The Right Way To Open A Shaken Soda Can

A can of fizzy drink has been violently shaken. The pressure is building, the bubbles are ready to erupt, and Michael Stevens is about to open it. But Hannah Fry has a trick up her sleeve. Can a few taps really prevent an explosion? This week on The Rest Is Science, Hannah and Michael begin with the surprisingly complicated physics of carbonation before tackling a much bigger question: can we really trust science? From the replication crisis and scientific studies that fail to stand up to scrutiny, to the strange incentives that shape what gets published, they explore why even respected scientific discoveries can turn out to be wrong...and why that might not be such a bad thing. Along the way, they investigate whether Archimedes really could have moved the Earth with a long enough lever, why aircraft are designed to withstand enormous pressure changes, and what happens when we lose our curiosity. Plus, an unexpected discussion about nuns, the dangers of absolute certainty, and why asking questions might be one of the most important things we can do.-------------------"For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit https://cancerresearchuk.org/restisscienceCancer 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 MeekAnimator: Sam BensonVideo & Social: Bex TyrrellAssistant Producer: Lucy LipscombeProducer: Simona RataSenior Producer: Lauren Armstrong-CarterChief Digital Officer: Samuel OakleyExec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

• 0:01Speaker 00

  Welcome to The Rest Is Science. I am Michael Stevens.

• 0:03Speaker 01

  I'm Hannah Fry.

• 0:04Speaker 00

  And today, I've got a can of a carbonated beverage.

• 0:09Speaker 01

  We can talk about how many calories there are in there?

• 0:11Speaker 00

  Nope.

• 0:11Speaker 01

  Hey, don't shake it!

• 0:12Speaker 00

  Don't shake it up, right?

• 0:15Speaker 00

  Oh yeah, I can feel how tight it's getting.

• 0:17Speaker 01

  Can you?

• 0:18Speaker 00

  Alright, now do you want to open it?

• 0:19Speaker 01

  No!

• 0:21Speaker 00

  Good, because I don't want you to open it, not yet. Instead, I'm gonna try a little life hack to fix this and make it safe to open.

• 0:28Speaker 01

  Okay.

• 0:28Speaker 00

  Now, have you heard of this before? Tapping the sides?

• 0:31Speaker 01

  Yeah, or tapping the top is the one that...

• 0:33Speaker 00

  Tapping the top is terrible.

• 0:35Speaker 01

  Is it?

• 0:35Speaker 00

  That does not work. Tapping the sides is where it's at.

• 0:38Speaker 01

  Right.

• 0:39Speaker 00

  Should I tell you why now? Or should I just go ahead and surprise everyone with how well it works?

• 0:45Speaker 01

  There's no way. That's gonna fizz, surely.

• 0:47Speaker 00

  You think so?

• 0:47Speaker 01

  Yeah.

• 0:48Speaker 00

  I shook it really a lot.

• 0:50Speaker 01

  I mean, that was intense. I'm gonna move my laptop out of the way.

• 0:54Speaker 00

  Move your laptop out of the way, but I trust the science. Okay, you ready?

• 0:58Speaker 01

  Yeah, go on.

• 1:02Speaker 00

  Okay.

• 1:02Speaker 01

  Okay, compared to what I was expecting...

• 1:03Speaker 00

  Compared to what you were expecting, wouldn't that have been even cooler if it didn't make any noise? But I mean, that's not too bad.

• 1:10Speaker 01

  That was amazing!

• 1:12Speaker 00

  Do you know why that works?

• 1:14Speaker 01

  Do you know the phrase that, um, that some people, I don't know if you'll have this in America, but the phrase that's used to describe what you just witnessed there is a nun's fart. Do you know this?

• 1:25Speaker 00

  No!

• 1:28Speaker 01

  Am I the only one who's heard that phrase?

• 1:30Speaker 00

  What does a nun's fart mean?

• 1:31Speaker 01

  You've heard that phrase. You've never heard that phrase. Yeah, like...

• 1:37Speaker 00

  Like, it's not good, but it's not as bad as it could have been.

• 1:40Speaker 01

  It was just like a really gentle release of air.

• 1:42Speaker 00

  Oh!

• 1:44Speaker 01

  Like, it wasn't like, it wasn't aggressive.

• 1:47Speaker 00

  I get it, but I think nuns should feel comfortable flatulating however loudly they want.

• 1:53Speaker 01

  Okay, so I had this friend, when I was at uni, a friend who was studying to be a medic, and they were like top of their class, aced it, aced it, aced it, aced it. And the consultant in the hospital who they were working under came to find them one day because they were like, "I've got a genuine treat for you. There is a nun who needs to have a rectal exam."

• 2:11Speaker 00

  Oh!

• 2:12Speaker 01

  Right? And that is how you stun Michael Stevens in silence.

• 2:16Speaker 00

  That's how you leave me with nothing to add.

• 2:26Speaker 01

  This episode is brought to you by Cancer Research UK.

• 2:29Speaker 00

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• 2:40Speaker 01

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• 3:18Speaker 01

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• 3:30Speaker 02

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• 5:03Speaker 01

  I think that's quite interesting scientifically, personally, but okay, maybe that's...

• 5:06Speaker 00

  Are you saying that nuns actually have great farts?

• 5:10Speaker 01

  Yes.

• 5:10Speaker 00

  Like gentle farts?

• 5:11Speaker 01

  Like gentle fart.

• 5:12Speaker 00

  I guess I could believe, I don't want to stereotype nuns, though.

• 5:15Speaker 01

  Okay, look...

• 5:16Speaker 00

  Like, if you're a nun who listens and this is bothering you because you think your farts are a little, like, louder or smellier than they should be, it's okay. You're still a valid nun.

• 5:28Speaker 01

  Oh, I'm not, I'm not commenting on the smell. I'm merely commenting on the...

• 5:32Speaker 00

  I'm commenting on the smell.

• 5:33Speaker 01

  Okay, okay. But is it real? I can see Lauren in the corner of my eye.

• 5:37Speaker 00

  Okay, so our fact-checkers are saying that a nun's fart is not a thing.

• 5:41Speaker 01

  I'm sorry, I'm...

• 5:42Speaker 00

  That you have created this in your own mind as a saying.

• 5:46Speaker 01

  No. Look, when you open a bottle of champagne and it goes, "Ooh", then you say, "Oh, like a nun's fart." I didn't make this up. Look, I'm not an expert here. I'm sure that people in the comments with opinions. Look, if you happen to be a sort of a colorectal surgeon, and you've got, you've got evidence, then we want to hear it.

• 6:07Speaker 00

  Let us know. Do nun's farts earn their name as a nun fart? But look, why, why does the tapping the sides work?

• 6:16Speaker 01

  Right.

• 6:17Speaker 00

  Well, at the end of the day, here's what's happening. When you've got the liquid in the can, I'll pour it into this cup so we can look inside.

• 6:24Speaker 01

  Yes, please.

• 6:24Speaker 00

  When you shake it up, the carbon dioxide gas that's dissolved in the liquid

• 6:29Speaker 01

  Mm-hmm.

• 6:31Speaker 00

  collects on little imperfections on the glass.

• 6:33Speaker 01

  Yes, stuck to the side.

• 6:35Speaker 00

  Mechanically gets stuck onto these sides. So if I like, I don't know, I'm trying to make this like shaky, but you'll notice that you get bubbles on the outside. When you then release the pressure at the top, those bubbles along the sides expand rapidly, and that creates the foam. That creates the geyser that comes out. But if you tap the sides, and you can try this with a clear glass, you can watch that when you flick the sides, the bubbles get released and then go up to the top.

• 7:02Speaker 01

  Right.

• 7:03Speaker 00

  So all that gas that came out when I shook the can, still out of the liquid, but it's all collected at the top of the can. So when I open it, the gas all comes out, but no foam and liquid does too.

• 7:15Speaker 01

  So essentially, you're getting rid of the nucleation sites on the side?

• 7:18Speaker 00

  Well, the nucleation site is still there. It's just there's no more gas caught on that site because you flicked the bubbles off the site and they floated to the top.

• 7:28Speaker 01

  Amazing.

• 7:29Speaker 00

  If you tap the top, you're not cleaning the bubbles off the sides. The vibrations might still cause some bubbles to leave the side, so it's still better than nothing. But the sides and even the bottom is what you want to do. You want to clean them so there's no gas mixed in and in bubble form in the liquid to then expand and bring the liquid up with it.

• 7:48Speaker 01

  Got you. Okay, well, this is a good trick. This presumably works for any drink that has got carbon dioxide dissolved within it.

• 7:56Speaker 00

  Correct. The only other solution is to just wait. If you wait like 10, 20 minutes, the gas will re-dissolve back in and you can open it without an explosion.

• 8:07Speaker 01

  So I see why it fizzes up. I understand that, right? That you've got like little pockets of air that are rapidly expanding and thus causing all this foam. I get that. I think what I'm asking is, why does the act of shaking, what does the act of shaking physically do to the contents of the, inside the can?

• 8:26Speaker 00

  Clearly, you're not adding anything to the contents by shaking. But I guess the gas, when it's dissolved, takes up less room. And then once it leaves as a gas and like the molecules stick together...

• 8:41Speaker 01

  When you open a can, the liquid is not like right at the very top, is it? There's like a little gap.

• 8:47Speaker 00

  Yeah, there's, there's a little bit of air. That's why you can take a full can and you can hear it slosh in there.

• 8:51Speaker 01

  Right, so you're taking the air and mixing it in to the liquid, I guess. The air that would sit at the top. There's a little layer of air. As you shake it, that air gets mixed in with everything else.

• 9:03Speaker 00

  I couldn't really describe it. I don't totally know why a mechanical, like nucleation site, an imperfection in the metal, a scratch, causes the gas to appear out of the liquid. Same with why a Mentos dropped into Coke. Mentos is just somehow covered in nucleation sites and just an enormous amount of gas gets produced. But I don't know why.

• 9:27Speaker 01

  It's just really hairy. Mentos is just really, really sort of has all of these little air pockets in it.

• 9:33Speaker 00

  But why is it that when this hairy surface comes into contact with a gas dissolved in a liquid, the gas goes, "Whoa, I'm out"?

• 9:41Speaker 01

  Yeah.

• 9:42Speaker 00

  I don't know.

• 9:43Speaker 01

  Well, I think, I think that is just because carbon dioxide is really unstable. And so it kind of kickstarts it. But there's different ways, right? Because there's dissolved as tiny air bubbles that are just separated and suspended within the liquid. And then there's dissolved in the sense of it's no longer just carbon dioxide, it's a new molecule. Tell you one more thing about Coke cans. Have you noticed how you can stand on a full Coke can, but on an empty one, it crushes under your weight?

• 10:13Speaker 00

  That makes sense, though, right? Like, I can't crush the full can because I can't compress the water.

• 10:18Speaker 01

  Right, because there's pressure inside it.

• 10:20Speaker 00

  Yeah.

• 10:21Speaker 01

  Whereas when you release that pressure...

• 10:22Speaker 00

  It's so much stronger.

• 10:23Speaker 01

  Right. Okay, so here's the thing about aircraft. Same story. Inside an aircraft, it's so much stronger when it's pressurized within than if you have like an open fuselage. It's also much more comfortable.

• 10:38Speaker 00

  Right.

• 10:38Speaker 01

  You can effectively be, your body can effectively be at, you know, 5,000 feet or whatever it might be, while you're physically much higher in the atmosphere. The only thing about this, right, is that if you imagine like... Releasing all the pressure and then blowing it up again and then releasing all the pressure and then blowing it up again and then releasing all the pressure and then blowing it up again. Um, yeah, it ends up with like a bit of a mess.

• 11:01Speaker 00

  Yeah.

• 11:02Speaker 01

  And it's the same thing with aircraft. You have to be really careful because you're inflating it, deflating it, inflating it, deflating it all the time.

• 11:10Speaker 00

  Right.

• 11:11Speaker 01

  Uh, and a lot of the skin of aircraft, particularly older designs of aircraft, is panels, metal panels. I think it is actually aluminium, some of it.

• 11:21Speaker 00

  Hmm.

• 11:22Speaker 01

  Um, these aluminium panels that are riveted onto this surface into this structure. And so as a result, you have to be extremely careful about how far you inflate the fuselage of your aircraft so that you don't end up causing structural damage like this. However, this is the reason why one aircraft is way superior to every other.

• 11:42Speaker 00

  And I was on one of them on my flight out here.

• 11:45Speaker 01

  Were you?

• 11:45Speaker 00

  Cause you told me if they have the windows that like.

• 11:48Speaker 01

  Yes.

• 11:49Speaker 00

  Uh, magically change.

• 11:51Speaker 01

  Yes.

• 11:51Speaker 00

  What, they, they become darker.

• 11:53Speaker 01

  Yes.

• 11:53Speaker 00

  You don't have a window shade that I was on the right kind. And yeah, it did, it just felt wonderful.

• 11:58Speaker 01

  Okay. Should we have a little break? Go on to the questions?

• 12:00Speaker 00

  Yeah.

• 12:01Speaker 01

  All right, let's do it.

• 12:15Speaker 00

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• 13:50Speaker 01

  Okay, should we do some questions?

• 13:52Speaker 00

  Let's do it.

• 13:52Speaker 01

  Right. Here's one from Benjamin on email. Benjamin says, ever since I was little, I have held science and scientists in the highest regard with an almost religious amazement, admiration and trust. Over the past five or six years though, as I learned more about things like replication crises and counterproductive incentives, in the funding and publication processes, I find it harder to trust the scientific establishment and related media and government organisations. So, my questions. Practically, how do I know when and if I cross the line from healthy skepticism to paranoia? Emotionally, how can I deal with the feeling of my faith in science being shaken?

• 14:31Speaker 00

  What a great question. Yeah.

• 14:34Speaker 01

  I've actually been thinking about this a lot recently, you know, like a lot. And I don't have a firm answer, but I have thoughts.

• 14:40Speaker 00

  Okay. Yeah. What do you think? Because first of all, I'd say as soon as you have a religious faith in something, you've set yourself up for a problem, especially if that something is not an actual god.

• 14:52Speaker 01

  Right.

• 14:52Speaker 00

  Scientists are people.

• 14:54Speaker 01

  Mm hmm.

• 14:55Speaker 00

  And scientific progress, as Planck told us, happens one funeral at a time.

• 15:01Speaker 01

  Yes.

• 15:02Speaker 00

  Okay.

• 15:02Speaker 01

  Yes.

• 15:03Speaker 00

  So, yeah, humans are wrong. Scientists try their best, but we all have biases, we all have prejudices, and that comes through even in science, even in math.

• 15:14Speaker 01

  Hmm. Yeah. Well, we should probably say what the replication crisis is for those who, uh, haven't been following every twist and turn of scientific, sort of kind of common subjects in science in the last, uh, the last hour long.

• 15:25Speaker 00

  Well, yeah, a lot of, a lot of psychological experiments from decades ago that became staples of textbooks that we all just accepted as like, yep, that's what people do. That's how we behave. That's how we perceive have not been replicated since they were first put down in those textbooks. We've revisited them lately and been like, oh yeah, let's try this study. Let's see if this is really how people, um, assign motivations to each other. And it just isn't.

• 15:54Speaker 01

  Right.

• 15:55Speaker 00

  This one study that was done on like 12 college kids in 1957, did not, as it turns out, completely explain all of human behaviour.

• 16:05Speaker 01

  Exactly. I mean, surprise.

• 16:07Speaker 00

  Yeah.

• 16:08Speaker 01

  But it's not only, it's not only because it was something really fundamental about the way that science was structured. Because the problem with, you know, if you are looking at where stars are in the sky, or like ca- coming up with a precise calculation about the way that spacetime warps with two black holes, you are, you are within a very narrow window.

• 16:30Speaker 00

  Yeah.

• 16:31Speaker 01

  You can make your measurement, you can come to conclusions, you know, with, with some confidence that what you are saying is correct. When you are dealing with people, it's a whole different game, right? You are, this messy is all over the place. People don't give you the same response two times in a row and so on and so on and so on. And so as a result, what scientists did is they said, okay, we're going to draw a line in the sand. And if we would expect to see this evidence, if it was just a complete fluke, less than one in 20 times, then that's good enough. That's evidence for us. So the example that I like to give my students is, um, gingers are about 1% of the population. Okay?

• 17:13Speaker 01

  If you have two gingers in a room, like that's pretty suspicious. Okay? If you start to get like five gingers in a room.

• 17:19Speaker 00

  Right.

• 17:19Speaker 01

  Something's going on.

• 17:20Speaker 00

  Yeah.

• 17:21Speaker 01

  So, uh, what science did is they worked out a way to say, if something is so unlikely that there must be something going on that you could, you're like, okay, I'm really suspicious now. They worked out where to draw that line. And the line that they drew was they said, we will accept one in 20, right? That's, that's kind of where the line is.

• 17:39Speaker 00

  Yeah.

• 17:40Speaker 01

  The only problem is that when you add in the whole of scientific, the sort of scientific establishment, like people trying to get grants, people trying to get things published, you know, if you try something 20 times, that means just by fluke alone, one of them is going to look like a real result when it isn't. And then if you have an entire population of scientists who are just trying this, try this, try this, try this, try this, try this, try this, it means that so many of these fluke results, that's just like, sometimes you're just in a room and there's five gingers, you know? So sometimes that just happens.

• 18:16Speaker 00

  Sometimes you're in Ireland, okay?

• 18:17Speaker 01

  Sometimes you're in Ireland, exactly.

• 18:19Speaker 00

  And like, yeah, I think so much of, I, I put a lot of the blame on the fact that the actual research, the actual papers are usually behind a paywall. It's completely obnoxious that I'll hear about something, I'll read an article from The Guardian, and they will say, whoa, you know, within a 95% confidence interval, like, this is causing this. And I'm like, wow. But then I find the paper and I can only read the paper if I pay $98 per month and I subscribe to this service.

• 18:52Speaker 01

  Yeah.

• 18:53Speaker 00

  So I will illegally get the paper. I'll read it and the paper does not make the claim that the article made.

• 18:59Speaker 01

  Yeah.

• 19:00Speaker 00

  The paper says, well, we were really interested in this one really specific thing and we wanted to add some data and we tried this and there's all these other reasons that could be explaining it, but it seems like this might be in favour of this, but we need at least 2,000 more data points.

• 19:14Speaker 01

  Mm hmm.

• 19:14Speaker 00

  And I'm like, this is science.

• 19:16Speaker 01

  That's science.

• 19:17Speaker 00

  But it gets filtered down to the rest of us as, whoa, green M and M's are poison.

• 19:24Speaker 01

  Right, exactly.

• 19:25Speaker 00

  But when you read the paper, the paper is like, green M and M's are not poisonous. However, there is a weird thing that's statistically happened in this one study that we did and we wanted to show the method so that other people can learn from this and do more studies. And that's all it says.

• 19:39Speaker 01

  Right, right. Totally agree. But so there was this, I mean, they called it a crisis, the replication crisis, where suddenly psychology in particular, but other subjects too, looked at everything they had and were like, okay, hold on a second. How much of this stuff is actually real? Like, how much of this stuff is just flukes that we have published? Because it sounds, because of course it's publishing the most interesting things, publishing like the most kind of strange results. Um, and a lot of science did fall. A lot of science fell. I mean, mostly it was at the sort of more humany end of things. Um, psychology, some, some sort of, um, like medicinal studies as well, right? Um, but, uh, things like maths were absolutely fine. Uh, physics was largely untouched. And I think that what this

• 20:23Speaker 01

  does for me is it reiterates what science should really be, which is it should be an engine of doubt.

• 20:33Speaker 00

  Right, exactly.

• 20:34Speaker 01

  It should be that at the centre of science, the thing that drives progress forward is intelligent doubt. It's continually asking more and more questions, continually wondering if there's more, continually trying to find out more. And so I think that actually, science as a whole is really one of the only institutions that we've ever created as humans that has worked out how to turn doubt into something incredibly positive. I mean, there's a couple of others, right? Like the airline crash report industry is pretty good at it too. But I think science is really good at like continually questioning itself. Scientists?

• 21:17Speaker 01

  Not so much. Science? Much better.

• 21:20Speaker 00

  Wisdom of the crowds.

• 21:21Speaker 01

  Right.

• 21:21Speaker 00

  You get one scientist, you've got one person.

• 21:24Speaker 01

  Mm hmm.

• 21:25Speaker 00

  If you get a thousand scientists, you've got a whole new super organism.

• 21:30Speaker 01

  Mm hmm. The final thing I would say about all of this though, is that, that comparison that was made between having faith in science and sort of having a kind of religious faith, I do also think, and I say this as somebody who's brought up Catholic but is no longer religious at all, I think it's really easy to assume that, oh, I've left faith behind because I'm no longer religious. I have science, that's what I believe in. I actually think that we're kidding ourselves if we.

• 22:04Speaker 01

  Make that assumption. If we try and claim that modern society isn't held up by faith at every conceivable level, I think we're really fooling ourselves. You know, I believe in science too, right? But I also know that science itself takes quite a lot of faith. Like, why is the speed of light an absolute limit? Like, why that number? You know, what happened before the Big Bang? Like, there's, there's certain elements of, I mean, there's all kinds of elements of science that I don't personally know or understand, but I have to like have faith that the people who do understand it, understand it themselves. You know, all, all I think that you're doing, if you believe in science as opposed to believe in religion, is I think that you've just got a different starting point for your faith.

• 22:47Speaker 00

  Yeah, right. You take some different things to be sacred and beyond question. And that can get dangerous when you're like, ah, no, I'm going to support this particular scientific hypothesis because it's like my favorite sports team and I'm just all in it for that reason. And I'm going to pretend like you're unscientific for questioning it. But you're right, there's a kind of intelligent doubt that isn't just a, I don't believe it unless it's what I want to believe. That's, that's not intelligent doubting. But there's a kind of, let's question this and really be sure. How can we really be sure if this is true, then this other thing shouldn't be true? Let's test that. It's a process.

• 23:30Speaker 00

  Science is a way of knowing. It's not the same as knowing through revelation. Oh, I was told in a dream, or, well, this old book says so. I also think that science and religion aren't a one or the other thing.

• 23:47Speaker 01

  Non-competing majesties.

• 23:48Speaker 00

  Yeah. I think that they are co-monarchs and they both have an element of each other in them.

• 23:56Speaker 01

  Yeah, I think you're probably right. Anyway, sort of gone full circle back to nuns, haven't we?

• 24:02Speaker 00

  Yeah, we have.

• 24:04Speaker 01

  Next question. This came in from Vikram, who says, I've always been fascinated by Archimedes' famous quote, "Give me a place to stand and a lever long enough and I will move the earth." I was wondering how literally this can be interpreted from a physics perspective. If we can imagine an impossibly strong, perfectly rigid lever with a fulcrum somewhere outside of Earth, could this actually work in theory?

• 24:28Speaker 00

  No, not, not the way you're describing it, but also not even in any, in any way. Like, I love that idea, right? Like, a lever amplifies force so almost magically that we can use levers to lift a car, right? And so Archimedes was like, wow, I could lift something as heavy as the planet Earth if you gave me a lever long enough. And that whole quote is like this real triumph of, of science and engineering over nature, right? Give me a lever long enough and I will move the world. But Vikram, in the question, says,

• 25:08Speaker 00

  if I had like a, an infinitely strong, perfectly rigid lever, boom, you've already lost. The lever cannot be totally rigid. If it was totally rigid, one, it would violate physics completely, because that would mean that moving one end would cause the other end to move instantaneously. So you would be sending information through that lever faster than light. I can't describe this in all the detail that I want to, because it's the topic of my next long video.

• 25:39Speaker 01

  Right. I know you've been playing with levers for a while.

• 25:42Speaker 00

  For a long time, yeah.

• 25:43Speaker 01

  I've seen, I've seen into your workshop and there were levers all over the, all over the place.

• 25:48Speaker 00

  And pendulums and hoops and discs. But the point is, we don't even need to focus on that right now. The problem is, okay, so you want, you want to lift the world. First of all, against what? Like, the Earth can't be put on a table, because a table, large enough to hold the Earth, would collapse into a planet itself. All right? So whatever. But that's, that's just kind of a joke. The point is, if I want to lift something arbitrarily heavy and I have a surface to do it on, the other problem you get is that the lever itself winds up having to weigh so much that, and I saw, oh man, there's a great video where

• 26:32Speaker 00

  someone broke this down. And they were like, to lift the Empire State Building with a sheet of paper, you would need a lever made of more matter than the entire planet Earth or something.

• 26:44Speaker 01

  Wait, with a sheet of paper? I don't understand.

• 26:47Speaker 00

  So you, you've got a fulcrum right next to the Empire State Building and a lever and a beam that goes underneath the building. And then it goes really long out the other way. So you can just drop a piece of paper on that end and it lifts the Empire State Building. The problem is, levers themselves also have weight. And so, just by installing that lever, you're going to start lifting the Empire State Building because of the mass of the lever beyond the fulcrum. This was a problem that I had with one of the levers I built.

• 27:18Speaker 01

  It was so big, it left the, it had its own gravitational pull?

• 27:21Speaker 00

  No. It was, it was just so big that it lifted everything because it was already so big. And I'm like, no, no, no, I want to be able to push. So I had to make the lever smaller and less effective.

• 27:33Speaker 01

  Right.

• 27:33Speaker 00

  So that I could actually have a role in the lifting. To basically answer your question, in a way, lifting the world with a lever is a great way to describe how mechanical advantage has like no bound. But yet it does, even theoretically, a lever that long, if it was rigid, it would not work as a lever. It would be a physically impossible object. Maybe we just kind of leave it there.

• 28:00Speaker 01

  Here's what I'm hearing. Archimedes was an idiot. That's a...

• 28:04Speaker 00

  No, he wasn't. I love, I love.

• 28:06Speaker 01

  I'm hearing loud and clear, Michael.

• 28:08Speaker 00

  I love the like, how that teaches leverage and, and imagination. But it just falls apart as an actual experiment we could do, even in our own minds.

• 28:22Speaker 01

  I also think if you were capable of building a sort of impossibly strong, perfectly rigid lever and installing a fulcrum somewhere outside of the Earth, I would say you're, you're putting your effort into the wrong thing.

• 28:36Speaker 00

  You could have built, I don't know, a giant pair of sunglasses to put around the sun.

• 28:42Speaker 01

  Now we're talking.

• 28:43Speaker 00

  Right?

• 28:44Speaker 01

  Now we are talking.

• 28:45Speaker 00

  You could have built a skyhook or, or.

• 28:49Speaker 01

  Space elevator, you know, there's, there's other things. Okay, here we go. Last question. This is from Nils Moody on Reddit, of course, with a name like that. What is your strategy when curiosity and wonder seems to dwindle?

• 29:03Speaker 00

  Oh, do you have an example of when that would happen? I think there are people on Earth who have a lot of influence, but have no curiosity.

• 29:13Speaker 01

  I agree with that.

• 29:14Speaker 00

  But are there times when all of us as a society don't have enough curiosity?

• 29:21Speaker 01

  Gosh, that's such an interesting way of thinking about it. The way I took that question, on the surface was within you as an individual, right? And I was thinking, well, yeah, when I'm really tired, or like when there's lots of stuff going on.

• 29:36Speaker 00

  Right.

• 29:37Speaker 01

  But I love the idea of thinking of it at a society level. I think, you know what, actually, I think that this does link back to that first question about doubt. I think that, for me, doubt and curiosity are really, they sort of go hand in hand in a lot of ways. When you think that there is always something more to discover, you're kind of like insatiable for the next thing. I think that's sort of how curiosity appears. And I think there have been times in the past, historically, when doubt, self-doubt in sort of societal, cultural decisions has gone down. And I think curiosity goes down at the same time, you know? I'm thinking about really bad, I've got bad, bad things in my head

• 30:21Speaker 01

  here. But I think when you're really certain that another people, another country, another whoever, are whatever story you want to tell yourself and don't have curiosity for who they actually might be, I think that's when doubt's gone down.

• 30:35Speaker 00

  I think you're right. Cause what I'm thinking of are two books. One is Hannah Arendt's Oh, yeah. Life of the Mind. The very first chapter in that book, she talks about evil being such a, a non-storybook thing, that it's just flat out.

• 30:54Speaker 00

  Thoughtlessness. I'm not going to question this. It is what it is. And then I just, I just finished reading Perfect Soldiers, which is a book about the, the life stories of the nine 11 hijackers. And that guy's like, right off the bat, he's like, okay, I've studied everyone involved. And like, the one thing they all had in common was certainty. They were certain that what they believed was the only correct answer.

• 31:23Speaker 01

  Gosh, that's so interesting.

• 31:24Speaker 00

  It wasn't, it wasn't any particular religious or political belief. It was their certainty in the belief.

• 31:33Speaker 00

  And he's like, that's always the problem. That's all I have to say about this.

• 31:36Speaker 01

  That's amazing. I sat next to dinner once to a guy who was really high up in the Red Cross. And it would be his job to go into war zones and to negotiate with people who, you know, who were even committing genocide, right? Like really horrific, horrific stories with horrific people. And it was his job to go in and negotiate with them to allow access for the Red Cross, to give aid to, to whoever needed it, regardless of what side they were on. And he said something really interesting, which is that in order to make a soldier, in order to make it so that a human is capable of committing those acts on another human,

• 32:20Speaker 01

  you really only have two choices. Either you have to psychologically mess them up so much. So this is like the child soldier thing that happens in places around the world where you, you expose them to such brutal acts that you deliberately psychologically damage them, turn them into madmen, essentially. That's one route. Or the other route is that you turn them into machines, you turn them into robots. And for that type, this is the, um, you know, the sort of marching like, this, that, this, that, this, that, this, that, right? You take your gun, you strip it down, you put it back together, you strip it down, you put it back together, you strip it down, you put it back together, you strip it down, you put it back together, like over and over and over and over again,

• 33:05Speaker 01

  until the act disentangles itself from your consciousness of the act itself. So that you are completely robotic in your actions. The other thing he said that really stuck with me was that when you get inside, and he had met some horrific people, like really big, sort of famous names of like tyrants, like horrific people. And he said that when you, when you get in there, there's one they described as like this palace and it was like Mad Max, all of these unbelievably expensive vehicles. And they were basically committing genocide. I mean, they actually were committing genocide. And he got into layer and layer and layer and layer.

• 33:47Speaker 01

  And once he got in, he was like, it was just a really sad little man.

• 33:52Speaker 00

  Yeah.

• 33:52Speaker 01

  Inside, the most horrific people you can imagine. He was like, it was actually, actually just a sad little man.

• 34:00Speaker 00

  So what do you do when people become sad, little incurious people? I don't know. I feel like you need to allow more modes of thought and action. Don't circumscribe people. Allow them to go, oh, I have the freedom to be different than that. Like, I think a lot of the things that we today have less of are like ways of life. There's like one option. For example, not even, just a few decades ago, selling out used to be a major problem. But today, the more ads and brands you have, the better you're doing.

• 34:43Speaker 00

  Get that bag. Like, no, because, because what else are you supposed to do? If you're a band, where do you put your music except one of the major streaming platforms? Like, yeah, you could, you could press your own vinyls and like hand them out on the street. But we've just become so stuck into having only those options that I think we just accept them, that we become, we say, well, that's, it's sacred. We don't even, we aren't even curious about what other options there could be. And so unless we, as a society, allow people to explore weird things out beyond the pale, we will become less and less curious.

• 35:23Speaker 01

  This answer brought to you by.

• 35:26Speaker 00

  This answer brought to you by the curiosity box.

• 35:31Speaker 01

  I mean, that, this went in a dark direction, didn't it? This went in a very different direction.

• 35:35Speaker 00

  I think it went in a dark direction, but it found a little bit of light in the darkness.

• 35:41Speaker 01

  Yes, I think so too.

• 35:43Speaker 00

  And that light is known as an annual membership to the curiosity box.

• 35:48Speaker 01

  I think, I think you're right though. It's like, it's the opposite of what the Red Cross guy said. You don't want to end up being robotic. You don't want to end up in a situation where you're following action after action, after action, after action, without any curiosity about why you're doing it or whether you should be doing it. I think it's about really recognizing that you can choose your own path. And I think that actually having curiosity about ideas, curiosity about science, about philosophy is a really good way to start.

• 36:22Speaker 00

  Because the thing, selling out doesn't mean selling stuff that you make. It means changing your values because you got paid some money. So if we, if we made our own merch, like that's not selling out. But if we started selling RFK Junior's book to science, then we've like abandoned our principles.

• 36:47Speaker 01

  I do think that a society is healthier and bluntly happier when they ask more questions, when they are more curious. And I think that in the tiniest possible way, that we can contribute to a culture which allows room for that. I do actually bluntly, maybe this is just on my bad days when I want to like, feel like I'm doing something good for the world. But I do actually think a little bit that the stuff that we do does do that a tiny bit. You know, like, we make silly little Instagram shorts that, um, aren't important, don't change the world, but they're better than the slop that's out there.

• 37:29Speaker 00

  I don't know. I think they can change the world. I think they're part of the world. Even if they're silly and small, that's what the world is. It's a bunch of silly and small stuff. And at the very least, we're kind of putting out another perspective. You know, another, another little hook that makes things less smooth and makes it more curious. But it can't just be us.

• 37:57Speaker 01

  Can't just be us.

• 37:58Speaker 00

  Yeah, it has to be you.

• 38:01Speaker 01

  And your questions, which you reliably send us in to the rest of science at gohangar.com. And we enjoy every single one of them.

• 38:08Speaker 00

  And we enjoy all the questions on the subreddit. And you guys have these conversations about them. And they can be about the most trivial things, but yet the act of talking about them is not trivial at all. That's like community. Exactly. So thank you.

• 38:26Speaker 01

  Yeah, genuinely. Thank you. And we will see you next week.

• 38:42Speaker 04

  Everyone's got a hard question about AI. Your job, your kids, where it's going. Anthropic was built to surface those questions and share what it finds along the way. Because there's hope in hard questions. Ask yours at claude.ai/spotify and keep thinking. That's claude.ai/spotify.