Listener Questions #43

25:29It's a natural part of decay and fermentation and microbial life. It would exist even if there weren't humans on earth. It's just something we've captured and manipulated the way that we've manipulated some crops to be larger and tastier and whatever, because we have a certain relationship with it. But we should expect lots of critters to have relationships with it that are going to be complicated and different from the way we do and not easy to anthropomorphize. Yeah, absolutely. And just to put like a nail in how excited humans are about alcohol, though, like if you look at some of the earliest archaeological digs, you'll find vessels that were clearly meant to hold alcohol.

26:07So we've been excited about alcohol for a really long time. And I'd just like to highlight that a lot of my thinking and research for this topic came from a 2025 paper that was making this argument that like ethanol is actually way more widespread than we've given it credit for. And we should be thinking about this question more broadly. And so I do think this is like a sort of new way of thinking about it, which I thought was exciting, which is why I kind of emphasized that here. All right. So, Phil, did I answer your questions? I hope so. Follow up questions. Welcome. Hello, Daniel and Kelly.

26:41Firstly, I feel slightly flabbergasted and honored for two titans of science to spend time on my question. Mostly Kelly. Yes, you've cleared up the alcohol topic nicely. I'm fascinated that it's used to preserve food and destroy bacteria. How the hell did those behaviours come to be? Also, I'm relieved there might not be millions of fruit flies drowning their sorrows, as this is probably not the best answer. As you said, my question was rather broad, so I do have a follow-up. In the evolution of omnivorism, would there have always been a small percentage of genetically determined risk-takers? This would keep the broader population safe while seeking new potentially toxic and fatal food sources using a kind of suicide squad.

27:24And if so, has this been passed on to more complex life? I mean, I have no intention of going to Mars, but some people do. Once again, thank you so much, Phil. Hey, Phil. Thanks for the great follow-up question. So I don't think that there would be genetically determined individuals whose job it was to go out there and eat everything to see if it's toxic or not. In particular, you asked if this would help the broader population. And usually you don't see behaviors that are really bad for an individual but good for the rest of the population. because the genes for that individual that would go out and eat everything and get themselves killed would probably get washed out of the population pretty quick as those individuals kept dying from poisoning.

28:10It could maybe stick around if they were specifically trying stuff and that had a massive fitness benefit for their immediate family. So, for example, if the environment is just loaded with toxic foods and one individual in the family eats those foods first, And then they see what happens and then the rest of the family gets to eat stuff. Like if it was specifically benefiting family members, maybe you could imagine genes for that trait sticking around as long as families that had one of these risky eaters had loads and loads of extra babies. But that said, as far as I know, we don't see populations or families tending to have like an individual who's the one that eats all the risky foods.

28:54At least I don't remember us seeing that in the wild at any point. But that's a fantastic question. Thanks so much.

29:24giving forth helping to make july 4th the largest day of giving in american history it's more than just fireworks join this landmark celebration and get your america's block party tickets now for 17.76 at america 250.org slash la every dating app swap is another loss jimbros fake ceos straight up losers so now the only app i open is moto casino because at least there i'm surrounded by winners real winners thousands of them while everyone else is in the single swamp i'm at home relaxing while stacking bonuses, hitting wins, and playing all my favorite Vegas-style games. Moto Casino, the only app worth your time.

29:59Moto Casino, the social casino. We're prohibited. No purchase necessary. Visit moto.us for more details. Download the Moto Casino app today. Must be 21+. Moto Casino, American Social Casino. Hey, everyone. It's Cal Penn, host of Earsay, the Audible and iHeart Audiobook Club. This week on the podcast, I'm sitting down with Lily Chu, Sue, the author of the Audible original romantic comedy Just Kiss Already. It's a story about a forensic anthropologist who secretly writes mystery novels, an actress who adapts his book into a film, and what happens when a meme and a media tour collide with a slow burn romance.

30:38It's performed by Simu Liu and Philippa Su, and it is an absolute blast. When you actually hear the performance, you realize that other people are taking your words and what you thought was kind of a straightforward sentence like the cat in the corner is black. In my head, it's the cat in the corner is black, not the dog, not the gerbil. But someone else might say it, the cat in the corner is black. That's always fascinating to me. How they just bring in all these different nuances and really make it fun and interesting and distinctive. Listen to Earsay, the Audible and iHeart Audiobook Club on the iHeart Radio app or wherever you get your podcasts.

31:24Aging is real. And so are the benefits of adding vital proteins, collagen peptides to your daily routine. Because around the age of 30, your body needs backup to keep your collagen up to help support healthy hair, skin, nails, bones, and joints. Available in the classic collagen peptides, collagen and protein shakes, and new vital proteins, collagen sparkling waters. so you can stay vital, stay you. Visit vitalproteins.com to learn more and where to buy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

32:00Every sale comes down to a single second. The one between buy now and maybe later. PayPal is built to help your business win that moment. With a checkout experience that feels certain, reliable, and familiar. With a global two-sided network and hundreds of millions of buyers who already know us. All to keep you in control however buying happens next. New markets, new AI-powered selling services. A whole new agentic era where you decide how your business will show up and stand up. PayPal is built to help your business come out ahead. We're built for payments, built for growth, built for agentic.

32:44PayPal Open. Built for all business. Visit PayPalOpen.com to get started. That's PayPalOpen.com.

33:05Okay, we're back and everybody take a sip from your favorite beverage, alcoholic or not, because we are going to be imbibing from the cup of particle physics in a moment. All right. And so, Daniel, who is this next question from? This is from Reg Proctor, who's been emailing me asking me questions about particles and the universe. All right. Let's see what Reg had to say. Hi, Daniel. I have a question about particles and antiparticles. I get it when they annihilate each other because they have opposite charges, But physicists often talk about a particle being its own antiparticle. And my question is, is this like a convenience, like a mathematical construct?

33:48Or is there something real, like a particle is actually different to its antiparticle in some way that no one's ever said? I don't quite understand this, and I'm hoping you can help with it. and obviously because I can't imagine anyone not saying this, but thank you so much for this wonderful podcast. Oh, this is fun. Yes, I love talking about antimatter because there's so many fun wrinkles here and interesting philosophical nuances but antimatter is such a big place in the public conception of particle physics in a way that I think is often misrepresented and people come away confused and so I'm always excited about an opportunity to dig into it and break it down.

34:31Well, let's break it down then, starting with antiparticles. What the heck are antiparticles? Yeah, so antiparticles are not some special fancy thing. They're just particle physicists doing their thing, which means looking for patterns and symmetries. You know, the basic process of physics is let's look at everything in the universe and then let's try to explain it in terms of a small number of ideas or rules, right? We don't just want to list everything that happens in the universe. We're reductionist. We want to come up with like a compact, tidy explanation. And that means if you see two things that are similar, you treat them as similar.

35:06You respect that similarity. So for example, we see the electron, right? It's a thing in the universe. And then we found another particle called the muon. And we weren't just like, there's an electron, there's a muon. We were like, wow, these two things are very similar. In fact, they're almost identical, but one is heavier. Let's see if that pattern happens elsewhere. And it does. Every particle we've discovered has a heavier version. So we categorize them in this way. We're looking for patterns, for symmetries. It's sort of similar to the way we build the periodic table of the elements, right?

35:36We slot everything into where it belongs and we look for patterns. These are metals and those are not metals. So particles and antiparticles are just part of that game. We found electrons and we also noticed that there are other particles that are just like the electron, but have the opposite charge. So we call that a positron or an anti-electron. And the muon also has a positively charged version. And the quarks also have oppositely charged versions. So this is a symmetry. It's like a mirror in our world that says particles don't exist on their own. They have a partner. And anytime you have something in a partner that are related by some transformation, some symmetry, then you're curious about that.

36:19What does that mean about the universe that it can do A and the opposite of A at the same time? Are we looking at something that are two sides of the same coin? We should be treating them as a whole instead of investigating them individually with the way that, for example, we've made great insights by combining electricity and magnetism into one concept. It makes much more sense mathematically. It gives us insight into special relativity. We shouldn't treat positrons as just another kind of particle that happened to be similar to electrons. we should acknowledge this relationship and hope that that gives us some insight into how the universe works.

36:52Yeah. I remember when I first learned about this concept, I was confused about why protons weren't the antiparticle for electrons. But the answer is that protons, yes, they have the opposite charge, but they don't weigh the same amount. So there's something totally different. Yeah, that's exactly right. And you put your finger on the crucial concept for antiparticles because there's nothing anti about a particle. You can't look at a particle and say, this one's a particle, this one's an antiparticle. The particle-antiparticle thing is a relationship. You have a pair and you say, these are related by the particle-antiparticle relationship, which means you take one of them, you flip the charges, you get the other one.

37:33Okay. Right? And so it's a relationship between two particles. And the relationship is symmetric. So if you gave me an electron and an antielectron and you said, Daniel, which one is the particle and which one is the antiparticle? I would say, it doesn't matter. You could label either one matter and the other one antimatter. It's arbitrary. We happen to call the ones that are around a lot particles and the ones that aren't around a lot antiparticles, because that's just historically how we started. It would have been weird to start off calling everything antimatter. So that's just historical, but it's about the relationship.

38:06And so as you say, if you take an electron and you flip its charge, then you get a positively charged electron that's not the same as a proton, right? They're different mass, they have different constituents, one has a hydronic interaction, one doesn't. So a positron and a proton are very different things. Whereas a positron and an electron are only different in these charges. You flip the charges, you get the other particle. Yeah, I was going to highlight that hydronic thing because I totally know what that means. But is this another example of physicists not doing a great job of naming things?

38:39Like instead of particle, anti-particle, should it have been like particle, oppo-particle, or like opposite particle, or oppo-charge, or like, anti just seems confusing. No, that's a fair question. Anti does seem confusing. It feels like it's in opposition. It's like against us or something. They're fighting back or something. I do think that after understanding something more fully, we will give things better names, definitely different names, because we understand it more broadly and in the right context. So like, what would I name particles and antiparticles with this knowledge? I would give them names that reflect that they are part of something larger, but that there's a symmetry there.

39:20And so - Simiparticles.

39:27Flipicles. Flipicles is pretty good. I would choose a name that reflects that, for example, a positron, it's not really its own particle. It's just another kind of electron. And so the electron has really two different ways to be, right? There's the positive and the negative version of the electron. They really are two sides of the same coin. And so you can't call the whole system an electron because we already think of that as naming one of them. So you'd have to come up with a totally different name and then you'd give them like, you know, call Danielon, the positive and negative Danielon. Okay, all right.

40:08Let's pull ourselves out of this hole. You and I keep digging holes and then getting stuck. So tell me, what would you do if you had a particle that had no charge? Like what about neutrons? Do neutrons have flipicles? All right, great question. And so I said earlier that the particle-antiparticle relationship is about flipping the charge. But it's not just flipping the electric charge. Particles also carry a bunch of other things like lepton number and baryon number. these things that particles keep track of and respect when they have interactions. So the universe, for reasons we don't understand, keeps track of like the number of electrons in the universe.

40:43And you can't just like create or destroy electrons because that would violate this rule that the number of electrons can't change. We don't know why that rule exists, but we've observed it. We know the universe respects it. And so electrons carry this electron number to them and anti-electrons have the opposite. So when you flip a particle to the antiparticle, you flip its electric charge and also its lepton number and a couple other bookkeeping numbers. All right. But you ask a great question, which is what happens for a particle with zero charge, right? And so let's take an easy case first because the neutron is complicated.

41:15Let's take the photon. The photon has no charge. It also doesn't carry any of these other numbers, lepton number, barium number, all zero. So you take the photon and you flip all those charges. What do you get? You get the photon, right? So that's why we say the photon is its own antiparticle. It has no flippicle. That sounds like a tasty afternoon frozen treat. Oh, it does. You're right. You're right. But that might make people like physics more. Oh, look, the flippicle truck is coming. Let's go get one. Yay. Oh man, it just has photons. So in that sense, like the photon is its own particle is just a statement of what happens when you take the photon and you do this transformation to it.

41:58The one that's supposed to take you from particle to antiparticle or from antiparticle to particle. That doesn't mean that the photon is an antiparticle. Remember, there's nothing anti about an antiparticle. It's about a relationship. So it has this relationship with itself. Say, for example, that your face is like perfectly symmetric. You're like a beauty model or whatever. So you stand in a mirror and you flip your image and it looks exactly the same. My face is quite antisymmetric. My ear is higher on one side. My beard is very differently shaped on the other side. If you flip me, then you get like the anti-Daniel, right?

42:31Right. But if you have a perfectly symmetric face, then if you swap left and right, you get your face. Right. So you are your own antiperson. You are your own reflection. Whereas I'm not my reflection. I see my reflection in the mirror. I'm like, that's a different person. That's not me. Right. So photon has that relationship with itself. Okay. And the same is true for the Higgs boson. The same is true for the Z boson. It might be true for neutrinos. We don't know. What? Yeah, exactly. Get to work. Yes. So neutrinos might be particles the way that quarks and electrons are in that they have antiparticles, which would mean they get their mass from the Higgs boson.

43:08Because to get your mass from the Higgs, you have to have an antiparticle as well. You can't do it on your own. See, this is one example of how electrons and positrons are not different things. When they get their mass from the Higgs, they work together to get their mass from the Higgs. They can't do it by themselves. We don't know if neutrinos do that. If they do, it would be really weird because then they would get only a tiny little mass, which would need its own explanation. There's a whole other fun theory about how neutrinos might be their own antiparticles. It's a Majorana particle. And that would very naturally explain why they have so little mass.

43:40All right, so let's get to your question about neutrons. Neutrons are neutral, hence the beautifully chosen name. Good job, guys, on that one. Does that mean that they are their own antiparticle? Well, no, because they have other charges. They carry these baryon numbers, et cetera. And those things are not zero for the neutron. More concretely, a neutron is made out of quarks and quarks have antiparticles. So for example, a neutron has one up quark and two down quarks. An antineutron has one anti-up and two anti-down quarks. Now they're both electrically neutral, but they have very different internal bits and they carry different baryon numbers.

44:19So a neutron is not its own antiparticle. There is an antineutron. Got it. Okay, I'll admit my brain is still catching up. My first thought was if you have one up and two down, shouldn't you just have one down and two up? But now I remember that the up and the down have different masses, and that would be something totally different. Yeah, exactly. All right, my brain caught up. Yes. So the anti-neutron is built out of the anti-quarks, whereas the neutron is built out of the quarks. Okay. And quarks do have antiparticles. They are not their own antiparticle. They have these weird electric charges, one-third and two-thirds.

44:51It's kind of crazy. Okay. All right. So back to Reg's question. He's asking, are particles being their own particles a convenience, like a mathematical construct, or is it something real? Well, it is a mathematical relationship between particles, this particle-antiparticle pair thing. It's a relationship. It's an example of a symmetry. Some particles really are their own antiparticles in the sense that if you transform them from particle to antiparticle, you're back to where you start. So I hope that answers your question. And I said earlier that thinking about particles and antiparticles together can help us understand the universe more deeply.

45:26An example of that is that we sort of left this whole particle-antiparticle picture behind a little bit because we've sewn particles together into a more unified theory, which is quantum field theory. So we don't think of particles as the fundamental basis of the universe anymore. We think of them as ripples in fields. and there's an opportunity here to recognize that electrons for example and positrons have a deep relationship because in quantum field theory they don't come from two different fields they come from the same field there is just the one field that can do two different kinds of ripples one of those ripples is the electron the other ripple is the positron so you see how they're deeply deeply woven together and that's reflected naturally and natively in quantum field theory.

46:14And so identifying that relationship is more than just like, hey, this is a cute construct or this is a cute thing we discovered. It was a clue towards understanding the universe much more deeply. So the electromagnetic field, for example, which has the photon as its particle, can only ripple in one way. It ripples like the photon. There's no other way for it to ripple that you would call an antiphoton. And so we have different kinds of fields, can do different kinds of ripples. and that's why some particles are their own antiparticles and some particles are not. But all of them, I hope, will buy from Kelly's Fliperon afternoon treat truck when it comes around.

46:49I hope so too. Well, I could use a drink, so let's take a break and see what Reg had to say about this very informative answer. Thank you, Daniel. That really does answer my question, especially understanding that this is all coming from quantum field theory. That helps visualize why particles and antiparticles always annihilate, being there from the same quantum field. Although now that I think about it, I think there was a slightly deeper question that I did not properly articulate. When I was asking whether this is a mathematical convenience, I think what was going through my mind was, is this just a way for scientists to say that every single particle has an antiparticle, even if it doesn't have, you know, a counter-charged particle just to make it better for the standard model?

47:38Or does that actually do something practical, as in it defines how it interacts in some way in the math or something? Yeah, it's a good question. What's the benefit of calling a photon its own antiparticle? Does it matter? Well, there's no practical benefit. It's not necessary for the standard model and it doesn't change its predictions at all. It's just a matter of consistency because particle and antiparticles are a relationship rather than a label or an assignment. It makes logical and mathematical sense to say the photon has this relationship with itself as opposed to electrons that have that relationship with positrons.

48:21But it makes no practical difference. If you instead said particles and antiparticles just don't apply to neutral things like photons, that would change nothing about physics.

49:19We'll be right back. with huge, huge bonus rounds. Moto Casino adds new games and awards players free coins every single day. Grip it and spend it on Moto Casino. Download the Moto Casino app today. Moto Casino is a social casino. What you're prohibited, no purchase necessary. Visit Moto.us for more details. Moto Casino, America's social casino. Hey everyone, it's Cal Penn. I'm the host of Ear Say, the Audible and iHeart Audiobook Club. This week on the podcast, I am sitting down with Ray Porter, the narrator of Andy Weir's audiobook Project Hail Mary, massive sci-fi adventure about survival and science and what happens when you wake up alone very far from Earth.

50:06I really had to make a decision because I caught myself getting that frog in my throat and starting to get teary as I'm narrating some of these sections. And it's like, okay, yo, yo, yo, is this indulgent? And I really thought about it. I was like, no, at this point, it would kind of be betraying the trust the author and the listener have in telling this story if I don't go through it. But there's places in this book that deeply emotionally affected me, and I left it on the mic. That's great. Because it served the story. People will say like, oh my God, I cried at the end. It's like, yeah, dude, me too.

50:38Listen 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 adding Vital Proteins Collagen Peptides to your daily routine. Because around the age of 30, your body needs backup to keep your collagen up. To help support healthy hair, skin, nails, bones, and joints. Available in the classic collagen peptides. Collagen and protein shakes. And new Vital Proteins Collagen Sparkling Waters. So you can stay vital, stay you. Visit VitalProteins.com to learn more and where to buy. These statements have not been evaluated by the Food and Drug Administration.

51:14This product is not intended to diagnose, treat, cure, or prevent any disease.

51:44Keep you in control. However buying happens next. New markets. New AI-powered selling services. A whole new agentic era where you decide how your business will show up and stand up. PayPal is built to help your business come out ahead. We're built for payments. Built for growth. Built for agentic. PayPal Open. Built for all business. Visit paypalopen.com to get started. That's paypalopen.com.

52:28All right, man, Doug had some questions.

52:35This is the episode about drinking stuff today. Yes, yes. Kelly, what were you sipping while you were working on this? is like a nice Earl Grey tea or bubbly water. It was bubbly water without a lot of salt in it. And let's go ahead and listen to all of Doug's questions and then we'll dig in a little bit more. All right. Hi, Daniel and Kelly. Ocean water is too salty for us to drink. We end up thirstier than before we drank it. But saltwater fish, sea turtles, seals, walruses, dolphins, and whales live in it just fine. There must also be saltwater-tolerant birds. Are there saltwater-tolerant land animals?

53:17Which animals that currently find the ocean water too salty evolved from animals that lived before the ocean was as salty as now? Which evolved away from saltwater tolerance because they found freshwater sources, ponds, lakes, and rivers? Which species live near the mouths of streams and rivers in order to get a drink that's not too salty? Our cells are saltier than freshwater, but not as salty as the ocean. Do saltwater-tolerant species just have saltier cells, or do their bodies desalinate the water? When we eat a saltwater fish, do we need to drink extra water to offset the extra salt? Why not?

53:59What would it take to make a saltwater-tolerant species from a non-saltwater-tolerant species? Could scientists implant a gene like the one that made fluorescent fish? All right. Doug is very curious about saltwater. And I've often wondered that myself. You know, like, you're in the ocean, you can die of thirst. Water, water everywhere and not a drop to drink. That's right. Why is that, Kelly? Tell us. Wow. How literate. And so, or how literary. I mean, I know you're literate. That was for Zach's benefit there. That's right. That's right. He's going to judge us somehow. But okay, so what problems are caused by saltwater?

54:36The answer is a lot of them. All right, so there's this idea that you try to reach equal concentrations of things like salt on both sides of permeable membranes like our cells. So a permeable membrane is a membrane where something can go across it in either direction. And so if you have fresh water on one side of the permeable membrane and salt water on the other, the salt is going to flow over to the freshwater side until it's reached an equilibrium. Does that make sense? All right. So I think you're telling me that when you have salt water near freshwater, that the salt molecules don't like to stay on one side.

55:11They like to spread out and things get sloshed around evenly. Yes, exactly. We have, and this is surprisingly consistent across different cells and different organisms, like a set amount of potassium ions in our cells and a set amount of sodium. So salt is sodium chloride. And so if you have salt water and you have a set amount of salt inside of your cell, but then you surround that cell in a saltier environment, you're going to end up with a bunch of salt going into the cell. Okay. And this can cause a lot of different problems. One of the problems has to do with protein folding. So folks might remember that we had Benjamin DeBevoer on the show, and Daniel and Benjamin had this conversation about how— I'm terrified because I don't remember this.

55:56That's all right. It was fascinating. It was fascinating. So you make a protein, and proteins have these charges, and based on the charges, that determines how they fold up. And the way a protein folds up impacts what that protein does. Does that make sense? Yeah. Okay. So a lot of what's holding that protein together are pretty weak charges. And so if you end up with a bunch of charged sodium particles in an environment, that can pull your proteins apart. And now they no longer have the right shape. They can't do the things that they're supposed to do. This can also mess with the way that DNA holds itself together and folds up.

56:33And so basically, if you start ending up with a bunch of extra charged particles going in there, it messes up the way all of the stuff inside the cell is sort of held together, and it can't do what it needs to do anymore. All right. So, so far, I understand that if you're in a saltwater bath, you're going to end up absorbing that salt, and that having too much salt inside you messes up some of the basic biochemistry, like how DNA gets turned into proteins and how those proteins do their job. Yep. I guess I'm confused because I thought life began in the ocean and I thought of us land creatures as basically walking bags of ocean bringing that environment with us.

57:10But now you're telling me that like salt water in the ocean is bad for life. How does that work? So salt concentrations are not the same everywhere you go. Salt environments can vary from less than one part per thousand of sodium chloride or salt in the water to over 400 parts per thousand in super saline environments. And so basically the thing that you need to know there doesn't really matter what those numbers are. There's just tons of variability. And so if our bodies are adapted to a certain amount of salt in our cells, and maybe that reflects our saltwater past, we're still wanting to move between a bunch of different kinds of environments with different concentrations of salt.

57:49So just because we do okay at one concentration doesn't mean we'll do okay at all concentrations. Plus, you and I are very far removed from our salt environment. Okay. And so we don't have super great ways of dealing with excess amounts of salt. So our kidneys do what they can to remove salt from our blood so that it doesn't go throughout our bodies and mess with all of our other cells. So it removes the salt from our blood and then you pee excess salt out. So if you have too much salt in your diet, your kidneys try to remove it and pee out the extra so that you can maintain the right concentration.

58:21Does that make sense? Yeah. So you're telling me that Daniel's picture of we all came from the sea is too naive because we've come from a wide variety of different environments with more salt or less salt. And we've evolved so that our chemical processes do what we need to. And that requires a certain salt concentration, which might be different from what we encounter. And so our kidneys and our bodies do their job to try to maintain the right salt concentration. But it's tough. Yeah. I mean, and also we and many organisms live in environments where salt concentrations fluctuate. Right. Right.

58:54Exactly. So you've got to be a little bit robust to it. That's right. Yeah. You need to be robust to it. And so the way mammals are robust to it is we have kidneys that try to extract salt when we've consumed too much salt. Like pizza night? Like pizza night or ramen night. Gotta love ramen night. That's why it's so good. I know. It's so good. And then my blood pressure is like, woo, through the roof because too much salt is bad for you. Oh. Okay, so, but Doug had a lot of questions about how different animals respond to this. Okay. And these are great questions and I learned a lot. Okay, so, one of the questions was about what happens if you have, like, turtles or birds or animals that, like, are, you know, maybe not fish that are encountering a lot of salt, how do they deal with it?

59:40And the answer is that a lot of these animals have glands in their face where when you first take the salt in, like maybe you're taking a drink of salt water, it actively extracts the salt out of the water and concentrates it so that it can then get like extracted through specialized holes in the head. So, for example, there are marine iguanas in the Galapagos Islands that can live on land, but they also swim in the water. And they extract the salt out of the water that they're consuming while they're eating plants underwater and stuff like that. And then, like a snot rocket, they shoot it out of their face.

1:00:21And you should watch videos of this because it's crazy. And apparently they sometimes use it to scare off predators or mess with competitors. but they're like, and then there's salts, like big chunks of salt, like spraying out of their face with some snot. And it is gloriously disgusting. Snot rocket is a great name though. Yeah. Makes me wonder if it's one of the things you're selling in your flippicle truck. Oh, well, you know, why not? And so anyway, okay. And so birds also, like, so birds that eat salty fish also have these glands that actively pull salt out of stuff and then concentrate the salt and then expel the salt through these holes in like their beak.

1:01:01The way sharks do it is their bodies actively pull out salt and then they excrete concentrated salt out of their rectum. Whoa. Yeah. That's not a salt rocket. That's something else. Yeah. Out of a rectal gland. Not just their rectum, but a rectal gland. It's a poop rocket. It's a... It's a salty fart. I don't know. Oh, yeah. That's too... I'm not buying that from the ice cream truck. Yeah, yeah, no, I don't think I'm selling that in my ice cream truck. Okay. And sometimes if you see turtles that live in the ocean, like eating jellyfish or whatever, and then they come up to lay their eggs on land, it looks like they're crying.

1:01:41And what's happening is they have glands near their eyes where they excrete the salt out from like the sides of their eyes. And so it looks like they're crying, looks like they've got tears, but they're just excreting the salt in high concentrations out of their face. Wow. Okay. So how do fish do it? Fish are kind of amazing. So fish have this very energetically expensive process where their gills are able to tinker with the amount of sodium and potassium that's like getting into the body. Wow. How did they do that? I'm not going into detailed biochemistry. I've given you the broad strokes, man.

1:02:16There were a lot of questions here. So, all right. So what they do, like if you're in a freshwater environment, you actually need to hold on to salts because there might not be enough salt in the water to help you maintain the salt that you need inside of your cells. And so cells in the gills, in those cases, are pulling salt in. But if you are in a saltwater environment, there might be too much salt. And so those cells in the gills are actively pushing or keeping salt or sodium ions out. But fish are able to what's called remodel their gills depending on their environment. So there are fish that go from freshwater to saltwater or saltwater to freshwater depending on what stage of their life they're in.

1:02:59And as they start to change salinity, their gills can kill off cells that do one function. For example, try to suck up the sodium ions and then replace them with cells that do the opposite thing like cells that try to kick out the sodium ions. Wow. How quickly can they do that? Couple days. Takes like one to three days or something. But like still, that's amazing. Like they've got this procedure for like killing off cells that are like not doing what they need them to do right now and replacing them with cells that do the correct thing. But it's worth noting that this is very energetically expensive.

1:03:30And so if you take a fish and you move it from a saltwater environment to a freshwater environment and needs to do all of this remodeling, it might reduce its energy because now it doesn't have energy to like move around as much because its body is using its energy to kill off some cells and build new ones. It might grow more slowly. It might have fewer babies. It's very stressful for an organism to adapt to a different kind of environment or to fix the damage that happens to their body after they've been put in the wrong kind of environment. So, for example, if you're exposed to a high saltwater environment and your proteins start to, like, change their configuration, there's some things that you can do.

1:04:07So sometimes you need to kill that cell if things are just too much of a mess and be like, nope, starting over. But there are proteins you can make called heat shock proteins that help you sort of put things back together. And so the point is animals have ways for dealing with this kind of stuff. But whenever you're asking them to make a change or if you're just asking them to live in super saltwater environments in general, that takes a lot of like calories and energy to be actively moderating the concentration of salt inside of the body. Yeah, well, that makes a lot of sense. That doesn't seem like an easy thing to switch to do.

1:04:38I can't just like switch to being able to drink saltwater no matter how much energy I spend. Yeah, no, you'd be a goner. Total goner. Doug had a great question about animals that are in environments that are changing their salinity. And this is a really relevant question right now because as global climate change is happening, you get environments where saltwater is inundating land and areas that were once freshwater. And part of that is because sea levels are rising as things like icebergs are melting. and so as seawater gets farther inland and gets into like ponds and lakes and streams and stuff that used to be freshwater you now have a lot of animals that are encountering salt water that weren't meant to encounter salt water and global climate change is changing where you end up getting a lot of precipitation so you get some environments that used to be super salty but if they get a lot of extra rain then that water becomes dilute and now it doesn't have as much salt as it had before Makes sense.

1:05:37And so the question is, what's happening to these animals? Some animals are just paying a higher energetic cost, and their body is able to adapt and deal with it. But more of their energy is going towards just trying to survive in this environment that has different amounts of salt than it had before. And is the salinity changing kind of rapidly, like a huge rainstorm, and now it's more fresh? And then a drought, and it gradually gets salty and salty? It depends on where you are and what kind of volume of water you're working with. And so, you know, like a huge volume of water, it can take a long time to change the salinity of that.

1:06:11But if you're, you know, working in a pretty small pond and then it gets inundated by the ocean for the first time, that can be a pretty massive change in salinity. So it depends. So it depends. So there was a paper that was looking at what animals are most susceptible to like essentially dying during these changes. And they found things like freshwater turtles. Oh. I know I love freshwater turtles. But if there's freshwater bodies that they can get to in the area, they can behaviorally deal with this. But, you know, you've got to make sure they've got somewhere to go. Fish often do a pretty good job of dealing with it because they can do this gill remodeling.

1:06:46Not all species can do that. But fish as a group seem to be pretty well placed to deal with global climate change. And I'm sure there's going to be a lot of people who are like, no, they're not. Fish have a lot of other things to worry about also. They got mortgages. They got kids to raise. Yeah, yeah. Okay, I'm going to backpedal and say that global climate change is going to be catastrophic for a lot of fish species. Some of them will be able to handle the changes in salinity better than others. All right. Other animals that are pretty susceptible are zooplankton. So these are little aquatic crustaceans.

1:07:18And you might be like, little aquatic crustaceans. I can't even see them. Who cares? Point is, you need them to - I'm not so callous. I like those little aquatic crustaceans. I saw you yawn when I said zooplankton. I saw it. I saw it. I was going to yawn at that moment anyway. I love zooplankton. Really, tell me more. Well, they are food for lots of other things. So maybe the fish can handle the salinity changes, but they might not be able to handle their food, which couldn't handle the salinity changes biting the dust. So these things are complicated. Yeah. Well, the whole ecosystem is sensitive to salt, right?

1:07:52So it makes sense that as things are changing, everything is going to get skewed. Yep. Yep. That's right. And amphibians are also particularly sensitive because their skin is particularly permeable. And so if they're in a more saltwater environment, that salt is going to rush through their skin and get into their bodies. All right. So let's say this is Doug's last question. He wanted to know if you could make a saltwater tolerant species tolerant to freshwater. Essentially, could you take a gene and make it so that an organism that was freshwater could now live in saltwater or an organism that was adapted to saltwater can now live in freshwater?

1:08:29Yeah, good question. Yeah, great question. I think the answer is not a gene. I don't think we understand this at the gene level. Right. But like what we've talked about requires multiple levels and these are very complicated mechanisms where more than one thing is going on. So like for the GIL remodeling, there's some genes that are associated with destroying the old cells, other cells that are associated with building in the new cells. And I don't think we have all of those genes identified. And even if we did, genes usually have multiple functions. So if you took a bunch of genes from one species and moved them into another, you could like mess up a bunch of stuff.

1:09:07And so I don't think that we could at the moment with what we know turn a freshwater species into a totally saltwater species or a saltwater species into a totally freshwater species with genetic engineering. Maybe one day? Because every organism is a huge Rube Goldberg machine that we do not understand and we can mash the buttons, but there's like millions of them. So who knows what knobs you have to turn to make things happen. I would like to get a shirt that says that. And it has, you know, quote by Daniel, Daniel and Kelly's Extraordinary Universe. And there's the Daniel quote, because one, I totally agree.

1:09:43And two, the number of times listeners write to me and say, as Daniel says, our body's a huge Rube Goldberg machine or whatever. And I'm like, yes, yes, Daniel says that. And they're totally right. I'm not tired of hearing about it. I'm just like, man, that thing that Daniel said really sticks with people. Okay, that's funny. I didn't realize that. Well, I'm feeling totally pickled and thoroughly brined and marinating in this answer. Let's see if it works for the listener. So, to summarize, all earth animals must have a similar level of cell saltiness. Otherwise, proteins and DNA wouldn't work right.

1:10:20Saltwater-tolerant animals evolved organs and processes to eject excess salt. Animals that are not saltwater tolerant likely evolved away from tolerance due to local abundant freshwater sources. To make a non-saltwater tolerant species into a saltwater tolerant species, you'd have to add or modify a whole organ system and perhaps teach the animal to use it, a tall order indeed. I'm still wondering whether life evolved in a less salty ocean, and how do single-celled life, plankton and plants tolerate salt. But that can wait for another episode. Thanks. All right. Thank you very much to everybody who writes to us, who engages us with your curiosity.

1:11:05We will ferment your questions. We will pickle ourselves in your conundrums. We really want to scratch your itches. We want to reflect on it. We want to show you the beautiful symmetry of the universe. Or we want to be able to say, it depends in a whole new context. So please send your questions to questions at danielandkelly.org. We look forward to hearing from you.

1:11:33Thanks, everybody, for listening. Please go and do us a favor and rate the show on whatever podcast app you're using. It really helps people find us. Daniel and Kelly's Extraordinary Universe is edited by the amazing Matt Kesselman. He really is a wizard. You can also find us online on Blue Sky, Instagram, and XDNKUniverse. Come engage with us. You can email us at questions at danielandkelly.org. We really do want to hear from you. And you can find our website, www.danielandkelly.org, where you'll also find an invitation to join our Discord, where everybody comes and talks about the amazing universe.

1:12:12And we also have the most amazing moderators. This is an iHeart Podcast. Thanks for joining us.

1:12:45your America's Block Party tickets now for$17.76 at America250.org slash LA. Hi, Uncle Lazer here. America's built on fast cars, fast food, and even faster women. Moto Casino's built in America. You know what they're fast at? Fast cash prize redemption. You see, only Moto is U.S. owned and operated. Moto. It's American made. That's who we are, and that's who we care about. Play for free at Moto.US. Moto Casino, the social casino. Avoid were prohibited. No purchase necessary. Visit Moto.us for more details. Must be 21+. Moto Casino. America's social casino. Identity theft can cost more than you think.

1:13:25Drained investment accounts, stolen tax returns, lost wages, expenses for lawyers. It's a lot. That's why LifeLock is backed by the Million Dollar Protection Package, which covers up to$1 million each for stolen funds, fees for experts and lawyers, and out-of-pocket expenses. Don't face the burden of identity theft alone. Protect your future and finances with LifeLock. Join now and save up to 30 % your first year at lifelock.com slash iHeart. Terms apply. Hey everyone, it's Cal Penn. I'm inviting you to join the best sounding book club you've ever heard with my podcast, Earsay, the Audible and iHeart Audiobook Club.

1:14:03Every episode, I nerd out with amazing guests and dive into the best new audiobooks available on Audible. It's the book club for your ears. Listen to Earsay, the Audible and iHeart Audiobook Club on the iHeartRadio app or wherever you get your podcasts.

1:14:42while you spend with spending accounts and savings tools with great rates. No tricks, no hidden fees. Banking built for life today. Learn more at ally.com. Ally Bank. Member FDIC. This is an iHeart Podcast. Guaranteed human.