August 7, 2026 • 42 mins
Sure, invisibility is about magic cloaks and invisible inks. But it’s so much more than that! From the way butterflies see a secret world of light that humans can’t, to the real reason polar bears are completely undetectable to infrared cameras, there’s a whole big world you ought to hear about… even if you can’t see it. Featuring author Bob Berman.
This episode originally aired on September 1, 2017.
Buy Bob's book, Zapped: From Infrared to X-rays, the Curious History of Invisible Light.
Got a question or idea for the show? Call our hotline at (302) 405-5925 or email higeniuses@gmail.com.
Follow us on Instagram @parttimegenius and Bluesky @parttimegenius.bsky.social!
There's an episode thumbnail image. You just can't see it.
Learn more about your ad choices at https://www.iheartpodcastnetwork.com.
See omnystudio.com/listener for privacy information.
Listen
Watch
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:00):
Guess what mango, what's that will? I was reading this old.
Speaker 2 (00:03):
Story about a bank robbery that happened in nineteen ninety five.
So this guy walks into two banks, one after the other.
He has no mask and no face cover. I mean,
it didn't seem like he was trying to hide himself.
And he gets caught on camera pretty clearly, and so
obviously he's apprehended not long after that. But the weird
thing is when the cops come from he was totally baffled.
Speaker 3 (00:24):
Oh yeah, why not?
Speaker 1 (00:25):
Well, he kept saying, I was wearing the juice.
Speaker 3 (00:28):
The juice.
Speaker 2 (00:29):
Well, apparently he'd 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'd said he'd 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
(00:49):
the combination of squinting and not being accustomed to taking
his own photo, I mean, this was nineteen ninety five. Well,
it made him take a photograph that he wasn't in
and he.
Speaker 1 (00:58):
Just believed that he was invisible.
Speaker 2 (01:00):
Oh no, 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.
(01:37):
I'm Will Pearson and as always I'm joined by my
good friend Manguesh.
Speaker 1 (01:40):
How ticket there and over there on.
Speaker 2 (01:41):
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.
Speaker 1 (01:57):
It's parts of our.
Speaker 2 (01:58):
Myths and our folklore and pop culture and even our psychology.
And 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've devoted years of study to
stuff we can't see.
Speaker 1 (02:15):
So who do we have on the line today, Mango.
Speaker 3 (02:17):
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 Zappt and
it's incredible, and we'll have some wonderful quizzes along the
way as usual.
Speaker 2 (02:28):
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. 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,
(02:50):
you know, all that good stuff.
Speaker 3 (02:52):
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 writes, there's more light in the universe than
anything else. So if you were to add up every
individual light, photon and the cosmos, they would account for
(03:14):
ninety nine point nine nine nine nine percent of everything
there is in those forms of invisible light you listed off.
That actually makes up the vast majority of the light.
Speaker 2 (03:23):
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 its completely invisible to us.
Speaker 3 (03:42):
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.
Speaker 2 (03:54):
All right, well, I think this is pretty complicated, so
why don't you break it down a little.
Speaker 1 (03:58):
Well.
Speaker 3 (03:58):
When quantum theory became all the rage and 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.
Speaker 1 (04:16):
All right, so far, so good, and particles do what
particles do that. I don't think there's anything weird about.
Speaker 3 (04:21):
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.
Speaker 1 (04:37):
Okay, all right, I spoke too soon. That's really weird.
Speaker 2 (04:40):
And so you're saying that light, photons and other subatomic
matter act like particles, you know, when they know we're watching,
and then like waves when they know we aren't looking.
Speaker 3 (04:49):
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.
Speaker 2 (05:09):
That's really insane, all right, So where does that leave us?
Does light exist as a wave or as tiny bits
of almost invisible matter?
Speaker 1 (05:15):
Yeah, it's both.
Speaker 3 (05:16):
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
(05:39):
photon or an electron. A spooky prospect, yeah, no kidding. Yeah,
So he continues, it possessed no real existence as an
actual photon or electron or whatever it was. Rather, its
observed existence is its only existence. The observation establishes reality,
nothing else is certain.
Speaker 1 (05:56):
Oh that's pretty trippy, magues.
Speaker 3 (05:57):
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.
Speaker 2 (06:16):
Well, that's a good point, but it's also kind of
a terrifying I 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, and 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,
(06:38):
they can see hundreds of millions of colors. That's a
wild Yeah, they're called tetrachromats. But baby, we're clinging too
tightly to the human experience, you know. I actually did
some digging to see if there were any animals whose
vision best ores in terms of light perception, and it
turns out there are quite a few that put the
invisible spectrum to pretty good use.
Speaker 3 (06:57):
Awesome, So give me the lowdown.
Speaker 2 (06:58):
Well, one case where plenty of animals have a speed
is the ability to perceive ultraviolet 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 plumaged that you know,
(07:20):
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 UV markings
that distinguish them.
Speaker 3 (07:31):
So those markings make it easier for the birds to
find the meat, Oh.
Speaker 1 (07:34):
Definitely, But that's actually only part of it.
Speaker 2 (07:36):
Some other birds determine which chicks to feed based on
how much UV light you.
Speaker 1 (07:40):
Know their heads reflect.
Speaker 2 (07:42):
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.
Speaker 1 (07:52):
There's also the.
Speaker 2 (07:52):
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 you 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
(08:14):
for similar reasons.
Speaker 3 (08:16):
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
like the color of the petals or something.
Speaker 2 (08:26):
Well, yeah, I'm glad you mentioned that, because butterflies with
a high sensitivity to 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.
Speaker 3 (08:45):
So I'm sure there's a Rudolph joke in here somewhere,
but not tell it. But reindeer can see ev rays.
Speaker 2 (08:51):
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.
Speaker 3 (09:04):
Yeah, the thinning ozone layer doesn't block as many rays
as it used to, especially in those upper latitudes.
Speaker 1 (09:09):
Yeah, exactly.
Speaker 2 (09:10):
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 to eye
damage from intense UV.
Speaker 1 (09:19):
Rays, they're also able to see UV.
Speaker 2 (09:22):
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 landscapes strongly
of reflect UV rays, you've got reindeer that can spot
lichen and wolves with these.
Speaker 3 (09:43):
Yeah, that's really cool. And while 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 costas.
Speaker 1 (09:54):
And did that work?
Speaker 3 (09:55):
No, not at all, Like it's scared off the reindeer.
But they also wrote scientific paper on reindeer's reactions to costumes,
and we're hoping to redo the study with better costumes.
Speaker 1 (10:05):
Yeah, 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?
Speaker 3 (10:13):
Science is great, but what I was saying was I
think we should shift the topic a little.
Speaker 1 (10:16):
All right, well, what do you want to talk about?
Speaker 3 (10:18):
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 in
visible light.
Speaker 1 (10:33):
So how does that work?
Speaker 3 (10:34):
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
(10:56):
shorter wavelength of UV light that erases the message completely,
and that way the paper can be used over and over.
Speaker 1 (11:01):
I mean that is kind of cool.
Speaker 2 (11:03):
But what's the advantage over you know, the disappearing reappearing
invisible link that our kids play with and stuff like that.
Speaker 1 (11:09):
So why is this better than that?
Speaker 3 (11:11):
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 this super useful tool in anti counterfeiting and
tracking operations.
Speaker 1 (11:21):
Ah, good job, France.
Speaker 2 (11:23):
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,
(11:45):
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 Zapp From Infrared to X Rays, The Curious History
of Invisible Light. Bob Berman, Welcome to Part time Genius.
Speaker 4 (12:00):
Well, thank you, great to be here.
Speaker 2 (12:01):
All right, well, let's just start with the basics. So
can you explain to us where light comes from.
Speaker 4 (12:06):
Well, all light, except for gamma rays, comes from one
source only, and that is atoms. If the atom gets
excited in any way, electricity, collisions, anything can maybe excited
atom so that the electrons or in the case of hydrogen,
has only got one electron, jumps to a higher orbit
(12:26):
because it's excited, it really doesn't like to be there,
so in a fraction of a 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.
Speaker 3 (12:47):
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?
Speaker 4 (12:54):
They thought 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 with a very fast speed, but
nothing more than that. And nobody foresaw invisible light until
(13:19):
the time of the Renaissance of the Middle Ages. It
was one of those things that no wise person or
Greek philosopher or scientist 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.
Speaker 2 (13:37):
In the Renaissance, as you mentioned, you know, with this
idea of invisible light being a possibility, how did this
start to be discovered?
Speaker 4 (13:44):
Well, it was 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 thermometers on the side in the darkness
to act as controls. And so he noticed that when
(14:06):
the thermometer was in the blue or the green part
of the spectrum, the temperature went up but very little.
In the yellow it 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
(14:27):
was no longer in the visible light. Instead, it was
sitting in a spot of darkness outside of the spectrum,
just beyond the red end of the spectrum. And they
looked down on it, and now the thermometer was crazy.
It was registering much more heat than any color did.
And so he repeated this and he realized that the
(14:51):
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.
Speaker 5 (15:12):
Wow.
Speaker 1 (15:13):
Wow.
Speaker 2 (15:13):
And you also talk in the book about the discovery
of X rays and I'm curious what the you know,
the public response was to this discovery.
Speaker 4 (15:21):
Well, X rays, Yeah, that changed the world too. That
was Renkin, and he was the 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
(15:42):
find a bullet where a bullet was in my body
for someone who had been shot, or where broken bones
were broken. But nobody knew at the time that X
rays also had a dark side, that it could produce
harm as well as benefits.
Speaker 3 (15:57):
What new opportunities for the use of invisible light are
on the horizon and things like medicine or technology or culture.
Speaker 4 (16:03):
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
(16:25):
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 they're using infrared. Ultraviolet. That's boy,
that's the one with the two edged sword. Ultraviolet is
(16:47):
both the most dangerous form and the most valuable for
our health.
Speaker 1 (16:53):
And what makes UV raise so harmful to us.
Speaker 4 (16:56):
Well, they're the beginning of the part of the spectrum
that has the power to ionize and others to strip
electrons from atoms 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
(17:17):
per year. Skin cancer are caused by generally too much UV,
usually from from a bad sun burn in our youth.
And and that's why people nowadays know that they should
be putting on sunscreen and wearing hats and stuff like that.
(17:37):
But bad thing has happened from that too, in that
we've now blocked so much of the UV that strange
things are happening to our bodies that most even doctors
are not aware of, although many are.
Speaker 1 (17:52):
Like, like, what you do you have some examples of that?
Speaker 4 (17:56):
Yeah, yeah, And this is 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 ultraviolet, which is a few percent
of the sunlight, and it stimulates our bodies to produce UV,
(18:17):
a vitamin D very quickly. That UV induced vitamin D
is such a avalanchingly fast process that we get more
UV from twenty minutes in the strong sunlight than you
would from drinking two hundred glasses of milk. So somehow
our bodies want lots of vitamin D production from UV.
(18:40):
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
we're of all. This is something that the Vitamin D
(19:03):
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 mole
people where we're blocking the sun entirely and not getting
enough sunlight. They see it that it wasn't that many
decades ago that kids after school. Of course, during school
(19:24):
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 on the playground
or climbing trees, and then that changed, so their UV
levels and their blood has dropped to really, really low levels.
(19:47):
So what does this do is turns out that UV
is one of the strongest preventors 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 by
(20:11):
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.
Speaker 1 (20:31):
Vitamin D, it's hard to strike strike that perfect balance.
Speaker 4 (20:36):
No, you're so right. At the same time, you don't
want to burn. So the people like doctor Canill and
the Vitamin D Council, they say that we should give
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
(20:57):
people tend to burn fast and can it shouldn't get
as much.
Speaker 2 (21:02):
Well, there are a thousand other questions we could ask.
Is this is 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.
Speaker 4 (21:11):
Oh it's been a pleasure. Thanks so much.
Speaker 2 (21:26):
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.
Speaker 3 (21:42):
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 one hundred and eighty magical
and not magical recipes in English and Latin. So this
(22:02):
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.
Speaker 1 (22:14):
And that's it.
Speaker 3 (22:16):
It's simple. It's like one of these great invisibility life hacks.
But don't worry. If you're fresh out of dead dogs
or beans, there's another suggestion for you. 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.
Speaker 2 (22:32):
I like the addition of the olive oil with weird stuff,
and you just put some olive oil in there.
Speaker 1 (22:36):
I think I'd rather eat the dead dog bean. So
why do they all have to be so gross?
Speaker 3 (22:41):
So most invisibility charms that ties to occult practices, so
they tend to feature nasty ingredients like the im an
a or 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.
Speaker 2 (22:53):
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.
Speaker 3 (23:12):
Yeah, so there are all kinds of myths and folk
legends that warnt about the corrupting power of invisibility and
how it can lead even the most pure of heart
heroes into recklessness or voyeurism.
Speaker 2 (23:23):
And well, you know these commonalities between fables from different cultures.
Speaker 1 (23:27):
I find these fascinating. In this case.
Speaker 2 (23:28):
They seem to suggest that we all know invisibility is
a power that we probably shouldn't have, and you know,
that 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.
Speaker 3 (23:44):
Yeah. So both of those provide the user a crazy
amount of freedom, and maybe that's why we find them appealing.
Speaker 2 (23:50):
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 visibility
says about a person. William Barry's this psychotherapist and professor
at Florida International University. He suggests that people who opt
(24:12):
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 as well. 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
(24:34):
the money to pay for. It's easy to see how
this relates to the dark side.
Speaker 3 (24:38):
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.
Speaker 2 (24:48):
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 wor world to have dinner
in Italy, or you know, something.
Speaker 3 (25:01):
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 describe
caps and cloaks with magical properties that made the we're
invisible to other mortal men. And from their invisibility, cloaks
have popped up in everything from Welsh and Germanic folklore
(25:23):
to modern day pop culture.
Speaker 2 (25:25):
Of course, and I'm guessing, being a big fan, you're
thinking of Harry Potter.
Speaker 3 (25:28):
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
are more successful than others. But all of the most
promising ones involve something called meta materials.
Speaker 1 (25:46):
And is this, you know, some kind of super science cloth.
Speaker 3 (25:48):
Or something more or less. So, meta materials are basically
a kind of material that's engineered to have properties 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
(26:09):
the object by recognizing those distortions, all.
Speaker 1 (26:12):
Right, So meta materials they somehow counteract this.
Speaker 3 (26:16):
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 view were on
the far side wouldn't see anything unusual, but both the
meta materials shield and the object in its center would
(26:39):
be completely invisible to them. It would look like the
lights bouncing off a smooth surface, which is pretty cool.
Speaker 1 (26:45):
But I don't know.
Speaker 2 (26:45):
I have to say, I've read so many headlines over
the last few years that claim were 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, 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.
Speaker 3 (27:06):
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.
Speaker 1 (27:17):
Well, I'm glad to.
Speaker 2 (27:18):
Know that we're on our way toward that. But why
don't we break for a little quiz and.
Speaker 1 (27:23):
Then all right, So s today's show is about invisibility.
Speaker 2 (27:29):
We decided to bring on two Seattle based artists who
produced the delightful art series that only shows.
Speaker 1 (27:35):
Up when it rains. Welcome to the show, Peregrin Church
and Zach Fisher.
Speaker 5 (27:39):
Thank you great to be here.
Speaker 3 (27:40):
I am so excited to have you on. 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.
Speaker 5 (27:59):
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 a surface, it 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
(28:21):
changed color when it got wet, like concrete? And so
since it's a spray on thing, you could spray it
through a stencil onto concrete and as long as it
was invisible when dry, create art that was only visible
when the surface was wet.
Speaker 3 (28:35):
Would you tell our listeners a little bit about some
of the designs you do and how you make them interactive?
Speaker 5 (28:39):
Sure, we like to do things that are positive, things
that don't make someone stay better. That's our really one
of the big motivations behind it because in Seattle and
the Pacific Northwest in general, people tend to suffer from
sad seasonal effect disorders.
Speaker 6 (28:54):
The skies are.
Speaker 5 (28:55):
Gray and it's dreary and wet all the time. So
we figured we could take that thing that causes the
gurius the rain and use it to make people smile.
Speaker 6 (29:04):
We did a lock messed monster 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, we've done
like a don't touch the lava game. We've done like
nostalgic references to like characters that we love as like
(29:26):
when we were kids. So like we've done like a
Peter Pan rain work and like Calvin and Hobbes rain work.
Basically just whatever we think would like cheer someone up
or make them smile or make them think when they see.
Speaker 1 (29:38):
It, it's funny.
Speaker 2 (29:39):
I mean even hearing the examples makes you smile. That's
pretty great, man. 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?
Speaker 6 (29:49):
Now, oh man, we've seen so many from all over
the world.
Speaker 5 (29:54):
Some people have done like promposals their actual wedding proposals
with them. We've seen people use public fountains to make
like dolphins that appear. Yeah, there was one just like
a day or two ago where they coated a canvas
with it and then through water balloons with like water
based paint in them to do a gender reveal, right.
Speaker 2 (30:14):
Zack, that was what that was.
Speaker 6 (30:15):
Yeah, Yeah, that kind of worked 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
(30:37):
just all around the world, and we get like new
one's popping up in like Denmark and like Taiwan and
like Armenia.
Speaker 3 (30:44):
Does having worked on this project make you look forward
to rainy days? Like do you sit on benches waiting
for people to interact.
Speaker 1 (30:50):
With the art?
Speaker 3 (30:51):
Oh?
Speaker 5 (30:51):
Absolutely. It has completely changed our perspective on rainy days.
And one of our favorite things to hear when we
tell people about this 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.
Speaker 6 (31:09):
That's so we become so hyper sensitive to it that
every time it starts to rain or like the forecast
predictions range, like we're like on the edge of our sets,
like we're preparing. We're making our whole work agital depends
on the weather, for sure.
Speaker 1 (31:24):
Well, tell us a little bit about your connection with
the Awesome Foundation.
Speaker 4 (31:29):
Sure.
Speaker 5 (31:29):
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 Autome Foundation. If anyone doesn't know,
the Awesome Foundation is an organization that every month it's
(31:54):
one thousand dollars to the person with a cool idea
or an awesome idea, as they put its attached. So
I submitted this rain activated our idea but were not
called rainworks to the Austin Foundation, and they accepted it,
and that was what really gave it the first push.
Speaker 2 (32:11):
All right, Well, I thought, uh, 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?
Speaker 1 (32:18):
With a Peregrine and zach Vi.
Speaker 3 (32:19):
It's called.
Speaker 2 (32:22):
All right, we love your Rainy Day project, and we
figured we'd give you a quiz where all the answers
involve rain.
Speaker 1 (32:27):
And you can work together on this. So you guys ready, okay,
you ready?
Speaker 6 (32:31):
All right?
Speaker 1 (32:33):
I got five questions for you, all right.
Speaker 2 (32:34):
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?
Speaker 6 (32:44):
Singing in the rain? Yea for one?
Speaker 1 (32:46):
Number two.
Speaker 2 (32:48):
Prince's manager questioned the decision to put When Doves Cry
in this movie slash album because the song didn't have
a bassline and he didn't think it would be a hit.
Speaker 1 (32:56):
What Prince movie are we talking about? Yes?
Speaker 3 (33:01):
All right?
Speaker 1 (33:01):
Number three?
Speaker 5 (33:02):
All these culture references and depending on your action, he's really.
Speaker 1 (33:07):
Pulling through, all right. Number three.
Speaker 2 (33:10):
During the filming of this award winning movie, both Tom
Cruise and Dustin Hoffman thought the flick would be a clunker.
Speaker 1 (33:16):
The whole time.
Speaker 2 (33:17):
They referred to it as two schmucks in a car.
What movie are we talking about?
Speaker 1 (33:23):
Wait?
Speaker 5 (33:23):
I got this one, Raymond?
Speaker 1 (33:25):
All right with the big answer, here we go. Number four.
Speaker 2 (33:31):
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
Schaeffer and performed by the Weather Girls, was intended to
be a gay ant to, much like y mc A.
(33:53):
You know the name of the song.
Speaker 5 (33:54):
It's men.
Speaker 1 (33:55):
Yes, all right, how did they do?
Speaker 3 (33:58):
Mango als went 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.
Speaker 1 (34:09):
Thanks so much for them. Yeah, that's awesome, guys, that'd
be great.
Speaker 3 (34:16):
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.
Speaker 6 (34:24):
For having us.
Speaker 3 (34:37):
Okay, well, so we talked about fictional invisibility cloaks as
well as the closest things we have to real life ones.
But there's one more thing I want to talk about,
and it's the psychological.
Speaker 1 (34:45):
Sort kind of a psychological invisibility quote. I don't even
know how that would work.
Speaker 2 (34:50):
Is it like a helmet that would block your brain
waves or something like that?
Speaker 3 (34:53):
Yeah, that's a good guess. But no, nothing like that.
I'm actually talking about the great study I came across
about a No, I'm gonna called it invisibility cloak illusion,
and that's the name researchers that Yale University came up
with for our mistake and belief that we observe others
way more than others observe us.
Speaker 2 (35:09):
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 out grocery shopping or walking our dogs.
Speaker 3 (35:18):
Or something like that, exactly pretty much anytime 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 fail 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
(35:41):
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.
Speaker 1 (35:48):
It's pretty wild.
Speaker 2 (35:49):
I mean, we feel like we're invisible when the fact
that we observe others should tell us.
Speaker 1 (35:53):
Just the opposite of this.
Speaker 2 (35:55):
And I really can't understand why we make this silly mistake,
because it just that we're ego main and you know,
we think we're the observant person and the only observant
person in a room.
Speaker 3 (36:04):
Yeah, that's definitely part of it. But at least there's
a good reason why we think that way.
Speaker 1 (36:08):
And why is that?
Speaker 3 (36:09):
Well, the researchers at 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.
Speaker 2 (36:18):
All right, so we've secretly scoped out the competition at
a job interview or a glance around the waiting room
in a doctor's office, and just in case we.
Speaker 1 (36:25):
Need an alibi, we have a magazine or something like that.
Speaker 2 (36:28):
It's funny that we all assume we're the only ones
who do this, though.
Speaker 3 (36:32):
Right, so, when it's actually so widespread of 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.
Speaker 2 (36:48):
That sounds exactly right, and it actually makes me think
of 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.
Speaker 3 (37:04):
So the study was what scientists rounded up a bunch
of toddlers and had this epic peekaboo session.
Speaker 1 (37:09):
Not exactly but but kind of.
Speaker 2 (37:12):
So the researchers at the University of Cambridge had a
group of three and four year olds wear imasks, 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 theirs,
and unsurprisingly, nearly all the kids said they were hidden
from view while their eyes were covered, and most of
(37:34):
them actually thought the ie mask.
Speaker 3 (37:35):
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.
Speaker 2 (37:43):
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 at all in.
Speaker 3 (38:00):
The way way. So they admitted their bodies could still
be seen even when their eyes were covered. So what
do they mean by invisible?
Speaker 2 (38:06):
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.
Speaker 3 (38:21):
See me, which is pretty existential.
Speaker 1 (38:25):
Yeah, I know, I know.
Speaker 2 (38:26):
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 suggest
that perception might be something we only adopt or maybe
decide on later in life.
Speaker 3 (38:46):
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 visible.
Speaker 2 (39:00):
All right, well, Mango, you need to keep those eyes open,
because there's only one thing you can't hide from the.
Speaker 7 (39:05):
PGG fact off exactly.
Speaker 1 (39:18):
All right, here's something I hadn't thought about.
Speaker 2 (39:20):
Any light beam 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 and
a jet dodging those rays, none of that's possible.
Speaker 3 (39:31):
You know that some of the things you see in movies,
you just ruined all movies I 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 Dummer probably did more for the early university in
terms of securing funds and building its reputation. The problem is,
Dummer College isn't a great name.
Speaker 2 (39:51):
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. His 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
(40:12):
all the snow around it.
Speaker 3 (40:14):
So despite all the safety features and cars with backup
cameras and beeping sensors, people still back up into lamposts.
So researchers at Kyo University in Japan have come up
with back seats that actually turn 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
(40:34):
making the children sitting in those seats disappear as another matter.
Speaker 1 (40:37):
Definitely, all right, here's a fun one about not being seen.
Speaker 2 (40:40):
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.
Speaker 3 (40:52):
In two thousand and six, Magician David Copperfield and his
two assistants were walking down the street when muggers approached
and demanded all their money. And while the assistants forked
over plane tickets, cell phones, and over five hundred dollars
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 wowed the officers,
(41:12):
showing them he actually had a passport and loss of
cash on him the whole time. I want to I
know he's such a performer, but he did help catch
the bad guys and I kind of love it all right.
Speaker 2 (41:23):
Well, in that case, I'm going to have to give
you today's championship belt.
Speaker 1 (41:26):
So that's it for today's episode.
Speaker 7 (41:28):
Thanks so much for listening.
Speaker 1 (41:43):
Thanks again for listening.
Speaker 2 (41:44):
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.
Speaker 3 (41:51):
Christa McNeil does the editing thing.
Speaker 2 (41:53):
Noel Brown made the theme song and does the mixy
mixy sound thing carry Roland does the exec producer thing.
Gave blues you or our lead researcher, with support from
the Research Army including Austin Thompson, Nolan Brown and Lucas Adams.
Speaker 3 (42:05):
And Eves Jefcok gets the show to your ears. Good job, Eves.
Speaker 2 (42:08):
If you like what you heard, we hope you'll subscribe,
and if you really really like what you've heard, maybe
you could leave.
Speaker 1 (42:12):
A good review for us.
Speaker 3 (42:13):
Do we forget Jason?
Speaker 1 (42:15):
Jason who
Guess what mango, what's that will? I was reading this old.
Speaker 2 (00:03):
Story about a bank robbery that happened in nineteen ninety five.
So this guy walks into two banks, one after the other.
He has no mask and no face cover. I mean,
it didn't seem like he was trying to hide himself.
And he gets caught on camera pretty clearly, and so
obviously he's apprehended not long after that. But the weird
thing is when the cops come from he was totally baffled.
Speaker 3 (00:24):
Oh yeah, why not?
Speaker 1 (00:25):
Well, he kept saying, I was wearing the juice.
Speaker 3 (00:28):
The juice.
Speaker 2 (00:29):
Well, apparently he'd 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'd said he'd 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
(00:49):
the combination of squinting and not being accustomed to taking
his own photo, I mean, this was nineteen ninety five. Well,
it made him take a photograph that he wasn't in
and he.
Speaker 1 (00:58):
Just believed that he was invisible.
Speaker 2 (01:00):
Oh no, 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.
(01:37):
I'm Will Pearson and as always I'm joined by my
good friend Manguesh.
Speaker 1 (01:40):
How ticket there and over there on.
Speaker 2 (01:41):
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.
Speaker 1 (01:57):
It's parts of our.
Speaker 2 (01:58):
Myths and our folklore and pop culture and even our psychology.
And 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've devoted years of study to
stuff we can't see.
Speaker 1 (02:15):
So who do we have on the line today, Mango.
Speaker 3 (02:17):
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 Zappt and
it's incredible, and we'll have some wonderful quizzes along the
way as usual.
Speaker 2 (02:28):
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. 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,
(02:50):
you know, all that good stuff.
Speaker 3 (02:52):
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 writes, there's more light in the universe than
anything else. So if you were to add up every
individual light, photon and the cosmos, they would account for
(03:14):
ninety nine point nine nine nine nine percent of everything
there is in those forms of invisible light you listed off.
That actually makes up the vast majority of the light.
Speaker 2 (03:23):
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 its completely invisible to us.
Speaker 3 (03:42):
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.
Speaker 2 (03:54):
All right, well, I think this is pretty complicated, so
why don't you break it down a little.
Speaker 1 (03:58):
Well.
Speaker 3 (03:58):
When quantum theory became all the rage and 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.
Speaker 1 (04:16):
All right, so far, so good, and particles do what
particles do that. I don't think there's anything weird about.
Speaker 3 (04:21):
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.
Speaker 1 (04:37):
Okay, all right, I spoke too soon. That's really weird.
Speaker 2 (04:40):
And so you're saying that light, photons and other subatomic
matter act like particles, you know, when they know we're watching,
and then like waves when they know we aren't looking.
Speaker 3 (04:49):
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.
Speaker 2 (05:09):
That's really insane, all right, So where does that leave us?
Does light exist as a wave or as tiny bits
of almost invisible matter?
Speaker 1 (05:15):
Yeah, it's both.
Speaker 3 (05:16):
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
(05:39):
photon or an electron. A spooky prospect, yeah, no kidding. Yeah,
So he continues, it possessed no real existence as an
actual photon or electron or whatever it was. Rather, its
observed existence is its only existence. The observation establishes reality,
nothing else is certain.
Speaker 1 (05:56):
Oh that's pretty trippy, magues.
Speaker 3 (05:57):
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.
Speaker 2 (06:16):
Well, that's a good point, but it's also kind of
a terrifying I 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, and 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,
(06:38):
they can see hundreds of millions of colors. That's a
wild Yeah, they're called tetrachromats. But baby, we're clinging too
tightly to the human experience, you know. I actually did
some digging to see if there were any animals whose
vision best ores in terms of light perception, and it
turns out there are quite a few that put the
invisible spectrum to pretty good use.
Speaker 3 (06:57):
Awesome, So give me the lowdown.
Speaker 2 (06:58):
Well, one case where plenty of animals have a speed
is the ability to perceive ultraviolet 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 plumaged that you know,
(07:20):
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 UV markings
that distinguish them.
Speaker 3 (07:31):
So those markings make it easier for the birds to
find the meat, Oh.
Speaker 1 (07:34):
Definitely, But that's actually only part of it.
Speaker 2 (07:36):
Some other birds determine which chicks to feed based on
how much UV light you.
Speaker 1 (07:40):
Know their heads reflect.
Speaker 2 (07:42):
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.
Speaker 1 (07:52):
There's also the.
Speaker 2 (07:52):
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 you 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
(08:14):
for similar reasons.
Speaker 3 (08:16):
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
like the color of the petals or something.
Speaker 2 (08:26):
Well, yeah, I'm glad you mentioned that, because butterflies with
a high sensitivity to 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.
Speaker 3 (08:45):
So I'm sure there's a Rudolph joke in here somewhere,
but not tell it. But reindeer can see ev rays.
Speaker 2 (08:51):
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.
Speaker 3 (09:04):
Yeah, the thinning ozone layer doesn't block as many rays
as it used to, especially in those upper latitudes.
Speaker 1 (09:09):
Yeah, exactly.
Speaker 2 (09:10):
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 to eye
damage from intense UV.
Speaker 1 (09:19):
Rays, they're also able to see UV.
Speaker 2 (09:22):
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 landscapes strongly
of reflect UV rays, you've got reindeer that can spot
lichen and wolves with these.
Speaker 3 (09:43):
Yeah, that's really cool. And while 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 costas.
Speaker 1 (09:54):
And did that work?
Speaker 3 (09:55):
No, not at all, Like it's scared off the reindeer.
But they also wrote scientific paper on reindeer's reactions to costumes,
and we're hoping to redo the study with better costumes.
Speaker 1 (10:05):
Yeah, 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?
Speaker 3 (10:13):
Science is great, but what I was saying was I
think we should shift the topic a little.
Speaker 1 (10:16):
All right, well, what do you want to talk about?
Speaker 3 (10:18):
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 in
visible light.
Speaker 1 (10:33):
So how does that work?
Speaker 3 (10:34):
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
(10:56):
shorter wavelength of UV light that erases the message completely,
and that way the paper can be used over and over.
Speaker 1 (11:01):
I mean that is kind of cool.
Speaker 2 (11:03):
But what's the advantage over you know, the disappearing reappearing
invisible link that our kids play with and stuff like that.
Speaker 1 (11:09):
So why is this better than that?
Speaker 3 (11:11):
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 this super useful tool in anti counterfeiting and
tracking operations.
Speaker 1 (11:21):
Ah, good job, France.
Speaker 2 (11:23):
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,
(11:45):
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 Zapp From Infrared to X Rays, The Curious History
of Invisible Light. Bob Berman, Welcome to Part time Genius.
Speaker 4 (12:00):
Well, thank you, great to be here.
Speaker 2 (12:01):
All right, well, let's just start with the basics. So
can you explain to us where light comes from.
Speaker 4 (12:06):
Well, all light, except for gamma rays, comes from one
source only, and that is atoms. If the atom gets
excited in any way, electricity, collisions, anything can maybe excited
atom so that the electrons or in the case of hydrogen,
has only got one electron, jumps to a higher orbit
(12:26):
because it's excited, it really doesn't like to be there,
so in a fraction of a 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.
Speaker 3 (12:47):
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?
Speaker 4 (12:54):
They thought 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 with a very fast speed, but
nothing more than that. And nobody foresaw invisible light until
(13:19):
the time of the Renaissance of the Middle Ages. It
was one of those things that no wise person or
Greek philosopher or scientist 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.
Speaker 2 (13:37):
In the Renaissance, as you mentioned, you know, with this
idea of invisible light being a possibility, how did this
start to be discovered?
Speaker 4 (13:44):
Well, it was 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 thermometers on the side in the darkness
to act as controls. And so he noticed that when
(14:06):
the thermometer was in the blue or the green part
of the spectrum, the temperature went up but very little.
In the yellow it 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
(14:27):
was no longer in the visible light. Instead, it was
sitting in a spot of darkness outside of the spectrum,
just beyond the red end of the spectrum. And they
looked down on it, and now the thermometer was crazy.
It was registering much more heat than any color did.
And so he repeated this and he realized that the
(14:51):
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.
Speaker 5 (15:12):
Wow.
Speaker 1 (15:13):
Wow.
Speaker 2 (15:13):
And you also talk in the book about the discovery
of X rays and I'm curious what the you know,
the public response was to this discovery.
Speaker 4 (15:21):
Well, X rays, Yeah, that changed the world too. That
was Renkin, and he was the 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
(15:42):
find a bullet where a bullet was in my body
for someone who had been shot, or where broken bones
were broken. But nobody knew at the time that X
rays also had a dark side, that it could produce
harm as well as benefits.
Speaker 3 (15:57):
What new opportunities for the use of invisible light are
on the horizon and things like medicine or technology or culture.
Speaker 4 (16:03):
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
(16:25):
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 they're using infrared. Ultraviolet. That's boy,
that's the one with the two edged sword. Ultraviolet is
(16:47):
both the most dangerous form and the most valuable for
our health.
Speaker 1 (16:53):
And what makes UV raise so harmful to us.
Speaker 4 (16:56):
Well, they're the beginning of the part of the spectrum
that has the power to ionize and others to strip
electrons from atoms 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
(17:17):
per year. Skin cancer are caused by generally too much UV,
usually from from a bad sun burn in our youth.
And and that's why people nowadays know that they should
be putting on sunscreen and wearing hats and stuff like that.
(17:37):
But bad thing has happened from that too, in that
we've now blocked so much of the UV that strange
things are happening to our bodies that most even doctors
are not aware of, although many are.
Speaker 1 (17:52):
Like, like, what you do you have some examples of that?
Speaker 4 (17:56):
Yeah, yeah, And this is 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 ultraviolet, which is a few percent
of the sunlight, and it stimulates our bodies to produce UV,
(18:17):
a vitamin D very quickly. That UV induced vitamin D
is such a avalanchingly fast process that we get more
UV from twenty minutes in the strong sunlight than you
would from drinking two hundred glasses of milk. So somehow
our bodies want lots of vitamin D production from UV.
(18:40):
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
we're of all. This is something that the Vitamin D
(19:03):
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 mole
people where we're blocking the sun entirely and not getting
enough sunlight. They see it that it wasn't that many
decades ago that kids after school. Of course, during school
(19:24):
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 on the playground
or climbing trees, and then that changed, so their UV
levels and their blood has dropped to really, really low levels.
(19:47):
So what does this do is turns out that UV
is one of the strongest preventors 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 by
(20:11):
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.
Speaker 1 (20:31):
Vitamin D, it's hard to strike strike that perfect balance.
Speaker 4 (20:36):
No, you're so right. At the same time, you don't
want to burn. So the people like doctor Canill and
the Vitamin D Council, they say that we should give
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
(20:57):
people tend to burn fast and can it shouldn't get
as much.
Speaker 2 (21:02):
Well, there are a thousand other questions we could ask.
Is this is 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.
Speaker 4 (21:11):
Oh it's been a pleasure. Thanks so much.
Speaker 2 (21:26):
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.
Speaker 3 (21:42):
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 one hundred and eighty magical
and not magical recipes in English and Latin. So this
(22:02):
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.
Speaker 1 (22:14):
And that's it.
Speaker 3 (22:16):
It's simple. It's like one of these great invisibility life hacks.
But don't worry. If you're fresh out of dead dogs
or beans, there's another suggestion for you. 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.
Speaker 2 (22:32):
I like the addition of the olive oil with weird stuff,
and you just put some olive oil in there.
Speaker 1 (22:36):
I think I'd rather eat the dead dog bean. So
why do they all have to be so gross?
Speaker 3 (22:41):
So most invisibility charms that ties to occult practices, so
they tend to feature nasty ingredients like the im an
a or 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.
Speaker 2 (22:53):
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.
Speaker 3 (23:12):
Yeah, so there are all kinds of myths and folk
legends that warnt about the corrupting power of invisibility and
how it can lead even the most pure of heart
heroes into recklessness or voyeurism.
Speaker 2 (23:23):
And well, you know these commonalities between fables from different cultures.
Speaker 1 (23:27):
I find these fascinating. In this case.
Speaker 2 (23:28):
They seem to suggest that we all know invisibility is
a power that we probably shouldn't have, and you know,
that 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.
Speaker 3 (23:44):
Yeah. So both of those provide the user a crazy
amount of freedom, and maybe that's why we find them appealing.
Speaker 2 (23:50):
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 visibility
says about a person. William Barry's this psychotherapist and professor
at Florida International University. He suggests that people who opt
(24:12):
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 as well. 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
(24:34):
the money to pay for. It's easy to see how
this relates to the dark side.
Speaker 3 (24:38):
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.
Speaker 2 (24:48):
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 wor world to have dinner
in Italy, or you know, something.
Speaker 3 (25:01):
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 describe
caps and cloaks with magical properties that made the we're
invisible to other mortal men. And from their invisibility, cloaks
have popped up in everything from Welsh and Germanic folklore
(25:23):
to modern day pop culture.
Speaker 2 (25:25):
Of course, and I'm guessing, being a big fan, you're
thinking of Harry Potter.
Speaker 3 (25:28):
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
are more successful than others. But all of the most
promising ones involve something called meta materials.
Speaker 1 (25:46):
And is this, you know, some kind of super science cloth.
Speaker 3 (25:48):
Or something more or less. So, meta materials are basically
a kind of material that's engineered to have properties 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
(26:09):
the object by recognizing those distortions, all.
Speaker 1 (26:12):
Right, So meta materials they somehow counteract this.
Speaker 3 (26:16):
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 view were on
the far side wouldn't see anything unusual, but both the
meta materials shield and the object in its center would
(26:39):
be completely invisible to them. It would look like the
lights bouncing off a smooth surface, which is pretty cool.
Speaker 1 (26:45):
But I don't know.
Speaker 2 (26:45):
I have to say, I've read so many headlines over
the last few years that claim were 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, 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.
Speaker 3 (27:06):
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.
Speaker 1 (27:17):
Well, I'm glad to.
Speaker 2 (27:18):
Know that we're on our way toward that. But why
don't we break for a little quiz and.
Speaker 1 (27:23):
Then all right, So s today's show is about invisibility.
Speaker 2 (27:29):
We decided to bring on two Seattle based artists who
produced the delightful art series that only shows.
Speaker 1 (27:35):
Up when it rains. Welcome to the show, Peregrin Church
and Zach Fisher.
Speaker 5 (27:39):
Thank you great to be here.
Speaker 3 (27:40):
I am so excited to have you on. 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.
Speaker 5 (27:59):
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 a surface, it 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
(28:21):
changed color when it got wet, like concrete? And so
since it's a spray on thing, you could spray it
through a stencil onto concrete and as long as it
was invisible when dry, create art that was only visible
when the surface was wet.
Speaker 3 (28:35):
Would you tell our listeners a little bit about some
of the designs you do and how you make them interactive?
Speaker 5 (28:39):
Sure, we like to do things that are positive, things
that don't make someone stay better. That's our really one
of the big motivations behind it because in Seattle and
the Pacific Northwest in general, people tend to suffer from
sad seasonal effect disorders.
Speaker 6 (28:54):
The skies are.
Speaker 5 (28:55):
Gray and it's dreary and wet all the time. So
we figured we could take that thing that causes the
gurius the rain and use it to make people smile.
Speaker 6 (29:04):
We did a lock messed monster 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, we've done
like a don't touch the lava game. We've done like
nostalgic references to like characters that we love as like
(29:26):
when we were kids. So like we've done like a
Peter Pan rain work and like Calvin and Hobbes rain work.
Basically just whatever we think would like cheer someone up
or make them smile or make them think when they see.
Speaker 1 (29:38):
It, it's funny.
Speaker 2 (29:39):
I mean even hearing the examples makes you smile. That's
pretty great, man. 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?
Speaker 6 (29:49):
Now, oh man, we've seen so many from all over
the world.
Speaker 5 (29:54):
Some people have done like promposals their actual wedding proposals
with them. We've seen people use public fountains to make
like dolphins that appear. Yeah, there was one just like
a day or two ago where they coated a canvas
with it and then through water balloons with like water
based paint in them to do a gender reveal, right.
Speaker 2 (30:14):
Zack, that was what that was.
Speaker 6 (30:15):
Yeah, Yeah, that kind of worked 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
(30:37):
just all around the world, and we get like new
one's popping up in like Denmark and like Taiwan and
like Armenia.
Speaker 3 (30:44):
Does having worked on this project make you look forward
to rainy days? Like do you sit on benches waiting
for people to interact.
Speaker 1 (30:50):
With the art?
Speaker 3 (30:51):
Oh?
Speaker 5 (30:51):
Absolutely. It has completely changed our perspective on rainy days.
And one of our favorite things to hear when we
tell people about this 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.
Speaker 6 (31:09):
That's so we become so hyper sensitive to it that
every time it starts to rain or like the forecast
predictions range, like we're like on the edge of our sets,
like we're preparing. We're making our whole work agital depends
on the weather, for sure.
Speaker 1 (31:24):
Well, tell us a little bit about your connection with
the Awesome Foundation.
Speaker 4 (31:29):
Sure.
Speaker 5 (31:29):
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 Autome Foundation. If anyone doesn't know,
the Awesome Foundation is an organization that every month it's
(31:54):
one thousand dollars to the person with a cool idea
or an awesome idea, as they put its attached. So
I submitted this rain activated our idea but were not
called rainworks to the Austin Foundation, and they accepted it,
and that was what really gave it the first push.
Speaker 2 (32:11):
All right, Well, I thought, uh, 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?
Speaker 1 (32:18):
With a Peregrine and zach Vi.
Speaker 3 (32:19):
It's called.
Speaker 2 (32:22):
All right, we love your Rainy Day project, and we
figured we'd give you a quiz where all the answers
involve rain.
Speaker 1 (32:27):
And you can work together on this. So you guys ready, okay,
you ready?
Speaker 6 (32:31):
All right?
Speaker 1 (32:33):
I got five questions for you, all right.
Speaker 2 (32:34):
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?
Speaker 6 (32:44):
Singing in the rain? Yea for one?
Speaker 1 (32:46):
Number two.
Speaker 2 (32:48):
Prince's manager questioned the decision to put When Doves Cry
in this movie slash album because the song didn't have
a bassline and he didn't think it would be a hit.
Speaker 1 (32:56):
What Prince movie are we talking about? Yes?
Speaker 3 (33:01):
All right?
Speaker 1 (33:01):
Number three?
Speaker 5 (33:02):
All these culture references and depending on your action, he's really.
Speaker 1 (33:07):
Pulling through, all right. Number three.
Speaker 2 (33:10):
During the filming of this award winning movie, both Tom
Cruise and Dustin Hoffman thought the flick would be a clunker.
Speaker 1 (33:16):
The whole time.
Speaker 2 (33:17):
They referred to it as two schmucks in a car.
What movie are we talking about?
Speaker 1 (33:23):
Wait?
Speaker 5 (33:23):
I got this one, Raymond?
Speaker 1 (33:25):
All right with the big answer, here we go. Number four.
Speaker 2 (33:31):
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
Schaeffer and performed by the Weather Girls, was intended to
be a gay ant to, much like y mc A.
(33:53):
You know the name of the song.
Speaker 5 (33:54):
It's men.
Speaker 1 (33:55):
Yes, all right, how did they do?
Speaker 3 (33:58):
Mango als went 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.
Speaker 1 (34:09):
Thanks so much for them. Yeah, that's awesome, guys, that'd
be great.
Speaker 3 (34:16):
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.
Speaker 6 (34:24):
For having us.
Speaker 3 (34:37):
Okay, well, so we talked about fictional invisibility cloaks as
well as the closest things we have to real life ones.
But there's one more thing I want to talk about,
and it's the psychological.
Speaker 1 (34:45):
Sort kind of a psychological invisibility quote. I don't even
know how that would work.
Speaker 2 (34:50):
Is it like a helmet that would block your brain
waves or something like that?
Speaker 3 (34:53):
Yeah, that's a good guess. But no, nothing like that.
I'm actually talking about the great study I came across
about a No, I'm gonna called it invisibility cloak illusion,
and that's the name researchers that Yale University came up
with for our mistake and belief that we observe others
way more than others observe us.
Speaker 2 (35:09):
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 out grocery shopping or walking our dogs.
Speaker 3 (35:18):
Or something like that, exactly pretty much anytime 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 fail 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
(35:41):
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.
Speaker 1 (35:48):
It's pretty wild.
Speaker 2 (35:49):
I mean, we feel like we're invisible when the fact
that we observe others should tell us.
Speaker 1 (35:53):
Just the opposite of this.
Speaker 2 (35:55):
And I really can't understand why we make this silly mistake,
because it just that we're ego main and you know,
we think we're the observant person and the only observant
person in a room.
Speaker 3 (36:04):
Yeah, that's definitely part of it. But at least there's
a good reason why we think that way.
Speaker 1 (36:08):
And why is that?
Speaker 3 (36:09):
Well, the researchers at 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.
Speaker 2 (36:18):
All right, so we've secretly scoped out the competition at
a job interview or a glance around the waiting room
in a doctor's office, and just in case we.
Speaker 1 (36:25):
Need an alibi, we have a magazine or something like that.
Speaker 2 (36:28):
It's funny that we all assume we're the only ones
who do this, though.
Speaker 3 (36:32):
Right, so, when it's actually so widespread of 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.
Speaker 2 (36:48):
That sounds exactly right, and it actually makes me think
of 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.
Speaker 3 (37:04):
So the study was what scientists rounded up a bunch
of toddlers and had this epic peekaboo session.
Speaker 1 (37:09):
Not exactly but but kind of.
Speaker 2 (37:12):
So the researchers at the University of Cambridge had a
group of three and four year olds wear imasks, 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 theirs,
and unsurprisingly, nearly all the kids said they were hidden
from view while their eyes were covered, and most of
(37:34):
them actually thought the ie mask.
Speaker 3 (37:35):
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.
Speaker 2 (37:43):
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 at all in.
Speaker 3 (38:00):
The way way. So they admitted their bodies could still
be seen even when their eyes were covered. So what
do they mean by invisible?
Speaker 2 (38:06):
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.
Speaker 3 (38:21):
See me, which is pretty existential.
Speaker 1 (38:25):
Yeah, I know, I know.
Speaker 2 (38:26):
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 suggest
that perception might be something we only adopt or maybe
decide on later in life.
Speaker 3 (38:46):
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 visible.
Speaker 2 (39:00):
All right, well, Mango, you need to keep those eyes open,
because there's only one thing you can't hide from the.
Speaker 7 (39:05):
PGG fact off exactly.
Speaker 1 (39:18):
All right, here's something I hadn't thought about.
Speaker 2 (39:20):
Any light beam 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 and
a jet dodging those rays, none of that's possible.
Speaker 3 (39:31):
You know that some of the things you see in movies,
you just ruined all movies I 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 Dummer probably did more for the early university in
terms of securing funds and building its reputation. The problem is,
Dummer College isn't a great name.
Speaker 2 (39:51):
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. His 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
(40:12):
all the snow around it.
Speaker 3 (40:14):
So despite all the safety features and cars with backup
cameras and beeping sensors, people still back up into lamposts.
So researchers at Kyo University in Japan have come up
with back seats that actually turn 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
(40:34):
making the children sitting in those seats disappear as another matter.
Speaker 1 (40:37):
Definitely, all right, here's a fun one about not being seen.
Speaker 2 (40:40):
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.
Speaker 3 (40:52):
In two thousand and six, Magician David Copperfield and his
two assistants were walking down the street when muggers approached
and demanded all their money. And while the assistants forked
over plane tickets, cell phones, and over five hundred dollars
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 wowed the officers,
(41:12):
showing them he actually had a passport and loss of
cash on him the whole time. I want to I
know he's such a performer, but he did help catch
the bad guys and I kind of love it all right.
Speaker 2 (41:23):
Well, in that case, I'm going to have to give
you today's championship belt.
Speaker 1 (41:26):
So that's it for today's episode.
Speaker 7 (41:28):
Thanks so much for listening.
Speaker 1 (41:43):
Thanks again for listening.
Speaker 2 (41:44):
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.
Speaker 3 (41:51):
Christa McNeil does the editing thing.
Speaker 2 (41:53):
Noel Brown made the theme song and does the mixy
mixy sound thing carry Roland does the exec producer thing.
Gave blues you or our lead researcher, with support from
the Research Army including Austin Thompson, Nolan Brown and Lucas Adams.
Speaker 3 (42:05):
And Eves Jefcok gets the show to your ears. Good job, Eves.
Speaker 2 (42:08):
If you like what you heard, we hope you'll subscribe,
and if you really really like what you've heard, maybe
you could leave.
Speaker 1 (42:12):
A good review for us.
Speaker 3 (42:13):
Do we forget Jason?
Speaker 1 (42:15):
Jason who
Part-Time Genius News
Hosts And Creators
Will Pearson
Mangesh Hattikudur
Popular Podcasts
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Crime Junkie
Does hearing about a true crime case always leave you scouring the internet for the truth behind the story? Dive into your next mystery with Crime Junkie. Every Monday, join your host Ashley Flowers as she unravels all the details of infamous and underreported true crime cases with her best friend Brit Prawat. From cold cases to missing persons and heroes in our community who seek justice, Crime Junkie is your destination for theories and stories you won’t hear anywhere else. Whether you're a seasoned true crime enthusiast or new to the genre, you'll find yourself on the edge of your seat awaiting a new episode every Monday. If you can never get enough true crime... Congratulations, you’ve found your people. Follow to join a community of Crime Junkies! Crime Junkie is presented by Audiochuck Media Company.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com