SIO383: Ask An Astrophysicist Anything!

Transcript

This transcript was generated automatically and may contain errors — the audio is the record.

0:00:18 Thomas: Only. This is episode 383, I'm your host Thomas Smith, and I'm so excited for today's episode. Space! Space, space, space, and other science. I put out the call recently for questions for astrophysicist Brian, Dr. Brian Gillis, and you folks came, came through on Patreon, by the way, patreon.com/seriouspod. You folks came through in spades. Lots of great questions, much so, in fact, that we recorded extra and there's a two-parter for you. So lots of questions and answers to the keys to the universe coming this week.

It's Learn Secrets to the Universe Week, because this is a two-parter. Want to thank the patrons again for their great questions, this was so much fun, so let's get on over to part one. And because it's a two-parter recorded in advance, if you'd like to hear part two, jump on patreon.com/seriouspod and I'll get it up right away so you can hear both, of course. As always, you get the ad-free show, you get the bonus stuff, uh, going to be Memento very soon, can't wait for that. Patreon.com slash seriespod, no so much to all our patrons for supporting, and here we go. We're joined by astrophysicist Dr. Brian Gillis, how you doing today, Brian?

0:01:25 Bryan: Doing well. How are you Thomas?

0:01:26 Thomas: Doing well, and I think you brought your space cat, we may hear from space cat time to time, that's okay

0:01:30 Bryan: Oh? Yeah, maybe even two space cats. We'll see

0:01:31 Thomas: Oh two space cats, we're a fan of space cats on this show. I'm so excited to do this, Brian, thanks for agreeing to do this. I put out the question thread on the Patreon, patreon.com/ serious bot of course, was where you could go if you wanted to find out, you know, the secrets to the universe and everything. But, you know, you missed out on this round, but I'm sure there'll be more secrets to universe, so make sure to sign up. And people have asked you some great questions, and I hear you're ready to tackle all comers. I can't wait.

0:01:33 Bryan: Yeah, let's just go through them and See what we have to say about each one

0:02:03 Thomas: All right. Well, David Bax, parentheses, Spino Breaker asks, what's your favorite dinosaur? What? You said anything. Anything. Any dinosaur thoughts?

0:02:03 Bryan: Yeah, I'll go with the chickadee. It's pretty cute You're It is a type of bird birds are dinosaurs You have your silly question you get your silly answer

0:02:16 Thomas: Chickadee. Ah, yeah. I don't, I look, Arlo is way into dinosaurs and I guess I don't, you know, I just, I'm a dinosaur lover in general. I like, I mean, there's always going to be a soft spot in my heart for Triceratops because it gored me through the heart. No, I'm just kidding. I think that like that TricERATOPES, you can't, it's hard to beat that for me like that's such a weird friggin animal like how did that exist it's so cool that's a good one all

0:02:47 Bryan: Yeah, yeah Yeah. Oh, well, cool ones that still exist. Just try to explain the duck -billed platypus and see if somebody believes you that that's a thing that actually exists.

0:03:00 Thomas: That thing is not real that's true a good point venomous

0:03:03 Bryan: Yeah, it's a mammal, but it lays eggs and it kind of looks like a bird, but and it's got these venomous claws and. And

0:03:12 Thomas: Claws I didn't know that part what this thing's getting weirder by the minute no

0:03:13 Bryan: Yeah, we'll have to look it up. I remember hearing that.

0:03:19 Thomas: I wasn't doubting you I'm saying this thing I bet it developed those it's like I got to get even even weirder does it have like goth makeup now too me neither at this rate all right Darren Bennett asks uh to know your thoughts on muon g2 and potential new physics there that's not something I'm aware of or the probably most of the audience so you may have to frame that for us a little hmm

0:03:26 Bryan: Yeah, I wouldn't be surprised.

0:03:39 Bryan: Yeah, yeah. That's actually more a particle physics thing than astrophysics. So it's kind of out of my wheelhouse, but it's basically, I think, a new super collider at Fermilab or something like that. I up a bit on it, since it's not really astrophysics. I don't have much familiarity on it. It seems to just be testing the standard model of particles. Not too familiar with it, but yes, more tests are good. Maybe we'll find something cool, but yeah, far outside of my experience. Particle accelerator yeah yeah one of those get things going at in ridiculous conditions very high high speeds um if they do something surprising or if everything behaves as expected please

0:03:44 Thomas: Oh so it's not a particle itself it's a particle accelerator okay gotcha Keeping this plate spinning asks, the Mayan calendar or any ancient calendar was done by observing the skies and understanding when seasons change. I was wondering if this ancient look to the heavens inspires the, the doctor to think, oh, you're the doctor now, too. Cool. To think this need to understand and learn is deep inside us, or if he finds it annoying because of astrology and mythology.

0:04:51 Bryan: Well, you, is a lot of pseudoscience built on, on ancient calendars, but there's also a lot of real science built on it, and a lot of what the Mayans did was their attempt at real science and figuring out things, and you know, it's not their fault when other people use their work for pseudoscience.

0:05:10 Thomas: I I know. I feel like if we got the Mayans here for an interview, they'd be like, what the fuck are you talking about? We didn't predict it.

0:05:17 Bryan: Yeah, like that whole thing where the long calendar, yeah, like remember in like 2012, the long count was supposedly coming to an end, which meant the end of the world, And I'm sure if a Mayan was here, they would just say, "No, that that's the time you just started over." It's like when December 31st ends you go to January 1st, you just go to the beginning of the next one. Yeah, but but yeah just look at it

0:05:19 Thomas: We just wanted to know when, like, my friend's wedding is and, like when the harvest, that's all. That's all that was. We wanted to schedule stuff. Yeah. Just turn over the calendar. Yeah. It's too bad we can't get an interview with them, you know it would be really fun if we were able, like, somehow, universal translator. First off, I don't speak Mayan, uh, I speak modern Mayan, not ancient Mayan, you know, that's not my specialty. No, and it would be really to try to tell them these things, then they'd just be like, what are you, what in the world

0:05:49 Bryan: Okay yeah yeah uh, so, um, they asked, um, does inspire me to understand. Do you think the need to understand and learn is deep inside us? And yeah, definitely. They were doing this before. And one of the things I really like about looking at these ancient experiments is it proves that there were always incredibly smart people in the world. They just didn't have the tools we did. And so they figured out very clever ways to use the tools they had to come up with things. And a lot of these ancient calendars are surprisingly accurate for all the advanced math they had to do. And it just amazes me. And it's also kind of spinning off from there, whenever you hear about the ancient aliens, that's really insensitive to the people who lived back then because it implicitly says, no, they couldn't have been smart, it had to have been aliens.

0:06:21 Thomas: Yeah

0:06:55 Bryan: And I say, no. Humans definitely were very smart back then. Then if you look at all they figured out, they didn't need alien help or whatever.

0:07:03 Thomas: I think about that a lot. I think that's a great point. It is, it is amazing to think about, like, how, you too, back then, like, the difference one brilliant person could have made. I feel like the less, I feel like the less we knew, kind of the more impact one person could have, you know. And it's interesting to think about, like, how many brilliant people might have lived, and who, who knows if, if it was recognized, who knows what they accomplished, but the things they did accomplish is like, geez, that is so, so amazing to try to to tease, tear apart, uh, this today's lens.

All right, Liam Appleby asks, you mentioned multiple time dimensions in the portal episode. How would that actually work? I've heard this concept in sci-fi, but I've always thought it was sort of nonsensical. If we imagine an ordinary, ordinary spacetime, and let's suppose it's fully deterministic, then if you ask me, what's the state of the universe at time t, I can answer that. But if you have two time dimensions, then I won't necessarily be able to answer that question. Well, I guess you'd have t1 and t2. No, you'd have, yeah, okay.

0:07:19 Bryan: Yeah. Yeah. Multiple I think at least that part is simple. You just have to provide two coordinates. It's like, like providing a location in physical space. We have three dimensions. So you need three coordinates.

0:07:58 Thomas: Yeah, right. Yeah. Okay, I'll continue the question, and then we'll see. Imagine R deterministic spacetime now has 2D time and contains a guy called Bob. Imagine that in some region of that space -time, it's raining. In some other region, Bob has opened his umbrella. Assume those two regions partially overlap. Now you ask me, is Bob wet or dry at time S or T inside of that overlapping region? Well, the answer depends on how Bob traveled through 2D time to get to S and T. If Bob went through the rain region first, he's wet. But if he went through the umbrella region first, he's dry. Oh, interesting. So the state of the universe on the path we take through space - time time, not just the time, st I can't unambiguously answer the question, what's the state of the universe at time S comma T. That's hard to visualize, so I drew a picture. Oh, shoot.

0:08:53 Bryan: So to kind of describe this picture, I'm changing a bit to make it easier to visualize. So imagine you're in a building that has four rooms in it. One on the bottom left, top left, top right, bottom right. And the rooms of this are described by the two different time dimensions. Left and right is one time dimension, up and down is the other. And so when you go up it starts raining, and when you go right, Bob takes out his umbrella.

So if you want to get from the bottom left to the top right room, you can take two paths. You can go up first then right, or right first then up. So if you go up first, it starts raining first and then Bob puts up his umbrella. If you go right first, Bob puts up his umbrella and then it starts.

And these leads to a contradiction in that you get to the same place, which should have the same state of the universe, but if you had taken one path, it started raining first and Bob got wet, and if you took the other one, Bob got his umbrella out first and didn't get wet. It. So the question is, what's going on here? And my response is, this is obviously a paradox in that you get a contradiction here.

So the way I interpret this is that this description of how multiple time dimensions could work results in contradictions. So this wouldn't be the way it would actually end up working if we did have more than one time dimensions. There would have to be, you know, some other rule going into it. Like the way I mentioned multiple time dimensions before is with the time travel to the past.

And if you do it like that, basically the way it works with the multiple dimensions is we have our own normal dimension dimension and then a dimension for change, our just everything as normal. And then we add a new time variable, which works differently from the first one. Like let's say it starts at zero, and then every time somebody goes back in time, the new change timeline is incremented by one.

So you go back in time, you add one, you go back in again, it's now at two. And so in this, there's really only one path you can take to a different place. It gets a bit more complicated if multiple people are going back in time, but you could say that you somebody goes back, you take however many timelines are existing, add one to that. There are ways to make it work so that you never get collisions along this dimension and don't get paradoxes.

But yes, as Liam says, the way he's describing it, that would be a paradox. And so you get a self -contradictory universe. So you have to think of a different way multiple dimensions could work, and there are ways it can, they might not be how it would actually turn out. It might be that there's some reason we haven't thought of, you could never have more than one time dimension. It's something that's hard to test, honestly, we don't

0:12:07 Thomas: No.

0:12:07 Bryan: Exactly have That Many time dimensions to play around with, uh.

0:12:07 Thomas: Kidding. Yeah. I don't think I fully thought that through at the time. Why, why did we need another one to kind of, uh, uh, was it Just if If Well But What about time travel where you don't, where nothing changes, would then, would you, okay.

0:12:16 Bryan: Do Allow Time Travel basically. Yeah. Time travel is change things. If you don't change anything, you can travel to the past without a new dimension. Yeah.

0:12:30 Thomas: Okay, so that's right, so yeah. Think initially I was translating that into like, oh, now we're at multiple like timelines, as in like, like, almost you, like you've split to another person, kind of like the the Copenhagen whatever interpretation doesn't.

0:12:31 Bryan: Yeah.

0:12:41 Bryan: That is Kind of what's Going on, you just have copies of it in different timelines, each labeled something in this new dimension, uh, that we have, it's just like That

0:12:54 Thomas: Well, doesn't that solve it? I mean, if you if you split literally splitting, then I feel like there wouldn't be the contradiction because, yeah, one of you did the other thing and one of you did this thing and that's fine.

0:13:00 Bryan: Yeah Yeah, right, that, that's how it could work, is that if instead of the way time working, like with two smooth time dimensions, as Liam described, you have splitting into new timelines, and the split occurs in the second dimension, then it does work. But we do have to accept that the two dimensions don't work the same as each other. And if you want multiple that do work the same, I haven't really thought through how, how that might work. I'm not even sure it would be possible.

0:13:33 Thomas: Hmm.

0:13:34 Bryan: It might always cause paradoxes, but yeah, the universe basically needs to be set up to allow time travel that changes the past. Kind of the point I was making in that episode is, yeah, yeah.

0:13:43 Thomas: Yeah. Yeah. Yeah. I was just trying to refresh myself on it. That's all. Yeah. If you had another time dimension, like would the overlap part even make sense necessarily?

0:13:52 Bryan: The dimension separates them and it's basically putting the two in a different place. And while Well, I guess the overlapping region, yeah, that's, yeah.

0:14:01 Thomas: That would be like a split off. But if you just had an independent time dimension. Trying to think of it because like space, you don't really say, well, the X and the Y have like this overlap. Lap and then they separate. It's like, no, they're orthogonal or they're whatever. They're,

0:14:15 Bryan: Yeah I think the overlap Liam was referring to was just the final state. Like in my example, the upper right room where it's raining and Bob has his umbrella out. It's not the dimensions themselves overlapping.

0:14:28 Thomas: Hmm. Okay. Interesting. All right. Can all get really high and continue to think about that at a later date. All Lawyer Esquire asks, can two things ever be so far apart that there is no gravity between them? Also, is gravity actually a force or just the curvature of space time? I'm sure those are two very easy to answer quick questions that

0:14:48 Bryan: Yeah, first the one actually, yes. The force gravity travels at the speed of light. So if two things are far apart enough that the of light isn't long enough for whatever interval, imagine things pop into existence suddenly. And then before there's been enough time passed for light to go between the two, there won't be any gravity between. So short answer, yes, they can be that far. And in fact, if they're far enough on separate parts of the universe, they could be far enough, their gravity will never affect each other. So definite yes to that question. Uh,

0:14:55 Thomas: Yeah, mm -hmm, oh, so it's not just distance, because something could pop into existence, two things right now, and be, you a hundred thousand miles away, and they wouldn't, their gravity wouldn't have touched for, like, a second or two, or whatever it would be, but

0:15:30 Bryan: Yeah. So you think back to the gravitational waves, uh, we, uh, started detecting a few years ago. These were things that happened many years in the past and we're just noticing them now because the gravitational waves just got to us.

0:15:53 Thomas: So, Essentially, for if a thing X pops into existence, its gravitational influence sort of spheres out, like, like anything else, at the speed of light, and if something else exists within that kind of path, it, it is, its gravity is effect, I guess the only point, the only reason I said is stuff, if its stuff is super duper old, it could still be super duper far away, but its gravity has essentially effect made contact or whatever. Interesting.

0:15:53 Bryan: Yeah. Yeah. Yeah. Yeah.

0:16:18 Thomas: Okay, second part. Hmm.

0:16:19 Bryan: Part, is gravity a force or the curvature of spacetime? Well, it's not an either or. A lot of these things, it just depends on how you look at it. And you'd have to get down into a detailed definition of what exactly you mean by force. And from a general relativity perspective, gravity is not like the other forces and it's just the curvature OF spacetime. But from some models of quantum mechanics and quantum gravity, it is. And colloquially, with what we describe as a force, yes, gravity is a force. It really just comes down to definitions here.

0:17:00 Thomas: We'll say yes. The answer to the or question is yes. Bird Lawyer Esquire also asks, obviously, I like the obviously for this stuff. Obviously, electromagnetism and gravity are a big deal, and I know that the weak force comes into play when we talk about neutrinos and hypothesised WIMPs. Why does nobody ever talk about the strong force? Is it boring, solved, or both? Hear, hear, Bird Lawyer people, start sound off, hashtag talk about this strong force, what's going on here, Brian? Oh,

0:17:01 Bryan: Yeah.

0:17:31 Bryan: Well, the strong first is basically what holds protons and neutrons together. Each of those are made up of three quarks, either two up quarks and one down quark, or two down quarks and one up quark. And it's not so much that it's boring or solved, that it really only operates in this regime. It play a role in a lot of other subatomic particles existing. They're just ones that you really have to go out of your way in particle accelerators to create.

Not sure it's any more boring than other ones. To an all of electromagnetism, the weak nuclear and strong nuclear force are quote-unquote solved, and that there is a comprehensive model that explains them all and gives all the particles in the standard model of physics. The problem is that in astrophysics we observe dark matter, which can't be explained by anything we're aware of in the standard model. Everything seems to have an issue, so people keep coming up with ideas to extend the, the standard model.

And I guess you hear the other forces around there. Well, obviously, electromagnetism a lot. The weak force can have results which can cause other particles to go out on their own, like neutrinos. But the strong force doesn't really have an opening to explain dark matter, so there isn't much focus on it. Honestly, I, if dark matter is explained, it's not going to be in terms of these forces necessarily, but there may be some other force that's related to some new type of particle.

But really, it's just one of the big unanswered questions in modern physics is what exactly is dark matter, and I can't give you the answer to that today, we're working on it. Oh,

0:19:34 Thomas: Yeah. Me and you, you mean? Yeah, we're working on it. After this recording, Brian and I, we actually, we have an appointment, Brian. We better, we better hurry. We're, we're going to be right on that. Right. The Shell That Echoes Only asks, are there any quantum effects that have to be considered when observing galactic scale systems? Oh, interesting.

0:19:37 Bryan: Okay. Yeah. Um, I would say, um, definitely, it all comes down to how we're observing them. The light that comes, as light is quantized into photons, and this has direct effects on how light is emitted from things, and the way light comes out of atoms depends very directly on quantum mechanics, what wavelengths you get, and this is why we have what you call specific emission curves, like

0:20:19 Thomas: For detecting planets where we see like what they're composed of because of how the light is changed.

0:20:23 Bryan: Yeah. Like different types of atoms have different energy levels and the electrons in them can only be in specific energy levels. And if they drop from one level to another, it'll emit light of a very specific wavelength. And this is a quintessentially quantum effect, that it's one leap between these levels causes the fact that we get very narrow bands of emission, just very specific wavelengths from this. And these emission lines, we call them, allows us to determine what chemicals there are in the light. So once we can use quantum mechanics to break up these spectra and get an idea of what composes these stars or planets out there. So quantum mechanics is actually very useful in observing these systems. Uh,

0:20:24 Thomas: Oh, cool.

0:21:15 Thomas: Yeah, yeah, but I guess the probably focus of the question is just this idea of quantum effects kind of canceling out at large scales, right? I imagine where the questioner is coming from, but I guess quantum mechanics, it is our world, so it's always affecting everything in a way. Yeah.

0:21:25 Bryan: Yeah. Yeah, it does, it does always affect us, but there are some ways in which the effects don't simply cancel out. And, fact, the reason quantum mechanics was discovered is because of observed properties of light in the macroscopic world that didn't match up what we thought it would. And you have to take into account the quantized nature at the small scale to explain what we experience at the large scale. You could look up ultraviolet catastrophe if you want to learn about the history on it. We don't need to go into all that here.

0:22:02 Bryan: Yeah, it was because it was, they'd solved all the physics except for this one thing. But once they started, started unraveling this one thing, that light wasn't behaving as expected, and all of quantum mechanics opened up, and they realized they weren't even halfway done with explaining physics.

0:22:01 Thomas: Catastrophe. Oh, man, oh, man, That'd be fun to cover sometime, you know, we could do episodes like that, Brian, where it's like, you explain something, like that, to us as a storyteller, that would be really cool. Or maybe is that, what do you think about that idea? Is Yeah that'd be fun. Okay. David Backs, Spino Breaker asks, thoughts on the The Alcubierre, I don't know, warp drive.

0:22:30 Bryan: Yeah. Yeah, we can do that.

0:22:42 Bryan: Yeah.

0:22:42 Thomas: What effect would it have on something like relativity, especially with two different ships, both moving at faster than light, but at different rates relative to where they left? Could that cause some kind of paradox, time shenanigans? What even is this? Is this a TV show or is this a real thing? What do we got going here?

0:22:58 Bryan: This is science fiction. It's basically an idea for how you would be able to break the speed of light. Let me see if I can think of a good way to explain. I think it's kind of similar to what they do in Star Trek. They have this magical material called dilithium, which puts puts the whole ship into a quote-unquote warp bubble, which changes the space around the ship to allow faster -than -light travel. And it's, yeah, impossible with what we know of physics. And kind of what David brings up is that, yes, any type of faster -then -light light travel can cause time paradox shenanigans. I think we went over this in one of our earlier episodes on special relativity, that basically any faster than light travel leads to time travel, and

0:23:52 Thomas: Yeah. Can I slow you down, though? How do you pronounce that word and what is this from? Is this a real proposed thing or is it in a TV show?

0:23:55 Bryan: I it's pronounced Alcabier, and was proposed in 94. So actually, Star Trek predates this. So Miguel Alcabier, named after the guy, proposed methods by creating a wave that would cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. So it is kind of like that Futurama joke, that the spaceship doesn't move itself, it moves the universe, and this kind of sounds like it's stretching the universe out ahead and pushing the universe behind itself, and

0:24:00 Thomas: Okay. Oh, yeah. What would that do? That seems harder than just going.

0:24:33 Bryan: It did it does seem hard but it, well it supposedly would allow faster than light travel. I think the problem is that it requires, um, with with negative mass, which, as far as we know, doesn't exist.

0:24:34 Thomas: It's harder to just, why don't you just drive like a car? That seems easier than this.

0:24:52 Thomas: Oh, let me ask you this, Brian. Do you think this would have been around that time somebody taking the fact that we learned, Because not that long before that, we learned about the expansion of the universe being accelerating and all that. Is that someone being like, wait, that cheats the speed of light. Because even though we were told nothing could ever travel faster than that, things are moving away from us at faster than the speed of light because the space itself is expanding. Is that somebody being like what if that, but for a spaceship?

0:25:17 Bryan: I think it's more likely they took what's going on in Star Trek and tried to see if they could find a formal physics way to explain what's going on there. I think that's closer to what this actually describes.

0:25:29 Thomas: Maybe. But Star Trek goes a while back. I don't know. There's a lot of Star Trek for that to come out in 96. When discover that expansion of thing? Thing. Wasn't it like, like early nineties or was that before that?

0:25:37 Bryan: Oh, Oh, let Yeah, it was in the 90s that we got good evidence for it, actually, a bit after yeah for the acceleration I think it was the mid to late 90s that we got. So the, the dates are close, but the acceleration of the expansion of the universe came a bit after this warp drive was proposed.

0:25:45 Thomas: The acceleration of the, Oh, sorry. Do you want, that's what I thought.

0:25:57 Thomas: Oh really? Oh, okay. All right. Well, there you go. Question. Uh, basically speed than the speed of life, you're always going to get shenanigans, right? I mean, there's no, no, there's no not shenanigans short of the space trick with the expansion sport, short of the cheating where you're not actually moving faster than the speed of light relative to space.

0:25:58 Bryan: Yeah, Yeah.

0:26:18 Bryan: There is one way to avoid shenanigans. It's just that you have to break another assumption of physics. It's basically, uh, has the assumption baked in that there's no preferred frame of reference, which is to say the physics is equal for everyone. But if you break that, then you can have faster-than-light travel that doesn't allow time travel from some perspective.

So, for instance, if there were one superior frame of preference, that would allow you to have one firm, definite definition of time, time, and from that perspective you would never be able to time travel in that superior frame of reference, but you could in other reference frames. But there would still never be able to have any time travel that changes the past, as this one reference would always prevent time travel in it, um, you know, that's possible.

It's a way you could, and you know, in the real universe, there, there is arguably one kind of default frame of reference, we call the Hubble flow, which is basically the average motion of everything in the universe. So maybe you could set something up so that you can move faster than the speed of light relative to the Hubble slow, but you can never move back in time relative to the Hubble low.

0:27:41 Thomas: I've never, I've ever heard of that particular thing. Okay, Haddari, and thank you for the on pronouncing your name. Really appreciate that. Asks, talking about portals and dimensions, talking about portables and dimensions. Any thoughts on UAPs? Here we go. Here it is, Brian. I can't believe it took us this long. UAPS and the data collected from encounters like the 2004 USS Nimitz incident, the Tic Tac UFO. I'm not a UFO alien enthusiast. I just like a scientific explanation when there's verified anomalous data collected reflecting objects that appear to move in ways beyond our understanding. I really think this is a full episode at some point that I would love to do.

0:28:22 Bryan: Yeah.

0:28:22 Thomas: And Brian, I actually meant to ask you to do this, but you've been, you've been busy. I haven't wanted to bother you, but sometime I would love to do it. Here's the episode I want to do, Brian. Don't want to get into the, you gritty of like, well, you see here, this camera, it's actually an object that's in the foreground and not the the back or whatever, and all that stuff where it's like, I think it's always going to be some crap like that, but maybe, maybe not. It's not good for an audio medium anyway. That's You for the YouTubers to break down specific, you know, and why they may not be anomalous, whatever. I would love, I would like to do UAP. I'd love to talk about a, why this isn't aliens. Most, Most, most, most likely, high percentage, not aliens, like the constraints of the universe and go into more detail on why it would be very, very, very hard to believe that aliens were here and among us and making contact and all that.

But also like, I would be curious to ask you, Brian, and this will be, I think this is gonna be all teasers, but you can, you know, take on as much as you want now in a short question form. Let's say hypothetically, it is aliens. Let's just say tomorrow, somehow we find out, oh shit, it IS aliens. I want some, or some scientists, if you tell me there's a different kind of scientist that would be good at this, I want to know, okay, what happened?

Like, you get the news tomorrow, Brian, there's aliens. You're instantly got to be like, how the fuck are there aliens? What's the most plausible way that aliens could be here? And wouldbe a fun episode, too, to do that kind of thing. But I don't want to spoil it all here. Go ahead. Take on whatever you

0:28:49 Bryan: UAP.

0:29:43 Thomas: Think.

0:29:43 Bryan: So Let's not spoil that. So, Rana, put most of that off into a future episode. I think what I'll say now is one of the things we have to accept in life is we're not going to get an explanation for everything. Whatever happened is in the past. We can't go back and do an experiment to recreate what happened there. And this a way, it's more history than science.

0:30:06 Thomas: Hmm.

0:30:06 Bryan: We're not trying to solve a law of physics where we can set up an experiment or look for a new observation. This is something that happened once, and we can't go back and recreate it for the very problem that we don't know exactly what happened. Just something we have to accept about history. For things like this, where you see a UFO or UAP or whatever you want to call it, there are almost always multiple scientifically plausible explanations. And, you Occam's Razor, it's usually, more plausible to be one of those than aliens.

0:30:41 Thomas: Yeah.

0:30:43 Bryan: Was an old SMBC comic a while back that I remember, basically two panels. First panel is a scientist talking to a journalist and says, is, well, either this is a small experimental error or everything we know about science is wrong. And then panel two, the journalist published a quote, everything we Know About Science is Wrong.

0:30:57 Thomas: Yeah. It's so classic. Everything. Yeah, that's so good.

0:31:04 Bryan: And that's basically what most of these UFOs are. It's some quirk, something that was up in the air we didn't identify, a weird atmospheric phenomenon, a weather balloon or a glitch in the radar, are or everything we know about science as we're off. Yeah.

0:31:21 Thomas: But the episode would be fun to go more into detail. I know it's obvious to you, but like going into more detail as to why everything we know would have to be wrong for that to be true. You know, within, obviously it's not 100%. Who knows, we could be wrong about something. But yeah, that that's going to be a fun topic. I anytime you have time for that one, let me know.

0:31:41 Bryan: Cool.

0:31:41 Thomas: I question. Crowley's most recently metamorphosed Best of Queen album. Interesting. Is a very broad question.

0:31:41 Bryan: Yeah.

0:32:04 Thomas: I love this question. That's a really cool trying to understand how science is done kind of question. Love it.

0:32:08 Bryan: Yeah. So stars are actually, um, considered to be one of astrophysics is biggest, biggest successes in that the star model is one of the best at predicting the varieties of stars we see in the universe. And very little of it is actually based on specifics of our stun. It's all stuff that's calculated from theory, and the theory works astoundingly well At predicting everything we see. You can model and imagine what we see go through the stages of, like, basically just going back to a previous episode where you defined a star. A star is essentially a big fusion engine in that fuses low-mass elements into higher ones. So in the main sequence, it's firstly hydrogen into helium. Then it's helium into a bunch of other higher ones, and then the next stage is carbon, then neon, then oxygen. It goes through a whole series of this which you can predict from theory, from our understanding of the elements and, um, of nuclear experiments setting off fusion bombs on earth to confirm we Can do this.

0:32:29 Thomas: Hmm. Oh, cool.

0:33:21 Thomas: I saw a movie about that.

0:33:22 Bryan: Yeah. Although actually that was A fission bomb. Not Fusion.

0:33:25 Thomas: Oh, Fish and Ball. Oh, sorry.

0:33:27 Bryan: That, yeah, fission is splitting apart the very high mass atoms. Fusion is cramming together the low ones. And basically what happens is kind of in the middle of the periodic table, like exactly where iron is, is the lowest energy state. So if you take smaller stuff, cram them together, you get energy out. You take stuff more than iron, split it apart, you get energy out. But once you get to iron, there's nothing you can do with it. That's, you can't get energy out of it. You have to add energy to split up iron or add anything to it. Um, basically almost all that we know about stars comes from theory and looking at the vast array of stars we see around the galaxy. And I understand, there isn't much that relates specifically to the sun. It allow us a lot of looks at the smaller scale things. It's basically the only star that we can look at the real small scale things like the weather that's happening.

0:34:25 Thomas: Oh, yeah.

0:34:25 Bryan: And And, you know, we can make some predictions about what goes on in stars, the kind of weather or weatherish systems that happen and see, do we see something like that happening in our sun? But, you Know, if we predict something will happen only in red hypergiants, we cannot exactly test our sun for that. We have to see if we can get maybe a faint glimmer from the ones we can see. Like take a look at Betelgeuse, see if we can look closely enough, or just leave it as, okay, that's what theory shows, but we don't know for sure. But as theories go, the star model is one of the best we have in astrophysics.

0:35:05 Thomas: That's so cool. Hey, how hard is it to directly observe our sun? Like, I mean, this might sound stupid, but it's really fucking bright. Does it take a whole bunch of like, you lensing, whatever, to be able to like actually look directly in it in a way that, you you know, won't look like Trump just staring into the sun and covering his eyes slightly.

0:35:25 Bryan: Well, yes, you do have to use a lot of filters, but in observation, we use filters all the time. We want to limit what light we look at. And so it's just, yeah, for looking at the sun, because it's so bright, you have specific filters for it. But there are specific filters für a lot of other things. And you do have to control it a bit more because you're going to get a lot von stray light from it reflected. Particularly if you're observing from Earth, it's very hard because of all the refraction in the atmosphere. I mean, looking at die Sonne from Earth I'd say is pretty much a lost cause if you want to get any detail. I think you pretty much have to be in space if you want a good idea of what's going on there.

0:36:05 Thomas: Interesting. Yeah. And it's like we had telescopes for, I don't know, centuries. And we're like, well, we can't really point it there. That would hurt. That's a no -go, you know? Like, it must have taken a while to get the technology.

0:36:20 Bryan: Yeah, well, you can look at it, but only once.

0:36:23 Thomas: Well, twice. You got two eyes. The other thing is, oh, I remember, the history of science is the most fascinating saying thing to me personally, like it's, it's so much fun looking back at the things we've learned and how we've earned them. And I remember, um, hard because it's been a while, I don't remember specifically what this is, but I, you think about it, it makes logical sense that before we unlocked, you know, the power of the atom, like, like an Oppenheimer and all that stuff, I must have been really hard to figure out what the fuck was happening with the sun. Like, I remember seeing people people in olden times were like trying to calculate well much wood would would have to be on that thing for that fire to burn that much. You know, it's like,

0:36:26 Bryan: Okay, yeah, true, true. Yeah, oh, yeah. Yeah that's

0:37:00 Thomas: This isn't, yeah.

0:37:01 Bryan: A good point.

0:37:01 Thomas: It's like that. What, what is this? How is it burning forever? You know? I don't really blame people centuries ago for believing in supernatural stuff. Cause it's like, what the fuck is the shiny thing that gives us everything we need?

0:37:11 Bryan: Yeah, so much of this is very weird. Like, the Sun, from, you know, up until maybe a hundred years ago, when Einstein came up with this theory of relativity, I think that was about the earliest where you could have a good idea of what the sun actually was. And yeah, that's just a thin sliver of human history. And then before that, you know, the sun is seen as a god in so many religions.

0:37:14 Thomas: Yeah. Wow. Crazy.

0:37:39 Bryan: And, yeah, that's the one, if you're going to say something is a god, saying the sun is a God, okay, yeah. That makes sense. A lot more than what Christianity is going on about.

0:37:38 Thomas: Yeah. I, it, it might as well be, I don'T really blame people for that.

0:37:50 Thomas: Yeah. Yeah, yeah.

0:37:51 Bryan: Because, yeah you can see the sun. It's responsible for basically all life on earth. Yeah, okay. I'll give you that one.

0:37:58 Thomas: And it it didn't like send like a baby son to earth to then for us to nail that son to a cross for some reason. Didn't do any of that bullshit, but that would be kind of funny to imagine. Okay. That's so interesting. Man, there's so much. Again, Brian, I don't know if this is your, you don't have the time for all the episodes I would love to do with you, but I, I ,I don't know. Are there people who are kind of specialize in more of the, like the history of science? Is that a thing?

Or maybe, you know, like, cause those, those stories, If there are any of you like that listening, let me know, or you know anybody, because those kind of stories, I will, I am a sucker for those. If anyone is like, "Hey, I want to hear about how we invented this or how we discovered this," or yes, I always want to hear that. So, uh, just throwing that out there for anybody, or, or Brian, if you have time for any of the things that you know, but we already have a lot of plans for the limited time that you do have, I'm sure. All

0:38:05 Bryan: No, no.

0:38:24 Bryan: I'm sure there are.

0:38:49 Bryan: Yeah.

0:38:50 Thomas: Right, uh, David Backs, and I love the enthusiasm. Another David Back Spino Breaker question. Have you read anything about dark stars, dark matter stars of the early universe? And if so, what are your thoughts on their insanity? Tipping their hand a little bit.

0:38:50 Bryan: Yeah yeah.

0:39:06 Bryan: This is something that I had to read up on. It's kind of a outside my expertise. But essentially what a dark star is, it's if dark matter is one of some types of particles, then it's possible that if you compress dark matter enough, The different dark matter particles will mutually annihilate each other. Like, this is something that we can do in labs, like particle accelerators, if we create positrons, which are what's called the antimatter counterpart to electrons. So, like, an electron has a negative charge, positron has a positive charge, and it's kind of the universe's opposite of an electron. And if the two ever meet, it's a big explosion, a burst of light. They cancel out everything about each other except the energy, and the energy goes into photons and explodes. And so if perhaps dark matter is something that can do this, then theoretically, if it gets compressed enough, it can start a star-like reaction and create a annihilation star spewing out light, which is, yeah, very cool. Um,

0:39:22 Thomas: Yeah.

0:40:21 Thomas: It would still spew out light. That's so cool. That's fascinating. So a dark matter star. And is this the same? I know you mentioned it in one of our episodes, the possibility, I think it was of a dark dark matter, black hole, or am I remembering that right? Is that the same?

0:40:23 Bryan: Uh, Yeah, that well, it's the same in a sense that what happens if the dark matter is compressed enough, And a black hole is uh, outcome if it doesn't annihilate itself, but if the type that can annihilate self, then you'll get a dark star first. It's like with regular matter's black hole. If it's in the case where it can start up a fusion engine, it'll turn into a star before you can compress it. And then once it turns into an engine, starts emitting energy, that energy causes an outward pressure, just the ongoing explosion wants to expand, that prevents it from collapsing anymore. So maybe what happens with dark matter is when you start to compress it, at some point it ignites into a dark star, or maybe it doesn't and it just compresses until you get a dark black hole.

0:40:42 Thomas: Yeah. Yeah.

0:41:29 Thomas: So you wouldn't have the, like, maybe I don't know what, but I thought, do, do black holes not occur from a star first? Like it's a star and then something happens, it collapses, all that nonsense.

0:41:39 Bryan: Yeah, yeah, that is the normal way a black hole happens.

0:41:43 Thomas: Dark, could that happen with the dark matter one?

0:41:46 Bryan: Well, really With the way things are evolving in the universe, the, with dark matter is that it's dark, which is it doesn't interact with light, which means it doesn't have any way to give up the energy it already has. So, like, imagine a cloud of dark matter particles in space. Each of them has some amount of energy bouncing by. Like, you've got a bowl that represents a gravitational well and marbles in it representing the dark matter articles.

Now, you put a marble rolling in the bowl, it's going to roll back and forth or around, compound, and in the real world it loses energy to friction, but dark matter particles don't have that option, they just keep that energy, so they never end up compressing more because they don't have any way to get rid of their energy. And as the universe expands, it only gets worse for that, they slowly get spread out more and more as some particles by chance get escape velocity.

Actually, actually, maybe, so I'm just thinking this through. Some particles by chance are going to get escape velocity, but since energy is conserved, the ones in the interior are going to have less energy overall. So I think what will happen is eventually the halo will evaporate. You will get a cooler halo left behind,

0:41:46 Thomas: Hmm.

0:43:09 Thomas: This is the halo after what, an explosion or something? What, what halo is this, oh?

0:43:13 Bryan: Not so much an explosion. It's just that, you imagine you have a bowl and a bunch of marbles rolling around in it, colliding with each other. Every once in a while, in all of these collisions, one of the marbles will happen to get a lot of energy and go shooting so far it falls out the side of the bowl. And this will happen over time, but it isn't really an explosion. It's a slow process of things falling out over time. And And this will happen to dark matter halos as the universe expands. The halos will slowly evaporate and smooth out until there's really nothing left that can be identified as a halo.

0:43:33 Thomas: Right. I Think I'm still in the mode of the the star going supernova and then eventually somehow collapsing into a black hole, I don't know, does that happen, or Am I, do I Imagine that

0:44:01 Bryan: Yeah, so the supernova is kind of a different thing that can happen with matters because regular matter can give up its energy into light. Like all the things that happen in fusing a star are ways to give off light and get rid of its energy. So as that happens, the particles cool down and can collapse more. So when they have less energy, they aren't moving around as much. They don't puff up out of pressure and they cool down. And eventually it can cool to the point where it can collapse into a black hole. But dark matter doesn't have the option of cooling down. So it just slowly evaporates.

0:44:42 Thomas: Right, and I remember one part of the phase of the star, you know, whatever, and I'm sorry I'm so non-specific because I don't remember all the details, but one part that does involve the light itself acting on it, like as keeping it, what, apart or together, and that wouldn't happen because the the light doesn't interact with The Dark. Yeah, right, right.

0:45:00 Bryan: Yeah, that's basically a lot of the early parts. The light within a star exerts pressure outwards to Keep it from collapsing on itself. Now, when it does go supernova, one thing that happens is it's an explosion throughout the star, and at some levels of it, it explodes inwards and causes the core to compress. So there are stages where it isn't just cooling down but actually being pushed down because of the explosion outside of it

0:45:31 Thomas: Cool. All right. Dark stars. There you go. Civilpoliticsradio.com Fridays at 7 p.m. Eastern on Valley Free Radio asks, know there's more to the universe than what we can observe, but what can we learn about whatever is farther than we can see? Are there any technologies we might someday develop that would allow us to expand what we could observe, like gravitational wave detectors? Vectors. Also, are there any deductions we can make about the minimum size of how much more there is? I assume we can't know if there's a maximum size. Well, that's interesting though, because isn't it like when we look out, when we Look, Look and Look and look super far, we're looking back in time and we're Looking to when things were smaller, right? Isn't it like we can kind of see, is it the case that we can see everything that way?

0:46:15 Thomas: Or is there still still Like it's unknown If they're, yeah

0:46:15 Bryan: No, Not Entirely Yeah, I going on is, is that if you think, like, just imagine a static universe that wasn't expanding. So the speed of light is finite, so the age of the universe is, is 13, 14 billion years, depending on who you believe.

So the furthest you can look out in distance in this imaginary static universe is going to be 14 billion light years, the light year, the distance light travels in one year, because that's the maximum distance where if something emitted light that long ago, it would just now be reaching us. Anything further out than that, the light from it wouldn't yet reach us, but might in the future.

The fact that the universe is expanding actually makes it more difficult to see things, as it turns out, that if we're far enough apart from something else, the relative expansion of the space between us becomes greater than the speed of light. And so stuff emitted from points far enough away would never reach us because the space between us expands faster than the light can travel across it. So we end up with a limit to how far we can see back. That make sense to you?

0:47:39 Thomas: When, but we look back, I thought we can go so far as it's like 300,000 years of age of the universe until it becomes like it was like a fuzz that we can't see through, what am I thinking Of but Isn't it true that then we're kind of seeing everything then, right, it's just we can't, you know, because if, if it was that small Good

0:47:49 Bryan: Yeah, yeah, we're seeing everything that's close enough that light from it could get to us by now, but there are things farther away where, you know, they emitted light back then, but they're so far away that the light takes more time to reach us than the age of the universe.

0:47:57 Thomas: Yeah Oh Here's where I think I'm going wrong, so I think of the Big Bang is like everything was the size of, well, what do we think everything was, possibly the size of, it's absurdly small, right?

0:48:25 Bryan: That's the thing. We don't, astrophysics doesn't make a statement on everything. And this is kind of what the question is getting at is we don't know how big that everything was. It might be infinite. It it might be finite. And if you astrophysicist to describe in physics jargon what the Big Bang was, they wouldn't even say the universe was smaller back then. They Would just say that back then, everything was closer together. And you're not quite saying the universe was smaller, but there's been a separation of everything since then, and we're not entirely sure that it all started out as a point with everything together, um, you know, there are some theories that, you know, before the Big Bang things were actually larger than it, it was just a universe that got crunched together to very, a very small size and then exploded back out, or it might have been created from that, um, there are models, um, it's again, this is like that history thing, we can't exactly go back and test the Big Bang in lab, yeah

0:48:25 Thomas: Ah Okay Oh Yeah Wow, yeah, I feel like I know less than when we started, but that's probably good because some of the things I Thought I knew were wrong, so that's that's good. That's interesting. I'm

0:49:37 Bryan: Yeah Question Is, what can we learn about whatever is farther than we can see? And the answer is not much. It's not exactly nothing, but it's close. So gravitational waves, as I mentioned in a previous question, gravitational waves also travel at the speed of light. So for the same reason we can't see light from things that are far enough away way. We also can't see gravitational waves. Now, there might be some small amount of inference we can do by how things at just the edge of what we can see.

0:50:17 Thomas: Yeah. That's what I was thinking. Yeah.

0:50:18 Bryan: Like, what I'm thinking of is, like, if we go to the limit of what we can see, and what we can see at that limit looks like half a star, we can make a reasonable guess that right on the other side is another half of a star. Things like that, it's a little bit past that limit that we can make inferences about, but yeah, it's it's like that, um, the rest of the question, um, minimum size of how much more there is, uh, I'm not sure we can put a minimum. I, yeah, the only bound we have is what we can see. And it would be very strange if the universe ended right after what we can see, we

0:50:31 Thomas: Sure. Yeah, hell

0:51:03 Bryan: Can't rule it out.

0:51:04 Thomas: Of a coincidence.

0:51:04 Bryan: Or maybe what's going on, which is a bit less weird, is if instead of the universe ending, it wraps around itself, like the surface of the earth wraps around itself. Maybe the universe does that in some higher dimension. And we seen anything like this, but if hypothetically we were to see, hey, look, that side of the universe looks exactly like the opposite side of the universe. In that hypothetical, we could say, okay, I think the universe wraps around at this scale. Now, we don't see this, and as far as we can look out, the two sides of the universe look completely different. So, it's at least as much as we we can see, yeah.

0:51:46 Thomas: That's too bad. That would be really fascinating. I never thought about that. Hey, that's that same star from over there. What the hell? Would answer a lot of questions though, right? That would like, well, shit, like what if one day that was discovered and you're you're like, well, crap, it's that, that imagine that would close, close the loop, so to speak, on a lot of issues, wouldn't you think?

0:51:49 Bryan: Yeah. Yeah, um, Yeah, that that would give us, uh, some firm grounding and a lot of things that trying to model the universe and Big Bang. It would be very interesting if that happened, and, you know, theoretically it could. As we go into the future, we can keep seeing back a bit further as light has had more time to travel. So maybe in billions of years, we'll notice that the new universe we're seeing looks the same on either side.

0:52:14 Thomas: Yeah.

0:52:31 Thomas: Wait, okay, sorry, this is me misunderstanding. I thought we were seeing less over time because of the expansion of the universe. That stuff was getting like harder to see.

0:52:40 Bryan: I don't think the expansion causes it to get further. Things in the present are getting further away. And yeah, things do get fainter over time as it expands. But the maximum limit of how can see things does increase with time. It's It's one of these things where two paradoxical things can both be true. It's we're looking out farther, but everything we see is getting fainter.

0:53:00 Thomas: Yeah, but okay. I'm just thinking about some, some talks I've heard. I thought it was the case that in, you know, whatever X number bazillion years, we eventually won't be able to see like much at all outside of our thingy because stuff is accelerating. Like the movement of the expansion of the universe is accelerating so much that if it's going faster than the speed of light, essentially, then aren't we, aren't we losing stuff that we would see?

0:53:30 Bryan: Yes, that happens too. It's when things get farther away, they get fainther, but that faintness doesn't go down to zero. We can theoretically see, like, get signals from things that are farther away. It'll just get fainter and fainther. And I think maybe there will be at a time in the universe when, you, I'm just trying to think, but things like the cosmic microwave background, which is basically everywhere, we'll keep seeing that, that it'll just keep getting fainter and fainther, lower and lower energy as time goes on, coming from further away. You know, maybe there'll be some point in the ridiculously distant future where we see the last photon of the cosmic microwave background that will ever reach us. But up until that point, the ones we're seeing will be coming from further and further away.

0:54:21 Thomas: Yeah. I'm not sure I understand, but I'll, uh, I'll think about that and spinning that in the old noodle. That's interesting. That's all for part one. Lots more really fun questions with Bryan to go in part two. Reminder, if you want to get that early, go to patreon.com/seriouspod. Otherwise, I'll see you on super late Thursday a.m for part two. We'll see ya then. Hello?