Speaker 1: Hey, Jorge, are you a hoarder or do you like
Speaker 1: to throw things away? We keep everything, we have, every drawing,
Speaker 1: my kids ever made. Man, not me. I value space
Speaker 1: more than stuff. I love to throw things away. Wow,
Speaker 1: what does your family give you for your birthday? Then?
Speaker 1: Empty space? Actually, my wife rent a dumpster and says
Speaker 1: I can throw out anything I want. It's like a
Speaker 1: negative present. Hey, space is precious. You know you can't
Speaker 1: have too much of it. You can't have too much
Speaker 1: nothing said nobody never, Nothing is better than nothing. This
Speaker 1: is the best nothing I ever got. Hi more handmade
Speaker 1: cartoonists and the creator of PhD comics. Hi. I'm Daniel,
Speaker 1: I'm a particle physicist and I really do love space.
Speaker 1: And Welcome to our podcast. Daniel and Jorge explain the
Speaker 1: university production of I Heart Radio, in which we explore
Speaker 1: all the stuff in space, empty space, not so empty space,
Speaker 1: space builled with really crazy bonk, or stuff that's hard
Speaker 1: to understand, and sometimes even the very nature of space.
Speaker 1: We talk about all of these things in this podcast,
Speaker 1: and we break them down, and our goal is to
Speaker 1: deliver them to you in a way that actually makes sense,
Speaker 1: so you go away thinking, huh, I get it, or
Speaker 1: at least I get it as much as scientists get it,
Speaker 1: which sometimes isn't that much. And sometimes it feels like
Speaker 1: we're talking about a whole lot of nothing, and sometimes
Speaker 1: we are literally talking about nothing, and sometimes we're trying
Speaker 1: to figure out what is nothing exactly right. Yeah, deep questions, now, Daniel,
Speaker 1: when you say you love space, do you mean like
Speaker 1: you love, you know, just space travel, like where the
Speaker 1: planets are, or did you just like, you know, having
Speaker 1: the idea of space in your life. I love all
Speaker 1: of it. I love outer space, I love deep space.
Speaker 1: I live near space. I also love having space in
Speaker 1: my living room, Like it's not unusual for me to
Speaker 1: toss out a piece of furniture and go, you know what,
Speaker 1: the room is just better with nothing there. You like
Speaker 1: everything about space. There's nothing negative about space for you.
Speaker 1: I'm pretty pro space. Yeah. Absolutely, you would live in
Speaker 1: an empty box if you could, exactly. I'm like a
Speaker 1: cat that way. Are you looking forward and to your
Speaker 1: children leaving the house then, because that's just more space,
Speaker 1: is more space. I'm not looking for to them leaving,
Speaker 1: but if they do, I'm looking forward to throwing all
Speaker 1: their stuff away. Oh man, that's going to come back
Speaker 1: to want you. They're like, why did you throw away
Speaker 1: my comic book collection that's worth three million dollars? Now, yeah, exactly,
Speaker 1: but this space is priceless, right, Well, we like to
Speaker 1: talk about space in this podcast and also about what
Speaker 1: it represents, what it means, because it's kind of a
Speaker 1: topic that businesses don't have a super clear idea about.
Speaker 1: That's right. It's one of these really fun quite in
Speaker 1: physics because only recently did we figure out that it's
Speaker 1: a question that sort of has an answer. It's a
Speaker 1: question that's worth asking. It's one of these questions that's
Speaker 1: so basic that we just sort of assumed we knew
Speaker 1: the answer. You know, space is space. It's the nothing,
Speaker 1: it's the emptiness. And only recently have we realized, Wow,
Speaker 1: space could be much more than that, and it really
Speaker 1: deserves our attention. Right. Even more important is this sort
Speaker 1: of idea that maybe we don't need space, Like maybe
Speaker 1: it's just sort of like an add on to the universe. Yeah,
Speaker 1: is it at the foundation of reality or is it
Speaker 1: just something that fills up something else? You know, imagine
Speaker 1: what it would have been like to be a person
Speaker 1: ten thousand years ago. You never would have experienced reality
Speaker 1: without air, for example, So the concept of like a vacuum,
Speaker 1: a place where there was no air would have been
Speaker 1: totally alien to you. So now, of course we know
Speaker 1: that that's possible. It seems obvious that air is not
Speaker 1: a fundamental property of the universe. But we're at the
Speaker 1: next level and wondering, like, well, is space fundamental? Could
Speaker 1: you take it apart? Do you really need it? Yeah?
Speaker 1: In fact, so the universe, it doesn't have any air
Speaker 1: in it, right, most of the universe is pretty empty. Yeah,
Speaker 1: from that point of view, exactly, we were dealing with
Speaker 1: a very unrepresentative example. And we do this all the
Speaker 1: time in science. We assume that the things we experience
Speaker 1: our universal and we can generalize from these examples to
Speaker 1: the whole universe. We're doing this all the time, left
Speaker 1: and right without even realizing it. So now we're asking
Speaker 1: a similar question about space. You know, our our assumptions
Speaker 1: about space valid. Can we break it apart? Do we
Speaker 1: even need it? Is it possible for it to have
Speaker 1: bubbled up from something else? Yeah, it's a space topic.
Speaker 1: But space is pretty empty. I think we have a
Speaker 1: whole podcast episode about that, right, Like, what's the average
Speaker 1: density of the universe or like how much stuff is
Speaker 1: there really on a like cubic foot Yeah, we do
Speaker 1: have a whole podcast about how empty spaces and we
Speaker 1: take you on a journey from the top of the
Speaker 1: atmosphere into the Solar System and then out into interstellar
Speaker 1: space and then finally into intergalactic space. And mostly space
Speaker 1: is intergalactic space, right, Like there are these huge streams
Speaker 1: of galactic clusters of galaxies swinging around each other, but
Speaker 1: between them there are these vast bubbles and voids that
Speaker 1: don't have galaxies in them. So most of the universe
Speaker 1: sort of by volume, is this intergalactic space, which is
Speaker 1: not totally empty. There's still stuff in there. That's a
Speaker 1: little bit of dark matter, there's definitely dark energy. But
Speaker 1: it's most of the universe and it's pretty empty, but
Speaker 1: not down to zero. Yeah, and there's a lot of
Speaker 1: it space, I mean, in the universe, there's a whole
Speaker 1: bunch of it. Like if you are going at the
Speaker 1: speed of light, it would still take you as far
Speaker 1: as we know right now, you know, tens of billions
Speaker 1: of years just to go from one side to the other.
Speaker 1: That's a lot of time. Absolutely, And remember the speed
Speaker 1: of light is like mind boggling lee fast, right, It's
Speaker 1: incredibly fast. And yet these distances, even inside our Solar
Speaker 1: System are incredible, Like it takes minutes for light to
Speaker 1: get from here just to Mars, which is our neighbor,
Speaker 1: and hours to get out to the outer Solar system.
Speaker 1: You know, when we communicate with probes and rovers and
Speaker 1: stuff on other planets, the reason you can't drive them
Speaker 1: is because they are so far away. You can't do
Speaker 1: real time driving because the lag is too long. And
Speaker 1: that's just inside our Solar system. So the distances to
Speaker 1: other galaxies millions of light years and deeper into space
Speaker 1: billions of light years, they're hard for us to get
Speaker 1: our mind around. So, yeah, space is pretty spacious. I
Speaker 1: guess I hadn't thought about it before. Like if even
Speaker 1: if you're Superman or Superwoman and you're traveling, you can
Speaker 1: you're able to fly at the speed of light, it
Speaker 1: would still take you like a billion years just to
Speaker 1: you know, go to the other galaxies out there in
Speaker 1: the universe. Yeah, well that's an interesting question. Does Superman
Speaker 1: have to travel at the speed of light? Can he
Speaker 1: be superluminal? I mean, how far away is his home
Speaker 1: planet anyway, I don't know you're the physicist. I just
Speaker 1: read the comic books. I don't dissect them scientifically. I'll
Speaker 1: go find out exactly where his home planet is and
Speaker 1: figure out if he broke the law on the way here,
Speaker 1: and if so, I'll issue him a physics ticket. Well,
Speaker 1: he can just bring it up with his heat visioned Daniel.
Speaker 1: And also, how are you going to arrest him? Good
Speaker 1: luck with that, citizens arrest Mr Superman. But yeah, there's
Speaker 1: a lot of space out there. It's definitely not a
Speaker 1: small part of the universe. But I guess the question
Speaker 1: is it a necessary part of the universe. So today
Speaker 1: on the podcast, we'll be asking the question can the
Speaker 1: universe exist without space? Space? Space? Space space? That question
Speaker 1: is so profound it needs an echo. It echoes through
Speaker 1: the vacuum of infinity, through the vacuum of our understanding
Speaker 1: of the universe. Absolutely, through the empty space in my head.
Speaker 1: But it's a fun question, and it sort of mirrors
Speaker 1: the way I treat furniture. You know, I look around
Speaker 1: my house and I asked myself, do we need that chair?
Speaker 1: Nobody ever sits there and we get rid of it.
Speaker 1: We're like, ah, it's better off. And now we're cycling
Speaker 1: through modern physics and we're like, m, do we really
Speaker 1: need the whole concept of space? Like is it really
Speaker 1: have to be included in the sort of fundamental list
Speaker 1: of things you need to build a universe or is
Speaker 1: it like you know, ice cubes or atoms or hurricanes,
Speaker 1: something that you know comes from your more basic ingredients.
Speaker 1: I would hate to be a furniture in your house.
Speaker 1: I feel like I would live in constant fear. Yes, absolutely,
Speaker 1: you must constantly justify your existence in my house, or
Speaker 1: you're on the trashy. It's like huff Post reporters. You know,
Speaker 1: hopefully that's just for your furniture, not your family as well.
Speaker 1: Or pets. Absolutely, living creatures definitely belong to the family.
Speaker 1: Chairs not so much so if you could have a
Speaker 1: bigger house, would you have a bigger house? No? No,
Speaker 1: I don't need a bigger house. In fact, I had
Speaker 1: some friends who once moved to a bigger house and
Speaker 1: I almost ruin their marriage because they ended up shouting
Speaker 1: each other from different rooms across the house. And they
Speaker 1: did better when they had to, you know, share a
Speaker 1: small apartment. Yeah, we talked about this and I offered
Speaker 1: the better solution of just getting an intercom system. You
Speaker 1: are going to engineer everybody's marriage. Huh. I'm gonna go
Speaker 1: to your your couple's counseling. There's a solution for everything
Speaker 1: in engineering, marital engineering. Wow, that's a better name for therapist.
Speaker 1: But anyways, Yeah, it's a big question whether or not
Speaker 1: we need space in the universe. It seems pretty fundamental,
Speaker 1: you know, like, how can you have a universe without space? Like,
Speaker 1: isn't space the universe? Yeah, but just because it's hard
Speaker 1: to imagine doesn't mean it's not reality. Right. A lot
Speaker 1: of what reality is was difficult for us to wrap
Speaker 1: our minds around. So when you do this kind of exploration,
Speaker 1: you got to sort of be willing to give up
Speaker 1: something you thought was fundamental, something you assumed was inherent,
Speaker 1: and ask your question whether it can come from something else.
Speaker 1: All right, Well, as usual, we were wondering how many
Speaker 1: people out there have thought about this spacious question, whether
Speaker 1: or not we need space. So Daniel went out there
Speaker 1: into the well to the internet to ask people is
Speaker 1: it possible to have a universe without space. Here's what
Speaker 1: they had to say. Oh, that's a good question. I
Speaker 1: don't think, so okay, why, Well, I don't know. I
Speaker 1: don't know. I don't know. I don't know why. I
Speaker 1: just know I think space is only one of the dimensions, right,
Speaker 1: you can probably have a universe. It's just time and
Speaker 1: maybe not space. I'm gonna say yes. Well, my understanding
Speaker 1: is that, yeah, I guess you can. Um. I mean,
Speaker 1: was this space when the Big Bang occurred in the
Speaker 1: moments after that, or was it all dense metal with
Speaker 1: zero space? But my understanding is that if you have
Speaker 1: a different universe that could operate off a completely different
Speaker 1: set of physical laws. So I guess never say never
Speaker 1: in that regard. You can have a universe without space.
Speaker 1: Our situation with matter having out competed antimatter, I think
Speaker 1: is actually pretty unique. Um there, and I would I
Speaker 1: think they're a little universe blips all over where universe
Speaker 1: pops into existence and annihilates and no spaces created. I
Speaker 1: guess you can have universe with out just this dimension space,
Speaker 1: and you can have all the other dimensions possible, but
Speaker 1: it will be crowded. I guess it would mean what
Speaker 1: you mean by universe, because before the Big Bang all
Speaker 1: the universe was there. It was just compressed and to
Speaker 1: my knowledge, there was no space. So if you can't
Speaker 1: that just the universe then yeah, all right, some mixed
Speaker 1: reactions here. Some people could live without it, some people
Speaker 1: could really want it. Yeah. It basically wraps up the
Speaker 1: whole question of what spaces and where it comes from
Speaker 1: and all these answers I see echoes of general relativity
Speaker 1: and quantum mechanical perspectives on this question. So good job listeners,
Speaker 1: And to those of you who would like to participate
Speaker 1: in future rounds of answer random questions for the podcast,
Speaker 1: please write to us two questions at Daniel and Jorge
Speaker 1: dot com. There's a lot of reference here and the
Speaker 1: answers to the Big Bang to write that's something I
Speaker 1: hadn't thought about before. Was their space before the Big Bang?
Speaker 1: At the Big Bang? Or was space created at some
Speaker 1: point in the history of the universe? Yeah, space and time? Right,
Speaker 1: all right, Well, let's dig into it, Daniel. Let's start
Speaker 1: with maybe the basic stuff, like what is space? How
Speaker 1: do physicists think about what space is? Yeah, this is
Speaker 1: a great question, and we have sort of two answers
Speaker 1: for what space is based on whether you're thinking about
Speaker 1: it from the point of view of like quantum mechanics
Speaker 1: or whether you're thinking about it from the point of
Speaker 1: view of general relativity. And remember that these are the
Speaker 1: two pillars of thinking in modern physics, too great ways
Speaker 1: to describe parts of the experiments we've done. Quantum Mechanics
Speaker 1: describes basically everything that has to do with little particles
Speaker 1: at small scales and all the forces that were familiar
Speaker 1: with except for gravity, and general relativity talks about how
Speaker 1: space is curved and it's bent, and that's really what
Speaker 1: gravity is. And so the answer to the question what
Speaker 1: is space sort of depends on whose perspective you want
Speaker 1: to take first? What do you mean, how can something
Speaker 1: depend on your perspective? Aren't you looking for like one answer?
Speaker 1: We are absolutely looking for one answer, but we don't
Speaker 1: have one answer. We have two theories, quantum mechanics and
Speaker 1: general relativity. They treat space very differently and we haven't
Speaker 1: been able to unify them. So the short answer is
Speaker 1: we don't know what space is because we don't have
Speaker 1: a single coherent theory for the whole universe, and the
Speaker 1: two theories we do have disagree about what space is,
Speaker 1: all right, So what are the two theories about space?
Speaker 1: And is there enough space between them to tell the difference. Well,
Speaker 1: you know, let's start with quantum mechanics. Quantum mechanics is
Speaker 1: the theory that tells us how electromagnetism works, how the
Speaker 1: weak force works, you know, how photons move, and it
Speaker 1: tells us that space is fundamental. It assumes that space
Speaker 1: exists and it adds stuff to it. So if you're
Speaker 1: gonna build a universe using at least our current theory
Speaker 1: of quantum mechanics, then you start from space. You say,
Speaker 1: let's assume there's a space, and then at every point
Speaker 1: in that space, I'm gonna say whether or not there's
Speaker 1: a quantum field and how much energy it has. But
Speaker 1: it's sort of like at the bedrock of the whole theory,
Speaker 1: just like assuming that space and time are things that
Speaker 1: you can put fields in them, right, because that's kind
Speaker 1: of baked into the definition of a field, right, Like
Speaker 1: you can't have a field without space, like a field
Speaker 1: is by definition like how things vary in a space.
Speaker 1: That's right exactly. And we'll talk later about whether you
Speaker 1: can generalize that to like abstract spaces rather than physical
Speaker 1: spaces and what that means. But you're right for the
Speaker 1: physical fields that we're talking about, you know, like the
Speaker 1: photon field. It's just a value all through space. But
Speaker 1: as you say, space is fundamental to that. You need
Speaker 1: to know like there's a certain value of field here
Speaker 1: and over there at a different location in space, it
Speaker 1: has a different value. And for example, the shrouding your
Speaker 1: equation tells us how a wave function exists across space,
Speaker 1: and how that wave function evolves through time it spreads
Speaker 1: out through space, for example. So it's pretty deeply baked in.
Speaker 1: So quantum field theory sort of the modern version of it,
Speaker 1: as we think about it, doesn't really have an answer
Speaker 1: to the question of what is space. It just sort
Speaker 1: of like assumes it exists and starts from there. It's
Speaker 1: like the basical list of ingredients. Would you say then
Speaker 1: that maybe quantum fields defined space or do you think
Speaker 1: space could exist without quantum fields. Well, that's a great question.
Speaker 1: In our current theory, you can't have space without quantum fields,
Speaker 1: Like quantum fields filled the entire universe. There's no sense
Speaker 1: in which you could have space without them. That's just
Speaker 1: sort of according to the theory. But do they define space?
Speaker 1: I think they're deeply coupled to it. Yeah, absolutely, so
Speaker 1: I think it's definitely part of the inherent nature of
Speaker 1: space in quantum field theory that you have these fields
Speaker 1: that live on top of it. But remember that quantum
Speaker 1: field theory can also have stuff in it that doesn't
Speaker 1: sort of come into the very beginning, right, Like we
Speaker 1: can talk about the very basic ingredients of the universe,
Speaker 1: space and quantum fields, but we don't add to that
Speaker 1: things like you know the atom, right, The atom is
Speaker 1: not a required element of the definition of the universe.
Speaker 1: It comes from that other stuff. So the ad and
Speaker 1: we think it exists, but it's not like fundamental. And
Speaker 1: remember the goal of physics, as you say, is to
Speaker 1: come to one theory, one explanation, one most basic list
Speaker 1: of ingredients and the rules for combining them that then
Speaker 1: explains everything else. So we're constantly trying to throw stuff
Speaker 1: out on purpose so we can get like the minimal
Speaker 1: list of fundamental things that can then explain everything else.
Speaker 1: As emergent. We want to explain ice cream and atoms
Speaker 1: and hurricanes in terms of the simpler, more basic elements.
Speaker 1: Do you guys want the dumpster then too, so you
Speaker 1: can throw out theories. I definitely want to throw space
Speaker 1: out on the physics dumpster. I would love to explain
Speaker 1: space in terms of something more basic and fundamental and say, man,
Speaker 1: remember when we had space criming in here and we
Speaker 1: had no space because we had so much space. But
Speaker 1: then if there's no space, then there's no space in
Speaker 1: the dumpster either, Daniel, where would you throw it out? Oh? Man,
Speaker 1: I'll get a bigger dumpster, all right, So then that's
Speaker 1: quantum mechanics. But then general relativity has a different view
Speaker 1: of space. Yeah, General relativity tells us that space is
Speaker 1: not something which is just like inherent and that you
Speaker 1: can assume. General relativity tells us that space is really different.
Speaker 1: It's dynamical. It's not like the backdrop for everything. Instead,
Speaker 1: it's in this dance with matter. Right. When you have
Speaker 1: matter and energy around, space bends and it curves, and
Speaker 1: it can do weird things like it can ripple, right,
Speaker 1: and it can expand. And this is the things that
Speaker 1: we see, like we see ripples in space. We know
Speaker 1: that this general relativity picture is at least approximately correct.
Speaker 1: It might not be the fundamental theory of the universe,
Speaker 1: but it's really accurate. It predicts these gravitational waves and
Speaker 1: we see them. It can accommodate at least the accelerated
Speaker 1: expansion of the universe in terms of a cosmological constant.
Speaker 1: We don't understand why that's there, what's happening, etcetera, but
Speaker 1: it can be accommodated in general relativity. So it's very
Speaker 1: successful description of how matter and space interact. And it
Speaker 1: suggests that space is not fundamental, that it sort of
Speaker 1: states at the same level as matter our energy, because
Speaker 1: the too sort of have this feedback loop between each other.
Speaker 1: Basically says that space is a thing, right like, it's
Speaker 1: not static, it doesn't exist, it doesn't ignore matter, you know,
Speaker 1: like it responds to matter, and you know, it's not
Speaker 1: independent of matter exactly. And you can do these weird
Speaker 1: things that we never imagined that it could do, which
Speaker 1: means it might be able to do other weird things
Speaker 1: we also hadn't yet had the imagination to do. Anytime,
Speaker 1: we're limited by our imagination. I'm always skeptical that we've
Speaker 1: thought of everything. I know, the theorists are very smart,
Speaker 1: and even our science fiction authors are always pushing the
Speaker 1: boundaries of creativity when it comes to like, you know,
Speaker 1: intellectual concepts. But there's always the possibility that there's always
Speaker 1: something else out there we just haven't thought of that
Speaker 1: could be happening in our universe. So space could have
Speaker 1: really weird properties that we never imagined. Imagine, for example,
Speaker 1: being a scientist that's a fish swimming through water all
Speaker 1: the time and not realizing, you know, that space could end,
Speaker 1: or that your water wasn't actually fundamental, and they could
Speaker 1: do other weird things like boil and turn into a gas.
Speaker 1: You know, space like that could have other phases, other
Speaker 1: weird properties we just haven't observed yet, and so we
Speaker 1: assume are impossible because I guess, once you can get
Speaker 1: space to bend or ripple or expand then who knows
Speaker 1: what you can make it do? Who knows what you
Speaker 1: can make it do exactly? And the solutions to general
Speaker 1: relativity are so complicated and difficult, and that it's not
Speaker 1: possible to conceive of all the possible configurations that are
Speaker 1: consistent with it. Those are the two views of space.
Speaker 1: One says that it's something that you know, can't touch
Speaker 1: or that you live on top of, and the other
Speaker 1: one says that it's something that it's more of a thing,
Speaker 1: like it's dynamic and you can manipulate it and it
Speaker 1: can change, So that those are the two basic views
Speaker 1: about space, right, But it doesn't sort of explain what
Speaker 1: space is. It's just sort of like how you regard space. Yeah,
Speaker 1: but that's sort of what space is. You know, space
Speaker 1: is how we treat it. Some people might say space
Speaker 1: is just like a mathematical construct in our minds. You know,
Speaker 1: that's not actually something that's physical. For example, in quantum mechanics,
Speaker 1: we never deal with space itself directly, right, All we
Speaker 1: ever do is deal with the fields in space. We
Speaker 1: never like interact with space itself, and so it's sort
Speaker 1: of like just an abstraction. It's just like a way
Speaker 1: of thinking about organizing these fields. Whereas in general relativity,
Speaker 1: like spaces the thing. It's the thing that's keeping us
Speaker 1: on the Earth. It explains gravity, which is pretty important.
Speaker 1: So you know, how we represent them in our theories
Speaker 1: goes a long way to telling you what we think
Speaker 1: they are. All right, Well, I think that sets the
Speaker 1: space for a deeper discussion about space and whether or
Speaker 1: not Daniel can through it in the dumpster or not.
Speaker 1: Please please please, please, please please please. I would be
Speaker 1: so offended if I was space right now, I would
Speaker 1: limit your space Daniel. But let's get into that question
Speaker 1: and also whether or not we will ever be able
Speaker 1: to know what the answer is. But first, let's take
Speaker 1: a quick break. All right, we're talking about space and
Speaker 1: whether or not we can just toss it out, Daniel,
Speaker 1: I feel like that's so unappreciative. How can you just
Speaker 1: throw the thing out that you know you grew up in. Well,
Speaker 1: you know, let's make a distinction here. We are, of
Speaker 1: course searching to explain space, to figure out whether it's
Speaker 1: the basic ingredient of the universe or whether it emerges
Speaker 1: from something else. But that's not to say the things
Speaker 1: that emerge are uninteresting or unimportant. Right, Like, the entire
Speaker 1: field of biology is emergent in the sense that you could,
Speaker 1: in principle, calculated all from fundamental particles. But that's not
Speaker 1: like a smart way to do biology. Nobody would anybody
Speaker 1: does do biology from the particle perspective. I just want
Speaker 1: to make sure people don't think that we're being negative
Speaker 1: about emergent phenomena. They're fascinating, they're amazing, they're incredible. We
Speaker 1: are emergent phenomena. It's just, you know, part of this
Speaker 1: question of getting down, drilling down to the deepest nature
Speaker 1: of reality is to ask what's fundamental and what's emergent,
Speaker 1: not necessarily to judge them. You just want to add
Speaker 1: your bets and not offend your spouse's biologist. I have
Speaker 1: the deepest of respects for my spouse and also for biology,
Speaker 1: which is not your furniture. Just not my furniture, absolutely
Speaker 1: all right. So there are two perspectives about space. It
Speaker 1: seems like quantum mechanics doesn't say anything about space other
Speaker 1: than it's there and you can't mess with it, and
Speaker 1: general relativity says that it's something that you can sort
Speaker 1: of mess with and change and bend. And I guess
Speaker 1: the question is are those two things incompatible or is
Speaker 1: there a sort of a fundamental conflict about them? Like
Speaker 1: couldn't you have quantum mechanics sit on top of general relativity? Yeah, exactly,
Speaker 1: And people are working on exactly that, trying to unify
Speaker 1: general relativity and quantum mechanics in several different ways, and
Speaker 1: in doing so, they're giving us hints about answers to
Speaker 1: this question about whether space is fundamental or not. Like
Speaker 1: when they put these two things together, they basically have
Speaker 1: to make a decision like, well, do we have spaces
Speaker 1: the list of fundamental ingredients in our new theory of
Speaker 1: quantum gravity or not. And there's a couple of different approaches.
Speaker 1: One is sort of like make gravity a quantum theory,
Speaker 1: thinking about it as like just another quantum force that
Speaker 1: exchanges particles the gravitons in order to make gravity happen,
Speaker 1: and sort of making quantum mechanics primary. And the other
Speaker 1: is to try to quantize gravity itself, you know, either
Speaker 1: make the universe into little pixels or take the gravitational
Speaker 1: field and make a discreet and so that would make
Speaker 1: a general relativity sort of at the primary foundational level
Speaker 1: of these new theories of quantum gravity, and which direction
Speaker 1: you go sort of dictates the fate of the idea
Speaker 1: of space and whether it's fundamental or emergent. I guess
Speaker 1: maybe one difference is that like in general relativity, if
Speaker 1: you have a speck of dust, it's technically bending the
Speaker 1: space around it. But in quantum mechanics, if you have
Speaker 1: like a proton or an electron, it's not really bending
Speaker 1: space around it. Right, In quantum mechanics, we have no
Speaker 1: description of the curvature of space that works, right, So yeah, absolutely,
Speaker 1: we don't have a quantum mechanical description of gravity or
Speaker 1: the bending of space, so we can't describe how space
Speaker 1: has bent around of dust particle. We know that it
Speaker 1: is though, right we think that that's true. One of
Speaker 1: the difficulties is that we can't test these things very
Speaker 1: well because particles have very very small amounts of gravity.
Speaker 1: Member gravity so much weaker than all the other forces,
Speaker 1: like ten to the thirty times weaker. So we can't
Speaker 1: really test these things because all the other forces dominate.
Speaker 1: Two protons, for example, coming together, the large Hage and
Speaker 1: collider feel almost no gravity in comparison to the strong
Speaker 1: and the weak and the electromagnetic forces, So it's very
Speaker 1: hard to do an experiment at the particle level that
Speaker 1: tests gravity. I guess maybe then to get back to
Speaker 1: our question, then what do these two theories say about
Speaker 1: the idea of having no space? Like could you have
Speaker 1: no space in plantum mechanics or general relativity or is
Speaker 1: that impossible according to the theories. So there are now
Speaker 1: really fun ideas about how space might not be fundamental,
Speaker 1: how you could have a universe without space in quantum mechanics.
Speaker 1: And I think these ideas are really cool because they
Speaker 1: make us think about quantum mechanics sort of at a
Speaker 1: more basic level. You know, we think about the wave function.
Speaker 1: For example. Wave function is like this basic element of
Speaker 1: quantum mechanics. It tells you what's going to happen to
Speaker 1: a particle, or for example, where a particle might be.
Speaker 1: If you have a question about the outcome of your experiment,
Speaker 1: the wave function tells you this outcome has a certain probability,
Speaker 1: and that outcome has another probability. And typically we think
Speaker 1: about the wave function as distributed across space, like is
Speaker 1: the electron here or is the electron there, But in
Speaker 1: principle it can be distributed across abstract states also, you know,
Speaker 1: like the electron spin or the outcome of your experiment,
Speaker 1: or all sorts of other kinds of things. And so
Speaker 1: it's not hard for us to sort of augment the
Speaker 1: current concept of space with these like abstract spaces. We
Speaker 1: call them Hilbert spaces in which the wave function lives.
Speaker 1: And it might be that those Hilbert spaces are the
Speaker 1: actual primary thing that we can sort of let go
Speaker 1: of these concepts of position and based the whole existence
Speaker 1: of the universe just on those sort of abstract spaces
Speaker 1: than the ones that are not physical, that don't represent
Speaker 1: actual locations, that are not anywhere. I think what you're
Speaker 1: saying is that, like maybe space, according to the theory,
Speaker 1: is not like a physical thing or physical space, but
Speaker 1: it's rather just sort of like a mathematical concept or
Speaker 1: set of relationships. Is that what you mean. Yeah, we
Speaker 1: know that it's a set of relationships. As we said earlier,
Speaker 1: in quantum mechanics, we never actually interact with space. All
Speaker 1: we do is we see sort of the propagation of
Speaker 1: information through fields as that information moves through space. But
Speaker 1: really that information is moving through the field, and so
Speaker 1: you can think about it in terms of like pieces
Speaker 1: of space that are sort of woven together. So it's
Speaker 1: like the relationships between different elements of the field, and
Speaker 1: the space itself is really just like the relationship between
Speaker 1: those elements. So this one is far away from that one,
Speaker 1: or this one is close to that one. So you
Speaker 1: don't have to have those bits of the field like
Speaker 1: hanging in an absolute, actually existing space. It might just
Speaker 1: be that they have those relationships in another way and
Speaker 1: woven together that gives the same effect as if they
Speaker 1: were actually in a space. I wonder if it's sort
Speaker 1: of like the concept of money. You know, like something
Speaker 1: is worth more or has a bigger price on it
Speaker 1: just because it doesn't mean that it has more energy
Speaker 1: to it or more matter to it, or you know,
Speaker 1: sits closer to you, or you can do more things
Speaker 1: with it. It's just so happens that this thing has
Speaker 1: a labeled with a big price on it, and that
Speaker 1: that one has a labeled with a lower price on it.
Speaker 1: Is that kind of what you mean, Like, maybe space
Speaker 1: is really just like the economy of the yeah, exactly.
Speaker 1: And you can also think about it in terms of
Speaker 1: like your networks. Think about your relationships with your family.
Speaker 1: Who are you close to We even use that word close, right,
Speaker 1: Even if you're physically far away from somebody else, you
Speaker 1: have a network of people that you interact with who
Speaker 1: know you very well, and then people who are distant,
Speaker 1: and then people who are basically super impossibly far away. Well,
Speaker 1: it might be that that sort of like the fundamental
Speaker 1: definition of who you are and what your spaces rather
Speaker 1: than like where you actually are sitting in your bedroom
Speaker 1: or in Los Angeles or in Germany or wherever. Maybe
Speaker 1: space is just an emotional space, you know what I mean?
Speaker 1: Like space is really just the emotional currency of your relationships. Yeah,
Speaker 1: and these are just analogies we're using to try to
Speaker 1: get your mind away from this primacy of space that
Speaker 1: we've been assuming and thinking about the universe as built
Speaker 1: out of things that don't hang in space but still
Speaker 1: have relationships with each other, and then those relationships are
Speaker 1: what space emerges from. And we can actually do this
Speaker 1: not just by doing analogies to social media, but actually mathematically,
Speaker 1: and people have taken the way function of the universe.
Speaker 1: For example, think about, like what is a quantum mechanical
Speaker 1: description of the whole universe? Can you describe everything in
Speaker 1: the universe and you don't have to necessarily put them
Speaker 1: in a location, you know, just say there's a probability
Speaker 1: for this particle and probably for that particle, and then
Speaker 1: link them together and say, well, this one is entangled
Speaker 1: that one. This concept of quantum entanglement of particles having
Speaker 1: like their fates connected to each other because they have
Speaker 1: a common past. This entanglement might provide that weave, It
Speaker 1: might provide the connection between like the bits of the
Speaker 1: universe that when you weave them together, some things are
Speaker 1: more entangled than others, and so they seem closer together,
Speaker 1: and other things are less entangled, and so they seem
Speaker 1: more distant. It might be that this quantum entanglement are
Speaker 1: those same relationships that connect these bits of the wave
Speaker 1: function that make it seem as if it is hanging
Speaker 1: in some space. And this sort of set of relationships
Speaker 1: or currency or valuations, that's what you call these Hilbert
Speaker 1: spaces or is that different? The Hilbert space is the
Speaker 1: set of possible wave functions that you can have, and
Speaker 1: then the relationships between the different wave functions that are disconnected,
Speaker 1: those are the entanglements. Those come together to make this
Speaker 1: sort of like grand weave that we call space. And
Speaker 1: if this is true, it doesn't mean that space is
Speaker 1: not like real. It just means that it comes from
Speaker 1: something else, you know, that it bubbles up from something
Speaker 1: more primary, just like air is real, even if it's
Speaker 1: not fundamental to the universe. You can still breathe it.
Speaker 1: It's still very nice on a nice, fresh windy day
Speaker 1: in Los Angeles. Come on, never happens. But I guess
Speaker 1: maybe a question is what's the difference? You know, like
Speaker 1: the word Hilbert space still has the word space in it,
Speaker 1: So like what would be the difference between a Hilbert
Speaker 1: space or these abstract connection space and maybe a more
Speaker 1: regular definition of space. Well, our four dimensional space has
Speaker 1: certain properties. You know, information transforms through it in a
Speaker 1: certain way. It follows the speed of light. There are
Speaker 1: four dimensions, including time. An abstract Hilbert space is much
Speaker 1: broader and more general, like it can be infinite dimensional.
Speaker 1: You can have complex values, you know, imaginary numbers, all
Speaker 1: sorts of things. So this is sort of like a
Speaker 1: subset of all the possible Hilbert spaces. It's like it
Speaker 1: turns out that the relationship between all these quantum wave
Speaker 1: functions can be described in this sort of simpler subspace,
Speaker 1: this four dimensional subspace, in which all that information can
Speaker 1: be mapped onto the whole hill of beans. It's the
Speaker 1: whole hill of beans. But it also means other interesting things.
Speaker 1: If this is true. It means that, for example, you
Speaker 1: could have different spaces inside this, like larger Hilbert space.
Speaker 1: You can have like our chunk of space which is
Speaker 1: all woven together, and you could have another one somewhere
Speaker 1: else was also emerged and is totally disconnected from ours,
Speaker 1: and you could have maybe parts of it without these relationships, right,
Speaker 1: Like you could have a whole bunch of people with
Speaker 1: no friends on Facebook exactly, or even parts of the
Speaker 1: world where there is no Facebook. Hard to imagine, right,
Speaker 1: but it might be true. And so if this picture
Speaker 1: is accurate, then the answer is absolutely you can have
Speaker 1: the universe without space. It's not necessarily clear that you
Speaker 1: need space to have the universe. And you can have
Speaker 1: parts of the universe with space, parts of the universe
Speaker 1: without space, and other parts of the universe you know
Speaker 1: that have different kinds of spaces. And you might be thinking,
Speaker 1: hold on, he's saying the word parts. What does he
Speaker 1: mean if there's no space, what parts is he talking about?
Speaker 1: And again, you know, these parts don't necessarily have like
Speaker 1: a spatial relationship. You can't say this one is here
Speaker 1: and that one is there in the sense of like
Speaker 1: where is your family? You know, you guys might be
Speaker 1: physically somewhere, but the actual relationships between you, those connections
Speaker 1: that tie you together, like where is that It isn't
Speaker 1: really anywhere, It just sort of in your emotional space. Yes,
Speaker 1: if you can't find your family, that's a whole different
Speaker 1: problem there, and a whole different type of podcast. There's
Speaker 1: the whole genre for that. But that's sort of the
Speaker 1: quantum mechanical view. If you say quantum mechanics is primary
Speaker 1: and the way function for the universe is the most
Speaker 1: basic thing, then can you build up a universe without spaces?
Speaker 1: Space necessary? That's the quantum mechanical path, right, And it
Speaker 1: sounds like the answer is sort of yes, Like if
Speaker 1: quantum mechanics is all there is, then it might be
Speaker 1: possible to see how you could not have space absolutely.
Speaker 1: And there's some really fun recent ideas things called like
Speaker 1: condensate cosmology, where space condenses in these like steam like
Speaker 1: droplets from these weird fun spin networks that are more fundamental,
Speaker 1: but we're gonna do a whole podcast about that sometime
Speaker 1: in the future. Well all right, well then, and now,
Speaker 1: what does general relativity say about not having any space?
Speaker 1: Is that possible? According to that view, general relativity really
Speaker 1: has no problem with space not existing because in our
Speaker 1: general relativistic understanding of the universe, think about what happens
Speaker 1: in the history, Right, we have the current universe. We
Speaker 1: look back in time and we see the universe getting
Speaker 1: more and more compact, and we propagate back and further
Speaker 1: and further and further and approaches this special moment, this singularity,
Speaker 1: this time before which space does not exist. And you know,
Speaker 1: there are various ideas for how to tackle that and
Speaker 1: what that means and if it's a breakdown of the
Speaker 1: theory and if it needs to be replaced by something else.
Speaker 1: But in our current albeit imperfect, non quantum mechanical general relativity,
Speaker 1: there is this concept that there is no space before
Speaker 1: the Big Bang, there's no space or it was just
Speaker 1: super compressed. It's super compressed in the very first moments
Speaker 1: of the universe, but before that, before the singularity itself, right,
Speaker 1: this moment of infinite density, that space did not exist.
Speaker 1: That it doesn't make sense to ask where is something
Speaker 1: or when is something because the whole notion of space
Speaker 1: and time came into existence then, like there is no
Speaker 1: space and time before then. And this is not something
Speaker 1: that's very easy to think about because we don't think
Speaker 1: about space and definitely not time beginning right, But a
Speaker 1: whole other podcast episode about whether you need time and
Speaker 1: if time is an emergent phenomena. It's a whole even
Speaker 1: more difficult question to grapple with because you have to
Speaker 1: think about, like, could there be a time before which
Speaker 1: there was no time. But putting that aside for the
Speaker 1: time being, at least, it's hard still to think about
Speaker 1: a universe existing without space. But if you can still
Speaker 1: have time, right, if you say time exists, but maybe
Speaker 1: space is not fundamental, it might make sense to you
Speaker 1: to think about like space itself is this weird thing
Speaker 1: we talked about, this weird do that does stuff, and
Speaker 1: it can bubble and it can expand. It's being created
Speaker 1: right now. If it's being created, then you know, maybe
Speaker 1: there was a moment before it was created, or you know,
Speaker 1: you can think about what is there when it's not
Speaker 1: being created right and there's there's no space, if there's
Speaker 1: no space being created exactly, and it might be that
Speaker 1: you can have a universe before space is created. Might
Speaker 1: be the time existed before the Big Bang, but just
Speaker 1: not space. And there's some like conditions required for space
Speaker 1: to be created for it to expand. Like you might
Speaker 1: think it's a weird concept for space to be created,
Speaker 1: but remember that it's happening right now. You know, the
Speaker 1: expansion of the universe is not the motion of stuff
Speaker 1: through the universe. It's the creation of new space between
Speaker 1: us and other galaxies, between you and your couch between
Speaker 1: everything and everything else. So it's happening right now. And
Speaker 1: it's just that we have only recently realized that space
Speaker 1: is this bizarre fabric that can do these things like
Speaker 1: be created spontaneously everywhere simultaneously, that we've come to ask
Speaker 1: these quests, and so we just really don't have a
Speaker 1: notion and understanding of what space is even in general relativity.
Speaker 1: But it's certainly is possible that it can be created.
Speaker 1: And so yeah, you can imagine there being a pre
Speaker 1: Big Bang moment when there was a universe but just
Speaker 1: no space. All right, Well, it sounds like both theories
Speaker 1: are pretty cool with the idea of not having space.
Speaker 1: They can both take it or leave it. Yeah, absolutely,
Speaker 1: variations of quantum mechanics can accommodate space not being fundamental
Speaker 1: even though our current quantum field theory sort of assumes
Speaker 1: that it's there. You can build these extensions that sort
Speaker 1: of make it possible for space to be emergent, for
Speaker 1: it to bubble up, rather than just being an assumed
Speaker 1: property of the universe. Alright, so space, take it or
Speaker 1: leave it? Leave it? All right, Let's get into how
Speaker 1: we would ever know if space is or not disposable
Speaker 1: or dispensable. But speaking of time, it's time to take
Speaker 1: another quick break, all right, Daniel. It sounds like physicists
Speaker 1: could take space or leave it. It sounds like both
Speaker 1: theories about the universe would be okay. They wouldn't break
Speaker 1: down if you suddenly got rid of space. Yeah. And
Speaker 1: I think if you took a survey of physicists right
Speaker 1: now and you ask them if space was fundamental or emergent,
Speaker 1: if it came from something else more fundamental, I bet
Speaker 1: you get like saying that it's an emergent, that it's
Speaker 1: not fundamental, that it's comes up from something else, which
Speaker 1: means that you could have a universe without it, or
Speaker 1: portions of the universe without it. I think that's the
Speaker 1: current mainstream thinking. And as we all know, the universe
Speaker 1: works democratically, so whatever the majority says must be true. No,
Speaker 1: we're definitely capable of being misled and having the wrong idea.
Speaker 1: But I think it's sort of exciting that it's widespread.
Speaker 1: It means that lots of people are working on it,
Speaker 1: People are developing new ways of thinking about these really
Speaker 1: really basic questions, and people out there also should be
Speaker 1: excited it means that, like we're just the beginning of
Speaker 1: asking questions about the universe and tackling them. If you
Speaker 1: are excited about questions like you know, what is the
Speaker 1: universe and where did they come from? And what's it
Speaker 1: really made out of? Remember that there are huge tracts
Speaker 1: of questions that are just really being explored by This
Speaker 1: is just now, and so there's plenty of room to
Speaker 1: make like really fundamental Einstein level discoveries about the nature
Speaker 1: of the universe. Right. I think what you're saying is
Speaker 1: that there's an electoral college in the universe, and who knows,
Speaker 1: who knows what the rules are for that? That's right. Fortunately,
Speaker 1: physics is easier to calculate than the electoral college. All right,
Speaker 1: I guess maybe now the big question is how would
Speaker 1: we know or not whether space is fundamental or whether
Speaker 1: or not it's like an add on or like an
Speaker 1: optional preference in the universe you could live in. Is
Speaker 1: there a way for us to test it because we
Speaker 1: live in this space that we're trying to test. Is
Speaker 1: it possible to I don't know, create an experiment where
Speaker 1: you have no space? Yeah, there's really two steps to that. First,
Speaker 1: is we gotta make more theoretical progress and then we
Speaker 1: got to do some experiments. So on the theoretical side,
Speaker 1: what we really need is a unification of quantum mechanics
Speaker 1: and general relativity. We need a theory of quantum gravity
Speaker 1: that tells us how the universe works, so that we
Speaker 1: can think about, like what is space, and this theory
Speaker 1: if it all hangs together and like does everything it
Speaker 1: has to do, meaning it can describe everything that gravity
Speaker 1: can do, and they can describe all the tiny fundamental
Speaker 1: particles and it brings those together in a way that
Speaker 1: makes sense that you know, they don't disagree with each
Speaker 1: other like the current quantum mechanics and general relativity do.
Speaker 1: Then we can ask questions of that theory. So first
Speaker 1: we've got to make progress. Theoretically, we need like an
Speaker 1: actual theory that totally works. Before the break, we talked
Speaker 1: about a few possibilities like directions people are going. These
Speaker 1: are like half formed ideas. People are like building scaffolding.
Speaker 1: You can see the outlines of a structure of people
Speaker 1: are trying to make work, but nobody has an actual
Speaker 1: functioning theory of quantum gravity where we can ask these
Speaker 1: kind of questions and get answers. I guess you need
Speaker 1: some sort of theory first, right, Like, you can't just
Speaker 1: take out space and measure it and not measure it.
Speaker 1: How do you measure not space? Well, we have done
Speaker 1: a lot of really cool experiments about space, right, Like
Speaker 1: seeing gravitational waves is incredible. It tells us that space
Speaker 1: really is sort of fungible and dynamic. And measuring the
Speaker 1: expansion of the universe that's also kind of an experiment
Speaker 1: that tells us what's going on with space. And a
Speaker 1: lot of times experiment informs us. Remember that we didn't
Speaker 1: expect the universe to be expanding in an accelerating manner
Speaker 1: until we saw it, and it totally shocked us and
Speaker 1: surprised us. So sometimes experiments can inform us. I think
Speaker 1: in this case, we really need theory to tell us,
Speaker 1: like how we can do experiments to answer this question,
Speaker 1: because currently the only experiments I can think of are
Speaker 1: ones that are like at the center of a black
Speaker 1: hole or requires super colliders the size of a solar system,
Speaker 1: not things we can get done tomorrow. No, exactly, because
Speaker 1: for example, general relativity and quantum mechanics they disagree about
Speaker 1: what's at the center of a black hole. You know,
Speaker 1: general relativity says, oh, there's a singularity there, but quantum
Speaker 1: mechanics says, you can't have a singularity because that's too
Speaker 1: much information isolated in one little spot and it violates
Speaker 1: the Heisenberg uncertainty principle. And so if you could see
Speaker 1: what was going on inside the black hole, you can
Speaker 1: get great clues as to how to build your theory
Speaker 1: of quantum gravity. Or if you could somehow do tests
Speaker 1: of particles feeling gravitational forces by building a super huge
Speaker 1: collider and smashing those particles together at crazy high energies
Speaker 1: enough energy where like gravity is as powerful as the
Speaker 1: other forces, that maybe you could get a clue as
Speaker 1: to how to build your theory of quantum gravity. But
Speaker 1: we can't do either of those experiments today, And so
Speaker 1: I think what we need is some inside from the
Speaker 1: theory to tell us, well, look, here's how the universe
Speaker 1: is put together. Here's our theory of what spaces, and
Speaker 1: this theory gives us a clue about how to look
Speaker 1: for evidence that the theory is correct. You know, there's
Speaker 1: some like wrinkles, some experiment we can predict the outcome
Speaker 1: of that can tell you whether or not this is right.
Speaker 1: It's like if only you can break the loss of
Speaker 1: physics so that you could figure out the laws of exactly.
Speaker 1: And there's maybe one more hint of something that we
Speaker 1: can do, which is that we can look for more
Speaker 1: evidence of this creation of space. We can look for
Speaker 1: evidence of those first moments just after the Big Bang
Speaker 1: and trying to find some gravitational radiation from the Big
Speaker 1: Bang itself. But what do you mean, like a shock wave,
Speaker 1: or like actual radiation, or like gravitons. Yes, exactly all
Speaker 1: of those things. You know that we have microwave background
Speaker 1: radiation from about four hundred thousand years after the Big Bang,
Speaker 1: when this hot plasma cooled and became transparent. We see
Speaker 1: those photons, and people often say that that radiation is
Speaker 1: like from the Big Bang itself. It's not quite as
Speaker 1: from you know, four hundred thousand years after the Big Bang,
Speaker 1: when the universe became transparent and that light is now
Speaker 1: still propagating around. We'd love to see earlier. We'd have
Speaker 1: to look further back to the actual creation of the universe,
Speaker 1: whatever happened there, And so it might be Passe will
Speaker 1: do that by looking for gravitational waves that were created
Speaker 1: in those very first moments when the universe was expanding
Speaker 1: so rapidly, we think that gravitational waves were made. So
Speaker 1: there's another kind of radiation called the cosmic gravitational background
Speaker 1: that might have clues as to what the nature of
Speaker 1: spaces and whether it was created in those first moments,
Speaker 1: if we could see it like the echoes of the
Speaker 1: creation of space, yes, exactly, and so we have theories
Speaker 1: about what that might look like under various configurations. And
Speaker 1: you might remember several years ago people didn't experiment where
Speaker 1: they thought they measured those waves. It was called BICEP two.
Speaker 1: But then it turns out that they were mistaken and
Speaker 1: they were actually just measuring dust between galaxies. So that
Speaker 1: was disappointing, But it might still be possible with a
Speaker 1: better round of experiments, more precision and control of that dust,
Speaker 1: to see the actual radiation from the early universe and
Speaker 1: get a glimmour as to whether space was created or
Speaker 1: whether it had always been there. And there's another possibility
Speaker 1: right us to whether or not we can confirm this
Speaker 1: existence or the tendency of space, and that is that
Speaker 1: maybe in the future there might not be any space.
Speaker 1: Right exactly, are we going to run out of space
Speaker 1: or are we just gonna, you know, get a victim
Speaker 1: from our house. No, you're absolutely right. And some of
Speaker 1: these theories of loop quantum gravity, for example, they predict
Speaker 1: that the universe's expansion will stop and it will turn
Speaker 1: around and it will compactify, so that space is like
Speaker 1: being destroyed instead of being created, and we'll have like
Speaker 1: a reverse big bang, this big crunch, And it's not
Speaker 1: clear what would happen after that. Would we get another
Speaker 1: big bang? Would we just have no space for a while?
Speaker 1: But does time even exist anymore? We don't know. So yeah,
Speaker 1: stick around another few trillion years and the question might
Speaker 1: just answer itself. Yeah, things might get a little bit
Speaker 1: more crowded or were space and cluttered? All right? Well,
Speaker 1: it sounds like it is possible for the universe to
Speaker 1: not have any space, But we may not find out
Speaker 1: any time, you know, unless we observe something incredible or
Speaker 1: we make a breakthrough in one of these theories that
Speaker 1: let us look or you know, kinks that we can
Speaker 1: use this evidence that space cannot exist. Yes, and I
Speaker 1: think that there will be theoretical progress. People are working
Speaker 1: really hard on this stuff. Black hole information paradox is
Speaker 1: giving us some clues. So there's a lot of really
Speaker 1: smart people working really hard on these questions, and I
Speaker 1: think in the next five or ten years we'll see
Speaker 1: some really clever, fascinating, mind blowing theories coming out to
Speaker 1: explain our bunkers universe. They just need a little space,
Speaker 1: you know, no pressure. All right, Well, we hope you
Speaker 1: enjoyed that discussion. Thanks for joining us, see you next time.
Speaker 1: Thanks for listening, and remember that Daniel and Jorge Explain
Speaker 1: the Universe is a production of I Heart Radio or
Speaker 1: more podcast from my heart Radio visit the I heart
Speaker 1: Radio app, Apple Podcasts, or wherever you listen to your
Speaker 1: favorite shows.