that makes level two many of those makes level three and many of those makes the ultimate one the the fourth level so these are these are these are multiverses of multiverses that's right that's right but the only one that ever gets any real attention is that kind of you know um tree limb version that you put pic that you depicted this splintering uh well you know where there's so many different uh infinite paths that are separate yet existing simultaneously that seems to be the one that captures the imagination of every sci-fi writer and and even rick and morty which is like a hugely popular show i mean it's like it's it's you know it because i think you could do so much with it you know there's an infant number of ricks and they're all geniuses so they you know so i mean you have an unlimited uh um reservoir of stories to tell chuck chuck max is rick we're gonna take a quick break when we come back we'll go straight into our questions from our patreon members when star talk cosmic queries returns we're back cosmic queries the multiverse edition and and uh max we've got max tegmark professor physics from mit i've known him for 25 years and no longer 30 years i think and yeah yeah yeah in every universe in every universe thank you chuck for clarifying that uh i'd max you into so many things uh into ai into most recently you've been thinking about news and the biases and news we have to get a whole other show on that one um but i just love the work you're doing it's fun to follow you uh from afar and so we've got you on this program to talk about the multiverse because that's one of your many expertise and chuck you've got questions for us let's do it okay let's just jump right into uh all the questions that we have taken from our patreon patrons the people who support us uh out of their substance to keep our show going so thank you guys for your support and if you uh are listening to this and you want to be a patreon member go to patreon.comtalk and uh and give us some support and maybe i'll reach her maybe maybe i don't know that's how you're going to end this yeah yeah maybe i'll figure it out maybe i'll think about reading you no of course i'm joking of course i'll read your letter and i'll push you your name no doubt okay no doubt here we go give it to me all right this is eric gross he says hello fellow earthicans uh said fellow eric because that's my middle name oh ericans oh yes either way can you explain the mind-boggling idea of infinite infinities oh wow wow wow that's a great question how about this wait so max let's let's let's start simple and let me ask you what does it mean for one infinity to be bigger than another and then let's take it from that into that directly into the quest let's drive the truck right into that question one inch wait a minute guys give me one sec wait what chuck great questions i gotta get this little pipe here you know if we're going to talk about one infinity being bigger than another i'm just saying i need to i need to be prepared the pipe has to be right there okay exactly if you have a pile of oranges and you have a pile of apples and you want to know is it the same number of apples as oranges the way you do it is if you can pair up each apple with exactly one orange you say the two numbers are the same so now play that game with infinities and weird stuff happens um let me for example you might think that there are more numbers one two three four five then there are even numbers you know two four six but they're actually the same because you can pair them up i can pair up one with two i can pair up eight with 16 i pair up every number with one that's twice as big which is always even so it's very counter-intuitive so for a while mathematicians start but just to be clear you just said something but not everyone knows this yeah max that twice any number any whole number is always an even number thanks for clarifying yeah yeah that is always the case so you can't take twice anything and end up twice a whole number and get an odd number so when you say twice the number that's always even that's a that's a fundamental fact about mathematics okay that's right and actually the quite weird conclusion is that some infinities which intuitively would seem like they're much bigger are actually all the same size and some mathematicians start to think maybe all infinities are the same size but then george cantor came along and said no there are some infinities they're even bigger and he's proved famously that the number of real numbers like 3.1415 with infinitely many decimals that they're actually more of those than the numbers you can count and after that people have realized that there's this whole tower of infinity so what that what's that got to do with parallel universes and this question well it's got a lot to do actually with the level one and the level two multiverse because chuck has to take a toke [Laughter] took break yes exactly so far this is great this is great take a deep breath because i'm going to tell you one of the things that i find the weirdest this is one of the weirdest things i believe to be true and if max finds it weird brace yourself right exactly that it is actually impossible it is according to einstein's theory of general relativity possible to take a little piece of space just finite and inside of there make an infinite space that doesn't stick out anywhere and actually infinitely and make many different infinite spaces inside of this finite thing it's a bit like the ending of the men in black i don't want to spoil it for those who haven't seen the film the movie around long enough don't worry about it so so alan guth andre linde and others came up with this most popular theory we have so far for what put the bang into our big bang right and made this expanding uh universe of ours starting with something tinier than an atom it's very very big and the ultimate party trick is inside of this tiny region they can not only make one space which when you live in it in feels infinite that's the level one multiverse for you in there so it has room for infinitely many of our universes but you can have infinitely many of those within there and uh so you can have an infinite number of infinitely large universes in a finite universe basically that's why it feels so utterly weird and the way that general relativity kind of pulls this trick is because even though it was a finite volume of space it has an infinite amount of future time to play with and it keeps stretching the space and then general relativity has this funny thing where it can kind of mix up space and time so that for someone who lives inside this what they consider to be space was something that you might have considered a little bit of time and i don't want to get too nerdy about this but you know einstein told us that what really we should only now are you saying you don't want to get too nerdy this only just occurred to you now i think you already blew it but einstein told us right that we shouldn't think of reality as a three-dimensional place or stuff happens but rather as a time being just a four dimension fourth dimension and this never changing place called space time so if like if if life is a movie then uh space time is the whole dvd and basically because you have this infinite future time to mess with if you can sort of bend your definition of what space is in there this is how alan gooth and andre linde and alex willinkin and others have have demonstrated this apparently crazy thing that maybe everything we see here in infinity of infinities could actually ultimately be emerging inside of this little bubble so just to clarify your dvd analogy what you're saying is we live as prisoners of the present transitioning from our past to our future so we experience a moment in time and many places in space but if you have the whole dvd of the movie then your entire timeline is manifest in that place all at once all at once all the time of your life is in that dvd you can have random access to it if you have if you can move throughout the time coordinate is that fair reference to how you use the concept of dvd it is it is and yeah that's right einstein even told some of his friends that they shouldn't worry about much about his death because he argued that it's just from the space-time perspective an illusion it's not like because i'm already dead man it's so are you we're all dead man and we're not i haven't even been born yet man and i'm dead what it's pretty weird chuck i mean i'm sure sometimes people come up to you when they're lost and ask hey excuse me but uh where am i right but they never come and ask when am i right in colloquial english we treat time as a very different sort of thing as space whereas when we say what's the time that's actually very arrogant just like talking about the universe or the solar system the what is the time i mean that that's saying that somehow the the instant when we're having this experience is the only time i mean all the other times past and present in space time have just as much claim to be real they certainly felt real to people who had experiences then right so if we want to be a little bit more rigorous we should always go ask people excuse me when am i what you are right now at this particular time having having this experience wow okay so that doesn't have the arrogance that it otherwise would yeah by asking what is the time i mean it's like going up and saying what is the place right of course where i am is the only place all right chuck give me some more questions all right well that was way too way to kick things off that is something else all right let's move on to uh you know this that that other level you talk about this is chris hampton could the parallel universe theory and the multiverse theory be combined for example we are living in a universe with billions of other organisms but what if each organism in the universe is itself a universe on a relative scale each one thus containing billions of organism so on and so on so he's taking your nesting doll and breaking it all the way down to every single organism right but yeah he's thinking um i mean i so so max if we have as a lead into that the early concept of the atom where people said oh my gosh atoms have structure and there's a nucleus and there's electrons orbiting so that's just like the solar system so maybe it's like turtles all the way down so how do we go from any understanding of scales of if everything's just on a different scale rather than something that's a completely different universe unto itself yeah very good question we see of course in nature this really beautiful hierarchy right you have some some quarks stuck together into neutrons and protons they're stuck together into this bit thing we call it nucleus stuck together in an atom and then you can make molecules and cells and you can make neil degrasse tyson and this society and the planet and galaxy et cetera what's different about the hierarchy of universes is is uh it's not just that the hierarchy exists but by definition i like to define the universe our universe as everything that we could possibly have any access to with unlimited funding and never mind other stuff that's in the way right so if you are if you look at for example if you're once if you're one person in a society there are a lot of people you haven't met but you could in principle meet them so they're not part of another universe you could in principle go to uruguay even if you've never been there right but you can never go 100 billion light years in that direction even if you wanted to it's it's just off limits to you so we're a bit more that's basically the definition i think is helpful about universe um and uh some people otherwise we'd use the term sort of poetically or metaphorically like the cell is a universe unto itself yeah you know so i think that's fair poetically but you're saying from the world of physics no that's not how we use the term yeah exactly and i mean it's whatever we need to have we should have a word for everything we can access it's very important for us especially in the future both if we're curious that's the limits of what we can observe and if we're ambitious that's also setting roughly the limits of where we could ever go in the future so if you don't want to call it universe call it schmooniverse or make up another word for it but it deserves to be called something right and which where space i think is a word that's better used to actually describe all of space and it's not the same thing space is probably bigger than our universe but we have confirmed that chuck lives in the schmooniverse just yeah it's clear the smoother verses it's where all dismissive people live universe schmooniverse what happened it could at least be the universe or the two i i don't mind a tuna verse now you're making me hungry uh well chris hampton actually uh it looks like he from what you just said is speaking of smoking it's that whole hey man there's a universe in my thumbnail like that whole vibe that's that seems to be where he's right all right cool so let's uh by the way again that was reminiscent of the ending of men in black with the galaxy on the belt of orion which was the tag line there but yeah you got to see the movie but it is you i like what you said neil the reason people use it poetically in that sense is because we think we refer things poetically as a universe unto its own basically if it really is doing its own thing and not interacting with the rest right which is what we're trying to capture scientifically here okay so now i should i i gotta i wanna ask my own question but i don't wanna i don't wanna take up these people's time chuck are you a patreon member if not shut the hell up and read the next question okay well neil i got to tell you you have bested me sir that was a damn good point oh my god hold on now i gotta go online right now i gotta get on patreon right now so i can ask my question all right here we go this is uh oh man you really got me with that one okay this is curtis um curtis lee uh zeidel hack uh i think uh yeah he says um first and foremost for formers my name is pronunce zado hawk okay so i okay i was wrong but i got it close conceptually i do not really understand how a multiverse affects our universe what is the most important effect on our universe and i'm going to paraphrase that and say is there any observational evidence right that such a thing exists and we're going to get to that in the next segment we've got to take a quick break cliffhanger so when we come back more star talk cosmic queries with my long time friend and colleague multiverse assist max tegmark on star talk we're back star talk cosmic queries multiverse edition or is it the shmultyverse we're trying to figure out creative naming of these things i got max tag mark max are you on social media um tag mark on twitter tag mark there you go nice the only tech mark in the world that's it that doesn't even need a first let just tag mark like well he's like you believe in the multiverse then there's undoubtedly some other planet out there with someone who looks exactly like me and talks like me but the first one you come to will probably be named schmegmark or something else because you know it's if you take seriously this idea that space is just infinite and started out a little bit differently in different places it's much more likely to get someone who is kind of sort of like me but not exactly right okay there you go well i mean in the in the meantime uh uh that's not a problem for twitter there's that scene where they have the whole room of a million monkeys typing away on a typewriter trying to get the works of shakespeare and so they finally get one it was just like to be or not to shrink the wreck yeah you know there's about a google particles you have to put together right in our observable universe so one with a hundred zeros so you actually have to try about a google plex times which is one with a google zeros after it until you get it right which is why your nearest clone might be ridiculously far away so i love the question you just asked before we got cut off there about what's the evidence for this is this just silly uh pub uh beer speculation or is there is this science did chuck who asked that that would be curtis uh zyto hawk yeah he's wondering do we feel see this other universe and so another the official way to say that is do we have experimental evidence that they exist right or this is just what you talk about at the at the beer halls yeah so it's a really great question because by definition of the what you mean by uh universe you are not affected by things outside of it so isn't that by definition untestable and the interesting thing is no that's not true first of all if you just take the theory that space is actually much bigger than we thought and with more stuff in it right if that's false that would mean that actually things kind of end at exactly the edge that we can see now that's very testable you just wait a little bit and then light from farther away reaches you and keeps coming into view and so we've already falsified that many times over now there's a more profound way in which you can test this also though we have to remember in science right we test theories and for theory to be testable you don't have to be able to test everything that it predicts just at least one thing take einstein it's theory of general relativity right it predicts all sorts of stuff that we can observe like how mercury orbits around the sun in a lot different way than people thought it was supposed to because of newton um we can test that we can test how light is bent by gravity et cetera but it also predicts what happens inside of black holes which you know very well we cannot go and observe but then come back and tell our friends about it why do we still take it seriously what happens inside black holes because we've this theory of general relativity has passed so many other tests that we could test that we also start taking seriously its untestable predictions and you can't just do say well i know i kind of like what einstein's theory predicts for the motion of mercury and gravitational lensing and yada yada yada but i don't like the interior black holes i'm just gonna opt out of that like if i go to starbucks and say i want my coffee but i'm going to opt out of the caffeine and have decaf that's not the way science works if you if you want to opt out of the black holes then go come up with your own gravitational theory which doesn't have black holes in it but still succeeds in everything einstein's theory did that turns out to be such a tall order that despite a lot of smart people trying you know for 100 years they've all failed so so what's that got to do with the multiverse well replace general relativity now with the theory of inflation with that we talked about it makes a bunch of testable predictions it predicts that our universe should be expanding that it should be very uniform but just to be clear you're not you're not actually replacing general relativity you're enclosing it yeah in the in inflation isn't that correct correct yes thank you for correcting me we take generativity and then we add and it's some additional assumptions to it that there's a certain kind of substance there which behaves in a certain way and then we do the math and it predicts all sorts of things that we've tested now successfully with great prediction like these ripples in the microwave background their statistical patterns for example i've worked as you know a lot on on trying to rule out this theory of inflation and i've failed and because of that we take it seriously and we also have to then take seriously the things inflation predicts that we cannot test such as that space is actually way bigger than our universe so there you go i think that's an excellent excellent way to think about it so so if the one theory has these multiple consequences it's okay if some of them you'll nev you can't or you never will if the ones that you can test turn out to be correct and you say if this is correct i'm going to take a stronger look over i'm going to start thinking about this by the way is it fair to say max that if you explore the things you cannot measure you might come up with a discovery that you can measure very true too because very often when people have been going off and thinking about these things which they knew they could never test they came it led them to ask questions what led them back back to a whole fresh way good test so that's a another very good reason not just we shouldn't think of these cool things just because they're fun but they often turn out to be very useful people started thinking about what the ultimate building blocks of matter were and atoms and so on and people for a long time thought that was completely useless but then by thinking about that they invented quantum mechanics which gave us the whole com computer technology which lets us have this podcast now and so on and that that's uh so and that's another example actually of exactly this this same question the quantum parallel universe is of course we can't visit them either but quantum mechanics predict so much else that we can test and it turned out to be very very difficult to come up with a theory of physics that predicts only some sort of creation mechanism for our universe that creates only the part we can see and then stops and doesn't make anything more so let me ask you this with respect to what you're saying chuck you're not a patreon member yet maybe you signed up during the break that's right you never know what i did during the break i don't know what you did during the break that's right all right i'll let you slip one and go all right so max with respect to what you just said are there things that we are able to observe or at least able to observe the forces thereof that remain a mystery that may in some way be attached to the multiverse theory i would say is that what we just answered is that are you saying chuck if the multiverse is what it is is there some piece of a dangling and visible in our own universe yes that we're observing that that but what we're actually observing but it's still a mystery like you know are there mysteries that aren't that are observable that i got to chuck i'm going to read i'm going to read i'm going to recast your question you're ready chuck okay are there deep mysteries in our own universe that could themselves be evidence of a multiverse and we have yet to put the two together how's that that's what i'm saying okay that's not what you said you you mentioned it but i didn't mangle it enough that you didn't know what i was saying and i will answer it with a resounding yes okay take dark energy for example we all know by now that we have no clue what 95 of our universe is made of and most of it is made of this weird stuff called dark energy and what's really odd about it is when you work when you work out exactly how much there is there is in the sort of most natural units of measurement that we would do in physics we get this number which is 0.00000 with 123 zeros and then a one and we wonder like why is that it turns out if you look closer that if you have a little bit more we would all be dead it wouldn't be any galaxies actually ever formed and if you had less so this was a bit negative we would be inside of a black hole by now and also not having this conversation so why is it that our universe was so fine-tuned that the amount of dark energy was dialed into this that very special value that let us have this conversation that is one of the exact those mysteries chuck i think that you're fishing for here we me some people said well tough luck sometimes we're just lucky let's just be grateful for it and shut up other people said maybe this is evidence that we were designed either by a divine being or by some simulator who tuned our universe especially to be able to have life in the parents basement they did this yes and then but then if you actually have para apparently this thing with space being very big with parallel universes with all sorts of different values of that knob setting in different places suddenly you have an actual simple explanation for this the picture you get then is that the bigger space is like the sahara desert it's mostly just the barren wasteland with no galaxies but in a few places you know that knob is set just right and you have an oasis where there is life and there are galaxies and there is star talk you know and surprise surprise of course that's where we're going to be having these conversations so but just to be clear it's not that it was set that way it's that if you have an infinite or a huge number of these universes where the knobs are set at random right one of those random knob settings will be the right combination for us it's like tuning tuning your dial up up and down what used to be radio kids there used to be a thing it used to be this thing called radio guys where you would actually tune your dial and like most of it was just white noise and empty but every once in a while you will come across somebody talking or some music or something like that exactly oh that is freaking brilliant god i love science okay okay keep going all right here we go here we go we've got just a few minutes left see if we can squeeze them all in go all right all right here we go um he's this is woody okay i'm going to read this because he's just going did you pronounce his name correctly that yeah okay i got it right what he says what are your thoughts on how a multiverse could actually begin what each one require big bang and how many of those would end up with a chuck being possible the chucker burst whatever yes so max does everyone have a big bang just like us that's a great question yeah so i've actually had a total rethink about the big bang concept because first i was taught that that's the beginning and now it's pretty clear if you take inflation theory seriously you should think of the big bang just as the end of this crazy creative inflation process in our little part of space when things calm down enough that you can make galaxies involve a kneel and a chuck and other in other places it kind of keeps going and so even if you have only one bang but that it keeps going ad infinitum you will end up having many many different regions where it stops and and you get what we recall a level one multiverse you know with the universe so all it takes is ultimately one bang to get it all and and if you have each one of those places where it stops being actually infinite then no matter how unlikely it is that you chuck a rise because the particles started out in exactly the right configurations for your mom to meet your dad and all of that the probability wasn't zero because it happened here and you're rolling the dice infinitely many times now right so it's guaranteed well there you go and by the way both my parents lost on that bet so on the roll of that dice i mean with by making you is that what you're saying okay all right believe me i was not a good kid all right keep it going here we go uh this is cameron bishop hello max hello neil i've always been curious is it flawed to ask what's between these universes is that measurable space that's a great question so between the different level one multiverses in the level two multiverse there's still space but that space in between is still doing this inflation thing and doubling its size over and over and over ago and in regular intervals that's why it's impenetrable because if you start flying through you go for a while and now you're still farther away from where you're supposed to go it's expanding faster than you can gain distance through it exactly exponentially okay that's great that's super cool all right okay here we go wait but in the quantum multiverse they're actually whole other space times there's not one space-time system right you have a quantum multiverse the level three lives in the bigger space we call hilbert space which may even have infinitely many dimensions so i hear the rents they're out of control the hilbert's favorite yeah property values are just off the charts something has to be done about hillberg damn it so but so what would you call what was between those quantum universes yeah in the quantum case it's much more tricky that when quantum mechanics was first invented people didn't know about this this phenomena called decoherence it was only discovered by hans dieter say in 1970 and he should be more famous than he is which is a kind of censorship mechanism that explains why we don't experience all those other weird quantum realities if they're actually there basically what comes out of the math is that these quantum superpositions as they're called they only survive as long as they're kept secret and whenever something gets really big you know air molecules bounce off photons bounce off and the secret is out it's like you tell a friend they tell a friend and so on and that's why big things like us always seem to only be in one place at once and we can only experience and measure quantum weirdness with tiny things that can keep their properties secret there's a chuck time for that last toke on that pipe yeah man i'm telling you right there that's wow that was that was cool what's it called d what now the coherence d coherence what he's saying is that we're so big we can only be in one place wow he's chuck when your kids are babbling on and you don't know what they're saying say stop being d coherent yeah don't be d coherent okay quantum dummy that's worse than incoherent you are g coherent yeah they're just de-cohering the whole conversation okay chuck give me one last question and see if max has a sound bite in him to answer because that's all the time we have left for it all right all right all right all right here we go this is j hunt greetings neil and max uh this is jeff from titan my question is to tighten the moon of the saturn i guess you gotta love that right my question is that means it's full of methane gas just so you know okay gotta cut down on those beans man yeah watch out for the beans right guys on this show you better be careful where you say you're from because otherwise there you go all right okay he says is a new multiverse created every time we make a this or that decision so the idea that the infinite number of possibilities are not actually possibilities until we make one of those possibilities fantastic question about the level three reminder about soundbite go on yeah yeah sliding doors movie watch it uh basically if you make a snap decision that you're really torn about right what ends up happening might come down to the position of a single little calcium ion somewhere in some synaptic junction and where depending on where it is off the things go and you end up with a completely different pattern either you decide to say yes to that date and live happily ever after or say no and do something different right so that can a micro superposition can get amplified into something that's so different macroscopically that this decoherence thing comes along and makes these two things really really separate so in that sense yes when you make a decision that really could have made both ways you are in a sense according to if the level 3 multiverse is real creating two parallel realities are equally real and each one of you is only of course aware of one outcome and is going to think that's all that happened oh my god oh that is crazy i love that that is awesome oh my god oh right now somewhere it means you created another chuck but you're only this chuck and so that's all you need that other that other guy is actually happy and he's having fun i try to think about that every time i get a parking ticket you know that there's some other power universe where i didn't but then i think a bit more and realized there's another final universe where i got towed max we got to call it quits there it's been a delight to have you on um it's always great to talk to you and probe your brain for all the fun stuff that you're thinking about and we'll get you on for another show because i there's more to you than what showed up here and i want to make sure our audience knows all about it so thanks for being on star talk chuck always good to have you always a pleasure all right this has been star talk cosmic query the multiverse edition neil degrasse tyson bidding to keep [Music]

Channel: StarTalk

Views: 413,447

Keywords: startalk, star talk, startalk radio, neil degrasse tyson, neil tyson, science, space, astrophysics, astronomy, podcast, space podcast, science podcast, astronomy podcast, niel degrasse tyson, physics

Id: d3uLw2gNMyo

Length: 49min 0sec (2940 seconds)

Published: Thu Mar 25 2021