Speaker 1: Sometimes it drives me crazy thinking about the secrets that
Speaker 1: are buried in the past, you know, things that actually
Speaker 1: happened that we just don't know the institude. You mean,
Speaker 1: like who killed JFK. No, No, I'm thinking bigger, Like
Speaker 1: where are my socks after I put them in the dryer?
Speaker 1: That's a big mystery. But I'm thinking cosmic size mysteries.
Speaker 1: I mean, like who thought two introverts could make his
Speaker 1: science podcast? That's an enduring mystery for sure. But I'm
Speaker 1: talking about like universe size mysteries, you know, like, you know,
Speaker 1: the universe started in one way and no other way,
Speaker 1: And what if we could just go back to the
Speaker 1: past and watch it and and unearthed these mysteries from
Speaker 1: the past. Wouldn't that be amazing? What was it like
Speaker 1: as a baby? Basically? Right? Like, was it awkward? Cute? Funny? Tantramy? Hi,
Speaker 1: I'm Jorge. I'm the creator of PhD Comics, and I'm Daniel.
Speaker 1: I'm a particle physicist work at the Large Hadron Collider
Speaker 1: smashing particles together. And this is our podcast Daniel and
Speaker 1: Jorge Explain the Universe, where we trying to explain basically
Speaker 1: everything in the universe. In a way that makes sense
Speaker 1: to you everything the whole universe. Yeah, so to be
Speaker 1: on the program, we have the question what did the
Speaker 1: baby universe look like? That's right? What did the universe
Speaker 1: look like when it was really young, when it was
Speaker 1: just formed, or just after it got started to look
Speaker 1: totally different from today? Did it look basically like today?
Speaker 1: What did it look like? Daniel? What did you look
Speaker 1: like as a baby? I looked like a universe as
Speaker 1: a baby. Actually, oh good, that's better than me. I
Speaker 1: looked really different as a Maybe then I do now
Speaker 1: because I have one of these noses that grows sort
Speaker 1: of tectonically. So when I was a kid, I had
Speaker 1: a tiny, little button nose, and now I have sort
Speaker 1: of a very large alpine nose that just continues to
Speaker 1: grow through my lifetime. Well, that sounds better than me.
Speaker 1: I just looked like an old bald man. Did you
Speaker 1: look like Winston Churchill when you were born? I did
Speaker 1: a little bit. Actually, my father was named after Winston Churchill,
Speaker 1: which is which is a coincidence there. Okay, So the
Speaker 1: question today is what can we learn about the universe
Speaker 1: from its baby picture? What did the universe look like
Speaker 1: as a baby? Yeah, this is an interesting question because
Speaker 1: I was thinking the other day, you know, Daniel, how
Speaker 1: do you know that you were actually born? Like, how
Speaker 1: do you know that you were a baby? I mean
Speaker 1: you think I came out this size? Yeah? Basically, right, Like,
Speaker 1: how do you know how do you know you didn't
Speaker 1: just pop into existence when you were five years old
Speaker 1: or you know, like you were growing out of a
Speaker 1: test tube and then and then um and then extra
Speaker 1: rooted when you were five years old, which is when
Speaker 1: sort of your memories start to kick in. Right, extruded.
Speaker 1: That sounds like such a pleasant experience. I wasn't born,
Speaker 1: I was extruded. Technically we're all extruded. Yeah, but you're
Speaker 1: you're right. There's a there's a sort of a larger
Speaker 1: question there, which is like how do you know about
Speaker 1: yourself and your context and where you came from? And
Speaker 1: why is that important? Right? Like I might say to you, like,
Speaker 1: I don't know if I was born, you know, at ten,
Speaker 1: out of the laboratory and implanted with all these memories
Speaker 1: to make it feel like I had a childhood, But
Speaker 1: what does it matter? Right? You might say that it
Speaker 1: doesn't matter, but I think it does matter. I think
Speaker 1: it matters where we come from, what our context is,
Speaker 1: what our culture is. In the same way we wonder
Speaker 1: about larger things like how is the Earth made? Right?
Speaker 1: The Earth's baby picture looked like, how is the Earth extruded? Yeah,
Speaker 1: I guess I'm talking about like evidence, you know, Like, um,
Speaker 1: it's nice that I have there are pictures of me,
Speaker 1: or at least that I'm told it's me as a baby,
Speaker 1: so I can sort of trace my development. But if
Speaker 1: I didn't have those pictures, I might wonder did I
Speaker 1: just pop into existence when I was five? Right? And
Speaker 1: you can look at those pictures, and you can see
Speaker 1: things about yourself that, you know that tell you something
Speaker 1: about who you are, like to your old Jorges already
Speaker 1: holding a banana or already cracking silly jokes or you know,
Speaker 1: doodling on the wall or something. Their truths about you
Speaker 1: that are emerged early on. Right, Like, man, look at
Speaker 1: that cute baby. I can only imagine what the baby
Speaker 1: is going to grow up to be, Like, how did
Speaker 1: such a cute baby turn into this? You know, there's
Speaker 1: the mystery, right, there's awesome, magnificent specimen. Yeah, And I
Speaker 1: think that every time, for example, I see like an
Speaker 1: old time picture of my hometown. You know, I grew
Speaker 1: up in Los Almos, and they're all these pictures of
Speaker 1: what it looked like during World War Two, and you
Speaker 1: know that shaped the history of the town. And when
Speaker 1: I see these old pictures, I like saying, like, oh,
Speaker 1: look that building, I still recognize that it's an enduring feature.
Speaker 1: And all this is destroyed, it was just transient. So
Speaker 1: in the same way, I like thinking about the history
Speaker 1: of the universe because it teaches us something about how
Speaker 1: it was all put together, and you know what it all.
Speaker 1: You see things that make it and what it is
Speaker 1: like unique, make it, yeah, exactly special. Yeah, And it
Speaker 1: tells us a lot about what's happening in the future.
Speaker 1: You know, we want to know what's going to happen
Speaker 1: to the future because we're invested, we're going to live
Speaker 1: in it. Then we better look into the past. And
Speaker 1: you know, we've made startling discoveries by doing this. You know,
Speaker 1: the whole discovery of dark energy, the fact that the
Speaker 1: universe is being shredded apart by some massive, not understood energy,
Speaker 1: right that was only discovered by looking into the past
Speaker 1: and understanding what the universe used to look like. Right, yeah,
Speaker 1: baby talk aside, we're talking about the universe, right, and
Speaker 1: how can we tell what the universe was like, you know,
Speaker 1: not just a hundred years ago, two thousand years ago,
Speaker 1: but fourteen billion years ago? Yeah, exactly what did it
Speaker 1: look like? And what can we learn from that? So,
Speaker 1: as usually, we were curused to hear what people out
Speaker 1: there thought about this question, and so here's what they
Speaker 1: had to say. What do you think the early universe
Speaker 1: looked like? Um, the baby universe I would think would
Speaker 1: be something really compactly dnce in like probably in a
Speaker 1: circular looking thing. I would think, yeah, um, probably nothing
Speaker 1: in particular, just a bunch of gases and like crazy,
Speaker 1: maybe spirals. I don't know, like you know, not no
Speaker 1: stars or anything, that's for sure. I guess like a
Speaker 1: more extreme version of what it looks like now because
Speaker 1: everything was kind of more close even though it's expanding,
Speaker 1: so it's like, I know, there was less space in
Speaker 1: between everything, So I guess more bright and intense. I guess. Delete.
Speaker 1: On the program, we have astrophysicist Katie mac Hi. Katie, Hi,
Speaker 1: how are you good? So you're probably one of the
Speaker 1: most famous astrophysicists on the internet. Do you have a
Speaker 1: huge Twitter following, and uh, that's really cool. Thanks. Yeah,
Speaker 1: it's been really interesting. I don't know where all the
Speaker 1: people come from, but I'm glad that they are hanging
Speaker 1: out and listening to me talk about astrophysics. Can you
Speaker 1: tell us a little bit about where you work. I'm
Speaker 1: in the physics department at North Carolina State. I'm an
Speaker 1: assistant professor, and I'm also part of the Leadership in
Speaker 1: Public Science Cluster, which is a new initiative to encourage
Speaker 1: connection between scientists and the general public. Very cool. Yeah,
Speaker 1: And I think it's important for people that people to
Speaker 1: understand that you're not just somebody on Twitter who likes
Speaker 1: to talk about science, but you're actually a practicing scientist
Speaker 1: who's chipping away at the mysteries of the universe. Yeah.
Speaker 1: I'm doing the best I can at that. And your
Speaker 1: expertise is in um Yeah, So I do theoretical cosmology,
Speaker 1: which is the study of the universe from start to
Speaker 1: finish and the evolution of the universe and what's in it.
Speaker 1: And my area of specialty at the moment is dark matter.
Speaker 1: So I'm interested in what dark matter is and how
Speaker 1: it did what it did in the early universe and
Speaker 1: all of that, and I'm also interested in black holes
Speaker 1: and in the very early universe and the very end
Speaker 1: of the universe. What did you think about people's general
Speaker 1: knowledge of what the early universe is like? This surprise you.
Speaker 1: I think everybody kind of gets the idea that it
Speaker 1: was real, different than now and maybe not as structured um,
Speaker 1: and that the structure in the universe has come about
Speaker 1: over time, which is true. And so help the people
Speaker 1: out there understand that. How can we possibly know that?
Speaker 1: How do we know what the early universe looked like
Speaker 1: at all? We know what the early universe looks like
Speaker 1: because we can look right at it. We can actually
Speaker 1: see it. We can watch the Big Bang happening. And
Speaker 1: there's caveats to that in terms of what I mean
Speaker 1: when I say a big bang and what I mean,
Speaker 1: but when I say watch it happened. But the nature
Speaker 1: of the early universe is one of the most certain
Speaker 1: things we we have in cosmology because we can actually
Speaker 1: see it directly. So tell us what that means. Where
Speaker 1: do you look to see the Big Bang? Well, you
Speaker 1: look everywhere? Um, okay, so let me go back a
Speaker 1: couple of steps, billion steps. Yeah, yeah, yeah, Why do
Speaker 1: we even think there was a big bang? There was
Speaker 1: one guy who we talked to without the universe is
Speaker 1: like this forever. How do we know that's not true? Right?
Speaker 1: We know that the universe is changing with time because
Speaker 1: we can see that it's expanding UM. And the way
Speaker 1: we see it's expanding is that we look at really
Speaker 1: distant galaxies and we see that they all seem to
Speaker 1: be moving away from us. The whole universe is getting bigger,
Speaker 1: and so the spaces between all of the galaxies is
Speaker 1: getting bigger, and that means that every galaxy we see
Speaker 1: is going to look like it's moving away from us.
Speaker 1: And in fact, the more distant galaxy, the more quickly
Speaker 1: it seems to be moving away from us. And so
Speaker 1: you know, beyond a certain distance UM, when we get
Speaker 1: out into like the open universe, outside of our little
Speaker 1: local area, everything is moving apart. And that only makes
Speaker 1: sense if the universe is expanding, and if it's expanding
Speaker 1: like the same in every direction. So you can look
Speaker 1: at that and then you can say, well, if it's
Speaker 1: getting bigger than it was smaller in the past, and
Speaker 1: you can just kind of extrapolate back and say that
Speaker 1: there had to have been a time when everything was
Speaker 1: really really really close together. But that's sort of the
Speaker 1: question is like, what did things look like when they
Speaker 1: were are all sort of on top of each other,
Speaker 1: when the universe was that small? How do we know
Speaker 1: what it sort of looked like. If you have some
Speaker 1: kind of box with stuff in it, and then you
Speaker 1: make that box bigger than things get farther apart, it's
Speaker 1: sort of cools down because there's there's more space and
Speaker 1: things are not bumping into each other as much. And
Speaker 1: so if you go the other direction, then the early
Speaker 1: universe should have been a lot hotter and denser and
Speaker 1: you know, in some sense sort of smaller than it
Speaker 1: is now. And so because of that sort of extrapolation,
Speaker 1: a bunch of physicists um back in the day said, well,
Speaker 1: if that's the case, then all of that heat and
Speaker 1: radiation from the early universe should actually still be out
Speaker 1: there somewhere. Well why should it still be out there?
Speaker 1: I mean, wouldn't it have been absorbed or bounced around?
Speaker 1: Since then? What do you mean all that heat and radiation? Okay,
Speaker 1: so so this is where it gets a little bit
Speaker 1: trippy and complicated, But this is where it also gets
Speaker 1: really cool. I love trippy and complicated, but it's really
Speaker 1: cool because this is this is where we're actually seeing
Speaker 1: the Big Bang. Okay, so the speed of light is
Speaker 1: not infinite, which means that if you look at like
Speaker 1: the nearest star other than the Sun, you're looking at
Speaker 1: something that's four light years away roughly. That means that
Speaker 1: the light that you see from that star is four
Speaker 1: years old by the time it gets to you. So
Speaker 1: you're saying that to look into the past, you just
Speaker 1: have to look at things that are far away. Yeah, yeah, exactly,
Speaker 1: And so the farther away that you look, the farther
Speaker 1: in the past you're seeing. And we have telescopes where
Speaker 1: we can see galaxies where the light has been traveling
Speaker 1: for like thirteen billion years, you know, So we can
Speaker 1: actually see galaxies that are like some of the first
Speaker 1: galaxies ever formed in the universe. We can see really
Speaker 1: really early objects. If we just keep looking farther and
Speaker 1: farther away, then we're looking farther and farther back, and
Speaker 1: we're looking at a time when the universe was so
Speaker 1: hot and so dense that that part of the universe
Speaker 1: was on fire. Every part of the universe was like
Speaker 1: this sort of giant fireball. I mean, not are exactly,
Speaker 1: but like plasma, right, And so there's some part of
Speaker 1: the universe that's so far away that the last like
Speaker 1: a little bit of radiation from that fire has been
Speaker 1: sort of streaming through the universe just in every direction.
Speaker 1: And there's a part of the university so far away
Speaker 1: that that little bit of radiation from that fire has
Speaker 1: been traveling through the universe and is just reaching us. Now,
Speaker 1: that's awesome, And I think the really mind blowing thing
Speaker 1: about that is that it comes from every direction. Like,
Speaker 1: as you're saying, you look out into the universe, you
Speaker 1: look at something that's the age of the universe away.
Speaker 1: You're seeing something that was really far away a long
Speaker 1: time ago. Now you look at the opposite direction, you're
Speaker 1: seeing something which was the other side of the universe
Speaker 1: when it was born. Hold On, I have so many
Speaker 1: questions for you. But before we keep going, let's take
Speaker 1: a short break. Let me change back off a second.
Speaker 1: I'm still a little bit confused. Um, So what you're
Speaker 1: saying is that you know, there's there are the galaxies
Speaker 1: that are the furthest that we can see. Yeah, but
Speaker 1: you're saying, like if we point our telescope just to
Speaker 1: the right of that oldest galaxy into literally like black nothingness.
Speaker 1: Anything we get when we point our telescopes to that
Speaker 1: black spot sort of must be as old as the universe.
Speaker 1: Like if we see it in an optical telescope, then
Speaker 1: we're probably saying something else. But just to the right
Speaker 1: of that old old galaxy, there's radiation coming from that
Speaker 1: point that has not hit anything until it's hit us.
Speaker 1: Then that's been traveling for like thirteen point eight ish
Speaker 1: billion years from a time when the universe was only
Speaker 1: about years old. Oh, I see, but it somehow ended
Speaker 1: up there and then it had to make its way
Speaker 1: to us. Well, it was everywhere, I mean, every part
Speaker 1: of the universe put out radiation at that time. Like
Speaker 1: the universe is this like fireball kind of state, and
Speaker 1: the whole universe is cooling at the same time, right,
Speaker 1: and so you have the gas is cooling down, and
Speaker 1: there's this radiation that's traveling in every direction. That's like
Speaker 1: escaping from the time when the whole universe is on fire,
Speaker 1: and that light goes in every direction. So if we
Speaker 1: look in one direction and we're seeing the early universe,
Speaker 1: and then we look in another direction. We're not seeing
Speaker 1: the same part of the early universe, right, right, right,
Speaker 1: We're seeing different parts of the early universe. But you
Speaker 1: have to think of time in a kind of geometric
Speaker 1: way for this to make sense, right, So I kind
Speaker 1: of like to think of like we have these like
Speaker 1: spherical shells of time around us. Okay, so yeah, yeah,
Speaker 1: imagine you have your your head is inside this sphere
Speaker 1: one ft in radius that's a nanosecond in the past,
Speaker 1: and then you know, you build another sphere that's two
Speaker 1: nano seconds in the past, and then you build a
Speaker 1: sphere that's you know, a light year in radius, and
Speaker 1: then you're that's your one one year ago sphere, and
Speaker 1: then you just kind of keep going. So you have
Speaker 1: these sort of nested spheres of deeper and deeper time.
Speaker 1: And at the very end of that, the largest sphere
Speaker 1: is the observable universe, and that sphere is this fireball universe.
Speaker 1: So you're saying the universe when it was really young
Speaker 1: looked like a fireball. Yeah, I mean every part of
Speaker 1: it was was plasma. What does that mean, like a
Speaker 1: cloud like a gas. Yeah, it was too hot for
Speaker 1: Adams to be neutral, so it was protons and electrons
Speaker 1: flying around and radiation, so it would have looked like
Speaker 1: a fire in the sense that it was just glowing
Speaker 1: hot and then over time it's cooled down. So you
Speaker 1: wouldn't want to be around in the early universe. No,
Speaker 1: it would not be safe. The dangerous baby. Yes, yes,
Speaker 1: definitely if you get into like even earlier times, like
Speaker 1: the first few seconds and before, like it's like nuclear
Speaker 1: reactions in every point of space at all times. You
Speaker 1: know it's bad. It gets real bad you go earlier
Speaker 1: and there there in the universe. So it was such
Speaker 1: a hot mass of soup soupy mess that nothing could
Speaker 1: even form. And so that you're saying that fireball um expanded,
Speaker 1: that's the big bang, and it dissipated, but we're still
Speaker 1: sort of seeing kind of the afterglow of it. Yeah,
Speaker 1: And I don't want to I don't want to imply
Speaker 1: that the universe was like an expanding sphere, because it
Speaker 1: might just be infinite in every direction and not really
Speaker 1: have like a shape to it per se. It might
Speaker 1: be infinitely huge. We don't know. We don't know for sure,
Speaker 1: but but the idea I guess is that you know,
Speaker 1: when people go outside and night or even during the day,
Speaker 1: they're getting an image of the baby Universe when they
Speaker 1: look up. That kind of the idea if they could
Speaker 1: see in the microwave spectrum, then yeah, they'd get a
Speaker 1: little bit of that sort of glow from the early universe.
Speaker 1: It turns out if you if you have one of
Speaker 1: those old TVs that picks up broadcast, you know, not
Speaker 1: not the digital kind. Little bit of the static on
Speaker 1: those things is is the afterglow of the Big Bang,
Speaker 1: the cosmic microwave background. So you can actually see the
Speaker 1: Big Bang in the snow on old televisions. But but
Speaker 1: the picture of the baby Universe is not like snow.
Speaker 1: It's not um like a glow or noise. It actually
Speaker 1: has like a it's a picture right like it. It's
Speaker 1: got a specific texture on it, right yeah. Yeah, So
Speaker 1: we can map it out. If we take these microwave
Speaker 1: telescopes and look at every point on the sky and
Speaker 1: map out the microwave radiation, then we can see where
Speaker 1: some points were a little bit hotter than others, and
Speaker 1: you can see kind of these patterns of little splotches
Speaker 1: for hotter and colder spots on the you know, background
Speaker 1: light and the background light. You know, it looks like
Speaker 1: a sphere around us, just like if you were in
Speaker 1: a planetarium, you'd see, you know, um, the stars and
Speaker 1: a sphere around you. And we can look at those
Speaker 1: patterns and figure out where, like there was a little
Speaker 1: bit more matter in a spot, a little bit less
Speaker 1: matter in that spot. And we can see traces of
Speaker 1: like sound waves traveling through the early sort of fireball universe,
Speaker 1: because it turns out when the universe is that dense,
Speaker 1: sound can travel through space. Yeah. Yeah, so the early
Speaker 1: universe was like ringing with sound waves and you can
Speaker 1: see those in the picture. Yeah, you can see, um,
Speaker 1: you can see like patterns associated with like sound waves
Speaker 1: traveling through the sort of plasma. So it wasn't just
Speaker 1: a hot mess. It was a hot, noisy mess. Yeah.
Speaker 1: It sounds a lot like my house on a Saturday afternoon.
Speaker 1: Yeah yeah, kind of like real babies, Yeah, exactly, kind
Speaker 1: of like a baby hordhead. There you go. So, um,
Speaker 1: are you're talking about this very early universe and things
Speaker 1: we can learn about how what it meant? And so
Speaker 1: what might you learn about the early universe, Like what
Speaker 1: kind of result could you get about the early universe
Speaker 1: that would surprise you or make you feel differently about
Speaker 1: like your life and our rule here in the whole context.
Speaker 1: What kind of is could you could you learn that
Speaker 1: would change your feeling about, you know, the human experience,
Speaker 1: how our universe came to be and why it is
Speaker 1: the way it is. That would be really exciting to
Speaker 1: find out. There could be other universes that may have
Speaker 1: like collided with our universe at early times, and there
Speaker 1: are ways to look for evidence of that with the
Speaker 1: couse of microwave background, and if that happened, that would
Speaker 1: be really interesting to see. And one of the possibilities
Speaker 1: for that is that the Big Bang happened because two
Speaker 1: universes kind of collided in the past and bounced off
Speaker 1: each other, and so there could be like this parallel
Speaker 1: universe out there that we might be doomed to collide
Speaker 1: with again twins, So that would be really interesting as
Speaker 1: well to know that, like there's more spatial dimensions that
Speaker 1: we can see, so you know, the universe is kind
Speaker 1: of bigger in some direction that we don't understand, So
Speaker 1: that would be really interesting. That's amazing. Would it shock
Speaker 1: you if fourteen billion years from now people could still
Speaker 1: see your baby picture I was such an ugly baby.
Speaker 1: The analogy really works because you can look back at kids,
Speaker 1: for example, when there were two or three, and you
Speaker 1: can see in them the seeds of their current personality.
Speaker 1: You can see, oh, it was a fighter, it was
Speaker 1: a screamer, a curious baby. So I think there are
Speaker 1: truths about us that are hidden in our baby pictures,
Speaker 1: the same way our truths about the universe that are
Speaker 1: secreted away in the in the cosmic bac away background. Well,
Speaker 1: thank you so much, Katie for joining us. It's good
Speaker 1: to chat about the the universe. I'm always happy to
Speaker 1: do that. Yeah, you're welcome any back, anytime, and people
Speaker 1: can find you on Twitter, right, Katie, your your handle
Speaker 1: is at a stro Katie. One word right A S
Speaker 1: T R O K A T I E. Great, Yes,
Speaker 1: that's right. Well, thank you so much for joining us, Katie.
Speaker 1: I hear you're working on a really great project these days.
Speaker 1: A new book. Yeah, I'm working on my first book.
Speaker 1: It's for general audiences, so um, you know, not not technical,
Speaker 1: but the topic is the end of the universe, So
Speaker 1: where it's all going to go, how it's all gonna end, um,
Speaker 1: what that's going to look like. What it means for
Speaker 1: the universe to have an end um It's it's should
Speaker 1: be really fun. It's called the End of Everything, and
Speaker 1: it'll be out in hopefully before the end of the universe. Yeah,
Speaker 1: it would be really inconvenient if the universe ended before
Speaker 1: the book came out. So I'm crossing my fingers and
Speaker 1: hopefully will have a happy ending or is it a
Speaker 1: spoiler alert? There aren't very many pleasant ways to destroy
Speaker 1: the entire cosmos. This is not a Disney book or hey,
Speaker 1: unfortunately great, So I hope everyone checks it out and
Speaker 1: keeps an eye for it. Thank you, Katie. Thanks, So
Speaker 1: that was really fascinating. Katie told us a lot about
Speaker 1: how we can see the history of the universe from
Speaker 1: these really really old photons that are come from deep
Speaker 1: in space and deep back in time, all the way
Speaker 1: back to four hundred thousand years after the Big Bang. Yeah,
Speaker 1: when the universe became transparent. That's an interesting constant, right,
Speaker 1: Like we think of space is black and full of
Speaker 1: stuff in it, but relatively speaking, it's kind of transparent, right,
Speaker 1: it's empty, Yeah, which is fantastic. Right. It's good luck
Speaker 1: because if the universe was not transparent, we couldn't have
Speaker 1: learned all these amazing things we learned about the universe, right,
Speaker 1: And you might think, well, of course space is transparent,
Speaker 1: but that's the thing, it wasn't always right. Around four
Speaker 1: hundred thousand years after the Big Bang is the first
Speaker 1: time that it cooled down enough that the hot plasma
Speaker 1: Kittie was talking about moved from being ions into being
Speaker 1: neutral atoms so that photons could fly through them unimpeded. Right,
Speaker 1: So it makes me wonder, what was it? How could
Speaker 1: we ever see before that? Can we see before four
Speaker 1: hundred thousand years after the Big Bang? We can, but
Speaker 1: we can't use photons. You know. It's like staring at
Speaker 1: the Sun. Right, you can see the surface of the
Speaker 1: Sun because it's shooting our photons, But you can't see
Speaker 1: photons from the inside of the Sun because those get absorbed.
Speaker 1: And so looking at the earlier history of the universe
Speaker 1: requires somehow looking inside this big ball of plasma, and
Speaker 1: we can't do that with photons, but looking sort of
Speaker 1: in time, right, we want to pierce into it in time,
Speaker 1: that's right, And so we can't see directly. One thing
Speaker 1: we can do is that we can do experiments to
Speaker 1: recreate it. You know, we can say, well, what was
Speaker 1: it like when there was so much energy focused in
Speaker 1: one place? You mean, we can make babies in a
Speaker 1: test tube. I'm not proposing that you and I make
Speaker 1: babies in a test before, as much as that would
Speaker 1: be on the frontiers of science. And also I think
Speaker 1: it's sort of inappropriate to raise that like on air
Speaker 1: in the podcast. I mean that should be a private conversation.
Speaker 1: You're like buying me a glass of wine. At least
Speaker 1: for as Joe, I'm not that easy. Um, we can
Speaker 1: recreate the conditions of the Big Bang sort of, um,
Speaker 1: just by smashing particles together, so you know, the large
Speaker 1: Hadron collider, we smash protons together. Sometimes we even smash
Speaker 1: heavier stuff together like lead or gold nuclei and try
Speaker 1: to recreate the big hot mess that was that ball
Speaker 1: of plasma, just to see what was it like and
Speaker 1: what's the physics of it and what happens. So what
Speaker 1: do you mean, recreate the conditions like the temperature or
Speaker 1: just like the crazy the pure energy nous of it. Yeah,
Speaker 1: the density of energy, right, that's essentially what temperature is
Speaker 1: in my in my understanding. You know, we're just trying
Speaker 1: to create a lot of energy into in one place,
Speaker 1: so that quirks, for example, which usually are bound tightly together,
Speaker 1: can feel free because there's so much energy around that.
Speaker 1: Everybody has so much energy, they don't they don't get
Speaker 1: tied down. You're like, be free, quargs, be free, take
Speaker 1: off your foes. It's the Cork Liberation Front is whatever.
Speaker 1: The Q left is sort of a militant group there. Um. Yeah,
Speaker 1: so you can sort of think of the LHC is
Speaker 1: like a big bang machine. You know, every time we
Speaker 1: collid were like recreating these collisions and so we can
Speaker 1: study that experiment. Makes me a little nervous that, Daniel,
Speaker 1: just like, what's what's the big deal? Because me like
Speaker 1: a big bang machine. First of all, it sounds kind
Speaker 1: of it sounds a little inappropriate. But like you made
Speaker 1: a machine that makes the universes. That's a that's a
Speaker 1: little worrying, isn't it. Well, it only makes forty million
Speaker 1: universes a second, what what could go wrong? No, seriously,
Speaker 1: people don't worry. We're not We're not creating universes at daily. See,
Speaker 1: we're creating the We're recreating the conditions of the early
Speaker 1: universe by making something that's as hot and dense in
Speaker 1: a very small space, and we're all wearing life jackets
Speaker 1: and hard hats and nobody should be concerned and diversion. Yeah,
Speaker 1: and the point is that what we're just trying to
Speaker 1: study it, and because we have these theoretical models that say,
Speaker 1: we think we know what happened before four thousand years
Speaker 1: after the Big Bang, that's the last thing we can
Speaker 1: directly see. We think we know what happened before that,
Speaker 1: so let's test it and check and try to recreate
Speaker 1: those So I see, like you have theories about what
Speaker 1: happened before four hundred thousand years into the Big Bang,
Speaker 1: and so you're trying to do small experiments that will
Speaker 1: sort of confirm parts of that theory. So that didn't
Speaker 1: you feel confident about using a theory to peer into
Speaker 1: the Big Bang? Yeah, exactly. So it's extrapolating into what
Speaker 1: we can't see, and then we're trying to test it
Speaker 1: in the lab and said, like, let's see if our
Speaker 1: theory works in similar conditions. So it's kind of like
Speaker 1: a it's like math vision, you know, like we can't
Speaker 1: technically see inside the sun, but we can see an
Speaker 1: inside using math only put on my math goggles and
Speaker 1: now I can see anything. Well, I guess, I mean
Speaker 1: you could call a that applied math or math vision.
Speaker 1: But yeah, I think we should rename all the applied
Speaker 1: math departments around the country as math vision departments. Be
Speaker 1: a math visionary. But the speaking of vision, there is
Speaker 1: another way now to see into that plasma, to look inside,
Speaker 1: and that's because we have a new way to look
Speaker 1: out into the universe, and that's with gravitational waves, which
Speaker 1: are only recently discovered. We can listen not to see.
Speaker 1: Oh my god, I hate that analogy. We're not listening.
Speaker 1: Gravitation waves don't make a sound, you know, They're just
Speaker 1: waves like everything else. So it's you mean, like there's
Speaker 1: stuff happening, but underneath that, like a rumble, you can
Speaker 1: see sort of these waves coming out. Right. Well, what
Speaker 1: I mean is that the hot plasma is is opaque
Speaker 1: to photons, right, but it's not opaque to other things, right,
Speaker 1: It's transparent to other things. It's transparent, for example, to
Speaker 1: gravitational waves. So the current theory of what happened just
Speaker 1: after the Big Bang, like ten to the minus thirty
Speaker 1: five seconds after the universe was born, is that there
Speaker 1: was a huge shock wave in space. Gravitational waves were
Speaker 1: made just at the very very beginning of the universe,
Speaker 1: and gravitational waves can pierce plasma, they can go through
Speaker 1: anything because they are the shaking of space itself, right,
Speaker 1: so nothing can block them. So those can pass through
Speaker 1: that plasma. When those waves have dispersed out into the
Speaker 1: infinity by now, when we have lost them by now, well,
Speaker 1: it's just the same as with the photons from the
Speaker 1: cosmic microwave background. If the Big Bang happened everywhere all
Speaker 1: the time, then those waves were created everywhere and went
Speaker 1: in every direction. If we want to see them now,
Speaker 1: we just listen, you know, in some direction a long
Speaker 1: long time ago, and they should be arriving now. Gravitation
Speaker 1: always made super far away fourteen billion years ago, should
Speaker 1: just be arriving on Earth now. And you're right, it's
Speaker 1: very hard to see. It's like the whole room is reverberating, right,
Speaker 1: kind of like, yeah, exactly, reverberberating. And the cool thing
Speaker 1: is maybe you've heard this story, but you know, there's
Speaker 1: a collaboration that had a telescope listening for these and
Speaker 1: they thought they heard them. This is the bicep collaboration,
Speaker 1: and they claimed the discovery and then it turned out
Speaker 1: that it was just dust and they were actually totally
Speaker 1: wrong and they had to walk back their discovery, which
Speaker 1: is kind of embarrassing. Yeah, but you know, it happens
Speaker 1: in science, right, Yeah, it totally happens, you know. Yeah,
Speaker 1: it's they didn't do anything wrong. They just you know,
Speaker 1: they claimed they discovered it. They made their best statement,
Speaker 1: and then they learned more and they said oops. And
Speaker 1: that's fine. That's the process of science. Um. But there
Speaker 1: are ways to see those. We just haven't heard those
Speaker 1: vitational waves yet, but people are working on it. One
Speaker 1: day we'll find them. So those might tell us what
Speaker 1: happened inside of the the really really baby universe, right yeah, exactly,
Speaker 1: you know, the fetal universe or something, you know, and
Speaker 1: just after it was born. And that would be fascinating
Speaker 1: because we could learn a lot. First of all, if
Speaker 1: we see them, that confirms that these gravitational waves were
Speaker 1: made and that we think inflation probably happened, and that
Speaker 1: would be incredible, right that would that would go from
Speaker 1: math vision to like you know, I don't know, um,
Speaker 1: math discovernment. That's the worst probably anyway, Yes, so we
Speaker 1: could see very very early on and that would be cool. Um,
Speaker 1: But we haven't heard those yet. People are working on it.
Speaker 1: So how far how far into the Big bank could
Speaker 1: we listen with these gravitational waves? Yeah, tend the minus
Speaker 1: thirty five seconds after the Big Bang? Why not just
Speaker 1: call that zero like it's so much happy because zero
Speaker 1: and math. Put on your math goggles. There's a difference
Speaker 1: between zero and tend of the minus thirty five. Although
Speaker 1: I'll admit I don't even know what prefix goes before
Speaker 1: that could have second or a yapto second or something.
Speaker 1: What do you think it is? Um? I think it's
Speaker 1: a sound second. I think it's a Jorge second channel
Speaker 1: a second or something. It's a baby second because it's
Speaker 1: because it's so tiny. No. Um. So that's a really
Speaker 1: exciting way to probe the very very very early universe.
Speaker 1: But wait, wait, where does that number come from? Tend
Speaker 1: to the minus thirty five? That seems very like definitive. Oh,
Speaker 1: there's a lot of uncertainty there, but it comes from
Speaker 1: calculations about how inflation happened. You know. Inflation is the
Speaker 1: process of the universe stretching really really fast just after
Speaker 1: it was born. You go from a tiny microscopic dot
Speaker 1: um or every tiny microscopic dot was then just stretched
Speaker 1: out to a really big universe. The universe expanded by
Speaker 1: a huge amount in a really tiny amount of time.
Speaker 1: We should do a whole podcast on what is inflation? Sometimes, Um,
Speaker 1: that's when inflation stopped. Yeah, but that's just it's an estimate,
Speaker 1: and there are different theories of inflation. And you know,
Speaker 1: it could be tend in the minus thirty six seconds
Speaker 1: or tenda minus thirty two seconds. And but of course,
Speaker 1: as you say, why isn't it ji zero? And we
Speaker 1: love to see zero, and we'd love to see the
Speaker 1: first moment when time was created. Did something happen at
Speaker 1: ten to the minus thirty five that's when inflation stopped? Yeah? Yeah, So,
Speaker 1: very very briefly, the history of the universe is the
Speaker 1: universe is created somehow mysteriously totally unknown process, and then
Speaker 1: it's stretched really really dramatically, really really quickly for about
Speaker 1: ten of the minus thirty five seconds, right, and then
Speaker 1: it's been expanding ever since. And then about five billion
Speaker 1: years ago, I started stretching again, and that's what we
Speaker 1: call dark energy. Oh I see, so you couldn't these
Speaker 1: waves gravitational waves wouldn't tell you what happened when it
Speaker 1: was stretching or before it stretched. Yeah, there's sort of
Speaker 1: the results of the stretch. You know. It's like, oh,
Speaker 1: if you jump onto a trampoline, you know, these are
Speaker 1: the waves that moved through the trampoline. Inflation caused these waves.
Speaker 1: It's like the bang of the Big Bang. It's the
Speaker 1: bang just after the Big Bang, and you lived just
Speaker 1: down the street from the Big Bang, and this is
Speaker 1: what you hear, all right, So then, um, but then
Speaker 1: who knows, how would we ever see what happened before?
Speaker 1: I know, I'd love to see at zero, right or
Speaker 1: even negative, like what happened before? What was there before
Speaker 1: and what made the universe start? And that's it's hard
Speaker 1: to imagine how we could ever see that, even see
Speaker 1: before tend of the minus thirty five, to see what
Speaker 1: was happening at zero and fierce that veil and go
Speaker 1: through it and see what happened before. That's just the
Speaker 1: realm of science fiction. It may literally be impossible. You know,
Speaker 1: maybe that no information from before that was even preserved.
Speaker 1: It's just like destroyed um in the Big Bang. We
Speaker 1: don't even know. You don't think even math vision could
Speaker 1: get us through. I mean, like, you know, like, could
Speaker 1: we form a theory that just put on two math
Speaker 1: goggles and right, what's the big deal? Uh? No, we
Speaker 1: certainly could. And you know, this is an interesting question
Speaker 1: of like can you even study that. Is this philosophy
Speaker 1: or is this science? Can you talk seriously about what
Speaker 1: happened before the Big Bang or what caused the Big Bang?
Speaker 1: And people like to talk about crazy ideas like the
Speaker 1: Big Bang was the result of the collisions of two
Speaker 1: other universes and higher dimensions, and I mean, I know
Speaker 1: it sounds like I just made up those words. I
Speaker 1: don't mean anything, But that's a real theory. You mean, like,
Speaker 1: could we talk about anything before there was anything? That's right? Yeah,
Speaker 1: when there was nothing? Can we talk about something right?
Speaker 1: That sounds like that bid in spaceballs or something? But
Speaker 1: but yeah, and it's it's a reasonable question. And some
Speaker 1: people say you can't it's just philosophy because we can
Speaker 1: never test it. We can never know what happened because
Speaker 1: we can never get any data that confirmed or denied
Speaker 1: any of those theories. But other people say, you know,
Speaker 1: you could. Sean Carroll, for example, he argues that you
Speaker 1: can talk about what happened at a time or a
Speaker 1: place you can never visit, because you can build theories
Speaker 1: that extrapolate, as you were saying, using math vision into
Speaker 1: that time, and you can confirm or deny those theories
Speaker 1: in time and places that you can test, and you
Speaker 1: can think about whether that extrapolation is valid and test
Speaker 1: those in other ways. So it's indirect, but you know,
Speaker 1: there are ways to talk about what might have happened.
Speaker 1: Then it's just it would be hard to kind of
Speaker 1: put your finger on it and really kind of see it,
Speaker 1: especially because a time equal zero, your finger doesn't exist.
Speaker 1: To put it anywhere does it be really hot? So
Speaker 1: don't put your finger right now. People don't put your
Speaker 1: finger on a big bang. Yes, So, you know, if
Speaker 1: you look deep into the history of the universe, you
Speaker 1: learned about how the Earth was made. You learned about
Speaker 1: how the Solar system was formed, You learned about how
Speaker 1: galaxies came together, You learned about how the universe is expanding.
Speaker 1: You learned about the first stars. You go all the
Speaker 1: way back to the very initial moments when the universe
Speaker 1: became transparent, and that's you know, what we think about
Speaker 1: when we think about the universe and you learn all
Speaker 1: this rich history and it's told us so much about
Speaker 1: who we are and uh and how everything works and
Speaker 1: you know what's gonna happen. So it's it's pretty fascinating.
Speaker 1: I love looking at the universe's baby picture. Yeah. Now,
Speaker 1: there's a certain definitely comfort to know in your origins, right,
Speaker 1: Like if you didn't know if you were born or
Speaker 1: where you came from, it kind of tends to unseckle you, right, Like,
Speaker 1: what is my place in the universe? It all could
Speaker 1: just be a manufactured, you know, illusion from the creators
Speaker 1: of the simulation that we're living in, right, So it
Speaker 1: could all just be a lie. Yeah, but we're what
Speaker 1: what were they like as a baby? Though? That's right,
Speaker 1: it's a recursive question. But I totally agree with you.
Speaker 1: It tells you something about who you are, and you
Speaker 1: like to know that thing those things because it tells
Speaker 1: you how to live your life. Right. If you know
Speaker 1: where you came from, you have an idea of where
Speaker 1: you're going and how to get there, and what's important,
Speaker 1: what your place in the universe is, you know? Yeah,
Speaker 1: and your place turns out is very small, almost nowhere,
Speaker 1: pretty cold, cold, it's pretty cold. Yeah, but you should
Speaker 1: still go on and live your life and be nice
Speaker 1: to people. Yeah. If you still have a question after
Speaker 1: listening to all these explanations, please drop us a line.
Speaker 1: We'd love to hear from you. You can find us
Speaker 1: at Facebook, Twitter, and Instagram at Daniel and Jorge That's
Speaker 1: one Word, or email us at Feedback at Daniel and
Speaker 1: Jorge dot com.