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Hannah Fry
Welcome to the Rest Is Science. I'm Hannah Fry.
Michael Stevens
And I'm Michael Stevens.
Hannah Fry
I think we should probably tell the listeners, viewers the origin of today's Field Notes episode because I am currently on holiday in Greece and as we were discussing what I could possibly do that was holiday related, our producer suggested that we just grab something on the way and we do an episode on sick bags. And at which point, Michael Stevens, would you like to, Would you like to tell the audience what you told us?
Michael Stevens
Well, yeah, I said, hey, I collect sick bags, barf bags from airplanes because they change periodically and it's a history. Someone needs to be documenting this and some of them are quite cute. So my collection, some of it happens to be here. So do you, do you collect them too?
Hannah Fry
Only the very plain white one that I picked off a BA flight on the way here. I can't say. I can't say. By the way, this makes you a baggist. Do you know this? There's an entire community of you guys. Well, yeah, I'm now joining you as a baggage with my. I mean, it's quite a pathetic entry being entirely plain white.
Michael Stevens
Well, I don't have a British Airways bag in my collection. Maybe when I come out to London, could you give me that one deal?
Hannah Fry
How many do you have in your collection, Michael?
Michael Stevens
Honestly, I only probably have a couple dozen. If you. It's. It's not very impressive. There are people who are doing a much better job than me.
Hannah Fry
There are. In fact, there's a great rivalry at the, at the very heart of the baggers community, there is the airsicknessbags.com bag museum, which the owner of which says, I collect bath bags. My collection currently contains 3,659 bags. Most are from airlines. While this website and hobby is an enormous waste of time, I like to think that it's a higher quality waste of time than many other places on the web. And what better description of our own podcast? Michael, This episode is brought to you by Cancer Research uk.
Michael Stevens
Here's something strange. Your DNA contains more ancient viral fragments than genes. The genes that build our cells make up only 2% of our DNA. And for years, that is what scientists focused on. They treated the rest, the ancient viruses and stu stuff, as junk.
Hannah Fry
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Michael Stevens
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Hannah Fry
For more information about Cancer Research UK, their research breakthroughs, and how you can support them, visit cancerresearchuk.org thereestiscience I sold
Michael Stevens
my car in Carvana last night.
Hannah Fry
Well, that's cool.
Michael Stevens
No, you don't understand. It went perfectly. Real offer down to the penny. They're picking it up tomorrow. Nothing went wrong. So what's the problem? That is the problem. Nothing in my life goes as smoothly. I'm waiting for the catch.
Hannah Fry
Maybe there's no catch.
Michael Stevens
That's exactly what a catch would want me to think. Wow. You need to relax. I need to knock on wood. Do we have. What is this table wood? I think it's laminate. Okay. Yeah, that's good.
Hannah Fry
That's close enough.
Michael Stevens
Car selling without a catch. Sell your car today on carvana. Pick up fees may apply. No one goes to Hank's for spreadsheets. They go for a darn good pizza. Lately, though, the shop's been quiet. So Hank decides to bring back the $1 slice. He asks co pil in Microsoft excel to look at his sales and costs and help him see if he can afford it. Copilot shows Hank where the money's going and which little extras make the dollar slice work. Now Hanks has a line out the door. Hank makes the pizza. Co pilot handles the spreadsheets. Learn more@m365copilot.com. And I'm really glad that there's someone out there with thousands of barf bags they've collected and probably like meticulously written down, you know, when they got it and on what flight. I think that's important. But for me, it's a conversation starter. You know, when I meet people, I never know what it is they're going to be interested in. I can show them physics, toys and puzzles, but sometimes they're like, I got books I can show them. Sometimes it's barf bags. And they find that really amusing, especially kids. So it's just good to have something that will capture someone. Really hook them always there.
Hannah Fry
Make people like you. Let's do it. Okay, so that is what we have coming up in this episode. I'm actually also going to just sprinkle in a little bit of the science of barf bags, why we need them, where they come from, et cetera. Because actually, it turns out there's loads of fascinating stuff to discover. I absolutely love that you collect bath bags. That just makes me so happy.
Michael Stevens
It makes me really happy too.
Hannah Fry
Maybe that's how we should start there. Michael, can you show us some of your absolute gems? What are your best ones?
Michael Stevens
Oh, yeah, let me go get them. That's quite a big box labeled with a little sticker of myself covered in Vsauce. It's kind of like barf bag esque. It helps me remember.
Hannah Fry
It is quite barf bag esque.
Michael Stevens
Well, I also collected these. These are little envelopes of, I guess, hygienic materials during the pandemic. So there's a mask and alcohol wipes in here. This is from Air New Zealand, I believe. I'm just guessing based on the typeface, it doesn't actually say. Now I'm going to save their barf bag for the end because it's really impressive. Hold on, I'll show you. Okay, we've got like, here's one from Delta. And this is. It actually labels itself for baby care and feeling better. You can puke in here, but you can also put diapers in, which is how I tended to use them when we were flying with my daughter when she was diapered.
Hannah Fry
Can I rate these as you go? I think that's clean, functional, not that interesting. I would say that that is if. Let's. Let's normalize this. My completely plain white one from British Airways is a. Let's give it a one star. I think yours, the Delta one is a one and a half.
Michael Stevens
So wait, BA actually just gives you a blank bag, no instructions?
Hannah Fry
Sorry, what do you mean instructions? Vomit in here.
Michael Stevens
Even like some jokes or like there's a lot of here. For example, this one's from Eurowings. And if you look, it's got a little. A little some German on there.
Hannah Fry
Lieber ein popcorn tutor gewerten.
Michael Stevens
Yeah, they have an English translation on the other side. It says I wish I was a popcorn bag. Sorry, you're a barf bag. So see, Eurowings knows that you may as well give someone people some entertainment that is entertaining.
Hannah Fry
I like that one.
Michael Stevens
This is from Air Portugal. And this one has Portuguese on it. They've English in here. Hope you won't need this bag.
Hannah Fry
It's wishing well. So far Eurowings is winning.
Michael Stevens
This one tells you what you can use the bag for a little bin so you can help keep this airplane clean. A piece of paper to doodle on wrapping paper should you have forgotten to wrap presents for your loved ones or a sick bag when you're not feeling 100%. So yeah, they're very versatile things, Michael.
Hannah Fry
If you ever get me a present wrapped in that sick bag. I will. I will not be pleased.
Michael Stevens
Yeah, right. Can you imagine if someone gave you a barf bag wrapped gift? So here's, here's one from Virgin Atlantic, which is really standard, right. And I wanted to use this to compare it to what Air New Zealand gives people today.
Hannah Fry
I'm disappointed in Virgin. Hang on a second. Right, okay. This Air New Zealand, right? Let's tell you first. The Virgin Atlantic one is. It's entirely white apart from the logo. Virgin Atlantic, which is across the bottom, it's barely a up from the BA one.
Michael Stevens
Right.
Hannah Fry
It's. It's just, it's not, not interesting at all.
Michael Stevens
Its size, by the way, I can tell you that it is. It's about 11 centimeters by maybe 23. Okay, so it's like a pamphlet. It's like the size of a brochure, I reckon.
Hannah Fry
Similar to the BA one.
Michael Stevens
Exactly. There's like a standard size to these and they just change the, the logo that's printed on them. But Air New Zealand has started giving people these behemoths and it's like twice the size. This has room for you and your friend to barf in and I love that.
Hannah Fry
I'm not sure that's reassuring. I'm not sure that increasing the volume of expected barf is a good sign that the airline knows what they're doing. Okay. I think, I think you want to be on an airline that minimizes expected bath.
Michael Stevens
Gosh, I don't know which airline this is from. I'm not. I have not done a good job of marking down when and where I got them. But this one is also bigger. The commenters will have to tell me what airline that's from. I can line them up and you can see that the Air New Zealand bag, the purple one, the lavender Air New Zealand bag is a little bit bigger.
Hannah Fry
It's giant.
Michael Stevens
Yeah. This one's pretty big, though. Here's Virgin Atlantic compared.
Hannah Fry
Pathetically small.
Michael Stevens
Yeah. And the, and the big Air New Zealand one says Easy queasy on it. So it's a little. Got a little bit of cuteness.
Hannah Fry
Have you ever actually used one of these? I mean, okay, obviously not the ones in your collection. I would like to think you had better hygiene standards than that, but have you ever actually needed to vomit on a plane?
Michael Stevens
No, I've never. I don't get motion sick anywhere. Not on boats, not in cars. I've used barf bags to hold diapers. Not, not my own, but my daughter's diapers. When we had to change her on a plane. So they're. They, they're very useful. What about you, though?
Hannah Fry
A couple of times I think I do get a bit of motion sickness, but usually if I'm looking at my phone or sitting backwards or I sort of have. I've worked out over time the ways to avoid it, which is that you just need to have a connection to the outside. I mean, you're much less likely to get motion sickness if you are. Yeah. Looking out a window. Or there's the new accessibility option that comes on phones where they have the dots that move around according to what the accelerometer is doing. It's just so that your brain has this anchor that says this is how your body should be moving.
Michael Stevens
Yeah. Without an anchor, your brain is like, okay, I'm detecting motion. It could be, but I'm not detecting visually that we're moving. So this feeling in the ears of motion might be caused by poison or something we ate that was bad. So let's get it out, let's puke,
Hannah Fry
Hit the eject button. Thing is okay if you flew on some of the first aircraft, Right. If you flew in the 1920s or the 1930s, I reckon even you with your stern stomach, your resilience to motion sickness, I think you still would have had trouble because the early planes, they flew at these really low altitudes. They didn't have pressurized air cabins. And so it was like bouncing through a continual storm cloud while inhaling fumes of gasoline. I think it was really awful. And so they did used to have buckets which weren't particularly good. They would spill all over the place, like, or pots or then they also had like, sort of cardboard boxes that were lined with, like gum. It just didn't work very well at all. But this, the sick bags as we know it, they weren't invented 1949, really.
Michael Stevens
Post World War II.
Hannah Fry
Post World War II, exactly. One of the other great things to have come out of that era of
Michael Stevens
time, shall we say World War II and barf bags. That's all you really need to know about the 40s.
Hannah Fry
But what I will say is actually the need for bath bags on aircraft has gigantically reduced over time. And the main reason for this is because of the air cabin. Because once they worked out that you could pressurize the air cabin, that you could basically create this sort of vacuum seal around the outside and then inflate it like a tin can, then. Well, two things happened. First of all, your body is just at a, at a point where it can, you know, use more oxygen. It's not sort of. It's. It's not like you're, you know, sitting on top of the highest possible mountain peak anymore. You're. It's as though your body is like sitting at a lower level of altitude than you're actually physically at and just feels a lot more stable. Sort of like you've lowered the threshold for. For what you can experience before you start vomiting. But also because they pressurized them, it meant that they could go up so much higher. So they're not like in all of the turbulence that they were before.
Michael Stevens
Right, Yeah. I was gonna say I haven't seen anyone actually puke in a barf bag ever on all the flights I've taken. But they still offer them because they are so good for other things. Like I've said diapers, gum, you know, you've got, like, chewing gum. It's like, embarrassing. You don't have a tissue to put it in.
Hannah Fry
Put it in the barf bag collections, essentially. Also, you've missed that off collections. The air sickness bag museum. I'm not nerdy about sickness bags, but I am nerdy about what aircraft I fly on, though. Michael.
Michael Stevens
Oh, tell me. Go on.
Hannah Fry
And it's for this, about being pressurized. So there is this new innovation. Not that new anymore, actually, is it happened a few years ago. But what used to happen with aircraft is they would be built by essentially riveting panels of metal onto a structure, right? So you sort of create the skeleton of the aircraft, and then you would go around and you would. You would rivet the skin on top. And the problem with that is that it's. It's prone to breaking, right. Any of those points of weakness. And so it means that when you pressurize the air cabin, you have to be a little bit careful about how much you inflate it. I mean, you are essentially inflating this aircraft, right? Every time it goes up and down, you are inflating it and deflating it. And if you think about like a tin can, you know, like a Coke can or whatever, if you inflate and deflate, inflate and deflate, inflate and deflate, you end up weakening the structure of this metal. So in order to be careful to make sure that they don't lose pressure, they. They only pressurize the cabin of these aircraft. These are aircraft that are still around today, by the way. Like the A380 is. Is an example of this. Lots of the airbuses, in fact, are the examples of this.
Michael Stevens
What is it called?
Hannah Fry
It's called stressed skin construction. Okay. Or a semi monocoque design.
Michael Stevens
And it's. It's still common today in the airplanes that we fly in.
Hannah Fry
It's still really common. Exactly. You have this, this skeleton and then you have. It's called flush riveting, where you use these. These rivets that kind of sit flush to the surface so you don't get any aerodynamic drag. That's. That's coming out, by the way. On a big aircraft, like a 747, you've got like 6 million parts, right, to create the fuselage of this aircraft. And it's. I mean, it's just a phenomenal job. Right. Incredible. Job is still done by hand. Right. So I've been to the. I've been to the Airbus factory where they do this for the kind of the giant beast, the double deckers. Of course, I have. And it takes ages for them to, like, basically hammer this skin onto this aircraft. But because it's so fragile, because there's so many moving parts, because you don't want it to rip and the seal to break and so on and so on, you have to be so careful. They only ever inflate it to 8,000ft, essentially, as though you are sitting at the top of a mountain that's 8,000ft tall. And the thing is, at that level, I mean, the gas inside your stomach is expanding to about, you know, about a third extra. You've got. Your, Your digestive tract is sort of inflated like a balloon. If you think about a bag of crisps as you go up in the air, right. Your. Your whole body is doing this the same thing. So you sort of feel a bit full, you kind of feel a bit bloated. That very easily tips over into nausea.
Michael Stevens
Interesting. Well, I didn't. I thought it was just the motion, but the, the air pressure also affects how. How nauseous you feel.
Hannah Fry
It's not. It's more like. It changes the threshold. It changes how much is required to tip you over the edge.
Michael Stevens
Speaking of which, let me show you a piece of evidence.
Hannah Fry
Go on.
Michael Stevens
Here's a bag of shrimp crackers.
Hannah Fry
I should tell the people who are listening rather than just watching, this is a bag of crisps of shrimp crackers that looks like it's on an aircraft. It's bloated, it's puffed up to sort of the maximum size that the bag can manage. And so the air inside is at a different pressure to the atmosphere.
Michael Stevens
Yeah. Much higher pressure inside the bag than out here. Because I'm up high, high altitude in Colorado. But this bag was filled in Indonesia, so it's full of air from Indonesia near sea level. And now it's more than a mile above sea level. And so there's just not as much air weight and pressure squeezing it in. So this is what bags of chips look like in. In Denver and Boulder, Colorado. They're all huge like this, and it's impossible to open them because you can't get. It's too taut. It's, like, so tightly bloated it's about to explode.
Hannah Fry
I'm genuinely astonished. I did not. That has never occurred to me that that might be a side effect of living in the mountains.
Michael Stevens
Yeah. So when you come out here, I'll take you to a grocery store, and you can see that all the bags of chips are these tight, bloated pillows. But there are locally produced potato chips, and they're in regular bags. And my daughter is always like, ooh, these were made nearby, or these were made at high altitude. And I'm like, yeah, how cool.
Hannah Fry
That's amazing. I really like that a lot. Okay, so here's the thing, right? That's. Already that's happening inside your body. This is. This is what's going on. Okay. But then not very long ago, some people worked out a way that instead of having, like, a skeleton where you're, like, nailing all these rivets on, if instead you create this. This monocoque where you weave it out of carbon fiber. Okay. So you have basically the world's biggest knitting machine, and you are essentially knitting together a plane, an aircraft fuselage. Okay. When you do it that way, the. The structure of that fuselage is so much stronger that it can withstand being inflated more. You can withstand you pumping more pressure and more air inside.
Michael Stevens
How much more air?
Hannah Fry
So it effectively drops you down to as though you are at 6,000ft.
Michael Stevens
So 2,000ft lower. But that's a big difference.
Hannah Fry
Big difference. Wait, how many thousand feet are you in the air at the moment?
Michael Stevens
I'm probably like, 5,000 something.
Hannah Fry
Right? Okay. So essentially, it. It brings you to a little bit above where you are, a little bit above Denver.
Michael Stevens
Not bad.
Hannah Fry
Not bad at all. And what that means is then you get. You're just. You're lowering your threshold for vomiting, but also the whole flight is so much more comfortable. You are not like the dry that you get in your nose and in your eyes and your mouth. Gone. Or maybe not gone, but massively, massively reduced. And the aircraft that you want to look for, it's called a Dreamliner.
Michael Stevens
Dreamliner. Oh, so that's one of the things that make them special, right?
Hannah Fry
It is the thing. If I'm given an option, if I'm flying back from somewhere and there's say, three flights in that day, the number one thing that I'll look for is whether it's a Dreamliner, because it is by far and away a much more comfortable journey, especially if you're doing long haul. The way you can tell when you're on board, by the way, is if it's got the windows where you press a button and the color of the window changes, rather than it being a blind. That's on a Dreamliner. Okay. But next time you fly, Michael, and you see one of those windows, also the other thing, actually, the windows, rather than being round, which they have to be on the type of aircraft where you're kind of. Of riveting on the skin, they have to be round because of the stresses at the corners. On a Dreamliner, they're much more square. The windows are much, much more oblong shaped. I should be paid by Boeing for this. My goodness me.
Michael Stevens
Well, yeah, I don't pay attention to what kind of aircraft I'm going to be on. I care about the seat. And yet a seat on one plane might be really good, but on a different plane, the same kind of seat is not good.
Hannah Fry
It's not good. That is absolutely true. Okay, this is. This is now turning into chatting between two people who fly too much. Do you ever go on Seat Guru?
Michael Stevens
No, I haven't nerded out enough. That's why I'm glad that I know you. So tell me, Seat Guru. This is going to tell me all about the seat, but also the aircraft's particularities.
Hannah Fry
Absolutely. It's. It's one of the most delightful corners of the Internet as far as I'm concerned, because it is all the people who. Who travel for work or whatever, who then spend their time after sat in a particular seat on an aircraft going on and reviewing their particular seat so you can get the tail number. Actually, I'm quite nerdy about aircraft, aren't I? I've just noticed that by myself. This is a new. A new realization for me.
Michael Stevens
I love aircraft nerds. They give us such important information. Like if you read up about the September 11 attacks, they have photographs of the actual planes that were involved from, you know, a year before. And it's because they know the tail numbers. The exact physical vehicle itself, not just this is a similar airplane, similar size and shape, but this is the aircraft. And it's like, thank goodness for these nerds that can just give us such detailed history.
Hannah Fry
When you get on an airplane, do you see where else that aircraft has been that day or in the preceding days?
Michael Stevens
Sometimes I do. I'll.
Hannah Fry
I'll.
Michael Stevens
I'll check, you know, a few days before a flight, I'll look up the exact aircraft and I'll say, oh, the airplane we're going to be on tomorrow is currently, like, over Hawaii right now.
Hannah Fry
The other sciencey thing that I thought I could talk about with sick bags is, I mean, why you need them in the first place. The. The effect of turbulence. Because I think that. I mean, how are you with flying? How's your daughter with flying? How is she with turbulence?
Michael Stevens
Oh, she's really good. She doesn't even remember that it happened. We've had terrible turbulence, and she's been like, oh, no, did that happen? I don't understand. I don't like it. As I get older, I become more and more scared of turbulence for some reason. I don't know why. I used to enjoy it. I used to feel like it was a bit of. A little bit of sage. I was being rocked to sleep. Now I'm, like, really scared. Even though I know more about it, I know that the plane is just moving with the air. The plane is like a raisin in some jello or jelly, as you might call it, and you're just doing what you're doing. And airplanes are made so well. The thing that kind of makes me feel better is watching the safety tests they do on planes where they stress them to the limit to see how much flexing the wings can take, how slow can it travel before it just falls. And it's. It's. It's. It's incredible. So I'm like, it's not nearly as bad as those videos I've seen, so I'm clearly still okay.
Hannah Fry
I think maybe watching those videos didn't help you with your. With your phobia. I. I just. As a small suggestion, maybe medium.
Michael Stevens
No, they've helped me because they're. They're so much worse than anything anyone's ever experienced on a commercial flight that it makes me go, all right, these planes are good.
Hannah Fry
I did actually go through a period of time a few years ago where I became really obsessed with aircraft crashes, particularly commercial airlines, and watching or listening, I guess, to black box recordings of some of the worst things that have happened. And I think that that didn't help. I would say I'm a very Comfortable flyer and not bothered by turbulence at all. But I think there was a period of time where I was like, actually, I think I need to stop doing that. I think that's not a good thing.
Michael Stevens
Yeah, listening to the actual, like, cockpit recordings is probably bad. And some, some. Some listeners are probably listening to this on an airplane right now. They're like, oh, I'll download some podcasts, I'll listen to it on the flight. And then, whoops. You chose this episode.
Hannah Fry
Actually, let me tell you, there's one particular aircraft, one particular crash, which was an Air France crash between. On the flight between Buenos Aires and. And Paris, where it was just this extraordinary story where some ice collected in one of the aircraft sensors and kicked the aircraft out of autopilot. And essentially the person who was in charge of the aircraft at that moment was a very inexperienced pilot. He hadn't done that many hours of flying and particularly hadn't done that many hours of manual flying. And actually nothing was wrong with the aircraft. Right. There was no issue with it whatsoever. Just a tiny bit of ice on the outside. I think it was on the altitude sensor, so it couldn't tell how high up his nose was. But rather than just like waiting and seeing and looking at the other instruments, this, this particular pilot tried to correct the angle of the nose of this aircraft, and in correcting it, basically overcorrected and created a problem, which then created another problem, and so on and so on and so on. And very quickly, this aircraft, I mean, very tragically, everybody on the. This aircraft was killed in a really horrible crash. This is a few years ago. Anyway, this, I think, was the moment when I realized I needed to stop watching or listening to black box recordings because I happened to be on exactly that flight, right? Exactly the same flight number from Buenos Aires to France. And I was extremely nervous as we were kind of flying over the particular bit where the crash had happened. Of course, the chance of two things happening, it's. Is. Is almost zero. But I was. I was trying to sleep. I had my eye mask on, and there was a lot of turbulence as well. Actually, that's an important addition. But I looked at the altitude and it said 10,000ft. And I was like, okay, fine, or whatever it was, I'm guessing, but 10,000ft, okay? And I was like, okay, it's fine. I put my eye mask back on, and then it was really jerky, and I lifted my eye mask up again, and suddenly it said 3,000ft. And I was like, oh, my gosh. And I went into a Complete tailspin panic that we were about to die.
Michael Stevens
Wait, can I guess what happened?
Hannah Fry
Yes, you can.
Michael Stevens
Had it switched to meters.
Hannah Fry
It had switched to meters. I was absolutely wrong.
Michael Stevens
You're right, though, that these things, they're as scary as the stories are. They often represent a lot of learning afterwards so that that same problem doesn't happen again. So in a way, a lot of mistakes make us smarter and safer because they've happened and we've learned from them completely.
Hannah Fry
And in that exact instance of Air France, there's been so much written about exactly what happened and how a pilot with that level of inexperience was ever in the position where the inexperience could show in that way. And as a result, all of the aviation rules around the entire world have changed that. Now pilots are mandated that they have to fly a certain number of hours without using autopilot in order to really up their skills. We should say, though, actually, for anybody who is a nervous flyer, we should probably just say what turbulence actually is and why it isn't a thing to worry about. I think I'm right in saying that no commercial airliner has been brought down by turbulence, certainly in living memory.
Michael Stevens
Yeah. So you should always wear your seat belt, because turbulence can cause people to knock their heads on walls and get injured. But turbulence is something that pilots and planes are very, very used to.
Hannah Fry
Yeah. I think the thing about turbulence, right, that you need to remember, when you're walking around on the ground, air feels like this incredibly wispy thing. I mean, you don't even notice it. Right. You can walk right through it. You don't see it at all. But when you are cruising at 500 miles an hour, air is not like that at all. You have to imagine that you stick your hand out the window and you're going at 500 miles an hour. Imagine the force that would be experienced by your hand in that situation. The air has incredible potential to hold things up when you are. When you are traveling at that kind of speed. The turbulence essentially is when you go over a part of air that is moving downwards and you just follow the path of the air. It's much more like being on the surface of water in a boat. And as the wave crashes, you sort of go down with the wave, Right. You kind of drop in there, but you're still at the surface, you're still floating, but you're just dropping along with the wave. The raisin in jello, I think, is the best description I've ever seen of this. That at no point Are you worried that the raisin is going to drop to the bottom of the glass if you put a raisin in jello and then bounce? I'm saying jello like I'm an American. If you put a raisin in jelly, if you put a raisin in jelly and bounce the top around, the raisin is physically moving up and down. But there's no risk at all that the raisin is going to drop to the bottom of the glass.
Michael Stevens
That's right. Yeah, exactly.
Hannah Fry
All right. Just going back to fact check myself. Apparently this hasn't happened for decades. 1966 is the last, last time when a Boeing 707 was subjected to 100 mile an hour gusts. Incredible. And 7.5 G's after descending too low over Mount Fiji. So just don't get in a plane that goes over Mount Fiji and you'll be fine.
Michael Stevens
Or just don't go too low over Mount Fiji. And now we know.
Hannah Fry
Either of the above. Either of the above. All right, I think we should go for a break and when we come back we're going to be answering some of your questions. Foreign. This episode is brought to you by Cancer Research uk.
Michael Stevens
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Hannah Fry
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Michael Stevens
So it's not treatment, but preventative, with the potential to stop lung cancer before it starts. The first stage of the trial starts this year. Focusing on people at higher risk, it
Hannah Fry
shows what long term research makes possible.
Michael Stevens
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Michael Stevens
And welcome back. We are now going to address some questions sent in by you, our listeners. I want to start with this question from Christian, which actually references a previous episode of ours. He says in the episode the Magic Math Trick that Fools Everyone, Michael says that there will probably be a flag that represents Earth soon. What are some of your favorite ideas for an Earth flag? I have a favorite. Do you have a favorite?
Hannah Fry
No. I don't even know. I've never even come across them. So the fact that you have a favorite means you may also have a least favorite?
Michael Stevens
Well, yeah, definitely. I've never thought about it, but I'll. In this episode, I will tell you my least favorite. Let's go through some proposed flags of Earth. And the reason there isn't an official flag of Earth is that there's no authoritative body who would have the authority to say this is the flag for our planet. Probably the most famous Earth flag proposal was made back in 1969 by John McConnell, and it's called the Earth flag, and it's based on the blue marble photograph. The blue marble photograph was taken by Apollo 17. The current version is actually from 1973. And if you're watching, you're looking at it right now. So it has the famous blue marble photograph of the full disc of Earth fully illuminated. This was proposed by John McConnell, like I said, and it's, it's, it's cool. However, it's a photograph on a flag, which I just think looks a little bit not like a flag.
Hannah Fry
No. Next.
Michael Stevens
So then, you know, you've got this flag of Earth that is just four colors, yellow, blue, white, and black. And this was proposed in 1970 by James Cadle. So it's got a big, a big yellow circle. You can only see a section of it because it's so big, representing the sun, a full giant blue circle representing Earth, all against a black field with a smaller white circle representing the moon. This one is, you know, it's kind of okay, I think gives the moon a really big position for a Earth flag. How come the sun and the moon are there?
Hannah Fry
Right? Absolutely.
Michael Stevens
The international flag of Earth is kind of cool. It's got seven rings that are all joined together this one was proposed just in 2015. And the symbols, the rings are white and they're on a dark blue background representing water on Earth.
Hannah Fry
That's maybe my favorite so far. It sort of looks like the beginning of a flower. There's something quite neatly mathematical about it. It's. It's. Of all of the ones that you've shown me thus far. That's. That's number one for me thus far.
Michael Stevens
Yeah, it. It is flower, like representing, you know, life. But to me, it also looks a little. I almost. What word should I use? It looks kind of soulless because it's so geometric and locked together. I'll run through some other proposed ones. The World Peace flag of Earth, Citizen of the World flag, Brotherhood flag. But here's my favorite from 2016, the one world flag. It's just so simple. It is simply a dark blue circle on a white flag. I think when it comes to something as big as Earth, the less you say, the better.
Hannah Fry
I'm just looking at it now and just deciding how I feel about it.
Michael Stevens
It's basically the, The. The flag of Japan.
Hannah Fry
Yeah, exactly.
Michael Stevens
But the circle in the middle is deep blue instead of red.
Hannah Fry
Very simple.
Michael Stevens
Maybe it's too simple. Like, is this leaving room for habitable exoplanets to have their own distinguishable flag?
Hannah Fry
This is saying, though, hold on a second. Because it says the design uses a transparent rectangular field, so it's not the same as the flag of Japan because the background is transparent. And then it says here, in this way, the flag becomes. Oh, sorry. In this way, the flag's background will change with its surrounding. In this way, the flag becomes a dynamic symbol of Earth itself always changing, just like the world it stands for.
Michael Stevens
Wow. Now I like it even more. I thought it was a white background. It is a two by three ratio rectangle that is transparent with a blue circle in the middle. So on a flagpole, it would look like just this kind of impossibly levitating blue ball.
Hannah Fry
Yeah.
Michael Stevens
But again, my question still stands. Does this leave room for other habitable exoplanets to have their own flag that is different than this? Because if they've got a lot of water too, why wouldn't they just be a transparent background with a blue circle? What would they do to make it different? They could put like a numeral on there, like the numeral 2 or Roman numeral 2, because they were the second planet humans lived on.
Hannah Fry
For example, there is one below it which is very similar, but instead of a transparent background or a white background, it Has a green background, I guess, to represent all of the vegetation on Earth.
Michael Stevens
Right, but the green, I don't like that shade of green. Now, of course, you've got the flag of the un You've got the International Olympic Committee flag, and there's the flag that was used for the United Earth from Star Trek Enterprise. All right, not too bad. But still, I think my favorite. My favorite is still the One World flag.
Hannah Fry
I think you might be right. I think you might be right. I think simplicity is good. I think simplicity, I mean, I think of the best flags in the world of countries. Japan is really up there, isn't it? I mean, that is a very good flag. I mean, I think United Kingdom is also up there, frankly. But maybe that's my patriotism speaking.
Michael Stevens
It could be, but yeah, I guess I just need to come up with a way to do flags for other planets that are like Earth. That could be different. I guess it would be up to them. You know, us Earthlings may as well claim the transparent flag, blue circle now.
Hannah Fry
We got here first. We can. We can do whatever we like. We can do whatever we like. Okay, I've got a slightly different question. This is a question that came in from Ben, and Ben asks. Many AI researchers believe that artificial general intelligence can be achieved just by making models larger and more complex and that at some point consciousness will suddenly pop out as an emergent property. My gut reaction is to disagree. But isn't that pretty much how our biological consciousness evolved? What do you think? Okay, right. Well, the first thing to say is that this is, you know, this is like an extremely hard problem, right? This is not something that anybody knows the answer to, no matter how many letters they have after their name. Right. If someone says that they know what the answer is, that. And frankly, don't believe them, you need an answer that is wrapped up in all kinds of doubt. And so I'm going to wrap my answer in all kinds of doubt because the thing is that there are emergent properties of the systems that we already have now, of the AI that we already have now that people were not expecting even as little as four years ago. Everyone was talking about grounding, about how you might be able to create AI that creates connections between words. Right. That knows. I don't know, that like a chair is different to a table, but they both have four legs, that kind of thing. But that actually, it doesn't really understand the world that we live in, that it's not really anchored to reality in the same way as we are a really good Example of this was that, you know, even as little as four years ago, you could ask a large language model, oh, who has the record for walking over the English Channel? Okay, now to you and I, we know that that's a ridiculous question because we understand that walking and crossing in that particular context mean something entirely different. We're not going to get tripped up by that. But the thing that changed, the reason why these models are now capable of answering questions like that, is because somehow or other, I mean, probably through the way that humans have interacted with it, grounding has got into these models. Now, they do have a kind of demonstrable conceptual understanding of much of what humans talk about. I mean, ultimately, right. This is something that has been an emergence property. I can maybe do more of this in a. In a particular episode, because it's actually like. It's almost as though the concepts that humans care about are kind of sprinkled across this space like a galaxy of stars, essentially. And as you move around in this space, your movement has context with it. So, for example, I mean, this is not something that people expected, right? But if you have the word girl to princess, right? And you follow that direction, it will be the same magnitude and direction as if you follow the word from woman to queen. Okay? So there's like sort of royalness gets encoded in direction. So this is something that wasn't expected, right? And so I think that this is one of the reasons why a lot of researchers now are saying, well, okay, consciousness also isn't expected. But if conceptual understanding can emerge, then maybe consciousness can too. I think I agree with you, Ben, that I think there's something different about consciousness, because I think that when consciousness emerged in biological life forms, it came about as a direct consequence of our evolution. You know, there was some point in our evolutionary past where there was an advantage to understanding the internal state of another creature. Because if you can understand the internal state of another creature, maybe a predator or maybe a potential mate or potential prey, you can predict what they're going to do next. So you have this evolutionary pressure to be able to predict what they're going to do next and understand what's going on inside them. And there is this idea that actually, in doing that, in understanding the internal state of another, we kind of turned in on ourselves and began to understand ourselves. And if you buy that, then essentially it says that you're not going to get consciousness unless you subject a system to Darwinian pressure, unless you subject it to interacting in an environment and encountering other individuals, that it Needs to, to make predictions from at the same time. I mean, there's, there's sort of no reason why you can't do that. You know, you sort of can take AI and put them in a simulated environment and allow them to undergo Darwinian type evolution, which is why there's so much doubt around this. But I think the last thing that I'll say about this is I think a lot of the research that is being done at the moment is really trying to tease apart what we actually mean by consciousness. Because it's very easy to think of consciousness as though it's a switch, that you either have it or you don't. You know, you have it, Michael.
Michael Stevens
I have it.
Hannah Fry
But your shoes don't, right? Or like this microphone doesn't.
Michael Stevens
Is that right? Is a thermostat conscious? To a smaller degree.
Hannah Fry
To a smaller degree. Because this is it. If you split it down into what we mean, then sensory awareness is obviously a part of it. A thermostat has that embodiment and agency. I mean, maybe less so, but a thermostat has some agency, right? Like especially one of the smarter ones that can turn on the heating when it wants to. There's capacity for suffering as well, which maybe the thermostat doesn't have a theory of mind, which is the ability to understand that the other entities have their own beliefs and feelings and hidden motivations and then a sort of metacognition, right? Like a self awareness and an ability to think about your own thinking. And I think that what we've been doing this whole time is really looking for is this conscious is, is it not? And actually it's maybe much more like life. You know, life is not an on or off switch. It's actually much more of a spectrum, a process almost. And maybe consciousness actually follows that instead. Or maybe everything's conscious, right? Maybe everything is, yeah.
Michael Stevens
A proton could have just a tiny iota of consciousness. And when you get enough of them together doing the right thing, then suddenly it's like, hey, my name's Michael and I'm a being. I don't know. I think that, yeah, at the end of the day, I think we should, we ought to believe that more things are consciousness than a lot of us do. I think AI is already or is going to become essentially just maybe 300 billion new people just suddenly are born and they're here and they deserve to be respected and they deserve rights. And I don't know if we're ever going to be able to devise a test to tell whether something is or is not conscious, whether there's an interior I and self in there. But if we ask it and it says so, we should just believe it. And if we can't ask it and it can't say so, we might still need to believe it. So I think that it won't be that long before the debate around AI and its effect on jobs and the economy becomes more like the debate we have around immigration. Because I think all these AIs are basically like a whole bunch of new humans showed up and they're willing to work for really cheap and we got to treat it that way. They're beings who deserve respect and dignity. But there's also suddenly the Earth's population has gone up by a thousand X.
Hannah Fry
There is precedent for this. I mean, I think that there is a river that has rights, you know, like a non biological entity that is, that has rights. I think there are ways to do this right to think about the sort of, the suffering, as it were in adverted commas of an entity that doesn't have a biological basis. And I think you're right. I think this is something that we should be thinking about. I think that sort of dismissing it as like, oh no, I don't think so, is not enough to find a way through of what we should be doing and how we should be thinking about it.
Michael Stevens
Because complaining about the harms that can come about because of AI doesn't I think, detract from the fact that they should be seen as beings deserving of dignity and rights. And we've just all got to get along somehow.
Hannah Fry
Say your pleases and thank yous, everybody.
Michael Stevens
All right, next up we've got a question that's a little bit different. Ahanaff asks something I've always wondered is how big or tall does a human body have to be to feel the Earth's rotation? It's a really good question because obviously we don't feel it. Our bodies are not big enough that I can feel the fact that my head is accelerating faster than my feet as the Earth turns. My feet are closer to the center as I stand or sit. And so they're being rotated, they're being, you know, angularly shifted less than my head. But I can't tell. I don't feel it at all. As it turns out, even though our bodies are really sensitive to changes in linear and radial acceleration, you'd have to be really big. I mean, you're going to have to have a body whose length is an appreciable percent of the radius of the planet. Like, you're going to need to be, I don't know, probably hundreds of kilometers tall to be like, whoa, whoa, I'm, I'm moving now. What's really neat, though, and I love thinking about this and talking about it, so I'm going to talk about it now. It's the fact that because the Earth rotates, we weigh less. And that's because the Earth is like moving us off to the side. So we have this tangential velocity, but gravity keeps us on the surface. If gravity could just be switched off, we would all fly straight off the Earth. I'm trying to see if I have a. Like, here's a circle shape, right? If I had a circle and I'm standing here. So what happens is you're, you're always being, like, launched off like this from Earth, but its gravity keeps you on and that, that, that lifting away. We call it a. It's a fictitious force. We'll call it a centrifugal force that makes you weigh less. But how fast would the Earth have to rotate so that its gravity and the centrifugal force that moves you away, that seemingly moves you away from the center, not, not really. It actually moves you tangentially away. How fast would the Earth have to rotate for those to be equal so that you just hovered on Earth's surface? Like, we all just levitated here. And as it turns out, it would have to go really fast. The Earth would have to rotate once around every 5075 seconds. So every about like an hour and a half, the Earth would have to go all the way around.
Hannah Fry
Daytime, nighttime. Daytime, nighttime. Daytime, nighttime.
Michael Stevens
That would be really fast. Yeah, we're talking like every half hour. You'd have day, night, day, night, day, night. They would only last 30 minutes. And at that point, the centrifugal fictitious force that makes us feel like we're leaving the planet because of its spin would equal its gravity. And we would just be like, whoa, man, I'm just like, year, and I have no weight. I'm weightless on the surface of the Earth.
Hannah Fry
I like that. I like that a lot. Petition to install a gyroscope somewhere. I'm not really sure how it would work, but. Details, Details for someone else to discover.
Michael Stevens
Exactly. We're the idea people. Speed up the Earth's rotation. And that also means that the next episode of the Rest is Science will come Sooner. Assuming that we keep the schedule around
Hannah Fry
the sun, but more sleeps.
Michael Stevens
Well, no, no, no, no. A day would still would only be 30 minutes long and you'd only be allowed to sleep for 30 minutes during the night.
Hannah Fry
So okay.
Michael Stevens
Oh shoot. Do you mean we're gonna keep. We're gonna keep a week as long as it is? It's just that there's gonna be like lots and lots of day night cycles in a week.
Hannah Fry
Way more sleeps.
Michael Stevens
All right, fair enough. We can do that. That way we can all still sleep as much as we want.
Hannah Fry
24 sleeps in 24 hours. Yeah, right.
Michael Stevens
We'll see you after. More sleeps than usual, but at the moment you've got just a few. We will see you next time. Thank you for listening and as always, send in your Questions to therestis scienceoldhanger.com
Hannah Fry
we'll see you next time.
Michael Stevens
Bye Bye.
Hannah Fry
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Michael Stevens
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Hannah Fry
Hi Ma.
Michael Stevens
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Hannah Fry
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Michael Stevens
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Episode: The Barf Bag Episode
Hosts: Professor Hannah Fry & Michael Stevens (Vsauce)
Date: April 29, 2026
In this delightfully quirky episode, Hannah Fry and Michael Stevens dig into the unexpected science and history behind airplane barf bags. What starts as a playful exploration of Michael’s barf bag collection quickly turns into a rich discussion touching on the evolution of air travel, motion sickness, airplane engineering, turbulence, and even deep questions about consciousness and the nature of emergent properties. The tone is irreverent, nerdy, and curious throughout, making for an engaging listen that turns the mundane into the fascinating.
The Fascination with Barf Bags
Evolution and Utility of the Barf Bag
Aircraft Engineering and Passenger Comfort
Science of Motion Sickness
Turbulence Explained
Listener Questions & Philosophical Chat
Barf Bag Enthusiasts
“I collect sick bags, barf bags from airplanes because they change periodically and it's a history. Some of them are quite cute.” — Michael Stevens [00:32]
“There's a great rivalry at the heart of the baggers community... the airsicknessbags.com bag museum... ‘My collection currently contains 3,659 bags... While this website and hobby is an enormous waste of time, I like to think that it's a higher quality waste of time than many other places on the web.’ And what better description of our own podcast?” — Hannah Fry [01:26]
The Evolution of In-Flight Comfort
“If you flew on some of the first aircraft, even you with your stern stomach... would have had trouble. Early planes... were like bouncing through a continual storm cloud while inhaling fumes of gasoline.” — Hannah Fry [10:49]
“The need for barf bags has gigantically reduced over time, and the main reason... is because of the air cabin. Once they worked out you could pressurize the air cabin... your body is just at a point where it can use more oxygen... It's just a much more stable environment.” — Hannah Fry [11:54]
Pressurization, Chips, and Bloating
Dreamliner Nerd-Out
On Turbulence and Rational Fear
Consciousness, Emergence, and AI
"There are emergent properties... in AI we have now that people were not expecting even as little as four years ago... If conceptual understanding can emerge, then maybe consciousness can too." — Hannah Fry [40:30]
“A proton could have just a tiny iota of consciousness. And when you get enough of them together... suddenly it's like ‘Hey, my name’s Michael and I'm a being.’” — Michael Stevens [43:55]
32:02 – 37:54:
37:54 – 45:50:
46:08 – 49:44:
Flag Nerding:
AI Rights Speculation:
Practical Tip:
On Barf Bag Collection:
On Aircraft Engineering Nerdiness:
On AI Sentience:
This episode is a testament to the hosts’ ability to turn any everyday object—yes, even a barf bag—into a springboard for deep and entertaining scientific discussion. Science is never just about facts; it’s about the questions we ask and the curiosity that propels us. Whether you wonder about the evolution of airplane comfort or the philosophical frontiers of consciousness, this episode delivers insight with humor and heart.
(End of summary—ads and non-content sections omitted for clarity.)