What's the Science of Invisibility?

he kept saying, I was wearing the juice. The juice, Well, apparently he poured lemon juice all over his face because he knew it could be used as this invisible ink for writing. And the poor guy, he was really bewildered because he said he tested it out, and the cops pressed him for details, and he said the lemon juice had gotten in his eyes the first time when he poured it all over his face, and then he took

a selfie to see if it had worked. And the combination of squinting and not being accustomed to taking his own photo, I mean, this this was well, it made him take a photograph that he wasn't in and he just believed that he was invisible. I know you almost feel bad for the guy, but you know, reading up on his invisible face juice made me wonder what is the science of invisibility and what are some of the things going on that we can't see? And where is

my invisibility cloak? So let's dive in. Hey, their podcast listeners, welcome to Part Time Genius. I'm Will Pearson and as always I'm joined by my good friend Man Guesh, I'll Ticketer and over there on the other side of the glass with the biggest smile that you can't see is Tristan McNeil, our producer, And on today's show, we're taking a WorldWind tour of our invisible world and trying to

get a better grasp of all things unseen. You know, the idea of invisibility is fascinated mankind for thousands of years. It's parts of our myths and our folklore and pop culture and even our psychology. Of course, there are lots of different kinds of invisibility, so this will be a super fun Hodgepodge episode where we cover as much as possible. We'll talk to a couple of insightful authors who have

devoted years of study to stuff we can't see. So who do we have on the line today, Mango, Today we're talking to Bob Berman, one of America's top astronomy writers and author of a brand new book about the curious history of invisible light. It's called Zapped, and it's incredible and we'll have some wonderful quizzes along the way as usual. All right, So, in honor of Bob's new book, I want to dive straight into the science and talk

about light, and more specifically invisible light. You know, obviously there are large portions of the electromagnetic spectrum that we have no trouble observing, but there's also a huge part that's totally invisible to us. That's the part that includes things like ultra violet light and for red light, radio waves, microwaves, X rays, gamma raves, you know, all that good stuff. Yeah. I mean, I always knew there were parts of the spectrum beyond our range of vision, just like you know

there's sounds outside the limits of human hearing. But reading Bob's book put the vastness of light in a completely new perspective for me, and it really blew me away. So Burman rights, there's more light in the universe than anything else. So if you were to add up every individual light photon in the cosmos, they would account for nine point of everything there is. And those forms of invisible light you listed off, that actually makes up the

vast majority of the light. I actually can't wrap my head around that fact that it seems unbelievable, but you know, our eyes are designed to recognize only the Sun's most abundant energy, so we really can only see the colors that the Sun emits most strongly. And even though the whole universe is light, the bulk of it, it's completely invisible to us. We've actually figured out all kinds of ingenious ways to measure and observe forms of invisible light.

And one of the most interesting things I came across while prepping for this episode was the way human observation actually affects the behavior of light. All right, well, I think this is pretty complicated, so why don't you break it down a little. Well. When quantum theory became all the rage in the twentieth century, scientists started noticing something super weird. They found that when they use special equipment to pinpoint the location of photons, these tiny bits of

matter always behaved as particles. For example, they could pass through one tiny hole or another in a barrier, but not through both holes at once. All right, so far, so good, and particles do what particles do that. I don't think there's anything weird about that, right, But the scientists also discovered that when they didn't try to determine the exact location of each photon, the photons behaved as

waves instead of particles. So the photons were then able to pass through both tiny holes in a barrier at the same time. And that's something that only waves can do, not particles. Okay, alright, I spoke through soon. That's really weird. And so you're saying that light, photons and other sub atomic matter act like particles, you know, when they know we're watching, and then like waves when they know we

aren't looking. Yeah, it's something like that. So obviously the photons themselves aren't aware of us watching them, but they definitely seem to act differently based on how closely we observe them. And the best explanation, at least according to most physicists, is that when we look closely, our brains halt the wave pattern so that we can see the photon in a certain place as a particle. It just makes us feel better that way. That's really insane, all right,

So where does that leave us? Does light exists as a wave or as tiny bits of almost invisible matter? Yeah, it's both. So Bob Berman sums up the paradox this way, and I'm going to quote him here. He says, just a century ago, the local realism mindset of science and even common sense held that all objects, including atoms and photons,

have an existence independent of our observation of them. But that's been replaced by a more modern view that our observation itself is necessary for the very existence of a photon or an electron. A spooky prospect, no kidding. Yeah, So he continues, it possessed no real existence as an actual photon or electron or whatever it was. Rather, it's observed existence is it's only existence. The observation establishes reality,

nothing else is certain. That's pretty trippy. Yeah, the stuff feels so philosophical, and especially when you go from a micro perspective to a macro one, because just like with photons, the color and brightness of light doesn't exist outside the experience of the observer. We only see light as a certain color because of how it stimulates the cones in our eyes and how our brain interprets those signals. Well, that's a good point, but it's also kind of a

terrifying mean. It means the external world is really just as invisible as a UV ray, because outside of human observation, there is no color or brightness. It's just this mix of different invisible energy pulses. Actually, by the way, that this is off topic, but did you read about the women that supposedly have four cones in their eyes instead of three, and as a result, they can see hundreds of millions of color. That's a wild Yeah, they're called tetrachromats.

But baby, we're clinging too tightly to the human experience. And you know, I actually did some digging to see if there were any animals whose vision best ours in terms of light perception, and it turns out there quite a few that put the invisible spectrum to pretty good use. Awesome, So give me the load down. Well, one case where plenty of animals have a speed is the ability to perceive ultra violet light. Invisible UV radiation is all around us.

And while it's useful for getting a golden tan, it's also a menace because exposure to it can lead to melanoma and other illnesses. But that hasn't stopped some animals from making the most of UV light. There's some species of birds that have plumage that you know, to our eyes look the same between males and females. But if your vision allows you to see the UV range like those birds are able to see it, you know you'd be able to make out the uvy markings that distinguish them.

So those markings make it easier for the birds to find a meh definitely, but that's actually only part of it. Some other birds determine which chicks to feed based on how much UV light you know their heads reflect. For whatever reason, the heartier birds tend to have a shinier crest than their weaker siblings, so when the mama bird has limited food to share, she'll go with whomever has

the most shine. There's also the fact that urine and feces of mice and other small prey are visible in the ultraviolet range, so birds that are sensitive to UV light can use these traces to track their prey even in a place where everything is uniform in color, you know, like a green field or something like that. But you know, birds aren't the only ones that can do this. You have rodents and bats and even some marsupials that can

see UV light for similar reasons. So I actually think I read something about butterflies also having great ev perception, and I think they use it to identify which flowers are currently producing nectar based on the color of the petals or something. Well, yeah, I'm glad you mentioned that, because butterflies with a high sensitivity light are often considered to have the widest visual range of any form of wildlife. It's crazy the invisible world might be the most visible

to butterflies of all things. But before we move on, there's one last animal I want to talk about, and that's the reindeer. So I'm sure there's a Rudolph joke in here somewhere, but not telling reindeer can see ev risk. Well, it sounds strange at first, but reindeer of evolved to take full advantage of the ultraviolet range. And they're not the only ones. There are other Arctic mammals who make their home at the Earth's polls, and they have to

deal with much higher levels of UV light. Yeah, the thinning ozone layer doesn't block as many rays as it used to, especially in those upper latitudes. Yeah, exactly. So there was this study of the University College of London and the University of Tromso in Norway, and they found evidence that not only a reindeer resistant eye damage from intense UV rays, they're also able to see UV light and this helps them find food and avoid predators. And

in the winter, reindeer primarily do two things. They eat lichen and they try to avoid being eaten by wolves. And wouldn't you know it, lichen and the fur of wolves both absorb UV light. So because snowy landscape strongly have reflect UV rays, you got reindeer that can spot

lichen and wolves with ease. Yeah. That's really cool, And well, I think you and I could nerd out on reindeer facts for a while, Like how Norwegian scientists wanted to get closer to reindeers so they could study them better, So they wore polar bear costumes and did that work. No, not at all, like it's scared off the reindeer. But they also wrote a scientific paper on reindeers reactions to costumes, and we're hoping to redo the study with better costumes,

like like a clown costume. I like how they just went off track there, Like that didn't work, So let's just do costumes. How about clowns? How about police officers? Science is great, but what I was saying was I think we should shift the topic a little. All right, well, what do you what do you want to talk about? Secret messages? So last year a group of scientists and friends developed a special kind of paper that can carry

secret messages. It looks just like plain old paper, but you can use different wavelengths of UV light to read, write, or even erase the messages that can't be seen invisible light. So how does that work? So apparently the paper has this special kind of molecule bonded to its cellulose fibers that reacts and turns fluorescent when exposed to UV light. The idea is you can write messages on the paper using a stencil to produce dark and bright areas that

react differently under the UV lamp. But the really cool thing is that the process is completely reversible. You can expose the used paper to a shorter wavelength of UV light that erases the message completely, and that way of paper can be used over and over. I mean, it is kind of cool, but what's the advantage over you know, the disappearing reappearing and visible length that our kids play with and stuff like that. So why is this better

than that? So not only are the messages on this paper undetectable under visible light, they also can't be dissolved with other chemicals. So it's the super useful tool in anti counterfeiting and tracking operations. A good job, France, you know. I actually want to dive into some of the historical obsession with invisibility and the ridiculous potions humans used to make.

But before we do that, how about we check in with Bob Burman and see if he can tell us a little about the cool properties of light and how humans have managed to turn something invisible to our advantage. So in this episode on All Things Invisible, we've been talking a little bit about this great book, Zapped, and we're really lucky to have one America's top astronomy writers on with us and the author of this book. It's Zapped From infrared to X rays, The Curious History of

invisible Light. Bob Berman, Welcome to part time genius. Thank you great to be here. All right, well let's just start with the basics. So can you explain to us where light comes from. Well, all lights, except for gamma rays, comes from one source only, and that is atoms. If the atomy gets excited in any way, electricity, collisions, anything can may be excited, madam, so that the electrons are In the case of hydraten, it's only got one electron

jumps to a higher orbit because it's excited. It really doesn't like to be there. So in a fraction of the second, it'll tumble down closer to its nucleus, and that is what causes any kind of light. And the distance that it tumbles down determines the color of the light and therefore whether it's visible or invisible. So I know you talk about this in your book, but what did ancient people think about light? And were they aware

of invisible light? They felt about light as at first something that comes from the eye, and then later on as an interaction between a beam from the eye and external objects. So they got it wrong for a long time. They realized that it involves something very fast speed, but nothing more than that, and nobody foresaw invisible light until

the time of the Renaissance of the Middle Ages. It was one of those things that no wise person or Greek philosopher, or scientists or religious order, nobody came up with the idea that there might be kinds of light out there that our eyes can't see well. In the Renaissance, as you mentioned, you know, with this idea of invisible light being a possibility, how did this start to be discovered? Well,

it's really William Herschel who found the first kind. He projected sunlight through a prism piece of cut glass onto a tabletop, so you had the whole rainbow of colors. And then he put a thermometer in each color, and he had other themometers on the side in the darkness to act as controls. And so he noticed that when the thermometer was in the blue or the green part of the spectrum, the temperature went up very little. In the yellow and went up more, and the red they

went up still more. But then he took a break, and when he came back some minutes later, the sun had moved across the sky, so the spectrum on the table had shifted, and now his thermometer on the table was no longer in the visible light instead of was sitting in a spot of darkness outside of the spectrum, just beyond the red end of the spectrum. And he looked down on it, and now the thermometer was crazy. Who had it was registering much more heat than any

color did. And so he repeated this and he realized that the blank spot beyond the red part of the spectrum was heat, was producing more heat. Well, he realized it had to be an invisible kind of light that was creating the heat. And he called these calorific rays. Later on we came to call it infrared. So that was the first kind of invisible light ever discovered. Wow. Wow. And you also talked in the book about the discovery of of X rays and I'm curious what the you know,

the public response was to this discovery. Well, X rays, Yeah, that changed the world too. That was Renkin, and he was boy. He had fame, and he would have had fortune too if he had patented it, but he didn't.

Generously just allowed the world to use it, and almost right away people realized the value in medicine that you could use X rays and find a bullet wear a bullet was my body for someone who had been shot or were broken, bones were broken, And but nobody knew at the time that X rays also had a dark side,

that it could produce harm as well as benefits. What new opportunities for the use of invisible light are the horizon and things like medicine or technology or culture, well everywhere you know, we use that more than visible light these days. Everybody knows about microwaves and used in for not just our ovens, but for broadcasting on the GPS signals that come down to us from the radio part of the spectrum. Really the microwave part of the spectrum.

So whenever we use our GPS in our cars, or when when we're on a camping trip, or use our cell phones, those are all parts of the radio spectrum. And then we know about the infrared. We use heat labs, we use garage door openers, that are they're using infrared and ultra violet. That's boy, that's the one with the two edged sword. Ultra violet is both the most dangerous

form and the most valuable for our health. And what makes UV rays so harmful to us, Well, they're the beginning of the part of the spectrum that has the power to ionize and others to strip electrons from adams and therefore to change genes, to change chromosomes, to alter DNA, and that could give rise to cancer, and it does the eight thousand or so melanoma deaths per year. Skin cancer are caused by generally too much UV, usually from

from from a bad sudden burn in our youth. And uh, and that's why people nowadays know that they should be putting on sunscreen and wearing hats and stuff like that. But bad thing has happened from that too, in that we've now blocked so much of the UV. That's strange things are happening to our bodies that that most even doctors are not aware of, although many are like like, like what you do have some examples of this? Yeah, yeah,

and this has started. If I could give just a bit of background, There was a time, of course, when we were an agricultural society and we were out of doors a lot, and we got plenty of sunlight and therefore plenty of ultravolet, which is a few percent of the sunlight and stimulates our bodies to produce U V a vitamin D very quickly. That UV induced vitamin D is such a avalanchingly fast process that we get more U V from twenty minutes in the strong sunlight then

you would from drinking two hundred glasses of milk. So somehow our bodies want lots of vitamin D production from UV. It's a natural thing. But as we moved indoors to be a manufacturing society, and then starting in the fifties and sixties had air conditioning so that we didn't have to open windows, and glass blocks UV and so it

blocks the vitamin D production on our skin. And then worst of all, this is something that they Vitamin D Council talks about a lot because the doctors there, like John Cannell like are really getting frustrated with the fact that we've turned into kind of a race of of of mold people where we're blocking the sun entirely and not getting enough sunlight. They see it that it wasn't

that many decades ago. The kids after school. Of course, during school they're not getting any UV and therefore not producing any vitamin D. But after school kids used to play outdoors and parents used to say, yeah, come back at dinner time, and between they'd be out doing whatever in the playground or climbing trees, and then that changed, so their UV levels in their and their blood has dropped to really, really low levels. So what does this do is turns out that u V is one of

the strongest prevent ers of cancer. It stops cancers from growing, so when they're tiny, pre detectable tumors, they don't get any bigger. This year, for example, it was found that pancreatic cancer is prevented by by adequate vitamin D triggered by ultra violet light. So there are a lot of health benefits also psychological benefits in terms of treatment for depression and and things like that. If you get enough sunlight induced h vitamin D, it's hard to strike that

strike that perfect balance. Now you're so right. At the same time, you don't want to burn. So the people like Dr Canell in the Vitamin D Council, they say that we should get as much sun as we can without burning, because everybody is so different and how much sun they can handle before they start to burn. You know, blue eyed, blonde people tend to burn fast, and camp shouldn't get as much. Well, there are a thousand other questions we could ask. This such a fascinating book. I

hope all of our listeners will check out zapp. But Bob, thanks so much for joining us on Part Time Genius. It's been a pleasure. Thanks so much. You're listening to Part Time Genius and we're talking about the peculiar allure of turning invisible, So mego. We mentioned at the top of the show that humans have been obsessed with the idea of invisibility from millennia, so I thought it might be fun to take a look at some of the weirdest attempts to go invisible that people have tried all

over the years. Yeah, so I'm definitely game. I spent some time looking up medieval recipes and spells to turn yourself invisible, and as you might guess, they're insane. So one of my favorites is from the Ashmole, which is this anonymous fifteenth century manuscript that collected over a hundred eighty magical and magical recipes in English and Latin. So

this is the invisibility spell. It goes, if you wish to be invisible, take a dead dog and bury it, and plant a bean plant over it, and place one in your mouth, and without a doubt you'll be invisible. That that's it. It's simple. It's like one of these great invisibility life hacks. But but don't worry. If you're fresh out of dead dogs or beans, there's another suggestion for you. Um this is also from the Middle Ages.

Grind up an owl's eye with the ball of beetle dung and some olive oil and rub it all over your body. I like the addition of the olive oil, like weird stuff, and you just put some olive oil in there that I think I'd rather eat the dead dog being So why do they all have to be so gross? So most invisibility charms that ties to a cult practices so they tend to feature nasty ingredients like the ivan a for a heart of a bat or whatever. And one of them actually calls for the head of

someone who committed suicide, but stuffed with fava beans. God, it's hard to imagine why any of these ingredients were picked to be the ones that would turn you invisible, But I don't know, and think about it. Might have something to do with our desire for power, which seems to be at the root of man's continuing quest for invisibility. I mean, we have stories going all the way back

to antiquity that point to the dark side of going invisible. Yeah, so there are all kinds of myths and folk legends that warn about the corrupting power invisibility and how it can lead even the most pure of heart heroes into recklessness or voyeurism. And well, you know, these commonalities between fables from different cultures. I find these fascinating. In this case. They seem to suggest that we all know invisibility as a power that we probably shouldn't have, and you know,

it doesn't stop us from wanting it though. And in fact, the top two superpowers that people always cite is the ones they'd most like to have, are the ability to fly and the power to turn invisible. Yeah. So both of those provide the user a crazy amount of freedom, and maybe that's why we find them appealing. You know, that could definitely be the case. But in keeping with the shady side of invisibility we've been talking about that

there might be another explanation. And I couldn't find an actual psychological study of this, but there is some speculation about what the choice between flight and invisibility says about a person. William Barry was this psychotherapist and professor at Florida International University. He suggests that people who opt to go invisible are embracing their dark side, you know, the side of themselves that they typically don't like to acknowledge

as being part of them. So this is the side of your psyche where all your most shameful thoughts and desires dwell. According to Barry, quote many of those who choose invisibility do so to hear what others say about them when they aren't around, or to spy on others, or to procure things that they don't have the money to pay for. It's easy to see how this relates

to the dark side. Yeah, it really is, especially when you compare it to choosing flight, which is mostly appealing as this form of fast travel or experiencing this different sensation, but it doesn't seem to have any of the darker edge, right And you know, Barry found that people who choose power of flight generally see it as a way to add excitement or fulfillment to their lives, whether that's from you know, maybe rescuing people from burning buildings or just

zipping across the world to have dinner in Italy or you know, something like that, which is interesting. You know, there's another commonality between invisibility fables that we should probably talk about, all right, and what's that invisibility cloaks. So ancient Greek myths described caps and cloaks with magical properties that made the were invisible to other mortal men, and from their invisibility, cloaks have popped up in everything from

Welsh and Germanic folklore to modern day pop culture. Of course, and I'm guessing being a big fan, you think of Harry Potter definitely, so Harry Potter is never far from my mind. But scientists have been hard at work on cloaking devices for a while now, things that can mask or completely hide an object or a person from sight.

And sometimes they're more successful than others, but all of the most promising ones involved something called meta materials, and it's just you know, some kind of super science cloth or something more or less. So meta materials are basically a kind of material that's engineered to have properties that that don't occur in nature, and in this case, it's a light bending property that manipulates the eye. So the reason objects are visible to our eyes at all is

because objects distort light waves based on their shapes. But when the light from an object reaches our eyes, we see the object by recognizing those distortions. Alright, so meta materials they somehow counteract this or so. The idea is that the meta material forms a kind of shell around the object, or a cloak, so the light rays bends smoothly around the meta material and recombined on the other side.

And one helpful example I came across is that it's kind of like water flowing around a rock and a stream. I viewer on the far side wouldn't see anything unusual, but both the meta materials shield and object in its center would be completely invisible to him. It would look like the lights bouncing off a smooth surface, which is pretty cool. But I don't know. I have the say, I've read so many headlines over the last few years that claim we're this much closer to Harry Potter like

invisibility cloak. And you know, there are definitely some similarities to what you're describing, but it's hardly a one to one I mean, I mean, natural materials get their special properties from the arrangement of atoms and there's no way what's going on with these meta materials is the same thing. Yeah, that's true, And these cloaking devices are more like chunky rings and pyramids that fit over a stationary object right now, rather than any sort of sleek piece of fabric. But

the technology is advancing pretty quickly. Well, I'm glad to know that we're on our way towards that. But why don't we break for a little quiz? Alright, So today's show us about invisibility. We decided to bring on to Seattle based artists who produced the delightful art series that only shows up when it rains. Welcome to the show, Peregon Church and Zach Fisher. Thank you great to be here.

I am so excited to have you on. And and for you listeners who aren't familiar with rain Works, you should definitely check out the photo gallery at www dot rain dot works because it's fantastic. So can you tell us a little bit about how you came up with this idea of making invisible artwork that only shows up in the rain. I love thinking of ways to use materials that already exist in ways that they shouldn't be used.

And I came across this stuff called super hydrophobic coatings. Basically, when you put it on the surface, he keeps it from getting wet. And I thought, wow, that's super cool. You're watching all this water roll off these clothes and

shoes and whatever. What if you put it on something that changed color when it got wet, like concrete and so you since it's a spray on the thing, you could spray it through a stencil on the concrete and as long as it was invisible and dry, you can create art that was only visible when the surface is wet. Would you tell our listeners a little bit about some of the designs you do and how you make them interactive? Sure, we like to do things that are positive, things that

don't make someone stay better. That's are really one of the big motivations behind it. Because in Seattle and the Pacific Northwestern general, people tend to suffer from sad seasonal effect of disorder. The skies are gray and it's dreary and wet all the time. So we figured we could take that thing that causes the juriess the rain and

use it to make people smile. We did a lock nest monster at a at a dock out in over a lake here in Seattle Green Lake so that people could stumble upon the monster while they were out on rainy days. We do games. Sometimes you've done like it Don't Touch the Lava game. Um, We've done like nostalgic references to like characters that we love as like when we were kids. So like we've done like a Peter Pan rainwork, and like the Calvin and Hobbs rain work.

Basically just whatever we think would like cheer someone up or make them smile or make them think when they see it it's funny. I mean even hearing the examples makes you smile. That's pretty great. And you've now turned this into a business. So what are the best applications of your rain works? And you know that you've seen in the wild now, oh man, we've seen so many from all over the world. Some people have done like promposals or actual wedding proposals with them. We've seen people

use public sountains to make like dolphins that appear. Yeah, there's one just like a day or two ago where they coated a canvas with it and through water balloons with like water based paint in them, through do a gender reveal. Right back that was what that was. Yeah, Yeah, that kind of works a little differently because our spray doesn't repel paint, but it like reacted with it in a certain way, so it does kind of make the letters pop, but like not in the way you expect.

It's really interesting to see like a new application for it, and that's really been the coolest thing is like just since this started, it's really taken off just all around the world, and we get like new one's popping up in like Denmark and like Taiwan and like Armenia. Does having worked on this project make you look forward to rainy days? Like do you sit on benches waiting for people to interact with the art? Oh? Absolutely. It has

completely changed our perspective on rainy days. And one of our favorite things to hear when we tell people about project is them the words coming out of their mouths, oh my gosh, I can't wait till it rains now, Like that means the world to us. We become so hyper sensitive to it that every time it starts to rain or like the forecast predicts range, like we're like on the edge of our chieves, like we're preparing, we're making work, our our whole work as well, depends on

the weather. For sure. We'll tell us a little bit about your connection with the Awesome Foundation. Sure. When I had this idea, it was just an idea, like on a note in my phone for a long time, but it was one of one of my favorites, and I started mentioning it to people and eventually mentioned it to a friend in Seattle who was part of the Seattle

chapter of the Awesome Foundation. For anyone doesn't know, the Awesome Foundation is an organization that every month it's one dollars the person with a cool idea or an awesome idea, as they put it, No, it's things attached. So I submitted this rain activated our idea, but we're not called rain works do the Austin Foundation, And they accepted it, and that was what really gave it the first push.

All right, well, I thought we should play a little game with these guys, and Mango, you came up with one that's appropriate from what what game are we playing with a Peregrine and Zach, it's called I'm Only have you in it rains? All right, we love your rainy Day project, and we figured we'd give you a quiz where all the answers involved rain and you can work together on this. So you guys, ready, ready, alright? He

got five questions for you, all right. Number one, Gene Kelly had a one hundred and three degree fever when he danced the big number in this rainy movie. What classic film are we talking about? For one? Number two, Prince's manager questioned the decision to put When Doves Cry and this movie slash album because the song didn't have a baseline and he didn't think it would be a hit. What Prince movie are we talking about? Purple? Yes? Alright?

Number three? All these culture references and depending on yours action, he's really pulling through alright. Number three. During the filming of this award winning movie, both Tom Cruise and Dustin Hoffman thought the flick would be a clunker. The whole time. They referred to it as two schmucks in a car. What movie are we talking about? Wait? I got this one, Ramon, alright with the big answer, here we go. Number four. Before this actor won the role of Dwight Shrut on

the office seth Rogan had auditioned for the role. Who are we talking about? Wilson? Yes, they both got that one, all right. The last question see if you can get the perfect score number five. This song, written by Paul Shaffer and performed by the Weather Girls, was intended to be a gay anthe much like Y M c A. You know the name of the song, It's rain Man. Yes, alright.

How did they do a mango our ols when astounding five for five, which means we'll be sending them our top prize, a handwritten note to their mom or boss singing their praises congratulations, m thanks so much. Yeah, that's awesome. Listeners, please check out rain dot works when you get a second, and thank you guys so much for all the work you do and for putting smiles on so many faces

having us. Okay, well, so we talked about fictional invisibility cloaks as well as the closest things we have two real life ones. But there's one more thing I want to talk about, and it's the psychological sort kind of a psychological invisibility quote. I don't even know how that would work. Is like a helmet that would block your brain waves or something like that. Yeah that's a good guess,

but no, nothing like that. I'm actually talking about the great study I came across about a nomena called it invisibility cloak illusion, and that's the name researchers at Yale University came up with for our mistaken belief that we

observe others way more than others observe us. All Right, so this is kind of like us pretending that maybe we're under invisibility cloaks when we're out in public, if we're grocery shopping or walking our dogs or something like that, exactly pretty much any time we're in public, really, So

the team describes it this way, and they're abstract. Quote, whether at a coffee shop, in a waiting room, or riding the bus, people frequently observe the other people around them, Yet they failed to realize how much other people engage in the same behavior, and that they therefore also are being observed. Because it's logically impossible that people, on average are the subjects of observation more than they are objects of it. The belief that one watches others more than

one is watched is an illusion that's pretty wild. I mean, we feel like we're invisible when the fact that we observe others should tell us just the opposite. Of this, And I really can't understand why we make this silly mistake, because it's just that we're egoman acts, and you know, we think we're the observant person and the only observant person in the room. Yeah, that's definitely part of it. But at least there's a good reason why we think

that way. And why is that? Well, the researchers that Yale concluded that social norms compel our neighbors to pretend to be busy with something else if it looks like we might catch them watching us. All right, so we've secretly scoped out the competition at a job interview, or a glance around the waiting room and a doctor's office, and you know, just in case we need an alibi,

we have a magazine or something like that. It's funny that we all assume we're the only ones who do this, though, Right, so when it's actually so widespread and phenomena that it even has its own name, researchers call it civil and attention. I kind of like that. Yeah, But my favorite part of the study is this line from the conclusion, however irresistible the sensation of being invisible, maybe it is not

to be trusted. That sounds exactly right, and it actually makes it me think of this this other study I read on the logic of the game Peekaboo. Apparently it's this great display of the kind of nonsensical logic that most kids share, namely the idea that you can make yourself invisible by just covering your own eyes. So the study was what like scientists rounded up a bunch of toddlers and had this epic peekaboo session, Not exactly, but

but kind of. So the researchers at the University of Cambridge had a group of three and four year olds where I'm asked, and then they asked them whether they could be seen by researchers or if they were invisible

to them. Then they asked the kids whether the researchers would be able to see adults if those adults were wearing eyemask like their's, and unsurprisingly, nearly all the kids said they were hidden from view while their eyes were covered, and most of them actually thought the imask would make the adults invisible too, which is super cute. But did the researchers have any ideas for why almost every child subscribes to that weird logic. Well, actually, here's where things

get really interesting. And because when kids had their eyes covered, they felt invisible, which fair enough, I mean, I think we've all heard that before. But the researchers started to press them on what invisibility meant, and surprisingly, the kids conceded that their bodies weren't actually hidden it all. In the sixth so they admitted their bodies could still be seen even when their eyes were covered. So what do they mean by invisible? Well, that's the weirdest part and

where this gets a little deep here. So the implication was that the kids felt it was their true self that was being hidden from view. So basically, they were saying, I know, you can still see my arms and my legs and all that when my eyes are closed, but you can't see me, which is which is pretty existential, you know, I know. It's it's like the children share some natural distinction between, you know, the physical body and the metaphysical self. And I just find this stuff fascinating.

And you know, because most adults tend to think of their consciousness and their body being joined together in some way, and studies like this suggests that perception might be something we only adopt or maybe decide on later in life. Yeah, that's especially interesting when you think about how people always say the eyes of the window to the soul, or that eye contact Foster's understanding. I mean, in some ways, covering your eyes really is like withdrawing yourself from the

world and making yourself from visible. Alright, well, Mango, you need to keep those eyes open, because there's only one thing you can't hide from, the PGG fact off exactly. All right, here's something I hadn't thought about. Any lightbeam weapon you see in the movies, from photon torpedoes to invisible rays, they're all things you won't see coming. So anytime a sci fi hero is in a jet dodging

those rays, none of that's possible. You know that some of the things you see in movies you just ruined all movies did so I want to know a figure who's basically become invisible. Jeremiah Dummer. Most people know Yale University is named for Elihu Yale, but Dumber probably did more for the early university in terms of securing funds and building its reputation. The problem is, Dumber College isn't a great name. While reindeer are good at spotting polar bears.

Cameras aren't, so when scientists decided to use infrared cameras to locate the bears, they were stunned. But polar bears are basically invisible to infrared cameras too. While cameras can pick up the heat off their nose and their breath, their blubber basically does such a good job of trapping the heat within that their fur is essentially the same temperature as all the snow around it. So despite all the safety features and cars with backup cameras and beeping sensors,

people still back up into lampos. So researchers at Kyo University in Japan have come up with back seats that actually turned transparent when you back up. Basically, it's a backup camera that projects on the seats, but it does the trick of seeming transparent and of course making the children sitting in those seats disappear as another matter, definitely, all right, here's a fun one about not being seen. A building supervisor in Spain skipped work for six years

and kept collecting his salary. You know the only reason he got caught. People got suspicious when he won an award for twenty years of loyal service. In two thousand and six, magician David Copperfield and his two assistants were walking down the street when Mugger's approached and demanded all their money and wild assistants forked over plane tickets, cell phones, and over five in cash. Copperfield used sleight of hand to show the gun wielding robbers that his pockets were empty.

He reperformed the trick at the police station and wow the officers, showing them he actually had a passport and lots of cash on him the whole time. I know he's such a performer, but he did help catch the bad guys and I kind of love it all right. Well, in that case, I'm gonna have to give you today's championship belt. So that's it for today's episode. Thanks so

much for listening, Thanks again for listening. Part Time Genius is a production of how stuff works and wouldn't be possible without several brilliant people who do the important things we couldn't even begin to understand. Chris and McNeil does the editing thing. Noel Brown made the theme song and does the MIXI mixy sound thing. Jerry Rowland does the

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