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The Chemistry of Life with Kate the Chemist

October 13, 202642 min · 7,801 words

Show notes

Would aliens use the same periodic table as us? Neil deGrasse Tyson and comic co-host Negin Farsad sit down with Kate Biberdorf, aka Kate the Chemist, to tackle fan questions about the chemistry of life, diamonds, how fire works, and spontaneous combustion.

Highlighted moments

so you're never going to have liquid diamond because that's like having a liquid solid.
7:21

Transcript

Welcome Kate the Chemist

0:00Nagin, I want to be a kid again so I can do all those chemistry experiments that Kate the Chemist is talking about. Oh my god, the messier the better. But then who's going to clean up? I have to clean up. And that's when the experiment goes wrong. That's the end of the experiment right there. Coming up, Kate the Chemist on StarTalk. Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

0:36This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. I got with me, Nagin Farsad. Nagin, welcome back. Hello. I'm your personal so far from being an astrophysicist. Hello. You are my personal co-host. How's that? There we go. That's accurate. You know what we don't do often enough on this show is chemistry. We don't. And when we want to do more of it, there's only one go-to person in the universe. Well, there might be others,

1:12but the one we got our eyes on. In our universe, yeah. It's our universe. We're going to have Kate Bieberdorf. Kate the Chemist. Kate, welcome back to StarTalk. Thank you for having me. I'm so excited to be here. So you are a professor of the public understanding of science. Were you that the last time we talked? Maybe. If it was after September 2024, that's when I started working at Notre Dame. It's been so much fun. Oh, no, no, no. It was before that. I think it might have been before then. So you're a professor

1:43of the public understanding of science at Notre Dame. Yes, I am. In the Department of Chemistry and Biochemistry. And you were the first professor to hold that title. So first, congratulations on that new title. Certainly deeply earned, given your output. And some of my favorite, like you've got a few books out there. It's Elemental, the hidden chemistry in everything. You know, some chemistry is not all that hidden. You know, when stuff blows up, that's not hidden.

2:13No, it's not hidden. But it's literally everywhere. Just this morning, I did a thing with the Today Show. And the lady who was doing my hair was like, there's science in this. I was like, yeah, babe, there's science everywhere. So it's just really nice to like hear that. And people see it now when we start talking about it more. And that's thanks to people like you. Wait, wait. Were there cameras in your hair and makeup session? Because you could have like doubled down on that. Turn that into an experiment with hairspray. I know. You must have an experiment with hairspray. Yes. For sure. It's so flammable. I think every scientist has tested that once or twice.

2:46It's completely flammable. Completely flammable. Also, the big book of experiments. And but that's not my favorite title. It's the awesome book of edible experiments for kids, which sounds like you're just taking the kitchen and turning it into a laboratory. Yes, that's exactly what I did. I wrote that during COVID. I opened up my pantry and was like, what do I have in here? How can I turn this into science experiments? I think it kept me sane during the pandemic, but it was so much fun to write because I like to bake. There's a lot of

3:16chemistry in baking, but the cooking stresses me out. So these are all kind of like baking experiments and really fun. I enjoyed it a lot. Yeah, excellent. I'm a baker too. And I'm always amazed you just put in this, you just make this batter and then it becomes something completely different in the oven. It's, you know, I don't think enough of us are astonished by this fact when you think about it. I mean, it's just a complete transformation of properties. Except for when you're doing it wrong, in which case I made, I made just the simplest of just rice.

3:50I just made rice the other day for like a dinner party and I turned it into mush. So that was a chemistry experience experiment that I did very incorrectly. Less time I'm attending your dinner party. Yeah, yeah, yeah, yeah, yeah. No.

4:06Everyone say no to me. And of course, Kate, you have a podcast called Seeking a Scientist. And how would you subtitle that? We go after very fun questions and try to find answers to them. So it started off with a very sci-fi feel. But as we transition, it's more like, I read this cool book asking, are plants intelligent? Can I get the scientists on here and talk to them about it? I've also talked to NASA astronauts, Kate Rubins. She talked, she was the first person to sequence

4:37DNA in space. So I was able to talk to her about her experience. So it's just all about asking nerdy questions. And I'm just very honored to be the host of it. And that scientists like you will come on there every once in a while and add their opinions and their thoughts on it. And it's just really fun. Yeah. Well, and until plants can do long division, I'm not saying they're intelligent. Okay. I have my standards. It was interesting, though, because like the whole conversation is like, what does it mean to be intelligent? So we started off by defining that, right? And so at the beginning, I was so like,

5:09no, absolutely not. That's such a wild idea. But by the end, my brain was kind of open. It's like, how are we defining intelligence? And could plants be using some kind of system to communicate with other plants? And I think the answer is yes, a little bit. So it's a wild idea. Yeah, that's that. What do they call that underground? The myocelium, where the plants communicate with each other. Yeah. Huge. But I'm kind of, I'm kind of glad plants can't walk. Because same, they would just exact revenge on us. Completely.

5:40Well, I feel like I feel like that show Last of Us on HBO has really terrified, like a generation of viewers into the possibility of what plants can do. And the like, the like mycelium, whatever walkie talkie network of communication that they have. Right. Exactly. Exactly. Kate, you're on for an

Liquid diamond physics

5:59installment of Cosmic Queries. We've collected several for you. In this episode, they're directly for you. And Nagin, you have you have these, all these questions? Yeah, are we ready? Ready? I'm ready. Let's do it. I'm so excited. Okay, no, you're gonna like these, you guys. They're really fun. All right. So hello, this is Stacey Hughes from Nebraska. I was disappointed to find out that diamond rain on other planets is made from microscopic crystals, as crystal lattices are perhaps the only form of macroscopic molecules. Is it possible for molecules that size to exist in

6:36liquid form? If not, what would the texture of a lake of visibly sized liquid diamond be? Would it feel like swimming in or bees? Okay, so much going on there. Wow.

6:50Wait, I gotta, let me just pull out one thing. What is a liquid crystal? So a liquid in general is going to be something that is going to fill its container. So if we pour water into a glass, it's going to fill from the bottom all the way up to the top. And so it's just going to take its space. But what I'm bumping on with a question is that we're saying liquid diamond. And so diamond is a solid structure of carbon. So if you look at the phase diagram of carbon, you're going to see four different things. You'll see the gas, you'll see the liquid, and then the solid is broken

7:21up into two things. You've got diamond and graphite. And so you're never going to have liquid diamond because that's like having a liquid solid. Does that make sense? So it's not, they're two completely different phases. So you would never be able to swim in liquid diamond, but could you swim in liquid carbon? Yes, but it would be the hottest temperature ever, the hottest pressure ever, you would be able to enjoy it for about a nanosecond before you vaporize. So a lot of things going on with that question. Is it like a really efficient, like hot bath? A hot bath you only need for a nanosecond to do all its wonders.

7:55I guess, yes, but you would not survive. I mean, we are talking about pressures that are so, so high, like maybe 10,000 atmospheres. And on Earth, it's one ATM. So I mean, you are not living in this. You will not survive. So Kate, if memory of my periodic table of elements serves me, carbon has the highest melting point of any element. Is that correct? It could. I don't know that fact offhand. I had, was there any, some other element you, you carrying around thinking that true about?

8:31Oof, geez. Honestly, no, not off the top of my head. Because diamond is the hardest thing. So I would believe that. Right. And then you're going to melt diamond, right? And that's whatever that takes. Right, right, right. Oh, okay. So, but if you melt diamond, then it's no longer diamond, right? That's your point. Kind of, because if you're melting it, then it's going through a phase change, right? That's what that means. And so it's going from the solid to the liquid state. And so it's no longer defined as diamond. And so diamond is a network solid, meaning that it's a bunch of carbon atoms, and they are all covalently bonded to other

9:05carbon atoms. And so when you turn that into a liquid, now we're more looking at the spaces between the carbon atoms have changed. So it's a very complex question. Is it, is it a beautiful liquid though? Is it like, does it have the bling qualities of diamond in its hard form? I love that question. You know, I've never seen liquid carbon because it is so hot and it's such high temperature, but I would love to see that. I bet it does bling. I bet it's gorgeous. But so then explain to me what these liquid crystal things were, because I'm old enough to

9:40remember the early digital watches and then liquid crystal displays. That was a selling point for them. And it was kind of cool. You'd see the, you know, the, the shadow in there, take on the shape of the, of the numbers as the time would change. Those were called liquid crystal displays. So obviously they're not diamond, but what, is that a fair question? What kind of crystal are those or were they playing loose with their language? I would say they're playing loose with the language. So to me, that feels like we have something that is, is in a crystal structure, but we've now

10:16increased the distance between the different atoms or molecules in that space, depending on what you're working with. So my, my guess is it's very loose. I'm not very familiar with liquid crystals, honestly, but. Could it be, could it be that when you set a current through it, it takes some quick configuration? Like that's almost crystal. Then you change the current, it'll, so that it's the liquid part of it is its ability to change, but while it's displaying a number, it's crystal. I love that. I mean, I know I can see, I could see that with electric. I could also see that

10:47sometimes with thermo. So I know when we have thermo properties of certain molecules and when they're hot, they're going to arrange and look in one way to our eyes, but when they're colder, they're rearranging and look different. So I could see a thermal component. I could see an electrical component for sure. But a liquid crystal to me feels a little bit like a liquid diamond. Like you're pushing two different terms together. So I, yeah, I'm not a hundred percent sure on that, but it's a good question. A liquid diamond is the same as liquid ice cubes. It's no longer an ice

11:19cube. It's just some other state, state of matter. Yes. I'm following you. Yes. Yes. It would be the same. Yes, exactly. Like liquid solid is what you were saying. Right, right, right. That's what you said. Right, right. Okay. On the subject of crystals, I just need an official chemist's

Crystal energy myths

11:35sanction of stuff I've been saying for quite some time, but I'm saying it coming from a different direction. And I want, I want your blessings for this. Okay. Okay. The people who come up to you and say, I just bought these crystals from a crystal shop. And if you rub them together, they'll, they'll bring out a crystal energy that will, that will cure your ailments. And then I say a crystal is the lowest energy state of those atoms or molecules. So you're not getting energy out of

12:08it at all. It would, it's the least effective thing you could possibly have selected from all of the universe to make that claim about its healing properties. I mean, scientifically, what you're saying is accurate. I don't want to offend any listeners that do what you are saying. I a hundred percent agree with. It is definitely the lowest energy. When we're talking about a solid, it's usually the lowest temperature, lowest pressure, like lowest energy. So from a chemistry

12:38standpoint, everything you just said tracks. No one should ever be offended by the truth. Fair. I just have some good friends that love crystals. So I try to avoid this very specific question. But wait, okay. But there's, there's a crystal like store, a couple of blocks by apartment. Okay. There is everywhere. And so what should they be selling that has more energy? Like if it has more energy than crystal, like gas. Okay. Okay. Okay. Got you. Gas.

13:14And what I also tell this and a corollary to that is when people say diamonds are forever, the proper, again, I'm seeking your blessings here. Cause you, you, the chemist, when they say diamonds are forever, what they're really saying is crystals are forever and diamonds happen to be a crystal. Cause if it, if a crystal has no lower energy state to go to, it's really stable, which is why we can dig salt out of salt mines that have been there for a million years. It's salt. Okay.

13:47There's no freshness date on what you pulled out of the mine. And it would, same would go with sugar as well. Sugar crystals. They, they, they last on the shelf, like practically forever, unless they take on smells of something, is it fair to say that sugar crystals, salt crystals and diamonds have this property in common that being crystals, they're highly stable in their crystal form. Yes. With the caveat that they have different levels of strengths. And so something that uses intermolecular forces to bond something together, which is probably like what, um, sugar is where

14:22you're using some kind of hydrogen bonding or just dispersion forces going through. Um, that's going to be your weakest ionic solids and covalent solids are going to be much stronger. So salt is an ionic solid, right? So you've got a sodium plus and a chloride plus, and it repeats over and over and over again in these beautiful cubes. Diamond is like a, no is a network solid. So it uses covalent bonds entirely. So depending on what you pick, you could argue that a covalent solid is stronger than an ionic solid. And those two are stronger than just plain old dispersion forces, but there are

14:52exceptions to all of that. And so that's just a very general trend. I had not appreciated that fact. So what you're saying, if I were to give it, give my understanding, if I'm gonna give my understanding of what you just said, uh, they're not going to spontaneously go to a lower energy state because there isn't one accessible to them. However, you could add energy to it and break apart the sugar molecule, which we do every day when you eat sugar and metabolize it, but you can eat diamonds. You're not going to metabolize the diamonds, right? Your digestive juices are not going to turn the diamond

15:26into anything else other than something that passes through your digestive tract. Right for you. Yep. Okay.

15:46Got another one for you. If we could travel faster than light, it would introduce paradoxes into the timeline of our lives. Some of them with no known way to resolve them, which might mean it's not possible to travel faster than light at all. We don't yet know. If you like that fact, you can find 4,999 more in Lost in Space. 5,000 facts to help navigate the universe. Lost in Space is now available

16:30wherever you get your books.

16:47So Nagin, you got more questions for Kate, the chemist.

Alien chemistry and periodic tables

16:51Let's, let's move over to Abington, Maryland. William Warren has this question. If we discovered life elsewhere in the universe, what chemical differences would you expect compared to life on earth and which differences would surprise you the most? Well, I was listening for two words in that question and I heard it. So in, well, actually three words in this universe, right? So if we're in this universe, I would assume that our life is going to be based on the same building blocks. We're going to have the same elements. We are going to use, if it's life, it's probably going to be carbon-based. It could be

17:24silicon-based. I've heard that argument before because that's like carbon's cousin, essentially. They're also going group four together. So they kind of behave similarly. So I could believe that. But carbon is so good at making stable molecules that I would be shocked if it wasn't carbon-based. I also would be kind of shocked if we didn't use water as the solvent. I will say the massive exception to that is where this planet is located. So if it's at different temperatures or different pressures, it might be at a spot where water is constantly in the solid form. And so we're not

17:55able to drink that. So maybe the life would have to use something else. So I would assume that the building blocks are the same. What could be different would be like the details. So I would not be surprised if their life is built on something different from our DNA and our RNA. And so maybe they use different amino acids. Maybe they're using different building blocks to get to life. So that's kind of where I land on it. What do you think, Neil? Yeah. So I'm less impressed with the silicon argument. I mean, it makes rational sense when you look at the periodic table. But we have five times

18:27or more as much carbon in the universe as silicon. So you don't need to appeal to carbon to get all the chemistry you want for your biological experiments. So that's an astrophysical result. We have to measure that to learn how much more abundant carbon is than silicon. But you're right. If we're like one of the moons of the solar system, one of the moons of Saturn, Titan, has an atmosphere. So there is atmospheric pressure. So the phase diagram of methane on that moon renders methane liquid.

19:03On Earth, it's only gaseous, right? You go there, it's cold, and there's pressure enough to make it liquid. Meanwhile, all H2O, all water, is solid. It's the boulders that are on the landscape. It's the bedrock. It's, right? So, and if we were in a volcano, the rocks would be liquid. Yes, yes. Good point. Right? Yeah. So it is fun to sort of try to break out of our box to wonder what biases we might have.

19:35But amino acids are so simple. Yeah. And we find them on meteorites. Oh my gosh. Could you make other kinds of life with amino acids that don't use DNA? Like how might you encode information? Have you guys thought about that? You guys on your side of the fence? I haven't. I can't even wrap my head around that. I don't like that question at all. I don't know what they do. Right. Because, okay, you're not supposed to say you don't like the question.

20:08That's not allowed. Your question. I don't like that one. Like what would they use instead of, you know, our adenine or our guanine? Like, I don't know. I don't know what they'd use. It would be fascinating to find out. No, I'm saying give them the amino acids because you get that for free because nature is making that in asteroids that land on planetary surfaces. So you start with that. But somehow in there, we came up with, we, our biological chemical ancestry came up with DNA to encode our, our identity and our properties and how we function. And so I, I, one of the biggest

20:46questions I want to know, want answered is, is DNA inevitable wherever you'd find life in the universe? That would just be fun to know. It would be so fun. It would be so fun to know the answer to it and know exactly how it operates and if it operates the same way with RNA, if they have the same thing. So I would love to find that out. So hopefully we both live long enough so that we can discover that answer. There's actually a question from listeners that's like related to this one that maybe you guys could talk about both of them in the same breath. From, from Lenny

21:17Ducano, Romanian writing from Los Angeles. He writes, if intelligent aliens develop their own science, would their periodic table look exactly like ours? Or is there any chance chemistry could be organized in a completely different way? Can you think of a different organization of the periodic table that might be preferred to an alien? Well, there's, there's tons of different versions out there. It just, we stick with the ones we use that Mendeleev created because it works so well and you can get so much information with that basic structure. I mean, if we go all the way back to

21:50when he first created the periodic table, his was so good because he realized that there were two elements missing. So gallium and germanium weren't there, but he was like, I'm looking at all these pieces. It to him looked like there were two puzzle pieces missing. So he left spots for that. And so later, years later, when we discovered gallium and germanium, he was able to pop them right into the periodic table because it followed the patterns. It followed the chemical, the predicted chemical behavior, but you could organize it in different ways. Right now we use atomic mass. We use atomic number. We even look at valence electrons, but you could do nuclear stability. You could do

22:23conductivity. You could do abundance of the universe. So there's a number of different ways you could organize it. It just matters like how you want to use that table. So right now, the one that we use, the one that everyone has seen is the easiest to interpret and grab very important information off of for a chemist. We care about valence electrons. And that's one of the easiest things you can see from that arrangement of atoms. So here, here's my critique of that. So let's say you, you, you order them by, uh, give me one of the ways you said they might order it. Maybe like nuclear stability,

22:54abundance in the universe. That's, that's a good one. Abundance in the universe. Then it's not a table. It's just a list. Good point. See? Yeah. And same with, um, uh, nuclear stability. There's a bunch of them that have completely stable nuclei. They'd just be in one little group and others are unstable at different rates. So then it would, it would once again, just be like a sequence. So, so maybe. So this is how we'd know we're better than aliens, I think. Exactly. Exactly.

23:26Even though they got here in a spaceship and we haven't left low earth orbit in a zillion years, we got a better periodic table than that. I look forward to that bragging right from the alien cubs. I love it. I want to watch that conversation.

23:42So Kate, is it out of the chemists, uh, realm of possibility to think of liquids at very different temperatures from room temperature that could serve as solvents or as a means of moving nutrients? Because I w I was only partly joking when you look at very high temperatures where our rocks become liquid, right? On Titan, our liquids become its solids. We have

24:13rocks of water and they're probably wondering, it's so hot on earth. The rocks have melted and they drink the melted rocks. I mean, picture, picture this, this scenario. So is there enough active chemistry in these different regimes of temperature to imagine a whole biota? I think so. To me, that comes down to a solubility piece, right? So like, look at our blood right now. We have things that move through in either the water side or like the fat side of things, right? And so if we

24:47have, if they could figure out something in that realm where we could put our molecules into some solvent that could essentially dissolve both in the fatty side and the non-fatty, so hydrophilic and hydrophobic essentially is what I'm kind of getting at, then maybe, maybe there's a way to move the ingredients or the molecules that are needed for their form of life just by finding a specific solvent that has really fun polar and non-polar properties. So maybe there's something in that space. To carry it along. To carry it along in a circulation kind of thing. Because we can ask, at least on Saturn's moon Titan, maybe life doesn't need liquid water as we've

25:24been presuming. Maybe it just needs a liquid and there you have methane as a liquid. And methane is also highly reactive with oxygen, highly combustive. So maybe the life form figures out a way to drink it, but then pull some away to get energy out of it, right? When it, if we can find some oxygen. That's a wild concept. Yeah. Yeah. I mean, what are we to them, right? We're wild if they're figured out a way to do it. That is such a wild concept. So, okay. So methane is something that is non-polar. So we would need a

25:58non-polar solvent in that, which is totally fine. I'm sure they could find a non-polar solvent there. But the fire piece is interesting because there's a fire triangle. And so methane would be the fuel source. Oxygen would be oxygen, but then they would need a spark. So if there's a way to make it that there's no spark on this other planet, then we could absolutely somehow find a way to get oxygen in the liquid methane to get it something. I mean, this feels like now we're really doing what if, what if, what if, but maybe.

Fire triangles and explosions

26:23Wait, wait. There's something called a fire triangle? Really? Oh my gosh, Neil. Yes. Welcome to fire 101. So you have three different things in a triangle. And in order to have a fire, you have to have all three. You need a source of fuel, you need oxygen, and you need a spark, like a heat source, an ignition source. And if you take away one of them at all, then you will not be able to have a fire. Okay. So wait a minute. So when I had a cap gun as a kid, okay, there's oxygen in the air. I've got little mini pads of gunpowder and I just smack it with a hammer. So there's no spark. I didn't,

26:54I didn't give it a spark. Hammer, that force, that ignition, that's all it could take. That's all it would need. So a source of energy. Yes. Not specifically a spark. I'll take that. I'll take that. Yeah. Okay. Usually, usually it is a spark, but yeah, a source of energy. I'm coming to it as a physicist, you know, a spark has energy. So if I equate, if I have an equivalent amount of energy, but it's not a spark, will it have the same effect kind of thing? And I would say yes, from a chemist standpoint, what you're doing is breaking bonds and then making new bonds. You're

27:24rearranging atoms. So to do that, you have to break a molecule, like you have to break a molecule and to do that, you need energy. So I'm happy with that argument. So you need energy to start the energy into motion because when you, when you break those molecules, it's releasing energy, right? That's how you get the explosion. Got it. Got it. Fire triangle. That's cool. Fire triangle. And then there's the, oh geez, I hope I can get this right. There's a Pentagon when you get to a dust explosion. So like if you've ever had like see or heard about a sugar factory explode, you take the fire triangle and then you add two corners to it to make the Pentagon. And so you have from the

27:58triangle fuel, oxygen, and then the spark or the energy source. And then you also need a confined area. So think like a, like a silo, right? And then you also need the fuel to be in a particulate matter. So if you have all five of those corners, then you get a huge explosion that kills people. It's really dangerous, but there's the Pentagon stretch from the triangle. So when I was growing up, there was this spate of silo explosions and I thought it was maybe a methane thing from the decomposing plants, but they, those explosions, I guess would have been, did they achieve the pentagram?

28:34Could have, could have, if it like the sugar explosions, um, I think Imperial sugar had a really, really big explosion like that. And it's because they have all that dust particles that build up. And then it just takes one spark to have your first explosion. And then it actually triggers a second explosion. And the second explosion is the big one. That's the dangerous one. Gosh, this is making me look at sugar and like a completely different way. Like it's makes you fat and it can explode. Yes. Yes. What would have to happen on Titan is there would have to be some

29:06systematic source of what, what is enabling us to generate energy within our bodies without some gnomes setting off sparks? We have a source of fuel called ATP. And so that's basically our chemical energy in our body. And so we make it, we break it, we use it, we're constantly regenerating it. And so that's our source of energy. So we have chemicals that break it to release the energy. So the chemical is the spark. We have specific chemicals, molecules, got it, got it, got it, got it. Molecular

29:40sparks. Okay, cool. Molecular sparks. Cause all of our energy is stored within the bonds between atoms. And so when you separate atoms and then you rearrange atoms, it's all about transitioning energy. And so, I mean, it's, it's, it's all chemistry at the end, but I don't want to say that to you because you're going to believe it's physics or astronomy. Meet me outside. We'll settle it in the playground. Got it. We'll meet you at 30 Rock. Oh guys, the gloves are coming off. Okay. Yeah. I've said this and people don't want, I mean, they've never thought about it,

30:12but I think it's just bluntly true. If we didn't have energy stored in the molecules of our body, you could not be cremated. I mean, I guess so. Right. We're the fuel source. Yeah. Yeah. That's what's burning, right? That's why anything burns. Cause the, the, if, and if something doesn't burn, it's cause there's no energy in its molecules to burn. You can't burn diamonds. Neil, why'd you have to make it so weird? I'm just saying. It's a cremation. Oh my God.

30:44Well, and all I can think about is our bodies are primarily water. So we must be dehydrated first. And then once that water's out, then the rest of it is the fuel source. So yeah, I can, I can absolutely see that. But ew. Those reports of spontaneous combustion, can't have been as described. Cause they said a person was sitting in their chair, usually an overweight person. And then the fat ignited and it just systematically burned them. It's like, no, you have, it's why you can boil water in a paper cup. Have you ever tried that,

31:16Nagin? Boiling water in a paper cup? Yeah. Have you ever tried that? I, I can't say that I have. Okay. It's just real dangerous. I haven't, I haven't done that either. Wait, you tell us. What happens? Okay. So you get a paper cup and so I've got to be careful about it because most paper cups are wax covered, but that's okay. But they also often have a rim in the bottom. Okay. And that rim, which it stands on is not touching water when the water is in the cup.

31:49So you have to just be careful how you do this. And so anyhow, it works best with like a Bunsen burner. Remember those from chemistry class, Nagin, because it's a very localized flame or you can take a, take a lighter. Anyhow, you put water in a paper cup and put the flame at the bottom of the cup. You can also put it at the side, but the bottom is better. Okay. And just let it sit there. You'll say, but isn't it going to burn the paper? No, because the paper is the temperature of the water. That's okay. So you're not going to burn the paper cup until you evaporate the water down

32:25to the level of the flame. Then the temperature of the paper can go up to the temperature of the flame. Now, if the paper is really thick, you'll start ablating the outer fibers of the paper, but the innermost fibers that are touching the water, you're not, they're not getting any hotter than the water itself. Kate, you should have done this for COVID. I should have. Wait, Kate, are you, do you have to have a disclaimer in your book? If your house burns down, have you been sued yet?

32:57Not yet. Knock on wood. Don't even put that out there. I know. Okay. Sorry. Sorry. Sorry. No, but I do have disclaimers for messy factors in there for my, for the parents. Cause I know some people don't want like really messy experiments. So that I do have, but I don't have anything super dangerous, especially in the cooking one. That's, that's great. Yeah. Okay. Okay. Cool.

Paint can and dry ice experiments

33:29I'm Nicholas Costella and I'm a proud supporter of StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

33:41So Nagin, what more do you have for us? Last time you were on StarTalk, uh, you suggested that my daughters and I do an exploding paint can experiment. Well, it was the bomb. Amelia and Olivia decided to, Amelia and Olivia decided to add glitter and purple food coloring and called it unicorn diarrhea. Yeah. Now that they're a little older, let's kick it up a notch. Give me your messiest for a five-year-old

34:12and a nine-year-old. Wait, wait, back up. Remind, remind me of this exploding paint can experiment. Jeez. I hope I gave safety tips for that. Cause that one can be a little bit, uh, dicey, but essentially what you do is you put like an inch of baking soda in the bottom of an empty paint can. Then in a cup, like a plastic cup, you'll put maybe a cup of vinegar and then nestle that plastic cup into the baking soda, kind of like a sandcastle, if that makes sense. And then you're going to put the lid on top of the paint can and then hammer it shut. And it needs to be completely sealed.

34:45There can't be any gaps for a gas to get out or anything. And then what you do is get your face very far back away from it, shake it up, slam it down on the table and the lid will pop up. And if you do it with a little one, it will go like a foot or so in the air. If you do like a typical paint can, you can get it five, 10 feet in the air. So it's really high. It's a fun one. Wow. So, so how much baking soda for a normal size? Yeah. Just like an inch. That's a lot of it. No, I'm not, you know, baking soda is expensive. I'm not paying. Everything else I do. The paint can is going to be more expensive than the baking soda and the

35:20vinegar. So, well, we presume you've used up all the paint, which hardly anyone ever does. Okay. I always buy a new paint can for these. I don't use ones that have paint in them already, which probably you should do to anybody at home. Oh, you buy an empty paint can. So the gallon size one or the littler ones that they use for touch-ups? I've done both, but I like the gallon size ones because those are so big and they give a much bigger explosion. And why would you do it? Wow. Wow. So, so the chemical reaction overcomes the physical, the friction between the lid of

35:52the can and the can itself. Yep. So it's vinegar and baking soda. So an acid-based neutralization, very standard, releases carbon dioxide gas. So much gas is released that it basically like pounds on that lid. And then after enough collisions, the lid just pops right up because it's not screwed on, right? It's just like shoved in there a little bit. It's nightly placed with tension. And so the force of the chemical equation releases so much pressure that it just flings the lid off the top. So it's super fun. Is it loud? Like, is it scary? The explosion?

36:23No. No. It's like a boop. Okay. But it just, it looks scary because it goes, the lid goes really high in the air. And then this like goop, think, think vinegar, but with baking soda goop. And I always add food coloring in there. So that goes everywhere. So the kids will scream. I always act scared because then it's all fun. Yeah, yeah, yeah. It's more fun. Yeah, yeah, yeah, yeah. So Kate, in that case, Alyssa, was that her name? Yeah, Alyssa. Alyssa, you can add other ingredients and not disrupt that chemical reaction between the baking soda and the vinegar?

36:55Yeah, glitter and food coloring is as far as I'd take it. Don't add anything else because you don't know, I don't know what else you're going to add in there. But yes, food coloring, glitter, make it lots of fun. But if you want like a new experiment, do you think she wants a new experiment for her kids? Yeah, because the kids are older now. Yeah, okay. Yeah, they're five and nine. Take it up a notch. Make it more dangerous. Well, all right then. I had one, but now I'm going to switch it because you said dangerous. So again, use safety gear, everything I'm about to say, make sure you wear cryogenic gloves. But one thing that could be really fun is get like one of those kiddie pools, one of those like cheap

37:28little pools, fill it with water, and then grab a bunch of dry ice, which you can get from a local grocery store, throw it right in the center. But before you do that, before you add the dry ice, set up four to five, maybe even six box fans around the side and all have the air flowing in one direction. So you can create essentially a vortex or a tornado. So when you throw the dry ice in the center, you'll get this really cool white tornado that will form and it will just whip around and you'll have to play with the box fans to get the right position. But that's a really fun one to do. But please, please, please, cryogenic gloves, goggles, lab coat, the whole thing if you're playing with

37:59dry ice. As one has cryogenic gloves, of course. Is that, can you also get those from the grocery store? Okay, maybe use like work gloves like you get from like a Home Depot or Menards or something like that. Just like those thick, thick gloves. And the box fans have to be like the same exact size or whatever for the thing to have the effect? Yes. Same exact box fans, but they're angled. So like you wouldn't have them think perpendicular to the pool, but angled just a little bit. So maybe we're talking like a 75 degree angle, something like that. And then all around. So it whips around in

38:32a circle. It's so cool. People have to know that perpendicular is 90, just to be clear. Sorry. Thank you. So would three fans do it? Three fans might do that. No, no. I would do four to six. Three is not going to be enough. Who has six box fans? I know, but you would have to invest in this, but it's not like it'd go bad. You'd be able to do this over and over again. A box fan for every room. Yeah. And we all love tornadoes for sure. So tell us about solid CO2. Solid CO2 is dry ice. It is super fun. You can

39:06make things called dry ice bubbles just by using a little soap and putting them over, over the top. If you put dry ice in water and then put soap over the top of the container, you can get this really beautiful bubble. Liquid soap. Yeah. Liquid soap. Liquid soap on the outside of the container. Like if you're using a mason jar, okay, you can put water in the center, throw dry ice in there and then put liquid soap on the lid, that lip of it. And then you'd get this really beautiful dry ice bubble, which is, it looks like a bubble, but it has white gas in the inside. That's your water vapor forming from the sublimation process. It is super, super fun. I love, love that one. Let's see. What else can I talk

39:39about dry ice? Oh, just carbon dioxide in general. Most people think that when they exhale, they're exhaling 100% carbon dioxide. That is false. Do you all know the percentage? No. Let me guess. I don't know. 10%? Oh, 4%. 4%. When you exhale, it's 4% carbon dioxide. And so a lot of people think that it's 100%. That is false. CPR would not work. If we exhaled 100% carbon dioxide, there's some oxygen in there, a lot of nitrogen, but carbon dioxide is everywhere. It's also what's causing climate change. So we really need to fix that and get the carbon dioxide out of the atmosphere. So there's my

40:12riff on CO2. Is that enough? I love it. I love it. And just to be clear, that CO2 presumably was not made from fossil fuels. They probably pulled it out of the atmosphere anyway. So you're not adding to the net CO2 in the atmosphere by doing the chemist experiment. Well, I mean, if you're studying something on fire and I told you to do that, you are adding to the CO2 in the atmosphere, but playing with dry ice, no, not so much. All right. Kate, I think that's all the time we have. Oh my gosh. It went by so fast. Oh my gosh. It did. We had so many more questions

40:47that people want to know. And why does today's show always get you? We want you too. Okay. Next time. Next time. So sorry about that. I'll reach out next time. Next time you come through town. When we have a booking agent for this, we will land in that circle. Perfect. Love it. And congratulations on your professorship. We need more of those. We need one of those in every university. And maybe that would make a dent in the science literacy of the world, which is so much

41:19a victim of its own ignorance when we have to make important cultural, political, economic decisions that hinge on how much science, you know. So Kate, keep up the good work out there. Thank you. Can I plug the fact that I'm going on tour in the fall? And if you guys want to know more about it. Yeah, it's a stage show. So I'm going to a bunch of different performing arts centers. If you want to know more, go to my Instagram and TikTok at Kate the Chemist, and you'll be able to see all the dates when we finally able to announce that, but just put it in your calendar. We're coming to hopefully to a city near you. Excellent. Very excellent. Totally. We'll find you. Okay.

41:52Yay. So, Nagin, you are host of Fake the Nation? Yes. I'm host of Fake the Nation. Find me there. You can find me on Wait, Wait, Don't Tell Me on NPR with more coming. Excellent. Well, I love Wait, Wait. We all love Wait, Wait, Don't Tell Me because it's so smart and funny and topical, all of the above. So keep up the good work there. Yeah. All right. I am Neil deGrasse Tyson. You're a personal astrophysicist. This is the Kate the Chemist edition of Cosmic Queries on StarTalk. As always, I bid you to keep looking up.

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