The Reality of Being Santa

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1:21Hello and welcome to The Rest is Science. I'm Michael Stevens, creator of the Vsauce YouTube channel. And I'm Professor Hannah Fry. Welcome to our Christmas edition. Yeah, look at us. We're in our Christmas jumpers. I have actual tinsel. You have actual tinsel on yours? This isn't very Christmas themed. It's like a cat in a potted plant. But my wife bought matching jumpers for me, her and my daughter for my daughter's first Christmas. And it's what we wore. And so for me, it's very, very Christmassy. Yeah, it's the real true heart of Christmas, right? the fact that you get to be connected with family.

1:57That's right. And today we're going to get to the heart of Christmas. I'm talking physics. I'm talking Santa Claus. Okay. Now there's an old chestnut, an old roasted chestnut where physicists talk about, could Santa really do it? Okay. How could Santa visit every single child who celebrates Christmas across the world in one night only? And without magic or without some kind of fancy alien technology, it's not possible. Obviously, what Santa is doing is compressing space-time, right? In front of the sleigh, he's using an Alcubierre drive. He's expanding space-time behind him. He's like surfing the resulting bubble fast and the speed of light.

2:40Classic Santa physics. Easy. True. And I think the Alcubierre drive would also protect Santa from G-forces. because just for those who aren't familiar, and now Cubieri Drive is a hypothetical method of transportation where instead of propelling yourself through space, you change space itself. You can compress space ahead of you and travel light years at a time in a blink of an eye. And you're not violating physics because you aren't moving faster than light. You aren't moving anything faster than light. You're just changing the shape of space. Exactly, except that it's not hypothetical because we know that that is the only way that Santa could be.

3:15It must exist because Santa somehow manages to do it. That's correct. Without such a drive, Santa would be experiencing 17 ,000 times Earth gravity forces as he twisted and turned. I guess the thing is Santa hasn't had much competition over the years, right? Probably because he's mastered how to warp space-time. But if you sort of take that away, was there a point in history where Santa could have existed using only the powers of physics that are available to us mere mortals? Today, Hannah and I are asking, when could a regular person have competed with Santa? When could you also have visited every living human in one night and given them a gift?

3:59Because right now you've got eight billion people on the earth, right? This is too many. We're all spread out. We're all over the place. Too spread out. If we rewind the clock a little bit, I think we might be able to give Santa a run for his money. All right. So first things first, let's understand who Santa is. Like, let's rewind the clock. Where does it all begin? The story of St. Nicholas. I think everyone sort of knows that that's roughly the lineage of Father Christmas. But he is quite the historical figure. This is a Greek bishop in the fourth century, a real person. He was kind of famous for defending Christianity, also for giving gifts.

4:37But specifically, there are stories about him giving gifts to a poor father who had three daughters, didn't have any money for a dowry. So Sir Nicholas decides to drop off bags of gold just to make all their lives much better. But one version has him throwing the gold in through the window and it landing in their stockings that are drying by the fire. Oh, so that's where the stockings come from. That's where the stockings come from. This is kind of real person. I mean, I think some of it is slightly embellished over time, I'll be honest with you. When did this happen? When was St. Nicholas supposedly alive?

5:13This is a fourth century around about. He also was present at the First Council of Nicaea. And there was this big heated theological argument between him and one of the priests. And St. Nicholas lost his temper, punched him in the face, which means that that tradition of Christmas arguments is also stems directly. Oh, I love that. Stems directly. I love that. One of the other stories about him, by the way, is that there was some innocent men, three innocent men, sailors, I think, who were about to be punished, beheaded in a town square. And there's a story that apparently St. Nicholas appeared out of nowhere, teleported, in my opinion, and appeared at the moment of beheading and grabbed the sword of the executioner, saving these innocent men from being executed.

6:11Hannah, is anyone really innocent?

6:16No. Thank you. We can investigate that more in a future episode. So this is all happening, you said, in like the fourth century. That means the 500s. Okay, so this is St. Nicholas. We're talking 300. We're talking the 300s. That's where we are. So the 300s, which is the fourth century since time zero. Yeah. And golly, that's a long time ago. Yeah. So here is the thing. Okay. Imagine being like a famous person now, right? Like, you know, Taylor Swift, right? The biggest star in the entire world. Every day. Now imagine it being 2 ,000 years later, 1 ,700 years later, and her still being so famous that it's recognised around the world.

7:00Her sort of, the kind of metaphorical version of her is still recognised around the world. That is phenomenal work. I mean, what a guy. There's one more thing actually about St Nicholas that remains a great mystery to this day. So his bones are in Bari in Italy. They're in this tomb. And actually there was this really big, dramatic event where people went in and stole his skeleton seven years after his death. It came under the control of the Turks and then took it to Italy. Anyway, his bones were put in this tomb in the year 1087. And ever since then, every year, it secretes a liquid from the inside of the tomb.

7:47And every year they go in and they collect the liquid. It's about 50 mils of liquid. And the Catholic Church say this is a supernatural event. The secretion of the bones of St. Nicholas. I have never heard of that before. They call it manna and they dilute it with holy water and sell it. And they sell it. It's probably condensation, I've got to be honest with you. But don't worry about that. Don't let that stand in the way. It might contain some traces of human remains. Not just human remains, Santa remains. Santa remains. I also think that it could just be that he wants everyone to know that his bones are magical before he sort of left his earthly body and, you know, became the Santa that we know today.

8:28This is really deep. I mean, I really love how immortality can be achieved if you're willing to allow your ghost to like completely change into something different. You know, I think St. Nicholas was probably like, yeah, Christmas is about Christ and the birth of our savior. And now he's like the counter choice. It's like, well, you know, So, because Santa doesn't do any religious stuff. It's not like he... He brings happiness to all men and women and children. That's a pretty religious thing, isn't it? I mean, I grew up in like the kind of church that was very much like Santa is essentially an arm of Satan.

9:07Because it distracts from the true message of Christmas and the grace of the Lord. Wow. And instead we all go, ooh, let's buy things. Let's give gifts. Right. And the gift came from Santa, not Jesus. Like, he's kind of like the boring part of Christmas. What nature was that? Well, it would have been like non-denominational Protestant, bordering on evangelical. I was brought up Catholic and we were fine with it. You guys were fine with it? Fine with it. I mean, my Irish mom less so, but the church in general was okay with it. Right. This is the guy we're up against, right? He's got a long old history.

9:44He's been famous for millennia. He's got magical bones. He throws coins into stockings through windows. He teleports executions and saves innocent people from death. You know, you're up against a lot before we've even started with the presents. I think we just have to accept that we can't compete with any of that stuff. But actually, you know, Hannah, Hannah, Hannah, I plan to compete with that. I plan on also having weeping bones. There are services that you can pay for that will make sure your bones create liquid for millennia. Okay. But anyway, the bones aren't really what we're after. We're after delivering gifts to every human in one night.

10:28We're going to have to find a time in history when there were fewer people. The first thing we talked about, Hannah, was population bottlenecks. These are moments where, for various reasons, the human population shrunk or couldn't grow, and it stayed somewhere really low. The first thing I thought of was the Toba bottleneck, which is hypothetical. Big volcano in Indonesia, right? Yeah, what, like 74 ,000 years ago. It affected the climate massively. The main theory is that the ash cloud would have changed the weather, the amount of sunlight getting to Earth, the temperatures on Earth, and it would have been very hard for early Homo sapiens to live and to thrive.

11:13So the population of humans on the entire planet may have dropped as low as like 70 ,000. Because when you say that there was a lot of ash from this volcano, I mean, we're talking we're talking this is the apocalypse, basically. I mean, this is like 2 ,800 cubic kilometers of material. Basically enough ash to cover the entire UK in a layer that's taller than Big Ben. I mean, it's phenomenal the amount of ash that this thing spat out. But there are some people that think there was like 10 years of volcanic winter, that, you know, plants would have suffered, that, you know, access to food more generally would have been really difficult.

11:50And there was a theory in the 90s and early 2000s that actually almost all of humanity was wiped out by this event. Yeah, we almost didn't make it. In fact, the original theory was that at some point, maybe 74 ,000 years ago, there were only like a thousand humans on Earth. And we are all the descendants of those thousand who survived the Toba super eruption. Now, that's a sad story, but we're bringing it up because as tragic as that moment could have been, it would have been wonderful for us trying to compete with Santa because there's only a thousand people. And, you know, if you could ride around on like a reindeer, all right, just or have them pull a sleigh, they can sprint at like 80 kilometers an hour, all right?

12:42You could visit a lot of people in a night because you've got how many hours of night? like 30, more than 30 hours. Well, yeah, I mean, it depends on how far north you are, I guess. It does depend on how far north you are. That's how long the night is going to be. Luckily, you can do this in the winter. So, OK, if you're in the northern hemisphere, you're going to have a much longer night. You can follow that Terminator line of night and day as it goes around Earth. And once you get back to where you began, guess what? You've still got a whole night ahead of you. Yes, because as long as you don't cross the date line.

13:14So if you start like, you know, right on the dateline, but ever so slightly to the west of it and you only travel west, you have 24 hours to get back to that same point and it's still be the turn between night and day. But then you can wait there, not cross the dateline all of nighttime. So if you've got if you're, you know, far north enough where you have sort of 16 hours of nighttime, then you've got 24 hours plus you have 40 hours. Wow. As long as you start at sort of 4pm, I mean, you're going to struggle to sneak down people's chimneys without being spotted if you're doing it at 4pm. But in theory, you know, you can use the night to your advantage.

13:51One of the big counter arguments about the Toba super eruption, the kind of catastrophe that supposedly shrunk the human population, is that when you look back in the genetic record of people, you don't see this population collapse quite at the same moment as we know that the volcanic eruption happened. Because that ash, it left a mark in the geological record. You can see exactly how far. And we see dust all the way over to East Africa, right? So there's kind of enormous spread from Indonesia to East Africa. But what you can do is you can take people from around the world and you can look in their genes and you can basically ask yourself the question, if I walk backwards in time, how far do I have to go before two randomly selected people have a common ancestor, before their genes demonstrate that they have a common ancestor?

14:41And by doing that and doing that repeatedly with people all across the earth and then looking backwards and backwards and backwards further in time, you can see that there were definitely moments where the population of humans really shrunk. Not as much as leopards, by the way. Do you know this about leopards? No, what happened to leopards and when? Leopards is like the best example of population bottlenecks. Leopards are so genetically similar to one another that you can take a skin graft from any leopard you like and pop it onto another leopard and it will not be rejected. Do we know when this bottleneck happened?

15:15Yes, we do. And we know how small the population got as well. Just on that point, though, that idea that a leopard can't change its spots turns out not to be true. you can just borrow them from another leopard um the the uh we know it was about 10 000 years ago you can tell this in the genes um and they reckon that something happened that meant the population of leopards went down to about seven seven right there are seven common ancestors around about that among all leopards and it's only 10 000 years ago that that happened now in humans you can do the same thing you can see there's these moments of decline but there isn't one that directly lines up with the moment that the Toba super explosion, super eruption happens.

15:58Yeah, and that's disappointing for our quest today. It is. Also, when did these human bottlenecks potentially happen? There are plenty. There are plenty over, I mean, hundreds of thousands of years, right? So if you're going back 300 ,000, half a million years ago, you know, then you might be looking at populations that are much more manageable in terms of as far as Santa is concerned. Great. However, I think we're now entering the territory where we need to define what we mean by person. Because if you go back 500 ,000 years, I don't think there are any Homo sapiens. There's Homo erectus. But as far as we know, and we're getting into really speculative territory here, Homo sapiens with the anatomical features that we have today, you and I and everyone listening, that didn't emerge until like 300 to 200 ,000 years ago.

16:56And this specifically is big brain, small jaw, upright. Yeah, the brain is like above the eyes, not just right behind it. Like a very, a very small skeleton. In fact, I love this theory that human intellectual abilities came about because we evolved such slight dainty skeletons that cooperating together was our best bet, that we needed to plan ahead and assign roles and invent rules and morality because we couldn't just go out there, grab an animal and kill it on our own. We didn't have claws. We didn't have big teeth. So we had to design tools and work together. Because these are the two things that set us apart from any other species is that we're cognitive and we're social.

17:39That's right. Yeah. Okay. So 300 ,000 years ago we're talking. But even then, I think that the population of Homo sapiens then was like, we're still talking pretty small. Tens of thousands, maybe hundreds of thousands. I know. And here's another problem. When we look at the evidence we have, like the oldest Homo sapien fossils ever found, that's not like, oh, guess what, guys? All the humans alive on Earth used to live in this, like, one cave. They spread. Like, spreading out was just, like, their thing. We've got ancient, ancient oldest Homo sapien fossils found in Ethiopia and Morocco. and you cannot travel that distance on a reindeer in a night.

18:22I've got a few options. There's, of course, there's elephant birds. These, you would find these in Madagascar, not far away from the cradle of humanity. Are they extinct now? They are extinct now. They were 10 feet tall. They're 200 kilograms. They were around until about a thousand years ago or so. Couldn't fly, technically, but still, they're elephant birds. I mean, what more do you want? They were big enough. You could ride them. And I guess they were probably pretty fast. Okay. So you had means of transportation to like go quite a distance. You could. I mean, there's also, there's the giant ground sloth.

18:59That's another option that was around 25 ,000 years ago. Where do they live? You find them in North and South America. So quite far away. But I think we should allow this prehistoric, non-magical human to like travel, bring a giant sloth over to where the actual Homo sapiens. are. They can prepare. We're bending the rules ever so slightly here. Yes. Well, on that note, should we go for a break?

19:38All right, welcome back. I just went on the record saying that in the year 275 ,000 BCE, a person could have done what Santa does by themselves. That humans may have been close enough together and small enough in number that you could have visited every single one of them in one night. However, that's like so speculative. I mean, we don't know enough about human evolution to say that there weren't some, I don't know, some human ancestors that had already migrated into Asia and then they like evolved cognitively and anatomically in the same way thousands of miles away from those in Africa. We just don't know.

20:15But look. Don't caveat this. What are you doing? I'm caveating because there are so many theories and there's so many unknowns. And I think it's actually really exciting that we still have these questions to answer. Ultimately, I just love knowing that it may have never been possible to visit everyone in one night. I'm still stuck on how geographically spread out they were. Because I think if you're talking hunter-gatherer situations here, you're probably talking about sort of family pods of 10 to 20 that will probably have their own territory sort of geographically distinct from one another so I think even if you are on an elephant bird or a giant sloth or whatever it might be I think getting around all of them also actually you know early humans homo sapiens homo erectus whatever it might be were nomadic so you couldn't even have like a map of where they were and be able to go and find them in the same place.

21:12You know, these people were moving around all of the time. So I think you would have found people, even in the earliest days, spread out across the entire continent of Africa. I think you're probably right. I don't think that, again, it's not like a couple chimpanzees gave birth to a Homo sapien and they were like, what? And then you were like, oh, cool, I've only got one gift to give out tonight. We're talking about like ape species like Homo Heidelbergensis and Homo Rhodesiensis, who slowly became more anatomically like modern humans. And they didn't necessarily do it all in the same city, all in the same camp.

21:50There's also Neanderthals that feed into this. I mean, Neanderthals are sort of in the Middle East at this point, while the Homo sapiens are in Africa. Every human has about 2 % of Neanderthal DNA, but only if you have non-African ancestry. And it's because the Neanderthals were in Europe, they were in the Middle East, and as Homo sapiens came up through Africa and then sort of went off to the rest of the world, that's where they interacted with Neanderthals. Neanderthals didn't go down into Africa. For this to work, for a person to visit every Homo sapien, they've got to do it before homo sapiens leave leave before they're in eurasia or beyond um because you just can't cover that distance in a night they reckon it wasn't very many who left you know in fact if you take somebody if you take someone from china um from modern china and you take someone from i don't know europe south america basically anywhere else in the world take two people from around the world, not Africa, and compare their genetic codes, they will be more similar than if you take two random people from Africa and do the same thing.

23:02Wow. Because really a small number of Homo sapiens left and all the rest of us are descended from that small number. Whereas in Africa, where humanity started, where Homo sapiens came to be, there are so many distinct pockets of genetic groups that there is so much more variation within Africa than without it. That's incredible. So maybe, maybe you could just be Santa standing at the sort of edge of Africa through the Middle East being like handing people out their Lego as they go past. Maybe that's what happened. Maybe that's why they all left. They were like, guys, someone's giving out free pinches of red ochre.

23:41We just got to go up north. Free beads. Should we talk about the types of gifts that actually would have um would have been handed out in 275 000 you'd say well yeah i mean i i've said like i kept thinking that it's going to be like a bead it needs to be something small because you got to carry around a lot of them yeah i think there is quite a lot of evidence that beads were given as gifts like a very long time ago maybe not quite 275 000 years ago but definitely far back in time because for a really long long time we sort of thought that symbolic art started in europe with sort of 40 000 years ago is the earliest evidence of of kind of cave paintings that sort of thing but actually there is um a discovery that was made in biz moon cave in morocco this is maybe 140 000 150 000 years ago and are these tiny little sea snail shells that have got little holes through them as though they uh they were strung through something so sort of like as a necklace basically they were used as beads and you can be certain that the shells didn't just wash up there because they were found way too far inland sort of hundreds of kilometers and um they also show these microscopic wear patterns around this hole kind of proving that they've been been strung on this cord and they've been they've been jangled together and the idea is that these were sort of given as status symbols so so they must have been traded because they carried they just had traveled too far a distance must have been traded and gifted um and yeah the The idea is that they would signify who you were, whether you were married, whether you were not, you know, your status within the hierarchy, that kind of thing.

25:16So that would have made quite a good gift, a beaded necklace. Yeah. And it wouldn't have weighed a lot. So even if there were hundreds of people that you wanted to give them to, you could carry them all on your cheetah or giant ground sloth. Yeah. One of them, I think, another good thing that you could give that would make prehistoric man slash woman extremely happy. would be a miniature hand axe. Do you know about the archaeologists that have found these? These are absolutely amazing. So in particular, in Wolvercote, this is in the UK, archaeologists have found these axes, and they are absolutely tiny.

25:53They're like this big, right? Five to seven centimetres, basically the size of a matchbox. And they are like perfectly made. They're perfectly symmetrical. It's not like they're sort of, you know, were big axes that got shrunk down. They were deliberately made to be that size. And, you know, they've been napped to like this absolute perfect level of precision. They're also totally useless. I was going to ask. Yeah. Completely. I mean, if you're thinking about sort of butchering mammoths and chopping wood, I mean, this thing is not it's not doing anything at all. So in 1999, there's these archaeologists, Maric Cohn and Stephen Mithin, and they proposed the sexy hand axe theory.

26:33Is this the idea that it was done to show your skill and your ability as a craftsman? Sexy hands. Exactly right. Yeah. Exactly right. And isn't that really what gift giving is all about? Showing how good you are as a gift giver? Aren't I thoughtful? Aren't I skilled? I didn't buy you a cake. I made you a cake because I'm skilled. It shows your worth and your value. So when are these miniature hand axes from? We're talking a long time ago, like 300 ,000 years ago, maybe even older. Wow. Okay, so that shows that appreciating gifts is very old. Appreciating skill. What's the best gift that you've ever given, Michael?

27:17The gift of life to my daughter. Ah, great answer. Great answer. I've given a lot of bad gifts. when I was just dating my now wife, I thought she really liked mechanical pencils. She talked about how she liked them a lot. So I got her like really nice mechanical pencils, right? Like fancy ones. And she was not amused. I think that's because you and I are stationary pervs. And clearly, clearly she is not. Well, yeah, I think she just needed a mechanical pencil to do drawings on patterns. And then I'm sitting here like, oh, yeah, well, what if I got you this special two-stage pencil sharpener and da-da-da.

27:55And she's like, no, no, no, no, no, no. I don't like them in that way. Tell you what you could do for your special prehistoric center. What? Maybe you can't leave out some mince pies. There's little metal trays that they come in. That's not a thing yet. But alcohol is. Alcohol absolutely still is a thing, even as far back as 275 ,000 years ago. and we know this because well for one thing fruit if it is left to ripen for too long becomes alcoholic essentially it just happens right just happens right one to four percent ethanol you can find in fruits just as they are left to ripen and other apes other monkeys will happily consume fermented fruit in order to get very drunk you uh you also get elephants sometimes doing this um breaking into breweries that's something that occasionally happens basically animals love getting drunk it's uh it's a thing um also humans the clue that we have prized alcohol for a very long time is that we are amazingly good at detecting it we can detect even the slightest little whiff of something being alcoholic which i mean frankly that beer radar came from somewhere.