Daniel and Kelly’s Extraordinary Universe - What is making the Universe explode?

Episode Date: October 30, 2018

How we learned that something is tearing the Universe apart, and what it might mean. Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

This is an I-Heart podcast. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, everything changed. There's been a bombing at the TWA terminal. Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System

On the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend's been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now he's insisting we get to know each other, but I just want or gone. Hold up. Isn't that against school policy? That seems inappropriate.

Maybe find out how it ends by listening to the OK Storytime podcast and the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Do we really need another podcast with a condescending finance brof trying to tell us how to spend our own money? No thank you. Instead, check out Brown Ambition. Each week, I, your host, Mandy Money, gives you real talk, real advice with a heavy dose of eye. feel you, sis, like on Fridays when I take your questions for the BAQA. Whether you're trying to invest for your future, navigate a toxic workplace, I got you. Listen to Brown Ambition on the IHeart Radio app, Apple Podcast, or wherever you get your podcast. Some of the most amazing moments in science were totally unexpected.

You mean like the discovery of microwave ovens or slinkies, I heard, was awesome. discovered by accident? Yeah, but I'm thinking about the times when you go out there just to double-check something, something you thought you already understood, but you find an answer which makes no sense and forces you to change how you'd see things. Yeah, like I heard one of the most fundamental things in the universe was actually discovered this way by accident. Yeah, it's totally amazing.

It makes me wish that I'd been involved, and it makes us see the universe differently. It makes us see everything differently. Is it more impressive than a slinky in a microwave? That's pretty hard to top, but I think this one does. Hi, I'm Jorge. I'm a cartoonist. And I'm Daniel. I'm a particle physicist. And this is our podcast, Daniel and Jorge. Explain the universe.

Today on the program, what is dark energy? And why is it everywhere in filling the universe? universe? Is it powerful? Is it dangerous? Is it dark after all? Will it stain your clothes? And most important, why is it causing the universe to explode? The universe is exploding people, but don't get out of your cars. It's going to take a while. Dark energy is a mysterious topic. We went around and we asked people, what do you know about dark energy? Is it like empty space? I'm not sure. No, I have no idea about it. It's like anti-energy, this kind of thing. Is dark energy something with black holes. I don't know, but that's my speculation.

So most people really seem to have almost no idea what dark energy is, which as a physicist really surprised me because it's one of the most dramatic and amazing discoveries of the last 30 years. Yeah, but people sort of seem to have heard about it, right? It sounded really familiar, but they didn't know what it was. Yeah, some people thought it was dark matter, some people maybe thought it was something in Black Panther, like people really didn't seem to have a good grip on what dark energy is, which is amazing, not just because because it was a big discovery, but because it has huge consequences for our lives. Yeah. It's a great name. I mean, it's easy to see why people would confuse it with dark matter. They're both dark.

That's right. It is a cool name, dark energy. It sounds so mysterious. Though you're right, in the HR meeting where they decided what to call this weird physics thing, they should have considered the fact that dark matter and dark energy sound alike. I wonder if they do focus groups when they do that kind of thing. Do you think they thought, hey, all those dark matter people get a ton of grant money? If we call our stark energy, we could also get some of that money. I'm sure that was the number one concern in their minds, yeah. How will this play in my next grand proposal? Anyway, let's tell people what dark energy is and why it's so important. Yeah, well, first of all, it's a huge deal, right? Like, it's not like an obscure thing in physics.

It's like a huge part of the universe. That's right. Most of the energy in the universe is actually taken up with dark energy. Like 67%, right? That's right. fully two-thirds of all the energy in the universe is devoted to this weird, mysterious force called dark energy. And that's about all we know about it.

Like when you think of the universe and like atoms and protons and rocks, asteroids, planets, all those suns. Hamsters. And then hamsters, yeah. Hamsters, they add up to a lot, yeah. All that stuff out there in the universe, stars, that's not all there is to it, to the universe, right? a whole bunch of it is dark energy.

That's right, yeah. Most of the stuff in the universe is not the kind of stuff that we see around us. As you were saying, even stars and plants and gas and dust, that all adds up to a tiny little sliver like 5%. Turns out, and this is the kind of stuff we've only learned recently, most of the universe is weird stuff we never even thought about. We never even would have included in a pie chart of the universe 30 years ago is the biggest piece of the pie.

It's this big kind of mysterious energy. that's out there. That's right. So imagine, for example, you take like a cubic meter of space, and you ask what's in it. Well, on average, if you average over the whole universe that we can see, it has about five or six hydrogen atoms worth of energy. And most of that is not matter or stuff that you're familiar with.

Most of it is dark energy. And another big chunk of it is something called dark matter, which we can talk about it in another episode. Yeah. And dark energy is all around us, right? like right now, two-thirds of the room right now that I'm in is filled with dark energy. That's right.

Most of the energy in the universe and most of the energy everywhere. And dark energy is not something that's out there in space. You're exactly right. It's here. It's with you. It's between your toes. It's in your refrigerator. There's other dark matter between my toes.

Let's be honest. I don't think I want to know it's between the toes, whether it's a cosmic mystery of physics or not. Yeah, let's not get into my toes on this podcast. Maybe in another way. Daniel Jorge explained the universe and Jorge's toes. Yeah, that's right. That's a winner right there.

But yeah, so it's a huge deal. It's all around this, and it's causing the universe to explode. So that's kind of distressing. Yeah, not only is it turned out to be most of the universe. It has huge consequences, right? The universe is exploding in every direction. And in some ways, dark energy is causing the universe to explode. Another way to think about it is that dark energy is our description of the fact that it is

exploding. We saw the universe is exploding. We named that dark energy. It's not like there's two separate things where, oh, here's dark energy. We know that's a thing. Here's its cause. It's more like dark energy is a description of the fact that the universe is exploding and we don't really know why. It's another name for the explosion of the universe. It's a fancy title for our lack of understanding the explosion in the universe. It's like when you don't understand something, you have the PR version. We could have called it, what is going on with the universe? But dark energy sounds better. WTF energy.

WTF universe, man. Yeah, exactly. Well, let's get into that. So how did we find out about this dark energy that's all around us and it's causing the universe to explode? Well, it's one of my favorite stories in science because it's a story where the answer was a surprise. You know, scientists went into it asking one question

and learning something totally different about the universe. The question they started with was, what is the history of the universe and what is the future of the universe. Like what's going to happen eventually? Yeah, exactly. Like, is this whole universe going to keep going forever? Is it going to compress into a little dot?

Do I have time to write that novel I've always been wanting to write? You definitely have time to write that novel. No worries about that. I have no excuse. Is it another young adult novel? Because I have enough of those already. It's called Dark Youth.

Dark Youth. So you've got vampires, you've got werewolves. You've got werewolves. Yeah, that's the next formula. You know, have dark energy beings. Yeah. And so when physicists, when physicists want to predict the future, what they typically do is look into the past. And try to understand what's happened so far and then extrapolate.

So to figure out what the future of the universe was, they first looked into the past and said, what's been going on so far. And let's see what direction things are going in. Right. Like, how am I doing financially? Do I have more money now than I used to have money? money before, and that will sort of tell me what I might expect in the future if I don't make ill-advised decisions.

That's right, yeah. If your net worth has been rising, then you expect it to keep going. If your bank account is dropping every single month, then you can expect some sort of cataclysmic event in your near future. Then I need to record more podcast to make more money. That's right. That's right. And so in the physics world,

we went back to the very beginning of the universe and said, okay, the universe started with a big bang, right? And things blew up from there. And the question people had in their minds was, you know, after the Big Bang, things flying out from that huge explosion. The question was, is there enough stuff in the universe for things to slow down, for the gravity from that stuff, to slow things down, stop them, and then make them fall back in?

So that was one possibility people were considering. Right. The universe would stop, the expansion would stop and then come back into a big crunch. So, like, stuff that flew out from the Big Bang. And now the question is, like, are they going to keep flying off or maybe is there enough gravity pulling all the stuff together that it's going to like slow down and then pull back in just kind of like how our solar system formed? Yeah, exactly. Most of the stuff that we know around us in the universe was formed by gravity, right? Gravity gathered together rocks and dust and rubble and hamsters or whatever and coalesced it together, right?

That's why the earth is round because that's gravity's work. tumbling everything towards a smooth surface. And that's how the sun is formed. It's gravity compressing dust and gas until it gets hot enough to burn. So gravity is this very powerful force and has a lot of time. It's actually one of the weakest forces,

but over cosmic scales and all this time, it has enough power to pull all this stuff together and compress it into objects. So people thought maybe that's going to happen with the whole universe, man. Maybe the whole universe is going to come back together and compress back into a tiny dot. That would be pretty amazing.

Like a giant cloud dust, we all just kind of come get pulled together and we maybe come back down. That's one possible way that the future the universe could end up. That's right. Yeah. So option A was the big crunch. But people didn't know. Like, is there enough stuff in the universe? Is there enough gravity from that stuff to pull everything back together?

Because it could totally have been that the explosion was more powerful essentially than the gravity and the things spread out forever. Oh, that could happen. things are like a grenade out in space, it just blows up so violently that gravity is too weak to pull everything back together again. That's right, yeah. And that could have been the fate of the universe. It could be that the universe just keeps expanding things spread out and slow down. Like gravity is still slowing things down,

but it doesn't have enough power to stop it and have it fall back in. And so it could be that just spreads out forever, getting cooler and cooler and more distant. until something we call the heat death of the universe. That's when everything is the same temperature. Right. So physicists are like, are we ever going to be cool? That was a pressing question.

We'll know in about 15 billion years. Tune in to find out if physicists are ever cool. So that's, I mean, that is a very significant question, right? Like, we live in this universe. We kind of want to know. Like, where is this whole thing headed? Yeah, I wonder if it's interesting

to most people. To me, as a physicist, I think it's one of the most interesting questions like what is the future of this whole amazing beautiful experiment we're living in right you know is it going to go on forever isn't it going to tear itself apart isn't it going to crunch together like to me that's a really interesting question like do we live at the peak of it or are we like in the after party you know what i mean like or are we or are our great grandchildren going to be like at the peak of the universe yeah i think that's exactly right and i think there's an issue of context there right Like, as humans, we are always striving to understand the context of our existence.

Why is this important? What's going on? And one of those questions is, like, is Earth at the center of the cosmos? Is Earth even important? And another question is like that, but in time, right? Like, are we living at an important time? What is the future going to be? Like, where do we fit in?

Yeah. Are people in a billion years going to look back and say, man, I wish I'd lived when Daniela Jorge were doing their awesome podcast. Because those were the days, man. Those were the good old days of the universe. Yeah, this podcast is peak civilization right here. I think that's what we're saying. I think our next podcast is peak civilization.

So stay tuned. Stay tuned for that one. Let's take a quick break. December 29th, 1975, LaGuardia Airport. The holiday rush. Parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal.

Apparently, the explosion actually impelled metal glass. The injured were being loaded into ambulances. Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat that hides in plain sight that's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.

My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Well, wait a minute, Sam, maybe her boyfriend's just looking for extra credit. Well, Dakota, it's back to school. on the okay story time podcast, so we'll find out soon. This person writes, my boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now, he's insisting we get to know each other, but I just want her gone. Now hold up. Isn't that against school policy? That sounds totally inappropriate. Well, according to this person, this is her boyfriend's former professor and they're the same age. And it's even more likely that

they're cheating. He insists there's nothing between them. I mean, do you believe him? Well, he's certainly trying to get this person to believe him because he now wants them both to Meets. So, do we find out if this person's boyfriend really cheated with his professor or not? To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. Hola, it's Honey German, and my podcast, Grasas Come Again, is back. This season, we're going even deeper into the world of music and entertainment, with raw and honest conversations with some of your favorite Latin artists and celebrities. You didn't have to audition?

No, I didn't audition. I haven't auditioned in, like, over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We've got some of the biggest actors, musicians, content creators, and culture shifters sharing their real stories of failure and success.

You were destined to be a start. We talk all about what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing vivras you've come to expect. And of course, we'll explore deeper topics dealing with identity, struggles, and all the issues affecting our Latin community. You feel like you get a little whitewash because you have to do the code switching?

I won't say whitewash because at the end of the day, you know, I'm me. But the whole pretending and code, you know, it takes a toll on you. Listen to the new season of Grasas Has Come Again as part of My Cultura Podcast Network on the IHart Radio app, Apple Podcasts, or wherever you get your podcast. Yeah, so people were thinking about those two options, right? Big Crunch or Heat Death of the Universe. So option A, everything comes crashing back down. Option B, things just kind of float away.

Yeah, exactly. And so what they wanted to do was look back in time, because you can't actually see the future. But it's not that hard in physics to see the past, especially in astronomy. To see the past, all you have to do is look out into space. And everything you see in space happened in the past, just because it takes light time to get here from there.

It's like back in the day when there was no email or internet, you would get your news from mail letters, right? And so the further way you get a letter... What did that actually happen? At some point, the internet did not exist, Daniel. What? What? What?

It was all dark... Dark male. Yeah, dark mail. So, yeah, so like the further away you get a letter, the older that news was. Yes, exactly. And some people think, oh, that's a bummer. I think it's actually pretty cool because it lets us look into the past. And so the further out you look, the further in the past you can see.

And the goal is to see like how fast is stuff moving away from us, you know, the expansion in the universe, how fast is stuff moving away from us now and how fast was it moving away from us earlier so we could understand like how is this changing? What is the fate going to be? Is it slowing down? How fast is it slowing down? Yeah. So because like if the fate of the universe was for it to crunch down, then you would see things

kind of expanding slower now than before. Like before things would be flying out and now they would be kind of slowing down and so we could expect things to crunch or if we measure things to be moving at about the same now as they were before then maybe the fate of the universe is just to kind of keep floating off and getting cooler.

Exactly. And so that was the question. They were like, let's look and see how things are changing. How much is it slowing down? Is slowing down a lot, which means maybe big crunch or slowing down just a little, which means maybe heat death? That was the question they asked. But it's actually fascinating how they did it because it's tricky.

In order to know how far back in the past you're looking, you have to know how far away a star is. And that's not easy to figure out. Right. Because if you look at a star, if it's dim, you don't know if it's just like a weak star or a really far away star. It's just a little point, right? It's hard to tell.

You can't tell how far away it is just from how bright that point is. That's right. You can't tell the difference between a star that's very bright and far away and very weak and close up. We have some tricks, but none of them are really good. The early days, people used to figure out how far away stars were by seeing how they shifted as the earth went around the sun. Because if something was really close,

then you could see it sliding back and forth as the earth went around the sun. That's called the parallax system. It's like how you triangulate with your eyes, right? If something looks really different when you wink one eye and you wink the other one, then it must be pretty close. but if it doesn't change a lot when you wink between eyes, then it's far away.

Yeah, and so that's the original way people can figure out how far stuff away is. And then it was like in the 1920s when Hubble figured out a new way to look at stuff in the sky, and he found a particular kind of star called a C-Fid that rotated, and its brightness was connected to how fast it was rotating. So you could figure out by measuring its rotation how bright it is, which told you how far away it was. So he was the first one to be able to see things that were further away.

And he's actually the one who figured out not just that the universe is expanding. Before that, people thought, oh, the universe is just a bunch of stars hanging in space. And he figured out two amazing things. One is the universe is expanding. And the other is that the universe

is more than just our galaxy. And what do you mean more? He figured out that there were other galaxies. That's right. Before Hubble, we thought there is just our galaxy. Like imagine just a single galaxy floating in space.

that's what people thought the universe was and he saw these little smudges up in the sky that people thought oh these are just dust or clouds or something turns and that he proved by measuring the distance to them that they were way too far away to be part of our galaxy he proved that they were actually other galaxies

and that those galaxies who were running away from us it must have been so mind-blowing to be Hubble to have this moment of realization to understand this huge context of our existence Yeah. It must be very humble to be Hubble. You know, I don't know anything about Hubble, but a lot of these famous physicists were not the nicest of guys. Oh, really? Is that true? Are there stories about Hubble? I don't know any of them, but if I had to guess, any random famous physicists from history, probably got there by not being the nicest of a person.

Not being humble. Anyway, Hubble was able to see past our galaxy, but cosmically speaking, that's not far enough to be able to tell. Because that's just like the last, you know, a little bit of the history. Then it was in the 1990s, people developed a powerful new technique that let them see much further so we could tell how far away things were that were much, much, much further. And that gave us a much deeper view. Further than like the nearest galaxy. Yeah, really far away galaxies.

And that's a new kind of star that we started to understand called a Type 1A supernova. Right. They call them like the standard candles, right? Exactly. They're standard candles because they act the same way everywhere in the universe. And so we can tell, we know how bright they are. So based on how dim they are or how bright, we can tell how far away they are. So it was in the 90s, people figured this thing out. They're like, ooh, look, we have a new standard candle that lets us look much deeper into the history of the universe. Now we can answer this question. We can figure out, what is the future of the universe? What is it going to be? So most stars are, you can't really tell, right? Some of them are dim, some of them are far away, but there are this special type of star. It always explodes the same way

so that if you see it really bright and must be closed or if you see it really dim, it must be far away, right? That's right. And these are not just stars, as you said. These are supernova, being the end of stars, right? That's when stars collapse and implode followed by a huge, enormous cosmic explosion. And that explosion is super bright, like a single supernova.

can outshine the entire galaxy it's in. But just for a few days, it's like crazily burning up all of its fuel. It's like a flare. If you sit your house on fire, it's brighter than the whole neighborhood, right? But not very long. So there were, you know, people figured this out, and then people sort of split into two teams. It was a team at Berkeley and there was a team in Australia.

And they were racing to discover, to get as much data as possible. Because supernova are not regular. It's not like you know when it's going to happen. You have to just scan the sky and hope to see what. to see one. And it developed special technology to look through all this telescope data and try to find new stars that were appearing in the sky. Because that's what a supernova looks like. It looks like a bright new star that appears and then it fades over a matter of days. And if you capture enough data about it, then you can learn about its brightness and figure out how far away it was. And so finally, one of them discovered, like, hey, we have a measurement for how the universe is expanding, whether it's expanding faster or slower than before. Yeah, it took a couple of years for them to have enough data, and it was a scramble. I think those people must have been working 20-hour days in the 70 days a week.

Everyone wanted to be the first to say, like, hey, here's that measurement. Exactly. Finally, they had this plot of how fast the universe is expanding as a function of time. And what they discovered is that the universe is not slowing down a lot or slowing down a little. So it's not option A nor option B. That's right. The universe went for secret option C. Secret option C.

You didn't even know it was on the menu. That's what we got for dinner, right? And I love when the universe does that because it's like, oh, you silly little humans, you have no idea what even question you're asking. You hadn't even thought about this answer. That's right. And so secret option C is that the universe,

the expansion of the universe is not slowing down at all. It's increasing. It's getting faster and faster. It's accelerating. So the fate of the universe is not that it's going to crunch down or just float away. things are like raising away from each other. That's right.

Faster and faster every year. Something out there. We don't know what it is. We can't explain it. We don't understand it at all. Something out there is pushing all of these other galaxies away from us, and it's doing it faster and faster every year. You only need to know a little bit of physics to know that accelerating an entire galaxy,

hundreds of billions of stars, takes a huge amount of energy. That's why we were talking earlier about how it's two-thirds of the energy in the universe, because it's not a small feat to expand the whole universe faster every year. Yeah, it's like these galaxies want to get together because of gravity. They're pulling on each other to get closer, but something is actually pushing them apart. That's right. And that's the thing we call dark energy.

So they discover this thing, total mind blow, like what the universe is totally different from what we thought it was. The fate of the universe is different from what we possibly imagined. Then there's the second big question, which is what is it, right? We found it. We know that it's there. We see that it's happening, but we don't understand it at all.

We just observe it. Okay, but before we get into that, let's take a quick break. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., every day. changed. There's been a bombing at the TWA terminal.

Apparently, the explosion actually impelled metal glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat. that hides in plain sight that's harder to predict and even harder to stop listen to the new season of law and order criminal justice system on the iHeart radio app apple podcasts or wherever you get your

podcasts my boyfriend's professor is way too friendly and now i'm seriously suspicious oh wait a minute sam maybe her boyfriend's just looking for extra credit well dakota it's back to school week on the okay story time podcast so we'll find out soon this person writes My boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now, he's insisting we get to know each other, but I just want her gone. Now, hold up. Isn't that against school policy?

That sounds totally inappropriate. Well, according to this person, this is her boyfriend's former professor, and they're the same age. And it's even more likely that they're cheating. He insists there's nothing between them. I mean, do you believe him? Well, he's certainly trying to get this person to believe him because he now wants them both to meet. So, do we find out if this person's boyfriend really cheated with his person? professor or not. To hear the explosive finale, listen to the OK Storytime podcast on the IHeart

Radio app, Apple Podcasts, or wherever you get your podcast. Hola, it's Honey German, and my podcast, Grasas Come Again, is back. This season, we're going even deeper into the world of music and entertainment with raw and honest conversations with some of your favorite Latin artists and celebrities. You didn't have to audition? No, I didn't audition. I haven't audition in like over 25 years. Oh, wow. That's a real G-talk right there. Oh, yeah. We've got some of the biggest actors, Musicians, content creators, and culture shifters sharing their real stories of failure and success.

You were destined to be a start. We talk all about what's viral and trending with a little bit of chisement, a lot of laughs, and those amazing vivas you've come to expect. And of course, we'll explore deeper topics dealing with identity, struggles, and all the issues affecting our Latin community. You feel like you get a little whitewash

because you have to do the code switching? I won't say whitewash, because At the end of the day, you know, I'm me. Yeah. But the whole pretending and cold, you know, it takes a toll on you. Listen to the new season of Grasas Has Come Again as part of My Cultura Podcast Network on the IHartRadio app, Apple Podcasts, or wherever you get your podcast. That's what dark energy is. It's like that thing that is pushing all the galaxies apart.

That's right. The totally unexplained, ununderstood phenomenon, which is sure. shredding the universe and causing it to explode and changing its future. That's what dark energy is. And most people walking in the street have no idea. It's like the phenomenon of the universe expanding faster and faster. That's dark energy. That's exactly right.

It's not like some kind of like actual like energy like a photon or some kind of like thing. Like we really don't know what it is. All we know is that it's energy. That's all we know. And we know that it's accelerating the universe. And a fascinating thing is that it's not just pushing. stuff through space, right? One way to imagine a galaxy moving away from you

is that it's moving through space away from you, right? And that's what you imagine probably when you think of the Big Bang. Everything comes out of this tiny little ball and expands through space. But dark energy is doing something else. It's also creating new space between us and the other galaxies. It's not just pushing things through space. It's making new empty space.

It's not pushing you and me apart from each other. It's like it's creating more... room, more land in between us. That's right. It's making the 405 even longer. Well, you know what I mean? Like a tectonic plate, you know how it comes up and it creates land and it pushes things apart? That's kind of what dark energy is doing out in space. Yes, exactly right. Creating new real estate in between you and me. That's pushing me further apart from you.

That's right. And it's hard to think about what it means new space. What is that? Unless you think about space in a different way. isn't just emptiness or nothingness, as we've said on this podcast a few times. It's this dynamic physical thing. And this is one reason we think it's more than just emptiness is that it can do this thing that emptiness can't, which is create more of itself. It's not nothing. It's like real estate and there's more of it being created. That's right. Location, location, location. You know, it's the most important thing, right? And new space is being created all the time. And that's what dark energy is doing is creating this new space. And we don't have any explanation for it. You know, people think about

theories of what is dark energy? Could it be this? Could it be that? One idea that physicists like is to think about the energy of this empty space. Like maybe space itself has energy. Maybe space can never really be empty. It's full of the Higgs field and it's full of virtual particles and it's full of all this little quantum frothing bubblyness, right? Like by its very nature is just like this has a bubbly personality. That's right. Space isn't cold. It's more friendly. It wants to have more of itself. It's social. And so one idea maybe dark energy is this energy of empty space. The problem is if you sit down to do the calculations,

you say, all right, well, let's calculate how much energy there is in empty space. And compare it to what we see, you come up with a number that's way off, like not a little bit off, off by 10 to the 60. And that's 10 with 60 zeros beyond it. That's a big error. That's a pretty big mistake. So the other fascinating thing is that it hasn't been doing it forever. It turned on about 5 billion years ago and started this acceleration.

And again, we don't know why. We don't know what turned it on. We don't know what we turn it off. You know, what is dark energy like? You know, long walks on the beach. I don't know. We don't know very much about it. Was it always there from the beginning of the Big Bang?

It's just somehow, five billion years ago, it started pushing things more actively. Yeah. These days, the most modern picture of cosmology, I think, considers the Big Bang and Dark Energy to be sort of connected. Like, imagine a huge expansion in the universe in the very first few moments that we call the Big Bang. bang, or these days we call that inflation, and then that's stopped.

And things just sort of floated through space for a while. And then five billion years ago, it started again. So in one sense, you could think of dark energy as like phase two of the big bang or the big bang continued, you know. But just when you thought it was safe to get into space, here comes the dark energy. Here comes the bigger bang. Yeah. Both of them are expansions of space.

We think they're probably related, but we don't really know how or why. They kind of do the same thing, but who knows why I would take a nap for, billion years. That's right. What were you doing? How do you have to be able to your time? Are we getting built for that time? Yeah, exactly.

And there are big consequences for the fact that it's not just pushing things through space, but actually creating new space. Yeah, because we started as a podcast asking, like, what is going to happen to the universe at the end until it has, you're saying it has big consequences for, like, what's going to happen to the universe. Yeah, because it's creating new space, which means it's effectively evading the speed limit of the universe, the speed of light, right? Nothing in the universe can move

through space faster than the speed of light, right? That's a hard and fast limit. And so these galaxies can't move through space away from us faster than the speed of light. But there's no limit on how fast you can create new space. And so new space is being

created between us to these other galaxies faster than light can go through it. It's like if I was trying to get to you down at Irvine, and I can only go 70 miles per hour in the highway, you know, nominally. You'd be lucky to go that fast in the 405. Let's say it's like 2 a.m.

You have your own private lane? Let's say I was using the carpool lane. But yeah, but let's say that a new land was being created between you and me faster than 70 miles per hour. I would never get to you. That's right. If they're just laying new road and faster than you're driving through it, you'll never get down to Irvine. Exactly. Right.

And that's a situation. Those photons that are leaving those galaxies now will. never reach us because the space between us is growing fast and the photons go through it. Right. At some point they'll stop reaching us, right? Like we'll see them and then suddenly they'll blink out of existence. Exactly. Things that used to be in our observable universe, things that we see now because light has had a chance to get through the universe to us, will no longer be observable because dark energy is pushing them out of this sphere of the observable universe, all the stuff we can see because light has had a chance to get to us.

galaxies in the sky are disappearing. Right now. Right now. Quick rush outside to see them before they disappear. Things that are on the edge of our observable universe are disappearing because dark energy is pushing them beyond the bounds of things we can see. So the night sky is getting darker and darker. So like if you hit the fast forward button on a camera point in the sky, you would see stars

just snuff out, just like poop, boop, boop. Yeah, you would see galaxies snuff out. Of course, there are clusters of stars. And so in that scenario, all these galaxies snuff out. snuff out of the sky, right? They get pushed out beyond our observable horizon, and they disappear. And then we're left with the single galaxy in the universe, just like people before Hubble thought, right? And imagine astronomers in the future, right? After all those galaxies are pushed out. They're going to think we're the only, there's only one galaxy in the entire

universe. Yeah, because it would be the only thing they could see, right? It's amazing to imagine how, to try to think about, how could they learn about the universe if all they could see was their galaxy. How could they even possibly know, right? They would have no idea how big it actually is. Yeah, they would have no idea what's beyond their observable universe. And that's really humbling because it reminds you of how little we know, right? We're, after all, 14 billion years into the history of the universe.

There could be fascinating clues about the way the universe works and what it's made out of that have already been pushed beyond our sky that we cannot see and we will never see. right so what's lost in the night sky well we have no idea right there could have been weird kinds of galaxies who knows that we can't see anymore yeah exactly and continue it even further and remember dark energy is not just out there in space it's here it's with me it's with you it's literally pushing me and you apart right now the reason we don't see it is because we have bonds that are holding us together right like their dark energy is trying to create new space between the molecules in my hand but the molecules are bound together tightly enough to resist that

But if dark energy continues, it might eventually shred the Milky Way, right? Take our own galaxy and toss the stars out into space. Eventually, we might just be a solar system floating in the inky blackness of space seeing nothing, right? That's one potential future. Thinking that we're the only star in the entire creation, right, the entire universe. That's right. That's one real possibility now. Again, we don't know what dark energy is going to do. We don't know if it's strong enough to do that.

We don't know if it's going to stop. We don't know if something else is going to happen. We really have no idea. But it's amazing to me that this knowledge is only 20 years old. 20 years ago, before we discover this stuff, we didn't know that the universe was accelerating. And we didn't know that most of the universe was this thing called dark energy. Like, think about how recent that discovery is.

Yeah. That to me is inspiring because it makes me hope that we have more mind-blowing discoveries ahead. You know, more of these moments of like, what? The universe is totally different from what I imagined. That's what I live for in physics. Well, you know, this was making me think this past weekend I was camping with my kids and my family. And it was a beautiful night. You could see all the stars.

And I pointed out to my daughter, it was like, look at all the stars. And I was pointing out some of the constellations and stuff. And she's like, whoa. And I pointed out the big dipper. And she's like, that's the big dipper. and she proceeded to tell me this whole complicated story about the Big Dipper that she read in this book

she had at school that she's read like a million times but for the first time she'd actually seen the stars she'd actually seen the Big Dipper What a fun moment for her, yeah to make these things real. Yeah, yeah. And so yeah

so I think that's a big lesson you know, go out there, look at the stars before they go away. And this is not abstract. I mean this is our universe we're actually talking about it. You can go along and live your life and worry about traffic and paying the next bill and your own financial big bang.

But these things are our context, right? This is the universe we live in that we're desperately trying to discover before it blows itself up. It's changing all the time. So go out there and experience it. Absolutely. If you still have a question

after listening to all these explanations, please drop us a line. We'd love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge, that's one word, or email us at Feedback at danielandhorpe.com. Ah, come on, why is this taking so long? This thing is ancient.

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Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend's been hanging out with his young professor a lot.

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