The Lake At The North Pole That Stops Europe From Freezing

When you picture the North Pole, you probably imagine a vast, frozen expanse of floating sea ice. But hidden deep beneath the surface of the Arctic lies something incredible: a massive, churning reservoir of nearly freshwater, suspended right in the middle of a saltwater ocean. In this episode of The Rest Is Science, Professor Hannah Fry and Michael Stevens (VSauce) explore the hidden hydrodynamics of the Arctic. Fresh off a real-world scientific expedition to the sprawling ice sheets of Greenland, Hannah shares firsthand accounts of the colossal forces currently reshaping our polar regions. Together, they unpack the bizarre physics that allow a gigantic freshwater lake to form beneath the Arctic ice. Fancy some some of your own glacial water? https://svalbardi.com Send questions of your own to [email protected] or find us at r/TheRestIsScience. ------------------- 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 Chief Digital Officer: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

• 0:01Speaker 00

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

• 0:05Speaker 01

  And I'm Hannah Fry.

• 0:06Speaker 00

  And today on this episode of Field Notes, I have no idea what's going to happen because it's Hannah's turn to report back from her expeditions in life. What have you, what have you got?

• 0:17Speaker 01

  Do you know what expeditions is, is exactly the right word for, for today's episode? Because, because I've just got back from the Arctic and I sort of don't want to, I've changed my camera position around here because all of my, sort of, my thermal wear is laid out across the floor behind me. I sort of want to kind of hide it.

• 0:39Speaker 00

  Also, you're trying to hide your floor.

• 0:41Speaker 01

  And just, I'm hiding my floor. It may, it may peek into view at certain points during the course of this, this episode. And, but I brought you back, I brought you back something pretty exciting from the Arctic, Michael, which is, which is today's, today's subject of conversation, which is a little bottle of water from the North Pole.

• 0:59Speaker 00

  Oh, wow.

• 1:00Speaker 01

  Isn't that cool?

• 1:01Speaker 00

  Okay, so what's the North Pole like right now? Was there liquid water there? Or was it an ice sheet?

• 1:06Speaker 01

  No, I didn't actually get to go to the North Pole.

• 1:08Speaker 00

  How high did you go?

• 1:09Speaker 01

  Ah, I went, let me see, I went seven.

• 1:12Speaker 00

  Hold on, I need to stop using this northern hemisphere centric language. How far north did you go?

• 1:20Speaker 01

  Yes, not about how far up. Let's, uh, let's, let's not be biased here. Um, okay. So I was on an icebreaker, um, that was setting off for an expedition to the North Pole. Uh, and I met up with them in Svalbard. Um, and they, they left as I was there. I sort of waved them off from the dock. Um, so this was their previous, previous, uh, expedition. It's the, it's the Norwegian Polar Institute. Because the thing is, right, when you, I mean, I was going to film this program that I'm, that I'm doing, right? And that they've got their own stories. Yeah. But when you go to like these unbelievable places, you find out so much more stuff than you can possibly ever fit into a TV program, right? And so

• 2:01Speaker 01

  what I thought I would tell you about today is, uh, this, this like wild thing that I discovered that I had absolutely no idea about, um, while I was up in the Arctic. Um, because if I, if you drank this little bottle of water that had been collected from underneath the ice sheet, uh, at the North Pole, what do you think it would taste like? That's my question for you.

• 2:22Speaker 00

  Good question. So my first thought is salty.

• 2:24Speaker 01

  Hmm, wrong.

• 2:26Speaker 00

  Really?

• 2:27Speaker 01

  Totally wrong.

• 2:28Speaker 00

  Is it fresh water? Because of what? Because it's melted ice?

• 2:32Speaker 01

  Okay, yes, and yes. And there's so much more to it than this. And I had no idea about this at all until I, till I sort of went up there to go and see.

• 2:48Speaker 01

  This episode is brought to you by Cancer Research UK.

• 2:51Speaker 00

  Do you remember when we discussed why feet are so weird? Well, one particular foot bone holds an even stranger surprise. It's helping shape our understanding of cancer timelines.

• 3:02Speaker 01

  And for that, we're going to need to go all the way back before Neanderthals even existed to a 1.7 million year old foot bone. Researchers have identified a tumor in it in the oldest known example of cancer in people.

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• 3:47Speaker 01

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• 3:57Speaker 02

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• 4:29Speaker 03

  This episode is brought to you by Michelob Ultra. Good times mean competitions between you and your friends, like seeing who can throw some pigskin the farthest or rush the field the fastest. Winner gets an ultra. Because it's not just a superior light beer, it's also giving fans superior access to their favorite sporting events. Superior is worth playing for. Visit michelobultra.com/superioraccess to enter. Enjoy responsibly. Copyright 2026 Anheuser Busch InBev Michelob Ultra Beer, St. Louis, Missouri.

• 5:04Speaker 01

  So, okay, fine. When rain comes down, you know it's fresh water. When it freezes as snow, you know that's fresh water too. Fine. But here's the thing, when seawater gets really cold, cold enough to freeze, when it's about minus 1.8 degrees C, the water molecules, they start locking into this, this rigid crystal lattice. But this geometric structure doesn't have any space for the salt ions. So it just kicks them out. It kind of just kicks them out farther and further and further. And then, uh, what you end up with is like the ice that is floating on top of the sea is like fresh. You can take a chunk of older ice and, and drink it. Um, and there is one company that I came

• 5:47Speaker 01

  across that is now actually selling this as though it was sort of wine. It's unbelievably expensive, the prices that they're, they're selling this for.

• 5:55Speaker 00

  Svalbardi, the water.

• 5:57Speaker 01

  Polar iceberg water. Uh, what they're saying here is this is pristine ice. It's sort of, it's been locked up for millennia sometimes. Um, fresh as the day it fell as snow. So, so they, they gather it, they melt it, and then they sell it for, hang on, let's just get up the, the live prices right now, for a single bottle, right? 750 milliliter bottle of water, Michael, 100 euros.

• 6:23Speaker 00

  I've got a few questions. They are melting icebergs to make this water?

• 6:29Speaker 01

  Yes.

• 6:30Speaker 00

  Okay, so the water maybe has been in that iceberg for a long time. Cause my first thought is, well, look, I'm going to flush the toilet after this podcast. Eventually, some of those molecules will be at the North Pole. Like, it's a whole water cycle, guys. It's not special water up there. It's every molecule gets its turn. Every drop gets its turn up there. Uh, but if it's trapped in ice, then it can spend a lot longer somewhere or not somewhere. So this is water that it, they, they say on the website that they're collecting it just before it melts away forever.

• 7:05Speaker 01

  Right.

• 7:06Speaker 00

  It's pristine ice locked up for millennia and fresh as the day it fell as snow. Now, it's, it's, I wouldn't say it's fresh. I think the process of turning into glacial ice takes long enough that there's going to be some dust. There's going to be some bacteria cell walls in there. But anyway.

• 7:26Speaker 01

  A little mammoth hair every now and then.

• 7:27Speaker 00

  Oh, a mammoth hair would be really cool. So you don't have one of these, but you do have an even more rare kind of water, which was collected by the Norwegian, what?

• 7:35Speaker 01

  It's the Norwegian Polar Institute, but this is actually from the North Pole, like for real, for real, for real, the North Pole.

• 7:41Speaker 00

  Not just 78 degrees north, but 90.

• 7:44Speaker 01

  Exactly. Anyway, so here's the thing about this fresh water. Okay. So, um, the, for, for thousands of years, the, the Inuit people have, have known, the indigenous people of the Arctic, they, they've known that you can eat sea ice and it's fine, right? It is, it will hydrate you properly. Um, but, uh, but it all depends on what it looks like, right? So if it's first year ice, if the, if the ice is really flat and it's a little bit gray and it's got these sharp and jagged edges, then don't. But if the ice is thick, if it's sort of multi-year ice, um, if it's more rounded at the edges, also if it glows slightly blue, then you're fine. Because by that point, the salt within it will have been squeezed out by this process of sort of melting and then refreezing or slightly

• 8:29Speaker 01

  melting around the edges and then refreezing, um, in summer and winter. What was really funny about this though, because when, when Europeans started like pushing up in the north, uh, in the Arctic in the 16th century, uh, especially when they were looking for the Northwest Passage, the way to connect Europe to the Americas, uh, what they were doing, they, they had no idea that, that they, they knew you could eat, uh, snow, fine, because that's fallen as precipitation. But they did not know that sea ice would, uh, would be fresh water as well. And so there were all these stories of people, you know, from 1500s or whatever it might be, where people were running dangerously low on water. And they're, they're literally about to die of thirst, you know, that they're all about

• 9:12Speaker 01

  to just literally wither away. And then there's one particular story, uh, Martin Frobisher, uh, 1578 this is, and they were in desperation. They hauled a chunk of sea ice on board the ship, melted it. And then to their, to their absolute amazement, it was fresh. They just, I mean, they just couldn't believe it. Cause it's sort of logically doesn't make sense. If you take a load of salt water, why on earth, when you freeze it, would it end up? Removing the salt from it.

• 9:39Speaker 00

  I got a question. The vial of water that you have.

• 9:42Speaker 01

  Mm hmm.

• 9:42Speaker 00

  Was that originally collected as ice and then it was melted? Or was it collected as liquid water?

• 9:48Speaker 01

  You are too smart. Uh, okay. So this was actually collected from the bottom of uh, the ocean in the North Pole. So it says on it, it says that it was collected. Uh, here we go. Four thousand three hundred and two meters underneath the ice sheet.

• 10:05Speaker 00

  Wow.

• 10:05Speaker 01

  So this is your, you know, you're, you're extremely smart here because actually I think if you tasted this, it would end up being salty. But it turns out that this stratification, as it's known, essentially what happens, this unfrozen water absorbs all of the rejected salt. It becomes really, really salty, freezing cold liquid.

• 10:27Speaker 00

  Okay, so I, I thought this was liquid water collected, so I assumed it would be salty. But you're saying, I, I feel like frozen water, ice would not be salty because the salt would, would uh, lower the freezing point of the water. So, so it just wouldn't freeze.

• 10:46Speaker 01

  If you go past minus two degrees centigrade, it will freeze.

• 10:48Speaker 00

  Okay. How many vials do you have? Just that one?

• 10:52Speaker 01

  Just have the one.

• 10:53Speaker 00

  Hannah, you gotta get two so you can drink one and keep the other.

• 10:56Speaker 01

  What you really want is one from the top and one from the bottom, and then a little sip from each.

• 11:00Speaker 00

  You want one from every like 10 feet of depth so that you can have like a little, you'd pair one with a, with a steak and one with your ice cream.

• 11:08Speaker 01

  As you go along, as you go along. Can I tell you a little bit more about this, this, this freshwater? Like massive lake, and it's massive, by the way, that is hiding underneath the sheet ice in the North Pole. Because it turns out it's like responsible for almost all of the dynamics of our entire planet. Like it's wild and I had no idea that this thing existed.

• 11:29Speaker 00

  I didn't either, but you, you call it a freshwater lake, but really it's a giant parcel of water, surrounded by water.

• 11:35Speaker 01

  Right. It's, it's a lake sitting on top of an ocean, right? But, but the thing is, is that I, I'm not talking about a small amount of fresh water here, right? I am talking about gargantuan amounts, more than all of the Great Lakes. Because in the summer, when all of the snow, all of the glaciers melt from Siberia, from Greenland, from Canada, from, from Svalbard, all of them empty into this great big basin that appears at the North Pole. So if you looked at the ground, the sort of the, the, um, the terrain under the ocean, beneath the North Pole, it is this little bowl. It's like this, it is a perfectly shaped little bowl.

• 12:14Speaker 01

  And with the Coriolis effect of the earth spinning, it's sort of this spinning little, um, little blob. I mean, it's not little, this spinning gigantic blob of fresh water that is sitting on top of a very salty part underneath. The other thing about this, okay, so this, this freshwater blob that is sitting there under the ice sheet. The really amazing thing about it is that it is protecting the ice from melting. Because that warm water that is coming up from the Atlantic, there is easily enough energy in the warm waters of the Atlantic to melt the entire ice sheet of the North Pole, right? Gone like this.

• 12:56Speaker 01

  The only reason why it doesn't and hasn't is because this cold water blob is stopping it from getting there. Because, because the salt water, even though it's warm, sinks to the bottom beneath the much lighter, cold, fresh water. So it can't get to the ice sheet. It's like, it's like it's insulated. It's a good, perfect insulation.

• 13:16Speaker 00

  Right.

• 13:17Speaker 01

  So you're like, oh, great. Thank you very much. Thank you very much, blob of cold water. I, I really appreciate this for, for not getting rid of the ice sheet. The Arctic can survive all of the creatures that need that freshwater lake to just to live. And all of the creatures on top that sort of feed from it are, are extremely grateful as a result. However, here's the big problem. The big problem is that the ice sheet is still melting from the top. You know, the sun is still beating down on it.

• 13:44Speaker 00

  Yeah.

• 13:44Speaker 01

  Still more heat in the atmosphere than there was before, which means that this blob of water is getting bigger and bigger as time goes on. And the real fear is that there'll be a tipping point where the blob gets so big that it shuts off the flow coming up from the Atlantic. Where you've got this giant, like evacuating lake of fresh water that spreads out into the Atlantic, stops the, the warm water from coming up. At which point it's bye bye mild winters for Europe.

• 14:19Speaker 00

  Right. It becomes very cold, as it should be, based on latitude alone.

• 14:24Speaker 01

  Based on latitude alone.

• 14:26Speaker 00

  Oh, my gosh.

• 14:27Speaker 01

  Okay. Well, maybe this isn't that big of a deal, you know, like they can live with it in Moscow. They can live with it in Canada. No big deal. Except that every single bit of infrastructure in Britain is built, as we have learned this summer, right, is built for a very narrow range of temperatures. Really, Brits are happy between plus five and plus 25. That's it. That's all, that's all we're happy with, you know? If it gets over 25, we break down. If it gets under five degrees, we're, it's game over for us.

• 14:56Speaker 00

  Yeah, things will need to dramatically change infrastructure wise.

• 15:00Speaker 01

  And up until now, this big question of this, this blob of water that protects the ice sheet, but threatens the, the, the temperature of Europe, what is it gonna do? Is it gonna stay there? Is it gonna stabilize? Is it gonna grow? Is it gonna shrink? Which way is it gonna go? And uh, for a really long time, people were like, no, no, no, no. There, there was a group of people who were like, no, no, this is protecting the ice sheet. Actually, we're in a state of stability. This is not a problem. But in the last couple of years, things have started turning for the worse. And now the models are saying that it is genuinely possible that by 2070 or so, this conveyor belt of warm water from the Atlantic moving up towards the North Pole

• 15:44Speaker 01

  will start slowing down enough that it's really gonna be uh, bad, bad. In our lifetimes, basically, Michael.

• 15:51Speaker 00

  Has anyone named this freshwater lake blob?

• 15:56Speaker 01

  Yeah, the lake blob. Yes, they have. It is called Beaufort-Geyer.

• 16:01Speaker 00

  Oh, wow. Beaufort-Geyer is a fantastic name.

• 16:06Speaker 01

  I didn't even know it was there. I had no idea it was there.

• 16:09Speaker 00

  No, I just assumed it was regular ocean water everywhere, but apparently there's this structure of like floating sea ice. Then you've got this Beaufort-Geyer of fresh water. And then below that, you've got the salty, even probably maybe more salty than regular ocean water.

• 16:26Speaker 01

  Shall I, shall I open it to have a little sip?

• 16:29Speaker 00

  Well, yeah, of course. I wasn't gonna ask you to because it'd be awkward, but you, you should.

• 16:33Speaker 01

  This feels like that moment when you lick the rock, you know?

• 16:36Speaker 00

  I know. Like, there are risks here. I am, I, you're doing this under your own free will.

• 16:43Speaker 01

  It's salty. Oh, my God, that is the saltiest thing I've ever tasted.

• 16:47Speaker 00

  Okay, so it's, it's from what, 4,000 feet or meters? How deep?

• 16:51Speaker 01

  Meters.

• 16:52Speaker 00

  Wow. Okay. So you did it for the gram, you took the sip, and it was really salty. So saltier than regular seawater?

• 17:01Speaker 01

  I think that's saltier than regular seawater.

• 17:03Speaker 00

  Yeah, well, it makes sense.

• 17:04Speaker 01

  I don't make it a habit of drinking seawater from little vials, but, but in my experience, that is extremely salty.

• 17:13Speaker 00

  Wow. And aren't you glad that you've tried it now?

• 17:15Speaker 01

  Yes, I am. Maybe I'll, maybe I'll sprinkle a little bit on my dinner later and say, what do I think is so amazing to imagine though is that like this little bit of water that was literally at the bottom of the North Pole, for, you know, nearly four and a half kilometers at the bottom of the North Pole. Think of everything that swam above it, you know? Like, think of everything that it, that has been seen in that area, that we just have, it's so uncharted. We just, we just have so, so much to learn about, about our oceans and, you know, the Arctic in particular. It's like, it's wild to me. It's wild to me just what that could have seen. Or, you know what? I, I bet if I did some DNA analysis of, of all of the different creatures,

• 18:01Speaker 01

  who, who's, you know, floating little fragments of DNA have wafted through this. I bet there would be so much to learn from this little vial.

• 18:09Speaker 00

  There'd be so much DNA we didn't even recognize, species we have not seen yet.

• 18:15Speaker 01

  And now, and now I've assimilated it into my own body.

• 18:18Speaker 00

  You've consumed them. Yeah. You, you're one with the Arctic. Next step is to brine some chicken with that. I bet it would be too salty.

• 18:30Speaker 01

  Too salty. Listen, let's call it my narwhal smoothie, okay?

• 18:34Speaker 00

  Yeah, that's what it is.

• 18:36Speaker 01

  There you go. That was my, that was my little addition for this week. Hope you enjoyed. They're not always gonna be that good. I think that was a particularly good one.

• 18:43Speaker 00

  That's really cool. Yeah, it's not, it's not always gonna be the case that you've just come back from the Arctic, but you have these adventures and you just show up on the podcast and go, oh, look, I just got back from the moon. Um, sorry, my floor's a mess. And I'm like, ah, yeah, I know what that's like.

• 18:58Speaker 01

  You go to the moon of your mind, though, Michael. Also, I haven't been to the moon.

• 19:02Speaker 00

  Oh, that's right. The moon, the moon in my mind. And you know what? We're going to visit these uh, cognitive lunar landscapes after the break when we answer some questions from you all.

• 19:26Speaker 00

  This episode is brought to you by Cancer Research UK.

• 19:29Speaker 01

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• 19:40Speaker 00

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• 19:54Speaker 01

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• 20:06Speaker 00

  And AI trained on a database of over 10 million mammograms that helps doctors spot early signs of cancer.

• 20:13Speaker 01

  Research like this saves and improves lives.

• 20:16Speaker 00

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

• 20:29Speaker 03

  This episode is brought to you by Michelob Ultra. Good times mean competitions between you and your friends, like seeing who can throw some pigskin the farthest or rush the field the fastest. Winner gets an ultra. Because it's not just a superior light beer, it's also giving fans superior access to their favorite sporting events. Superior is worth playing for. Visit michelobultra.com/superioraccess to enter. Enjoy responsibly. Copyright 2026 Anheuser Busch InBev Michelob Ultra Beer, St. Louis, Missouri.

• 21:05Speaker 01

  All right, we're back. We have got your questions. The first one is from Reddit. We've been hanging out on the subreddit. We haven't posted it. Have you posted it, Michael?

• 21:16Speaker 00

  Well, no, I can't post. As I said before, I can't use my Reddit account. I can look at things, but I cannot upvote. I can't comment because I have to change my password. But I can only do that if I have access to my old at google.com email address. So I'm stuck. I'll need to just make a whole brand new account, but it's sad because I like my username, just Michael underscore Stevens. It's a good one. It's the one I've been using. Anyway, I have been lurking on our subreddit, not able to engage. And I loved this one. It starts, this is what it's called. It was written by Fosse. Fosse says, "I think this podcast spreads misinformation about science and the moon is flat. Just kidding. My real

• 21:59Speaker 00

  question is why are people more likely to correct someone online with a detailed explanation when they post something wrong, but are much less likely to give the same kind of thoughtful answer when someone genuinely asks a question?" I loved that because first of all, it proves how significant this phenomenon is. Like, I immediately click on this one because I'm like, oh, someone's being mean and wrong on the internet. Time for me to engage. And I come in and then I see that that's exactly what their question is about. This is a famous part of the internet. Like, the fastest way to get help online is to be wrong. If you want to know what kind of wrench to use on your 2022 Kia, don't ask, say, "Hey, here

• 22:41Speaker 00

  I am. I'm about to use a hammer to undo this fastener." And then everyone's going to go, "Don't do that!" And they'll tell you what to do. Why is that? And as it turns out, one, it hasn't been studied online nearly as much as I expected it to have been studied. But it falls within the purview of the psychological study of the difference between helping and fixing. Those are two very different behaviors that sometimes look the same when you're far away, but are very different things. And I think the first place to start is to recognize that when someone posts online, or even in real life, asks a question, that's

• 23:21Speaker 00

  a very open-ended challenge. You know, what's the best way to cook ribs? Well, there's a lot of different opinions. There's a lot to cover. There's the tools. There's the time. There's the temperature. There's what kind of ribs? What kind of cut? Is it spare ribs, St. Louis style? It's a lot. It's a lot of cognitive effort. But if someone shows that they're going to be microwaving ribs, boom, you've got one thing to pick on, which is don't do it that way. Or, I don't know, maybe you can microwave ribs. I don't know. But the point is, just on the surface, they are very different things. If someone's wrong, they're specifically wrong. But if they're just curious, they are open-endedly curious.

• 24:01Speaker 01

  I mean, that brings us back to that episode that we did about curiosity, right? Which is where people are most engaged when it feels like a missing tooth, where you know exactly the size and shape of the piece of information that needs to fit in it. And that's when you sort of get people's attention the most.

• 24:17Speaker 00

  That's right. So someone wrong on the internet is like a weird gap in your teeth that you just can't stop sticking your tongue through.

• 24:27Speaker 01

  That you need to be like, "I know what goes there. I know what goes there."

• 24:30Speaker 00

  You know what goes there. You know what to say. And the whole phenomenon, or rather, the whole feeling behind someone being wrong on the internet feels more urgent. Because, again, it's a specific thing and it can spread. Whereas someone not knowing something is not as urgent. Okay, someone will fill them in. Someone with more time than me, you can sort of do what's called social loafing, where because so many people are looking at this question, you'll let someone else answer it. But if someone's wrong, then that is a thing that has legs. It's more real and it can spread and others can get that information

• 25:10Speaker 00

  and they can do something wrong, break their microwave, ruin their dinner, hurt themselves. So you've got to act. But then at an even like more general level, fixing is easier because it's much more egotistical. It is about easing your own discomfort. Someone was wrong online and that makes you annoyed. And so to make yourself feel better, you come in and correct them. It's also like a judgment thing. You're judging the person's action and their theory. And that's fast for us to do. We evolved to make judgments very quickly. Good, bad, retreat, approach, those are fast things. But helping requires

• 25:55Speaker 00

  listening. It requires reasoning. It requires figuring out what the person already knows and what kind of knowledge base they have. And it requires sharing someone else's perspective. It isn't just about reducing how your discomfort. It's about sharing someone else's discomfort and working through it with them. So it's a lot harder in like three ways. Correcting someone, piece of cake. We do it instinctively. But helping someone in an open-ended way, that's a commitment.

• 26:25Speaker 01

  So you know, there is this trick. I possibly shouldn't admit to this here because then maybe I'll weaken the value of the trick in future. But sometimes when I make my TV documentaries, I get to interview scientists a lot of the time. And sometimes scientists who are so amazing in their own field, really struggle to understand what the best possible way to describe it to somebody outside of their field, essentially. I think it's just really difficult to find a word that capture the joy or the gloriousness of the thing that they're studying. And so sometimes you sort of have to help the scientist along, right? In describing their own stuff for what you know the audience needs. So anyway, if I'm with a scientist and they're being too technical, they're sort of, they're kind

• 27:09Speaker 01

  of in their own head a little bit. They're just being a bit too nervous, whatever it might be. The trick that I do, and it works, I would say, 98% of the time, is I will come up with an explanation and present it to them, something incredibly simple, something that I know the audience would like, but deliberately get one little detail wrong. And then what will happen is that the scientists will be like, "No, no, no, no. It's like this." And then they'll repeat my exact same explanation, but change the thing to be right. And then often add a little extra detail on the end. And like, nine times out of 10, that is the clip that will actually is going to come to the edit. But I don't necessarily

• 27:53Speaker 01

  know that that's what I'm doing. But honestly, it works so well.

• 27:56Speaker 00

  I bet it does. It's brilliant because you're giving them something much easier to hold, which is a specific incorrect thing, rather than an open-ended like, "So, what are you researching?" Oh, brother. They're going to immediately talk as though they were talking to a colleague. But if you say, "Oh, okay. So like, rocks have been here since the Big Bang?" They go, "No, no, no, no, no. Here's how rocks form." And you've given them a thing to push against.

• 28:25Speaker 01

  Exactly right. Yeah.

• 28:27Speaker 00

  You're reminding me also of that X KCD comic. So in the comic, these two scientists are talking to one another and the first one says, "Silicate chemistry is second nature to us geochemists. So it's easy to forget that the average person probably only knows the formulas for olivine and one or two feldspars." And then the other scientist goes, "Oh, well, and quartz, of course." And they go, "Oh, yes, of course." So that's how it is talking to experts often. They think that you have at worst like a graduate level, like entry to graduate program knowledge. And really, you're still thinking.

• 29:04Speaker 01

  Is quartz a rock or a mineral? Or like, what is it? Is that the thing that they put in watches? What are we talking about here? Right, totally agree. I also think that sometimes scientists, I do feel a bit bad for them. I think that they are playing in their heads to the audience of their peers. Everybody is nervous about how they come across, every single human on earth. And if they're not, then I don't trust them. And so, and so I think sometimes people are like, they want to say the thing that makes them sound smart because, because their audience will hear it. But actually, it's the audience at home who are more important to listen to.

• 29:41Speaker 00

  Well, yeah, and there's a really big difference between explaining to a general audience a field versus talking about the specific thing in the field you've spent 10 years working on, which is like just the way a certain granual size of quartz moves through a riverbed in the northern hemisphere. And so that's where your mind is. And it's hard for you to go back and say, okay, so water flows downhill. Like, let's, let's start here. And I think that, yeah, what you just described is a brilliant way to get them, to give them handles to hold on to back here so that they can, you know, take us the rest of the way.

• 30:19Speaker 01

  Isn't there something about how on naval inspections, they would always deliberately leave a rope? I'm sort of half remembering something. You would always deliberately leave a little bit of rope that was like unfurled and not right. And then, just because, because I think when people do inspections, they always want to pick up on something. So that you deliberately leave something really obvious that they pick up on that and then they don't, they don't sort of, they feel like they've done their job properly.

• 30:44Speaker 00

  Oh, yeah.

• 30:46Speaker 01

  Well, I think you can be quite snaky about using this against people.

• 30:49Speaker 00

  Yeah. No, this is, I feel like I've heard jokes like this before where, oh yeah, if you want to lie about something, your cover up should be, should include something embarrassing or also kind of illegal, but not as bad. Because then people think, well, why would you, you know, how would that not be true? You know? It, it, it took a lot for you to admit that and it harmed you to admit that. So it's more believable than if you just said, oh, I'm innocent here.

• 31:21Speaker 01

  Wish you'd told me that before I went into traitors, Michael. Um, okay. Shall we? That's going to only make sense for the British audience, but there we go. Okay, shall we go on to the next question?

• 31:32Speaker 00

  This segment is brought to you by Cancer Research UK. Now, in the laboratory, a lot of things can kill cancer. But as it turns out, killing cancer in the body is a much bigger challenge.

• 31:45Speaker 01

  Yeah, of course. And, and that is because cancer cells are our own cells that have gone wrong. You know, they're literally part of us, which is going to make killing them much more complicated.

• 31:55Speaker 00

  Exactly. And also, our bodies are these incredibly complex mazes. They're, they're labyrinths. And so for a drug to launch its attack, it has to navigate all of these twists and turns to reach just the right spot.

• 32:08Speaker 01

  So today, we are asking, could a bath time essential steer us in the right direction?

• 32:14Speaker 00

  Obviously, that's where we were going with this.

• 32:16Speaker 01

  Obviously, the lead up was there. Okay, the science behind this is absolutely amazing, though. Because if you think about chemotherapy, chemotherapy is extremely effective at killing cancer cells. But the reason why you get sometimes such, such serious side effects is because it can also kill your own cells, right? It's really difficult to distinguish between what's you and what's the cancer. So what you would like to do ideally is to target the chemotherapy right at the point where the tumor exists and bypass all the rest of your tissue. The question is, how do you do that? How do you navigate the, the complex maze of your body to get it there? So Cancer Research UK scientists, they have developed these tiny little drug-laden bubbles

• 33:00Speaker 01

  that can float through your body and then burst inside tumors. I can hear you thinking, why bubbles? And the reason, the reason is because they are part gas, part liquid, but at the same time, they're solid enough that you can manipulate them. So you can, you can sort of create them, move them around, wobble them as you like. The other thing about bubbles is that you can pack the inside of them with the drug that you need. You seal the chemotherapy inside those, those micro bubbles. And we're talking really tiny here, right? One to 10 micrometers in diameter, smaller than the width of the human hair, over 30 times smaller than a grain of table salt. Really, really, really minuscule doses of extremely potent drugs.

• 33:41Speaker 01

  But to get them to the right part of the body, you need some sort of guidance system. So you inject them in and then these micro bubbles will find their way to the cancer. Either because they are attached with loads of antibodies to them, so it sort of uses the same technique as your immune system does to hunt down an infection, but instead it's these bubbles that are hunting down a tumor, you know, at which point it has the chemotherapy inside. Or sometimes what you can do, right? You can, you can attach these tiny magnetic nanoparticles to the bubbles and then physically pull the bubbles through the body with a giant external magnet. How wild is that? And, I mean, insane.

• 34:25Speaker 00

  I want to be the drug driver with the magnet who's just like, Anne, I'm going to put that here, I'm going to put that there.

• 34:31Speaker 01

  So, so when you get them to the right part, when, when you as the drug driver get there, then all you do is you beam ultrasound waves at the tumor. So the bubbles end up vibrating so much that they burst. And then the drug gets released at exactly the site of the cancer cells. This is like hyper-targeted drug delivery, keeping your healthy cells safe so that you end up with less side effects. And by the way, we're at the stage now where this successfully treats some cancers in the lab and, and they're now preparing to, to launch this in clinical trials.

• 35:02Speaker 00

  It's very exciting, but there's one other big challenge. Okay, so you can drive these drugs where you want them. That doesn't mean they can get through the gates that have been erected. Because although these bubbles are tiny, I mean, a fraction of a, of a grain of salt, guess what? Some things in our body are protected against even things that small, like the brain. Okay, brain tumors are a huge challenge for drugs because our brains are surrounded by this, it's basically this tight locked cellular bodyguard chain. It's called the blood-brain barrier. And it stops a lot of drugs from getting in. Even if they're in a bubble, they're still too big. So to give you a sense of how tight this blood-brain barrier is, you can only fit something

• 35:46Speaker 00

  that is smaller than seven molecules of salt. Okay? Not, not a little like piece of a piece of a salt, no, seven molecules of sodium chloride. That's it.

• 35:59Speaker 01

  And how many are there in a, in a grain of salt? I mean, it's a lot more than seven molecules.

• 36:03Speaker 00

  A single grain of salt contains about a quintillion molecules. That's not a billion, that's a billion billion. And we can only get seven of them through. So what do you do? Well, Cancer Research UK scientists have a new idea, a solution here bubbling up in their minds and their work. So the drugs are often too big to get in. No problem, let's use bubbles, not to transport them in, but to open up that blood-brain barrier. So you take micro bubbles, just empty micro bubbles, send them up to that blood-brain barrier and then blast them with a beam of ultrasound, which is sound that's just too high for us to hear. And that causes the bubbles to wiggle around. It causes them to expand and contract.

• 36:47Speaker 00

  And that expansion and contraction can actually open up a larger opening in the blood-brain barrier for the chemotherapy drugs to get into the brain where they're needed. You know what it's like? It's like, it's like a heist movie, okay? But like too small to see. It's breaking into the, the.

• 37:04Speaker 01

  Making it through the wall.

• 37:05Speaker 00

  Yeah. But it's breaking into the vault. You're too big, not, not if you dance. Okay? Not if you have scientists with ultrasound exactly formulated to wiggle you.

• 37:16Speaker 01

  Stretching you and squeezing you exactly the right way.

• 37:19Speaker 00

  Cancer Research UK is launching clinical trials to test micro bubble delivery of chemotherapy to brain tumors in children and young people right now. And this could offer a, a vital treatment for young patients who lack options. And this gives children and young people more moments with their loved ones. So the point is, though, that by backing bold ideas from the laboratory to the clinic, Cancer Research UK is helping develop better, more tailored treatments.

• 37:46Speaker 01

  Right. And, and that means that they work for more people, for people with more types of cancer with, with fewer side effects, crucially. In fact, Cancer Research UK's work has played a role in more than half of the world's essential cancer drugs.

• 38:00Speaker 00

  That's right. Cancer research that's happening today will change the future of cancer medicine, including for hard to treat cancers. And by tackling the biggest challenges, more people can live longer, better lives.

• 38:13Speaker 01

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

• 38:22Speaker 00

  Trevor emailed us asking, how often do coincidences occur? What is the weirdest coincidence in history? How often do we mistake coincidence for fact? And are they always mathematically explainable?

• 38:36Speaker 01

  Trevor, that's like seven questions in one. And I like it a lot. I'm here, I'm here for the layering of questions. Okay, I've got, I've got what I think is. Is a really good submission for the weirdest coincidence. So a friend of mine, David Spiegelhoutser, who is a Cambridge mathematician, one of my colleagues, he did this whole entire project on coincidences where he got people to submit their coincidences. Because I think that when you, you know, if you talk to the mathematicians or statisticians, they will say that actually, there's a few simple laws behind this. One is the law of truly large numbers, that if you, if you try something enough times,

• 39:16Speaker 01

  even if it has a very small chance of coming true, that actually it becomes a statistical inevitability. So a different Cambridge mathematician, Littlewood, he was around about a hundred years ago, really amazing mathematician, Littlewood was, but he was like, okay, well, suppose a miracle event is, is, happens one in a million, it's a one in a million event, which sounds impossibly rare, but if you're awake for eight hours a day, like looking for, you're out and about for eight hours a day, and you experience, you know, one distinct event every second, Littlewood's life was apparently more interesting and exciting than the nine, but you'll rack up a million events every thirty-five days, you know, and even if you sort of halve that

• 39:59Speaker 01

  or quarter it, you're talking about one in a million events that will happen a couple of times a year, you know, and I think that in a lot of ways, that you, that is the way to think of things, is that you, you are essentially rolling the dice every moment of your life, you are allowing the possibility for coincidence to happen every moment of your life. All the same, some of them are incredible. So, so David Spiegelhoutser in this project asked loads of people to submit their, their greatest coincidences, and my favorite one, by a long stretch, is about Ron Beederman's trousers. He tells this much better than I do, by the way, but essentially, somebody wrote in with this coincidence and

• 40:41Speaker 01

  they verified it and fact-checked it, and it's absolutely true. There was a backpacker called Doug, he was the one who wrote in, and he was working in Miami when all of his possessions were stolen during this, this Greyhound bus trip, and he literally had nothing apart from what he was wearing. And so when he went back to his hostel, there was this New Yorker called Ron Beederman, he was very kind, took pity on him, had some spare clothes, and then gave him this pair, this, this shirt, sorry, this, this shirt that had like these very, these kind of very broad red dull stripes, this is Ron Beederman's shirt. Anyway, Doug, he eventually returned to the UK, he stores the shirt in this box in his attic, he doesn't

• 41:23Speaker 01

  think of it at all. Two years later, Doug is heading to London and he needed some temporary clothes to, to, to wear, so he gets this shirt out of his attic, he puts the shirt on, and he's, he's at this backpacker's hostel in Earl's Court, and he goes down for dinner and he starts talking to this girl who was sitting opposite him, and she says that she just got back from, from a hostel in Israel. And then Doug, who was making conversation, was like, oh, I knew this guy from New York who spent a lot of times in hostels and had been in Israel as well, and you know, I think he, like he'd been around that area. And she was like, oh my gosh, I know him, do you mean Ron Beederman? She was like, and he's like, yeah, I do, I do mean Ron Beederman. So they had this like strange connection.

• 42:05Speaker 01

  And the girl was really stunned. And then Doug says, oh, I, I, I always remembered Ron Beederman, because he gave me the shirt that I'm wearing right now. And then she is like, you are kidding me, because I, he gave me a pair of trousers that I am currently wearing, and she stands up and they are wearing the matching set, the matching shirt and trousers combo, that Ron Beederman gave both of them in completely different countries, one in Miami, one in Israel, they met in London. That's good, that one, that's good.

• 42:37Speaker 00

  I'm kind of not that amazed by it, Hannah. I guess maybe I'm thinking about it too much, and I'm like, these people are clearly backpacking around and staying at hostels all the time, they're running into a lot of people, and the kind of person who's going to lend you their shirt or give you their shirt is a very social person who's going to be remembered and give a lot of gifts around. Like, you're talking about two years later, there's a lot of, a lot of time for you to run into someone else who knows the same backpacker you did and was also a recipient of their largesse.

• 43:09Speaker 01

  Well, there's also, there's also how many backpackers are there in the world? How many opportunities are there in the world? There's sort of a survivorship bias to these stories, because the ones that are really extraordinary end up being the ones that are told over and over and over again.

• 43:23Speaker 00

  Oh, for sure. Yeah, here, here's a, here's a coincidence, just if you don't mind me telling you a little quick one.

• 43:28Speaker 01

  Hmm, please.

• 43:29Speaker 00

  Our neighbors, one of our neighbors, we hadn't really met for like a year, we just never saw them. And just like last week, my wife saw a woman outside the house and was like, oh, hey, how's it going? What's your name? And the neighbor said that her name was Marty. And my wife is like, oh, that's, that's so similar to my name. My wife's name is Marne, like the Hitchcock film, M-A-R-N-I-E, Marne. So Marne and Marty, turns out, they both have husbands named Michael. So we've got Marne and Michael, and Marty and Michael.

• 44:03Speaker 01

  That's amazing. That's amazing. That's one type of coincidence that you could have discovered with your neighbor, but maybe it could be that you both went outside and you were both wearing the same pair of shoes, or it could be that your, your daughters have the same name, or that your daughters were born on the same day, you know?

• 44:20Speaker 00

  Right, right.

• 44:21Speaker 01

  The number of different possibilities that you would accept as a strange, as a strange coincidence is gigantic, super gigantic. The thing I like to think about is of all of the times that I've met my, you know, my neighbor when I was in Kenya, right, and I saw them in Kenya and was like, wow, this is weird. For all of those times, I like to think about the, the much greater number of times that I must have just missed somebody, I'm just like a near miss coincidence.

• 44:50Speaker 00

  Yeah.

• 44:51Speaker 01

  And if you could only calculate those, those I think would really blow you away.

• 44:55Speaker 00

  Yeah, I've, I've had this idea for a while, ever since I saw Signs, you know, that, that, that like Alien movie?

• 45:02Speaker 01

  Hmm.

• 45:03Speaker 00

  But coincidences can be scary, and I think that movie must involve some coincidences or something, because I thought there should be a horror film where what's scary is that a bunch of coincidences start happening. No one gets hurt, it's just like, wait, why is everything working out? Why is everything related? What is going on? That, that could be really unsettling.

• 45:23Speaker 01

  Hmm, I need to watch it, I haven't seen it.

• 45:25Speaker 00

  I haven't seen it in so long, but I remember being inspired to do like a whole horror film about coincidences, because in Signs, coincidences are part of the story? Let us know in the comments, leave us a, leave us a lot of comments.

• 45:40Speaker 01

  Please do, tell us your coincidences, I would like to, I genuinely would like to do.

• 45:43Speaker 00

  I would love to hear those, yeah.

• 45:45Speaker 01

  Absolutely, yes, thank you, that would be great. All, all however many hundreds of thousands of you that watch this, please tell us your coincidences. There'll be coincidences between them, there'll be, you know what I mean? Like, if there was, anyway.

• 45:58Speaker 00

  So yeah, leave them in the comments below, and continue emailing us questions, we love these. And, and one of these days I will be able to interact with you on Reddit, so, so join us there at r/the rest is science.

• 46:10Speaker 01

  What I'm gonna do to all of the people who've written coincidences in the bottom of us, I'm just gonna go through and everyone and comment, yeah, law, law of large numbers, yeah, law of large, yeah, law of large numbers, over and over and over again.

• 46:21Speaker 00

  We will explain every single one of them. Well, Hannah will, I don't, I don't promise to.

• 46:25Speaker 01

  I'll see. If there's any that I can't explain, then we'll definitely include them. I'm, I'm happy to be proved wrong, I'm happy to be proved wrong, as ever. As always, please do send us in your questions, your coincidences, hey, why not, to the rest is science at gohangar.com, and we will see you next week.

• 46:39Speaker 00

  See you later.

• 46:56Speaker 04

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