Colossal: The Science of Human Height

Some of you may remember it from Mystery Science Theater three thousands, some of you may have just experienced it straight up, The Amazing Colossal Man. Now, Robert, I am sitting here looking at this looping gift that you put in our outline of a gigantic dude who seems to be filmed with like rear projection to make him look bigger than he is, throwing some sort of instrument that seems hand sized for him, but he's impaling a tiny,

tiny person with it. Oh yeah, this is a great scene because he's the character is is Glenn Manning, Lieutendant Colonel Glenn Manning. There's an atomic blast, he ends up growing uncontrollably. He loses all his hair and his clothes except for you know, alloying the loth that I assume is made out of sale made out of sale cloth or something. And there's a scene where they they're trying to arrest his growth by jabbing him with this giant

hypodermic needle. Of course looks like a giant hypodermic needle. Um. So they come in, they jab him, and then he picks the thing up, looks at it with anger, and then just throws it down like a javelin and impales it. Dude. It's a classic scene. So this was nine seven, and this was this was part of the era of filmmaking in America where it was just giant everything all the time.

Giant bugs, giant you know, leeches, giant rats, giant what else, giant giant spiders of course, any of those grasshoppers praying Mann. This is I mean, yeah, you name it. If it looked good or if it just looked passable and giant form, somebody was blowing that thing up. I think they'd figured out how to do rear projection technology that looked okay in film, uh, and so that they were like, oh god, we can make anything look you know, hugely out of proportion.

Let's just exploit this to the max for fifteen years and then throw it up on a drive in the kids will come and see it. Yeah, And of course the plot was always atomic radiation, right as it was in this case. So in The Amazing Colossal Man, the guy you said he gets uh irradiated by nuclear blast. I think he actually he's like he's they're observing the blast from the safety of a trench, but he gets up out of the trench to rescue somebody or something

that it's just you know, it's an heroic act. But bam, he gets blasted and it's a great scene of just standing there at the with the radiation washing over him and yeah, and he's reborn as this colossal being uh and it begins messing with his mind too. Yeah. So it's sort of similar to Beast of Yucca Flats. Same thing happens to Tour Johnson, and that he gets hit with an atomic blast and instead of vapor I sing

him burning him up. It just kind of makes him look crazy, makes him look a little bit bigger, and he has some oat meal on his face. Yeah. But then but the thing is, I mean, I don't want to undersell Tour as an actor, but Glenn Langan, who plays Lieutenant Colonel Glenn Manning in the in the film here like he brings. He brings a certain amount of at times hammy but still legitimate humanity to this character where you end up feeling for him like he's meeting

his his wife. Uh you know, he's he still has his humanity about him. He's even as the condition begins to go through his head. So you think this is actually a pretty good B movie, right, Yeah, I mean, going into it knowing what to expect out of a B movie. I think this is a great movement B movie. I think this is just a fabulous example of a particularly of a bomb B movies directed by Oh yes, the great Burt Eye Gordon bert I Gordon. So he's actually still alive and yeah, I was looking him up

and yeah he was born in two. He's still kicking at ninety two as of this recording, and IMDb claims that he directed a film in Okay. So Burt Iye Gordon. You you might have noticed his initials are b I G This Uh this. He didn't, as far as I know, he didn't change his name to be like this. It's just a happy coincidence that Bert Eye Gordon was known as Mr Big, Mr b I g because he loved to make movies about things that grow bigger than they

usually can. Uh. So. Other movies of Burt Eye Gordon's include War of the Colossal Beast that's the follow up, and then there's The Spider or Earth Versus the Spider, that has a larger than normal spider and it's not just like a suitcase size spider, it's like a giant spider. Like, I mean, you gotta go go big with your giant spider. Like she lops size pretty much. And then there is

Village of the Giants. There's King Dinosaur, which has a fun Mystery Science Theater episode in which astronauts travel to a planet full of giant reptiles and then they sort of flirt and romance each other. And then there's a lizard that is supposed to be a t rex I think, and then the astronauts nuke the planet to wipe out

indigenous life and make it safe for human colonization. Uh. And then of course there's also the Beginning of the End, another Mystery Science Theater episode, but that movie has a Midwestern town threatened by giant grasshoppers again, atomic radiation. Yeah, but since we're talking about human height primarily today, back

to the Amazing Colossal Man. Yeah, so nobody's gonna gonna bring up The Amazing Colossal Man is like a perfect example of science, but it does at least flirt with some of these ideas because you have this this guy. He's gigantic, he's powerful, and yet he seems to be

in a fair amount of just constant misery. Um, it's been a little while since to actually have seen it, but I I seem to recall that not only there there's there's elements of it affecting his mind, but but perhaps just being that big is at least a little bit painful as well. Um, and the mind thing is interesting. I have a feeling in the in the in the film, it's more about like radiation or something affecting his mind,

making him a little crazy, a little hostile. But I can't help but wonder it has something to do with the blood flow to his head. Oh yeah, like you're just trying to scale up the human body that things aren't necessarily gonna work right. Yeah, Because as we'll discussed, that's a major issue when you start thinking about gigantic human bodies or gigantic bodies of any kind. Um. For after after all, look at the draff right tallest vertebrate

on Earth. Uh And and it has to uh, you know, sort of quite a bit of energy to pump blood up to its brain. It has like an amazing amount of hypertension. I mean, the same kind of hypertension that would cause vascular damage to a human being and eventually perhaps lead to uh, internal injury and death. Is just normal for a draft because it's got to get all the blood up the neck to the brain and then

when it lowers its head to drink gravity. You can't have gravity then like sending all this blood to the head and what may in the draft's head explode. Nobody wants that, And that's why the giraffes have this system known as the rete mirabel and that's Latin for wonderful net uh. And it's just this net of arteries and veins that diverts some of the blood flow, equalizing the

giraffe blood pressure when the animal lowers its head. That's beautiful. Yeah, it's like a natural release valve to keep you from living in a world full of exploding giraffes. But it's an example how to have a creature that big, you have to have additional engineering constraints thrown in there to

allow that creature to live on that scale. Yes, and though The Amazing Colossal Men didn't get into a lot of the details of the science of what it would take to scale up a human body, other other writers have sort of dealt with this, right, Um, yeah, you know, I have not read a lot of the you know, they guess as far as a literary trope, that the giant humanoid is not really explored all that much. But the late Heart writer Michael Shay, he explored this a

little bit in his novel uh Niff. One of his niff the Lean Novel's Minds of the Bahina, which is a fine, fine work of dark fantasy that I highly recommend anyone out there looking for that sort of thing. But he also wove a lot of science into his work. And at one point in this book we encounter a human who has grown to colossal size. But he's so colossal that like he basically is just in constant pain.

He can't even sit up. He has to just crawl into the ocean and float away just because the body, the proportions of his body are not made to support that kind of mass. Now, wasn't there an old theory? I can't remember where I read this, but I remember hearing there was some old theory that these the largest of the dinosaurs, say like a brachiosaur or something like that, could only exist by by standing around in water all the time to partially support its weight with buoyancy. Yeah.

I've read some of those as well. In fact, we have an article on how stuff Works dot Com that I put together, like what's the largest land animal that ever lived? And he's a part some of these issues with the sauropods. But for to whatever extent that was ever proposed as a theory, I don't think that is believed today, right. And the other co course important thing. You look at these most massive creatures, the most massive land creatures living today, uh, are definitely walking around on

four legs. The Saara pods walked around on four legs. So um, it's it's very difficult to imagine a bipedal creature of that size. But then again, we have examples like the Tarrannosaurus rex, a bipedal creature that is extremely large, and they're actually there are larger bipedal dinosaurs than the sarannosaurs rex. Yeah, not quite as big as the sauropods,

but certainly yeah. Okay, well, so we should look at the issue of height and size in humans because obviously you don't have to look any further than the science fiction films of the fifties to see this general obsession with the idea of things being bigger than normal humans

and other animals. But while we're captivated with height and size in that kind of simple brutal part of our brains, we also have this counter narrative running right where in our literature and folklore there's always this story of the smaller person defeating the larger person David and Goliath to Jack and the bean Stalk, which you know, the folklora says a variation on this very ancient story they called the Boy who Stole the Ogre's Treasure. There are a

lot of variations of the story. And then in the modern day we have, for example, Bruce Lee always beating the bigger guy. Right, have seen a film where Bruce Lee does not just beat everyone up. It's true to the point of boredom, where it's like, really, these villains don't have shot. They seem to know that the thing you want to see most is this little guy, this little Bruce Lee, just killing somebody who's much bigger than him by punching him to death. And how would we

fit Master Blaster into the scenario? Ad Max taking a Master Blaster who himself is a giant with a little person on his shoulder. That seems to subvert the trope, doesn't it. So anyway, we we've obviously got this obsession. We're we're very into the idea of size as a basic indicator about how we should judge other people. Uh, and that sort of makes sense. I mean, it doesn't make sense morally judging other people by their sides, but it sort of makes a biological sense why we would

have these instincts. And and height is a sort of basic biometric indicator. For example, it's useful for scientists to track because it can be objectively measured, though not always with perfect act accuracy, because you know your height varies a little bit from different parts of the day, and you know it's not going to be exactly the same every time you measure it. But it's correlated with other important facts like nutrition and health. Uh, and in humans,

height is, of course, on average, sexually dimorphic. We know this. Average male height is usually a few inches taller than average female height. One thing that I was really interested in was I was wondering if there's any population of humans on Earth where that's not the case, And I couldn't find evidence of it, but I wonder if there is one out there that would be kind of cool

to know. Would Yeah, it's just so so so far just talking about human height, as we've discussed, you have you have of the the the the inherent sexism in the in the situation right, men on average or taller and there and therefore we're putting this focus on on height being an indicator of power. Um. Certainly, increased height can conceivably be an advantage in various combat scenarios. Of course,

a lot of that depends. Most of that depends on the skill of the fighters involved, and of course just linguistically, right, even if you're in a profession where really the height of an individual has no role at all, you'll still hear people say like, oh, well he's a giant in the industry, or oh she's a she's a looming figure in her profession, or or you might hear someone put down to say, oh, well that that was very small of them to do that. Like what, what do all

those words even mean? You know, we're we're still populating as if it's Game of Thrones and we're surrounded by giants and dwarves and giant blooded people. Yeah, but even if you are not, say, applying to be a pro wrestler or something like that, there are jobs, such as, for example, being a salesperson where somebody might hire you based on height because they know that the the inherent

biases of the customers might favor somebody who's taller. So one of the big scientific questions about human height would obviously be what controls human height? It's a clear fact of nature that we see obvious, you know, metric differences in the height of different adult individuals. So where does

this difference come from? And I found according to a two thousand six explainer I found in Scientific American by molecular biologists Chow Kwing Lae and Gene Mayor of the U. S Department of Agriculture Human Nutrition Research Center on Aging at Tufts, twenty two percent of differences in human height are controlled by environmental factors, and sixty to eighty percent

are controlled by genetics. So scientists have arrived at these numbers through a number of different means, including things like twin studies, you know, studying people who Okay, so we have monozygotic twins here, they should have pretty much the same genes, but can we see any variations in height between them or between them and other siblings and sibling studies, Uh, depending on what what environmental factors they're getting, such as nutrition,

especially nutrition and early childhood, early childhood health, access to healthcare, and things like that. And from this that they've discovered that the rate of influence of genes and environmental factors is variable, but it's variable around these basic ranges. But one thing that is true is that on average, humans today are significantly taller than they were a few hundred years ago. Have you ever noticed this, like if you, I mean, it's clear if you just look at environments

and appliances designed for people a long time ago. There are lower ceilings, lower doorways, smaller beds, smaller pieces of clothing such of armor was one I believe you mentioned earlier. Yeah, and so I though, that's an interesting one because I was looking into that and then I couldn't. I have this impression that I've seen suits of armor that appear kind of small compared to what I would think of

as a you know, a large warrior today. But I was looking for evidence of this online and I couldn't really find anything as saying that suits of armor are

smaller than we would expect them to be. So it made me wonder if suits of armor being made for the nobility and military classes of previous eras may actually have been larger than would have been required for the regular people, because, as we've discussed in previous episodes, we have these examples of noble individuals, ruling class individuals from hundreds and hundreds of years ago who still were tremendously

hot at tall even by today's standards. Oh yeah, I remember Old krogan Man, Old krogan Man, the bog body. What was he like six four or six six? He was incredibly tall, um, And of course history is full of these stories. Sometimes, I mean a lot of times you have to take him with a grain of salt, right, because there's a ruler and he was really tall. Do

I believe you, was he really really taller? He was he just he's just always standing on something or is this just you know, the myth and the legend of the man like one that always comes to my mind. And this is I think in large part because my my dad would tell me stories like this is a kid but um uh in ten sixty six, the events of ten sixty six Battle Hastings and all that. You've got stories of ten sixty six when you were a kid. Yeah, my dad would tell me about all that. That's pretty cool.

Of course, you had, you know, three different forces vying for control. There. You had Harold Godwinson, uh, king of England, who had William the Conqueror coming up from from the continent. And then of course you had Harold Hadrada, the King of Norway, and he was according to many accounts here, he was taller than most men. And Harold Godwinson makes equip that he is going to uh, he's going to offer him something, and he's gonna offer him six feet

of English soil or perhaps more. Sometimes it is say perhaps seven feet of English soil, since he's taller than most men. Um. The idea that he's going to you know, gift him the grave here but but yeah, here, here's a giant. Uh in history to what extend was an actual giant? I'm not sure, but but certainly we have tales like this of of and in some cases skeletal

evidence of tall noble individuals. And yet we have evidence that the average person of of a hundred and fifty years ago or earlier maybe you know, even going back longer than that, was just not as tall as the average person from the same ethnic groups and societies are today. And so why are people taller today? You know? One of the obvious questions is has height been selected for as a gene? Has there been evolution? Are we evolving taller? And I would postulate we can get into why in

a moment. I don't think that seems to be the cause. It doesn't look like it. I think scientists think that the change in human height is more due to environmental factors that I was talking about earlier, rather than major changes in the genetic factors controlling height. And this would make sense given what we know about improved access to

healthcare and nutrition around the world. Right, Yeah, A lot of the a lot of material that I was looking at for this was definitely focusing in on England and looking at industrial heights, you know, the industrial age heights and how they differed between the classes. So over the last a hundred and fifty years, um, we have seen the average height of people and in an industrialized nations

increase approximately ten centimeters or about four inches. Okay, that's nothing to sniff at, no, no, Now, it's a lot of people would would pay dearly for an extra ten centimeters. It's true. Uh, certainly, you know, glued on the bottom of their shoes. But anyway, it's inner of saying that this should occur, right because you think that evolution would be selecting for shorter heights, because based on previous studies, we know that you find taller heights and fewer offspring

among wealthy industrial British families of the time. Um, but also you find shorter offspring among the poor, and the poor are having more offspring. So wouldn't it mean that the short poor are going to inherit the earth because they're just gonna outnumber and outbreed the tall rich people. Huh. But it doesn't seem to play out that way. And most geneticists you have, believe that it's uh that what we've seen here, what's been the driving voice and force

and increased heights has been the improvement in shildhood nutrition. Uh, And that then that has been the most important factor in allowing humans to increase so dramatically in size. So there are a few different facts that kind of support this. So height increases only begin to manifest somewhere around the middle of the nineteenth century, and we do see dips in times in places of World war related famine, so

we can see that. Put it out. So here's here's an area that we saw a significant decrease in nutritional um quality, and therefore heights went down as well. The next generation you mean this order, and then the trend toward increasing height is actually largely leveled off, suggesting that there is an upper limit to height beyond which our genes are just not equipped to take us, regardless of

the environmental improvement. Okay, So you're saying like, if we get improved improved diet and access to healthcare as children, we're sort of trending further toward the upper range of natural human height. We're not extending what the range is. Yeah, there's no there's no quantity of carrots or no quantities of multi vitamins, they're gonna get you beyond what is essentially like the normal threshold for what we are as

a species. Right. Um, you know, in the same way there's not there's not a multi vitamin you can take that's gonna make you grow an extra arm um. And also we house it's one of those atomic radiation multi vitamins from the fifties and uh, and this kind of goes back to some of the data that has to do with famine. But conditions of poor nutrition are well correlated to smaller stature. So we've seen that born out time and time again. So that's not like a tenuous

hypothesis of modern science. We pretty much know now that if you're a kid and you don't get good nutrition, you won't be as tall exactly. So you know, the the answer there, why why are people taller today? It's

it's as exciting and unexciting as all of that. So yeah, to answer the question why are people taller than debt today than they were in the past, While it basically comes down to nutrition, well that's interesting, but then again it it makes me wonder how size does vary when it comes to genetic change over time because like you obviously do see size changes in the average size of a population of animals over time. UH, the norm does go up and down. So what happens there? What when

that happens? How does it happen? Well, one of the more interesting UH scenarios that occurs it has to do with the the island rule also known as Foster's rule, named for J. Bristol Foster in nineteen sixty four. UH. And this is this has to do with what happens when you take uh, you know, an existing organism and landed on an island somewhere. UM. So generally speaking, when one species arrives on an island, it can change forms

in ways. They don't necessarily generate a new species. So body size conforms to what we call the island rule. And it holds true for various vertebrates. So large specimens they become small, small species become large. And one of the more extreme examples of this is the the dwarf is um of megafauna. During the ice age. We saw dwarf elephants in ice age sicily and the small wooly

mammoths of Wrangle Island in Siberia. So how big were they? Well, I mean you couldn't fit them in your in your pocket, but noticeably smaller, like I would say, small enough to be cute based on the uh, the the average size of the normal organism. So the basic idea just here is that smaller creatures get larger when predation pressure is relaxed due to the absence of some mainland predators, and larger creatures become smaller when food resources are limited due

to land constraints. That's interesting. So the thing about smaller creatures becoming larger in the absence of predators, that points out one natural advantage to being smaller, which is that it's you know, you're you are not as delicious and nutritious of a treat, and it's easier for you to hide. So there there are plenty of selection pressures that would favor being not as large as one could be, uh not having the maximum size allowed by your body plan.

And I think that's something that's going to be interesting to keep in mind, especially for a thing I want to talk about later on. So I know what everyone's wanting. How does the island rule affect humans? Well, most of the time you don't see humans thrown into these scenarios, and certainly some people may be thinking, oh, well, pigmies right, um. But in those situations there seem to be a lot more Um. There are a lot more factors at play there,

including nutrition. So it's difficult to just apply the straight simplistic island rule to the scenario. But some have theorized that Homo floresi incests also known as flores Man or you know, hobbit man. You can probably a popular press, popular press. Yeah, So some have theorized that this is an example of of island island rule, island dwarfism at play with a humanoid creature. Uh. This was this particular specim was discovered in two thousand three at Langbau on

the island of Flores in Indonesia. And it's from numbers vary on this. I've seen the number drift in both directions as additional research has been conducted, but it seems like fifty thousand years ago is a general timeline we can stick to. Um. Uh that And there's a two thousand seven paper that came out title Primates follow the

Island Rule. Implications for interpreting Homo Floresien says by Lyndelle Broham and Marcel Cardillo, and they argued that that that that primates do follow the rule, and they used a comparative database of thirty nine independently derived island endemic primate species and subspecies to demonstrate that primates do conform to the island rules. Small bodied primates tend to get larger

on islands, and large bodied primates get smaller. Furthermore, large species, they argued, to undergo a proportionally greater reduction in the size on islands. But again that being said, human height especially as far more complex than this. Uh. Anytime you take you know, the the human organism, you start laying over all these various cultural concerns, when you start throwing in war and UH and and are more complex relationships

with nutrition. Um, it's it's very difficul well to just apply to rule to humans and in a fast and slick way. Another thing would be time scales. I mean, I think that within the time scales we'd be working with observing human history, there is not nearly as much time for for significant genetic evolutionary changes to accumulate like this. So you might you might have for example, sexual selection among humans or something like that, uh, tending people toward

you know, a certain end of the natural spectrum. But the time factor is going to cause significant problems for seeing a large, very noticeable changes in the human genome over you know, the short period of history we have access to. YEA. Indeed, all right, we're gonna take a quick break and when we come back, we're gonna jump right back into this topic. And hey, we're gonna talk about phantasm a little bit. Hey, everybody, you know, in this day and age, you've got to have a website.

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listeners out there? Um about the details in this cinematic masterpiece, Well, Phantasm is a horror movie. Don Coscarelli. Is that the guy who directed it? That's the man? Yeah? Okay, So the main characters in the oh god, could I even explain what the plot is? I don't know what the plot is. That's kind of the beauty out it right. Essentially, the main characters get chased around by this guy known

as the Tall Man. Who is a grim, dour funeral director, who who shows his teeth and he squints his eyes, and he's got lanky, gross hair. And this guy runs around a cemetery stealing corpses for strange purposes we can get to in a moment. And he kills people with a flying silver ball that jams itself into your head and then drills you with some sort of extremely produce just blood funnel that just pumps all the blood out of your head out a jet in the back. Anyway,

that guy was played by Angus scrim And. Uh, he's the actor who played the Tall Man. He was only about six four in real life, or so I read, but they used a bunch of movie tricks to make him seem taller. I think they gave him tall shoes, and they put him in a tight suit and stuff like that. Shot him at the right angles, maybe, yeah, exactly. But what is the tall Man when we find out what he's doing spoiler for this nineteen nine movie, when we find out his whole plot, what is it that

the Tall Man is going about doing with these stolen corpses? Well, he has a whole industry um and I forget how many of these details are presented in the first film, and how many come out in the subsequent films, But essentially he seems to be from another planet or another dimension, and he is taking the corpses, crunching them down into little undead dwarfs that presumably are being sent through this

stargate to serve as slave labor on another in it. Uh. And the idea here, I guess is that this other planet has is a is a larger world. There's a greater gravity, and therefore you need crunched down bodies to serve as the labor. Uh. He's also I think, using brains from the corps is to make the flying silver balls of Death. And of course that this this shines potential new light on his height. Okay, so he's crunching

down creatures to go to this other world. He's tall on ours, So does that mean is he is he shorter on another world? Is he a normal size like here? So when Superman comes to the Solar System with the yellow Sun, he gets special abilities. When the tall Man comes to a planet with much lower gravity in this sort of relaxed atmosphere, he almost sort of unwinds or

uncoils and grows taller. Yeah, that would be a great scene for any remake they do where the tall man steps out of the little stargate here and then you just his spine elongates like by like a foot or so. Just god, well, that's funny because it actually is a fact that human beings grow taller in lower micro gravity environments. Not that much taller. I don't think you know, a normal high, average height adult male would reach the size of Anger Scrim or even uh the size of Anger

Scrim and all of his tall man Kutraman. But it definitely is true that astronauts, for example, get taller while they're in the International Space Station. That's right. Uh, And NASA is known about this for a while. Uh. You going a trip into into orbit, and you can add up to three in height while you're up there. So if you're six ft tall, that's that's two inches you know, nothing to sneeze that. And that's because when the spine is free from the constraints of gravity, the vertebrae can

expand and relax. Now, once you get back on Earth, everything sinks back down to normal, but for a little bit you gain, you know, maybe a couple of inches I read actually that once you come back to Earth, you you return to normal height extremely rapid. It takes like less than two days. Uh. So when astronaut Scott Kelly returned from three hundred and forty days in space, that's a long time he was on the I S S. Uh. Scott Kelly came back earlier this year in twenty sixteen.

He'd grown about one point five inches while he was in the I S S. And when he returned his his normal height was restored within about twenty eight hours. And of course this would mean the same the same thing would hold true for low gravity worlds. Take Mars for instance, which has just one third of Earth's gravity. Oh yeah, yeah, so that would conceivably be a factor there if you were to visit it for extended length of time, and certainly if you're talking about long term

human habitats. Uh. Mars settlement proponent Robert Zubrin, who actually interviewed a few years back, if very very passionate dude about Mars colonization like he is, he is of the mindset, we should, we should be doing it yesterday. Uh. And here all the reasons we should and we can. Uh. Certainly, I recommend checking out any interviews with the man who's very Did he try to sign you up for the Mars death trip? No, No, that he was. He was

very passionate, because I think it was. There was an article that I did for Discovery News asking the question, you know, is it morally cool to terra form another world? And there were some that are saying, well, no, you you know you don't. We don't want to just go will annaling with it with the terraforming. You want to be respectful, you want don't want to disrupt the evidence of past life or certainly get in the way of any present life that might be there or future life.

But Zuber and he presented the opposite to argument that we should definitely be there. We should go there. It's a dead world, let's do it. I've actually read a lot about that. I think that's a very interesting debate, like what what should be our ethical obligations when dealing with other planets? Do we have the right to make them earth too? If we have that ability? Yeah, I mean we could do a whole episode of essentially on the prime directive, right, yeah, um, but how does the

prime directive apply to potentially dead world? Yeah, and yet and who are we to label a world dead, you know, because we have just have this one idea of what life is, right. Yeah, So anyway, Zubran has has spoken a great deal about Mars colonization issues, and one of the things that has come up is he's theorized that children born on low gravity worlds like Mars would have

a few inches on everyone else. But you'd have problems adjusting to high gravity worlds like Earth if you ever try to go in a pilgrimage here, and indeed you might not be able to return home at all, or there might be problems inherently, like even with the low gravity world. I mean, we've never seen what a micro gravity or low gravity environment does to a human body

over a really long term. Like the longest we've ever seen is what happens when you stay in a space station for you know, a year or whatever amount of time. The longest space station stay is now. I think Kelly was up there, if he's not the longest one of them. But anyway, astronauts report back pain. I don't know if you've read about this, but you know, according to materials provided by the I S S Program Science Office, Lower back pain is sixty eight percent more prevalent in space

than on Earth. And is this caused by the lack of the intervertebral discompression due to gravity. It's the same thing that makes you taller, the same thing that makes you taller. Actually, when you're lying down horizontally as you sleep at night. In the morning you get up your taller than you were when you went to bed. Uh. Does being separated from that that downward pull of Earth's gravity. I mean, obviously we didn't evolve to be like that for long, long periods of time, So what does that

do to you? It it might have some less than positive effects. Yeah, And certainly every human child ever born has been born on Earth. No one's ever been born in space, so we have no idea what human development might be like you a lower uh, lower gravity scenario. So, with all of those concerns in place, and the idea that being raised in a microgravity environment might really mess you up in all kinds of ways, it is possible, Bowle, that growing up in low gravity or microgravity might make

you taller. Yeah. Maybe so, so if nothing else you could you could you could cling to that reassuring fact because as we've touched on already. There's a lot of there's a lot of weird human hang ups when it comes to height. And there's an entire psychology to human height. Oh man. There there are a bunch of studies looking into this. Uh and and it kind of makes sense why there would be a strong psychology of height. You know,

height is a primal survival signifier, right. It advertises physical strength, reach, health, and good nutrition. And so for this reason, I think it's not surprising that humans have some natural tendencies when it comes to our psychological relationship with human height. I

think there's uh there. For example, is this pervasive notion that taller people have more social and economic success, that they're more persuasive, more impressive, that they you know, they just get they're just go getters and the all good things come to them. In fact, I remember I had a teacher in high school who who told us one time.

I don't know what his source was for this, Maybe it was just his own wisdom, he was making it up, but I remember he told us that that if you want to if you want to persuade people or to be a good leader, the most important thing is height, and the second most important thing is being funny. I think the emphasis being on how well, if you're not tall, you better darn well be pretty funny. Well, I mean that makes sense. Look at Jeff Goldbluin, seems like a

funny guy, very tall guy. I'd followed him anywhere. Yeah, he could. He could tell us all to jump into a volcano, and I'd be pretty sure he had a good reason. But anyway, is there anything true to this or is it just another unsubstantiated folk myth based on our biases. So there was one huge landmark, highly cited paper from two thousand four about this in the Journal of Applied Psychology by Timothy A. Judge and Daniel M. Cable.

And they did this deep investigation on the you know what could be known at the time about the correlation between height and success, and they certainly did find a strong correlation between the height of a human and for example,

career success. And so it was summarized by the American Psychological Association as with this startling fact, for someone who is six feet tall, they earn on average a hundred and sixty six thousand dollars more during a thirty year career than somebody who is five feet and five inches tall, even when controlling for other factors that could contribute to that, like gender, age, and wait, they found that taller men and taller women are both more successful in their careers,

but that the correlation is stronger for taller men. And they're fascinating questions that come along with research like this because all, you know, what they can establish is the correlation. They can't necessarily show exactly why this is true. Uh So you could have lots of hypothesis hypotheses, Like some people would say, is it true that taller people are

smarter and that's why they make more money? And that doesn't appear to be the case though that I think there have been some studies attempting to link height with intelligence that they didn't find that that that was the

primary explanation. Uh So, could it be that taller people are just respected more by others and you know, the boss looks at a tall person and says, you look like you deserve a raise, or could it be that the way tall people are treated by others leads to more self actualizing behaviors and you know, makes people more confident go in and ask for the raise more often there.

There are a lot of ways you could try to explain things like this, like maybe in a cubical environment, when they stand up, it's easier to see their heads, so the boss that sees them more often, or perhaps their brain is closer to Heaven just by virtue of height. Yeah, how does this all make you feel today, Robert? You're being one of the taller people in our office? Um?

You know I do. I kind of like second guess the role of height a lot in my daily life, you know, like I like I find myself second guessing, um, you know, things that go right, or I'm like, oh did this didn't did my height play into this? And then I started thinking of studies like this, and it's like, is this just all a virtue of me being a little bit tall? Um? And then and then of course

I curse my height when I bump into things. And then I then I wonder like, well do I I actually end up looking like like an ungainly tall person as I'm walking around the office. And therefore I'm like I don't fit in as well, like I'm more of a like a freak. You know, Yeah, you really are? Well?

Thank you? Oh no, I mean being tall might be another one of those things where we discovered that there are just natural biases at play, for example, like the natural advantages or privileges some people might enjoy for being male in the workplace. You know, sometimes you're just gonna

be treated differently and you might benefit from that. Yeah, And I guess like you just end up it's like second guessing, like how everyone around you is interpreting things, Like I've often found it weird, like I've always been taller than my bosses. And obviously being tall has nothing to do with being or being short in height has nothing to do with your ability to lead in a

workplace or being effective boss. But for some reason, there's always this like weird, Like I don't know if it's like a grade school or lizard brain voice in the back of my head. It's always like like, is this weird that my boss is shorter than me? My boss gonna hold it against me because I'm taller, like as if as if like one if one gave man is going to rise against the others, like he must be

punished because he was taller than me. But still like you can't help, but but here those just nutty paranoid voices from time to time. That's great, Robert. I hope you will always share what these voices are telling you with me like I had. It probably has to be the same for people with great beards, um um. And you have pretty great beard yourself. I don't know about that. I do not grow that that great of a beard.

So if I had, if I were to have a great beard, and I was to have a boss with a lesser beard like that would feel a little weird, like I would. I don't want my my beard to get me in trouble because of its boldness. Uh. Yeah, Well the beard and the and the height thing again this comes into I wonder if this is uh, this is natural sexism in our mindset also playing into because of the sexual dimorphism of height, the fact that on

average men or taller. I wonder if sexism also plays a role, Like if height in some way manifests in our minds as some attribute of manliness, And because we have this unconscious bias favoring manliness, is that another reason that we pay tribute to the tallest? Yeah, the tallest and an accidental invader Zim reference there where the the leaders of Zim's race alien invader race um. They are

called referred to as the tallest. They are the tallest of their species, though clearly they've been augmented with with outfits and machinery to make them appear. Oh they're cheating. Oh yeah, they're cheating, and they're lifting. Yeah, they're definitely lifting. Uh, but yeah, that's the tallest. Well, this brings us to the question I think that maybe we could conclude with,

which is how tall exactly could humans grow? We've talked about how humans have gotten, on average a little bit taller over time, though this doesn't seem to be from you know, serious genetic mutation or revolution, but more through nutrition and access to healthcare. But imagine we were, for example, able to genetically alter the human race. You know, we're going to go in and tinker with our genes and try to create the world's tallest human. Could we make

a human that was like Glenn Manning. Could we make a fifty foot human? Could we make you know, Attack of the fifty Foot Woman. That's another b movie about the giant human. Could we make a hundred foot tall human? Or even just being more modest, could we make up fifteen foot tall human? Are are any of these things

really possible or would we hit insurmountable problems. Well, I guess it's easier to shoot down the more extremes first, yeah, and then and then scale back down, because yeah, when you're talking about Glenn Manning, when you're talking about Godzilla, King Kong, any of the or any of these various giant creature movies we've discussed already, Um, there are engineering limits to the body size. Yeah, and I would totally

agree with that. I think that Unfortunately, for the people who want to, you know, change their their genetic code to be twenty ft tall, it's just not gonna happen. That's just not the way humans are gonna work. And we'll try to explain why. So. The tallest man who ever lived, as far as we know, was a guy, an American guy named Robert Wadlow, who at the time of his death was eight feet and eleven point one inches tall, as almost nine ft tall two hundred and

seventy two centimeters. That is so tall. If you see pictures of this guy, you're probably not imagining him tall enough. Uh, look up a picture, You've got to see it. Wadlow died at the age of twenty two though, unfortunately, and he had serious health issues that seemed to be associated with size. This might come as a surprise because our natural intuitions, as I've said earlier, sort of, I think

we group height as a health indicator. We think of somebody who's very tall as somebody who's strong and healthy, and you know that they like their body is doing good. But the issue with Wadlow was that he he encountered multiple problems because of his size. His He suffered from a condition where his body produced excess growth hormone, and it was continuing to produce excess growth hormone as he kept growing, and this just kept making him larger and larger. Yes,

I believe the condition here is the acronola. Yeah, yeah, I think so. But anyway, so he had problems and for example, what led to his death was that Wadlow an infected blister on his foot from braces that he had to wear on his legs because of his size. And one of the problems that he would have is that he had very little sensation or feeling in his lower limbs. Again probably because of his size. The body is just not built to be that big and in

many cases the supporting organ structures can't accommodate it. Uh, And so he got an infected blister that he wasn't really aware of because he had this lack of sensation in his lower limbs. And he died at the age of twenty two. And also I've read in several places that there was no sign when he died at the age of twenty two that his growth had stopped. He seemed to be still growing. So that's a sad story, but it doesn't introduce the idea that there are design

constraints essentially on the human form. Yeah, I mean he You can also look at at other cases of acromegalay, at cases of gigantis and acromegalay in particular layer which is again this has caused when the anterior pituitary gland produces um excess growth hormone. UH. This can result in a number of different symptoms such as severe headache, arthritis, and carpal tunnel syndrome in a large heart, liver fibrosis, bile duct hyperplasia, hypertension, um diabetes, heart failure, kidney failure,

as well as cancer and loss of vision. Because again it's just the design constraints. I often think about this in terms of like a business scenario. So say you have a food truck, right and you want to evolve that. You want to grow that into a you know, a brick and mortar restaurant, and for there, you want to grow that into a restaurant chain, and from there you want to grow it into a restaurant franchise. Each of those is not just a larger version of the preceding form.

Each of those is a a more complex system um and and if you attempted to do to to achieve the goals of one with the with the smaller form, there would be massive problems. Yeah. I think that's a really good example. And the one I was actually going to use was the comparison of just regular buildings, like building a house versus building a skyscraper is a completely different type of project. It's not just a question of

scaling up the house. You can't use the same materials and techniques that you would use in building a house to build a skyscraper because it's not gonna work. I've I've had to research skyscrapers for the other podcasts that I do here on uh how Stuff Works, on forward Thinking, where we talked about the future of skyscrapers, and one of the things that impressed itself upon me from that is that skyscrapers aren't static. They're not like a building.

They're really more like a giant machine because you have to keep in mind all of these incredibly voluminous uh amounts of things that are coming in and out, all of the heating and air, all of the plumbing, plumbing, you gotta have pumps that get stuff up to the top of the skyscraper. Just the transportation of people exactly. Yeah, elevators managing elevators, Like so, if you're in a hundred story building, can you just have normal elevators that go

up and down like normal elevators? How long are you going to be on the elevator if you're trying to get up to an upper floor. Uh So, you know they've got to have design considerations like that, express elevators and different types of elevator lobbies and stuff like that. Yeah, I could remember correctly. This is like one of the major design problems with the highly conceptual um Illinois mile high skyscraper that Frank Lloyd right designed, because you know,

tremendous mile high in the sky. But then when you start breaking down how people are going to get to the upper floors, how many elevators you're going to need, that's when you run into the real engineering problems that prevents such a structure from coming to reliship. What do you do if there's a fire drill? Yeah, I mean it's hard. It's bad enough when you just have a what you know, fifteen or those stories, yeah, much less

a mile of skyscrape are up there. Yeah, So we should actually get into some of the examples of why it doesn't make sense to just continue scaling up the human body from its normal size. Indeed, so there's a as an offer by the name of our McNeil Alexander, and he has a wonderful article titled engineering limits of the Body Size of land Animals. And this is actually available in a couple of different forms. I have it in a big book of scientific essays about like big

questions about life on Earth. But he uses the example of King Kong. King Cong is a great example. It's a giant gorilla and uh as as you know, as as most people are aware. Yeah, but I thought it was a giant human and a gorilla costume. No, no, it's it's it's a real gorilla now. But King Kong as a giant gorilla. If if he were to step off of the screen and exist in our real world,

he would collapse under his own weight. He would be one hundred and twenty five times the volume of a real ape loaded with one hundred and twenty five times the weight of a real gorilla, and his legs would just simply snap like kindling. So one way to look at this is to apply the spherical cow example. And what you've heard of us about you've heard about spherical cows, Okay, well,

spherical cows in general concern. It's sometimes for any time you take an engineering problem and you like simplify something like we're talking about a cow, so will just make it a sphere so as to more easily talk about it. And sometimes it's a criticism of sort of physics approaches to solving problems, but it actually works really well in this scenario. So assume the cow is a sphere, right, So as the sphere gets bigger, it's volume increases more

rapidly than its surface area. Double the radius of a sphere and the surface area increases four times, and the volume increases eight times. So double something size and keep its proportions the same. Its weight doesn't double or even quadruple, it increases by a factor of eight. This gets into situations why you would to to take a small creature and make it bigger. You would have to drastically change its proportions to support the weight. So you know, Keen Kong,

a giant human. The basic morphography of the creature would have to upgrade as well. Yeah, okay, so the strength of the molecules and the bonds that make up your

bones is not going to get proportionally stronger. It's gonna be You're dealing with the same molecules either way, and the same issue as you'd be dealing with the same energy constraints either way, right right, Like, So a proportionally voluminous creature like this would have proportionally great energy needs and ways of dissipating excess heat energy to right, Yeah, it would just have to eat more bananas. You'd have to take into account. It's hair, you'd have to take

into account, it's metabolism. So, as arm McNeil Alexander points out in his article, uh, a mammal one five times heavier than its original form, would need to metabolize forty times as fast, which means Coong would have to lose x has heat from his skin, which has only twenty five times the area of a real to eight skin due to proportions, and he has all that super thick fur five times as thick as a real guerrillas, which

is not going to help matters either. So not only would call collapse under his own weight, he then overheat and die right there on the pavement before he could ever climb the skyscraper. So then what's going on with these incredibly large animals that we do see, like, for example, I I'm excluding water dwelling animals because once you're living in water, that seems like that's a very different kind

of environment and different things are possible. But but these land dwelling animals, like the largest sauropods, big dinosaurs, what's going on with them? Well, I mean it's it's ultimately going to be more a matter of what's competitive in the struggle for existence, as as Alexander points out, because uh, I mean that's gonna be the deciding point. Can the can the market bear it? Can the can the market allow a restaurant this huge to exist. Um, you know,

it's it's similar to the giant aircraft. Right, there's certainly giant aircraft that can be built, but will they be built? Well, is there actually a reason to build it? And then if built, is there going to be a reason for it to remain a part of our aeronautic um you know Kingdom? Yeah? Yeah, yeah, yeah, I wonder And now I've not looked this up. It just occurred to me. I wonder if there's an upper limit on the mass

of a thing that we can make fly? Is there just an object so heavy that there's no way to make a vehicle this heavy fly? That's a good question. Yeah, what is the what is the heaviest possible air vehicle? This would be a fun one to explore, especially in light of you know, some of these Marvel films that have come out with the like the aerial aircraft carrier ships. You know, well, I mean I guess it would. It would depend on whatever is the maximum limit on the

the opposing forces that we can create. I'm assuming we're not using like gigantic balloons and stuff like that. Going with with with fat s flying airplane style, Yeah, balloons tend to be the best way to get them up there. Failing that magical anti gravity. Yeah, but I think it should be clear at this point that you can't just scale up the form. And uh and and you mentioned also one thing about insects, right, this this also applies

to other films of the nineteen fifties, right. You know, you've got the Giant Spider Invasion Earth versus the giant spider huge ants in them them as huge ants. They're big bugs everywhere. Yeah, I mean even things like I hesitate to drag those xenomorphant into all of this. But take say the Gartham from the Dark Crystal, you know, giant presumably exoskeletal creatures, or the giant crabs of of

of various beloved works of British horror um. These largely just don't work when you start blowing them up that big because they're exoskeletons. Would have to just get increasingly and eventually impossibly thick to support them, because the exo skeleton is not just armor, it is a skeleton. It is a supportive structure. Yeah. And if you'll allow me to go on a quick tangent from human height here I do. I looked into this a little bit because

I thought this was interesting. I was wondering, why don't giant spiders exists. I'm not sure exactly what the limitations on the upper on the upper end of insects and spiders are. Could we have bert I Gordon's giant grasshoppers and stuff like that. And my guess was that it actually might have something to do with their open circulatory system, being you know, spiders and insects don't have full body blood vessels like we do that maintain blood pressure and

keep everything going to the right place. They've got open circulatory systems, meaning they might have some main artery just like one big one or something like that, and then through a lot of the body cavity the body fluids in the blood or they don't have blood exactly like ours, but their oxygen distributing juices are just kind of loose, they go wherever. It seems like that system works less and less well the bigger you get, the more you've

got gravity pulling down on those body fluids. But anyway, I decided to look into this, and what do you know, I could not find any scholarly articles on why insects and spiders can't grow to the size of tour buses. Uh. This seems like a massive oversight. Somebody needs to start a peer reviewed journal for this. But I did find some pop science articles that at least interviewed some insect

physiology experts to get their informed opinions. And so there was a twenty twelve piece on Science World that spoke to a few experts about why we don't encounter giant spiders. Uh. The spider systematist Wayne Madison of the University of British Columbia just suggested the general issue of scaling like we've been talking about here. A guy named Rod Crawford at the Burke Museum in Seattle suggested that the main problem

could be respiration. Actually, because the spider has to oxygenate its tissues and purge carbon dioxide through a system based on breathing tubes called trachea and book lungs and also copper based blood, and its respiratory system just would not scale up because it couldn't get enough oxygen to all

the parts of its body fast enough. And the author points out that this could be the reason we see fossil evidence of much larger insects like you know, those huge hawk sized dragonflies living at a time when Earth's atmosphere was more oxygen rich than it was today. So there used to be a higher composition of oxygen in the atmosphere, and so these less efficient uh, you know, bug breathing systems could could get more oxygen to more

tissues that way, allowing a bigger bug. There was also a twenty twelve article in Live Science that interviewed an insect physiologist named John Harrison at Arizona State, and he had a couple of hypotheses. He mentioned the exoskeleton limitation problem that we mentioned, but he also notes that one city has shown that exoskeletons don't necessarily become thicker as insects get larger, so this may not actually be the constraint. Uh. He also he points to the open circulatory system that

I mentioned as a potential problem. Uh. He also mentions the respiration issue and uh, and these these ancient dragonflies that existed three hundred million years ago that could have these giant wingspans, huge bodies run around preying on other on other animals. But finally he's he suggests something that's interesting to me, which is that it's uh, not just a physical architectural constraint, but an evolutionary constraint. This came up earlier when we were talking about pressures on the

island rule. You know, why might why might uh? Sometimes animals want to be smaller and he he mentions that bigger insects prove more enticing meals to insect eating predators like birds and mammals, so they've got more nutrition in them. They're they're just better to eat, and it's harder for them to hide and go out and noticed. So there could simply be a strong selection pressure against larger insects and spiders based on the rate of predation. There's just

so many predators out there air. It just doesn't it doesn't pay, evolutionarily speaking, to get bigger. And so finally, I want to conclude with the idea of I wonder if there's anything like that that applies to human beings other than just the limits on what's architecturally possible with our body plans as they are. Are there any selection pressures that would keep humans smaller? I mean, it can't tend to think of any, but that doesn't mean they're

not there. Maybe I just don't have enough imagination on this, like scenarios in which a larger person would would not have a like a breathing advantage exactly. Well, I mean, we're at the top of the food chain and have been for so very long. It's hard to imagine predation playing in you could I mean, I guess you could maybe make a case for uh, sexual compatibility between males and females in some scenarios without you know, getting too

nitty gritty and the details. But I mean, I don't know that could conceivably be an issue if two creatures cannot physically engage with each other, um, you know, that could become that could that could apply at some pressure on the evolution of the form. Yeah, yeah, I mean I can't think of anything really, but I uh, but I wonder maybe you listeners out there have some ideas what what could be any possible evolutionary selection pressures favoring

a smaller human being? Mm hmm. You know, I'm instantly reminded, of course, of of just in terms of dimorphism here of a cuttlefish, various cuttlefish where you have both the large males and the smaller males, both vying to breed with the female, and the larger male breeds by just

sort of you know, fighting off competitors. Then the smaller male will use deception, will sneak in there, will pretend to be a female so as you get closer to the female, sometimes taking on the appearance of a male on one side of body while taking on the appearance of the female on the other side, and getting in there close enough and then breeding with the female while the big scary male is guarding it. So this being an example where you see both big and small bodies,

both large and small forms having reproductive advantages. So that's one possibility that's fascinating. I hope that doesn't so much apply to human being. I don't think it's It applies one to one to the complexities of human human love and human reproduction. But it's worth keeping in the back of your mind. Yeah, or anything else. I think that's it.

I mean, we covered everything from phantasm to the amazing colossal man, from giant spiders to giant guerrillas to people in space, so I feel like we, uh we we did it justice. In the meantime, check out stuff to about your mind dot com. That's We will find all the podcast episodes, videos links at our various social media accounts, blog post, you name it, it's all there. Hey, wherever you listen to us, whatever me you have to get this podcast. If they have a way to leave a review,

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