Amy Barrett: So I'm here this morning with Matt Parker.


Matt Parker: Hello.

AB: Steve Mould.

Steve Mould: Hi.

AB: And Helen Arney.

Helen Arney: Hello.

AB: They are the three spoken nerds and they've recently launched an new podcast. Matt, can you tell me about the Podcast of Unnecessary Detail?

MP: I mean, it's all there in the title, to be entirely honest. All of us have a background both in something sufficiently sciencey – the other two are physicists, I tend to be far more mathematical – but we also have a background in comedy like stand-Up comedy and performing.

And I think what we realised is both of those, what they have in common is an obsession with detail and getting down to the finer nuances or just paying attention to the small, you know, the very close up resolution that a lot of people ignore. And that's what we ought to delight in, in the podcast, because too often you get told that the details are boring. They don't matter. You want kind of a broad brush approach to something. We're like no, sometimes things only get really interesting if you get very close and you get almost lost in the tiny details.

And so we figured if we just call it a podcast of unnecessary detail, it's all there in the title. And people can't complain that there was too much detail. Because that's what they've signed on for. So by setting the bar at unnecessary, we've kind of it's insurance against heckling, I guess, is the short way to put it. So we all will pick a word or a topic or something that we're interested or obsessed by. And we'll take turns looking at something in an undue level of detail.

AB: And so for your podcast episodes you've done words like rings, tables, stick and fuel and I'm very excited to be doing a word with you today. But, Steve, what would the three of you be doing right now if it weren't for the pandemic?

SM: We'd be doing live shows. Yeah. So we said we're all stand comedians. That's how we met. Actually, we met on their standard comedy circuit in the Edinburgh Fringe Festival and all that sort of stuff. And we were lamenting, you know, we've got these science backgrounds sort of complaining about, you know, you can't do this sciencey material, at Jongleurs or wherever. You know, at the comedy store.

HA: That is a dated reference.

MP: You know when we were last active on the comedy circuit.

SM: So that's the kind of names we were banding about back then. But so we decided to start our own comedy night that was all about science. And, you know, that way your audience comes to you. And we were very surprised to find that there was an audience for it.

So yeah, we ended up doing tour shows around the country and all that sort of stuff. But our main thing, our main thing now is these regular new material nights that we do every month. We used to back in the before times and that was it. Just a lovely way to explore these ideas. And we can go into a bit more detail on the podcast.

AB: So when we confirmed this podcast collaboration, the Science Focus team took to Twitter, because that's always a good idea, help to find suggestions for a word for us to go into unnecessary detail, today. We had suggestions of balls, vaccine and therapy and even unnecessary itself. But Helen. What word have we chosen to discuss?

HA: Well, to be honest, I was surprised that no one came out with Topicy McTopicface. That's what happens when you ask the Internet.

MP: Wordy McLexicon.

HA: But we went through all the words and we picked a word that has got something that each of us have been obsessed about at some point recently. And that word is ice.

AB: I'm not sure I can say I've had an obsession with ice. But Steve, what does that mean to you?

SM: Yeah, it's funny that you're the odd one out in this scenario, isn't it? This is this is a bit of unnecessary detail for when you've got an awkward silence around the coffee machine when you eventually get back to the office. It's about freeze drying.

This is an amazing process. You probably had a freeze dried coffee, you get freeze dried fruit as well. If you buy a fancy cereal, the fruit in there, maybe you've got freeze dried raspberry or something like that. And it's completely counterintuitive to the way you normally dry things like that. How you dry clothes, for example. What's your process for drying clothes?

More like this

AB: Hanging out them out?

SM: Hanging out? Yeah. Put it in the dryer. Basically expose it to heat. Right. And then the water evaporates. You end up with dry clothes with freeze drying is completely the opposite. You take a raspberry, for example. You put it in a box, you seal the box and you lower the temperature to minus 40 degrees centigrade, which in Fahrenheit, by the way, interesting fact, is minus 40 degrees. It's the only temperature that is the same in Fahrenheit and Centigrade. An extra bonus, interesting fact there for you.

MP: When you ask how would you normally dry clothes... My method is to forget about it in the washing machine. Yeah. Overnight it will eventually dry itself out, which is what you're describing is putting stuff in a box and forgetting about it is pretty much my approach to drying clothes, so.

SM: Well done. You're kind of freeze drying your clothes. So, you freeze the fruit. So you've got ice in there. Now it's because a raspberries, mostly water. Now it's mostly ice. And then crucially, you suck all the air out of the box, so you lower the pressure.

And ice does this weird thing at very low pressures. If you bring the temperature back up again to room temperature instead of melting, it turns directly into a gas. So it skips the liquid phase completely. The solid ice turns directly into a gas. It's called sublimation instead of melting or boiling or any of that stuff. Sublimation is the word.

And what that does is it leaves holes behind where the ice was. So the structure of the raspberry or the strawberry or whatever it is, remains. And, you know, it's like if you if you pick a bit of a fruit out of your fancy cereal compact up and down your hand, it's really light and fluffy because it's full of tiny pockets of air that's actually really useful for instant coffee.

So freeze dried coffee, it's really porous. So it's really instant. When you add the hot water, it gets into all those pores and it dissolves really, really quickly. There's actually two types of instant coffee. There's the horrible kind and the really horrible kind.

It doesn't matter for me. It's like drinking coffee in the morning, not that I do it anymore, but it's like it's just what's the quickest way to get caffeine molecules attached to the adenosine receptors in my brain. And frankly, I'm still asleep, so I can't even taste it. But yeah, so the the the horrible kind is the freeze dried stuff.

The really horrible kind is the spray dry stuff. And when you spray dry coffee, that's like the traditional way of drying something you do with heat. So you get this coffee, you spray into a hot box and all the water evaporates. The problem with doing it that way is with all that heat there. Some of those aromatic molecules will escape the coffee as well as those aromatic molecules that give coffee its flavour. So when you spray dry coffee, you're removing a lot of the flavour, whereas when you freeze dried coffee, you're only removing the water. Those flavour molecules remain in the coffee.

And you can tell if you if you go into a shop, the expensive coffee, if you look at the actual granules, that is like brown chips, whereas the sprayed dry stuff, these horrible dark clumps of powder, and they're also much cheaper. That's a you can tell the difference. So it's amazing innovation in terms of in terms of coffee and actually wasn't invented by coffeemakers.

It was invented like a lot of things in a military context in World War Two, it was used as a way to preserve blood serum. Actually, that's a reinvention. It was used even by the inkers in the 15th Century. They would they would hike their crops up a mountain. The pressure is lower up there. It's colder up there. And their crops would freeze dry. So the method has actually been around for ages. In fact, the you can freeze dry stuff even in your freezer. It's just it happens much more slowly, like it happens quickly. Higher temperatures, but slowly at low temperatures. So in your freezer, that's actually freeze dried chicken on the surface of your chicken breast.

HA: Wow. I actually fed my daughter freeze dried beefburgers. Earlier this week, I was doing science at tea time, I never knew it. Thank you, Steve.

SM: You know when there's like a best before date on frozen produce. That's not because it's going to go off and make you sick. Like bacteria and other pathogens aren't going to grow in the freezer. It's just that it becomes unpleasant after a while because of all the freeze drying that happens.

MP: I would say on behalf of the the hipster fancy coffee drinkers of the world.

SM: Are you in that group?

MP: I am. I'm on the fringe, but I'm definitely in. In fact, while we're recording, I'm drinking coffee that I use my hand grinder to grind up the roasted beans, single source etc. However, even though your a hipster, coffee drinkers would never go near freeze dried coffee if you told them it was hand carried up a mountain and left to freeze dry by some traditional tribe, that is the only way you'll sell freeze dried instant coffee to hipsters.

AB: Do you know, I'm quite disappointed because I was listening to your Rings episode earlier and you all sounded like you were eating doughnuts or bagels or something very enjoyable.

MP: Those were bagels.

AB: I was hoping that for ice we might at least have some ice cream delivered in time for our podcast.

SM: Some cocktails maybe.

HA: Hey, you're just gonna have to wait for my section.

AB: Oh, I'm gonna get a knock on the door and get some ice cream turn up?

HA: No, you're gonna watch me eating an ice cream on Microsoft teams.

SM: Other video conference software is available.

HA: So, Steve, one of our episodes of the podcast, talks about decaf coffee, which, as Matt will strongly argue, makes coffee so much worse. Yeah, we go into how decaffeination works and all the different ways that it does make coffee much worse. So if you took decaf coffee and then spray dried it instead of freeze dried it, would that make it the worst coffee in the universe?

SM: Yeah, I think that is the worst coffee. Yeah. I'll have to try that.

HA: We've reached a new low.

AB: But if we know it makes it taste so bad. Why do we do it? Is there not another method of preservation that we could be doing to make good coffee instant?

MP: If only coffee already came in a small bean shaped form that's convenient to store transport and then turn into a beverage. Wouldn't that be something?

SM: Yes, very instant.

MP: Ok, it does take me a good 20 minutes.

SM: But, here's an interesting fact, instant coffee only really took off in countries that didn't already have a strong coffee drinking tradition. So freeze dried coffee or instant coffee is not really a thing in America. It is in the UK because we never really had a strong coffee drinking tradition. We had a tea drinking tradition. So, you know, our coffee is bad, but America's tea is bad. And I would actually argue that America's tea is more bad than our coffee is bad.

HA: Wow. We do get a lot of people writing into us at the podcast and now you will enjoy this too, Amy, and tell us that we haven't put enough detail in. But I feel like what Steve has just mentioned is the kind of detail that is going to cause a lot more letters in your mailbag than normal.

AB: Yeah, I'm going to forward them all onto you, Steve, to answer.

SM: Thanks.

AB: Moving from coffee over to snow-fakes. Have I got that right?

MP: Snow-fakes, correct.

AB: So we're not talking about liberals or millennials and the insults that we get online. What are we talking about, Matt?

MP: Yeah, it's a shame that the words snowflake has now come with more baggage than it used to. So so I've been running a campaign for many, many years against inaccurate snowflakes. And we're recording this as we are coming out of summer, straight into autumn. And winter is not far away. And people get upset when they see the first Christmas decorations going up.

I get upset when I see the first snow-fake going up, which is some kind of decorative snowflake, which doesn't have six points because all snowflakes have six fold symmetry there. They're hexagonal or they got pointy bits, but they're always six-fold. Whereas if you go out in the world and you look at shopfronts or BBC Two got this wrong a couple years ago with their Christmas decorations magazines. I don't think Focus magazine has ever fallen afoul of this.

AB: I can't imagine we would do.

MP: In my experience, exactly. But you'll see eight pointed snowflakes everywhere. Just you cannot have an eight pointed snowflake. So I started the hashtag snow-fake. Other options are available. I'm not the first person to campaign about this faux-flake is available for those of you who prefer that. And I first came across this because I've been annoyed at it because from a maths point of view, six-fold symmetry is really nice, very neat, and not that hard to fold from a piece of paper.

SM: So six fold symmetry is when if you turn this thing through a sixth of a turn, it looks how it was before you turned it sort of thing.

MP: Yeah, exactly. So we defined something as being symmetric in mathematics, if you can do something to it and it looks the same. So you turn it one sixth of a, you know, a full circle. So pi on three and it'll look exactly the same. And or you can turn over a six different ways and it will achieve.

SM: Like if I turned a square through a quarter of its own it would look at where it was before.

MP: Exactly. And I only ever thought about this from a mathematical point of view. Several years ago we were doing one of our live nerd comedy shows and the science writer Philip Ball was on the bill and they were talking about the chemistry background to this. And I'd never really thought that much about the chemistry side.

SM: Typical.

MP: Apart from occasionally when I'm tweeting about inaccurate snowflakes, someone will be like, oh, but what about, and then name some obscure form of crystal structure that ice can take on in some weird context. And a tweet is never big enough for me to reply. Well, first of all, I don't know enough chemistry, but secondly, it's not big enough for me to reply with all the details for why that is ridiculous and why I'm not counting that. But in an attempt to kind of respond to that, you know, crystallise my thoughts. I did look into why form.

HA: Sorry. I just got that.

MP: Thank you.

SM: That's not a flag on the virtual meeting, that's a lag in Helen's brain.

MP: It's a lag on the quality of my joke structure.

HA: If you do hear any squeaks and it's not me. It might be me. But it's probably the baby.

MP: In Helen's defence. My joke structure has a lot of inclusions, so it's fine.

So everyone says, look, water, when it freezes, gives you a hexagonal structure because of the shape of a water molecule, which people can picture from like classic science diagrams. What they might remember from school looks like a little boomerang for little kind of little angled top half of a triangle, let's say.

And that's because what we would say mathematically, it's the tetrahedral angle, because the oxygen in the middle has four kind of pairs of electrons, two of which have a hydrogen along from the right, and the other two are just electrons on their own. And we can't see the other two. We only see the two with hydrogens. And by 'see' I'm talking about in diagrams or the structure of the molecule.

And so it forms the angles, you words in the centre of a tetrahedron because it's four equally spaced points, because the hydrogen behaves a bit differently to just the electrons by themselves in terms of how far away they are from the nucleus. It's actually slightly distorted. But the angle between the two hydrogens, it's not the tetrahedral – 109 and a half degrees – it's in water 104 and a half degrees.

And everyone says, okay, well, you got a bunch of those and they form a hexagon. But the internal angle of a hexagon is 120 degrees. Whereas the internal angle of a Pentagon is 108 degrees, which is much, much closer. And so actually water. If it's free to crystallise, however, it Fancy's will form pentagonal rings because there is much, much closer to the angle in a water molecule.

SM: So why does it happen?

MP: I know, and everyone's like, well, water always forms hexagons. And I'm like, no, it doesn't. If it's just forming rings in a liquid, they'll be pentagons. That's amazing. That's crazy. It's only because of the way it then stacks into a lattice.

And if you want to have something repeating and nice and neat, then it gets forced into a hexagonal structure. And so the hexagonal shape you see in a snowflake is not strictly because of the shape of the water molecule. Like we're always told, it's because of the arrangement of lots of water molecules. When they get packed into a regular lattice after others, that's incredible. But that arrangement changes depending on the pressure and the temperatures.

Like Steve was saying, if you cool ice down, you change the pressure. Weird things starts to happen to it. And several steps later. Instant coffee. Well, I was interested in is what other types of ice would give you different shaped snowflakes. And a lot of people would mention ice structure number seven and chemists have named the different possible ice structures. They're up to something like 18. I think it's ridiculous. And they're all different pressures.

And so ice structure seven, you can get a cubic kind of square base. I'd be very careful because not face-centred cubic, that gets you back to hexagons, unbelievably. But you can get this much more cubic structure. However, it requires pressures of about three giga particles, which is like for 30000 times atmospheric pressure. So if we ever have a winter with a really high pressure system. Actually conveniently humans, we can survive up to about 100. So there you go. We'll be dead.

AB: If there wasn't there that I thought that might be likely. I mean, 2020, the way it's going could be the year.

MP: Exactly. I feel like I'm jinxing it. Well, if we have a winter with temperatures below negative 150 degrees Celsius, we might see some square snowflakes. And everyone's like, well, this was the jerk who made it happen.

HA: But then there would be no one to tweet on the hashtag snow-fake. So would it really happen?

MP: Exactly. So it's not going to happen. All these weird structures everyone throws at me. Unless you're on this show at the bottom of the ocean on one of Jupiter's moons or your deep in the Earth's crust where diamonds are forming like we don't naturally get these weird. I structures where you'd get snow forming. And so that's why I campaign against snow fakes.

Please join in if you see them. Tweet with the hashtag snow-fake. I always look forward to the first one of the season. It was interesting is because it's so much easier to fold paper with powers of two. So you get a lot of square two to two squared four. You get like a fourfold symmetry snowflakes that kids make and you get eight because this year it's actually super easy to fold six fold symmetry. Like to get that triangle in a bit of paper. Not that difficult.

I've got a YouTube video that goes into it is pretty straightforward, however, because kids always make eight fold ones. And because parents will often make typos, you will see a bunch of parents accidentally using the hashtag snow fake, intending to compliment what their kids are doing. It just comes off really passive aggressive. Amazing thing. My kid made hashtag snow fake. Those accidental snow fake tweets are my favourite, but my second favourite is everyone documenting the ones out there. So name and shame people who get snowflakes wrong.

SM: Especially the kids. Those idiots.

MP: I know. How are they going to learn?

AB: So if chemists have named the differing types of ice, which ice do I have coming from my freezer. What's the name of it?

MP: So they've numbered the different types of ice, which I think is superior former naming. So I'm onboard with that. So you'll have ice one almost all ice. You come across as ice one, which is the classic kind of hexagonal arrangement. If there's another flavour of ice, one which probably tastes exactly the same, which is under certain pressures and or temperatures, because with you get these things called phase diagrams, which will show you which combination of pressure and temperature will give you different types of ice. You can get the other one.

So our classic ice is ice one H. But if you're not careful, it can turn into ice one C, but atmospheric, normal conditions will not give you ice one C except a very, very high altitudes. And so only in extreme situations it won't survive to the ground. Any ice you see, and you're not dead, is ice one H. And you're not a chemist in an ice lab.

SM: If you've got two snowflakes in front of you, one is one H. And the other is one C. Can you tell the difference just by looking?

MP: Well one C you probably won't get hexagonal symmetry. I'm now really nervous they pronounce it I C, and I H because they use Roman characters. Chemists write in to BBC Focus with any complaints.

AB: And I'll forward them to Matt.

MP: So my mathematical guess is yes. But if I've learnt anything about chemistry, it's a mess. So there's probably a bunch of other real world complications which always ruin the wonderful mathematics. So I'm going to have to cope with I don't know.

AB: So if that's six fold symmetry. What else has got six fold symmetry that I can see?

MP: Oh, OK. So six hole symmetry is great in a lot of things, we want to pack things together well. So that's why bees there honeycomb is a hexagonal cross-section. There's actually something called the honeycomb conjecture that hexagons are the best possible shape if you want to pack them together really well, but minimise the amount of edges you need for the space inside. But that wasn't proven to definitely be the best mathematical arrangement until 1999. So was only a couple of decades ago. And humans, we've been working on it for centuries. It's only cracked very recently.

So actually all these things involving arranging things in a nice compact, potentially regular way. We've been considering it for a long time. So actually, the whole snowflake thing, why it's a hexagon goes back to Kevlar in who wrote a thing about why snowflakes are hexagons in 1611, but only very recently have we kind of got a proper understanding of why it forms in that particular arrangement. So it's been a question for humans for a long time, but only recently have we thought to crack the maths and the chemistry behind it.

HA: Matt, is this only because bees haven't been able to write scientific papers?

MP: I maintain the honeycomb conjecture is the record that the Earth record for longest time between discovery and proof mathematical result. Because bees cracked at what? Millions of years ago. How all the bees. I don't know. That's biology. Maybe even worse than that. That I have a chemistry. But then it took millions of years before a different organism proved that bees had it right all along.

SM: The star of David, just another example, starting with six fold symmetry.

MP: Thanks for joining in, Steve.

SM: Good to be here.

HA: Can I ask, is there any way that an eightfold snowflake could possibly exist in nature?

So the reason I'm asking is because so when we were on lockdown and I was on maternity leave, I bought a lot of fabric. And you are very lucky that the topic of this show is not fabric, but one of them, because I was it was because it was 3:00 a.m. and I have no idea what I was doing.

And I genuinely ordered some fabric off eBay in my sleep because I didn't realise I'd pressed by a great, great bulk purchase. This is true. Congratulations to any new parents who have also managed to buy things off the Internet without realising. OK. And it arrived and I thought it was snowflake fabric and it has eight points and I now cannot use it unless you can tell me that there is some kind of a pointed ice formation out there.

MP: Well, you got two options. So you could argue in some extreme pressures and temperatures you'd get eight, because even with our regular six, you sometimes even with a regular six, you sometimes get 12 because two snowflakes love each other very much and sometimes you can get three. And that's just if things form when the snowflake is originally crystallising.

So to get eight, I suspect what you would need is either you might get it organically. If there's something which crystallises with a very regular cubic kind of square based structure that might give you four, potentially eight, or if you only get four one flake at a time. Two of them could merge and that would give you eight, but that they're pretty extreme situations.

The normal way to talk out of it is to say it's not a piece of fabric with snowflakes on it. They're actually stars. And when you get that kind of whatever the starring effect from a point source coming through the atmosphere like a like a flare thing that makes it look pointy. I'm prepared to accept you get a pointed traditional star studded if you can. You can do it. Do a switch to say it. Star fabric.

HA: I don't think my daughter is going to buy an Elsa costume with stars on, but I'm gonna try it. No.

AB: Or you could just embroider the hashtag snow-fake somewhere.

MP: That would fix it.

SM: That's a great idea.

HA: Christmas is saved.

SM: Daffodils.

MP: Do they also have six-fold symmetry, Steve?

SM: They do.

MP: Well done.

HA: I thought my brain was working slowly. And Steve is like, hmmm.

AB: So bees are not the only animal we're going to be talking about today, have got that right Helen?

HA: Oh, yes. So my take on ice comes from the song that I have put at the end of this podcast. So in a podcast of unnecessary detail we often finish with one of my scientifically accurate songs and this song that I'm kind of donating to the Science Focus podcast is one about an obsession I had a while ago with chronic freezing.

I guess you couldn't call it a science topic, particularly because it's more of a philosophical topic. And the reason I wrote this song about chronic freezing is because I met a professor at Oxford Literary Festival when we were doing a show together. He was a professor of philosophy, though, right. And he had a tag round his neck saying the usual thing. If you're a chorionic sign up, it says, you know, if I am dead, please call this number. And they come and they freeze his body.

And I'm like, this is amazing that I finally met someone who has taken the philosophical bet on whether science is going to be completely different in the future and will be able to revive a body filled with antifreeze. So I've got this song about chronic freezing and you're going to hear at the end and you'll find out all about that. But there's loads of details that never made it into the song. And that is all of the creatures and living things that already contain antifreeze.

MP: Oh, so you can freeze other creatures.

HA: Yeah. So this song was about chorionic freezing where, you know, your body gets filled with antifreeze and they get stored for a future time, that at some point someone might be able to revive you. And if you're a philosopher and you ignore all the science, that's quite a good bet, right? You pay some money every month into your kind of, you know, insurance policy that in the future you'll be revived. To a philosopher, that seems like a pretty good bet. Right.

But on the other hand, there are already animals and creatures and plants that have antifreeze inside them, which is what helps them survive in cold temperatures. And I've got three that I wanted to talk about because. I've got three that I want to talk about, and they're ones that I couldn't manage to get into the song somehow. And I found out all about them at the time. And and I've always wanted to be able to talk about them.

The first one is a grass. There are types of grass that are frost resistant because you can't move grass in the winter. And if it goes below freezing temperature, then it needs to survive it. I've only found this out because I was reading about some scientists who were trying to extract the antifreeze from inside the wheat grass. And they they basically spent the day mowing the lawn outside their research facility in order to harvest enough of this stuff. And it's it's an antifreeze protein that's produced by the grass that inhibits the crystal growth.

So the thing that causes the damage inside animal or plant cells is that when the water freezes into ice, it expands. And it's it's one of the only compounds it actually does. Is that right, Steve? It's not very common.

SM: I don't know if it's the only one. Is anyone I know of. It's certainly very, very rare anyway.

HA: And this is why your raspberry's when you freeze dry them. Right. The the water in the cells expands into ice. But then when your freeze dried raspberries get freeze dried, the structure is still there. But as soon as you add water again, they they just turn into mush, don't they? Yeah, because this ice has broken down the cell and it can't survive that process.

But wheat grass is able to produce antifreeze so that it doesn't die on a cold day. So that's number one. It might be outside your house or your office if you're in an office seems unlikely, but there's another one, Canadian tree frogs.

Now, when I found out about this, this is amazing. When Canadian tree frogs in the winter reach temperatures of minus 10 or minus 15 degrees out in the wild, their skin freezes. If you drop a Canadian wood frog in the winter, it clunks. It doesn't bounce. It clunks because it has an antifreeze that it produces inside its bloodstream.

So the antifreeze proteins cause the blood to freeze. This is different from the grass stuff where the antifreeze proteins, they're they they stop the ice crystals forming. Right. This is different. It actually encourages the blood to freeze. So it actually sucks the water out of the cells. And then the frog's liver produces all of this sugar and glucose, which then packs into the cells. So the result is a frog where the blood is frozen, but the cells are full of sugar and dehydrated. And that's how it survives.

MP: So you can freeze... Like frogs can be freeze dried, and then, when it thaws out, it's alive. And if I know well, if anything like coffee, it's also going to taste terrible.

HA: But it would taste better than if it was spray dried.

MP: Good point. Good point.

HA: That's how it survives. It kind of uses its blood to try to make sure that the blood gets frozen. And that sucks the water out of the cells or the cells don't burst because they're not full of ice. They're full of sugar rather than water ice. So they have this weird system and it's kind of the opposite of a way. But wheatgrass does it because that stops the cells. For me, it's all the fruit kind of redirects where the frozen ice happens in its body. So it manages to survive.

MP: I want to take back my previous statement, because if the cells are now full of sugars, it might taste better. So.

HA: It could taste delicious. That is not encourage anyone to try that.

MP: If anyone knows what a Canadian frozen tree frog tastes like, write in to BBC Science Focus.

HA: I'm going to get so many e-mails.

So there's a third one, which is probably the one that people have heard about before, which is the Antarctic fish. So in 1969, Arthur DeVries found it when he was researching Arctic fish, that they produce antifreeze in their bodies that can help them survive up to minus two degrees Celsius. So these are I've had a go at pronouncing his word and people can tell me if I've got this right, nototheniodies.

They are a type of Antarctic fish like, I think the pout fish is one of them and they produce antifreeze glycoprotein, which stop them freezing in the subzero Antarctic waters. And the reason you might have heard about this is because that antifreeze glycoprotein was extracted and reproduced and used in ice cream. Yeah, I told you I thought it was gonna happen at some point. Not in the way you think.

I've had a look. I actually went round Tesco this morning and I looked at every single packet of ice cream and none of them have this ice structuring protein. That is the the name for this thing. So it's fish, antifreeze. And the the way they get enough of it to put into ice cream is not by, like, milking a fish. They don't just, like, squeeze a fish until it comes out. They've found the part of the genetic code that creates the antifreeze. And they've done the same thing that they do with insulin and food flavourings as they've inserted into yeast. And then the yeast has gone and multiplied loads and loads and loads and also produces antifreeze.

And then they go ahead and harvest the antifreeze from the genetically modified yeast. It's in ice cream in. At various points in time, it has been in ice cream in the USA and I think Australia and Presenta places that you can't find in European ice cream. And I don't know why I've checked regulations. Why?

MP: I do remember in Australia, fish ice cream.

AB: Why would you want antifreeze in ice cream? How how does it help?

HA: It seems completely counterintuitive, but it is the thing that the wheatgrass anti freeze does, which is it makes smaller ice crystals. And the thing with ice cream is it's a combination of like milk, proteins and fats. And all of that stuff is a nice structure. And inside that, you get ice crystals and air pockets and those ice crystals and air pockets. It's that combination of those and the size and the structure that makes ice cream taste good. And weirdly, smaller ice crystals means better tasting ice cream.

The smaller the ice crystals and the smaller the air pockets. And also ice cream starts to degrade as soon as it leaves the factory. So as it comes out the factory, it's this lovely combination of tiny ice crystals, tiny air pockets and all of that lovely fatty sugary stuff around it. But as it goes through time, the air pockets start to bleed together.

The ice crystals get bigger, quite a lot like Steve and his freezer burn thing with ice crystals get bigger as you leave stuff in the freezer for too long. And that means that the ice cream that uses this antifreeze in it never gets those big ice crystals. The ice crystals in the first place are much smaller, which means it tastes much more creamy.

MP: You know what goes well with a fish ice cream?

HA: No.

SM: Chips ice cream?

MP: Frozen sugar frogs.

AB: And instant coffee.

MP: That's disgusting.

HA: These different ice structuring proteins, and they can be used to do exactly what you were talking about with your different types of ice structure. This is what can make snow-fakes real.

MP: That's amazing.

HA: I looked at I couldn't find one that made eight points. But you can force the ice to form in diamond shapes in like long needle shapes in spheres. So this ice structure in Britain will encourage different shaped ice structures as well as different sizes of I started depending on which one you use.

And I started looking into what other applications there are. And when I first researched all of this stuff to write the song about cryonics, there were loads of future applications that could possibly be part of the future of antifreeze glycoprotein. And I've got to say that a few years on, I looked again. And almost none of them have happened. It's really sad. It's truly sad.

So there is one product that has been marked. There is one product that has been created and marketed successfully. I looked at their website this morning. It is called Snow Max. Right. And the opposite of pretty much all the other applications. It doesn't inhibit freezing. It actually helps freezing. Snow Max is a product that makes better quality fake snow. So it's not the antifreeze protein that is used in ice cream or wheat grass and that it comes from a bacteria called Pseudomonas Siringae. Someone can correct my pronunciation on that one. And it is a snow inducer.

So rather than stopping ice crystal forming, it actually helps ice crystal forms like the like the proteins in the tree frog blood. It actually nucleate snow. It nuclease ice. So it actually makes snow happen and it makes better snow. It freezes faster at a higher temperature and it lasts longer. Which means your fake snow machine will use less energy and you'll get better snow. So this is a product that genuinely has been taken from nature and turned into something that is affecting all our lives. If we are people who visit the Alpine resorts where they add fake snow, I don't know. This could be the future. It almost certainly will be the creature if you count climate change.

SM: Is this the bacteria that spend some of its life in clouds?

HA: Yes, it is the same bacteria as that cloud stuff. But this is how it works. It's the proteins that that bacteria creates that are the nucleation of the snow. So you can now get them in in a bag, at vast expense and help you make snow.

HA: But do I have to be careful of, you know, going somewhere that has fake snow, that I don't get any on my tongue like you seen others of people running around with a of hype and catch it.

HA: By the time it gets into the snow making additive packet it's not active anymore. It's I don't know. Maybe they freeze dry it, Steve. I've no idea what they do it.

MP: Their website claims they freeze dry it.

SM: Does it really?

MP: Yeah.

HA: There you go. So if it also tastes as good as a tree frog at the same time. There's one final thing I want to mention, which is that there is still potentially one use for these antifreeze proteins that is still being worked on. But potentially could be amazing. And that is with organ preservation.

So with a donated organ, you have to get it to the recipient within a few hours and keep it around zero degrees centigrade. Otherwise, it starts to break down. But there's a possibility that these antifreeze proteins could be used to not only extend the life of the present, extend the life of donated organs, but also be used for storing tissue, because the moment if you're storing like frozen tissue for a few future use.

Not like an a whole organ, but just some tissue you need to use, like ethylene glycol, which is a kind of antifreeze, glycerol. You need to stuff it full of stuff that isn't brilliant and is quite toxic. And potentially antifreeze proteins could be used because they're less toxic. They have lower concentrations to get the same effect. So that's a potentially. Can you see where I'm coming back to now? Cryogenic freezing may be possible.

SM: Wow. We got there.

HA: I mean. Yeah. So this is where if in the future at some point, if you choose current, if you choose cryonic freezing as your future, I don't necessarily recommend it. You may be stuffed with fish proteins instead of antifreeze. It's a possibility. And that's something I didn't know about when I wrote this song. So enjoy the song as a time capsule of where cryonic freezing was a few years ago.

Let us know what you think of the episode with a review or a comment wherever you listen to your podcasts.

This podcast was supported by, helping people build quantitative skills in maths, science, and computer science with fun and challenging interactive explorations.

Listen to more episodes of the Science Focus Podcast:



Amy ArthurEditorial Assistant, BBC Science Focus

Amy is the Editorial Assistant at BBC Science Focus. Her BA degree specialised in science publishing and she has been working as a journalist since graduating in 2018. In 2020, Amy was named Editorial Assistant of the Year by the British Society of Magazine Editors. She looks after all things books, culture and media. Her interests range from natural history and wildlife, to women in STEM and accessibility tech.