SciShow Tangents - Subatomic

Episode Date: February 18, 2020

Things get a little weird this episode, and by ‘little’ I mean very little! One thing I learned in this episode is that everything in the universe is touching each other, yet the particles in your body never truly touch! Mama Mia! Well anyway, I hope you enjoy it! Thanks for listening!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Stefan: @itsmestefanchin Ceri: @ceriley Sam: @slamschultz Hank: @hankgreenIf you want to learn more about any of our main topics, check out these links:[Truth or Fail]https://history.fnal.gov/felicia.html#Timehttps://history.fnal.gov/meson.htmlpictures: https://www.atlasobscura.com/articles/felicia-ferret-particle-accelerator-fermilabhttps://www.smithsonianmag.com/arts-culture/stocking-series-part-1-wartime-rationing-and-nylon-riots-25391066/[Fact Off]Surface plasmon resonancehttps://www.nist.gov/news-events/news/2016/12/nist-device-detecting-subatomic-scale-motion-has-potential-roboticshttps://www.nature.com/articles/ncomms13746Dark matter supercold water[Ask the Science Couch]Do atoms touch?https://www.sciencealert.com/99-9999999-of-your-body-is-empty-spacehttps://wtamu.edu/~cbaird/sq/2013/04/16/do-atoms-ever-actually-touch-each-other/https://www.britannica.com/science/Pauli-exclusion-principlehttp://hyperphysics.phy-astr.gsu.edu/hbase/pauli.htmlhttps://www.britannica.com/science/fermionhttps://www.pnas.org/content/114/23/5766[Butt One More Thing]Proton-powered poopshttps://www.sciencedaily.com/releases/2008/01/080109104251.htmhttps://www.sciencedirect.com/science/article/pii/S0092867407014791

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. And this week, as always, I am joined by Stefan Chen. Every time you say my name a little bit more extremely, and one time you're going to go beyond. It's going to go too far? Yeah. I'm going to hurt your voice.

I got a little eye twitch just now. Be careful. What's your tag on? Poopy diaper? Oh, no. Can I bring that? We were just talking about how we don't like poopy diaper as a phrase. Sam Schultz is also here. Hello.

What's your tagline? Peepy diaper. This is the better kind. Sari Riley. Hi. Hello. What's your tagline? Soda sculpture.

Diaper. Just add diaper on the end of it. No. And I'm Hank Green, and my tagline is peepee mountain. Soda sculpture. Diaper. Just add diaper on the end of it. No. And I'm Hank Green, and my tagline is pee-pee mountain. Every week here at SciShow Tangents, we get together to try to one-up a maze and delight each other with science facts. We're playing for glory, and we're also keeping score and awarding sandbox from week to week. We do everything we can to stay on topic, but actually I lied about that. So if you go on a tangent and the rest of the team deems

it unworthy, you can be Dr. Hank Buck. And now, as always, we introduce this week's topic with a traditional science poem this week from me. The word atom has a clear meaning. Indivisible, no in-betweening. But then, oh, well, shit, the atom was split. I find that a little demeaning. Well, shit, the atom was split. I find that a little demeaning. We worked so darn hard to define it, so immutable you cannot refine it. But down at the hearticle, there are more particles. Subatomic is how we assign it.

Hearticle? Look, there are not any words that rhyme with particle and I wanted one and hearticle felt real to me it felt real it's like the heart ventricle it's a part of a heart yeah I would not have been surprised

if you busted out a guitar and just sang your I thought about it strange charm song yes I thought about strange charm but I felt like that would be cheating

and you wouldn't give me a point for it because you've already written it it wasn't special for this I think it would've been okay the fans give me a point for it. Because you've already written it. It wasn't special for this. I think it would have been okay. The fans would have gone crazy for it. Ah, shit.

I didn't do that. And our topic is subatomic particles. And I guess that's a fairly easy thing to define. Well, physicists have talked a lot about it. Yes. And it's any particle that's smaller than an atom. Wait, it doesn't have to be part of an atom feels like a subatomic particle has to no i guess it doesn't i don't think so i

think it's just like just smaller than an atom smaller than that but i think the only things that are smaller than an atom are the particles that we've identified or and the ones that we've on are unidentified yeah there are particles that are not in atoms. So, atoms are made of protons, neutrons, and electrons. Okay, yes. And then smaller than that,

you have things like quarks. Yes. Are there subatomic particles other than photons that last for significant amounts of time that aren't part of an atom? Yeah.

Neutrinos, they're always chilling out.'re around they last is there one in this room right oh yeah yeah they don't touch us though that's good they go right through are they like in a different plane of existence no they just are so they just don't interact with matter very much okay we're going to talk about this later but really nothing's touching each other ever. We're just all like probability clouds. Oh, that old chestnut. Chestnuts also don't touch things.

Yeah. Or themselves, really. Yeah, it's basically very, very small things like quantum. Whenever you say something's quantum, like an ant man when they say, we're going quantum. They just mean small, like classical physics stops making sense. And then you have to start using quantum physics to explain it. It's a different math. Deboki shared a tweet with me that said, petition to replace quantum with Lil.

That would be helpful for me. Yeah, Lil Mechan me. Lil mechanics. Lil mechanics. That actually is very helpful. Yeah, that'd be way better. So are there any,

do you have any meanings behind any of these words? I looked up Adam, but Hank said it in his poem. It's from Greek Atomos, which is

uncut, unhewn, indivisible. But they weren't talking about atoms as we understand them. No, but they had some thought that there must be something there as a conversation. If you cut something enough times, eventually do you get to something you can't cut? Right.

Kind of like high person conversation. Yeah. Cool. Yeah, no, they probably have some kind of leaf that they licked. Or chewing on. Yeah. Okay. No, they probably have some kind of leaf that they licked.

Or chewed on. Yeah. Okay. And then it like became used in a scientific sense from like the 1800s, I think, to refer to atomic. This is where like science and philosophy were so intertwined because people were just asking big questions about the universe and like yelling out answers. And some of them were right. And it's wild. Like back then, people would like yell out, Adams! And it would be like, now we're like, what a genius! But he just happened to were right. And it's wild. Like back then, people would like yell out Adams. And it would be like, now we're like, what a genius.

But he just happened to be right. The person arguing had all of the same evidence and all of the same reasons. Like there wasn't any good reasons to believe Adams were a thing. It just turned out they were. So there might be something I've said that will turn out to be right in the future. And people think I'm a genius? No, not anymore. Oh.

Yeah, that's only from back when we used to give people a lot of credit for their weird ideas because they were rich and powerful. Okay, unless the world ends and all that's left of media is this podcast, then we'll start all over again. Yeah, there are worse podcasts to rebuild human

knowledge and institutions from than this one. That's our blurb. Good blurb, everybody. Thanks, Sari. And now it's time for more Sari because Sari's doing true science. She's brought three science facts

for our education and enjoyment, but only one of those facts is real. We have to decide which fact is the true one. If we get it right, you get a sandbuck. If you don't, then you get the sandbuck. Sari, what are your facts? The Fermi National Accelerator Laboratory, called NAL to start, but now Fermilab, is a particle physics research lab in the United States that's been open since 1967.

The very basic layout, to my understanding, of early Fermilab particle accelerators is pipes with hundreds of large, like 20 feet long magnets along the length of them that help guide and focus the particle beam. But in early years, they ran into some problems with this construction. When these 300 foot-ish long pipes are cut, there are tiny metal slivers and dust left behind that can interfere with subatomic particle travel and the magnetism because they're metal slivers. So scientists needed to find a way to clean out these pipes and do it relatively cheap. An engineer named Robert Sheldon came up with an unconventional solution. What is it? One,

tying together a bunch of nylon stockings, threading them through the pipe and swirling the fabric around. Two, making slime from borax glue and warm water that's sticky enough to grab the metal but flowy enough to pour through the pipes a few times. Or three, using a ferret to pull a string through the pipes that they attached a fluffy swab to and pulled back through. Wait, wait, can't they just flush it with water? How do they pull it back?

What do they pull back through? A string. So they like make a ferret run through, draw a string through, and then they attach something to the end and pull it back through. So they pull the ferret back through?

They're not cleaning it with the ferret. They're not cleaning it with the ferret. The ferret is the... Is that where ferry comes from? Uh-huh. Comes from ferret.

The cleaning apparatus. Just like walks it through and then you got to... Because ferrets are straight dirty. You don't want a ferret to be cleaning and then you gotta cause ferrets are straight dirty you don't want a ferret to be cleaning stuff with a seum ferret

maybe it's a clean ferret maybe it's a very tidy ferret I guess you make like soft pieces of clothing out of ferrets yeah they're little swiffers

yeah yeah okay pouring slime I'm into it like the kind of slime people make on YouTube yeah but like way before it became a YouTube thing

it was a science thing. So you're saying this was before YouTube? Yes. You know, Fermilab? Before YouTube. How long are these pipes? Do you have any idea? Around 300 feet.

And how far can a ferret run? That I can't answer. How big are these pipes? There are some measurements, I think, that I read that they were like a foot in diameter, but they can get as small as like a couple inches. Okay. These are like particle accelerators. Yeah, particles are going through them.

Yeah, so they need to be really, really clean so that when they assemble it together and they put magnets on the outside, the stream of very subatomic particles can... They can be pinging off the little pieces of metal floating around. Yeah, exactly. So we've got tying together a bunch of nylon stockings, threading them through the pipe,

and then swirling it around. Two, making slime from borax, glue, and warm water to pour through there and pick up all the stuff. Or three, run a ferret through there so he pulls a string, and then you can grab a fluffy swab and yank it through the whole thing. Because you can't turn it up on its end and, like, throw a rock down.

No. So they could tilt them up. And so that's, like, how they would get, hypothetically, all the things in. So it's, like, gravity helps the ferret go down, potentially. Or the slime. Slime or the stockings. Okay. So if you stick nylon in there, that feels like it's going to leave some sort of fibers.

I don't know. Just let me have this. Nylon doesn't leave fibers. That's like why it was such an important technology. And like, because unlike other stockings, it like didn't rip. It didn't like shred really. It just stayed.

It could stretch, but stay tight. Well, I don't know. The ferret does seem dirty, though. That seems like it would leave something behind. Yeah, it does seem like it could cause some extra problems. Yeah, what if he pooped in there? Yeah, he could leave a poopy diaper. Yeah.

Oh, they probably put a diaper on the ferret. Well, now they all seem plausible. I'm going to go with the slime one. Slime for Stefan. I'm going ferret with the slime one. Slime for Stefan. I'm going ferret because I want him to be wearing a diaper. I have to get every point this episode, and you have to get no extra points this episode for me to tie you. All right.

Well, I've already got a point because I did the poem. I know. I took that into account beforehand. I'm going to go with whatever one is left. Oh, okay. What is it? The nylon stocking. Yeah. Does that sound good? Do you actually want it or with whatever one is left. Oh, okay. What is it? The nylon stocking. Yeah. Does that sound good? Do you actually want it

or do you want to... Oh, no. Do you want to hurt Sari more than you want to hurt me? Yeah. Yeah. She's more in the lead. I like the ferret. I'm going with the ferret. Okay, two ferrets. Ferret is correct. Yay! Oh, sorry, Sari.

No, that's okay. I switched him. Yeah, you're never going to get mad at me. is correct. Oh, sorry, Sari. I switched him. Yeah. It's you're never going to get mad at me. Why? I just you're too nice. Oh, we can get mad at you. Do you want us to try?

Oh, you can get mad at me. I'm less likely to get mad at you than Sari is. I feel like you get ornery faster than I do. Totally do. That's what the fuck? I get vengeful. I'm not saying I don't like it. This is a part of me You're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like, you're just like Yeah, she did. Oh my God. And it was just one ferret?

They only had one ferret working? Yeah. Her name was Felicia. She was about 15 inches long. She cost $35. Did they go to the store and get a Felicia just for this? They did, but not a store like some sort of ferret ranch. That's a store. Yeah, that's a kind of a store.

Special delivery from the Wild Game and Fur Farm in Minnesota. Oh, so Felicia had a... Bad future coming. Yeah, potentially. Had a better life than she otherwise would have had. Yeah. They didn't ever accelerate particles into her. No.

They trained her very gently, started her on shorter tubes to be like, run through this tube. They fitted her, outfitted her with a small leather harness and a diaper to collect her poop and attached to a string so that when she would run through the tube, she could like unhook, they could unhook the string and then attach a cleaning swab, which as far as I could tell is like a brush or a cloth with some sort of cleaning fluid on it. And then they'd pull that through and pick up a bunch of dust and metal filings. And do it again and again, however many times you need. Felicia's here for you. Does she just go into the darkness?

I guess ferrets don't go into the dark. She just ran into the darkness. And part of why they chose ferrets is because ferrets love tunnels. She was a little bit nervous at first because it's just a 300-foot-long tunnel. And so by training with small, dark tunnels, she got more comfortable with it. But they chose ferrets because they chase after things in tunnels all the time. This is a picture of her. She's very cute.

Oh! Did they keep her around? She's really cute. Well, I mean, once you train a ferret to clean a particle accelerator. But once they're clean, what are you going to do with a ferret? Maybe it gets dusty in there. You got to do it again. Okay.

So they kept her around for a little bit, and apparently all the engineers loved her, and they fed her meat. She liked ground beef i think yeah it sounds like ferret food but but oh this is not because of them i don't think but around 1972 someone else had created a magnetic ferret basically they called it a magnetic ferret modeled after felicia but it did not look like a robot it was just like one of those tubes you stick in a drain pipe and swirl around so it was like that with magnets on it that they pushed through with compressed air to basically do the same thing as she did so she was like a temporary solution so then she retired and she was gonna be like live a cushy life but then like a couple months after she retired she like went to an emergency

vet visit and had an intestinal abscess and died and everyone was really sad she couldn't enjoy her retirement was there slime truth or were you just talking about slime from youtube yeah i feel like you were just talking about i just made it up. I talked about nylon because the history of nylon, very interesting. It was created, I think, initially just by a material scientist who then realized it could be marketed to women for stockings instead of silk. But then during one of the world wars, they realized that nylon could also be used for really important like other fabric applications like parachutes. And so then they basically banned stockings from being sold and recalled all of them. And so everyone was in like a stocking frenzy. It's like, ah, I need my tights.

Well, thanks to Robert Sheldon for bringing us Felicia. Next up, we're going to have a short break and then it'll be time for the Fact Off. We're back, everybody. Sam Buck totals. Sari, you got one. Sam, youals. Sari, you got one. Sam, you got one. Stephanie, you got none. I am in the lead with two.

Good job. Thanks. I appreciate that. Is Stephanie the least likely to get mad at you? Am I the least likely to get mad in general? Yeah, I don't think I've ever seen Stephanie mad. Yeah, this is like what we were talking about where you don't even have a resting bitch face.

No. You just a resting bitch face. No. Like you just have a friendly face. I feel like I do because I have a very blank face sometimes. And I feel like a bitch. I feel like I've seen Stefan in some situations where he should be mad but wasn't. I think you're less likely to become. I'm a chill dude. You're a California guy, skateboarding around, surfing the waves.

So now it is time for the fact op. Two panelists have brought science facts to present to the others in an attempt to blow their minds. The presentees each have a Sandbuck to award to the fact that we like the most. Sari and I have the Sandbucks to award. It will be Sam versus Stefan presenting your facts. And to decide who goes first, you have to tell me each how many flavors of lepton there are. Balls.

Sam, how many flavors of leptons are there? 4,000. 4,000. Sam went with 4,000. I'm going to say six. Closer. I don't know, but I know that it's closer to six than 4,000. 4,000. Same one with 4,000. I'm going to say six. Closer. I don't know, but I know that it's closer to six than 4,000. The answer is six.

Stefan got it exactly. A good half does. Did you know that? I have heard the number six before. Oh. I thought it might be associated with this. So I guess, Stefan, you want to go first? Oh, sure.

I'll go first. To make sense of this, I have to explain something called surface plasmon resonance. I don't know what that is. So basically, you have a gold sheet. And if you shine the right frequency of laser on that sheet at the right angle, the light excites the electrons on the surface of the gold and they resonate in waves. And so those waves are the plasmons. If you're trying to visualize it, you can think of it as like the surface of the gold. You've got sort of like a guitar string that's vibrating in slow motion.

You can kind of see the waves happening. And these plasmon waves are sensitive to the environment around them. And so one way to measure how two molecules are interacting is if you attach a bunch of one molecule to the gold sheet and then flow a bunch of the other molecule past it, when they bind, they affect the frequency of those waves, which changes how much of the laser is absorbed. And so by measuring how much of the laser light is being reflected, you can get a sense of what's happening with the molecules. Like how frequently they're bonded and unbonded. I'm pretty sure I've simplified some of this, but that's basically what's supposed to happen.

You shine a laser at something, it tells and using cool particle physics, it tells you things about molecular interactions between two chemicals. Yes, and that's surface plasma on resonance. And so, there's this paper from the National Institute of Standards and Technology, where they take

a gold sheet, and then they have this... They describe it as diving boards that are like on top of it and on the bottom of the diving boards are little gold nanoparticles so you have gold nanoparticle right above this gold sheet and like it's arranged so that there is a tiny space between them that space is so small that a laser light couldn't actually penetrate it so they couldn't measure so you can't measure it because you need the light to bounce off it to measure it. But what they can do is use this similar technique where you're bouncing the light off of the

gold nanoparticle. So you get these plasmon waves. And then if the diving board moves, if the gap changes width, then that changes the frequency of those waves and then changes the absorption of light. And so then you can measure it. Why do you want to do that? So they describe it as very similar to the devices that detect motion and orientation

in your phone. So like if you had this little chip with all these diving boards on it and these gold nanoparticles in your phone and you like wiggle your phone around, the diving boards are wiggling. And so you can measure these gap changes. Obviously, we already have smartphones that detect those things, but this would be like the next level of like miniaturizing those. Right. Smaller, more sensitive.

Yeah. Maybe less energy intense to use. Yeah. And I guess it's also similar to the things that they use for airbags, like detecting when those should go off and stuff like that. It's like the tiniest accelerometer. When you are looking for something like what you're describing, do you theorize that it exists and then figure out a way to look for if it exists? Like a wave, the wave. How do they know the wave's going to be there?

It's kind of a coin toss. It could either be that they did math first and they were like, I wonder if we could actually show this in the lab. Or they had some gold foil and they shot a laser at it and they were like, this is weird. Okay. Why is it changing? Why is the absorption changing? And they were like, oh, it's because there's some oxygen reacting with oxygen making ozone on the surface of the gold or something. People are smart.

They are so smart. All right. That was weird. Good diving board, Stefan. All right. So for my thing to make sense, I have to explain something called YouTube. So way back in 2011, which is like a million years ago in Internet time, there were a number of videos showing off a very neat home experiment

where people were cooling purified water in really clean containers down past the freezing point, but the water would not freeze. It would stay liquid. And that's because ice needs a nucleation site to form, which is either an impurity in the water or the water jostling around and clicking all the whatever water's made out of into ice form. Is that about right?

Molecules. Water molecules. Oh, that's an important word later in my thing. Remember that. First, let's explain molecules. The science couch has got you. They're at a level that I understand again. Yeah, this is good.

Yeah, super cooling, I'm all there for. So then the experimenter would shake the bottle up and the water would basically freeze in front of your very eyes. Very cool. We even made a video about it in 2014, which was really helpful to me. It said the word molecules in it for sure. So inspired by these videos, last year a team of scientists studying super cold water figured out, I think kind of accidentally,

that it doesn't require something as dramatic as being shaken up to freeze, but can be triggered by certain kinds of uncharged subatomic particles passing through it. So using this discovery, they made a new kind of particle detector called a snowball chamber. It is basically like a chamber of super cooled water

sitting like totally away from the world. And then when a subatomic particle passes through it, it freezes. Nice. So it's only affected by uncharged particles. And I had to email the guy who wrote the paper to figure out why that was. His name is Matthew Zadagus. And he told me that, quote, Charged particles interact with the electrons and lose their energy spread out over a greater distance.

This is called DE over DX. Okay. I don't know what that means. Too low of DE over DX means energy is not deposited within a critical radius, so no nucleation happens. So I think what that means is that charged particles don't lose their energy in a big enough burst to jostle the water enough for it to click into ice shape.

So it only picks up uncharged particles, basically. And there's even some uncharged particles like gamma rays that don't set it off. So why is this good? Dark matter is a hypothetical form of matter, right? That is basically has to exist for the world, for like the universe to make sense. Is that pretty much what? Yeah, sure. It's never been observed, but it's also thought to have similar properties to uncharged particles. So the team behind the chamber thinks that this might be a really easy way

to positively identify interactions between dark matter and real matter. So particle detectors search for dark matter by watching for unexplained nudges of atoms in the chamber that they're passing through. They nudge the nuclei of the atoms. But they also, regular ones pick up, like ones up until now, pick up lots of interference from charged particles.

So you have to like screen for all those, which makes it way more complicated. But this one would effectively just automatically screen for that. And because water is hydrogen, which is the lightest molecule is that right oh shit they think they could search for way smaller pieces of dark matter than they've ever been able to search for before because it's lighter and it'll be easier to nudge so how would they know if they found dark matter is that charged particles bounce and scatter in the chamber and you can see video shot like super slow of the charged particles coming in and then like splitting off and making lots of different nucleation points at once but they theorize that

dark matter would only make one nucleation point so they basically like just search their videos for a single nucleation point do you mean uncharged particles yes whatever one one hits the thing. Okay. You just said charged. Uncharged particles scatter when they hit the water. So a bunch of nucleation sites at once. But they think that dark matter would only interact once

with what it was passing through and not scatter. So they have to look for a video of that happening. And then they would hypothetically have an interaction. Like neutrinos are just this field of particles that are passing through everything all the time. Is that the idea for dark matter too? Is there just a field of dark matter that permeates everything? It's not supposed to be a field.

It's supposed to be particles. It just doesn't interact with anything. It doesn't even interact with itself. All it has is mass. But it has mass, and so it affects how the galaxy moves around. So it's very possible that it's like... It only affects through gravitational force. That it's like literally impossible to record it nudging anything?

Yeah. Okay. Yeah, I mean, we don't know. Okay. We really don't know anything about dark matter except that it has gravity. I mean, all we really know is that there is more gravity than there should be.

And dark matter is an explanation for that. So we could, in 10 or 100 years, realize that it's something else and call it something other than dark matter. So we've got Stefan's Plasmon Resonance Diving Boards to measure a gap that light can't even get into. And Sam has a team

studying super cold water to try and detect dark matter because it will super freeze that water if any dark matter flows through it, maybe. Okay. Three, two, one. Sam. Oh. I, two, one.

Sam. Oh. I'm back, baby. You reached out to the scientist. It is. That's big. He was really nice. He wrote me back really fast.

He was like, no one cares about my dark matter snowballs. I care. And I will leave his paper in the show notes and maybe paraphrase his explanation of what he sent to me also to help you figure it out at home. Where's our show notes? The show notes are at scishowtangents.org. If you click on any episode, it'll bring you to a page with our notes and our research and stuff. And now it's time to ask the science couch.

We've got some listener questions for our couch of finely honed scientific minds. This is from at pottery geek who says, so atoms are a lot of space and a little particle. Do the particles even touch each other? Any of them, like even a little. So it depends on how you define touch. Yeah. It depends on how you define particle too. Like what is anything at that point? It's just excitations in a field. So like, yeah, your butt isn't touching this couch even though it feels like it. You're like hovering just slightly over it.

In the macro world, it's touching. Yeah, I mean, we say touch because... It's the only useful way to talk about it. We can sense all the things like the firmness and the... So how do we sense all the things? Electricity? Yeah, electromagnetic interaction. Phew.

If they did touch each other, would that be really bad? So there is a case... I can step through the different definitions of touch because there is a case where they can be touching. Neat. Because that's where physics gets really wibbly wobbly. One definition of touch when you're talking about atomic things is when two things influence each other. And so under that definition, which is the broadest, all atoms are always touching because like its wave function extends out.

So I'm touching you. Wait, so all atoms are always touching every other atom? Yeah, so like I'm touching you right now. I'm touching the listener of this podcast right now. Like by virtue of the listener hearing what we're saying? No. Or no, by virtue of like I have mass, they have mass, and so my mass interacts with their mass.

In the same way that like gravity from very, very distant objects is still affecting us just like almost indistinguishable right but that is also true of electromagnetism and the strong force and the weak force even the ones that have very tiny distances even the weak force stretch even the weak force sam yeah so that definition of touch useless definition two is touch is when two objects influence each other significantly so like a little asterisk on top of that first definition enough that like my nerves fire so sitting on this chair sitting on this chair with an atom you consider like the size of the atom to be

the sphere that contains 95 of the atom's electron mass. So that's what we talk about when we're like orbital spheres and things like that. Like how big an atom is, is where 95% of its mass is. Because if you say 100% of its mass... That's everything. It's everything. What do you mean everything? Everything.

Probability fields. Oh no. Yes. This is so stupid. It's a lot of math. And so with this definition, you're saying that atoms are touching when that region of 95% of them start to overlap. And that can be like a bond, a chemical bond. When two atoms are bonded, then they overlap enough to be considered touching.

Oh, yeah. Even if they're not bonded, they could still influence each other's size. Yeah. Even I think me sitting. Okay. It squishes the atoms some. Doesn't overlap them. are not bonded, they could still influence each other's size. Even I think me sitting, it squishes the atom some. It doesn't overlap them. Overlapping probability fields of where an electron may or may not be.

So, you ready for the next one? Do things touch? Just you wait. The 100% of an atom's size is the universe. Keep going, Sari. And then if you consider touching as two objects residing in the exact same location.

Yeah, okay. So like if you were actually like pressed up against something else, the Pauli exclusion principle, which you learn about in chemistry, says that like electrons can never occupy the same space as one another. In the probability field, there will be distinct electrons. There will never be two electrons in one spot. But because physics, there is a material, I think, known as a Bose-Einstein condensate, where at very low temperatures, some atoms can exist at the same location as other atoms i'm not going to try to explain it beyond that but it's just like near absolute zero they

quote coalesce into a single quantum mechanical entity that's all simple answer to a simple question so everything's all the same and nothing's touching. No, everything is all different and nothing's touching. Or we all occupy the same quantum mechanical entity and everything is touching. That sounds bad. Basically, we should think about touching not in physics ways, but in normal human ways. Okay, good. Do not correct your children when they say, I touched that dog poop. And say, well, technically, your electromagnetic

field approached it. If you want to ask the science coach your questions, and how could you not after this, you can tweet us at SciShowTangents. We will send out the topics for every episode that is upcoming, so you can find out what the topic is

and let us know if you have any relevant questions. Thank you to AwesomeTK at Casual Peruser and everybody else who tweeted us your questions this episode. Final scores! Stefan, you came in with nothing. I freaking did terribly. Yeah, you did. And then

Sari's got one and then I've got two and then Sam took the lead. Still in last place but I made up a lot of distance. Yeah. You and Matthew, that scientist. Real dream team. Thank you, Matthew. Thank you, Matthew.

If you like this show and you want to help us out, very easy to do that. You can leave us a review wherever you listen. That's very helpful. It helps us know what you think about the show. Also, we're going to be looking at iTunes reviews for topic ideas for future episodes, so you can leave those in there. Second, tweet us your favorite moment from the episode, because

I want to know if it's about ferrets or about diapers or about poop. We got very excited this episode, and by we, I mean a lot of me. And finally, if you want to show your love for SciShow Tangents, just tell people about us! Thank you for joining us. I've been Hank Green. I've been Sari Reilly.

I've been Stefan Chin. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and the wonderful team at WNYC Studios. It's greeted by all of us and produced by Caitlin Hoffmeister and Sam Schultz, who also edits a lot of these episodes along with Hiroko Matsushima. Our editorial assistant is Deboki Chakravarti. Our sound design is by Joseph Tuna

Medish. Our social media organizer is Victoria Bongiorno, and we couldn't make any of this without our patrons on Patreon. Thank you! And remember, the mind is not a vessel to be filled, but a fire to be lighted. But, one more thing. Speaking of poop, for a lot of creatures that poop, like us,

the intestinal muscle movements that make pooping possible are triggered by neurotransmitters being released from motor neurons. But for the tiny roundworm C. elegans, its intestinal cells, not its nerve cells, release protons that stimulate muscles and make them poop. Which is very biologically unexpected. That's biologically unexpected. I'll say. That's a proton poop.

That was a great science joke, Stephanie. Yes. It's a proton pump like a thing. Yeah. Okay.