Nikola Tesla Fell In Love with a Pigeon

What do lightning, wireless electricity, Cambridge dining etiquette, hypnosis, and a lovestruck pigeon have in common? The answer is (of course) Nikola Tesla. In this episode of The Rest Is Science: Field Notes, Michael and Hannah experience a real Tesla coil, exploring the spectacular physics behind one of Tesla's most famous inventions. Why do these devices create miniature lightning storms? How did Tesla dream of delivering wireless electricity to the entire planet? But there was a stranger side to Tesla's life too, from his fear of pearls to the heartfelt story of the white pigeon he claimed to love "as a man loves a woman." Plus, your questions: the science of hypnosis, the oldest symbols still in use today, why Cambridge professors have personal napkin rings, and whether ‘nothing’ can ever truly exist. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley + Jack Meek Animator: Sam Benson Video & Social: Bex Tyrrell Assistant Producer: Lucy Lipscombe Producer: Simona Rata Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Michael Stevens?

  Hello and welcome to The Rest Is Science. I'm Michael Stevens.

• 0:02Hannah Fry?

  I'm Hannah Fry, and this is an episode of Field Notes, which is where Michael and I empty our houses of any old scientific linked crap that we've got lying around and bring it to you for your entertainment.

• 0:12Michael Stevens?

  You're welcome.

• 0:13Hannah Fry?

  I'm speaking out of turn here. These are all carefully curated objects that are genuine scientific interest.

• 0:19Michael Stevens?

  Very true.

• 0:19Hannah Fry?

  And today I'm bringing in an object that was given to me as a gift by Ramesh Ranganathan.

• 0:24Michael Stevens?

  Oh, the comedian.

• 0:25Hannah Fry?

  The comedian, the brilliant comedian. He gives a gift to every guest who appears on his podcast. This is what he gave me. I would say it is somewhere between extremely boring and potentially lethal.

• 0:38Michael Stevens?

  I love that.

• 0:39Hannah Fry?

  That's what we've got coming up.

• 0:50Hannah Fry?

  This episode is brought to you by Cancer Research UK.

• 0:53Michael Stevens?

  Here's something strange. Your DNA contains more ancient viral fragments than genes. The genes that build our cells make up only 2% of our DNA. And for years, that is what scientists focused on. They treated the rest, the ancient viruses and stuff, as junk.

• 1:13Hannah Fry?

  But now we know that that hidden majority, sometimes called the dark genome, influences how our biology works and how diseases like cancer behave.

• 1:24Michael Stevens?

  It's a reminder that progress rarely comes as a single breakthrough. It builds gradually. Cancer Research UK plays a central role in that progress, supporting decades of research into over 200 types of cancer, work that's helped double survival in the UK over the past 50 years.

• 1:43Hannah Fry?

  For more information about Cancer Research UK, their research breakthroughs, and how you can support them, visit cancerresearchuk.org/the rest is science.

• 1:54Speaker 02

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• 2:38Speaker 02

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• 3:36Speaker 03

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• 3:59Hannah Fry?

  Do you know what this is?

• 4:00Michael Stevens?

  It's a Tesla coil.

• 4:01Hannah Fry?

  It is a Tesla coil.

• 4:03Michael Stevens?

  I've seen many, many short videos about these where they're being used, but I don't know what it's doing or how it works.

• 4:08Hannah Fry?

  Have you ever played with one?

• 4:10Michael Stevens?

  I've never played with one. I've seen giant ones at science museums and I just watch and I go, oh, I better look that up someday to learn how it works, but I don't know.

• 4:18Hannah Fry?

  Maybe today is the day, Michael.

• 4:20Michael Stevens?

  Today might be the day.

• 4:21Hannah Fry?

  Maybe today is the day. Okay, so what it's doing is it's basically a transformer. So it's a, it's a way to step up the voltage from a, from a current. So normal, normal transformers, I don't know, if you like buy something in America and then use it in the UK or vice versa, you need a transformer because it's 240 volts in the UK and 120?

• 4:44Michael Stevens?

  Yeah.

• 4:45Hannah Fry?

  What is it in the US?

• 4:46Michael Stevens?

  It's less in the US.

• 4:48Hannah Fry?

  Less. Anyway, less. But what this is doing is it has two circuits that are tuned to the same resonant frequency. So what it does is it sort of sloshes the electricity backwards and forwards between them to just really amp up, amp up, amp up the voltage. Yeah.

• 5:06Michael Stevens?

  Right, but it doesn't add more. The, the current is the same. It's the voltage that is increased.

• 5:12Hannah Fry?

  I think the current goes down.

• 5:13Michael Stevens?

  Oh.

• 5:14Hannah Fry?

  Aren't they connected to each other?

• 5:15Michael Stevens?

  I don't know much about electricity, which is even more reason for us to play with this.

• 5:19Hannah Fry?

  Okay, I'll be honest, we're absolutely at the limits of my, my recollection from, from A level physics.

• 5:24Michael Stevens?

  This is an important moment though to show that we're always learning.

• 5:28Hannah Fry?

  Yeah.

• 5:28Michael Stevens?

  Like I'm still at the level of current is like the amount. It's like the flow amount, but then the pressure behind it is the voltage. Like I have a bandograph generator and that produces extremely high voltages, like in the millions. And yet it can spark you and it's, it's not pleasant, but it doesn't kill you because the current is small. It's high voltage, but only a few electrons.

• 5:54Hannah Fry?

  Yeah.

• 5:54Michael Stevens?

  You can have a lot of electrons and barely a difference between two places and you'll get very low voltage, but that current can be really dangerous.

• 6:02Hannah Fry?

  Yeah, absolutely. That's the thing that you have to really worry about. The high, the high voltage is the thing that looks really fancy.

• 6:08Michael Stevens?

  Yeah.

• 6:08Hannah Fry?

  But it's the, the current is the

• 6:10Michael Stevens?

  Makes a big difference.

• 6:11Hannah Fry?

  Dangerous thing. Um, there are two lightning labs actually that I've visited at various points for, for different TV programs. One of which is like this kind, has a massive Tesla coil, unbelievably high voltage, looks incredible. Lightning in the sky, right? It's amazing. And the other one, the high current lightning lab, looks pathetic. Extremely dangerous.

• 6:34Michael Stevens?

  Extremely dangerous.

• 6:35Hannah Fry?

  Extremely dangerous. Okay, the way, the analogy actually that I liked, when I was doing physics at school. Uh, my whole class came up with this like fun idea that actually electricity is just elves. They're like little elves. Who are running around inside the wires.

• 6:48Michael Stevens?

  Is that not true?

• 6:49Hannah Fry?

  I haven't seen it disproven, so.

• 6:51Michael Stevens?

  Exactly.

• 6:51Hannah Fry?

  You know, and look, the whole point of science is it's falsifiable. So, uh, this is something, maybe we should look into it, guys. Maybe we should.

• 6:57Michael Stevens?

  We should.

• 6:58Hannah Fry?

  Um, but the idea is that the current is the number of elves that you have, and the voltage is how much water they're bringing with them in their buckets.

• 7:04Michael Stevens?

  Okay, cool. Yeah, that works for me too.

• 7:06Hannah Fry?

  Okay.

• 7:06Michael Stevens?

  For the purposes of this episode.

• 7:08Hannah Fry?

  For the purposes of this episode, we'll do that. Okay, so what this is doing is caring about the voltage and reducing the current as a result.

• 7:14Michael Stevens?

  Okay, so for those of you listening, this, this box Hannah has brought, it's a plexiglass box. It's clear. You can see all the electronics inside. Which there isn't much. There's mainly empty space in there. There's a couple of transformers. And the box is maybe, I don't know, two inches tall and then it's, uh, uh, depth and length is like maybe four or five inches. But on top, there's a golden disc and a needle is sticking straight up, like a steel needle that gets, gets quite sharp at the tip. And that's about, I don't know, three inches tall. Um, then there's two knobs. One says frequency and one says power and it's plugged in.

• 7:50Hannah Fry?

  All right, should I turn it on? See what, see what happens?

• 7:52Michael Stevens?

  Oh, I guess go ahead. Yeah.

• 7:53Hannah Fry?

  Okay, let's go. Why just, why just move my laptop side the other way?

• 7:56Michael Stevens?

  Okay, that's probably a good idea.

• 7:59Hannah Fry?

  Is it gonna work?

• 8:03Hannah Fry?

  No.

• 8:05Michael Stevens?

  Whoa, okay, yes.

• 8:09Hannah Fry?

  Isn't that cool?

• 8:10Michael Stevens?

  That's really cool.

• 8:12Hannah Fry?

  It made

• 8:12Michael Stevens?

  It was frightened me. Yeah. Okay.

• 8:18Hannah Fry?

  So we should describe what we've just witnessed.

• 8:21Michael Stevens?

  Yeah.

• 8:21Hannah Fry?

  From the very tip of that needle, the sharpest point, there was an explosion of what looked like miniature lightning.

• 8:29Michael Stevens?

  Yeah, lightning bolts in all directions, like a ball. Uh, you know, those, um.

• 8:34Hannah Fry?

  The plasma things.

• 8:35Michael Stevens?

  Yeah, like a plasma ball. When you touch the plasma ball and there's like this lightning bolt that comes from the middle out to the edges. We saw those, it was almost like jellyfish like, that describes the color well, it's like a fluorescent blue.

• 8:47Hannah Fry?

  Yeah. Oh, I would say even pinky almost.

• 8:49Michael Stevens?

  Oh, there's some pink in there too, for sure. Yeah. So there's a, the voltage, what in that spike is getting so strong that the electrons are like, I gotta leave.

• 8:59Hannah Fry?

  Yes.

• 8:59Michael Stevens?

  But they have nowhere to go except into air, which they don't like to go through unless they really have to. That's why it's so explosive.

• 9:05Hannah Fry?

  Yeah.

• 9:05Michael Stevens?

  And I'm hearing pops.

• 9:06Hannah Fry?

  Right.

• 9:07Michael Stevens?

  That popping noise is what, the air?

• 9:09Hannah Fry?

  So what is happening is we are literally ionizing the air.

• 9:13Michael Stevens?

  Yeah.

• 9:13Hannah Fry?

  All of those little arcs that you see coming out. It's, and the purple even, you are turning the air into plasma. Literally as it happens. I mean, that is pretty.

• 9:23Michael Stevens?

  So you're stripping the electrons off the nuclei.

• 9:25Hannah Fry?

  Ripping the electrons off the nuclei in the air.

• 9:28Michael Stevens?

  So what if you lick it?

• 9:30Hannah Fry?

  Uh, I mean, you're welcome to.

• 9:32Michael Stevens?

  Am I? Are you, do you really want that on your conscience? Cause I'll do it. No, I won't do it.

• 9:38Hannah Fry?

  I think it's, I think it's, I think it's probably better not to. But yeah, you can, uh, because I think technically you can touch it, but maybe don't.

• 9:46Michael Stevens?

  I'm not going to.

• 9:47Hannah Fry?

  No. I mean, that was both frightening and.

• 9:51Michael Stevens?

  I didn't think it'd be so loud.

• 9:52Hannah Fry?

  I know. Yeah. The way that this is working though, is, is, it's using resonance. So if you imagine a person on a swing.

• 9:59Michael Stevens?

  Mm hmm.

• 9:59Hannah Fry?

  Right? If you're pushing a child on a swing, if you manage to get them at the right frequency, they can go higher and higher and higher. So what this is, is effectively like two people pushing, right?

• 10:09Michael Stevens?

  Right, right.

• 10:09Hannah Fry?

  Back and forth and back and forth in order to really elevate the, the voltage. I mean, you're getting like hundreds of thousands, if not millions of volts, right at that very tip. Enough to strip the electrons from the air.

• 10:21Michael Stevens?

  Yeah, cause electricity doesn't like to move through air. It's gotta have really high voltage to arc like that.

• 10:26Hannah Fry?

  So in this, uh, in this lightning lab that I went to in Germany, where they had a giant one of these. They put me in a Faraday cage.

• 10:35Michael Stevens?

  Ah, to protect you.

• 10:36Hannah Fry?

  To protect me and then electrocuted me.

• 10:38Michael Stevens?

  But you were okay.

• 10:39Hannah Fry?

  I was okay.

• 10:40Michael Stevens?

  So they shot. Bright blue arcs of electricity at you, but the Faraday cage.

• 10:46Hannah Fry?

  Protected.

• 10:46Michael Stevens?

  Protected you.

• 10:47Hannah Fry?

  Yeah. How much do you know about Tesla, by the way? Cause he is a, he's a wild guy.

• 10:51Michael Stevens?

  Not as much as I should, so, so tell me.

• 10:53Hannah Fry?

  Okay. So he has, um, he had these, these really quite bonkers ideas. One of the things that he really wanted to do was he wanted to sort of use this, the, these general ideas to broadcast electricity through the earth, right?

• 11:06Michael Stevens?

  Oh, right. So rather than having to use a wire.

• 11:09Hannah Fry?

  Yeah, you could just, you could just, everything would just work. So, um, and he managed to get funding for this as well. So he, in 1901, he, uh, he was backed by JP Morgan. And he started to build something called the Wardencliff Tower on Long Island. Uh, and the, uh, the pitch was that it was going to be wireless, uh, telegraphy. Uh, but what he actually wanted to do was to build a sort of planet sized Tesla coil, right? And they would use the earth as this, this giant kind of resonant cavity.

• 11:36Michael Stevens?

  Yeah.

• 11:37Hannah Fry?

  And then anyone would be able to just stick an antenna in the ground and then pull electricity kind of for free.

• 11:43Michael Stevens?

  Out of the ground.

• 11:43Hannah Fry?

  Yeah. And then Morgan found out about this, JP Morgan found out about this and he was like, actually I'm making quite a lot of money from metered utilities at the moment. So I'm going to go with no. So he shut off the funding that.

• 11:53Michael Stevens?

  But wouldn't it have worked?

• 11:54Hannah Fry?

  So, no, probably not. There's like all kinds of slight problems about, um, how far this thing, it kind of, the level of power that you would need to put into it would have been so absurd.

• 12:06Michael Stevens?

  Yeah.

• 12:07Hannah Fry?

  Even if you did manage to get it to work, which you probably wouldn't have done, it would have had all of these repercussions. So like, you know, fences, for example, would start humming.

• 12:13Michael Stevens?

  Yeah. I was going to say anything stuck in the ground.

• 12:15Hannah Fry?

  Bathtubs, you know, you get a massive electric shock from your bathtub. Probably your fillings and your teeth, they would like start to rattle.

• 12:21Michael Stevens?

  This doesn't sound good.

• 12:22Hannah Fry?

  Birds also would have a terrible time. Birds would navigate using electromagnetic.

• 12:27Michael Stevens?

  Right.

• 12:28Hannah Fry?

  Fields essentially. Bees also game over. Um, yeah, it would, it would have been pretty bad. It also probably, probably would have been strong enough to actually cook flesh in the immediate vicinity of the, of the transmitter.

• 12:41Michael Stevens?

  Yeah, it's on Long Island.

• 12:41Hannah Fry?

  You know, that is long.

• 12:44Hannah Fry?

  It could be worse places. Uh, Tesla though, he was really into resonance. Love this stuff. He, um, claimed to have shaken a building off of its foundations using just a, a, a resonant device that was this kind of size.

• 12:56Michael Stevens?

  Yeah, yeah.

• 12:57Hannah Fry?

  And, I mean. Maybe not completely absurd. We do know the buildings can get taken down by resonance, right? There's the the famous bridge. What's it called? The Tohome?

• 13:08Michael Stevens?

  Yeah, the Tacoma.

• 13:09Hannah Fry?

  Tacoma Bridge, right.

• 13:10Michael Stevens?

  Bridge.

• 13:11Hannah Fry?

  Yeah. Then there's the Millennium Bridge as well, which had problems with resonant frequencies, uh, which ended up being very wobbly. Didn't get.

• 13:19Michael Stevens?

  And that one's here.

• 13:20Hannah Fry?

  That one's here, exactly. Um, and so there's, there is something in it that if you find the resonant frequency of a particular structure, it can sort of shake itself apart. His story was that he had this oscillator, it was kind of shaking, shaking this building, tuned it to the resonant frequency of the steel structure. And then nearby buildings started shaking too. And then plasters started falling and then windows started cracking and then police were called. And he was like, no, this is awful. And got a sledgehammer and smashed it to pieces. And then he later told a reporter that he could split the earth like an apple if he wanted to using resonance.

• 13:53Michael Stevens?

  Nice.

• 13:54Hannah Fry?

  I mean, look, he was a salesman.

• 13:55Michael Stevens?

  He was.

• 13:56Hannah Fry?

  That's what, that's definitely what we can say. He also, when you are in a room with one of these, if you have one of these, um, you can light up fluorescent bulbs without physically touching them.

• 14:08Michael Stevens?

  Yeah.

• 14:09Hannah Fry?

  Um, because there is just enough charge that is in the air.

• 14:14Michael Stevens?

  In the air for a fluorescent bulb to light up, yeah.

• 14:17Hannah Fry?

  Exactly. So, you know, this idea of like wireless charging, it kind of does sort of work. Um, if you, if you don't mind your teeth rattling around in your head.

• 14:27Michael Stevens?

  I do, though.

• 14:28Hannah Fry?

  I sort of do as well. The other things about, other things about Tesla, he's a kind of a, sort of a really strange guy. So he could, he could recite entire books from memory.

• 14:38Michael Stevens?

  Okay.

• 14:39Hannah Fry?

  Um, what a skill.

• 14:41Michael Stevens?

  He's ready for Fahrenheit four fifty one.

• 14:43Hannah Fry?

  He's, he's ready for it.

• 14:44Michael Stevens?

  Burn all the books. We'll just have Tesla memorize them.

• 14:46Hannah Fry?

  Just, just exactly. Why not? And, uh, but he was also really terrified of pearls. Um. He would refuse to speak to any woman who was wearing pearls.

• 14:55Michael Stevens?

  I didn't know that.

• 14:56Hannah Fry?

  Yeah.

• 14:56Michael Stevens?

  You've got a pearl right there on your laptop.

• 14:58Hannah Fry?

  I do. Sorry, Tesla.

• 15:00Michael Stevens?

  Sorry, Tesla, but you know, yin and yang, they have to be together.

• 15:04Hannah Fry?

  Exactly. In fact, I should I put that there deliberately just to sicken him.

• 15:06Michael Stevens?

  I can tell.

• 15:07Hannah Fry?

  Just to sicken him. Um. He also fell in love with the pigeon, but like for real, a white pigeon uh that he had in New York. And um when the pigeon died in his arms in a hotel room, he wrote, I love that pigeon as a man loves a woman and she loved me. As long as I had her, there was a purpose to my life.

• 15:25Michael Stevens?

  That's very sweet.

• 15:26Hannah Fry?

  It's very sweet, isn't it?

• 15:27Michael Stevens?

  I need to learn a lot about electricity.

• 15:30Hannah Fry?

  The thing is, I've got to be honest with you. They are sort of a novelty item.

• 15:33Michael Stevens?

  Yeah, I mean, I don't know what else you're gonna do with it. You can you can stick flowers and stuff on the needle and watch them. They get damaged, possibly burned after a while from from those arcs.

• 15:44Hannah Fry?

  I think what's what's worth saying is that this is a point in time when electricity is so exciting. You know, first you had Volta, who who was the first person really to to create a steady electric current. Then you have Faraday, who comes along and manages to to reliably create it and and harness it in some ways. All of this stuff is going on, but this was really the point where it's like, actually, we can do stuff with this.

• 16:11Michael Stevens?

  Right.

• 16:12Hannah Fry?

  You know, Edison is around. He's like looking at light bulbs and things. There's like, there's there's telephone wires that are being strung up around the place. It's like this real age of excitement and thrill. And lots of people were were just totally enamored with with just the very power of electricity.

• 16:31Michael Stevens?

  That's a good point. I think we always have something like that in society. Today, maybe it's AI. Before and until this day, it was nuclear weapons. Things where someone could threaten to rip the world in half with it. And it was changing society dramatically. And with electricity? That's a huge jump to go from, I can't speak to my cousin who's halfway across the country unless I want to wait. Suddenly with wires, with telegraphy.

• 17:01Michael Stevens?

  The world became so small so quickly. It was a Copernican shift.

• 17:05Hannah Fry?

  Yeah.

• 17:06Michael Stevens?

  And there was a time when this was part of that.

• 17:10Hannah Fry?

  I mean, this, this was sort of witchcraft to the, to the generations that existed before.

• 17:15Michael Stevens?

  That's right. It was unnatural.

• 17:16Hannah Fry?

  Yeah.

• 17:17Michael Stevens?

  And today we take it for granted.

• 17:18Hannah Fry?

  Yeah, godlike powers, lightning in your room.

• 17:21Michael Stevens?

  Light at night.

• 17:22Hannah Fry?

  Hmm.

• 17:23Michael Stevens?

  Cold, cool light. Well, they were warm lights, but they didn't, they didn't, you don't, didn't run out of oil.

• 17:28Hannah Fry?

  No, absolutely. I have actually heard people compare the invention of AI or the, I guess, the advances in AI to the discovery of electricity.

• 17:38Michael Stevens?

  Yeah, certainly.

• 17:39Hannah Fry?

  Yeah, I think it probably is, you know, the first time I heard it, I was like, come on. But actually, as time's gone on, I think, I think it probably is actually as seismic as that. In the way that now it's really difficult to imagine basically anything without our use of electricity and how we've managed to harness it.

• 17:55Michael Stevens?

  Oh, yeah, yeah.

• 17:57Hannah Fry?

  Well, I hope you enjoyed that.

• 17:58Michael Stevens?

  I really did.

• 17:59Hannah Fry?

  Yeah, it's cool, isn't it? We're going to be back after the break with some of your questions.

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• 19:49Hannah Fry?

  Okay, Michael, first question is for you.

• 19:50Michael Stevens?

  All right.

• 19:51Hannah Fry?

  What is the oldest symbol that represented something when it was created and is still used today to represent the same thing? This is by Ethan, by the way, this question.

• 19:59Michael Stevens?

  I love this question. I've looked at things similar, like what's the oldest song that we all basically still know today?

• 20:09Hannah Fry?

  Oh, yeah.

• 20:10Michael Stevens?

  And the answer there, I think, a good one, you know, we can't always be totally sure, but it's probably "Greensleeves."

• 20:16Hannah Fry?

  Really?

• 20:17Michael Stevens?

  It's a very old song, and people might not know the name of it, but they'll recognize it when they hear it.

• 20:22Hannah Fry?

  Is it this one? Dun, dun, dun, dun, dun, dun, dun. No, that's what's... Wait, how does it go?

• 20:29Michael Stevens?

  Look at my greensleeves, aren't they cool? No, I...

• 20:32Hannah Fry?

  Wait.

• 20:33Michael Stevens?

  If you play it, I'll know it. I think you're... You think you were right.

• 20:36Hannah Fry?

  No, I don't think I was.

• 20:37Michael Stevens?

  Da, da, da, da, da, da.

• 20:38Hannah Fry?

  That's it, that's it, that's it, that's it. I remember hearing that was written by Henry VIII.

• 20:42Michael Stevens?

  It may have been, I don't even know.

• 20:43Hannah Fry?

  Seems unlikely.

• 20:44Michael Stevens?

  But this, the question is...

• 20:45Hannah Fry?

  Much more likely he took credit for it.

• 20:48Michael Stevens?

  What's the oldest symbol that we still recognize today? And this, it, first of all, it really comes down to what you think a symbol is. So the definition I'm going to use is that a symbol is something that represents something else through an arbitrary or conventional connection.

• 21:08Hannah Fry?

  Okay.

• 21:09Michael Stevens?

  So, for example, a handprint, I'm not considering a symbol.

• 21:14Hannah Fry?

  Agreed.

• 21:15Michael Stevens?

  Because that's an index.

• 21:16Hannah Fry?

  Yeah.

• 21:17Michael Stevens?

  It's an, it's, it iconically looks like a hand, and it's a sign that a hand had been there. A footprint, these things are not, for me, symbols.

• 21:23Hannah Fry?

  Agreed.

• 21:24Michael Stevens?

  Alphabetical letters are symbols.

• 21:26Hannah Fry?

  Mm-hmm.

• 21:27Michael Stevens?

  A, the letter A, and then what it means, what it's referring to, are really different.

• 21:31Hannah Fry?

  Right.

• 21:32Michael Stevens?

  And it's through convention, it's through our social rules that we learn, A means "ah." A those sounds. Anyway, I think that like gestures came before graphical representation. Animals have body postures and things and gestures, but those are also not really symbolic. They kind of biologically happen. Even even this meaning yes and this meaning no. There are hypotheses that that those actually come from infant behavior. That like to to go like this is to to reject a nipple.

• 22:04Hannah Fry?

  Ha ha.

• 22:05Michael Stevens?

  And that this is to like suck on a nipple.

• 22:08Hannah Fry?

  Give me the boob. Give me the boob.

• 22:09Michael Stevens?

  I again, this is just a guess. We can't really be sure, but.

• 22:13Hannah Fry?

  But it's not uniform, right? Because in India, this means yes.

• 22:17Michael Stevens?

  That's true. Uh, but they still have no. I mean, this doesn't mean yes. This means like I'm following.

• 22:24Hannah Fry?

  I think it sort of does, though, you know?

• 22:26Michael Stevens?

  I think this is like more of the yes of like, yes, I hear you.

• 22:29Hannah Fry?

  Ah.

• 22:29Michael Stevens?

  Rather than the yes, I consent, kind of.

• 22:31Hannah Fry?

  It can be all three apparently. Let us know in the comments, by the way, because we're clearly at the limit of our of our.

• 22:36Michael Stevens?

  Yeah, yeah, we are. But I can, I can see the the origins of things like no.

• 22:45Hannah Fry?

  Yes, I agree.

• 22:45Michael Stevens?

  And stop. And that is like you're actually stopping something's motion.

• 22:49Hannah Fry?

  Agreed.

• 22:49Michael Stevens?

  If it's too tied to physical things, then I don't find it very symbolic.

• 22:54Hannah Fry?

  Sure.

• 22:55Michael Stevens?

  So I think my answer to the question is going to be the connection between a mark, like a notch.

• 23:02Hannah Fry?

  Mm hmm.

• 23:02Michael Stevens?

  And the concept of number.

• 23:05Hannah Fry?

  Mm hmm.

• 23:05Michael Stevens?

  One notch means one sheep. Like, that is symbolic, because that one notch doesn't have to mean oneness. And yet, as soon as it did, notches could have meant days, or how many sheep you you moved here. And you want to make sure that you get a notch for every sheep that comes back. But even before those notches, there were like tally counters, uh, like, like a, like a little stone.

• 23:31Hannah Fry?

  Hmm.

• 23:31Michael Stevens?

  Every time you you had a sheep walk by, you could put a stone in a bag. And then when you brought the sheep back in, you would take a stone out for each sheep, and you would know that they'd all come back, because you were associating the pebble with one sheep. Like, that is, that that coin being a symbol for the sheep is a big leap.

• 23:48Hannah Fry?

  Right.

• 23:49Michael Stevens?

  That, to me. Basically, number, any kind of symbol, a notch, a dot, a pebble, a stroke, I don't know which came first, but those representing amount or representing an individual or any individual would probably be the first step in symbolic thinking.

• 24:08Hannah Fry?

  Yeah, I think that's probably right. Actually, I was thinking about, I was thinking, when the question came through, I was thinking about sort of physical marks on paper.

• 24:19Michael Stevens?

  I know, and they may want an answer more like that. I am talking about physical marks, like, like a dash for a one, or, or just a slash for a one.

• 24:29Hannah Fry?

  Because if it is, if it is which, which letter slash symbol is the oldest, I mean, zero's got a good shout, isn't it?

• 24:37Michael Stevens?

  Well, what, why did the Romans neglect it so much?

• 24:40Hannah Fry?

  I mean, sure, but the Indians were way ahead.

• 24:41Michael Stevens?

  Yeah. So, circles and squares and spirals, we find in the most ancient cave paintings. And we find a lot more of those kind of like doodles than we do the more famous and well-known depictions of bison and, and other animals. So, what I was hung up on with geometric shapes is that although as a shape, it's been around forever, as a thing that we doodle, but as a symbol for something specific, it's changed. And we don't really know what they were trying to represent with the spirals they drew, right? So.

• 25:22Hannah Fry?

  What about in language? Is there a language, what's like the oldest language or oldest letters that have continually been in use? Do we know? Because you could reasonably pick up some ancient Greek texts.

• 25:35Michael Stevens?

  Yeah.

• 25:36Hannah Fry?

  And sure, the words might be different, ancient Greek to modern Greek, you know, sort of, there's a really big distinction in the languages. But the letters have some commonality, right?

• 25:47Michael Stevens?

  Yeah, but I, I think we need to go further back than Greek letters. I'm thinking that. You can go back, you know, a hundred thousand years to just literally like, these notches represent

• 26:00Hannah Fry?

  One.

• 26:01Michael Stevens?

  One thing that I gave you and this helps me remember. I'm externalizing thought.

• 26:06Hannah Fry?

  Yeah.

• 26:06Michael Stevens?

  In a symbolic way.

• 26:08Hannah Fry?

  Yeah.

• 26:08Michael Stevens?

  Though it is still a cool question, like which doodle, which like graphical symbol has always meant what it means even to this day? The problem is there are a lot of old ones, like the swastika is super old. And if you look this question up, the spiral or a swastika is like super, super ancient. But what it has symbolized has certainly changed a lot and meant different things to different people at different times. So I kind of didn't include that one. I was really like, I want this to be so the same still.

• 26:44Hannah Fry?

  Yeah, I like that a lot.

• 26:45Michael Stevens?

  So I'm going, I'm going with the, a notch.

• 26:47Hannah Fry?

  Absolute lol if your answer had been the swastika.

• 26:51Michael Stevens?

  I know. When I saw that one.

• 26:53Hannah Fry?

  Absolute curveball.

• 26:54Michael Stevens?

  I was like, oh, I hope that's not the answer.

• 26:58Hannah Fry?

  Yeah. Well, thankfully it isn't because we've got little pebbles.

• 27:00Michael Stevens?

  Oh, can I just say that?

• 27:01Hannah Fry?

  Oh yeah, go ahead.

• 27:02Michael Stevens?

  Like, there's a good argument to be made that, that an arrow is quite old because the arrow, meaning direction, would have come from the use of spears even before

• 27:16Hannah Fry?

  Right.

• 27:17Michael Stevens?

  graphical language. So, and arrows have always meant a direction.

• 27:24Hannah Fry?

  Yeah.

• 27:24Michael Stevens?

  But here they draw attention and that's very much what, uh, what symbols do. They draw your attention to something else. And the arrow is trying to do that, even if it's drawing your attention to something else on the surface. So if you're looking for an actual shape you can draw, I think arrow.

• 27:39Hannah Fry?

  I think, I think you're probably right.

• 27:40Michael Stevens?

  It's pretty good.

• 27:41Hannah Fry?

  Yeah. Arrow's got to be older than written language.

• 27:45Michael Stevens?

  Yeah.

• 27:46Hannah Fry?

  Yeah, definitely. I like that a lot.

• 27:49Michael Stevens?

  I don't know if any of this is correct, but it's hard to know because we're talking about prehistoric things.

• 27:53Hannah Fry?

  Absolutely. Okay, here's another question from Sam, who asks, in a recent episode, you briefly mentioned hypnosis, but I was wondering what causes hypnosis? Have you ever been hypnotized?

• 28:03Michael Stevens?

  No, I haven't. I don't think I'm, I resist too much.

• 28:08Hannah Fry?

  I resist too much as well. I did actually do an episode with the BBC where me and my co-host, Adam Rutherford, were hypnotized and it didn't work on me, but it absolutely did work on him.

• 28:20Michael Stevens?

  Yeah, and I believe it. I believe that it's a real thing.

• 28:23Hannah Fry?

  I mean, the evidence is really, really strong that it properly works.

• 28:26Michael Stevens?

  Yeah, it really does change your connection to like your own will.

• 28:30Hannah Fry?

  Yeah.

• 28:31Michael Stevens?

  And you do things, but you just don't know that you're doing them. It feels like you're being controlled.

• 28:36Hannah Fry?

  But actually, you're sort of complicit. You're sort of playing along nonetheless. So the sort of best understanding of it is that it's like a focused state of attention, essentially. It's like you kind of reduce your peripheral awareness, you kind of heighten responsiveness to suggestion.

• 28:53Michael Stevens?

  Yeah.

• 28:53Hannah Fry?

  It's like the opposite of multitasking, essentially.

• 28:55Michael Stevens?

  Oh, interesting. Yeah, that's a good way to look at it.

• 28:58Hannah Fry?

  But you see this, you know, you can hypnotize people and put them in brain scans and you can see that they have, you know, reduced activity in certain parts of their brain and then increased activity in other parts of their brain. There's this sort of more communication between the brain's planner, as it were, the prefrontal cortex, and the part that tracks what's going on inside of your body, which, you know, this might be one of the reasons why it's so effective for pain control, which it is.

• 29:23Michael Stevens?

  Whatever it's doing is really fundamental to the concept, the experience of consciousness. Because, you know, they found that you cannot hypnotize people to do things they wouldn't normally do. There's a wonderful study where they, they took like actual acid and they demonstrated to people who were not hypnotized that this will hurt someone if this splashes on them. Then they hypnotized the people, did a magic switcheroo and gave them just water. And then they said, when I say snap my fingers, you will throw this acid all over this researcher. And they wouldn't do it. Now, if they had done it, no one would have been hurt.

• 30:01Hannah Fry?

  Because it was water.

• 30:02Michael Stevens?

  Yeah, but significantly, even though the hypnotized person felt that they had no sense of will over their actions, some deeper part of them still did and was like, no.

• 30:13Hannah Fry?

  I don't want to do that. I remember you saying, I think probably off camera, off microphone once, that you thought that consciousness was essentially our own body's ability to have a veto on our

• 30:25Michael Stevens?

  Yeah.

• 30:25Hannah Fry?

  behavior.

• 30:26Michael Stevens?

  Yeah.

• 30:26Hannah Fry?

  I really like that idea.

• 30:27Michael Stevens?

  And you lose that veto power when you're hypnotized.

• 30:30Hannah Fry?

  Right, right.

• 30:32Michael Stevens?

  You cannot say no to your unconscious. Your unconscious, or I think non-conscious is a better word to use, but it still can say no to stuff. It still will refuse to harm others, for example.

• 30:43Hannah Fry?

  Yeah.

• 30:44Michael Stevens?

  But you don't feel like you vetoed that instruction.

• 30:49Hannah Fry?

  By the way, about 15% of people are highly hypnotizable.

• 30:52Michael Stevens?

  Okay.

• 30:52Hannah Fry?

  And about the same on the other end, about 15% of people are unhypnotizable. And then everyone else in the middle is like moderately responsible.

• 31:00Michael Stevens?

  Okay.

• 31:00Hannah Fry?

  Responsible, responsive.

• 31:01Michael Stevens?

  Responsive, suggestible?

• 31:03Hannah Fry?

  Suggestible. I mean, they do say that it sort of works better on people who have better imaginations, that it's kind of a compliment to be able to get yourself in this state.

• 31:11Michael Stevens?

  Sure.

• 31:11Hannah Fry?

  I did try it for childbirth, actually.

• 31:15Michael Stevens?

  Okay. What, to lessen the pain?

• 31:18Hannah Fry?

  Yeah, so hypnobirthing, it's called.

• 31:20Michael Stevens?

  It's called what?

• 31:21Hannah Fry?

  Hypnobirthing.

• 31:22Michael Stevens?

  Hypnobirthing.

• 31:23Hannah Fry?

  Yeah, so you do it essentially to yourself. You practice it.

• 31:26Michael Stevens?

  Yeah.

• 31:26Hannah Fry?

  For ages and ages before. And I definitely think that it would help to calm yourself, right? It would sort of like help you to get yourself into a much better mental state of mind. Because the thing is, when it comes to pain especially, pain is not this objective fact. Much of pain is actually constructed within your own mind.

• 31:45Michael Stevens?

  Right.

• 31:45Hannah Fry?

  Right? There are really extensive experiments on this where you where you subject an individual to a a sort of quantified amount of pain, right? Like a particular needle pressing at a particular point and a particular strength over and over again, and then change the environment that they find themselves in, change the mental state that they're in.

• 32:01Michael Stevens?

  And their experience of it changes.

• 32:03Hannah Fry?

  Completely changes, yeah.

• 32:04Michael Stevens?

  Yeah.

• 32:04Hannah Fry?

  So I mean, I think that there is free analgesia, as it were. Tap into by by, you know, harnessing the power of the mind.

• 32:11Michael Stevens?

  So did it work?

• 32:12Hannah Fry?

  Yeah, kind of. It definitely, yes, I would do it again.

• 32:17Michael Stevens?

  Okay.

• 32:17Hannah Fry?

  I I definitely wouldn't say, oh, yeah, it's a completely pain free experience. No, it's like an earthquake in my soul.

• 32:23Michael Stevens?

  Yeah.

• 32:25Hannah Fry?

  But but all the same, all the same, I would definitely do it again. Yeah. Especially when you're doing something that has no side effects, right? There is almost no medical interventions that have zero side effects.

• 32:37Michael Stevens?

  Well, yeah, I've never met someone who was like, oh, I hypnotized myself too much and now I can't walk, right? Like, but but the altered states like that, I would need to learn so much more about because they are so important.

• 32:50Hannah Fry?

  Yeah.

• 32:50Michael Stevens?

  Um, automatic writing is another one. And the thing is, I can't get myself to do a lot of this. Even under ayahuasca, I couldn't let go. Um, but the Ouija board too. Is one of these like people kind of get into a state where they disconnect their actions from their sense of will.

• 33:07Hannah Fry?

  Absolutely love that you just dropped in, dropped in that you were on ayahuasca once during that conversation. Okay, last question. This is from Kayden. Is nothing a thing?

• 33:17Michael Stevens?

  Ah, is nothing a thing? I'd love to hear what you think about this too. I mean, I think that the word causes a lot of confusion because you've got like two types of nothing. You've got nothing, the pronoun, which refers to no thing. For example, in the sentence, nothing is better than God. Okay, I'm saying there is not a thing that is better than God. But then there's the reified nothing, where you treat it like it's its own noun. In the sentence like, well, look, a ham sandwich is better than nothing.

• 33:55Michael Stevens?

  Now, we know those two uses of nothing are different because if nothing.

• 34:01Michael Stevens?

  Is better than God. So nothing is better than God. And a ham sandwich is better than nothing than a ham sandwich is better than God.

• 34:08Hannah Fry?

  Right.

• 34:08Michael Stevens?

  That's not what I'm saying. I'm saying that there is no thing better than God. And a ham sandwich is better than the set, a set that's empty.

• 34:17Hannah Fry?

  Yeah.

• 34:18Michael Stevens?

  Which is, which is a reified, a made into a thing, thing.

• 34:21Hannah Fry?

  It's the difference of defining something as the absence of something and.

• 34:26Michael Stevens?

  And the absence itself.

• 34:27Hannah Fry?

  Right.

• 34:28Michael Stevens?

  But that conceptual leap from no things to what if we called no things? Nothing.

• 34:37Hannah Fry?

  Mm hmm.

• 34:38Michael Stevens?

  Then you can start building and having nothing, but also the container I've put it in. And then I can have a different container of nothing. And suddenly you're constructing numbers from nothing.

• 34:49Hannah Fry?

  Mm hmm.

• 34:50Michael Stevens?

  I think that's the Van Neumann.

• 34:52Hannah Fry?

  Yep.

• 34:53Michael Stevens?

  Set theoretical way of constructing all of the Cardinals.

• 34:56Hannah Fry?

  All of the numbers above. Yeah. Um, hey, look, we did three parts on infinity. You think you're getting away with the us talking about zeros. That's one part of a question and one part of a field. No, it's absolutely not.

• 35:07Michael Stevens?

  No.

• 35:08Hannah Fry?

  Uh, we're coming back to that. I'm, I think though, in the short answer is I think that, uh, no thing is obviously a thing because it's defined in a relation to the absence of, of a thing. But, but nothing as in sort of the absence of anything, the absence itself.

• 35:25Michael Stevens?

  Mm hmm.

• 35:26Hannah Fry?

  I think it is only hypothetical. I think you can't ever actually have it.

• 35:30Michael Stevens?

  I agree. I agree. I agree. Yeah.

• 35:32Hannah Fry?

  In the same way as I think circles are only hypothetical.

• 35:35Michael Stevens?

  Yeah, we can imagine a circle. We can imagine nothing, but there will never be a circle.

• 35:40Hannah Fry?

  There's no perfect circle.

• 35:42Michael Stevens?

  No perfect circle and there's no complete nothing.

• 35:45Hannah Fry?

  Hmm. Yeah. Maybe no infinity either. Maybe nothing, maybe nothing is real. Maybe no thing is real. Maybe, I'm not sure.

• 35:53Michael Stevens?

  Maybe there's, maybe, maybe there's no zero and there's no infinity. And there's also no set.

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• 37:00Michael Stevens?

  That should be its own belief system. I'd like that one.

• 37:03Hannah Fry?

  It certainly should. Well, okay, thank you so much for joining us on this episode of The Rest Is Science. As ever, you can send us your questions, [email protected].

• 37:13Michael Stevens?

  And we'll see you next time.

• 37:14Hannah Fry?

  Certainly will.