Special 200th episode!

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Speaker 1: Yeah, orgey, do you know what today is? Is it a special day today? Oh my god, I can't believe your forgot? Is it your birthday? Try again? Is it the anniversary of the Higgs Boson closer? It's actually our anniversary. Today is our two hundredth episode of Daniel and Jorge Explain the Universe. Two hundred episodes. Oh my gosh, it's a lot of physics and a lot of banana jots. It's a whole universe of banana physics. Hi am orhand my cartoonists and the creator of PhD comment. Hi. I'm Daniel. I'm a particle physicist, and I know at least two hundred things about physics, and I know at least two hundred bad jokes about physics. I've made ten to the two hundred bad jokes about physics, but our editor has removed most. And Welcome to our podcast, Daniel and Jorge Explained the Universe, a production of I Heart Radio, a project we started to explain to you all the amazing and crazy things out there in the universe, all the things we do know, the facts we've learned about the universe, the secret truth that we've revealed, and also the incredible questions, the things that science still has to figure out, the questions that scientists are asking, and the questions that you are asking, the deep mysteries of the universe around us. Because it turns out that there are more than two hundred questions you can ask about the universe and more than two hundred amazing facts to learn and to discover about how this crazy cosmos works. At least that's what we've discovered in doing this podcast. We had no idea how long we could keep going on. Yeah, today is a very special episode. It's our two hundred episode. What does that make it anial? Is it like a birthday, a broadcast day at pot day? I don't know, but you know, if you look up anniversaries, like you know, the fifth anniversaries paper, and the tenth anniversary is silver or whatever, the fiftieth anniversary is diamond. There is no culturally acceptable gift for two hundredth anniversary because he's ever lasted that long. I think they give you a Nobel price if you somehow managed to celebrate two hundredth anniversary, Maybe you should be the fossil anniversary something, because you've become fossilized. But congratulations Daniel, two hundred episodes. Did you ever think we would get to two hundred episodes? No? I thought you get sick of talking to me about physics after about ten or twenty. No, congratulations to you. Also, it's been a really fun ride. And thank you to all of our listeners who have listened to us talking about science and joking about bananas and shared your goofy curiosity with us. That's really what's powered us forward. So thanks for listening, and thanks for all the feedback and support. Well, I have definitely not gotten tired of listening to amazing physics and to listen to you explain rated. Um, I feel like I could go another two hundred episodes. Let's do it. Well. In honor of our two hundredth episode, I put out a tweet asking folks what we should do to celebrate our two hundredth episode, and as usual, I put out some silly suggestions and we did a little Twitter poll. Yeah, and so Daniel asked what should we do for a two hundred episode? And the options were one, eat two hundred bananas, to answer two hundred questions, three to two hundred different accents, and number four just shut up. And explain. That's right, and clearly I was going to do the explaining, but I was hoping that you would do the bananas in the accents seems a little lopsided. Daniel, Well, you're the creative one, right. How can I eat bananas and accents at the same time? Those count as different accents, you know, like Scottish or Scottish with the banana in your mouth sound very different. It was a close pole. It was a close poll, yes, exactly what it was. It dramatic like as you saw the numbers come in. Um, well, bananas was racing to the lead in the beginning, but eventually people voted for Answer two hundred questions got about thirty five Eat two hundred bananas in second place, and you know in last place was due two hundred accidents, which I was sort of hoping for. I think we have to trust the wisdom of the crowd here and not offend two hundred countries we can. There aren't two hundred countries to offend, so that would be pretty impressive if we could offend non existing countries. Yeah. So the top option was Answer two hundred questions, which when Daniel told me, I said it was a little impractical for a fifty minute podcast, that's right. They have to be like true or false questions, or you know, yes or no, or something which wouldn't be too satisfied, right. I started to think, if we take five minutes to answer each question, that's a thousand minute episode. That's basically the next two hundred episodes. Basically, we'd be done. We could celebrate our four hundred anniversary next week. Then, well, this podcast is really accelerating the logarithmic scales. We'll be doing our four thousand one in a month, that's right. And I started looking through the list of questions we've answered over email, because I answered hundreds of questions a week from listeners, and there's a lot of common things in there. But then or I had a better idea something else we could do to celebrate our two hundredth episode. Yeah, so it's be on the podcast. We'll be asking two hundred questions, but not two hundred number of questions, but a couple of questions about the number two hundred. That's right, because while the number ten and the number one hundred, and therefore the number two hundred are really just artifacts of the number of fingers we have in the way the human mind works. It's also an interesting way to ask questions about the universe, to think about like how far away are things or what happened in certain moments of time in the universe. It gives you like a fixed window to examine the universe. We'll be asking coincidentally to two hundred questions here in the podcast, and the first question has to do with what happened at the beginning of the universe. So the question is what happened in the first two hundred micro seconds of the universe. And then later on we'll tackle the another question about with the number two hundred, which is what can we find within two hundred light years of Earth? So a little bit of time and a little bit of space, a little bit of space time, Daniel, that's right. What can you find within two hundred light years of Earth? Makes me think like, are you looking for your keys? Are they somewhere out there in space? I do lose my keys a lot, even even in a pandemic where you don't go anywhere. Somehow I managed to lose my keys like every day. Well, we'll see if we can find them, all right, we'll tackle this first question first, which is what happened in the first two hundred micro seconds of the universe. Now, two hundred microseconds, that's like, boy, that's like point to milliseconds. It's not a lot of time. But it turns out a whole lot of stuff happened in the first two hundred microseconds to the universe. Basically everything's been boring ever since. Well, two d micro seconds. That's that's shorter than a blink, right, Like a blink is maybe a couple of microseconds, a couple of milliseconds. It's a very small amount of time. Absolutely, Yeah, So a lot happened in those first microseconds. A lot happened. And one of the most interesting questions really is how you even define like moment zero. If you're gonna say, let's take a window of time from the very beginning of the universe to two d microseconds afterwards, it's interesting to think about, like how the universe expands and cools, and we'll get into all of that. But then you have to wonder, like where does T equal zero? How do you define that moment? Do we even know that there was a T equal zero? So already like anchoring the left side, the early side of that window is very, very difficult. It makes me think, like was there a T minus one or like a countdown to the universe. Nobody really knows, And the problem is that we don't think about the history of the universe in that sort of forward way because we don't really have anything to build on. We don't know what was in the beginning or when the beginning was. Usually we think about it sort of in the reverse. We look at the universe now, and we look backwards in time as we look further further out into space, right, because remember the further out in space, you look older the universe is. So we can see how the universe looked a hundred years ago, a thousand years ago, a million years ago, a billion years ago, etcetera. And we can project backwards in time. So we tend to think of the history of the universe sort of from now and running the clock backwards, and we can do it pretty well, you know, back about thirteen billion years or so, But then it gets pretty murky and we have trouble extrapolating back. We don't know if there was a T equal zero, if there was like a T equals question mark, or who knows what was happening at the very beginning. That's interesting. Now, why does the picture he get fuzzy beyond if you rewind back to more than a few hundred thousand years from what what might be the beginning of time? Like what what? What actually marks up? Well, the reason is that things change, Things get really hot and dense. Right, the overall history of the universe is cooling and expanding, and so if you run that backwards from now we have a cold, large universe. You run that backwards, things get hotter and denser. And of course you could just do that naively, like assume that the laws of physics we have learned today from our cold universe still work back then, and just run the clock backwards and you get infinite density and you call that T equal zero. You could do that, but we don't think that's right. We don't think the laws we have work anymore as things get that hot and dense, just like you know, the physics of gases is different from the physics of liquids and the physics of solids, and so things change as you get hotter and denser, and then it becomes difficult to extrapolate because we're reaching into regions that we can't see anymore and we have no experience of because there's a moment in the early universe when the universe cooled. It was a hot, dense, nastiness, will talk about it, and it cooled to a place where light could fly through. It became transparent, And that's the last moment in the early universe that we can actually see. Beyond that, we're just really sort of guessing and extrapolating and using models, but those models are very uncertain. We really don't know what we're talking about. So a lot of the details we'll talk through today in this episode are really speculative. They're like, maybe it was this, and maybe it was that, and under various assumptions which seemed reasonable but could be totally wrong. You know, maybe this happened, But it's really guesswork. Is it guesswork because we don't know, like our simulations don't aren't very definitive, or like the physics of the universe might actually change it in those kind of conditions. We don't know how the physics of the universe operates in those very hot and dense environments. You know, we've only experienced it when it's pretty cold and separated, and so we're extrapolating back. We think we have ideas or how it might work, and we can simulate various ones of them, but we can't necessarily like tell the difference between if it's like this or if it's like that, and so we just we're extrapolating into the unknown, and and that's always very dangerous and delicate. Now, even the concept of time equals zero is weird, right, because I've heard people say that, you know, like it's it's almost like asking what is more north than the north Pole? Because once you get to the north pole, there's no more north? And is it the same? Also that you know, maybe time started at T equal zero and there was no time before that. It sounds bonkers to say that, right, like there was no time before that, because it's before mean if there was no time, right, It's it's confusing. It's hard to really get these ideas into your head. But it's true that some theories of the universe say that space and time were created at some moment and things have expanded and cooled since then, and before that point, there was no time, There was no space, there was no before that point. That's really hard to grasp your mind around because your mind lives in that space in that time. It's all you've experienced, and so it's all you can really imagine how you organize your thinking. It's how we think about causality and logic, and a it happens, then be happens, then see happens. But it doesn't mean it's the only way the universe can be. And so it's extraordinarily difficult to sort of extrapolate your brain and you're thinking into something completely unfamiliar, right, And so what we do is we have these frameworks like general relativity and quantum mechanics that try to tell us about what might have happened, But those aren't very conclusive either. I guess the North Pole analogy kind of works also in that, you know, like here where we are. You know, if you have like a compass, it's pretty clear how to use it, Like, you know, it tells you north and right and south and east and west, and you can walk around pretty easy blue. But if you are like near the North Pole, it might be a little tricky to use a compass, right, Yeah, if you're at the North Pole, you'd be a little disoriented. Yeah, if you're at the north pole. There is no more north to go, right, you can't go any north eier than that. But we don't know if time works that way. It could be that there was stuff for you know, these early moments, these singularities. There was a whole other universe perhaps which came down into a big crunch or something else totally different, some sort of other weird kind of thing which gave birth two hours space and time. You know, our entire universe, Our space and time could be a bubble of that other pre universe stuff like decaying into a universe. There could be a whole spectrum of other universes also that were created in the same moment, or the could that are still being created now. There could be like you know, moments of creation happening right now, really far away in this other meta space. It sounds like bonker speculation because it is mostly because we're so clueless. You mean, like now, like as we speak, there could be some time equal zero moments right now for other universes in this universe. Yeah. One idea of how our universe got started is that there was some sort of like pre universe stuff some Inflaton fields, and that our universe is essentially some random spontaneous decay of at and that's when our universe began, and that influence on Field is just like expanding and creating and eternally inflating. But all the time it's parts of it are decaying and starting whole new universes, their universes that haven't even gotten started yet, in universes that are trillions of years old. And none of this is anything we know. It's just like it's a crazy idea, and in a thousand years people will read about these ideas the way we think about, you know, the Greek's ideas about air, water, fire, and earth. We're like, well, that's cute, you know, and it could have been true. I suppose, yeah, it's it's well meaning, carefully thought out, totally wrong, And that could be the way we describe all of our current ideas about what happened to T equal zero and whether T equal zero even makes sense. It could be like cute to future busicists, exactly lessly cute to a future five year olds. Man, five year olds, and a thousand years will laugh at our ideas that were like, oh, you're ridiculous, that's silly, oh man, well, five year olds already laugh at me, Daniel, so that that's going to be We'll pretend that's on purpose though, all right, so it seems like, okay, so we can't see that well beyond a few hundred thousand years into the universe. So really asking like what happened in the first twohundred microseconds is really speculative, then that's right. All you can do is say, like, you know, extrapolate backwards from where we are it gets hotter and denser, hotter and denser, and pretend that you know how to extrapolate back to some point like general relativity says you can extrapolate all the way back to a point of infinite density and temperature. But you know, we know that general relativity is probably wrong when it talks about singularities and stuff like that, because it ignores important things like quantum mechanics, which tells us that you can't have an infinite amount of stuff in a tiny zero volume point and know all about it. So definitely something wonky happens. But you know, you can extrapolate sort of naively and say we'll call this t equal zero and we'll move forward from there. I see, I see so we're gonna plant the flow. I can say this is tequals zero, and then we're going to see what can the universe do to get us to where we are today? Kind of yeah, exactly. All right, well let's get into that and to the question of what is within two hundred light years of Earth? But first let's take a quick break. All right, Daniel, we're celebrating our two birthday. Does that mean that I'm two years old and you're two hundred years old, or we're each a hundred years old? It means we should have retired a hundred and thirty years ago. I feel like this podcast has aged me two years. I feel like I'm two hundred light years from where I started. There, you go, all right, well, so we're talking about the first two hundred microseconds of the universe, and so we'll start with time equals zero. What what happened at times zero? Daniel? We don't know, but one idea is that there was a singularity that you know, the universe was super hot and super dense. And I think a lot of people imagine this as a single point. They hear singularity to think a single point. They think one hot, dense spot like the entire energy and all the matter of the universe was in a really tiny dot. But it's better not to think about it as one place, but more to think about it as the density. Because we don't know if the universe is finite or infinite. Possible that when the universe started it was already infinite, and that this singularity we're talking about was everywhere like multiple singularity, yes, yes, precisely, like a non singular singularity. Yes. Like the singularity refers not to how many of them there were, but the fact that the density becomes infinite singularity refers to what happens to the equations, that the equations get infinities in them, because the density becomes infinite, not the size of it. And there's a i think a very common misconception that the Big Bang or pre Big Bang starts with a dot, and a dots small than an adam becomes the entire universe. And because we don't know how big the universe is, it could have been a little blob, it could have been an infinite extent. It's better to think about it in terms of infinite density, or like an infinite number of dots, an infinite number of dots. Yeah, The thing we do know is that the universe was denser and harder back then. We don't know how much of it there was, could have been infinite, could be finite, and loop all around on itself. That's a whole other episode about the size and shape of the universe, which is fascinating. But to think through the history of the universe is mostly to think about the density changing da days that you know, there's no real reason for this to exist, just somehow the universe what we know was really dance, almost like infinitely dance. Yeah, there must have been a reason for it to exist, because it does. And we think the universe follows reasons and laws. We just don't know what they are and we can't argue for it. We don't know why there was something instead of nothing, and why there was this, and could there have been other things, and you know, just really shockingly basic questions that we have really no clue about. Okay, so we had to super dance state almost infinitely dense, maybe everywhere, maybe just one dot, and then what's next thing that happened and what happened in the first tend to the minus you know, forty three seconds, so The picture you should have in your mind is that we have space, and space is really really hot, like there's a huge amount of energy. Right. The density we're really talking about there is energy density. And if you've been following the podcast, you know that we like to think about space in terms of quantum fields. Every point in space has fields in it, the electron fields of cork fields, the photon fields, etcetera. And particles that we think about today are little blobs of excitations of those fields. Today, most of those fields are very very low energy. Most of space is empty in those fields are zero. But back then, infinite density really means all those fields are going nuts. They're going crazy, they're oscillating, they're just full of energy. And so instead of thinking about individual particles, it's like having an ocean, right, you don't think about a drop of water. When you have an ocean. You can just think about the entire crazy, turbulent blob and it's doing all sorts of stuff. So the first ten to the minus forty three seconds of the universe we called this the plant epoch. Everything was hot and dense in these fields were just going crazy. Now I have a question, though, somebody's talk about that. It's not just like stuff that was crammed in together really tightly. It's also that space itself was smaller, much smaller. So it's like it's both those things. It's like everything was crowned in together and also space was smaller. That's right. There's two kinds of expansion we're gonna talk about later. One is the expansion of stuff through space as things spread out into existing space. The other is the expansion of space that you create more space, and new space itself is created. Because remember that space is not just like a backdrop on which things happen. There's a dynamical connection between space and energy. Space curves and bends and expands in response to the mass and energy that's in it, and then it shapes the motion of that mass and energy. So space and mass and energy are two things that are very tightly coupled and respond to each other. Okay, so in the first you know point zero zero zero zero down to forty zeros one seconds, you said, that's called the planet. Yeah, and back there we had a bunch of really hot fields. And the thing to think about here is that there are no particles. What it's it's like too hot for particles like particles just kind of everything is just crazy. That's right. There are no isolated particles because everything is just too hot and too intense. It's all just energy in these fields. It's slashing around. You know, later on things will cool down enough for particles to form. But particles are like you know, when you have a few little isolated blobs of energy in the field. Here we have like an incredible turbulent ocean. So it makes no sense to think about in terms of particles. I mean, technically you could, you could say this field is ten ca jillion particles in it, but it doesn't really make any sense. It's really just energies, not discrete packets being around through space. It's just a huge blob of energy slashing around in the field. I see. There's no moment where you're like, oh, there's an electron. It's just that the whole field is just sit on fire. Yeah, precisely. You can't follow a drop of water in the ocean, right. And the other thing to think about is that the fields here behave differently, just like the way materials on Earth have phases as you cool them or or heat them up. The physics of them changes completely, right, The same thing happens for fields. They tend to act in different ways at different temperatures and different energy densities. And this is not like the laws of physics changing. It's just like how you can think about it, how you can describe it. The effective the emergent results of it are very different at different temperatures, just the same way they are for solid But can we still use the same equations we have, Like do our equations still work? We don't think they do. We think the equations that we have now only describe physics sort of at lower temperatures, that they're sort of like the falling at the effective equations for what happens when things are old. We don't think we have like the fundamental equations. Our equations should be like the low temperature limit of the true equations, which we haven't found yet. But for example, and we think that a very hot temperature is the early moments, all of the forces acted like one gravity, electromagnetism, the weak force, and the strong force. We think they're probably all just one force that acted together. What do you mean of force? Don't forces depend on particles to no? Forces are also just fields? Right, But we think that there was a single field that represents all those forces but combined into one. And we think when it was really hot and dense, that they acted together. They all had the same strength, and there were all just different components of one mega force which exists in the universe. Well, I think you just coined the term right there at the megaphorce. This is like to call it the grand unified theory. I like megaphorce better megaforce. It is, then, all right, so those are the first ten to the minus forty three second. Is then what happened? And things start to cool, things start to expand a little bit, and the first breaking happens. Here the force splits into two. You have gravity on one side, and then all the other forces electromagnetism, the weak force, and the strong force combined still into one single force, which we call electro strong. And so here the temperature has dropped enough that the force has split. It's like cracked. You know how. Sometimes when you cool something, you can freeze, or it can crack, or it can end them as some weird configuration. As the universe cooled, gravity sort of like froze and split off from the other forces. Interesting like inevitably or is it like a random you know, like an ice when you freeze eyes, you you sometimes get crystals here or crystals there. Is it random like that or is it like inevitable? Do you think that the equations were like we were always going to get gravity and these other forces we don't know. We call it spontaneous symmetry breaking because we think there's a random element in it and all the forces you'll see as we go through time, all the forces split off, and we think that those splittings are spontaneous, that they're essentially the result of one little quantum fluctuation which then gets propagated through the universe. You know, like when everybody sits down at a dinner table, do you drink from the glass to your left to your right? Well, if one person chooses left, then you know, everybody around them starts to choose left and it spreads across the whole dinner table. Right, they could have chosen to drink from the one to their right and then everyone would use that one. So one little fluctuation like that can propagate itself through the whole universe. And we don't know if gravity splitting off was inevitable or at what temperature it should have split off? We just don't know. We think gravity split off first because it's the weakest force, and so we think it would take the hottest temperature to combine all the forces. And then fourteen billion years later, everyone's like, is this my glasses? Is your glass? Did you drink from mine? Because I thought I had more wine left over? And then people are spitting up what And then it's it's like back to the big bank, all right, So things start to split off and cool down, and then we start to get more forces defined. Uh, and then what happens next? And then the next thing to split off is the strong force. So gravity split off, and then the strong force splits off. So now we have gravity, we have the strong force, and we have the electro weak force electro week being the combination of electromagnetism and the weak force. Remember still we have no particles, so these things aren't like forces that we think of today that are balancing particles around. It's just the fields now have different properties. They operate differently, they contain energy differently, they have different strengths. As the universe is coolest, so gravity split off, but it's not like bringing anything together because there is no thing. Well, gravity is doing what gravity does. It's you know, the bending of space. But you know, even talking about merging gravity with these other forces requires a conceptual leap that we haven't made yet, which is thinking about gravity as a quantum field, which we don't know how to do, especially in the early universe. So we are really out on very thin ice, or conceptually would like maybe if gravity can be unified with the other forces, then it was the first thing to split off of some mega force which might exist. And I can't emphasize enough how much respeculating cluelessly here, Okay, right, right, if gravity is a quantum field, this is kind of what we might expect. Yeah, yeah, exactly. But it's not like we have a firm prediction that we can like interrogate and explore. It's just like, hopefully somebody clever comes along and figures out how to make gravity quantum field and maybe it would work like this. All right, So now that and we split off the strong force, now we have more forces, and then something dramatic happens at around ten to the minus thirty two seconds. Right, Yeah, here's where the excitement really happens, and we don't know why, but we think at this point, for some reason, the universe started to expand extraordinarily rapidly, like space itself expanded, not just stuff flying through space slashing around, but space itself got stretched. Remember that space can expand based on the mass that's in it, Like we know the space is expanding right now. In their current universe is something called dark energy, which is creating new space, not just pulling on space, not pushing things further apart through space, but actually like adding new bits of space between galaxies. So that can definitely happen, and we know that it did happen in the very early which were created more space. The universe just started just creating at a crazy rate. Right. It's the kind of this kind of the bang in the Big Bang theory. Yeah, this is sort of the bang and the Big Bang theory. I mean, originally people thought of the Big Bang is like a dot and things explode through space. These days, we have this period we're talking about now, which we call inflation, and then we think of the hot Big Bang is basically at the very end of inflation. But you know, the terms are a little fuzzy, but essentially here you have the biggest bang. I mean, the universe expands by a ridiculous amount. It's ten to the seventy eight ten ten to zero. So you take a piece of space that's like a nanometer across, very very quickly, in like ten to the minus thirty two seconds, you expanded to a hundred trillion kilometers. Crazy. So in ten to the minus thirty two point zero zero zeros one seconds, the universe for some reason just was like come out of here. Yeah, exactly, And and we don't know why. We we have, like you know, given fancy names to this theory to make it sound like it's a thing we know how to deal with. We call the inflation theory. We think maybe it was generated by the inflaton field, but that's really just like saying, oh, you know, the answer is a fluctuation in my cluelessness field, like I really just don't know. For this into the framework of ideas, so it sounds clever, so they're like, oh, they blew up. And it could be, you know, that it's triggered by the electroweak breaking that like maybe breaking off the strong force from the electroweak force created the infloton field or settled the infloton field into a way that made it do this crazy expansion. But this is guessing upon guess. We are very confident that inflation happened. I mean the things that it predicts are very specific and very concrete. You know, like before inflation, the universe is very hot and dense, but not totally uniform because it's quantum mechanical, and so you get subspots that have like little quantum fluctuations of a little bit more density and quantum fluctuation is a little bit less density, really really tiny variations. But then this inflation is stretching, turns those little seeds of over densities into big structures which then form the structure of the universe. And we can do all those simulations and it describes very well what we see today is thing. And I guess one question is where did all the space come from? Like when you make space, does it require energy? Yeah, we don't really know. I mean, we know that the universe is not closed, and so an energy conservation is not required by general relativity to make space, you don't need energy. Maybe, well, you know space is energy, like space has energy in it. When you create space, it has all these fields, and those fields have energy in them, and so when you create space, it's like creating energy. So it's not something that we understand. It's not something we know how to do, or that we understand the rules about. We see it happening in our current universe. We don't understand the mechanism behind it. We call it dark energy because we're clueless. We know that it happened in the very early universe. Maybe it's the same mechanism, maybe it's something totally different. We really just don't know, all right, So now we're getting almost to the two microsecond mark, So let's finish off what happens in the first two microseconds, and then we'll go on to our next question. But first let's to get quick break, all right, Daniel, we just exploded the universe. We just went through inflation. In the first tent of the minus thirty two seconds, one ter became a hundred trillion kilometers. Now things are expanding like crazy. Quantum fluctuations make a huge difference. Now what happens now we finally get particles. Things have cooled down enough that the energy that's in the field is distinct and discretized, and you can follow it around. You can say, oh, this little blob of energy in the electron field is moving through space in a coherent way. You can call this an electron and the same for the other fields. And so you start to get particles made, and you get the last moment of breaking that we're aware of the electro weak force, which at the time was just one force. You know, there wasn't like a separate photon and W n z bosons acting separately. It was a single force with four of its own bosons. This field now breaks, and it breaks into electromagnetism and the weak force. It becomes two forces. It becomes two forces that are still closely connected. I mean, they're two broken pieces of a larger force. You can sort of like fit them together roughly the way you can fit continents together, you know, like you can think of the mega continent breaks into little continents and now they're a little different, but the contours sort of match, and so you can think about their history. Right, And this is another example spontaneous symmetry. Breaking the Higgs field gives the photon no mass, and it gives the ws and z s a lot of mass, So all of a sudden, the weak force becomes really really weak. Interesting, and so then that's what kind of gives rise to the Higgs field, which is the one that gives mass to everything. Yeah, so the Higgs field, like all the other field started out really hot. It was cooling down and cooling down, and most of the other fields they like settled down to zero, but the Higgs field got stuck, got stuck at a certain point where it couldn't go any lower because it has a really weird shape to It's like you know, on the edge of a canyon wall. It's got a little like dip in it, so you can get stuck in a little like on the precipice, like a little buzz right, And it got stuck there. And because it got stuck there and not somewhere else, it gave mass to the ws and disease, but not the photon and also to the other part of it. So all the other particles their mass then gets fixed because the Higgs field got stuck at this value. And before so before that we didn't have mass, or we just didn't have like consistent mass, or you can't even talk about mass. It's harder to talk about mass before. The particles really are like separate, identifiable spots. But the mass of the particles depends on the energy of the Higgs field. So as the universe is cooling down and the Higgs field is cooling down, you can think of it as like the masses of the particles are decreasing because the Higgs field is cooling down. All right, So now all of our forces are in motion. Now they're in play, and particles now exist, which is crazy to think about that. We didn't have particles before. Yeah, and now they have mass or they interact with the Higgs field, and and so is that then? Kind of is that it like is it a straight line from there to here? Or are there there still things we don't know. There's a lot of things we don't know, but it's basically a straight line. I mean, now you have particles, and the interactions in play are the ones we're familiar with. There's electromagnetic fields, the weak force, the strong force, there's gravity. But you know, it's still pretty hard to understand, Like it's a hot, dense and nasty mess. Like it's mostly quarks and leftons, but they are too hot to form any larger particles, Like you don't have protons and neutrons and stuff like that, which are bound states books just quarks quarks and flying around annihilating each other, constantly turning into photons, turning back into particles. It's still hot and dense, and then things are cooling off, so like you know about after one micro second you get this cork glue on plasma. Things start to cool off, and then you get things like protons and neutrons and whatever. And there's a really interesting mystery there about like what happened to all the anti matter. If everything was symmetric, you would expect the fields to create like as much matter and antimatter should all annihilate into a universe filled with light. But instead there was some asymmetry there. We ended up with like a little bit more matter than antimatter. Most of it is gone, but a little bit of matter or was left, and that's what led in a straight line to where we are today. I think the lesson here is a lot happened in the first two hundred microseconds. We missed the big party. I just feel like we went through an hour of just to cover a two d microseconds. That's amazing, So a lot happened, right, and a lot could have happened. Yeah, the history of the universe has been pretty boring ever since. You know, like most of the excitement was in the first few tiny slices of time, and ever since then it's been pretty slow. But you know, think about it, like on the cosmic time scale, like trillions and quadrillions of years, it could be that, you know, intelligent species in septillion years. Think about the first few billion years of the universe as like, you know, the first moments, because you know, it could be that the universe is very different in a trillion years, that it's all just black holes separated by vast distances or something else forms. You know, there's so many fascinating emergent phenomena they're really hard to anticipate, and so you know, maybe this will seem exciting to people who come much much later. Yeah, I'm sure they'll say, like, you know, that day where they post the two hundred episode of Daniel and Horge Explained the Universe, that's the equal zero to us. That's when that's when the party really started. Before then, it's not even really worth there, all right, Well, I think the answer is a lot happened in the first two hundred microseconds of the universe, which is amazing. All right, we have one more question here. I think we might have to talk about it in two hundred microseconds, Daniel. But the question is pretty interesting. It's something I thought about as we try to brainstorm ideas for this episode. But the question is what can we find within two hundred light years of Earth? So I guess, first of all, how much is two hundred light years? Like a few Brazilian kilometers? Yeah, a light year is really far. So a light year is like nine point five times ten to the twelve kilometers. That's why we use light years, because the distances in the universe are so vast the kilometers become an absurd unity. So it's like two hundred million million kilometers. So if you could hop in a spaceship and go two hundred million million kilometers, where could we go visit? Yeah? So mostly the universe is empty. You know, you pick our random spot outside the Solar system and you go in a straight line, you'll see nothing for two hundred light years. Like, it's just not much there. The universe is not very dense anymore. And you know, I read these science fiction novels about people flying through space and like hitting asteroid fields and bumping into stars, and I'm like, it's just not that much stuff out there. Likely, No, It's like swimming in the ocean. How often do you really encounter a desert island? Like? Really not that often? Oh, I see, that's a good analogy. Like if you were in the middle of the ocean and you went a few hundred kilometers, you know, what are the chances that you'll hit another island? Pretty small? Yeah, pretty small. It's mostly just ocean out there. But there are things out there, and mostly within two hundred light years of Earth. There are a bunch of stars, but you know, not that close. Like the closest star really, once you leave our Solar system, the closest thing that you can find to our Solar system is a star called Proximus Centauri. It's about four point two light years away. It's done the name of an Avengers villain. I feel like I've heard that name before. Are you auditioning to be in the next Marvel movie? That's what happening here? To be the voiceover? I think Proximate can Centauri, the Marvel villain can do two hundred accents. So if you really want to audition, then we've got to hear some accents. Yeah, all right, so that's the nearest star. I guess how how many stars can we find within two hundred light years? You know, surprisingly, you can find a lot of stars. Now, on one hand, stars are not very dense. I mean, in our galactic neighborhood, there's about one star per two hundred and fifty cubic light years. But as the radius of your sphere grows, the volume of it goes up very quickly, goes up with radius cubed. So a sphere with radius two hundred light years has a lot of cubic light years, like thirty million. If you go at about two hundred light years, there's something like, you know, tens of thousands or maybe a hundred thousand stars in that volume. Really, yeah, I could visit a hundred thousand stars within two hundred light years. Yes, But you know, if you travel in a straight line two hundred years, you would probably find very small number of stars. If you completely visited a spear with radius two hundred light years, would be a hundred thousand stars there. But you know, like the list of destinations I can go. Is it's like a hundred thousand stars. Yeah, there's a lot of options. I mean, if you like decisions and you like choices, then there's a lot of options. Most of them are pretty far away. I mean, the vast majority of those hundred thousand are on a thin shell on the outside of that sphere, mostly because that's where most of the volume is. But they say that, you know, about one in five star has an Earth like planet, So we're talking about like there's twenty thousand earthlike planets I could visit. Yeah, there are definitely a lot of Earth like planets, and we think that most of those solar systems have planets like multiple planets, which is fascinating. We don't know a lot about like what those solar systems look like, and how often do you get big gas giants and rocky inner worlds, And is our solar system unusual or totally typical. Something that is unusual about our solar system that you'll discover as you look around in the solar system is how many solar systems have multiple stars. Like in the closest fifteen light years is like fifty something stars, and about half of them are single stars, just like a star with planets around it. But there's like ten of them that are binary systems, like two stars orbiting each other and then planets around the wo that's common. That's common. And even within fifteen light years there are four systems that are trinary systems that have three stars in orbit around each other. That's pretty cool. So in Star Wars when Luke is looking out at the two suns on the horizon, that's like maybe more common than you think. That's not rare. It's a lot more common than you think. And if you think about how things form, you start from a big cloud and things cold less, and so it's not necessary for its all coalesceent to one really big blob in the center of a solar system. If you have like a little bit of density here, in a little bit of density there, it can form two. Or if two stars form close enough to each other, they'll pull on each other and form one of these systems. Some listeners send me an awesome question recently. He said, are there any stars out there that have sort of two planetary disks, Like one planetary disc aligned in one way and then the second one aligned you know, at an angle to it like two hula hoops. Yeah, like two hula hoops. And I don't know if one, but there's no reason to think there couldn't be. Like if you had two solar systems that sort of merged and the stars combined in the center, or you get a binary star system in the center, they could keep each of their planetary disks and it would be at different angles, and so that could totally happen. I think that would be an awesome setting for a science fiction right, but every year you go around the Sun, you'll be like, watch out for those other this other planet is would be a drama every year. It would have to work like clockwork, but it might make for some pretty cool nighttime observations. All right, cool, So there's about a hundred thousand stars within two hundred light years. What else can we find in this bubble? Well, it's mostly it. I mean in the galaxy we have stars. Of course, we have gas clouds, which are the birthplace of stars, but there aren't any of those within two hundred light years. Like the closest one is about four hundred and something light years away. It's called Taurus, and it's where stars are being born. There are stars in there. They're like one or two million years old, But we don't have any of those big blobs inside our like two hundred light year windows, because like a cluster itself is pretty big. It's almost as big as two hundred light years. Yeah, some of these gas clouds are are hundreds of light years across. They're really vast. There's like the birthing regions of stars. But there is a cluster of stars. Like there's a big major cluster of stars. It's called the Hyades cluster, and it's about a hundred and fifty light years away. It's like six hundred something million years old, and it's just like a big blob of stars that are all together. It's probably comes from a really dense region of of gas and molecules that got formed early on, and so that's like a big blob of stars. So I see, oh wow, that must be pretty amazing to go near or to visit there. Yeah, And you know, if you're looking to visit a lot of stars and a a lot of planets at once, it's probably a good destination. On the other hand, it's a hundred and fifty light years away, so it's to take you a while to get there. Well, I think this kind of tells you how big the universe is, you know, two hundred light years, Like that's even like if we prolong human life and double it and was able to go at the speed of light, that's as far as like any one person could probably go without any kind of special awards beat or wormhole, right. Yeah, And you know the thing that's furthest away, the human device that's furthest away from the Solar system right now is voyage or one. It's traveling at sixty one thousand kilometers per hour, and if it kept going, it would take another seventy thousand years to reach the nearest star. Like, these distances are just incredible, and it's already eighteen billion kilometers away from us, but that's just like a tiny fraction of the distance to approximates centauri. I see, seventy thousand years, that's like what three thousand more episodes, Daniel, I got all those ideas. Yeah, I've sketched them out already. You would really like to work ahead. Yeah, And you know, if you think about the larger context you know of our galaxy. Our galaxy is a hundred thousand light years across. So a bubble two hundred light years is really a tiny neighborhood. You know, the Sun itself is just like is twenty something thousand light years from the center of the galaxy. So even like the most we might right now could imagine traveling to for a single human is is a drop in the bucket of the size of our galaxy. Yeah, if you were looking at a map of the galaxy, you wouldn't even notice that distance, right, Wow, alright, Well, I feel like we covered a lot in the first two seconds this podcast. And uh, we also got this kind of amazing view of how big the galaxy is and spaces and how empty it is. It's incredible how dense and hot the universe used to be and how big and cold it is today, and yet it's still filled with mystery and our whole concept of the universe, where it came from, how it began, what it looks like now, what's out there could be totally rocked by discoveries that are coming, discoveries made by scientists working today, over by somebody out there listening to this podcast right now that's thinking, Hey, maybe I could crack one of the biggest questions in the universe because you know you could. Yeah, yeah, and then we'll cover it here in our episode. That's right, And so I want to say a personal thank you to all the fans and listeners for tuning into all these episodes, for sending us supportive messages, for letting us know that you're enjoying what you're hearing, and for sharing with us all of your wonder and your curiosity, and for going on this crazy journey with us. Absolutely believe we wouldn't be doing this without you. And thanks also for letting all your friends know and all your context note because the more people that are listening, the more episodes we can make. All right, well, thanks again for helping us celebrate our two hundred episode. We hope you enjoyed that. See you next time. Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of I Heart Radio. For more podcast For my Heart Radio, visit the I Heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows