Vampire Physics, Mathematics & Evolution

out whole populations in an instant. Hey, welcome to Stuff to Blow your Mind. My name is Robert Lamb and I'm Christian Sager, and we just began the show with a quote from Mary Halab from her article Vampires and Medical Science that is printed in the February two fifteen issue of the Journal of Popular Culture. Why, because we're going to talk about the physics and mathematics of vampire

blood sucking today. Yeah. Now, if you're a long time listening to Stuff to Blow your Mind, uh, and you visit our website, perhaps you're familiar with the Monster Science the video series. You know from all these avenues that we've we've touched on vampires before in the past. Uh, this time, we're we're largely going to deal with you know, a little a little physics, a little um fluid mechanics, a little mathematics, as well as just taking you through

the the evolution of natural world vampires as well. Uh. But yeah, certainly we love vampires. Here's stuff to blow your mind. I think as as uh you know, as a people humans uh cannot get over the Yeah, as you know, we are fans of and did an episode on the Strange, that's right. Uh, and it was interesting.

There was stuff in the research for today's episode that brought up the strain for me that I didn't find when we were doing research on the strain um, like in particular different kinds of tongues and bats and how they consumed blood. Yeah. I mean, we could really just do vampire episode after vampire episode and find just probably

a whole podcast out there vampires. I mean, and even when you're getta do this, our fascination with it, just the mythological appeal of vampires, you know, despite our best efforts to just totally kill it with with with a steak in the party, with a steak in the heart, especially a cinematic steak in the heart. Through some of just the sort of trite rehashes that we see over and over again, we still can't get enough. There's still something just hideously romantic about the vampire. Oh yeah, I'm

always on the lookout for a good new vampire movie. Um. And I think the last one that I saw, did you see Byzantium? I did not think. I have it in my cute. It's an interesting movie. It's not it's not like mind blowing or anything like that, but it was. It was a nice take on the vampire mythos um. Well, like, I love how the Strain has done and we talked about this in the Strain episode, how they've like really taken into account like anatomical differences in nature incorporate and

incorporated that into their vampire mythos um. But yeah, I just as a horror fan, or maybe just as a cinema fan, I'm always waiting for somebody to find like the next cool hook on it. You know. I'm like, I'm thinking of Near Dark a lot of fun. Yeah. Um, Bill Paxton roll on that, yeah, Lance Hendrickson too, pretty much everybody from Aliens, Yeah, yeah, it was a Katherine

Bigelow film. It was. Yeah. Now, for the purposes of this episode again, we're gonna we're going to limit our discussion of vampires to physics, mathematics, and evolution, um, you know, basic real world biology without getting very you know, without doing too much the way of dragging in anymore folklore, mythology, film history, etcetera. And really the best place to start, in my opinion is um is by looking at bats. I mean, bats are pretty much the vampire bat is

one of our most prevalent modern examples. Uh. The the main parallel between the idea of a blood drinking human uh in fiction is a real life blood drinking um vertebrate. You know. It's interesting about that that I learned doing research for this episode was I had always assumed that we called them. Sorry, I had always assumed that the vampire myth came out of people having witnessed vampire bats.

I did not realize that it was sort of like the hydra that we've talked about recently, that it was actually the myth that came first, and then when we discovered vampire bats, we gave them the name. Yeah, that's right, because these areas where you many of the areas in the world where you had the vampire mythology that you didn't actually have any blood drinking bats. There are million South America and and part of that has to do I mean, most of it has to do with some

of the limitations of blood drinking. So let's talk about the bats and the birds. They have a great deal in common. They're very different organisms. And the birds we have the avians that emerged about a hundred and fifty million years ago in the Jurassic Period. They went out

to fly, swim, trot, burrow all over the world. Meanwhile, mammalian bats date back between seventy five and a hundred million years and uh, it's harder to say because um quote, bats are one of the most diverse groups of mammals today, they are one of the least common groups in the fossil record. Bats have small light skeletons that do not preserve well, and we have very little information on the

early evolution of the group. And that's from a University of Edinburgh page that I'll link to in the landing page for this episode that deals with just sort of the basic evolution of bats. Have you ever been to or heard of the bridge that's in Austin, Texas that just has like millions of bats underneath it and if you like hang out there at the right time of night, you can just see them all swarming out. I've seen

video of it. I went to Austin on vacation two years ago and it was awesome, Like we got to see it and it was really, uh, really something to behold. But also apparently are co workers who were in Austin recently for south By Southwest. We're gonna try to do a video on it, but the bats wouldn't come out. They were not cooperative. Um, so both bats and birds learned to fly in their own ways. Uh. And there

are there are other fascinating examples of their conversion evolution. Uh. Several dozen bats species and more than three hundred species of hummingbirds evolved to resemble each other anatomically and behaviorally solely because they existed in similar environments and exploited a similar resource, that being nectar. Yeah, so nectar feeding bats

they have pretty strange anatomies as well. Like I think we hyper focus on the vampire bats, but really I think it's something like three out of like a thousand and one hundred bats species drink blood, so it's kind of interesting that we focus so much on that. But so these nectar feeding bats, there's one called the orange nectar feeding back, or it's a Latin name is Lancophilia Robustah.

It can extend its tongue out to drink the nectar, and it has grooves on its tongue that undulate like waves, forming a conveyor belt to just basically conveyor belts drag the nectar up to it. It's a it's gullet. And the way, the reason why is that these bats way fifteen grams each. They have to drink one point five times their own weight every single night. So that means that each one of these bats has to visit somewhere between eight hundred and a thousand flowers every night in

order to survive. Um. So it has to be really quick. That's why it's evolved this crazy tongue. It only has two second visit, so it's just like boom, flies into the flower, sucks out the nectar with its crazy tongue, and flies away. Now imagine something like this with somebody who drinks blood, right, um, And in fact there's also a bat in South America that has a tongue like the vampires in the strain that we had talked about.

Its tongue is one point five times the length of the rest of its body, and it reaches all the way down its throat between its sternam and its heart. So it's just this huge organ that's shooting up out of its body through its mouth, grabbing this is a nectar, drinking one again, grabbing the nectar and the yankee back down. Um. But those are nectivores, right, and we're here to talk

about san guivores. Yes, sanguavar is the blood drinkers. And there's little or no convergence between birds and bats when it comes to drinking blood. And now there are birds that occasionally or even frequently feed on on blood. Um. Vampire finches of the Glastical Sylands occasionally feed by drinking

of the blood of other birds. Meanwhile, you have, you know, plenty of examples of birds that feed on ticks and other ectoparasites on large animals, and they sometimes cross that line between dining on stolen blood and stealing it for themselves. But none of these birds is an obligate cyclevore an obligate blood drinker. The vampire bat stands alone among all vertebrates, is the only aerial or terrestrial obligate blood drinker. It's

all they consume aside from their mother's milk. And so, to give you a comparison to those nectar drinking bats that I was talking about earlier, blood is actually pretty skimpy when it comes to protein and fat. The kind of energy they need water, so vampire bats get almost no fat at all out of it. Subsequently, they have to consume this is different from the nectar ones. They only have to consume half their weight in blood each

night to stay alive. Imagine if you and I had to do that, if we had to consume half our way in blood, Like that's even uh fantastic by the imagination of vampires, right, Like, that's a lot of blood. And we're gonna get to that later on when we talk about the physics of actually drinking blood from a thrall if you're a vampire. Yeah, I think that's certainly, certainly something that's very important to keep in mind here though, is that that blood is not this just font of

energy and resources. Uh, there's there's very little power in the blood and for a vampire bat and certainly if you're gonna extrapolate that and say a vampiric human, if they're going to make this their soul um feeding method, if this is gonna be the only place they get their energy, it is it's pretty skimpy. You're talking about

living on the very edge here. Yeah, and there was a you know, I think it's easy for us to say, like, well, for for us, you and me, because we love our monster science, it's easy for us to go, yeah, there's science to be had there, but it's easy for us as a culture to go, well, vampires, that's just some made up stuff. Uh, there's there's nothing real going on there. But in fact, there is a collision in the seventeen hundreds between medicine science in the myth of the vampire um.

And this comes from that Mary Hallab article that I quoted at the beginning of the episode Rural People's in the seventeen hundreds, they relied on traditional medicine to ward off vampires, and to them, taking an interest in something like the supernatural was their means of conducting scientific inquiry. So what they would do is they would pay a fee to somebody who said, yes, I'm a vampire expert, I have been trained, uh, and I can prevent the

spread of this right. So an example, UM, and I wonder I thought of you when I was reading this, because I'm sure you've heard of this before. In a Serbian village, people thought there was a deceased soldier named Arnold Paul and he kept coming back quote unquote as a vampire and attacking villagers. Uh. And what happened was, you know, it resulted in two waves of sort of a vampire panic that lasted one was three weeks and

one was forty days. After he died. They eventually had surgeons show up uh and disenter his audi so they could attest yes, this is indeed a vampire. Uh. And so one of these doctors, his name was Dr Fluckinger and Dr Flukinger, brought this story to Western Europe where it was actually debated amongst a lot of medical professionals, in particular in Germany. And there was also a doctor John Polar Doori, who wrote an influential story about vampires

that has actually uh. Mary Shelley talks about at the beginning of Frankenstein. These two events together by two medical professionals may have been responsible for establishing vampires as fantasy and not as rural, you know, a supernatural fact. Uh. And so basically the German academics and doctors debating this led to uh, the original Pope Benedict in seventeen forty nine declaring these vampires are superstition, they don't actually exist. And that was sort of the beginning of it of

us acknowledging it as fictional. Interesting, Now, I know a lot of you are probably wondering. Okay, So so we we've already talked about the rarity of of a of a mammal drinking blood is its soul of form of sustenance? Uh? And and we we talked about what a poor form of sustenance blood is. So how do we get to that part via evolution? Why are there so few species that do it well? The vampires in question likely emerged twenty six million years ago, but we already mentioned bat

fossils are not too easily come by. Uh. And sure we have a few fossil vampire bats, including a thirty percent larger does Moodius dracula. Uh Yeah, that's that's a wonderful. And but but these are these are total vampires that you know, we don't really have those transitional forms. Uh. And and then part of this comes from the fact that you see so many of these bats that have delicate bones and they're tropical region. Fossils of them are rare. So we just have a few hypotheses as to how

vampires emerged. Uh. One hypothesis is that the proto vampire bats that they these ancient species, they weren't quite vampires yet they fed on blood and gorged ectoparasites found on large animals, much like these various you know, tick eating birds, you know, oxen and rhinos and whatnot. UM. So we're you know, we're talking fat fall off the rump, prehistoric kicks um. And you know earlier we mentioned the blurring the term fall off the rump. They fell up. They're

just they're just there. There's there. It's say, once they're full, they can't hold on anyone. Yeah, they're and they're mostly the blood of another species. Um. And they're just there for the picking. And we already mentioned that the blinds are often blurred between parasite eater and just just an eater of blood. And it's the same deal here, supported by the fact that se bats um are insectivores, so you know, anttis are iractants. But still you get the

idea they're used to eat. These are the type of creatures that they eat already. And then if certain bats began to depend more and more on on parasites, you can see where the transition could take place. Plus, there are anecdotal reports of vampire bats preying on vampire moths, which is interesting. And and yes there is a vampire moth and you'll find it in Malaysia, uh, the Ural

mountains and also southern Europe. Uh. And just like imagining as we're explaining all these various different types of species with vampire in front of their name, that there's like so, I'm sure there's gotta be a fictional account there somewhere of like u mythical vampires, but they like turn like a bear or something like that. And then you've got like vampire bears duking it out with vampire humans. You know who's gonna eventually survive on the food chain, Right,

vampire bats are eating vampire moths, what's eating vampire humans? Yeah? Yeah, vampire whales vampire whales. See that that has not been explored at all yet. I think we've gotta we should copy right that. So Bill Shoot wrote a wonderful book a titled Dark Banquet Blood and the Curious Lives of Blood Feeding Creatures. Highly recommend anyone interesting this topic check it out. I noticed that this book was cited in multiple of the resources that we're looking at for this. Yeah,

it's it's a great one. It's it's one that's you know, very readable for a general audience. And he goes into not only vampire bats, that he goes into various insects as well, so it's a you know, a thorough engaging exploration of the topic. But he points out that mutual grooming behavior may have played a role in the evolution

of vampire bats as well. Because the vampire bats are highly social, they spend five percent of their time grooming one another, and Shoot suggests that they may have had their first taste of blood consuming each other's kicks and bedbug species, so you know it kind of you know, they're in this situation with like, oh, these are great, we should go try and get more of these, and we just get it direct from the tap yeah, yeah,

take out the middleman. Now. It's also worth noting that bat expert Brock Finton disagrees with another great name Brockton. I'm a I'm a fauna expert. Brock points out that ectoparasites are small, ecto parasites are difficult to find on other animals, and vampire bats are restricted to the Americas.

So those impossible problems with this hypothesis. But Finton presents hypothesis too, and that's the proto vampire bats fed on insects and larva crawling around the wounds of large prehistoric mammals. You know where I first heard this theory was on Dr Anton Jessup's episode of Monster Science. So we talked about vampires because that was where I learned the term

mega fauna. Yes, yeah, mega fauna the large you know, today we pretty much are down to, you know, just elephants is like the really great example of megafauna in the old days when they could be sustained and you had plenty of other creatures as well. With a whale, Yeah, yeah, exactly similar. Yeah, because you have this large creature, this just bounty of resources, it gets a cut on it, right that becomes a just an area of increased economic activity, a lot of organisms trying to feed off of it,

and then who's gonna feed on the feeders? Well, then perhaps that's where this this begins. The vampire bats or the proto vampire bats, they volunteer and jump in there to get some of the the goods. So there's a lot of back and forth in this hypothesis as well. And then finally there's an arboreal feeding hypothesis, and this is the idea that proto vampires foraged in trees, feeding on small vertebrates, and over time they evolved uh to

capitalize on larger prey uh that they couldn't kill. At first, they bit the animals that slept in the trees, and eventually they adapted to prey on ground dwelling animals as well. Because that gets into how vampire bats actually work. If they swoop down um uh and they they open up just a small opening on a like a sweeping cow or what have you, and then lap the blood. Yeah,

they're not draining and cow dry. And it's the interesting connection here to the studies we're gonna be talking about later, as the premise really is the same for like, uh, the vampire human myths, right, which is is that you know, essentially it's not economical for a vampire bat or a vampire human to drain you dry. They need to come in do it quick in such a way that you

probably won't even notice, right. And that's where that like comparing it to the nectivores is important because they've only got that two second windows. So if a vampire bat just flies up to a cow, makes a small incision, laps up a little bit of blood for a couple of seconds, and then flies away, cow is probably not even gonna notice until the next day when it starts itchin. Yeah, because it's also it's very much a stealth activity again there,

it's kind of like a business model, right. They can only extend so much energy to pull off this heist and still make a profit. Like the vampire bat cannot get into a situation where it's going to try and wrestle a cow. It's not gonna work. It has I'd love to see it, Yeah, And I suppose vampire bats are also probably not cooperative enough that they've come to the point where like they're just gonna swarm onto a

cow and just drink it dry, you know. Yeah, well I think it's one of those things where one vampire bats gonna get away with it, Like one one criminal can rob one store, all six criminals cannot rob the same store at one competition for resources. Al Right, So this brings us to the the process of drinking blood itself. How do you drink blood as a mammal, as a vampire bat? And then what could that possibly tell us about how it might work for a human um? And uh,

it's a lot of this is chemical. Um, the vampire bat makes a small cut and laps, does not suck the blood. And uh, while the average wound inflicted by a vampire bat would likely stop bleeding in one to two minutes, they are key ingredients in the vampire bats saliva that interfere with clotting for several hours. So you you're talking about really a complex chemical cocktail in the saliva.

So yeah, we would definitely have to assume that any kind of vampire, uh, humanoid sized vampire would also be producing an anticoagulant. That's right. I wonder if they get I haven't watched enough of like True Blood or anything like that, but I wonder if they get into that with those shows. I do not remember from all my time watching True Blood. Um. Now, now, some people, some experts also speculate that there's often a pain killing and or skin softening enzyme in the saliva as well as

the bat will lick before they bite. So again, the saliva is it's just a cocktail of essential blood drinking chemicals and that they lick, they cut, then they lap it up and those times work very similar to that nectivore I was describing that. It's just kind of like this, uh conveyor belt. It's just like working like a piston. The way that it licks. When you watch the slow

motion videos of these things, it's kind of stunning. Yeah, it causes that this movement causes the blood to flow along a pair of grooves on the bottom of the tongue and into the mouth. There's even a cleft in the lip that allows the flow of blood. And wasn't there like a period of time where some scientists thought that that U the flaps on their nose, we're what

we're making the cuts themselves and things. Yeah, there, yeah, there was, But of course it turns out that all most of that has to do with that called location has nothing to do with feeding. But but yeah, if you're just looking at these these crazy looking or gamy back faces, you could I can imagine one producing that theory like, oh those look kind of sharp. Maybe they kind of slashed their face back and forth in a open a vein. So again, think of this though, is

as a heist. It's really a high stakes heist for the vampire back um so that they're they're absorbing, Uh, they're taken in this blood and absorption of the of the of the water that makes up the ingested blood. This carrious to the kidneys, noon to the bladder for excretion. So they may have to fly off at any moment when that cow begins to wake up, wake up and they're peeing. Yeah, because they're having to process this in real time that a sudden weight gain could be lethal.

Can't carry a one out around that much useless water, so it needs to just pass it as quickly as possible. Um, So these cows are getting back golden showers at the same time. You can put it that way. Yeah, there's that they end up having to to urinate a little

as they're feeding. Um approximate and approximately the blood volume consume is excreted as urine in the first hour after feeding, so again you gotta you gotta get rid of the useless water as quickly as possible, and still at the same time, there's a constant dehydration risk because we're talking about a lot of urine here, and mammals break down amino acids into uria in order to prevent the toxic

build up of ammonia. The vampire batch digestive system cranks up more and more with feeding to eliminate the waste, but in doing so, this is just constant risk of dehydration.

So they're just constantly one step ahead of the hydration, which is another reason that you you only find vampire bats and very very moist envied Okay, And that's uh somewhat similar to what we talked about when we looked at the science of the strain, Right you remember, the vampires in the strain are just like I think, as they're feeding, they're constantly emitting ammonia or something like that, right,

as like a waste product. And that's I haven't watched a lot of the TV, so I don't think they tracked them that way, and I think they do that in the TV show. Don't they like they tracked the ammonia stains with like UV lights or something like that. Yeah, yeah, yeah, I believe they do, and that that would fit in nicely with this with the research here del Toro once

again looking at his anatomical manuals. Yeah so um so. Again, it just comes back to this idea that that it's a very very high risk fringe lifestyle that the vampire bat is left with. They can't really store up a lot of fat. They can't. This another reason you don't find vampire bats and cold environments. They can't. They can't se question themselves away for the winter and a cave because they constantly have to get that blood. They're more

like a hunting bird than a true carnivore. If only vampire bats could keep thralls, if they could keep like, like uh, like maybe a mouse sized thrall in their nest and they just drink a little bit here and there. But the problem is they have to drink so much, right, Yeah, indeed, if they could do something like they need a lot

of thralls. Yeah, they would need a lot of thralls or set up some sort of honeybee environment where they're they're essentially making like blood honey and storing it away. I like that. Maybe they'll get there one day, but for now, we we've got this earth vampire bats. Yeah. Well, that actually leads pretty nicely into uh, what really brought

us into talking about this. We're gonna take a quick break, but when we come back, we're going to talk about a brand new study that looks at the physics of how we would drain blood from a human being if they were our vampick Thrall. Alright, we're back, and we had so far we're looking at we're trying to imagine

a humanoid vampire. We're looking at an emaciated, stealthy nonsperrato that slips into your bedroom, licks your neck with us, and then with a strange groove tongue, then slices it with a specialized tooth and then lapse up the blood before and peas a little bit before slinking away into the night. But how long does this non sperato in question have to fee? Well, the answer has been discovered, and it was actually just discovered last fall, and uh,

actually Robert has written about it already. We were inspired by this. We both saw the study on the same day. Oh no, actually, you found it, did I? Oh, I was the one who found that. You were the one who felt okay, and we we we have pitch meetings here and at the beginning of the week we both pitched the story and then the uh you know, our editor said, you guys gotta do this, and I said, well,

it's monster science. That's Robert. Robert's gonna do the vampire long as we get to do it for the podcast. And I ended up writing about Batman Superman did about the various Superman Vatman uh interactions, So you got the bat kind of a little bit. Yeah. Yeah. So but that was the inspiration for us to dive into this because we said, this study is so cool, let's extrapolated outwards and really look at the physics of it. And turns out a lot of people have done research into this,

so let's talk about this study. Yeah. This comes to us from the University of Leicester in the UK. It was published in the Journal of Physics Special Topics. Uh, and it's a whole team of researchers here worked on it. They decided to just weigh in on just how much blood a human vamppire would drink and how long it would take them to drink, because I don't think this is anything anyone really uh put a lot of thought to in the past. But there are you know, there

there are going to be limits here. I hope people making vampire movies and television going forward to take this science into account and use it in their calculations, including the mathematics that we'll talk about after this too, because there's a large your game at play here. But let's we're gonna zoom right in and look at a vampire lord and their thrall. Premise here being that you don't want to just drain your thrall dry, right, You want to keep them on hand so that you've got a

constant tap of blood available. Yeah, you want to be able to come back. However often I'm guessing, uh, you know, if you're going by like blood donation standards, it's gonna be over a month between visits if they're playing by the rules. Yeah. Well, and that's assuming that this humanoid sized vampire doesn't have to drink as much blood uh comparative to its body weight as a vampire bat does.

Otherwise they just have like a basement full of people that they're drinking from constantly, right, So the first thing they had to decide is, yeah, how much, um, how much blood are they going to drink? And so, based on information from the American College of Surgeons Advanced Trauma Life Support or a t l S program, the researchers figure that that amount would be about of your blood volume. Technically, that is that that's the upper limit of a class

one hemorrhage. So hey, if your thraw out there, do not let your vampiric overlord talk you into a class to hemorrhage. That's over unless he's willing to make good on his promise. And actually the gist here is that it's similar to the vampire bat scenario in that the percent is from the model that a vampire would be able to drink enough secretly, uh that you wouldn't notice

and it would be able to get away. So like, maybe it sneaks into your bedroom at night and it just like opens a vein and it starts going is the cap before your heart rate starts to change and you would notice effects on your circulatory system. Uh. And in particular, the model for this study, they have their vampires specifically drinking from the external kartid artery. And they've also modeled the A order and coatid arteries as being smooth tubes when the assumed air pressure of one standard

atmospheric pressure unit. So obviously this is not uh true to life, right, Like, we don't all have perfectly smooth tubes with the exact perfect atmospheric pressure in it. But hey, we got to solve these problems somehow. So, as we previously mentioned, they decided to go with the bat model of blood drinking makes more sense than looking mosquitoes, right, they were looking at free flowing lapping as we've discussed, rather than sucking from a pair of point five millimeter

neck punctures. And then they calculated the average diameter of the orda and the five connected arteries, as well as blood pressure and the heart driving velocity of the flowing blood. So they really got into the biology and the fluid mechanics of the whole. But they didn't They didn't factor in anti coagulants, So this is assuming that there's no anti coagulant chemical applied by the vampire. Interesting, I didn't

notice that during my first read of this. Now, a few equations later, the researchers determined this that any self respecting vampire needs six point four minutes to drain a polite point seven five liters of blood from his earth draw. So to put that in perspective, it takes less than an hour to give point four seven leaders during a blood drive where they take eight of your blood. Yeah, but they don't drink any of it. I know they drink. Well, we don't know. I mean they might be that's what

those curtains are there. Yeah, I mean, in a sense it is. If it is used, it is it becomes a part of another person. So it's as well in a sense it's it's concerned. Now, these results are based on a couple of mathematical assumptions that the people doing the research made specifically about human biology. So I'm gonna

run through these real quick. The first one is that the five arteries that split out of our a orda have total even thickness, which you know, I doubt that's true, and everybody the diameter of the aorta is four centimeters, which is that's known as the known carotid artery diameter. Right. That seems big to me. You think about that four centimeters.

I guess that makes sense, but it's a major highway to. Uh. The velocity of blood coming out of your a or to has a mean speed not not like means speed, but at average speed of point one milliseconds. Uh. The internal arteries have a point five centimeter diameter. The average human blood pressure would be one millimeters of mercury, and the average density of whole blood is one thousand sixty

kms per cubic meter at room temperature. So they thought of it all, uh, and they calculated it out based on the average human body having a total of five liters of blood inside of it. Okay, alright, so that gives us, uh, that gives us some you know physics grounding on exactly how much blood is gonna be taken,

how long uh it takes to consume it. Yeah, so to crunch that at six point four minutes, that scene, I mean, I guess, like maybe I'm a light sleeper, but that seems to me like I would notice, um, but you you know, like I'm thinking, no s Feratu style, like sneaks into the room and there's a a woman whose neck is is just a positioned just the right way. Um,

I don't know. Maybe they just don't notice. Yeah, I mean, as long as she didn't have a neck pillow or anything, or if she's you know, she's sleeping under the covers completely and neck pillows like modern enemy of Vampires never even thought about that, Yeah, because he can't very well

just pull that off, right. So all right, that's the micro version of it, right of how the drinking of the blood would work on one vampire on one human if they were trying to drink it real quick, get away with it without getting caught, or just have a thrall on hand and keep them alive. Let's broaden this

a little bit. So we turned to Anissa Mary Ramia, who is at the University of Ottawa in eleven and for a mathematic model ling of infectious diseases class, wrote the paper vampires do they want to suck our blood? And I want to I want to take an aside here to say I was disappointed in you, and I am disappointed in Ramia for spelling want with a W. It should have been do they vant to suck our blood?

Because that would have that would have been because I believe you had the do they want to suck our blood? Or want to suck your blood in the title of the original piece of the story we just talked about, Okay, so Ramya's goal here was to use mathematical models to deduce whether vampires could exist. In particular, could we as human beings live alongside a creature who wants to suck

our blood? So is it a sustainable creature? Yeah? So she looks at she proposes several models and I'll present them here, and she uses theoretical data based off of the television show Buffy the Vampire Slayer. So she's working off of some of the premises within that mythos, because you know, vampire mythos varies from yeah you gotta you gotta choose one and if you gotta go with one, I guess it seems like a pretty good one. Yeah. So um, she starts with the first model that was

actually written by somebody else. It was written by Dr Sohan Gandhi and Dr Costas J. I'm gonna butcher this name ft the EMU sure sorry, uh cost Us. Anyways, that they had this really cool paper called Ghosts, Vampires and Zombies Cinema Fiction Versus Physics Reality. It was published in Skeptical inquirer in seven and we're gonna call this, or at least Ramia does the s V model. Okay,

this is the bare bones model. So going with statistics that say that the present human population is six point nine billion people in rising, these guys argued that vampires never existed and could have never existed, because if they did, the human race would have been wiped out in three years.

The way that they figured this out was by using a mathematical concept called geometric progression, and this is used to calculate the interest in economics and finance, or to find the quantity of decaying radioactive elements in geology and physics. So cool application of pre existing model. The constraint there is that the world population is constant, so there's no

in their study, there's no birth rate or death rate fluctuations. Okay. Uh. It also assumes that there is a constant rate that vampires turn humans into other vampires, only doing so on the first of each month. So I don't know why that would be particularly the date. But so the vampires have all gotten together and said, okay, we can only do this on the first aga. Uh. And so this susceptible population would decline over time, while the vampire population

would increase at the same time. At that rate, there would be no humans left on Earth after three years. Now. One of the obvious problems I've i've I've had when I've encountered this kind of argument before is that you're assuming the vampires are not making some efforts to keep

themselves from destroying each other. Because even if there is you know, an unsustainable species, I mean, you can make arguments that humans in our present form are also an unsustainable species, and you know, and maybe we're doomed, but also maybe we're able to stave off extinction by curbing our self destructive tendencies at least a little bit. Yeah, Ramya keeps adding complexities like that into the various models, but she never gets to that one, which is, Yeah,

I like that idea. Like that, vampires, which are you know, based off of our anatomy and our psychology and Russia, would probably have as much in fighting as we humans do, right, They wouldn't just all cooperate perfectly in order to drain blood together? Yeah? Not surely. Not everybody gets the good blood now, but not everybody gets to have as much

blood as they want. So she extrapolates their data out to the second model, and this is the SVR model, and it includes data for the rate that humans are turned, the rate that humans are killed by vampire, as well as the birth rate and the death rate uh, and as well as all non human related death rates for vampires.

And that wasn't um extrapolated on other than I think that that is just maybe it's vampire on vampire violence, like you accidentally like walk into the sun or something like that, UM, but there is She later does get into human on vampire violence and how that would factor into it. So her next one, and this is a the SVR plus model. This is her third model. UH. It's basically that humans are aware of the existence of vampires and they actively hunt and kill them, and it's quantifiable.

There's a rate that we can quantify how fast humans can kill vampires. So that would mean as an employed vampire hunter in this scenario, you have a quota that you're expected to hit it each month, and there's no reason you shouldn't be able to hit it. And not only that, not only are all the vampire hunters expected to meet their quotas, but then there's also a slayer that is more efficient at killing vampires than any of the other hunters. So this is factoring in the Buffy

methods obviously. So that's on top of all of the other data predictions in the mathematical models presented so far. We had two more models to go. Oh, I really hope one includes blade. Would be awesome if they're like and then blades there, I think she would just she would just be ice skating uphill with that one. All right,

we'll cut that little bit of awkwardness alright. So, yeah, Model four does not include blade, but it adds in the rationale that it's not in vampire's best interest to turn every single human that they drink from, right, And this kind of goes along with the other study that we were just talking about with that drinking. So I think we can assume that that's kind of how they're

working here. Uh. And the reasons why, well, there'd be too many dead bodies that would arouse suspicion first of all, but then there would also be an increase in the competition for human blood resources, and then that's probably where you get the in fighting between vampires. So it uses parameters that in order to be turned. You have to both be bitten by a vampire and then you subsequently have to drink a vampire's blood and then you turn into a vampire. Yes, and that's certainly the model we

see in a lot of vampire fictions. Yea. And the last one, uh, she calls the predator prey model, and this uses this as an actual population dynamic mathematical theory called predator prey uh in. In biology, the idea that the carrying capacity of a given environment is the maximum number of a particular species that can be supported and sustained indefinitely, given that food, water, and other necessities are

all available in that environment. And it was previously approached by a guy named Dr Brian Thomas in two thousand two in a paper called Vampire Population Ecology. So she cleaned that up and applied it here. I love that we are not the only ones who are hungry. No pun intended for vampire science. Yeah, there's there's a legacy here of of sort of epidemic consideration of vampires. So the first case here represents that human and vampire populations

eventually go extinct. The second case that she shows are when vampires are extinct but the human population hovers somewhere near its carrying capacity. And the third case is where human and vampire populations are capable of coexisting. And the important thing to notice here is that the human equilibrium population does not depend on its own carrying capacity. However, the vampire population does depend on the human populations carrying capacity.

So basically, there needs to be a constant influx of human population in order for vampires to have a sustainable coexistence with us. Otherwise we go back to scenario number one where they drink us dry in three years and then what are they left with. It's like that movie what is it called Daybreakers, the one with Ethan Hawk where everybody is a vampire. Um. So, yeah, the human population doesn't depend on its own caring capacity, the vampire

population does. We are not large enough to support a vampire population. So I think by looking at this mathematical model, we can deduce that there aren't vampires. Okay, maybe mathematically you don't have to. You can take that neck pillow off tonight. Nothing is going to drink your blood. Although I will point out, and this is a note in her actual paper, she says this does not take into

account quote large scale supernatural events like the apocalypse. So she admits, look, there's not a lot of data here for her to work with, but she's basing off the TV show. Sure, if somebody out there wants to go and watch every Buffy episode and note the frequency of vampire encounters, feeds, kills, and turns, you can apply that

in these models and extrapolate the data outward. And well, what I like about these studies is they kind of give you a starting point and from there you can sort of tweak the vampire mythos to make it more sustainable or more believable, or throw in certain behaviors or safeguards. They're they're gonna help it make sense. This is what I feel like del Toro did. Yeah, he maybe didn't sit down with these mathematical models, but like they think of stuff like this in that show, you know the

practicalities of a vampire invasion, especially upon New York. Yeah, and also looking at it in the strain, Uh, looking at it too is what you can have the organism, and then you're gonna have sort of offshoots and mutations that can be less sustainable and therefore our risk to

both the humans and the established vampires well. By applying these models, she concluded that if an outbreak of vampires were to break out in an area like say Sunnydale, California, where people were generally really aware and there was a slayer involved, and this is not counting hell Mouth, she said, no supernatural events exactly, it would be less likely uh than an endemic that would occur in a population like

somewhere like where she lives, Ottawa. Uh. And she says, look, there's no slayer in the population, and Ottawa is generally unaware of vampires, so it might be a problem there. But she takes into account and this is where it gets crazy. She applies what she calls the g factor to a locale and this is how much garlic is

in particular areas. And the way that she does this is she takes Google Maps and she plots out all the swarm of shops that are in Ottawa, and she scientifically says that the reasons the scent of garlic would make it difficult for vampires to navigate through a populated

area are because of these swarmer shops. She plots it on the map and then she even gives each store an effective radius and The way that she mathematically computes this radius is based on the rating of the restaurant, it's popularity and therefore how much garlic you could assume

is in each diners system after they leave. So as they're leaving the restaurant, they're creating this radius because they've got like a certain amount of garlic in their blood and on their lips, and that the vampires would smell that and basically like veer away from it. Okay, So there are certain there there would be certain cuisines that and and therefore certain geographical regions the vampires would just have to avoid, Like they just could not go to Italy.

They are parts of China, they would not be able to get a firm foothold, and they have to really go to those Icelandic countries. Yeah, yeah, yeah, And she finally recommends she doesn't break down the math on this, but she says, you know what might also be a good idea is bless all the bodies of water in town. That way, it would make it difficult for the vampires to cross them. Uh, And I think they don't they do something to that effect in uh in the strain

or is it just that they can't cross moving bodies. Yeah, they plan it at Which is another which is an often overlooked a little detail from the Vampire Folklores is that they can't cross moving bodies of water, and they I think they play into the strain that it might have something to do with like essentially their little worms

something like that. Yeah, and I think, if I remember correctly, I hope this isn't a spoiler for the TV show that the way they get away with it isn't what they just like hop on the back of like subway trains that are going underneath the rivers. And yeah, well you know another bit from from Vampire Folklores that's rarely explored, certainly in the scientific literature, but also in fiction is the idea that they're obsessed with with knots and uh

and like intricate fabrics. I think the only bit of fiction that I've seen it used in UH is habit. I don't know if you know when Larry Fresden, I believe, No, I don't know this one, Okay, yeah, it's it was an old indie picture, kind of a slight like nineties indie remake of Dracula, but very much a in be filmed with an indie vibe, and there's a scene where the vampire is transfixed by you know, some sort of

knotted fact. Interesting, so they're just like constantly tying their shoes. Yeah, what's the situation is that if you want to VAMPI you want to protect yourself from a vampire, just hang like an intricate knot or some sort of woven thing outside of your house. The vampire will come to it and then they're just transfixed by it and they start messing around with it. Then the sun comes up in their toes. I wonder if that's connected to knots of garlic. Oh,

I don't know. Maybe maybe just double up on the hunt exactly. Yeah. Well that's it. We got vampire math, vampire physics, vampire evolution. I think we've figured it out. So what do you think vampires possible? H me? Uh, well, so certainly if we based some of those hypotheses for vampire bats off of human humanoid vampires, you know, maybe they were drinking blood off of mega fauna and they

but then they went into the shadows. They've been sneaking that fifteen percent off of us for a long time now. But the only way that they would be able to get away with it is if they kept themselves in check with that fifteen percent. Otherwise, Uh, they would either kill the entire human race or we would figure out that they're there and we would hunt them down. Yeah, they for them to exist, it would just be this very stealthy, very strategic and and just and also just

very dangerous position. Um, you know, like the vampire bats. It would just be it's a heist with high stakes and they have to they have to carry it out just so in order to avoid capture and extermination. Well, I'm gonna sleep better tonight. I'm probably gonna sleep better than I have since I was a little kid and I saw that episode of The Amazing Spider Man that we're Dracula showed up. So um, thank you to the scientists involved in all this research. Yes, we can all

put aside our garlic knight pill lives tonight. All right. So so there you have it. Hey, if you want more on this topic other topics, go to stuff about your mind dot com. That's where we'll find a landing page for this episode. Um, various bits of vampire content. You can just throw vampire into the search of oar. There you'll also find links out to our various social medi accounts such as Twitter and Facebook and Tumbler also Instagram now and we're blow the Mind on most of those.

And if you're a vampire and you have a secret method for getting away with drinking more than fift percent of a person's blood in one sitting, please write us at blow the Mind at how stuff works dot com. Well more on this and thousands of other topics. Is it how stuff works dot com