Listener Questions #20

25:03all right so next up we have a question from our discord channel and if you want to join us on discord and i really hope that you will you just go to our website at danielannkelly.org and you You can click the link to find our Discord group. And today's question is from PipDarkat. What are you going to do the day, Kelly, when somebody has a Discord handle that's not safe for podcasting? Oh, I will ask our amazing audio engineer, Matt Kesselman, to bleep it for me. No promises. I already have a plan. Hey there, Extraordinaries. it turns out that listener Pip Darkat from Discord wasn't able to get back to us in time for putting the audio together for this episode.

25:48So I'm going to go ahead and read her question from the Discord. Hi, Daniel and Kelly. I want to know more about... Sukunarcheum. I was reading a feed about how this organism is a missing link between life and not life. Would you consider this for an episode, Kelly? Well, Pip Darkat, indeed I would. Here's your answer. Hope you're doing well. All right, so tell me about this question, and how do we pronounce the name of this critter? Oh, come on, man. You know I don't know the answer to that. You know that I am notoriously bad at pronouncing all of these names. So I'm going to say it's Sucanarchaum.

26:31Nice. That sounds plausible. Because I said it fast. Yeah, that's why. That was the trick. And so let's see. I'll jump ahead to why it's named that. So in Japanese mythology, there is a deity who is small, and the name is Sukuna. Oh, sorry. The deity's full name is Sukuna Bikana. My apologies to all of Japanese culture. And so they took the first part of that deity's name, and because this critter is exceedingly small—in fact, we haven't even seen it with our eyes yet. We've only found its genome and sequenced it so far. They put that name in front. And then since it appears to be from the domain Archaea, they named it Sukuna Archaea.

27:17Very cool. Which rolls off the tongue whether it's correct or not. I like it. Archaea is really fascinating. Tell us a little bit about Archaea. I think a lot of people don't even know that it exists. What is Archaea and why is it so weird and different? Yeah, so it's incredible. And, you know, I actually wonder if you know more about this from Dinner Table Conversations with Katrina. So feel free to jump in. We do have the tree of life right in front of our dining room table. So Archaea does come up sometimes. Do you? Do you have like a painting of the tree of life in your kitchen? We have a big poster of it.

27:46Yeah. Oh, that's amazing. I need that. And you know what I learned in this episode is that you won't find viruses on that tree. Yeah, that's true. Which kind of makes sense, but also kind of makes me think of some evolutionary questions. But anyway, okay. Way back in our evolutionary history. So very close to the base of that tree. you ended up getting three different domains. So you ended up with three splits. And so you get archaea, bacteria, and eukaryota. Eukaryota have membrane-bound organelles. So we are eukaryotes. We have these membrane-bound organelles. We called them organitos in a past episode.

28:23And I thought that was cute. And I'll never forget. I think it's amazing that eukaryotes basically have like a little clump of ocean, right? Yeah. We think life started in the ocean and we came out of the ocean, but we brought with us basically the ocean. We're basically little walking bags of ocean. It's sort of incredible. It is amazing. Yeah. And so these three different domains differ in things like what makes up their cellular wall, how they structure their genes. For example, bacteria and archaea tend to have circular chromosomes and eukaryotes tend to have linear chromosomes. So eukaryotes are distinguished because they have a nucleus.

28:58how do you tell the difference between prokaryotes and archaea? Yeah, so prokaryote is a phrase that just refers to organisms that don't have membrane-bound organelles, as I understand it. And I think that because we've created this distinction, people often think that archaea and bacteria are closely related because they're both prokaryotes. But as I understand it, archaea, bacteria, and eukaryota are all pretty similarly distant. Like archaea aren't that much closer to bacteria than they would be to us. All right. I feel like you're trying to understand the difference between leptons and hadrons and mesons and stuff.

29:34So we have eukaryotes, which are on the side. Then we have prokaryotes. And within prokaryotes, we have bacteria and we have archaea. Is that right? I think so. I did not prepare that ahead of time. I'm trying to pull this out of Kelly intro bio brain, but I never had to teach intro bio, so it never solidified. So then why are archaea a thing? How are they different from bacteria? So they're different in that they have like different kinds of cell walls. They have a different way of initiating protein synthesis. I think they differ in the way that they translate and transcribe their chromosomes.

30:06So they differ in the way that they sort of read and turn into proteins, the information that's in their genetic sequences. And those are the notes that I have written down. And so tell us about viruses. Why are they not in the tree? Are they not alive? How do you define life? all this stuff. There's a number of different criteria depending on who you talk to. Some of them will have different definitions than others. But two important features that tend to pop up in a lot of the definitions is that in order to be alive, you need to be able to do some of your own metabolism, some of your own metabolic processes.

30:39So you need to be able to like convert stuff into energy that you can use. And you need to be able to replicate yourself. And so viruses, they don't have any metabolic machinery. They just inject themselves into a cell, and then they hijack the cell's machinery to create more virus particles that then burst out of the cell and go off and start that process again. And is there some, like, philosophical justification for this, or is this just an arbitrary dotted line that humans draw between a big continuum of biological activity? I think it might be—what do I think? Is this like planets and dwarf planets all over again?

31:15Yeah. So I was wondering that while I was working on this outline, and that's what kind of made me go to the tree of life. And I think part of why we can't really fit them on the tree of life is that they just sort of don't fit anywhere on there neatly. And I wonder if because we couldn't neatly fit them on there anywhere, we're like, all right, well, you don't do these other things that are important. And if you were doing those things, you'd have more genetic information and we could use that to help fit you into the tree of life because we could see like, you know, what the blueprints were and how that fit onto the tree.

31:46But you don't have that. And so I wonder if part of it is just like, well, we don't know where to put them on the tree of life. So we're just going to say they're not alive. And I bet a bunch of the people who come up. Problem solved. Problem solved. But I'm sure a lot of people who come up with these definitions are going to be like, that is a stupid answer. These are, it's very important to be able to like, you know, make your own energy and reproduce and they don't do it. So they are not as good as us in some way. All right. Well, if you have strong opinions about the definition of life and whether viruses are alive or not, write to us with a strongly worded email.

32:14We would love to hear from you. Yeah, no, I think it would be fun to have a battle about the different definitions of life. Not a battle, a conversation, a genial conversation. And I love when these mysteries have the context. I think it's really cool that when we look at planets, we also see other stuff that's almost a planet. It helps us understand where it sits in the bigger question. And I love that there are other great apes that are still around. I wish there were more species of humans that survived to today because it would tell us so much more about our evolution and our context. And so I think it's really cool that we have not just life and inert stuff.

32:47We have this like weird stuff on the boundary that helps us understand like what life means. So that's very cool. And so you might be wondering, why did we talk about what archaea are? And then why are we talking about if viruses are alive or not? And the answer is that this, there was a finding recently of a new species of archaea. Does Katrina pronounce it archaea or am I? Archaea, yeah. Yes, great. Okay. Because if Katrina does it, then I'm doing it right. So anyway, so there was a new species of archaea that was discovered. and it has a very small genome and doesn't seem to do a lot of metabolizing.

33:20And so there was this idea that went around the popular press that maybe this is like a transition between things that are alive and not alive because there's this critical feature of being alive that is missing from this species. Ooh, so more of the fuzzy context. More fuzzy context. So let me tell you a little bit more about this discovery. So they were looking in dinoflagellates, which are these single-celled eukaryotes. You find a lot of them in the ocean. They tend to have like these two flagellum, which are like long stringy things that they sort of move around to help them get from one place to another.

33:53And one of the things that's interesting about them is that they produce bioluminescence, which you can see in the ocean. Oh, pretty. Oh, my gosh. Once I jumped into the ocean when the bioluminescing organisms were in there, and there was this like amazing blue light that just kind of like, oh, it was one of the coolest experiences. Where was that? This was in Maine, in northern Maine. Wow. Yeah, I was at a science conference. It's pretty sweet being a scientist sometimes. So anyway, dinoflagellates, they do that, but the scientists were not interested in that. They were interested in the fact that the dinoflagellate that they were looking at was thought to have a symbiotic critter living inside of it.

34:29And so they were trying to understand that symbiosis and how this, it was a cyanobacteria, might be benefiting the dinoflagellate. And so they essentially opened up the dinoflagellate, sorry dude, and they sequenced the stuff that was inside. And when they sequenced the stuff that was inside, they found an additional circular DNA sequence that they weren't expecting to see. And they did a bunch of extra studies to look at it and try to convince themselves that they hadn't messed something up. Because what was surprising about it was that it was so stinking small. The circular DNA was so small that it was about 5 % the length of a genome you'd find in something like E.

35:07coli, so like very common bacteria. And again, they thought it was a mistake. But they kept sequencing it and then they assembled it. And when you assemble it, what you essentially do is you look at the genetic sequences and say, OK, do these sequences match up with anything we see anywhere else in the tree of life where we know what it does? So trying to get a handle on like what might these sequences do based on what we know happens in other organisms. It was about 230-ish kilobase pairs where kilo means like a thousand. Right, Daniel? Mm-hmm. Yeah, I always double check these things. So super tiny.

35:41And so once they convinced themselves that they weren't messing up something, they put it on the tree of life. And they were like, OK, this appears to be archaea. It looks like it's a whole different phylum of archaea that we haven't seen before. And then they went through and they looked at what was in the genome. And they're like, OK, based on what we know about other organisms, what do these genome components do? So let me back up and ask you a question just to make sure I understand. because my understanding is when you sequence something, you don't just like pull the whole DNA out of the nucleus and read the whole thing.

36:13You do this process where you basically like shred the cell, chop up the DNA into a bunch of short bits. You sequence all the short bits like shotgun sequencing and then you use computer programs to like sew it back together. And this is like Craig Venter's big innovation decades ago that made the human genome much faster. And so then you have this mystery sometimes of like, well, where do these pieces all go together? And I think what you're saying is that when they were putting the puzzle together, they realized, oh, we're solving two different puzzles here. This is not one big puzzle. It's like if you start working on a jigsaw puzzle and you notice like, oh, there's lots of weird blue pieces that don't fit into the puzzle, but they do fit with themselves over here in the corner.

36:50Is that what happened? Yeah, that's an incredible explanation, actually. And so they didn't just find two critters. They actually found more than two critters in there. And so they put multiple puzzles together and a lot of the other puzzles, they were like, okay, we've seen these puzzles before. But then when they found Sukuna Archaea, they were like, what the heck is this? And at first they didn't trust that it was anything. I see. But once they convinced themselves that it was real and they hadn't made some mistake through the part of the process, they discovered that it appears to be a whole new phylum of archaea.

37:22And then they went through and there are a bunch of public databases where people are like they collect genetic information and then they put it online. And when they started searching through that, they found a lot of other sequences that were looked kind of like this. And so they think that this is the first example in the phylum that's been described, but that there's probably a bunch of other stuff out there that we've sort of seen but not recognized yet. All right. And so what makes this one different from other archaea? What makes it have its own phylum and makes it, you know, whip through the popular press and get an article in science?

37:52So what was particularly exciting was that when they tried to figure out what the few genes that were there did, most of them were associated with replicating the organism. So it could do its own reproduction, but there were very few, if any, genes associated with metabolism. And so it looks like it's somewhere between alive and not alive. So I mentioned, you know, the definition of being alive, you've got to be able to do your own metabolism and your own reproduction. This doesn't seem to be doing its own metabolism. So it's probably a parasite of some sort, but it can do its own reproduction.

38:29So it can't do its own metabolism because even a parasite, like, you know, something inside of you that's drinking your blood, it's still metabolizing the blood and like feeding its own internal chemistry. So what does it mean to not be able to do your own metabolism? Does it mean that like you're just stealing directly the chemical products that store the energy? I think so. I don't actually understand how you could not – I mean I guess in the same way viruses don't metabolize things. They just hijack machinery. I suspect that's what's happening here. I see. Yeah, fascinating. Yeah. And so most of the paper is like scientific details.

39:02But at the very end, the authors say something to the effect of like, maybe this is like an intermediate step. And like this could tell us something about how organisms go down the path to becoming a virus. Maybe you lose a bunch of stuff as you go and you end up with these very like shortened genomes. And not everybody was convinced. It's like a company that's deciding, hey, we don't need to have our own HR department. Let's just outsource it to some startup or AI or something. And then they become parasites. Wow, that was a quick step to criticizing corporate culture, wasn't it? Yes, that's right.

39:42But that's fascinating to suggest that viruses used to be more fully alive and have sort of lost this capacity or optimized themselves so they realized they didn't need it. That's fascinating. Yeah, it's an interesting idea. I don't know if it's an idea that's been presented elsewhere. And this was just an example that really illustrated that that idea might have some legs. But, you know, not everyone was convinced. So I read this paper in Science that was summarizing. So I should also mention that the paper we're talking about, the results are on BioArchive. So they haven't gone through peer review yet, but they're publicly available.

40:14But people got immediately excited when it went on BioArchive and Science covered it. And Science did some interviews with other people, and they found a San Diego State University biologist whose name is Elizabeth Waters. She wasn't part of this study, but she does look at small archaeoparasites. And she said that maybe this is a virus in the making. She said, this is a bit of a jump. If true, amazing. So she's like a little skeptical. If it turns out, that would be super cool. but there are other organisms with very small genomes. I think this one is particularly small, but it's not necessarily the case that, you know, a small genomed organism is, you know, the missing link between becoming a virus.

40:58And this is an example, folks, of good journalism here because they went out and talked to somebody who wasn't invested in hyping this result and who knows the details and asked her, like, are you impressed by this? And she was like, you know, she's holding her fire a little bit. And that tells you, like, we're not all convinced that this is a big change, that, you know, everybody's now going to update the textbooks or something. But it is exciting and promising. Yeah, absolutely. And to me, this highlights, you know, so maybe this is a little bit of a self-defensive statement I'm about to make here.

41:30So, you know, you've said that when physics is doing well, it's doing more than just taxonomy. This is essentially just taxonomy. They found something new. They were like, well, let's look at this new thing. And maybe this is leading to a brand new understanding of life or not life, depending on what you call viruses, you know, and just how things work and understanding our world a little bit better. And so I would argue just taxonomy is really important. Thank you for this fascinating just taxonomy. And thank you to PipDarkat for this fantastic Discord question. Well, if I could comment, I think that this is a fantastic bit of science, but I think it's especially interesting because it's not just taxonomy, right?

42:12You're not just putting it there and saying, well, look, it's just there. You're thinking about the consequences. You're drawing analogies. You're asking philosophical questions about what it all means. So taxonomy is very valuable partially because it inspires this kind of deeper thinking and making these connections. So I would say taxonomy is step one in a really fascinating and valuable process. Right, but you can't get to step two without step one. But I'll give you that. Yes, agreed. Okay, I'll give you that.

42:50Hey, everyone. It's Cal Penn, host of Earsay, the Audible and iHeart Audiobook Club. This week on the podcast, I'm sitting down with divergent author Veronica Roth to talk about her sprawling new novel, Seek the Traitor's Son. It's a sci-fi fantasy epic about two protagonists on opposite sides of a war and a prophecy neither of them wanted. My first book was Divergent. And when that came out, like, because it was so popular, I think it attracted, like, mostly positivity, but the negativity I sucked in like a sponge. And I think it was, like, critiques of things I liked when I was, like, you know, I was 23 and I wrote this book and it had all my, like, dorky little cheesy or maybe unrealistic loves in it.

43:31And I started to feel a lot of shame about those things. And so for the rest of my career, I steered away from those little things that like make you feel pleasure when you read. But I also was like saying no to these parts of myself that I then was like, screw it. So that's this book. Listen to Earsay, the Audible and iHeart Audiobook Club on the iHeartRadio app or wherever you get your podcasts. Aging is real, and so are the benefits of new Vital Proteins Collagen Sparkling Water. Because around the age of 30, your body needs backup to keep your collagen up. So get your daily glow up, now in three fresh flavors.

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46:12Okay, we're back and we're answering questions from listeners. If you have a question about the universe, you've never really had satisfaction with the answer, please write to us. We would love to give it a shot. You can email us to questions at danielandkelly.org. You can join our Discord, and you can find the link to that on our website, danielandkelly.org. We really would love to hear from you. So many people write in, and we respond. And then they say, oh my gosh, I can't believe you actually wrote back. Well, we really do. You will hear from us. Your message will not just be ignored in the black hole of the internet.

46:42That's right. We can't wait to hear from you. All right. And so now we have a really fascinating physics question from John. Hi, Daniel and Kelly. My name is John Chai. My question is, what would happen if the speed of light suddenly changed? Like, let's say a giant cosmic switch were flipped and suddenly the speed of light got cut in half. Would it be completely catastrophic for all of existence or would it go largely unnoticed because even half of the speed of light is still really, really fast? Thanks a lot and thanks for the great show. Oh, this is fantastic. And I think this is another one of those, you know, questions where, so you're always encouraging us to take what we know and think, you know, if we tinkered with it a little bit, how would that, you know, break the universe?

47:23And essentially, like, understanding how tinkering with things would change things helps us understand if we really understand what's happening. Yeah. And I use the word understand a lot because I'm the most articulate person on the planet. But you understand where I'm going. Yeah, and this actually connects to our earlier conversation about the Fermi paradox. You know, another way to imagine what aliens might be like that would make them very alien is if they lived in a relativistic environment. You know, what if they evolved in a situation where they're very often going at eight tenths of the speed of light relative to each other or relative to their houses or something.

47:58And so they observe relativity in action as children and they develop an intuition for it. And to them, it makes perfect sense that moving clocks run slow and moving yardsticks look short and all this kind of stuff. You know, to them, the universe would be very different and their path of their science would be very different than ours. But here, John is asking a different question. Basically, he's imagining that he's at the control panel of the universe and he's got in front of him all these fundamental constants. Because there are these weird numbers in the universe that seem to control how physics works.

48:31You know, why is the weak force weak? Why is the strong force strong? Why is gravity so weak? Why is the universe this big and not that big? Why are galaxies this size and not bigger? How come stars get this size? There are all these numbers in physics, and some of them seem arbitrary. And so he's wondering, if he was at the control panel and he cut the speed of light from three times 10 to 8 meters per second down to half of that, what would change? How would the universe look different? Would we notice? And I think part of the motivation for this question is that the speed of light is so fast that it's essentially infinite.

49:05You don't take into account when you're walking down the hallway the fact that the light that's hitting your eyeballs is a little bit out of date and the person walking the other direction is not actually where they appear to be. They're slightly ahead of it because the light has taken some time to reach your eye. We treat it as instantaneous. So I think he's wondering what life would be like, what the universe would be like if it wasn't so instantaneous, if we sensed that delay, if the speed of light was slower and like maybe closer to the speed of sound. Can I guess? So I feel like because it's going so fast, day to day we wouldn't notice anything.

49:36But when we were looking out at like stars, we'd have to take into account the fact that what we're seeing was even farther back in the past. But how am I wrong? No, I think you're mostly right. But before we dig into all those consequences, I have to nerd out for a little bit about what it means to change the speed of light. I mean, I think if you're standing at the control panel of the universe, the speed of light is not one of those numbers, one of the knobs for determining the nature of physics. I think those knobs need to be dimensionless numbers, not things with like meters per second in them.

50:08And not just because meters and seconds are things humans invented, but because the dimensions make it connected to so many other constants. Like for example, you could change the speed of light without noticing anything. If you also, at the same time, accommodated other things, like you change the length of a meter and you change the speed of light, we wouldn't even notice. It'd be like, if you scale up the whole universe and you scale up all the rulers, there's no change. You can't tell if somebody does that. And so, for example, if you change the speed of light, do those other constants also change?

50:40Like the speed of light can be expressed in terms of quantities from electromagnetism, which include things like the vacuum permittivity of space. So if you change the speed of light, you also change those, which change, you know, how electricity works? Or are you somehow breaking the universe and changing the laws of physics themselves? If you change dimensionless constants, you can keep all the laws of physics the same. And every time you change those, you really do get an effect. If you change dimension full constants, then it's more complicated and ambiguous exactly how it propagates through.

51:10But, you know, we can make some simplifying assumptions and play with it anyway. And C, the speed of light, is a dimension full constant, right? Okay. Yeah, because it's meters per second, right? Okay, got it. Has two dimensions to it. And you're right, the speed of light is super duper fast. Like the fastest any human has ever traveled relative to like a nearby object, you know, on Earth is something like 0.0037, the speed of light. Wow. And, you know, that's like astronauts in the space shuttle orbiting the Earth, right? And so we're talking about tiny, tiny fractions, which is why we don't observe relativistic effects.

51:45But you're right. One of the ways that we do notice the speed of light is in terms of what fraction of the universe we can see. We look out into space and we see back to the beginning of time. And we can do that because light takes time to get to us because the speed of light is not infinite. And so the furthest thing we can see is something where the photons were emitted at the very beginning of the universe, essentially like 380 ,000 years after the Big Bang, and have been flying to us ever since. and the speed of light limits how far we can see. So if the speed of light was half what it was, we would be able to see less of the universe because those photons we're seeing now wouldn't have had time to get here if the speed of light was half of it.

52:29So the universe would still be the size that it is, but we wouldn't see as much of it. And how would that impact our understanding of the universe, do you think? Ooh, yeah, that's a really fascinating question. You know, I think we would still see a lot of the structures. Obviously, we could still see the whole solar system and the galaxy and the structures of the galaxy, like the galactic clusters and the nearby galactic clusters. Those are not so far away. And we would still see the early universe. It's just that photons from the early universe were becoming from a closer bit of the early universe than in a scenario where the speed of light was faster.

53:03So to directly answer your question, I don't think that would make a big difference, right? We would still see the whole history of the universe. It's just in a smaller chunk of it. But the chunk we're seeing right now is really, really big. It's big enough that already we can see that when you zoom out, mostly the universe is uniform, right? That there's not a lot of structure at the highest level. I mean, there's solar systems and galaxies and galactic clusters. But once you zoom out past that, it's basically just foam. You know, there's no real structure anywhere. And so we can see enough to get that, which I think is the biggest structure in the universe.

53:37And so it's big enough and the universe is old enough for us to glimpse that. But there is a connection there. You're just a little bubble in the foam of the universe that nobody would notice if it popped. But you know, the structure of the universe also would be different if the speed of light was smaller. Because the speed of light is not just the speed of light, it's the speed of information. And it limits the biggest structure you can make at any point in the universe. Like in order for a structure to form, you have to have it interact and communicate. Like even gravity is limited by the speed of light.

54:11And so there isn't time, for example, to form a structure that's bigger than the speed of light times the age of the universe. It just hasn't had time to like gravitationally assemble. And so if the speed of light is slower, that means the biggest structure you can have would be smaller in the universe. Oh, and so what is the biggest structure that we have? what would be ensmallened by this slower speed of light? Well, this is actually kind of a current mystery because we see structures like the Sloan Great Wall. This is like sheets of galactic clusters, which at the highest level, like the edges of those bubbles in the foam, though some of those are bigger than the speed of light times the age of the universe.

54:52So it's a bit of a puzzle. Like, how did that form? Are we misinterpreting it? Something that we didn't understand. And one of my favorite things about science is that we have all these threads that should all tell one story because we think there's a thing that's happening in the universe. And when they don't, that's a hint that there's something we don't understand. And there's so many different ways to attack the same question. So that's a current mystery. But yeah, some of those biggest structures, you know, super clusters of galaxies woven together into foams and voids would be smaller. So basically like the foam would have smaller bubbles.

55:25Okay. All right. So we've looked at the very big picture. If we go back to Earth, what would be different? So like when I turn on the light switch, I probably wouldn't, there wouldn't be, I'm guessing there wouldn't be like a noticeable difference in how long it took for the room to get right. What about other stuff? Yeah. So the speed of light is so fast that even half the speed of light is crazy fast and there's no way that you would even notice. But we might've been able to measure the speed of light a little bit sooner in our history, right? People tried to measure the speed of light for decades with all sorts of hilarious contraptions with lanterns across mountains.

56:02And basically they were always like, yeah, it's just too fast. We don't know. It's faster than we can measure. So we would have figured that out sooner, which might have given us a handle on relativity earlier. And so I think in that universe, we might have figured out physics 100 or 200 years earlier, which is pretty cool. Oh, then we wouldn't have had Einstein. Because what would he have done? Probably nothing. Somebody else would have been Einstein. Okay. All right. All right. But would he have had the same hair? That's the important question. Really, that's what it all comes down to. This whole production is really just to get us to Einstein's hair.

56:36That's right. That's right. But if you imagine like slowing down the speed of light even more so that its effects are visible every day. Like imagine if cars moving along highways were relativistic. You know, if they were moving at like eight tenths of the speed of light. because the speed of light was crazy slower, then we would have that kind of alien intuition. We would notice relativistic effects every day, right? Like we would see that cars moving along the highway are shrunken and that the people on airplane trips don't age as much, right? And it would really change the experience of going like on a long flight.

57:14You take that 14 hour flight to Dubai, it doesn't feel like 14 hours, right? It only feels like 10 minutes or something. So that's pretty cool. You don't get to watch seven movies, but you also get your time back, right? Yeah. So that would be really cool. But it would also make things really hard. Like, it's already challenging for me to figure out my calendar with time zones. You know, like, which time zone are they in? What does that mean for me? Like, I don't know why that's so complicated. Now imagine that on top of that, you need to take into account relativistic effects. So like, where has Daniel been?

57:46Where is his clock? How much slower is it? It would make coordinating things much more complicated because we'd have to give up on the concept of simultaneity. One of the weirdest consequences of relativity is the fact that clocks are not synchronized, which means you don't all agree on the order of events. And mostly on the surface of the Earth, we can't notice that because everybody's moving very slowly. But if we were moving faster relative to the speed of light, that would be a real effect. And people would disagree about important stuff. And yeah, that could have real consequences. It would make life a lot more complicated.

58:18And just to remind myself, you're talking about if it was more than just half the speed of light, it would have to be quite a bit more. Okay. Yeah, just half the speed of light probably would have almost no measurable effect on life on Earth. Except maybe it would take longer to download a movie from some website in Siberia because the speed of light also influences your download times, right? Like you're downloading data from across the Earth. That's a significant difference. And so the ping time between your computer and that computer is limited by the speed of light because that's the speed signals move across the internet.

58:53And so it would take a little bit longer. You know, in that case, when you're downloading a big movie, the latency is not a big effect. But if you're trying to have like a conversation in real time with somebody on the other side of the earth, then there could be more lags there. Well, I'm glad that the speed of light is what it is then because otherwise it would be hard to record this podcast with you. Yeah, that's true. And then looking out into the cosmos, there would be other changes actually in what we see out there. Black holes would be much more significant. The size of the radius of a black hole depends on the speed of light.

59:27If you calculate the short south radius, the point past which things can't escape the gravity of a black hole, that has a factor in it from the speed of light. It goes like one over the speed of light squared. squared. So if you shrink at the speed of light, that means a larger event horizon for the same mass, right? So black holes with mass in our universe would have a much larger radius in this universe where the speed of light is smaller. This means they could have like a bigger effect on their galaxies, right? We have black holes at the center of all galaxies and they're really massive, but they're not that big.

1:00:00You know, they're tiny compared to the size of a galaxy, but crank down the speed of light by a big factor and they can grow. And so like the centers of galaxies could have like gargantuan black holes, not more massive than the current ones, but just bigger. And that could actually help them grow to more massive quantities. So it would really change black hole physics a lot if you change the speed of light. But we probably would not get sucked up by a black hole. I guess everything could be different if all the black holes were different sizes. In the end, you got to make it about yourself, Kelly, right?

1:00:30What is the impact on Kelly's life? Have you met people? I'm just asking the question that the people are asking themselves. Yeah, you're right. Y 'all are going to be fine. Don't worry. Thank you, Daniel. All right. Well, thank you very much for that question, John. Let us know if we scratched your Doppler itch. Hi, Daniel and Kelly. Thanks a lot for pondering my question. And I really enjoyed listening to your speculation on how our world might be different if the speed of light got cut in half. and I also enjoyed listening to you think about what might happen if we took it to the extreme and it slowed down to like a noticeably slow amount.

1:01:08To be honest, I was hoping for some explanation of how changing the speed of light might be catastrophic to our existence, but I guess in science, it really doesn't depend on what you're hoping for. Thanks a lot and thanks for the show. All right. Thanks very much to everybody who sent in their question. And please, please, please don't be shy. We really do love hearing from you. Write to us questions at danielandkelly.org. Tweet at us, interact with us on Blue Sky, or join us on the Discord. Check out all those directions at danielandkelly.org. See you then.

1:01:44Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio. We would love to hear from you. We really would. We want to know what questions you have about this extraordinary universe. We want to know your thoughts on recent shows, suggestions for future shows. If you contact us, we will get back to you. We really mean it. We answer every message. Email us at questions at danielandkelly.org. Or you can find us on social media. We have accounts on X, Instagram, Blue Sky, and on all of those platforms, you can find us at D &K Universe. Don't be shy. Write to us.

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