StarTalk Radio - The Physics of Superheroes

Episode Date: March 28, 2013

Faster than a speeding bullet? More powerful than a locomotive? James Kakalios, physics professor and author of "The Physics of Superheroes" discusses the science behind the amazing powers of our favorite caped crusaders. Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. Welcome back to StarTalk Radio. I'm Neil deGrasse Tyson, your personal astrophysicist. And this is one of my favorite subjects of all time. We're going to talk about the physics of superheroes patrolling the streets of gotham swinging on a spider's web leaping tall buildings in a single bound and i can't do that alone i need help and i combed the streets of gotham and i found eugene merman e Eugene. Hello. Welcome back to StarTalk, man.

It's great to be back. I couldn't do this segment without you. No, no. I knew you'd have something to say about every one of these things. I do. I have an opinion about all of it. I even brought a ring powered by willpower. Is that right?

Yeah, yeah. You know someone named Willpower? No. So, Eugene, do you have some favorite superheroes? One, all of them uh oh that's a cop-out answer come on now okay no i'll get specific geez green lantern i'm a big fan of green lantern he has a ring that is powered by willpower hence and he controls the universe just like any good person would what's with all the green there There's like Green Hornet and you know, what's with the green? I don't know. Yeah.

It was not of my design. Okay. So the Green Lantern, what else? Anybody else? Batman, because he's like Mr. T. He's like mean to criminals

but really nice to children. Except he can't, he's got a cape but he can't fly. I never quite understood that. He can't fly but he is also just really great at a lot of, I don't know but he is also just really great at a lot of...

I don't know. He's just a smart guy with a lot of gadgets. And it helps that he's a billionaire and can build whatever he wants. And very mad. He's super angry. Don't piss off a superhero. So we're going to explore all different features of superheroes. Some that they're born with.

Some that they're genetically engineered to have. Other features that are acquired by technology. There's no end to this subject. In fact, I don't see how we can fit it all into one show. I don't even know if that's possible. Maybe we won't stop. Maybe at the end of the hour, we will just keep recording. Somebody's going to cut us off. And so what we did to make the show happen is there's a colleague of mine, a physicist who is at the University of Minnesota. His name is James Kakalios. It's a very pretty name.

It is beautiful. And he's a physics professor at the University of Minnesota, and he's author of The Physics of Superheroes. Now, how could I not interview this guy for StarTalk Radio? And guess who published that book? Well, I could guess really accurately, or do you want me to ask? Because it's Gotham Publishing. Gotham Books.

It couldn't have been anybody else but Gotham Books. I don't know if they invented it just for that book or not. So let's just get started right with the first clip from my interview. We had met up in Los Angeles at a conference, and I snapped, pulled out my microphone and grabbed every minute I could of his time. One of his favorite superheroes is the Flash.

Oh. Flash goes really fast through the atmosphere, but that could be bad if you don't have, like, heat shields and things. Yeah, well, he breaks the speed force or something. So let's find out. From the point of view of teaching physics, the Flash, who can run at super speed, is a great character.

How fast does the Flash run? Well, in some cases, he's run faster than the speed of light. In one story, he found that as he was trying to run at the speed of light, he was going slower and he was becoming heavier. Oh, they're invoking some relativity there. Those who know Einstein's special theory of relativity know exactly why the Flash was getting heavier. An alien was shooting him with a gravity-increasing ray. But if you took it out of context, it was a beautiful illustration of Einstein's principle. What accounts for flash's speed? I don't remember.

Oh, he was struck by lightning and doused with chemicals at the same time. And rather than suffering any type of neurological damage, he obviously gave the ability to run at super speed. And rather than dying. Exactly, yes. The ability to run at super speed, the interesting thing when you look at it from a physics point of view, there's a host of other secondary powers that you need if you want to fully run at super speed.

For example, you need to be able to have super acceleration or super deceleration because otherwise you'll only be able to start running at, say, 32 feet per second per second, and it would take you a while to get up to... What you're saying is you can't accelerate faster than gravity allows you to. Correct, yes. Okay. Now, you also need to be able to overcome air resistance. Wouldn't some of them just burn up moving through the air that fast? Exactly right. In fact, in one issue of The Flash, he lost... He's still able to run air resistance. Wouldn't some of them just burn up moving through the air that fast? Exactly right. In fact, in one issue of The Flash, he lost, he's still able to run at super speed, but he lost his ability to ignore the air resistance.

And so his power was limited because if he ran too fast, that's exactly what happened. So that's one where whatever his version of the heat shields would be or his version of how he can part the air. Absolutely. That's right. Pushing the air out of the way. At least they thought about that problem. And as a kid reading this in the 60s, I was

actually embarrassed because I knew that meteorites burned up in the atmosphere and it never occurred to me that the flash should also be burning up. Now you know you have a geek on your hand when he's upset with himself for not judging flash correctly after having already known that

meteorites burn up in the atmosphere, Eugene. Yeah, it's true. So you know about it. But meteorites can't access the speed force, so there's the flaw there. Clearly, that's the problem. So, you know, Earth plows through anywhere between one and 300 tons of meteors a day. Really? Yeah, this is how much debris is just hanging around the solar system, left over.

And we just vacuum it up. That sounds like it's a lot of weight compared to a human being or a truck, but it's really small compared to Earth. So Earth just brushes this off. And some of them are big enough to make it all the way down and not completely burn up. If you find them, then we call that a meteorite. And so if you want to get your vocabulary straight. Straight. I do.

And so what happens is they're going 10 miles per second. That's really fast. And then they slow down coming into the atmosphere. That energy, kinetic energy, has to go somewhere. And you don't lose or gain energy for free. And in the case of the meteorite, in the case of the space shuttle, all that energy speed gets converted to heat. And in the space shuttle, it dissipates with the tiles. And the meteorite, it goes back into the meteor shooting through the atmosphere

and it burns up and you see it as a beautiful shooting star at night. Oh. Isn't that beautiful? That is really pretty. So if you like the, you said before the clip that you like the green lantern. But if you had your own superheroes, your own superpowers, what do you think you'd want? Well, I can't say. So clearly you haven think you'd want? Well, I can't say.

So clearly you haven't thought about this. Well, I can't say. I thought every guy has thought this through completely. Well, I mean, one, I'd love maybe just a cape. Maybe that'd be nice enough. But then part of me is like, I don't know, do I want to be able to have somebody shoot me and then the bullet bounces off? That sounds nice. But then I'd really rather fly, even though it's useless.

But how fun would it be to fly? But then I'd need to be resistant to cold and all this stuff. It just becomes exhausting. It's not that I haven't thought about it. It's that I get sleepy thinking about how many powers. Telekinesis. It'd be great. To move stuff at a distance.

Yeah, with your mind. It'd be mostly very convenient. Well, let's get back. In my interview, we talked about realistic superpowers versus unrealistic ones. So, cape realistic telekinesis. Well, cape can be real. It's whether or not it allows you to fly, which clearly it didn't for Batman and it did for Superman. Let's see where realism takes us.

Let's start there. Most realistic. Okay. I often say Batman because he doesn't have any powers. Of course, the number of times... And of course, he can't fly. That's correct. The number of times he's been knocked unconscious in his crime fighting career over 60 years, he should be permanently brain damaged at this point. So obviously, he has some sort of Homer Simpson extra thick padding or something. I would have thought that behaving that way from the beginning was evidence of brain damage. Yes, dressing up like Dracula and going out and

beating up muggers is not usually a sign of stability. Iron Man is actually a good example because there's only one miracle exemption from the laws of nature you have to accept, that he has a power supply that could run the suit. There are exoskeletons, there are jet packs. Okay, but that's just a power supply we haven't perfected yet. Well, in the movie, the 2008 movie Iron Man, he has a power supply. That's with Robert Downey Jr. Exactly. He has a power supply about the size of a hockey puck

that puts out the energy of about three nuclear power plants. So if we had something like that, superheroes would be the least of our trouble. That's a good point. Who's the most unrealistic superhero? Is it Elastic Man or something? Well, yeah, certainly characters who can stretch. There are characters who can change size. So you have to wonder where their missing mass either came from or went to. Well, they're not getting just less dense?

Well, that's an excellent point. And there's a beautiful illustration of this. But just to clarify, if you are one size and later on you're another size and you don't add any material to you you have to be less dense than you were before you inflated like in a balloon yes exactly exactly so it means you'll float better there was once a comic where the earth was attacked by a giant monster who every time you struck him with an energy beam got bigger and they discovered by noticing that his footprints were getting larger but not deeper that he was actually growing at constant mass but not constant density just as you say because if had he been getting heavier the footprint would sink further into the exactly so they found that the way to defeat him was to continually bombard him with

energy until he became so large that his density was less than that of the background of space. And she just floated away. Exactly right. That is brilliant. It was an old Fantastic Four comic back in the 80s. So there are examples like this throughout the history of comic books where if you just cherry pick, you can find correct applications of physics that you can use for instruction. And then once you've illustrated the physics principles,

you show how the same concepts apply in the real world. That's another clip from my interview with James Kakalios. He's a physics professor at the University of Minnesota, author of The Physics of Superheroes. That's awesome, Eugene. Yes. You know, just to figure out that you can take a creature and beam him, he'll get bigger, but not... Until he'll get lighter and float away.

And float away. Yeah. So you have to be, like, more clever than the creatures themselves. Yes. It's disappointing to know that you can't shapeshift. I was going to say it'd be great to shape... Or you can, but you'd have to remain the same size. Oh, yeah.

Which defeats, you know, becoming a dragon or something. You can be a dragon your size. You could be a different person. I guess you could look like other people. That's helpful. That's how they've done it. So, you know, they've got things like jetpacks. We've seen them from the early clips in the 19th.

I have one. Really? I mean. Is that how you got here? I mostly use it indoors. It's actually very dangerous. And you can get one. It costs like a hundred grand

and they seem really unstable to me you're gonna do a kickstarter for a jetpack and and if you if you troll youtube if you troll youtube videos first they all look like people are doing things it'll just kill you but among the categories of those that might kill you you've got people testing out jetpacks and you know this was the future we all imagined we'd be living today. Yes, we'd take our Zeppelin and then jump out of it in our jetpack, and then we'd be at work. Are you disappointed? I mean...

I don't know. I don't think I... I mean, I'd like to be able to fly, but I don't think I'd like to fly by setting myself on fire, or almost. So there's another side of this we can get to spend some more time on later. There's the mixture of technology and biology that goes on inside the body. Cyborgs, basically. And we can talk more about that later in the show.

But before then, I want to also get back to my interview where we talk about powers that might be kind of mystical. Not necessarily expressions of strength, but of magic, essentially. And in this clip, we talk about Wonder Woman and some of her mystical powers. Wonder Woman was an Amazon princess, which explained how strong she was. She had a lasso of truth that if she wrapped it around you, compelled you to speak truthfully. Interesting, fun fact, Wonder Woman was created by Charles Molson Martin, who was the co-inventor of the polygraph machine. Really? The polygraph, the lie detector? The co-inventor of the lie detector gave Wonder Woman a lasso of truth. She also had these

bracelets with which she would deflect bullets that were fired at her. And then we analyzed this from a material science point of view in the physics of superheroes. What are these bracelets made out of that can deflect bullets? And we can calculate the force that a bullet would have on the metal. In order to not deform the metal. Exactly. If it hits it. And cold rolled steel would probably be strong enough. Is that right? So Amazonian metal is apparently nothing fancier than very hard steel. What they could have had access to easily.

Of course, her wrists don't snap, so she's still excessively strong. But she's quick enough to aim her bracelet into the path of the bullet. Those reflexes, yes. That's exactly right. I'm glad that she's fighting for our rights in her satin tights. What's that? Eugene Merriman. You know, I wonder, so here we have Wonder Woman,

here we have Wonder Woman Here we have Wonder Woman Making you tell the truth By wrapping a lasso around you But of course If she was a guy She would have just Pummeled the person Well she can do both

She has both a strong And gentle touch Oh that's what it is That's how you make that happen Man So we're Coming up at the end Of our first segment

When we come back We have much more Of the physics of superheroes when we return. We're back. We're talking about the physics of superheroes with one of my favorite comedians and who's also my co-host, Eugene Merman. We've been listening to clips of an interview that I conducted with Professor of Physics James Kakalios, author of The Physics of Superheroes. He works out of the University of Minnesota. And in this segment, I'm going to bring in, because all of life is not just physics.

In fact, life is also- Name one other thing. I think every now and then you got to tip your hat to the biology that goes on within life. So we snared a bio- he was walking around the streets of New York a couple of days ago and we found him. Lee Silver, professor of molecular biology and public policy at Princeton University. And he's a specialist in genetics and its impact on human personality. And he just thought about how just genetics and technology, and actually he's formally trained in biophysics.

So, Lee, welcome to StarTalk Radio. It's good to be here, Neil. Yeah. Hi, Eugene. Hello. So you're here. You're going to just jump in whenever we say something either incredible or credible. Sounds great. Could you make a genetic potion that I could drink and become magic? Well, I think everyone wants a genetic potion that's going to

make them attractive to women. No, I don't want that. I want to be able to fly or jump to the second story. I don't even need to leap the whole building. That's a pretty modest request. Give me the powers to jump 20 feet in the air. Into a building. I don't even mind hitting it if I'm okay. Well, not at our weight.

That's the problem. Right. So what I like are those superheroes that they started out normal, and then something happened to them, and then they have some new biological power. And I think the most famous in recent times, based on the popularity of the movies, is the Spider-Man series. Spider-Man. And so I had to talk to my man about Spider-Man and find just what he says about him.

Because what a unique set of properties this guy has. And let's find out what he tells us. unique set of properties this guy has. And let's find out what he tells us. In the 2002 film Spider-Man, Sam Raimi decided that having Peter Parker make his own webs, technologically,

seemed a bit far-fetched, and so he had the webs come out of his wrist because he didn't want it to come out of any other body parts that spiders normally extrude their webbing from. Like out their butt or something, right? Yes. That would be a different movie wouldn't it would be a different movie but it might be hard to get it rated pg but spider web itself is an amazing material it has a strength a tensile strength the strength against being pulled apart five times greater than steel cable and it's

stretchier than nylon so it's's flexible steel, in a way. It is extremely flexible steel. If you had a steel thread as thin as a spider web, the spider web would be better than it by the fact that it's five times stronger. Correct. And scientists would dearly love to be able to artificially produce this, because then they could make lightweight clothing that would be stronger than Kevlar. There's all sorts of applications and things that we could do if we could mass produce this at will.

But Spidey... Spidey's able to do this on his own. On his own. He's able to do it, but it lacks a commercial aspect because it dissolves after an hour. Otherwise, the city would just be full of this stuff. Full of the webbies everywhere. You can't get rid of it, right? How do you throw it away?

You come out of the subway and instead of being covered in soot the way you are now, you'd be covered with spider webs. And so there's some fascinating science about little nanocrystals that provide strength and redundancy connected by flexible long-chain polymers that provide the stretchiness. So polymer, like nylon is a polymer, as an example. Long- chain carbon molecules right okay because carbon likes attaching to itself exactly so you're saying that the spider web is a polymer is that what you're saying it's a polymer that every given length has a very rigid

strong nanocrystalline block that's connected there oh so it's in segments essentially and and the nanocrystallites provide great strength, and the long-chain polymers provide the stretch. That sounds like the lost biblical tribe, the nanocrystallites. That's what that sounds like. We are the nanocrystallites. They were lost because they were so small.

We couldn't see them. So, let me ask you. Lee. Yes. Our molecular biologist at large, do you think that because we have greater sort of access to the, or at least, the future is a little closer today regarding molecular genetic engineering, do you think these superheroes are more realistic to us,

those that have these sort of genetic alterations that are within them? Well, we understand what spider webs are made out of, these special proteins that evolved in these little insects to allow them to walk around in thin air, apparently. Our problem is that our weight, just our basic weight is too high to develop a material that would do that. But we could probably secrete spider webs for whatever it would be worth. Can't wait. So do you have a plan for your next experiment?

Humans secreting spider... What you're saying is a spider is, however strong the spider web is, it's certainly strong enough for a spider, but it'd have to be much, much thicker to hold up a human being. To hold up you or me, it would have to be much, much thicker, and then it wouldn't be a spider web. Well, Spider-Man does admittedly have significantly thicker webs. Yes.

Admittedly. So are you saying that's realistic? We could make this stuff. Actually, it's a physicist about to tell me whether or not it could hold heavy weight. What you're saying is, since some biological creatures in the world can make spider webs, in principle, there's nothing that prevents humans from acquiring that same talent. Exactly. And, in fact, anything that any biological creature does that is special

could, in theory, be incorporated into a human being. So, for example, Daredevil can see the world in sound reflections because he's blind. Right. And he can see the world in sound reflections because he's blind. Right. And he can see the world. And, of course, bats do that. Exactly. So he'd make a good bat.

Right. And in theory, we could create that kind of phenomenon in man, although our ears would have to be very, very large. Now, there are other features of superheroes that are really kind of unrealistic in the world of what is real and unreal among superheroes, like elasticity, like, you know, Plastic Man and all this. Well, I actually wanted to say something about the elasticity. That's not totally unrealistic to a small degree. They're actually people who have elastic skin. I've seen that.

Ooh, they're creepy people. But couldn't they reach their arm across a room to get a soda pop? Not that elastic. Not that elastic. Yeah, and can they turn their entire body into like a trash can that will fool you on the street? Or as in the, what's the Disney movie with the superheroes? The Incredibles? The Incredibles, where Elastigirl becomes a parachute. Exactly.

Yeah, see, that'd be useful if you fall out of an airplane. Right. Let's go back to my interview with James Kakalios, because he talks about these stretching talents that superheroes have. You have Mr. Fantastic of the Fantastic Four. Remind me, what could he do with his body? He could stretch it into any shape. He had elastic powers. He had the same powers as Plastic Man.

Plastic Man stretches his body into any shape. At one point in one of the comics, one of the writers analyzed this and figured that these characters must not have any internal organs. Because the thought of what might happen to their cheeseburger that they ate at lunch while they were stretching into all sorts of different shapes led to too disturbing an image. So did you try to analyze the physics of the stretching? Well, you know, the stretching again, I will grant them suspension of disbelief. By the way, skin is a little bit stretchy, right? Look at a pregnant woman, the skin. It is absolutely stretchy. One aspect of the stretching that they get right, at least in the Fantastic Four, is that the further Mr. Fantastic would stretch his arms, the weaker he'd become. Oh.

And so there again, you know that if you— Wait, and isn't it true that his arm would get thinner? It would have to. Like Gumby. If you stretch Gumby, he gets thinner. That's exactly right. And so what would happen is you know that if you have a board supported on two posts and it's only a foot apart, the board is fine. But if the posts are a mile apart, the long plank is going to sag due to gravity. And so that the

strength is determined by the cross-sectional area. So the cross-sectional area is if you were to cut it and look at what faces you, like you're cutting an orange. Exactly. And so as he stretches it out, the cross-sectional area gets littler and littler and littler and you're losing strength. And it gets weaker and weaker because the strength of your muscles is determined by the cross-sectional area. That's why skinny people aren't as strong as people with big muscles. That's exactly right. And in fact, the big muscles, what matters is how fat the muscle is, how large the cross-sectional area, not how long it is. Right, right.

If you want to hold up a 40-pound fish with a 20-pound line, you don't get a longer line. You get a fatter line. Right, a stronger line. Exactly. Well, it's stronger because it's thicker. Because it's thicker. So who else stretched? In The Incredibles had Elastic Woman.

Another stretching character was the Elongated Man. That doesn't sound very creative. Well, there was one character who was super strong, and he had a code name called Strong Guy. who was super strong, and he had a codename called Strong Guy. So, Eugene, chatting earlier, you would seem to be intrigued by some of these cases of genetic mutants among humans that we already have on the record books. For example, there was Uber Baby, where in 1999, a baby was born in Germany. It was a mutation that changed the way the body controlled muscle growth. And so we've seen this in cattle before where they have double muscle cattle.

But this baby apparently was then born with super muscles. So my question is how strong is this baby? Like could the baby, like if the baby fought a bear, would the baby win? Or could the baby help you change your car tire? Yeah, exactly. Could it throw a car? Can this baby throw a car? The baby can lift itself up at a

very early age. That is such a boring power. A baby that can lift itself before another baby normally? Realistically, what could this, so the baby's now like four or so. So it can do chin-ups and push-ups. We need more than that if we're going to be a superpower baby.

Can it break sheetrock? It may be able to win some Olympic events. Okay. Against other babies or against adults? When we come back, we're going to talk about Superman. Lots of physics going on there. We'll see you in a moment. StarTalk Radio. We're talking about superheroes in this special episode. If you're going to be a superhero, you've got to have strength.

So let's go back briefly to my interview with James Kakalios and talk about the strength of superheroes and where that comes from and where it's going. Clearly you have the Hulk, you have Superman, you have Thor. In some cases you have Spider-Man, people who don't seem to have very large muscles and yet are extremely strong. They got away with that one because they said a spider has high strength relative to its legs. Yes. The other side of strength is when you look at characters who can shrink and still be able to punch with the same force as a normal person. Who would that be?

Well, Ant-Man. Okay, I missed that round of comics. Ant-Man? Ant-Man, there was a character. Who thought this up? Stan Lee. Ant-Man. Ant-Man who could shrink down to the size of an ant.

Oh, and then have the strength ratio that ants have. That must be it. Well. Because you've seen ants hauling sandwiches off your picnic. Not a whole sandwich, but you've seen an ant pull an entire potato chip down the alley. Yes, absolutely. Of course, ants do this in a very different way. They have an exoskeleton. They have their structure. So they're juicy on the inside and solid on the outside. Exactly. They're constructed in a very unique way,

which shrinking a person down to the size of an ant wouldn't necessarily buy you. Okay, so Ant-Man, they gave him great strength. They gave him strength. But informed by the biology of an ant. The other thing is, if you look at it, sometimes he's able to do things that aren't that far off. His muscles are much weaker when he's the size of an ant, but then his fists have a smaller surface area. So the force per area that he can actually provide. That would be the pressure.

The pressure would be exactly the same as the pressure that he would provide when he was normal size. Okay. So he's able to, say, punch his way out of a paper bag, which, believe it or not, turned out to be a crucial plot point. Oh, wow. Okay. I think James Kukali knows way too much about superheroes. He does know quite a bit. I feel like I know a fair amount, but he knows both the science and the stories dating back

I think we'd all have to agree that the most important superhero out there is Superman. He's strong. He can fly. He's got all the stuff you really need. He shoots lasers out of his face. He's very good at being a superhero. The man can do it. And so I had a special sort of interview segment with author of The Physics of Superheroes, James Kakalios.

Let's get right back into that interview and have him see what he says about Superman himself. So could you use physics principles to rate who the best superheroes are in terms of their power? I think it's got to be Superman. Well, Superman practically violates every law of physics. He not only is able to ignore gravity, but apparently can push against something when he needs to accelerate while he's flying. So he can just be floating in midair at some speed and then go faster. Exactly right. Without any propulsion.

There's an acceleration, but no force. Okay, so that violates every known law of motion. Yes. Right from there. Well, so does having bullets bounce off your flesh. You know, in the early days of Superman, he got his strength and his powers from coming from a planet with a larger gravity than Earth. So he was limited in the things he could do. Let me ask you, could he fly on Krypton?

No, because on Krypton... That was the heavy gravity. That was the heavy gravity. So just as our muscles and skeleton structure are adopted to Earth's gravity, so when we go to the moon... We're not quite flying, but we're doing pretty good. We can leap a moon building in a single bound and lift moon cars over our heads that astonish the moon people. Superman is able to do the same on Earth. Apparently, the rods and cones in his eye not only can detect X-rays, which is not really useful for us because there's so little X-rays in the solar spectrum that if we could see in the X-ray portion of the spectrum, we'd be constantly bumping into things.

But he can emit X-rays also apparently. Beam them out of his head. In his eyes. They pass through certain amounts of material but not others that are reflected back and enable him to see. You know what got me? And I don't know if I was just being too geeky. In the original Superman movie, the one with Christopher Reeve,

he's up being interviewed by Lois Lane in her penthouse apartment. And she says, you have x-ray vision? What color underwear am I wearing? He says, oh, I can't, I don't know.

So you don't have, no, because she's standing behind a lead planter. All right? So then she drifts away. Right. And he says, pink or something. I forgot the exact color.

It is pink. Oh, it is pink. Oh, so you knew. You remember? So you get the geek prize for this one. So if he has x-rays, how's x-ray going to, it's not going to see the color of her panties. No, that's. The x-rays would go right through the panties.

Exactly right. He could maybe the color of her panties. No, that's. The X-rays would go right through the panties. Exactly right. He could maybe basically check out her pelvic bone. Her pelvic bone, the marrow in her pelvic bone. Right. And the other notion that lead and only lead blocks his X-ray vision. X-rays scatter off of atoms depending on how many electrons they have. And the larger the atomic number of the atom, the more electrons. So gold would also be a good scatterer.

So those big elements that are on the periodic table, you don't just need lead. We use lead for shielding because when we used gold for shielding, they kept evaporating. It kept disappearing overnight. So you had to use something that was cheap and heavy. When you say evaporating, you mean culturally evaporating. Yes. People said, oh, I'd like some of this gold. You come in the next morning and it's gone. It's gone.

There it is, the full analysis of Superman. So, Eugene, this combination of talents that some we accept as kind of realistic. Well, earlier when he was talking about how he was like, well, elongated man and Mr. Plastic, or Plastic Man, that's unrealistic. That's somehow more unrealistic than Superman. Well, actually, I could imagine seeing pink panties, believe it or not, if you know what the pigment is that creates the color pink. And different pigments have different pigments. So you've been thinking about this ever since you've seen the movie, apparently.

So how can you tell if something is pink with extra vision? Well, you have to know what pigments they use. Yeah, different pigments would have different sort of atomic properties. Oh, I see. You would know the atomic properties of the underwear, and then you'd go, that's pink. That is a very smart alien. No, you would know the atomic properties of the pigment that colored the panties. Oh, I see.

It's different. I see. So in principle- In principle- I'm glad you figured out how it would be realistic. Yeah, Lee, is that what you do in your Princeton labs? I'd be fired if I did that. And the other thing is that the idea of creating x-rays.

There are animals that don't create x-rays, but they create life, fireflies. So in theory, we can create it. So fireflies, their light source is it has UV, right? There's UV in it, but not x-rays. No, no, no, not x-rays, but other kinds of photons. Oh, so you mean light that's outside of our

visible spectrum. And so if that's possible in principle. Yeah, and even in, I mean, it's all photons. So what we're saying is it is realistic to have echolocation, shoot spider webs, maybe even create a very bright light out of your face. Right. And be Batman.

This is not bad. And be superhumanly strong if you can be born with double muscles or remove the gene. Lee Silver, you're a professor of molecular biology at Princeton University. Lee, Lee Silver, you're a professor of molecular biology at Princeton University. And it sounds like you're a fan of all the various physical properties that the animal kingdom possesses. And are you after the genetic code of what enables this? And one day you want to splice that into humans and create a superhuman? Is this what you're doing in your lab?

It's all in my imagination. I mean, you know, as I said, anything in biology is possible. So it's fun to think about. If I came by Princeton, could you give me wings? Well, they're flying squirrels, you know. Not wings, but webs in their arms. Well, there's another superhero property, invisibility.

Even Harry Potter can do this with his special cloak. Well, he's magic. That's magic. That's different. So I had to get some get to the bottom line on this invisibility stuff. So let's go back to my interview with James and find out what he says about this special superhero property. There's the invisible woman. There's many characters who can turn invisible. One interesting question is when they're invisible, how are they still able to see? Because if light is passing through their body and not interacting or bending around

their body, visible light, visible light. Yes, exactly right. If you could see with radio waves, we'd be completely invisible because radio waves can pass through your body. Absolutely. And in fact, this is how I think that the invisible woman can see. You've analyzed this. I've thought about this much more than I probably should. The reason we could see anything is that the atoms and molecules in our body absorb and then re-emit light in the visible portion of the spectrum. Right. If she's able to shift that transition point into the ultraviolet portion of the spectrum, then the visible light would pass through the same way the visible light passes through a window. Yeah, a window. Exactly.

Right? But ultraviolet light would now be absorbed okay and so presumably if this is how she turns invisible then she's blind to visible light but can see the ultraviolet light that is still present it's significant that must be how she does it the next time i see her but of course the question is when is the next time you see the invisible woman? So in modern times, there are actually ways of becoming invisible. So for example, glass is fundamentally invisible.

Right. That's why we make windows out of it. So this notion of being invisible is not so foreign. It's not so technologically out of touch with our capacity to understand. Right. In fact, your building is invisible to radio waves and most microwaves. That's why your cell phone can ring indoors and annoy performers on stage. Cell phones don't see the walls. Cell phones raise the microwave.

They just pass right on through. I feel like this has given me a lot of hope for becoming a superhero. I feel like we're like, if I could figure out a way to turn to glass. So what they're working on now is a way to turn to glass. Or, so what they're working on now is a kind of material where the light enters, it hits your front,

but then gets passed around the side of you and comes out coherently on the other side. So if you're looking at that beam of light, you never knew that it actually went

around your body girth to get to you. And as far as you're concerned, you're seeing straight through you. But you have to be really narrow for that to work.

Well, it depends on how good the optics is and the curved light properties of the material that they put together. We've got to take a quick break, but more StarTalk Radio. Welcome back. So, do you want a cape? I do. Well, here's the thing about a cape.

It's one of the only things I can definitely do that a superhero has. Don a cape. I can put on a cape. I can't have claws. Can I have claws? Can I have claws come out of my hand? According to Lee, any other creature on Earth that has claws, he can hook you up with one one day with genetically engineered. Can some come out of my hands? We could put tissue on that does that, sure.

Tissue? Kleenex. Oh, oh, oh. He's a biologist. I see, I see. Biological tissue. Sure, that grows claws. Great.

Well, so basically, first step, I can get a cape, and I can be fireproof. We've actually done some research on capes. Oh. Yeah, movies have. And so there's no better expert than Edna on capes. You know Edna? Yes. You do?

Yes. Here she goes. Let's find out what she tells us about capes and superhero powers. Something classic, like Diner Guy. Oh. He had a great look. Oh, the cape and the boots. No capes.

Isn't that my decision? Do you remember Thunderhead? Tall, storm powers. Nice man. Good with capes. Isn't that my decision? Do you remember Thunderhead? Tall, storm powers, nice man, good with capes. Listen... November 15th of 58. All was well, another day saved, when his cape snagged on a missile. Thunderhead was not the brightest ball of the night. Stratogeal. April 23rd, 57. Cape caught in a jet turbine.

Hmm, you can't generalize about this thing. Metaman, express elevator, diner guy, snag on, take off, splash down, sucked into a vortex. No capes. Capes are bad, Eugene. Are there capes that can make you invisible? Oh, well, not, oh, oh, you mean are there in the government? Yeah, has the government made stuff that can make people seem invisible? I'm not authorized to answer that question.

Next. Are there invisible tanks? I'm not authorized. What exists that's sort of invisible? Invisible airplanes. I don't know, Eugene. I don't know. You made me ask you.

I asked you earlier, and you said, ask me on air. And now I asked you, and you're like, I don't know? You made me ask you. I asked you earlier and you said ask me on air and now I asked you and you're like I don't know? To embarrass me? I am not authorized to divulge that information. Alright. My access to top secret information. So there might be invisible capes and invisible

tanks and there might not. Which is what I already knew. The question is if I knew about one, would I tell you? That's the real question. Would you not just tell me? Would you tell the world? You know what else we've got going there? There's like people who change the temperature of things. That's kind of weird.

Yes, oven man. Let's go back to the final clip of my interview with James Kakalios, author of The Physics of Superheroes. Let's see what he says about ice. Find out. We have Frozone. How does he do that? Right.

Also, there's a character, the X-Men Iceman. They have ice powers, and it's described by their being able to change the local temperature around them so that what they're just doing is then freezing the water vapor that is present anyway.

And so they're not creating ice. That's how they can make these crystals there. They're not creating ice. They're lowering the temperature around them. So whatever's there freezes in place. Exactly right. So if you put them out in, say, the desert, their powers would be greatly reduced. Because there's not much moisture in the desert. Exactly right. And frozen sand is not that interesting. No, it isn't. Of course, there was Iceman and even Frozone would sometimes make these ice ramps that they would skate up. And frequently, the ramps would be supported on the ground, and then they would become very long.

And the character would be out at the end, way beyond the center of mass of the ramp. And in one comic, Iceman, in an informational page to the readers, said, Did I just hear a wise guy physics major ask what's keeping this up? What? Yep. And he said. He was talking to you. He was talking to me and he gave an answer I cannot argue with.

Imagination. Oh, that's a cop out. Oh, my God. So there it is, Eugene. Imagination makes it all happen. That's right. And James, in your biophysics labs, what role does, I mean, Lee, in your biophysics labs, what imagination,

what role does that play? Oh, imagination's everything. It's everything. You have to imagine things before you can discover them in what exists. Spoken like a true scientist on the frontier. Yes. Right, not doing just what everyone else has done. Science is art. Stepping where no one has stepped before. You know, this superhero

concept has worked its way into culture. And there are reports of people, bands of people, donning masks and capes and tights, trying to stop crime in various cities. There's one that caught my attention in Seattle. A, quote, superhero by the name of Phoenix Jones prevented a carjacking in January of this year. Complete with, like, you know, he's got a mask, he's got tights, and he's one of, like, eight members of the Rain City superhero movement. What does that even mean?

Do they work in conjunction with the police there? Or are they wanted like Batman? You have to be wanted, otherwise it's not sexy, you know? Well, at what point does that turn into being a vigilante? To be a creepy vigilante. And there's a turf battle there between the police and the vigilantes. So, yeah, I guess on some level we like the idea of superheroes protecting us, having special powers. I happen to really like the movie Invincible.

Oh, no. With Mr. Glass or something. Yeah. What was the name? Train. Danger Train. was the name? Train. Danger Train. The train. I forget.

It had Bruce Willis in it. It did, it did, and he was sort of magic. Invincible. Unbreakable. There we go. I like that one because he was just

There's so many people listening going, Unbreakable! I'm glad we got to it. Trying to slap me through the radio waves there. So, yeah, you know, as a kid, I wanted to be a superhero. I felt the urge to want to save people who were disenfranchised or taken advantage of. I didn't know if that was just me or other people.

It had to be plenty of people because the genre is hugely popular. Right. And it's fun to think about the science of it. I think it's fun to be helpful, but it's also fun to be magic. Yes. science of it. I think it's fun to be helpful, but it's also fun to be magic. Yes. So part of it is I'd love to help people, but mostly

I'd like to be able to jump from one building to another and be like, that worked. So you want to have superpowers but not actually save anybody. I would totally, if I had superpowers, save people, but I bet it would be an exhausting responsibility. That's what they don't say

in Spider-Man. We've got to wind down. Eugene, I want to thank you for coming back on the StarTalk Radio. You do great comedic work. And Lee, thanks for coming on the show. Oh, you're very welcome. Our biologists at large. We have to call you again one time.

Sure. You've been listening to StarTalk Radio. I'm Neil deGrasse Tyson. And as always, I bid you to keep looking up.