Daniel and Kelly’s Extraordinary Universe - Listener Questions: photon information, simulated Universes and Daniel's fantasy science budget

Episode Date: July 1, 2021

Daniel answers questions from real listeners like you. Submit your questions to [e-mail] 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. Now, 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. I'm Dr. Scott Barry Kaufman, host of the Psychology Podcast. Here's a clip from an upcoming conversation about how to be a better you. When you think about emotion regulation, you're not going to choose an adaptive strategy, which is more effortful to use.

use unless you think there's a good outcome. Avoidance is easier. Ignoring is easier. Denials is easier. Complex problem solving takes effort. Listen to the psychology podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Every case that is a cold case that has DNA right now in a backlog will be identified in our lifetime.

On the new podcast, America's Crime Lab, every case has a story to tell. And the DNA holds the truth. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, gotcha. This technology is already solving so many cases. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. When you were a kid, did you ever dream about being the president?

and maybe you were attracted to the personal jet or to the bulletproof car or the free housing or the sheer fame and power of the position. I was recently surprised to learn that most of today's kids don't want to be president. Only one quarter of 10 to 16 year olds recently surveyed said they had presidential aspirations. And when they asked kids what they did want to be when they grew up, president came in last. It was tied with alien. Now, I have no personal interest in being president. sounds like a stressful thankless job. I'd rather win a Nobel Prize than a presidential election.

But it makes me wonder what it would be like if we had a scientist president. Would they be tempted to fund a lot more science like a lot more science? And you might be wondering how many black hole creating particle accelerators does one planet need anyway? My answer is let's elect a scientist and find out. Hi, I'm Daniel. I'm a particle physicist and I'm a big booster of spending money on science. Not just because I'm a scientist and I benefit directly from all that funding, but because there are so many things out there in the universe,

we could learn if we just spent the cash. We are living literally in a store of science. knowledge and we are being very, very stingy with our spending. So many deep secrets of the universe we could unravel if we only loosened our wallet and spent a little bit more money on science. And we wouldn't even need to spend less money on other things. But welcome to the podcast, Daniel and Jorge, Explain the Universe, in which we take you on a mental journey through all of the things that we do know and all of the things that

science is still trying to figure out. We are not shy. We tackle the biggest questions in the universe. universe. Why is it here? What's going to happen to it? How does it all work? From the tiniest little particles vibrating in your fingertips to the massive, incredible climactic collisions of galaxies. We talk about all of it. And most importantly, we make banana jokes and try to make all of it accessible to you. Usually on the podcast, I'm here joking around and explaining science with my friend and colleague Jorge Chan, creator of PhD comics. He couldn't be with us here today.

So I'm taking the opportunity to catch up on questions from our listeners. We are always asking questions on this podcast and sometimes answering one or two of them, but we also encourage our listeners to ask questions because science is not something done just by people wearing white lab coats and eye protections in silly looking labs and movies. It's something we all do. The process of science is simply just some mental instrument for accumulating knowledge, for diving into these puzzles that everyone wants the solutions to. What does it mean to be a human in this universe depends on which universe we are in and how it works. And as through history, we have learned more and more about the universe, it's changed what it meant to be human. Frankly, it's made us feel

less and less important and less and less central, but at least we know the truth. At least we know where we stand and where we don't stand in the universe. So if you're the kind of person who wants to know answers to deep questions about the universe, you are definitely in the right place. and you are welcome to send us your questions. If we haven't tackled it on one of our almost 300 episodes of this podcast, you're welcome to send us a question to questions at danielanhorpe.com. Most of them I will answer almost right away. You are guaranteed a response.

And some of them I will put right here on the podcast and discuss in more depth because I think that other people might also want to know the answer to these questions or I just think they're super fun and I want to talk about them. So today on the podcast, we have more listener questions. Today we have super fun questions about photons, we have questions about simulated universes and we have questions about what to spend science money on. So without further ado, let's dive right in and get to our first question. This is a question from Brad from Montana.

Brad is actually an artist who carves wooden spoons and other things. I checked out his website. It looks pretty cool. You all should check it out. Anyway, here is Brad's question. It's more so like a series of questions and just an expression of not knowing what's going on here than it is just one specific question. But it seems like almost every bit of knowledge we have about the cosmos in the universe,

we have learned through interpreting light and the information that's, in light, which as far as I know is just photons. And what I don't know is how exactly on the I want to say microscopic, but that's not even it. On the atomic level or the subatomic level, how is that light actually made and how does the information get in there to the photon? Is it the frequency of which something is vibrating when it emits the light, or is it some other property inherent to the photon that has traveled millions and millions of light years to get to us. It seems like a photon is this weightless, massless thing going at the speed of light, but it can have so much different information in it. There must be something that

it's doing that would make one piece of light different than another piece of light. Like what is the photon actually doing differently that makes it have different information? in it. And so I'd love to know that. And then on the very subatomic level, how do those photons get kicked out from whatever they're getting kicked out on? I would just love any information on that. Hope to hear it on the pod someday. Thanks. I love the pod. Listen to every episode. Thanks, guys. All right. That was an awesome question from Brad. I love how he's thinking about the way we learn what we learn, because it's really amazing when you think about it for a moment, how much we do know about the universe, never having left this tiny little rock. We know so much about

the solar system, about the structure of the galaxy, about nearby galaxies, about the whole galaxy cluster, about super clusters of galaxies, and the incredible sheets and filaments that they form at the very, very largest scale of the universe. And of course, no human has ever even left the vicinity of Earth. So it's incredible that we've learned so much, and you're totally right, Brad, that almost all of that information comes to us in the form of light. Just by opening our scientific eyeballs and receiving that light, we are getting so much information about the structure of the universe. So the way I take your question is, how is that information encoded?

First of all, what makes that light? How is it made? How does it pass to us through the universe? And then how do we figure out what it means? How is a photon actually storing information? So I think the first thing to do is to understand what we, mean by a photon. And remember that photons are all just wiggles in the electromagnetic field. They're all just different kinds of electromagnetic radiation. And you're very familiar with

electromagnetic radiation. Light, for example, from your light bulb is EM radiation. And it's different from, for example, x-rays that the doctors use to see your insides, but they are both electromagnetic radiation. The difference between visible light and x-rays and gamma rays and infrared and radio is just the frequency at which those photons are wiggling. So they all travel at the same speed. The speed of light is the speed of light. It's always the same. But the photons wiggle at different frequencies, which means conversely they have different wavelengths. So at the very long wavelength, like infrared and radio, these things don't wiggle as often. So the wavelength is longer, even though they're moving at the same speed. And then at the very, very high frequency,

the short wavelength, we have things like ultraviolets and x-rays and gamma rays. We divide these things up and give them different names, mostly because historically we discovered them in different ways and experienced them in different ways. Like x-rays were discovered by Runken and we have a whole fun podcast about exactly how that happened. And qualitatively, they are different from visible light because we didn't know they existed for a while and they can do things visible light can't. But conceptually, they're really just all different kinds of photons. So when we look out at the night sky, we receive photons from space, What information is encoded in those photons?

Well, a photon is a photon is a photon. The only difference really is the frequency. So you get a photon from space. You can measure its frequency. You can say, oh, that was a red photon or that was an infrared photon or that was a radio photon or a gamma ray photon, for example. You can measure the frequency of a photon by measuring its energy, right? Because the speed of the photon doesn't depend on the frequency. it's all the same, but the energy of the photon is linked to its frequency.

There's this expression, energy is Planck's constant times the frequency. And so by measuring the energy of the photon, you can tell what its frequency is. And that's basically the information that a photon carries. You know what direction it came from and what frequency it has. And that's all the information. Now, technically, there's another layer of information there because photons are bosons and they have spin, and you can tell how they're spinning also. That's not a level of information that we typically know how to take advantage of in astronomy,

though there are some applications of measuring the spin and the polarization of those photons, which can take advantage of it. So you ask like how a photon can store so much information. The photon itself can't store that much. And you know, it is a massless particle. It is this tiny little wisp of energy. But the fact that that energy was made and is coming to us from a certain direction, that's also a lot of information, right?

the context tells you something about it. Like if you look up in the night sky and you see a bunch of photons of the same frequency all hitting your eyeball, what do you know? Well, you know there are a bunch of photons coming from the same direction, but also you can infer that there's something there. There's something out there generating those photons at a specific frequency. And that gives you a clue. It helps you sort of unravel an astrophysical mystery and say,

well, what do I know that's capable of generating those photons? So that goes to the other part of your question, which is, what can make these photons? How are they actually made? And how does that tell us about what's doing the photon making? Let's remember again what a photon is. It's a ripple in electromagnetic fields. How do you make ripples in electromagnetic fields? Well, one way you can do it is you take a charged particle like an electron.

Electron just sitting by itself has an electric field, right? For example, it will repel another electron. It will attract a positively charged particle. So just put an electron in space and it has an electric field. Now take that electron and move it, right? Wiggle it. What happens to the electric field? Well, electric fields don't instantly move.

If you slide that electron one meter to the left, the electric field like a mile away or a kilometer away doesn't instantly change. It takes a moment for that information to propagate through the electric field. And if you slide the electron to the left and then back again and to the left and to back again, what do you get? You get ripples in the electric field, right? Because you are moving the electron. And it's just like if you put ripples in water, right?

Tap your hand into a bathtub and make ripples in the water. Those ripples have a frequency. It's the frequency at which you are tapping the water. Same way, you take your electron and you wiggle it in space at a certain frequency. What are you doing? You're generating electromagnetic radiation. Those ripples in the electric field are electromagnetic radiation at a specific frequency. So you are creating photons by dialing up the frequency that you are wiggling the electron.

And this is how an antenna works. An antenna is just a long column with a bunch of electrons in it that we can control their wiggling. We can say, all right, wiggle at this frequency. Now stop. Now wiggle at that frequency. Now stop. And when they do that wiggling, they generate photons at the frequency that they are wiggling. So if your electrons are moving at 4.2 megahertz, for example, then you will be generating photons at that frequency.

And that's also how an antenna works to receive messages, right? The photons come in, which are just wiggles in the electric field, and they wiggle the electrons in the antenna at their frequency. And we can measure the wiggling of electrons in a metal antenna, right? That creates a current, an oscillating current, which we can measure. So that's how we receive and send photons because they really just are ripples in the electromagnetic field. So that's how you could make a photon of any arbitrary frequency that you want. But there aren't like antennas out there in space sending us these messages.

At least we haven't received any yet. Instead, what we have are natural objects like stars or like clouds of gas or quasars or black holes or accretion disks. These things are sending us radiation. How does that happen if there are not antennas out there? How are they sending us photons? Well, the picture I told you a moment ago of a single electron in space is simplified. These electrons do exist, but they exist inside matter.

An electron that's, for example, captured by a nucleus can't just wiggle in any arbitrary frequency. It has energy levels due to quantum mechanics. And so what it can do is it can orbit the atom at a certain energy level. And it can orbit the atom at another energy level. And when it moves between one of those two, it can emit a photon. So, for example, if you have a gas, which is really, really hot, meaning it has a lot of energy in it, then the electrons inside it are excited. There are some high energy level.

When they jump down to a lower energy level, they give up some of their energy. How do they do that? They do that by emitting a photon. A photon carries away some of that energy. And the frequency of that photon, again, is connected to the energy of the photon. There's a relationship there. The energy is Planck's constant times the frequency. So if there's a specific energy gap for an atom, it can only generate photons of that frequency.

And that's how we can tell what's out there. So you get, for example, a bunch of photons at a specific frequency, you can say, oh, that's hydrogen over there in that cloud that's getting really hot and then cooling down and sending us photons. So just from the frequency of light, you can tell what it is that's emitting. And this is super important and super powerful information. And it's true about almost every kind of material. If you take hydrogen, for example, it tends to emit at several different frequencies. Those frequencies correspond to an electron jumping down one energy level or two and a number. energy levels or three energy levels or from energy level three to two, for example.

There's a spectrum. There are a series of lines that are like a fingerprint that tell you this is hydrogen. So a hydrogen cloud doesn't just emit at one frequency, emits at a set of frequencies, which are unique to hydrogen because helium and other elements have different energy levels and they emit at different frequencies. And so you can get a whole bunch of light from a cloud. You can tell, oh, look, it's mostly hydrogen, but there's some helium and a little bit of lithium and all this kind of stuff. And that's how we can tell the molecular composition of

what's out there just by looking at the frequencies. So these frequencies contain so much rich information if you also have the context of understanding how to make light at those various frequencies. It also super interestingly works the other direction. If you have a source of light, like a star that tends to emit almost every frequency and you put a cloud of gas in front of it, what happens? Well, that cloud of gas will absorb some folks. But which ones? Only the ones that correspond to the energy levels of the electrons inside of it. So, for example, a cloud of hydrogen will tend to absorb photons at only those frequencies

that match its energy levels. So what do you get from the other side is you get a broad spectrum of light almost every frequency with some gaps in it. And those gaps are exactly at the same frequencies you would get if you took the hydrogen, heated it up, and let it emit. So those things match perfectly. It's a really nice little sort of. key and lock kind of situation. But there's even more to it than that because these different

frequencies let you see the universe in different ways. Just the same way that like visible light gives you one picture of the universe, but x-rays give you a different picture of the same things around you, right? If you look at your arm in visible light, you see the skin. Why is that? Because mostly your body is opaque to visible light. The visible light is absorbed by your body or reflected by it. It's not transparent to visible light. But x-rays can pass through your body without being absorbed because they're not of the frequency that your body can absorb. So they can pass right through you, except of course some things inside you which do tend to absorb x-rays. And so x-rays will let you see through your body in a way that visible light can't. We can do exactly the same thing with

different frequencies of light and apply it to the whole universe because there are lots of different things out there in the universe and some of them are transparent to visible light and some of them are opaque to visible light like huge clouds of gas and dust mostly absorb visible light and so if you want to see for example in the center of the galaxy where things are very crowded and there's lots of gas and dust and it's choking things up and it's hard to see what's going on in the optical spectrum you can use other frequencies of light you can look for photons in other frequencies which are not as easily absorbed by gas and dust and specifically longer frequency photons photons in the radio spectrum or in the infrared are not as easily absorbed by gas and dust

and so it's easier to see through those clouds so if you like put on a different filter you can see through stuff that was blocking your view so i think that's super cool because it lets you see different things in the universe also things tend to radiate light depending on their temperature. So the hotter something is, the higher the frequency light that comes from it. That's why the sun, for example, emits in the visible light. The earth also glows. It just doesn't glow in the visible light. It glows in infrared because the earth is cooler than the sun. And so it emits light at lower frequencies. So it's sort of like a star glowing at a frequency that we can't even see. But if you turn on a telescope like the James Webb

Space Telescope that can look in the infrared, then you can see these things which are otherwise invisible to the naked eye, like planets don't glow in the visible. So if you use Hubble, you can't see them. But if you use the James Webb Space Telescope, you can pick up photons in the infrared spectrum and you can see colder things, huge clouds of gas and dust and also maybe even planets. One last comment I want to make is that you are right that almost everything we've learned about the universe, we have done so using light, using electromagnetic radiation. It's very powerful. But it's not the exclusive method by which we get information about the universe, right? We also can get information using gravitational waves. These are these weird ripples in space and time

created when, for example, black holes orbit each other and fall in and merge. And that's a very different kind of radiation. It's not a ripple in the electromagnetic spectrum. It's a ripple in the fabric of space itself. So it's similar in that it is a wiggle in something and it's a radiating. but it's not radiation of photons. We don't know if gravitational waves are made of quantized gravitons yet, but we have seen gravitational waves. They are real and they are not photons. Also, we can look for particles from space,

which are like ripples in matter fields. For example, neutrinos are a very powerful way to probe what's going on in the universe. They are these incredible messengers because they can pass through almost everything. And so we can use other kinds of particles to understand what else is going out there in the universe. And these days, we call that multi-messinger astronomy. It's a very cool way to see the universe with different kinds of glasses on. The more eyeballs you turn onto the universe, the more you learn about it. All right. So thank you, Brad, for that super fun question for letting me talk about the exciting things we can learn about the universe using

photons. I want to answer a couple more questions, but first, 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, 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 2, 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 week on the OK Storytime 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.

former professor and they're the same age. 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 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. Hey, sis, what if I could promise you you never had to listen to a condescending finance, bro, tell you how to manage your money again. Welcome to Brown Ambition. This is the hard part when you pay down those credit cards.

If you haven't gotten to the bottom of why you were racking up credit or turning to credit cards, you may just recreate the same problem a year from now. When you do feel like you are bleeding from these high interest rates, I would start shopping for a debt consolidation loan, starting with your local credit union, shopping around online, looking for some online lenders because they tend to have fewer fees and be more affordable. Listen, I am not here to judge. It is so expensive in these streets.

I 100% can see how in just a few months you can have this much credit card debt when it weighs on you. It's really easy to just like stick your head in the sand. It's nice and dark in the sand. Even if it's scary, it's not going to go away just because you're avoiding it. And in fact, it may get even worse. For more judgment-free money advice, listen to Brown Ambition on the IHeart Radio app, Apple Podcast, or wherever you get your podcast. A foot washed up a shoe with some bones in it. They had no idea who it was.

Most everything was burned up pretty good from the fire that not a whole lot was salvageable. These are the coldest of cold cases, but everything is about to change. Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. A small lab in Texas is cracking the code on DNA. Using new scientific tools, they're finding clues in evidence so tiny you might just miss it. He never thought he was going to get caught. And I just looked at my computer screen.

I was just like, ah, gotcha. On America's Crime Lab, we'll learn about victims and survivors. And you'll meet the team behind the scenes at Othrum, the Houston Lab that takes on the most hopeless cases, to finally solve the unsolvable. Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. All right, we're back in. It's Daniel answering listener questions from our wonderful, good looking, intelligent, clever, friendly listeners who send in their deep thoughts about the universe. I love hearing from all of you guys. Please, please, please, please write to us. I know that you are out there. You have questions about the universe and you have not written to us. And I don't know why. So please send us your questions to questions at Daniel and Jorge.com. I promise you.

you'll get a personal reply. Our next question comes from a pair of curious folks from Brazil. Hey guys, this is Rodrigo. I'm Brazilian, but live in the UK at the moment. I love the show and so does my 12-year-old son Pedro, right, Pedro? Right. I love the podcast too. And we have a question about the simulation hypothesis. Exactly. So our question today is whether the quantized nature of our universe and the fact that we observe a speed limit of sorts, which is the speed of light, might add to the probability of us actually being a simulation, since we could argue that bits or quanta and processing speed limits

are aspects we'd expect to observe in any computational system, and that might not necessarily be present in a real ultimate universe. That's it. We would love to hear your thoughts about that. Thank you so much and keep up the great work. All right. Well, this question, super fun, kind of silly, but also very, very serious. It goes to the heart of the nature of our reality. Are we living in a simulation? Are we living in a real universe? Could we tell the difference? So thank you very much, Rodrigo and Pedro for sharing your curiosity and the super fun question. And thanks to Rodrigo for sharing his love of science and deep thinking with the next generation. So let's first revisit the super fun question of are we living in a simulation? If you haven't heard this before, this is the idea

that maybe everything around us isn't real in some deep sense, but instead maybe maybe we are all inside a computer run by some other kind of creature in some other kind of universe. And the genesis of the idea comes from our ability to simulate universes. We have powerful computers now. And on those computers, we can run simulations. We can say, what happens if you take a star and you shoot it against another star? Or what happens if you have 10 to the six stars, do they form a galaxy? This is a very important part of doing science are these simulated experiments because sometimes things are just too complicated to write everything down with pencil and paper. And so we need to like code in the rules of the universe and then simulate it just to see what happens. This is often the case when we have a complex emergent phenomena, one that's difficult to predict from the underlying rules, but we can use a simulation to figure out what happens.

And the way the simulation works is you write the rules down, you specify the initial conditions, like you say, there's a star over here, there's a star over there, and there's a star over here. And then you say, go. And the simulation takes over and it says, well, I know where everything is right now. And I know what the rules are for how to update my universe. And it makes a little change in the universe. It says, all right, let's take a one time step forward by half a second or by two seconds or whatever. And I'll move all the stars a little bit. And then I'll do it. again. And in that way, you can describe really complicated things like hurricanes or galaxy formations, even if you can't ever sit down or write like the math directly for a hurricane or how a galaxy

forms. So it's a very powerful tool. But people notice that they're writing down basically the laws of physics into a computer. And they're creating inside their computer a simulated universe. And the idea is, what if you could write a simulation that was so complicated, so sophisticated, that it could simulate the workings of a human brain. Would that human brain think that it was alive? Would it think that it existed? Would it have a subjective first personal experience? That, of course, goes to the heart of the question of what is consciousness and is it just

information or does it rely on the actual configuration of our neurons? But imagine for a moment we put that impossible to answer difficult question aside and we assume that a perfect simulation of your mind would have exactly the same experience as you. it would think that it was alive. In that scenario, then you could imagine writing a simulation, which was so good that something in it would not know it was in a simulation. It would experience the universe that you have created inside your computer, and it would think it was real.

Now, if you believe that, then it only takes one more step to reflect it back on yourself and say, hold on a second, how do I know that the universe I'm living in isn't a simulation? Is it possible that I'm nothing more than information in some giant, incredibly complicated computer capable of simulating an entire universe? That's a pretty big idea holding your head and maybe it makes you a little queasy to wonder like who's out there, who's programming the universe. But it also kind of makes sense in some way because there is a similarity to the structure of a computer program and the structure of a universe, right?

The universe seems to follow rules. Like for reasons we don't really understand, the universe is describable using mathematical physical laws. And those physical laws don't seem to change. You do an experiment today and you do the same experiment in a month or in 100 years, you should get the same answer because you are probing some true physical law that governs what happens in our universe. That's also the same principle behind a simulation, right? You write down the laws of what happens and then it just sort of turns forward, implementing them mindlessly. So that's kind of cool. And it sort of feels like by revealing the physical laws of the universe, how our universe runs, you might ask, are we revealing physical laws or are we revealing the source code of the universe?

Are we revealing the way the universe is calculated? Something I've often wondered is, you know, where are these calculations done? Like if I do an experiment in my laboratory and I shoot one particle at another particle, I can calculate what's going to happen. But how does the universe decide what's going to happen? Is there a calculation being done somewhere? Is the universe basically like a computer that is doing these calculations? You can even imagine, for example, using the universe's physical laws to effectively do calculations that we don't have complex enough computers to do.

Anyway, back to the question from Rodrigo and Pedro, they notice a couple of things about our universe, namely the fact that we have a speed limit at the speed of light, and the fact that the universe seems to be quantized, that it's like broken up into chunks. And they wonder, are these clues that we are living in a simulation? So first, let's argue for yes, and then I'll tell you why I think the answer is probably no. The argument for yes, why these might be clues that we would be living in a simulation, is that they are the kinds of things we might encode into a simulation we wrote. For example, if you limit the speed that information can move through your universe,

it makes it a lot easier to program your universe because you can separate it into pieces. If you know that nothing that happens in this left corner of the universe can possibly influence the top right corner of the universe within a certain amount of time, then you don't have to do those calculations. Often when we do really big, complex simulations, that's the kind of thing we're doing is we're looking for shortcuts. calculations we don't really need to do. For example, in principle, you are affected by the electric fields from electrons in the

endromeda galaxy because the extent of the electromagnetic field is infinite. But in practice, that makes no difference to you or what happens to you or changes your life at all. So if you were doing the calculation, you could just set that to zero rather than actually calculating it and get the same answer. So we make lots of approximations and it would be very convenient to have a limit. on how fast information you could move. Because if there wasn't a limit,

if information could move at the speed of light, if you could shoot a death gun in one galaxy and instantaneously kill someone on the other side of the universe, then every time you're doing an update to the universe to step it forwards in time to figure out what happens next, you need to scan through the whole universe and see, is somebody going to shoot a death ray? Whereas if you have a limit on the speed of information,

you only need to search within a certain space to see what's going to happen that's going to affect this person. or this alien or this rock. So it would be very convenient. In a similar vein, quantizing the universe, saying there isn't an infinitely small particle or a space can't be divided into infinitely small pieces would be very convenient because it would mean there's a minimum distance that you need to analyze in your simulation. When we do a simulation here in real science, for example, we usually create a granulated

description of what's going on, and we don't simulate things smaller than that. And how small we go depends on the problem we're solved. If, for example, you are trying to simulate a hurricane, you might not simulate anything smaller than a water drop. You don't really care what's going on inside the water drop. The water drop itself is your basic unit. If you're stimulating galaxies, you probably don't go smaller than an individual star. You don't really care about what's going on inside that star or even on the planets around it because they have no influence on how the galaxy is formed. So having a minimum unit to your universe is very convenient for doing those calculations.

So Rodrigo and Pedro are suggesting, hey, are these clues that the people who wrote our simulation have taken some shortcuts? Does this make the simulation hypothesis more likely? And I would say the answer is no, because we don't know anything about the meta universe. Remember that when we write a simulation of another universe, we can make up whatever rules we like. Sure, one popular thing to do is to simulate our own universe to probe it. But you can also create any crazy kind of universe with any physical laws you want. there is literally no limit. And what that means in principle is that by studying the physical laws of our universe,

you gain no insight, at exactly zero clue, about the physical laws of the universe on the outside, the real universe that's running our simulation. And that means we don't know anything about computers in that universe, and we have no idea what's hard or what's easy for those computers. Everything I've just laid out is basically assuming we have simple classical computer. just like ours. But if they have a very different universe, the whole concept of a computer could be very different. And what's easy and what's hard in those computers could be totally different. And so if you want to be really strict about it, I would say we can't learn anything

about the nature of that universe from examining our own. You might wonder, well, hold on a second. Don't we have a quantized universe? Doesn't that limit the kind of things we can calculate? Doesn't the fact that our universe is quantized limit the kinds of things we can simulate, forcing us to only simulate quantized universes. Doesn't that mean if we are quantized in probably the meta universe that's simulating us is also quantized? Not exactly. It's possible using quantized computers to simulate non-quantized universes. You can, for example, on a quantized computer, write down the equation of a perfect circle, a continuous circle, which is not quantized. The equation for that is pretty simple, right? It's x squared plus y squared equals some number. And that's a representation.

computers in the end are representation. Yes, they're moving information around. But what that information means depends on the context. You know that that information represents stars in a galaxy or drops of water in a hurricane, but somebody else just looking at the bits doesn't necessarily know what it means. So the power of the simulation depends on the interpretation of it, of knowing what that information represents. And so it can represent almost anything. You're going to arrange bits to describe a classical unquantized universe, even if you are making a computer that is quantized. So unfortunately,

I don't think that we can learn really anything about the nature of the meta universe or if it exists by studying the nature of the physical laws in our universe. But super fun question. Thanks very much for thinking about that. And hey, if you disagree with me, write me an anger email to questions at danielanhorpe.com.

I will pass it on to the programmers of our universe. I got one more really fun question. So stick around. just after this 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 expectation. 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 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. 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 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 vibras 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 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 IHartRadio app, Apple Podcasts, or wherever you get your podcast. A foot washed up a shoe with some bones in it. They had no idea who it was. Most everything was burned up pretty good from the fire that not a whole lot was salvageable. These are the coldest of cold cases, but everything is about to change. Every case that is a cold case that has DNA.

Right now in a backlog will be a cold case. identified in our lifetime. A small lab in Texas is cracking the code on DNA. Using new scientific tools, they're finding clues in evidence so tiny you might just miss it. He never thought he was going to get caught

and I just looked at my computer screen. I was just like, ah, gotcha. On America's Crime Lab we'll learn about victims and survivors and you'll meet the team behind the scenes at Othrum, the Houston lab that takes on the most hopeless cases to finally solve the unsolved.

Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. All right, we're back, and this is Daniel, and I'm answering questions from our awesome listeners who are really looking great these days. I love that new shirt you got, by the way. Thanks everyone for sending in your questions. Please don't be shy. I promise. it's fun, we'll be gentle. We are very friendly to our listeners. If you have a question, please, please, please write to us to questions and danielanhorpe.com. I love that little ding when I get a new email. Well, here's a question from the other side of the world from Andreas of Sweden. Hey guys. So I'm wondering if you had full control over space related funding for the next couple of decades or so, what would be your top three projects to focus on? What

would bring the most knowledge for the buck, so to say. For example, solar gravity lands, drilling into Europe's oceans, housing humans permanently on Mars, etc. I would love to hear your thoughts on which projects you would focus on. Thanks, Andreas, from Sweden. All right, Andreas, thank you very much for this question. You have unleashed my science fantasy budget. I would love to think about what it would be like to get to be in charge of the science budget or more than that to get to be in charge of how big the science budget is relative to other things. But I warn you, this is going to be depressing because when we're done, we're going to have to go back to reality where the science budget is a tiny little

slice of what governments spend their money on. And it's frustrating and depressing to me because I like to imagine this alternative universe where we do spend more money on science. Because it's easy. If you wanted to know more about the universe, it's very simple. You just got to spend more money. All the science agencies at every government around the world, when they put out a call for proposals, they get really, really clever ideas for very, very smart, hardworking people, and they have to say no to most of them. If you're at the National Science Foundation, people send you crazy ideas they've been working on for free, four years, about ways we could learn incredible deep secrets about the universe and mostly you got to say no to almost every single

one of them why don't we just say yes to more of them we are literally in the candy shop of the universe we have pockets bulging with money and we are just spending pennies it's incredible to me what we could learn the alternative history of the world if we had spent more money on science for the last 50 years what we could already know what deep secrets about the universe we are clueless to just because we spent money on warships instead, it drives me crazy. So thank you, Andreas, for letting me spend a moment thinking about what do we like to live in that alternative universe where scientists, or at least me, got to decide what we were spending our money on.

So I like the projects that you suggested, solar gravity lens, Europa's oceans, humans on Mars, those are fun, but I think top of my list, if I got to decide what we spent money on would be a massive program to build more space telescopes. These telescopes sit in Earth's orbit or nearby and just gather information about the universe. We talked earlier in the podcast about how much information there is. And we are capturing just a tiny slice of it. Like we have looked out into the universe, but we have not seen very far because seeing far requires looking for a while. Like things that are very far away in the universe are distant and that means they are not very bright. And so their photons are rare.

Like at the source, they are pumping out a bunch of photons. They could be very, very bright where they are. But those photons drop in intensity as they get further from the source. Like, there's no change in the number of photons. But the number of photons per area, per square meter, for example, drops as you get further and further away. So that by the time you're 12 billion light years away from that galaxy, you may be getting one photon a minute or one photon an hour. And so to see it, you have to point your telescope at that spot in the sky for a while. That's why, for example, what's called the Hubble Deep Field is so astounding and so beautiful

because they just pointed the Hubble at one point in space for hours and collected all the light and they were able to see more distant galaxies than anybody has ever seen before. And what's going on out there in the distant universe in just like another direction of space that we haven't even looked at? We don't know because we don't have enough eyeballs to look everywhere at the same place. So I would spend so much money on so many more telescopes and point them in so many directions. You know that scientists have to compete for time on the Hubble and there are many, many great ideas, great uses for the Hubble and the other space telescopes that never come to be just because there isn't enough time on them.

And so there's all this information and it's hitting the Earth. These photons are coming here anyway. They're just not being seen. Nobody is gathering them. So that information literally going in the garbage. So I would spend a lot of money, hundreds of billions of dollars, if I could, to build a whole fleet of space telescopes just to look out at the sky and gather that information. Rather than just letting it hit a rock and get ignored,

there's so many secrets that by the universe we could learn if we just looked. So let's build some more eyeballs. So that's my number one is building a massive program of new space telescopes. Number two would be to explore our neighborhood. There's so much going on in our solar system that we do not understand. There are so many places in our solar system where there could be life like right now in the oceans of Europa and under so many frozen crusts of moons. We've never been to Uranus's moons, for example.

So the second plank of my personal science program would be a very aggressive robotic exploration of the solar system. Basically, I'm going to visit every planet. I want to have orbitors around every planet taking detailed pictures of its surface and measurements of its magnetic field and internal composition. And I want to land on every rocky surface in the solar system. No moon should go unexplored. One of those moons could very well have life living under the surface. So I want to land on Europa and drill into the core. I want to land on every single moon.

I want to land on Pluto. I want to take samples and bring them home. You know that the only samples we have that are not from Earth are from the moon or a few rocks that fell off of Mars and came to Earth. We don't even have on Earth any rocks from Mars yet. We do have an elaborate program of Mars sample return, which might bring us some rocks in the next 10 years. But I want rocks not just from Mars, but from Mercury, but from Venus, but from Pluto, but from every moon on the solar system. Imagine the science we could do if you could have samples from all those places and compare them and study them and look for microbes and understand the chemical composition. What a treasure trove of information.

We are just in the dark. We are making guesses about what's going on out there in the solar system and under those rocks because we just don't know. And the only thing that limits us from doing it is money. Like we know how to do this. It's not that it's easy. It's hard. It's technical. It's complicated.

But we can do it. I mean, you saw NASA, for example, fly a helicopter on Mars. They know how to do this stuff. And if they don't, they will figure it out. And the money spent on figuring it out will also reveal other things. We'll generate new technologies. So if the only obstacle to learning these deep secrets and having this much science fun is funding, I really don't get why we're not doing it.

All right. But you asked for my top three projects. Number three on my list would be a massive system of gravitational wave detection. This is a brand new way to look at the universe, and for a long time, it seemed like impossible. How could we possibly detect these super tiny little ripples in the fabric of space itself? When people were working on this in the late 90s, I was actually applying to graduate school and trying to decide where to go and what to study, and I was thinking about astronomy or astrophysics or particle physics, and I visited a program where they were doing

searches for gravitational waves, and I remember thinking, this is nuts. These folks are never going to see anything. it's impossible they could ever develop a system so sensitive that they could see these things. Well, I was wrong, and they won the Nobel Prize. So, congrats to them. It's wonderful. And what they've done is they've opened up a new way to look at the universe, not just with our eyeballs and with photons, but with gravitational waves. And we can see the universe in a different way using gravitational waves than we can with photons.

Because gravitational waves are not absorbed. They can pass through anything. I mean, they scatter and they can reflect, for example, if they have. hidden really dense objects, but they're very different from photons. And so they can tell us things that photons cannot. So it's like a whole new kind of eyeball, not just more eyeballs. And we have gravitational wave detectors, but they're kind of small and they're not as sensitive as they could be.

So there's this fantastical, hilarious, awesome, wonderful science fiction project called Lisa, which is essentially a gravitational wave detector in space. The idea is that you have these three satellites out there in space that keep a fixed relative distance to each other, and when a gravitational wave passes, it stretches space a little bit between them, and they can measure this because they're shooting lasers back and forth to measure the distance between these satellites. So it sounds ridiculous. It sounds crazy. It sounds expensive. All those things are true, but it's also possible. And it's something people are really working on. And again, the limitation really is just time and money. So I would

fund that as my number three. I'm in charge of the science budget program. And you might wonder like, wow, Daniel, that does sound expensive. Yeah, and it might be that I've just proposed a trillion dollars of spending on science. But you know what? Every dollar we spend on science is a dollar that goes to education. It goes to people who are working on these things. It reveals secrets about the universe and all that money is spent here on Earth. Like, you might wonder, why are we spending money, sending robots to the moons of Jupiter

instead of building more housing for the poor. Yes, we should build more housing for the poor and we should send robots to the moons of Uranus because that's an investment in ourselves. Every dollar we spend on these projects comes back to us because it creates more educated people, it creates more knowledge, it creates more love for the universe and it creates new technology.

If you believe in humanity and in our capacity to understand the universe and to explore it, then you should invest in science. that doesn't mean taking money away from other things. It means, frankly, borrowing money from the future. It means taking out loans to spend this money because it pays for itself. It absolutely does. Every time we invest in basic research, it transforms our economy in ways we cannot anticipate in ways we cannot expect. The only thing we can anticipate is that it will. So what is the next crazy discovery about the universe, which will transform the very nature of our lives and our economy and

make us all much richer so that we can all afford housing and food. We don't know. Of course, we don't know. It's exploration. But the only way to get there is to fund basic research. For those of you who are wondering why I didn't talk about humans on Mars, I think that's mostly ridiculous. I think terraforming Mars is a huge project, which would take much more than just money. We need to figure out how to get enough CO2 on the planet to keep it warm enough without poisoning humans. We need to generate oxygen, which will take microbes, of years. So I think that's not impossible, but it's not just a question of money. So my top three picks would be a massive space telescope program, aggressive robotic exploration of the solar

system, and new space-based gravitational wave detectors. So thank you so much, Andreas, for letting me think about that and letting me fantasize about an alternative universe where a scientist president gets to set the amount of science spending and decide what it gets spent on. Probably we'll never experience that in our universe, but we can continue to hope. Thank you, everybody, for sending in your questions and to those of you who are just passively listening, that's all right as well. Thank you for lending us your questions, your ideas, your curiosity about the nature of the universe. I hope that one day we all find answers to all of our questions. Thanks for listening. Tune in next time.

Thanks for listening and remember that Daniel and Jorge Explain the Universe is a production of IHeartRadio. For more podcasts from IHeartRadio, visit the IHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. 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 her gone. Hold up. Isn't that against school policy? That seems inappropriate. Maybe. Find out how it ends by listening to the OK-stores. Storytime Podcasts and the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.

Every case that is a cold case that has DNA. Right now in a backlog will be identified in our lifetime. On the new podcast, America's Crime Lab, every case has a story to tell. And the DNA holds the truth. He never thought he was going to get caught. And I just looked at my computer screen. I was just like, ah, gotcha. This technology is already solving so many cases.

Listen to America's Crime Lab on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. This is an IHeart podcast.