September 1, 2017 • 42 mins
Sure, invisibility is about Harry Potter cloaks and invisible inks. But it’s so much more than that, too! From the way butterflies see a secret world of light that humans can’t, to the 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.
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Speaker 1 (00:00):
Guess what, mango, what's that? Will? I was reading this
whole story about a bank robbery that happened in 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
(00:21):
thing is when the cops come fromm he was totally baffled. Well,
he kept saying, I was wearing the juice. The juice, Well,
apparently he poured lemon juice all over his face because
he knew it could be used as this invisible ink
for writing. And the poor guy, he was really bewildered
because he said he tested it out, and the cops
pressed him for details, and he said the lemon juice
(00:42):
had gotten in his eyes the first time when he
poured it all over his face, and then he took
a selfie to see if it had worked. And the
combination of squinting and not being accustomed to taking his
own photo, I mean, this this was well, it made
him take a photograph that he wasn't in and he
just believed that he was invisible. I know you almost
feel bad for the guy, but you know, reading up
(01:04):
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,
(01:36):
welcome to Part Time Genius. I'm Will Pearson and as
always I'm joined by my good friend Man Guesh, I'll
Ticketer and over there on the other side of the
glass with the biggest smile that you can't see is
Tristan McNeil, our producer, And on today's show, we're taking
a WorldWind tour of our invisible world and trying to
get a better grasp of all things unseen. You know,
the idea of invisibility is fascinated mankind for thousands of years.
(01:57):
It's parts of our myths and our folklore and pop
culture and even our psychology. Of course, there are lots
of different kinds of invisibility, so this will be a
super fun Hodgepodge episode where we cover as much as possible.
We'll talk to a couple of insightful authors who have
devoted years of study to stuff we can't see. So
who do we have on the line today, Mango, Today
(02:17):
we're talking to Bob Berman, one of America's top astronomy
writers and author of a brand new book about the
curious history of invisible light. It's called Zapped, and it's
incredible and we'll have some wonderful quizzes along the way
as usual. All right, So, in honor of Bob's new book,
I want to dive straight into the science and talk
about light, and more specifically invisible light. You know, obviously
there are large portions of the electromagnetic spectrum that we
(02:39):
have no trouble observing, but there's also a huge part
that's totally invisible to us. That's the part that includes
things like ultra violet light and for red light, radio waves, microwaves,
X rays, gamma raves, you know, all that good stuff. Yeah.
I mean, I always knew there were parts of the
spectrum beyond our range of vision, just like you know
there's sounds outside the limits of human hearing. But reading
(03:00):
Bob's book put the vastness of light in a completely
new perspective for me, and it really blew me away.
So Burman rights, there's more light in the universe than
anything else. So if you were to add up every
individual light photon in the cosmos, they would account for
nine point of everything there is. And those forms of
invisible light you listed off, that actually makes up the
(03:22):
vast majority of the light. I actually can't wrap my
head around that fact that it seems unbelievable, but you know,
our eyes are designed to recognize only the Sun's most
abundant energy, so we really can only see the colors
that the Sun emits most strongly. And even though the
whole universe is light, the bulk of it, it's completely
invisible to us. We've actually figured out all kinds of
(03:43):
ingenious ways to measure and observe forms of invisible light.
And one of the most interesting things I came across
while prepping for this episode was the way human observation
actually affects the behavior of light. All right, well, I
think this is pretty complicated, so why don't you break
it down a little. Well. When quantum theory became all
the rage in the twentieth century, scientists started noticing something
super weird. They found that when they use special equipment
(04:05):
to pinpoint the location of photons, these tiny bits of
matter always behaved as particles. For example, they could pass
through one tiny hole or another in a barrier, but
not through both holes at once. All right, so far,
so good, and particles do what particles do that. I
don't think there's anything weird about that, right, But the
scientists also discovered that when they didn't try to determine
the exact location of each photon, the photons behaved as
(04:28):
waves instead of particles. So the photons were then able
to pass through both tiny holes in a barrier at
the same time. And that's something that only waves can do,
not particles. Okay, alright, I spoke through soon. That's really weird.
And so you're saying that light, photons and other sub
atomic matter act like particles, you know, when they know
we're watching, and then like waves when they know we
aren't looking. Yeah, it's something like that. So obviously the
(04:51):
photons themselves aren't aware of us watching them, but they
definitely seem to act differently based on how closely we
observe them. And the best explanation, at least according to
most physicists, is that when we look closely, our brains
halt the wave pattern so that we can see the
photon in a certain place as a particle. It just
makes us feel better that way. That's really insane, all right,
So where does that leave us? Does light exists as
(05:13):
a wave or as tiny bits of almost invisible matter? Yeah,
it's both. So Bob Berman sums up the paradox this way,
and I'm going to quote him here. He says, just
a century ago, the local realism mindset of science and
even common sense held that all objects, including atoms and photons,
have an existence independent of our observation of them. But
(05:33):
that's been replaced by a more modern view that our
observation itself is necessary for the very existence of a
photon or an electron. A spooky prospect, no kidding. Yeah,
So he continues, it possessed no real existence as an
actual photon or electron or whatever it was. Rather, it's
observed existence is it's only existence. The observation establishes reality,
(05:54):
nothing else is certain. That's pretty trippy. Yeah, the stuff
feels so philosophical, and especially when you go from a
micro perspective to a macro one, because just like with photons,
the color and brightness of light doesn't exist outside the
experience of the observer. We only see light as a
certain color because of how it stimulates the cones in
our eyes and how our brain interprets those signals. Well,
(06:16):
that's a good point, but it's also kind of a
terrifying mean. It means the external world is really just
as invisible as a UV ray, because outside of human observation,
there is no color or brightness. It's just this mix
of different invisible energy pulses. Actually, by the way, that
this is off topic, but did you read about the
women that supposedly have four cones in their eyes instead
(06:36):
of three, and as a result, they can see hundreds
of millions of color. That's a wild Yeah, they're called tetrachromats.
But baby, we're clinging too tightly to the human experience.
And you know, I actually did some digging to see
if there were any animals whose vision best ours in
terms of light perception, and it turns out there quite
a few that put the invisible spectrum to pretty good use. Awesome,
(06:57):
So give me the load down. Well, one case where
plenty of animals have a speed is the ability to
perceive ultra violet light. Invisible UV radiation is all around us.
And while it's useful for getting a golden tan, it's
also a menace because exposure to it can lead to
melanoma and other illnesses. But that hasn't stopped some animals
from making the most of UV light. There's some species
(07:18):
of birds that have plumage that you know, to our
eyes look the same between males and females. But if
your vision allows you to see the UV range like
those birds are able to see it, you know you'd
be able to make out the uvy markings that distinguish them.
So those markings make it easier for the birds to
find a meh definitely, but that's actually only part of it.
Some other birds determine which chicks to feed based on
(07:39):
how much UV light you know their heads reflect. For
whatever reason, the heartier birds tend to have a shinier
crest than their weaker siblings, so when the mama bird
has limited food to share, she'll go with whomever has
the most shine. There's also the fact that urine and
feces of mice and other small prey are visible in
the ultraviolet range, so birds that are sensitive to UV
light can use these traces to track their prey even
(08:02):
in a place where everything is uniform in color, you know,
like a green field or something like that. But you know,
birds aren't the only ones that can do this. You
have rodents and bats and even some marsupials that can
see UV light for similar reasons. So I actually think
I read something about butterflies also having great ev perception,
and I think they use it to identify which flowers
are currently producing nectar based on the color of the
(08:25):
petals or something. Well, yeah, I'm glad you mentioned that,
because butterflies with a high sensitivity light are often considered
to have the widest visual range of any form of wildlife.
It's crazy the invisible world might be the most visible
to butterflies of all things. But before we move on,
there's one last animal I want to talk about, and
that's the reindeer. So I'm sure there's a Rudolph joke
(08:47):
in here somewhere, but not telling reindeer can see ev risk. Well,
it sounds strange at first, but reindeer of evolved to
take full advantage of the ultraviolet range. And they're not
the only ones. There are other Arctic mammals who make
their home at the Earth's polls, and they have to
deal with much higher levels of UV light. Yeah, the
thinning ozone layer doesn't block as many rays as it
used to, especially in those upper latitudes. Yeah, exactly. So
(09:10):
there was this study of the University College of London
and the University of Tromso in Norway, and they found
evidence that not only a reindeer resistant eye damage from
intense UV rays, they're also able to see UV light
and this helps them find food and avoid predators. And
in the winter, reindeer primarily do two things. They eat
lichen and they try to avoid being eaten by wolves.
(09:31):
And wouldn't you know it, lichen and the fur of
wolves both absorb UV light. So because snowy landscape strongly
have reflect UV rays, you got reindeer that can spot
lichen and wolves with ease. Yeah. That's really cool, And well,
I think you and I could nerd out on reindeer
facts for a while, Like how Norwegian scientists wanted to
get closer to reindeers so they could study them better,
(09:52):
So they wore polar bear costumes and did that work. No,
not at all, like it's scared off the reindeer. But
they also wrote a scientific paper on reindeers reactions to costumes,
and we're hoping to redo the study with better costumes,
like like a clown costume. I like how they just
went off track there, Like that didn't work, So let's
just do costumes. How about clowns? How about police officers?
(10:12):
Science is great, but what I was saying was I
think we should shift the topic a little. All right, well,
what do you what do you want to talk about?
Secret messages? So last year a group of scientists and
friends developed a special kind of paper that can carry
secret messages. It looks just like plain old paper, but
you can use different wavelengths of UV light to read, write,
or even erase the messages that can't be seen invisible light.
(10:33):
So how does that work? So apparently the paper has
this special kind of molecule bonded to its cellulose fibers
that reacts and turns fluorescent when exposed to UV light.
The idea is you can write messages on the paper
using a stencil to produce dark and bright areas that
react differently under the UV lamp. But the really cool
thing is that the process is completely reversible. You can
(10:54):
expose the used paper to a shorter wavelength of UV
light that erases the message completely, and that way of
paper can be used over and over. I mean, it
is kind of cool, but what's the advantage over you know,
the disappearing reappearing and visible length that our kids play
with and stuff like that. So why is this better
than that? So not only are the messages on this
paper undetectable under visible light, they also can't be dissolved
(11:16):
with other chemicals. So it's the super useful tool in
anti counterfeiting and tracking operations. A good job, France, you know.
I actually want to dive into some of the historical
obsession with invisibility and the ridiculous potions humans used to make.
But before we do that, how about we check in
with Bob Burman and see if he can tell us
a little about the cool properties of light and how
humans have managed to turn something invisible to our advantage.
(11:42):
So in this episode on All Things Invisible, we've been
talking a little bit about this great book, Zapped, and
we're really lucky to have one America's top astronomy writers
on with us and the author of this book. It's
Zapped From infrared to X rays, The Curious History of
invisible Light. Bob Berman, Welcome to part time genius. Thank
you great to be here. All right, well let's just
start with the basics. So can you explain to us
(12:04):
where light comes from. Well, all lights, except for gamma rays,
comes from one source only, and that is atoms. If
the atomy gets excited in any way, electricity, collisions, anything
can may be excited, madam, so that the electrons are
In the case of hydraten, it's only got one electron
jumps to a higher orbit because it's excited. It really
(12:28):
doesn't like to be there. So in a fraction of
the second, it'll tumble down closer to its nucleus, and
that is what causes any kind of light. And the
distance that it tumbles down determines the color of the
light and therefore whether it's visible or invisible. So I
know you talk about this in your book, but what
(12:49):
did ancient people think about light? And were they aware
of invisible light? They felt about light as at first
something that comes from the eye, and then later on
as an interaction between a beam from the eye and
external objects. So they got it wrong for a long time.
They realized that it involves something very fast speed, but
(13:13):
nothing more than that, and nobody foresaw invisible light until
the time of the Renaissance of the Middle Ages. It
was one of those things that no wise person or
Greek philosopher, or scientists or religious order, nobody came up
with the idea that there might be kinds of light
(13:34):
out there that our eyes can't see well. In the Renaissance,
as you mentioned, you know, with this idea of invisible
light being a possibility, how did this start to be discovered? Well,
it's really William Herschel who found the first kind. He
projected sunlight through a prism piece of cut glass onto
a tabletop, so you had the whole rainbow of colors.
(13:56):
And then he put a thermometer in each color, and
he had other themometers on the side in the darkness
to act as controls. And so he noticed that when
the thermometer was in the blue or the green part
of the spectrum, the temperature went up very little. In
the yellow and went up more, and the red they
went up still more. But then he took a break,
(14:17):
and when he came back some minutes later, the sun
had moved across the sky, so the spectrum on the
table had shifted, and now his thermometer on the table
was no longer in the visible light instead of was
sitting in a spot of darkness outside of the spectrum,
just beyond the red end of the spectrum. And he
(14:37):
looked down on it, and now the thermometer was crazy.
Who had it was registering much more heat than any
color did. And so he repeated this and he realized
that the blank spot beyond the red part of the
spectrum was heat, was producing more heat. Well, he realized
(14:58):
it had to be an invisible kind of light that
was creating the heat. And he called these calorific rays.
Later on we came to call it infrared. So that
was the first kind of invisible light ever discovered. Wow. Wow.
And you also talked in the book about the discovery
of of X rays and I'm curious what the you know,
(15:18):
the public response was to this discovery. Well, X rays, Yeah,
that changed the world too. That was Renkin, and he
was boy. He had fame, and he would have had
fortune too if he had patented it, but he didn't.
Generously just allowed the world to use it, and almost
right away people realized the value in medicine that you
(15:41):
could use X rays and find a bullet wear a
bullet was my body for someone who had been shot
or were broken, bones were broken, And but nobody knew
at the time that X rays also had a dark side,
that it could produce harm as well as benefits. What
new opportunities for the use of invisible light are the
horizon and things like medicine or technology or culture, well
(16:04):
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 when we're on a camping trip, or use our
cell phones, those are all parts of the radio spectrum.
And then we know about the infrared. We use heat labs,
we use garage door openers, that are they're using infrared
and ultra violet. That's boy, that's the one with the
two edged sword. Ultra violet is both the most dangerous
(16:49):
form and the most valuable for our health. And what
makes UV rays so harmful to us, Well, they're the
beginning of the part of the spectrum that has the
power to ionize and others to strip electrons from adams
and therefore to change genes, to change chromosomes, to alter DNA,
(17:10):
and that could give rise to cancer, and it does
the eight thousand or so melanoma deaths per year. Skin
cancer are caused by generally too much UV, usually from
from from a bad sudden burn in our youth. And uh,
and that's why people nowadays know that they should be
(17:33):
putting on sunscreen and wearing hats and stuff like that.
But bad thing has happened from that too, in that
we've now blocked so much of the UV. That's strange
things are happening to our bodies that that most even
doctors are not aware of, although many are like like,
(17:53):
like what you do have some examples of this? Yeah, yeah,
and this has started. If I could give just a
bit of background, There was a time, of course, when
we were an agricultural society and we were out of
doors a lot, and we got plenty of sunlight and
therefore plenty of ultravolet, which is a few percent of
the sunlight and stimulates our bodies to produce U V
(18:17):
a vitamin D very quickly. That UV induced vitamin D
is such a avalanchingly fast process that we get more
U V from twenty minutes in the strong sunlight then
you would from drinking two hundred glasses of milk. So
somehow our bodies want lots of vitamin D production from UV.
(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
worst of all, this is something that they 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 of
of mold people where we're blocking the sun entirely and
not getting enough sunlight. They see it that it wasn't
that many decades ago. The kids after school. Of course,
(19:24):
during school they're not getting any UV and therefore not
producing any vitamin D. But after school kids used to
play outdoors and parents used to say, yeah, come back
at dinner time, and between they'd be out doing whatever
in the playground or climbing trees, and then that changed,
so their UV levels in their and their blood has
(19:44):
dropped to really, really low levels. So what does this
do is turns out that u V is one of
the strongest prevent ers of cancer. It stops cancers from growing,
so when they're tiny, pre detectable tumors, they don't get
any bigger. This year, for example, it was found that
(20:05):
pancreatic cancer is prevented by by adequate vitamin D triggered
by ultra violet light. So there are a lot of
health benefits also psychological benefits in terms of treatment for
depression and and things like that. If you get enough
(20:27):
sunlight induced h vitamin D, it's hard to strike that
strike that perfect balance. Now you're so right. At the
same time, you don't want to burn. So the people
like Dr Canell in the Vitamin D Council, they say
that we should get as much sun as we can
without burning, because everybody is so different and how much
(20:53):
sun they can handle before they start to burn. You know,
blue eyed, blonde people tend to burn fast, and camp
shouldn't get as much. Well, there are a thousand other
questions we could ask. This such a fascinating book. I
hope all of our listeners will check out zapp. But Bob,
thanks so much for joining us on Part Time Genius.
It's been a pleasure. Thanks so much. You're listening to
(21:27):
Part Time Genius and we're talking about the peculiar allure
of turning invisible, So mego. We mentioned at the top
of the show that humans have been obsessed with the
idea of invisibility from millennia, so I thought it might
be fun to take a look at some of the
weirdest attempts to go invisible that people have tried all
over the years. Yeah, so I'm definitely game. I spent
some time looking up medieval recipes and spells to turn
(21:47):
yourself invisible, and as you might guess, they're insane. So
one of my favorites is from the Ashmole, which is
this anonymous fifteenth century manuscript that collected over a hundred
eighty magical and magical recipes in English and Latin. So
this is the invisibility spell. It goes, if you wish
to be invisible, take a dead dog and bury it,
(22:08):
and plant a bean plant over it, and place one
in your mouth, and without a doubt you'll be invisible.
That that's it. It's simple. It's like one of these
great invisibility life hacks. But but don't worry. If you're
fresh out of dead dogs or beans, there's another suggestion
for you. Um this is also from the Middle Ages.
Grind up an owl's eye with the ball of beetle
(22:29):
dung and some olive oil and rub it all over
your body. I like the addition of the olive oil,
like weird stuff, and you just put some olive oil
in there that I think I'd rather eat the dead
dog being So why do they all have to be
so gross? So most invisibility charms that ties to a
cult practices so they tend to feature nasty ingredients like
the ivan a for a heart of a bat or whatever.
And one of them actually calls for the head of
(22:50):
someone who committed suicide, but stuffed with fava beans. God,
it's hard to imagine why any of these ingredients were
picked to be the ones that would turn you invisible,
But I don't know, and think about it. Might have
something to do with our desire for power, which seems
to be at the root of man's continuing quest for invisibility.
I mean, we have stories going all the way back
to antiquity that point to the dark side of going invisible. Yeah,
(23:12):
so there are all kinds of myths and folk legends
that warn about the corrupting power invisibility and how it
can lead even the most pure of heart heroes into
recklessness or voyeurism. And well, you know, these commonalities between
fables from different cultures. I find these fascinating. In this case.
They seem to suggest that we all know invisibility as
a power that we probably shouldn't have, and you know,
(23:34):
it doesn't stop us from wanting it though. And in fact,
the top two superpowers that people always cite is the
ones they'd most like to have, are the ability to
fly and the power to turn invisible. Yeah. So both
of those provide the user a crazy amount of freedom,
and maybe that's why we find them appealing. You know,
that could definitely be the case. But in keeping with
the shady side of invisibility we've been talking about that
(23:55):
there might be another explanation. And I couldn't find an
actual psychological study of this, but there is some speculation
about what the choice between flight and invisibility says about
a person. William Barry was this psychotherapist and professor at
Florida International University. He suggests that people who opt to
go invisible are embracing their dark side, you know, the
(24:15):
side of themselves that they typically don't like to acknowledge
as being part of them. So this is the side
of your psyche where all your most shameful thoughts and
desires dwell. According to Barry, quote many of those who
choose invisibility do so to hear what others say about
them when they aren't around, or to spy on others,
or to procure things that they don't have the money
to pay for. It's easy to see how this relates
(24:37):
to the dark side. Yeah, it really is, especially when
you compare it to choosing flight, which is mostly appealing
as this form of fast travel or experiencing this different sensation,
but it doesn't seem to have any of the darker edge,
right And you know, Barry found that people who choose
power of flight generally see it as a way to
add excitement or fulfillment to their lives, whether that's from
you know, maybe rescuing people from burning buildings or just
(24:59):
zipping across the world to have dinner in Italy or
you know, something like that, which is interesting. You know,
there's another commonality between invisibility fables that we should probably
talk about, all right, and what's that invisibility cloaks. So
ancient Greek myths described caps and cloaks with magical properties
that made the were invisible to other mortal men, and
from their invisibility, cloaks have popped up in everything from
(25:21):
Welsh and Germanic folklore to modern day pop culture. Of course,
and I'm guessing being a big fan, you think of
Harry Potter definitely, so Harry Potter is never far from
my mind. But scientists have been hard at work on
cloaking devices for a while now, things that can mask
or completely hide an object or a person from sight.
And sometimes they're more successful than others, but all of
(25:42):
the most promising ones involved something called meta materials, and
it's just you know, some kind of super science cloth
or something more or less. So meta materials are basically
a kind of material that's engineered to have properties that
that don't occur in nature, and in this case, it's
a light bending property that manipulates the eye. So the
reason objects are visible to our eyes at all is
(26:03):
because objects distort light waves based on their shapes. But
when the light from an object reaches our eyes, we
see the object by recognizing those distortions. Alright, so meta
materials they somehow counteract this or so. The idea is
that the meta material forms a kind of shell around
the object, or a cloak, so the light rays bends
smoothly around the meta material and recombined on the other side.
(26:26):
And one helpful example I came across is that it's
kind of like water flowing around a rock and a stream.
I viewer on the far side wouldn't see anything unusual,
but both the meta materials shield and object in its
center would be completely invisible to him. It would look
like the lights bouncing off a smooth surface, which is
pretty cool. But I don't know. I have the say,
I've read so many headlines over the last few years
(26:48):
that claim we're this much closer to Harry Potter like
invisibility cloak. And you know, there are definitely some similarities
to what you're describing, but it's hardly a one to
one I mean, I mean, natural materials get their special
properties from the arrangement of atoms and there's no way
what's going on with these meta materials is the same thing. Yeah,
that's true, And these cloaking devices are more like chunky
(27:09):
rings and pyramids that fit over a stationary object right now,
rather than any sort of sleek piece of fabric. But
the technology is advancing pretty quickly. Well, I'm glad to
know that we're on our way towards that. But why
don't we break for a little quiz? Alright, So today's
show us about invisibility. We decided to bring on to
(27:31):
Seattle based artists who produced the delightful art series that
only shows up when it rains. Welcome to the show,
Peregon Church and Zach Fisher. Thank you great to be here.
I am so excited to have you on. And and
for you listeners who aren't familiar with rain Works, you
should definitely check out the photo gallery at www dot
rain dot works because it's fantastic. So can you tell
(27:53):
us a little bit about how you came up with
this idea of making invisible artwork that only shows up
in the rain. I love thinking of ways to use
materials that already exist in ways that they shouldn't be used.
And I came across this stuff called super hydrophobic coatings. Basically,
when you put it on the surface, he keeps it
from getting wet. And I thought, wow, that's super cool.
(28:16):
You're watching all this water roll off these clothes and
shoes and whatever. What if you put it on something
that changed color when it got wet, like concrete and
so you since it's a spray on the thing, you
could spray it through a stencil on the concrete and
as long as it was invisible and dry, you can
create art that was only visible when the surface is wet.
Would you tell our listeners a little bit about some
(28:36):
of the designs you do and how you make them interactive? Sure,
we like to do things that are positive, things that
don't make someone stay better. That's are really one of
the big motivations behind it. Because in Seattle and the
Pacific Northwestern general, people tend to suffer from sad seasonal
effect of disorder. The skies are gray and it's dreary
(28:56):
and wet all the time. So we figured we could
take that thing that causes the juriess the rain and
use it to make people smile. We did a lock
nest monster at a at a dock out in over
a lake here in Seattle Green Lake so that people
could stumble upon the monster while they were out on
rainy days. We do games. Sometimes you've done like it
(29:18):
Don't Touch the Lava game. Um, We've done like nostalgic
references to like characters that we love as like when
we were kids. So like we've done like a Peter
Pan rainwork, and like the Calvin and Hobbs rain work.
Basically just whatever we think would like cheer someone up
or make them smile or make them think when they
see it it's funny. I mean even hearing the examples
(29:40):
makes you smile. That's pretty great. And you've now turned
this into a business. So what are the best applications
of your rain works? And you know that you've seen
in the wild now, oh man, we've seen so many
from all over the world. Some people have done like
promposals or actual wedding proposals with them. We've seen people
use public sountains to make like dolphins that appear. Yeah,
(30:05):
there's one just like a day or two ago where
they coated a canvas with it and through water balloons
with like water based paint in them, through do a
gender reveal. Right back that was what that was. Yeah, Yeah,
that kind of works a little differently because our spray
doesn't repel paint, but it like reacted with it in
a certain way, so it does kind of make the
(30:25):
letters pop, but like not in the way you expect.
It's really interesting to see like a new application for it,
and that's really been the coolest thing is like just
since this started, it's really taken off just all around
the world, and we get like new one's popping up
in like Denmark and like Taiwan and like Armenia. Does
having worked on this project make you look forward to
(30:47):
rainy days? Like do you sit on benches waiting for
people to interact with the art? Oh? Absolutely. It has
completely changed our perspective on rainy days. And one of
our favorite things to hear when we tell people about
project is them the words coming out of their mouths,
oh my gosh, I can't wait till it rains now,
Like that means the world to us. We become so
(31:10):
hyper sensitive to it that every time it starts to
rain or like the forecast predicts range, like we're like
on the edge of our chieves, like we're preparing, we're
making work, our our whole work as well, depends on
the weather. For sure. We'll tell us a little bit
about your connection with the Awesome Foundation. Sure. When I
(31:30):
had this idea, it was just an idea, like on
a note in my phone for a long time, but
it was one of one of my favorites, and I
started mentioning it to people and eventually mentioned it to
a friend in Seattle who was part of the Seattle
chapter of the Awesome Foundation. For anyone doesn't know, the
Awesome Foundation is an organization that every month it's one
(31:54):
dollars the person with a cool idea or an awesome idea,
as they put it, No, it's things attached. So I
submitted this rain activated our idea, but we're not called
rain works do the Austin Foundation, And they accepted it,
and that was what really gave it the first push.
All right, well, I thought we should play a little
game with these guys, and Mango, you came up with
(32:16):
one that's appropriate from what what game are we playing
with a Peregrine and Zach, it's called I'm Only have
you in it rains? All right, we love your rainy
Day project, and we figured we'd give you a quiz
where all the answers involved rain and you can work
together on this. So you guys, ready, ready, alright? He
got five questions for you, all right. Number one, Gene
Kelly had a one hundred and three degree fever when
(32:38):
he danced the big number in this rainy movie. What
classic film are we talking about? For one? Number two,
Prince's manager questioned the decision to put When Doves Cry
and this movie slash album because the song didn't have
a baseline and he didn't think it would be a hit.
What Prince movie are we talking about? Purple? Yes? Alright?
(33:01):
Number three? All these culture references and depending on yours action,
he's really pulling through alright. Number three. During the filming
of this award winning movie, both Tom Cruise and Dustin
Hoffman thought the flick would be a clunker. The whole time.
They referred to it as two schmucks in a car.
What movie are we talking about? Wait? I got this one, Ramon,
(33:25):
alright with the big answer, here we go. Number four.
Before this actor won the role of Dwight Shrut on
the office seth Rogan had auditioned for the role. Who
are we talking about? Wilson? Yes, they both got that one,
all right. The last question see if you can get
the perfect score number five. This song, written by Paul
(33:46):
Shaffer and performed by the Weather Girls, was intended to
be a gay anthe much like Y M c A.
You know the name of the song, It's rain Man. Yes, alright.
How did they do a mango our ols when astounding
five for five, which means we'll be sending them our
top prize, a handwritten note to their mom or boss
singing their praises congratulations, m thanks so much. Yeah, that's awesome. Listeners,
(34:16):
please check out rain dot works when you get a second,
and thank you guys so much for all the work
you do and for putting smiles on so many faces
having us. Okay, well, so we talked about fictional invisibility
(34:39):
cloaks as well as the closest things we have two
real life ones. But there's one more thing I want
to talk about, and it's the psychological sort kind of
a psychological invisibility quote. I don't even know how that
would work. Is like a helmet that would block your
brain waves or something like that. Yeah that's a good guess,
but no, nothing like that. I'm actually talking about the
great study I came across about a nomena called it
(35:00):
invisibility cloak illusion, and that's the name researchers at Yale
University came up with for our mistaken belief that we
observe others way more than others observe us. All Right,
so this is kind of like us pretending that maybe
we're under invisibility cloaks when we're out in public, if
we're grocery shopping or walking our dogs or something like that,
exactly pretty much any time we're in public, really, So
(35:21):
the team describes it this way, and they're abstract. Quote,
whether at a coffee shop, in a waiting room, or
riding the bus, people frequently observe the other people around them,
Yet they failed to realize how much other people engage
in the same behavior, and that they therefore also are
being observed. Because it's logically impossible that people, on average
(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 that's pretty wild. I mean,
we feel like we're invisible when the fact that we
observe others should tell us just the opposite. Of this,
And I really can't understand why we make this silly mistake,
because it's just that we're egoman acts, and you know,
we think we're the observant person and the only observant
(36:03):
person in the room. Yeah, that's definitely part of it.
But at least there's a good reason why we think
that way. And why is that? Well, the researchers that
Yale concluded that social norms compel our neighbors to pretend
to be busy with something else if it looks like
we might catch them watching us. All right, so we've
secretly scoped out the competition at a job interview, or
a glance around the waiting room and a doctor's office,
(36:24):
and you know, just in case we need an alibi,
we have a magazine or something like that. It's funny
that we all assume we're the only ones who do this, though, Right,
so when it's actually so widespread and phenomena that it
even has its own name, researchers call it civil and attention.
I kind of like that. Yeah, But my favorite part
of the study is this line from the conclusion, however
irresistible the sensation of being invisible, maybe it is not
(36:47):
to be trusted. That sounds exactly right, and it actually
makes it me think of this this other study I
read on the logic of the game Peekaboo. Apparently it's
this great display of the kind of nonsensical logic that
most kids share, namely the idea that you can make
yourself invisible by just covering your own eyes. So the
study was what like scientists rounded up a bunch of
toddlers and had this epic peekaboo session, Not exactly, but
(37:10):
but kind of. So the researchers at the University of
Cambridge had a group of three and four year olds
where I'm asked, and then they asked them whether they
could be seen by researchers or if they were invisible
to them. Then they asked the kids whether the researchers
would be able to see adults if those adults were
wearing eyemask like their's, and unsurprisingly, nearly all the kids
said they were hidden from view while their eyes were covered,
(37:33):
and most of them actually thought the imask would make
the adults invisible too, which is super cute. But did
the researchers have any ideas for why almost every child
subscribes to that weird logic. Well, actually, here's where things
get really interesting. And because when kids had their eyes covered,
they felt invisible, which fair enough, I mean, I think
we've all heard that before. But the researchers started to
(37:53):
press them on what invisibility meant, and surprisingly, the kids
conceded that their bodies weren't actually hidden it all. In
the sixth so they admitted their bodies could still be
seen even when their eyes were covered. So what do
they mean by invisible? Well, that's the weirdest part and
where this gets a little deep here. So the implication
was that the kids felt it was their true self
that was being hidden from view. So basically, they were saying,
(38:16):
I know, you can still see my arms and my
legs and all that when my eyes are closed, but
you can't see me, which is which is pretty existential,
you know, I know. It's it's like the children share
some natural distinction between, you know, the physical body and
the metaphysical self. And I just find this stuff fascinating.
And you know, because most adults tend to think of
(38:36):
their consciousness and their body being joined together in some way,
and studies like this suggests that perception might be something
we only adopt or maybe decide on later in life. Yeah,
that's especially interesting when you think about how people always
say the eyes of the window to the soul, or
that eye contact Foster's understanding. I mean, in some ways,
covering your eyes really is like withdrawing yourself from the
(38:58):
world and making yourself from visible. Alright, well, Mango, you
need to keep those eyes open, because there's only one
thing you can't hide from, the PGG fact off exactly.
All right, here's something I hadn't thought about. Any lightbeam
(39:20):
weapon you see in the movies, from photon torpedoes to
invisible rays, they're all things you won't see coming. So
anytime a sci fi hero is in a jet dodging
those rays, none of that's possible. You know that some
of the things you see in movies you just ruined
all movies did so I want to know a figure
who's basically become invisible. Jeremiah Dummer. Most people know Yale
(39:41):
University is named for Elihu Yale, but Dumber probably did
more for the early university in terms of securing funds
and building its reputation. The problem is, Dumber College isn't
a great name. While reindeer are good at spotting polar bears.
Cameras aren't, so when scientists decided to use infrared cameras
to locate the bears, they were stunned. But polar bears
are basically invisible to infrared cameras too. While cameras can
(40:04):
pick up the heat off their nose and their breath,
their blubber basically does such a good job of trapping
the heat within that their fur is essentially the same
temperature as all the snow around it. So despite all
the safety features and cars with backup cameras and beeping sensors,
people still back up into lampos. So researchers at Kyo
University in Japan have come up with back seats that
(40:25):
actually turned transparent when you back up. Basically, it's a
backup camera that projects on the seats, but it does
the trick of seeming transparent and of course making the
children sitting in those seats disappear as another matter, definitely,
all right, here's a fun one about not being seen.
A building supervisor in Spain skipped work for six years
and kept collecting his salary. You know the only reason
(40:46):
he got caught. People got suspicious when he won an
award for twenty years of loyal service. In two thousand
and six, magician David Copperfield and his two assistants were
walking down the street when Mugger's approached and demanded all
their money and wild assistants forked over plane tickets, cell phones,
and over five in cash. Copperfield used sleight of hand
to show the gun wielding robbers that his pockets were empty.
(41:09):
He reperformed the trick at the police station and wow
the officers, showing them he actually had a passport and
lots of cash on him the whole time. I know
he's such a performer, but he did help catch the
bad guys and I kind of love it all right. Well,
in that case, I'm gonna have to give you today's
championship belt. So that's it for today's episode. Thanks so
much for listening, Thanks again for listening. Part Time Genius
(41:44):
is a production of how stuff works and wouldn't be
possible without several brilliant people who do the important things
we couldn't even begin to understand. Chris and McNeil does
the editing thing. Noel Brown made the theme song and
does the MIXI mixy sound thing. Jerry Rowland does the
exact producer thing. Gay Bluesier, our lead researcher, with support
from the Research Army, including Austin Thompson, Nolan Brown and
Lucas Adams and Eve Jeff Cook gets the show to
(42:06):
your ears. Good job, Eves. 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 a good review
for us. Do we do? We forget Jason? Jason who
Guess what, mango, what's that? Will? I was reading this
whole story about a bank robbery that happened in 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
(00:21):
thing is when the cops come fromm he was totally baffled. Well,
he kept saying, I was wearing the juice. The juice, Well,
apparently he poured lemon juice all over his face because
he knew it could be used as this invisible ink
for writing. And the poor guy, he was really bewildered
because he said he tested it out, and the cops
pressed him for details, and he said the lemon juice
(00:42):
had gotten in his eyes the first time when he
poured it all over his face, and then he took
a selfie to see if it had worked. And the
combination of squinting and not being accustomed to taking his
own photo, I mean, this this was well, it made
him take a photograph that he wasn't in and he
just believed that he was invisible. I know you almost
feel bad for the guy, but you know, reading up
(01:04):
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,
(01:36):
welcome to Part Time Genius. I'm Will Pearson and as
always I'm joined by my good friend Man Guesh, I'll
Ticketer and over there on the other side of the
glass with the biggest smile that you can't see is
Tristan McNeil, our producer, And on today's show, we're taking
a WorldWind tour of our invisible world and trying to
get a better grasp of all things unseen. You know,
the idea of invisibility is fascinated mankind for thousands of years.
(01:57):
It's parts of our myths and our folklore and pop
culture and even our psychology. Of course, there are lots
of different kinds of invisibility, so this will be a
super fun Hodgepodge episode where we cover as much as possible.
We'll talk to a couple of insightful authors who have
devoted years of study to stuff we can't see. So
who do we have on the line today, Mango, Today
(02:17):
we're talking to Bob Berman, one of America's top astronomy
writers and author of a brand new book about the
curious history of invisible light. It's called Zapped, and it's
incredible and we'll have some wonderful quizzes along the way
as usual. All right, So, in honor of Bob's new book,
I want to dive straight into the science and talk
about light, and more specifically invisible light. You know, obviously
there are large portions of the electromagnetic spectrum that we
(02:39):
have no trouble observing, but there's also a huge part
that's totally invisible to us. That's the part that includes
things like ultra violet light and for red light, radio waves, microwaves,
X rays, gamma raves, you know, all that good stuff. Yeah.
I mean, I always knew there were parts of the
spectrum beyond our range of vision, just like you know
there's sounds outside the limits of human hearing. But reading
(03:00):
Bob's book put the vastness of light in a completely
new perspective for me, and it really blew me away.
So Burman rights, there's more light in the universe than
anything else. So if you were to add up every
individual light photon in the cosmos, they would account for
nine point of everything there is. And those forms of
invisible light you listed off, that actually makes up the
(03:22):
vast majority of the light. I actually can't wrap my
head around that fact that it seems unbelievable, but you know,
our eyes are designed to recognize only the Sun's most
abundant energy, so we really can only see the colors
that the Sun emits most strongly. And even though the
whole universe is light, the bulk of it, it's completely
invisible to us. We've actually figured out all kinds of
(03:43):
ingenious ways to measure and observe forms of invisible light.
And one of the most interesting things I came across
while prepping for this episode was the way human observation
actually affects the behavior of light. All right, well, I
think this is pretty complicated, so why don't you break
it down a little. Well. When quantum theory became all
the rage in the twentieth century, scientists started noticing something
super weird. They found that when they use special equipment
(04:05):
to pinpoint the location of photons, these tiny bits of
matter always behaved as particles. For example, they could pass
through one tiny hole or another in a barrier, but
not through both holes at once. All right, so far,
so good, and particles do what particles do that. I
don't think there's anything weird about that, right, But the
scientists also discovered that when they didn't try to determine
the exact location of each photon, the photons behaved as
(04:28):
waves instead of particles. So the photons were then able
to pass through both tiny holes in a barrier at
the same time. And that's something that only waves can do,
not particles. Okay, alright, I spoke through soon. That's really weird.
And so you're saying that light, photons and other sub
atomic matter act like particles, you know, when they know
we're watching, and then like waves when they know we
aren't looking. Yeah, it's something like that. So obviously the
(04:51):
photons themselves aren't aware of us watching them, but they
definitely seem to act differently based on how closely we
observe them. And the best explanation, at least according to
most physicists, is that when we look closely, our brains
halt the wave pattern so that we can see the
photon in a certain place as a particle. It just
makes us feel better that way. That's really insane, all right,
So where does that leave us? Does light exists as
(05:13):
a wave or as tiny bits of almost invisible matter? Yeah,
it's both. So Bob Berman sums up the paradox this way,
and I'm going to quote him here. He says, just
a century ago, the local realism mindset of science and
even common sense held that all objects, including atoms and photons,
have an existence independent of our observation of them. But
(05:33):
that's been replaced by a more modern view that our
observation itself is necessary for the very existence of a
photon or an electron. A spooky prospect, no kidding. Yeah,
So he continues, it possessed no real existence as an
actual photon or electron or whatever it was. Rather, it's
observed existence is it's only existence. The observation establishes reality,
(05:54):
nothing else is certain. That's pretty trippy. Yeah, the stuff
feels so philosophical, and especially when you go from a
micro perspective to a macro one, because just like with photons,
the color and brightness of light doesn't exist outside the
experience of the observer. We only see light as a
certain color because of how it stimulates the cones in
our eyes and how our brain interprets those signals. Well,
(06:16):
that's a good point, but it's also kind of a
terrifying mean. It means the external world is really just
as invisible as a UV ray, because outside of human observation,
there is no color or brightness. It's just this mix
of different invisible energy pulses. Actually, by the way, that
this is off topic, but did you read about the
women that supposedly have four cones in their eyes instead
(06:36):
of three, and as a result, they can see hundreds
of millions of color. That's a wild Yeah, they're called tetrachromats.
But baby, we're clinging too tightly to the human experience.
And you know, I actually did some digging to see
if there were any animals whose vision best ours in
terms of light perception, and it turns out there quite
a few that put the invisible spectrum to pretty good use. Awesome,
(06:57):
So give me the load down. Well, one case where
plenty of animals have a speed is the ability to
perceive ultra violet light. Invisible UV radiation is all around us.
And while it's useful for getting a golden tan, it's
also a menace because exposure to it can lead to
melanoma and other illnesses. But that hasn't stopped some animals
from making the most of UV light. There's some species
(07:18):
of birds that have plumage that you know, to our
eyes look the same between males and females. But if
your vision allows you to see the UV range like
those birds are able to see it, you know you'd
be able to make out the uvy markings that distinguish them.
So those markings make it easier for the birds to
find a meh definitely, but that's actually only part of it.
Some other birds determine which chicks to feed based on
(07:39):
how much UV light you know their heads reflect. For
whatever reason, the heartier birds tend to have a shinier
crest than their weaker siblings, so when the mama bird
has limited food to share, she'll go with whomever has
the most shine. There's also the fact that urine and
feces of mice and other small prey are visible in
the ultraviolet range, so birds that are sensitive to UV
light can use these traces to track their prey even
(08:02):
in a place where everything is uniform in color, you know,
like a green field or something like that. But you know,
birds aren't the only ones that can do this. You
have rodents and bats and even some marsupials that can
see UV light for similar reasons. So I actually think
I read something about butterflies also having great ev perception,
and I think they use it to identify which flowers
are currently producing nectar based on the color of the
(08:25):
petals or something. Well, yeah, I'm glad you mentioned that,
because butterflies with a high sensitivity light are often considered
to have the widest visual range of any form of wildlife.
It's crazy the invisible world might be the most visible
to butterflies of all things. But before we move on,
there's one last animal I want to talk about, and
that's the reindeer. So I'm sure there's a Rudolph joke
(08:47):
in here somewhere, but not telling reindeer can see ev risk. Well,
it sounds strange at first, but reindeer of evolved to
take full advantage of the ultraviolet range. And they're not
the only ones. There are other Arctic mammals who make
their home at the Earth's polls, and they have to
deal with much higher levels of UV light. Yeah, the
thinning ozone layer doesn't block as many rays as it
used to, especially in those upper latitudes. Yeah, exactly. So
(09:10):
there was this study of the University College of London
and the University of Tromso in Norway, and they found
evidence that not only a reindeer resistant eye damage from
intense UV rays, they're also able to see UV light
and this helps them find food and avoid predators. And
in the winter, reindeer primarily do two things. They eat
lichen and they try to avoid being eaten by wolves.
(09:31):
And wouldn't you know it, lichen and the fur of
wolves both absorb UV light. So because snowy landscape strongly
have reflect UV rays, you got reindeer that can spot
lichen and wolves with ease. Yeah. That's really cool, And well,
I think you and I could nerd out on reindeer
facts for a while, Like how Norwegian scientists wanted to
get closer to reindeers so they could study them better,
(09:52):
So they wore polar bear costumes and did that work. No,
not at all, like it's scared off the reindeer. But
they also wrote a scientific paper on reindeers reactions to costumes,
and we're hoping to redo the study with better costumes,
like like a clown costume. I like how they just
went off track there, Like that didn't work, So let's
just do costumes. How about clowns? How about police officers?
(10:12):
Science is great, but what I was saying was I
think we should shift the topic a little. All right, well,
what do you what do you want to talk about?
Secret messages? So last year a group of scientists and
friends developed a special kind of paper that can carry
secret messages. It looks just like plain old paper, but
you can use different wavelengths of UV light to read, write,
or even erase the messages that can't be seen invisible light.
(10:33):
So how does that work? So apparently the paper has
this special kind of molecule bonded to its cellulose fibers
that reacts and turns fluorescent when exposed to UV light.
The idea is you can write messages on the paper
using a stencil to produce dark and bright areas that
react differently under the UV lamp. But the really cool
thing is that the process is completely reversible. You can
(10:54):
expose the used paper to a shorter wavelength of UV
light that erases the message completely, and that way of
paper can be used over and over. I mean, it
is kind of cool, but what's the advantage over you know,
the disappearing reappearing and visible length that our kids play
with and stuff like that. So why is this better
than that? So not only are the messages on this
paper undetectable under visible light, they also can't be dissolved
(11:16):
with other chemicals. So it's the super useful tool in
anti counterfeiting and tracking operations. A good job, France, you know.
I actually want to dive into some of the historical
obsession with invisibility and the ridiculous potions humans used to make.
But before we do that, how about we check in
with Bob Burman and see if he can tell us
a little about the cool properties of light and how
humans have managed to turn something invisible to our advantage.
(11:42):
So in this episode on All Things Invisible, we've been
talking a little bit about this great book, Zapped, and
we're really lucky to have one America's top astronomy writers
on with us and the author of this book. It's
Zapped From infrared to X rays, The Curious History of
invisible Light. Bob Berman, Welcome to part time genius. Thank
you great to be here. All right, well let's just
start with the basics. So can you explain to us
(12:04):
where light comes from. Well, all lights, except for gamma rays,
comes from one source only, and that is atoms. If
the atomy gets excited in any way, electricity, collisions, anything
can may be excited, madam, so that the electrons are
In the case of hydraten, it's only got one electron
jumps to a higher orbit because it's excited. It really
(12:28):
doesn't like to be there. So in a fraction of
the second, it'll tumble down closer to its nucleus, and
that is what causes any kind of light. And the
distance that it tumbles down determines the color of the
light and therefore whether it's visible or invisible. So I
know you talk about this in your book, but what
(12:49):
did ancient people think about light? And were they aware
of invisible light? They felt about light as at first
something that comes from the eye, and then later on
as an interaction between a beam from the eye and
external objects. So they got it wrong for a long time.
They realized that it involves something very fast speed, but
(13:13):
nothing more than that, and nobody foresaw invisible light until
the time of the Renaissance of the Middle Ages. It
was one of those things that no wise person or
Greek philosopher, or scientists or religious order, nobody came up
with the idea that there might be kinds of light
(13:34):
out there that our eyes can't see well. In the Renaissance,
as you mentioned, you know, with this idea of invisible
light being a possibility, how did this start to be discovered? Well,
it's really William Herschel who found the first kind. He
projected sunlight through a prism piece of cut glass onto
a tabletop, so you had the whole rainbow of colors.
(13:56):
And then he put a thermometer in each color, and
he had other themometers on the side in the darkness
to act as controls. And so he noticed that when
the thermometer was in the blue or the green part
of the spectrum, the temperature went up very little. In
the yellow and went up more, and the red they
went up still more. But then he took a break,
(14:17):
and when he came back some minutes later, the sun
had moved across the sky, so the spectrum on the
table had shifted, and now his thermometer on the table
was no longer in the visible light instead of was
sitting in a spot of darkness outside of the spectrum,
just beyond the red end of the spectrum. And he
(14:37):
looked down on it, and now the thermometer was crazy.
Who had it was registering much more heat than any
color did. And so he repeated this and he realized
that the blank spot beyond the red part of the
spectrum was heat, was producing more heat. Well, he realized
(14:58):
it had to be an invisible kind of light that
was creating the heat. And he called these calorific rays.
Later on we came to call it infrared. So that
was the first kind of invisible light ever discovered. Wow. Wow.
And you also talked in the book about the discovery
of of X rays and I'm curious what the you know,
(15:18):
the public response was to this discovery. Well, X rays, Yeah,
that changed the world too. That was Renkin, and he
was boy. He had fame, and he would have had
fortune too if he had patented it, but he didn't.
Generously just allowed the world to use it, and almost
right away people realized the value in medicine that you
(15:41):
could use X rays and find a bullet wear a
bullet was my body for someone who had been shot
or were broken, bones were broken, And but nobody knew
at the time that X rays also had a dark side,
that it could produce harm as well as benefits. What
new opportunities for the use of invisible light are the
horizon and things like medicine or technology or culture, well
(16:04):
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 when we're on a camping trip, or use our
cell phones, those are all parts of the radio spectrum.
And then we know about the infrared. We use heat labs,
we use garage door openers, that are they're using infrared
and ultra violet. That's boy, that's the one with the
two edged sword. Ultra violet is both the most dangerous
(16:49):
form and the most valuable for our health. And what
makes UV rays so harmful to us, Well, they're the
beginning of the part of the spectrum that has the
power to ionize and others to strip electrons from adams
and therefore to change genes, to change chromosomes, to alter DNA,
(17:10):
and that could give rise to cancer, and it does
the eight thousand or so melanoma deaths per year. Skin
cancer are caused by generally too much UV, usually from
from from a bad sudden burn in our youth. And uh,
and that's why people nowadays know that they should be
(17:33):
putting on sunscreen and wearing hats and stuff like that.
But bad thing has happened from that too, in that
we've now blocked so much of the UV. That's strange
things are happening to our bodies that that most even
doctors are not aware of, although many are like like,
(17:53):
like what you do have some examples of this? Yeah, yeah,
and this has started. If I could give just a
bit of background, There was a time, of course, when
we were an agricultural society and we were out of
doors a lot, and we got plenty of sunlight and
therefore plenty of ultravolet, which is a few percent of
the sunlight and stimulates our bodies to produce U V
(18:17):
a vitamin D very quickly. That UV induced vitamin D
is such a avalanchingly fast process that we get more
U V from twenty minutes in the strong sunlight then
you would from drinking two hundred glasses of milk. So
somehow our bodies want lots of vitamin D production from UV.
(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
worst of all, this is something that they 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 of
of mold people where we're blocking the sun entirely and
not getting enough sunlight. They see it that it wasn't
that many decades ago. The kids after school. Of course,
(19:24):
during school they're not getting any UV and therefore not
producing any vitamin D. But after school kids used to
play outdoors and parents used to say, yeah, come back
at dinner time, and between they'd be out doing whatever
in the playground or climbing trees, and then that changed,
so their UV levels in their and their blood has
(19:44):
dropped to really, really low levels. So what does this
do is turns out that u V is one of
the strongest prevent ers of cancer. It stops cancers from growing,
so when they're tiny, pre detectable tumors, they don't get
any bigger. This year, for example, it was found that
(20:05):
pancreatic cancer is prevented by by adequate vitamin D triggered
by ultra violet light. So there are a lot of
health benefits also psychological benefits in terms of treatment for
depression and and things like that. If you get enough
(20:27):
sunlight induced h vitamin D, it's hard to strike that
strike that perfect balance. Now you're so right. At the
same time, you don't want to burn. So the people
like Dr Canell in the Vitamin D Council, they say
that we should get as much sun as we can
without burning, because everybody is so different and how much
(20:53):
sun they can handle before they start to burn. You know,
blue eyed, blonde people tend to burn fast, and camp
shouldn't get as much. Well, there are a thousand other
questions we could ask. This such a fascinating book. I
hope all of our listeners will check out zapp. But Bob,
thanks so much for joining us on Part Time Genius.
It's been a pleasure. Thanks so much. You're listening to
(21:27):
Part Time Genius and we're talking about the peculiar allure
of turning invisible, So mego. We mentioned at the top
of the show that humans have been obsessed with the
idea of invisibility from millennia, so I thought it might
be fun to take a look at some of the
weirdest attempts to go invisible that people have tried all
over the years. Yeah, so I'm definitely game. I spent
some time looking up medieval recipes and spells to turn
(21:47):
yourself invisible, and as you might guess, they're insane. So
one of my favorites is from the Ashmole, which is
this anonymous fifteenth century manuscript that collected over a hundred
eighty magical and magical recipes in English and Latin. So
this is the invisibility spell. It goes, if you wish
to be invisible, take a dead dog and bury it,
(22:08):
and plant a bean plant over it, and place one
in your mouth, and without a doubt you'll be invisible.
That that's it. It's simple. It's like one of these
great invisibility life hacks. But but don't worry. If you're
fresh out of dead dogs or beans, there's another suggestion
for you. Um this is also from the Middle Ages.
Grind up an owl's eye with the ball of beetle
(22:29):
dung and some olive oil and rub it all over
your body. I like the addition of the olive oil,
like weird stuff, and you just put some olive oil
in there that I think I'd rather eat the dead
dog being So why do they all have to be
so gross? So most invisibility charms that ties to a
cult practices so they tend to feature nasty ingredients like
the ivan a for a heart of a bat or whatever.
And one of them actually calls for the head of
(22:50):
someone who committed suicide, but stuffed with fava beans. God,
it's hard to imagine why any of these ingredients were
picked to be the ones that would turn you invisible,
But I don't know, and think about it. Might have
something to do with our desire for power, which seems
to be at the root of man's continuing quest for invisibility.
I mean, we have stories going all the way back
to antiquity that point to the dark side of going invisible. Yeah,
(23:12):
so there are all kinds of myths and folk legends
that warn about the corrupting power invisibility and how it
can lead even the most pure of heart heroes into
recklessness or voyeurism. And well, you know, these commonalities between
fables from different cultures. I find these fascinating. In this case.
They seem to suggest that we all know invisibility as
a power that we probably shouldn't have, and you know,
(23:34):
it doesn't stop us from wanting it though. And in fact,
the top two superpowers that people always cite is the
ones they'd most like to have, are the ability to
fly and the power to turn invisible. Yeah. So both
of those provide the user a crazy amount of freedom,
and maybe that's why we find them appealing. You know,
that could definitely be the case. But in keeping with
the shady side of invisibility we've been talking about that
(23:55):
there might be another explanation. And I couldn't find an
actual psychological study of this, but there is some speculation
about what the choice between flight and invisibility says about
a person. William Barry was this psychotherapist and professor at
Florida International University. He suggests that people who opt to
go invisible are embracing their dark side, you know, the
(24:15):
side of themselves that they typically don't like to acknowledge
as being part of them. So this is the side
of your psyche where all your most shameful thoughts and
desires dwell. According to Barry, quote many of those who
choose invisibility do so to hear what others say about
them when they aren't around, or to spy on others,
or to procure things that they don't have the money
to pay for. It's easy to see how this relates
(24:37):
to the dark side. Yeah, it really is, especially when
you compare it to choosing flight, which is mostly appealing
as this form of fast travel or experiencing this different sensation,
but it doesn't seem to have any of the darker edge,
right And you know, Barry found that people who choose
power of flight generally see it as a way to
add excitement or fulfillment to their lives, whether that's from
you know, maybe rescuing people from burning buildings or just
(24:59):
zipping across the world to have dinner in Italy or
you know, something like that, which is interesting. You know,
there's another commonality between invisibility fables that we should probably
talk about, all right, and what's that invisibility cloaks. So
ancient Greek myths described caps and cloaks with magical properties
that made the were invisible to other mortal men, and
from their invisibility, cloaks have popped up in everything from
(25:21):
Welsh and Germanic folklore to modern day pop culture. Of course,
and I'm guessing being a big fan, you think of
Harry Potter definitely, so Harry Potter is never far from
my mind. But scientists have been hard at work on
cloaking devices for a while now, things that can mask
or completely hide an object or a person from sight.
And sometimes they're more successful than others, but all of
(25:42):
the most promising ones involved something called meta materials, and
it's just you know, some kind of super science cloth
or something more or less. So meta materials are basically
a kind of material that's engineered to have properties that
that don't occur in nature, and in this case, it's
a light bending property that manipulates the eye. So the
reason objects are visible to our eyes at all is
(26:03):
because objects distort light waves based on their shapes. But
when the light from an object reaches our eyes, we
see the object by recognizing those distortions. Alright, so meta
materials they somehow counteract this or so. The idea is
that the meta material forms a kind of shell around
the object, or a cloak, so the light rays bends
smoothly around the meta material and recombined on the other side.
(26:26):
And one helpful example I came across is that it's
kind of like water flowing around a rock and a stream.
I viewer on the far side wouldn't see anything unusual,
but both the meta materials shield and object in its
center would be completely invisible to him. It would look
like the lights bouncing off a smooth surface, which is
pretty cool. But I don't know. I have the say,
I've read so many headlines over the last few years
(26:48):
that claim we're this much closer to Harry Potter like
invisibility cloak. And you know, there are definitely some similarities
to what you're describing, but it's hardly a one to
one I mean, I mean, natural materials get their special
properties from the arrangement of atoms and there's no way
what's going on with these meta materials is the same thing. Yeah,
that's true, And these cloaking devices are more like chunky
(27:09):
rings and pyramids that fit over a stationary object right now,
rather than any sort of sleek piece of fabric. But
the technology is advancing pretty quickly. Well, I'm glad to
know that we're on our way towards that. But why
don't we break for a little quiz? Alright, So today's
show us about invisibility. We decided to bring on to
(27:31):
Seattle based artists who produced the delightful art series that
only shows up when it rains. Welcome to the show,
Peregon Church and Zach Fisher. Thank you great to be here.
I am so excited to have you on. And and
for you listeners who aren't familiar with rain Works, you
should definitely check out the photo gallery at www dot
rain dot works because it's fantastic. So can you tell
(27:53):
us a little bit about how you came up with
this idea of making invisible artwork that only shows up
in the rain. I love thinking of ways to use
materials that already exist in ways that they shouldn't be used.
And I came across this stuff called super hydrophobic coatings. Basically,
when you put it on the surface, he keeps it
from getting wet. And I thought, wow, that's super cool.
(28:16):
You're watching all this water roll off these clothes and
shoes and whatever. What if you put it on something
that changed color when it got wet, like concrete and
so you since it's a spray on the thing, you
could spray it through a stencil on the concrete and
as long as it was invisible and dry, you can
create art that was only visible when the surface is wet.
Would you tell our listeners a little bit about some
(28:36):
of the designs you do and how you make them interactive? Sure,
we like to do things that are positive, things that
don't make someone stay better. That's are really one of
the big motivations behind it. Because in Seattle and the
Pacific Northwestern general, people tend to suffer from sad seasonal
effect of disorder. The skies are gray and it's dreary
(28:56):
and wet all the time. So we figured we could
take that thing that causes the juriess the rain and
use it to make people smile. We did a lock
nest monster at a at a dock out in over
a lake here in Seattle Green Lake so that people
could stumble upon the monster while they were out on
rainy days. We do games. Sometimes you've done like it
(29:18):
Don't Touch the Lava game. Um, We've done like nostalgic
references to like characters that we love as like when
we were kids. So like we've done like a Peter
Pan rainwork, and like the Calvin and Hobbs rain work.
Basically just whatever we think would like cheer someone up
or make them smile or make them think when they
see it it's funny. I mean even hearing the examples
(29:40):
makes you smile. That's pretty great. And you've now turned
this into a business. So what are the best applications
of your rain works? And you know that you've seen
in the wild now, oh man, we've seen so many
from all over the world. Some people have done like
promposals or actual wedding proposals with them. We've seen people
use public sountains to make like dolphins that appear. Yeah,
(30:05):
there's one just like a day or two ago where
they coated a canvas with it and through water balloons
with like water based paint in them, through do a
gender reveal. Right back that was what that was. Yeah, Yeah,
that kind of works a little differently because our spray
doesn't repel paint, but it like reacted with it in
a certain way, so it does kind of make the
(30:25):
letters pop, but like not in the way you expect.
It's really interesting to see like a new application for it,
and that's really been the coolest thing is like just
since this started, it's really taken off just all around
the world, and we get like new one's popping up
in like Denmark and like Taiwan and like Armenia. Does
having worked on this project make you look forward to
(30:47):
rainy days? Like do you sit on benches waiting for
people to interact with the art? Oh? Absolutely. It has
completely changed our perspective on rainy days. And one of
our favorite things to hear when we tell people about
project is them the words coming out of their mouths,
oh my gosh, I can't wait till it rains now,
Like that means the world to us. We become so
(31:10):
hyper sensitive to it that every time it starts to
rain or like the forecast predicts range, like we're like
on the edge of our chieves, like we're preparing, we're
making work, our our whole work as well, depends on
the weather. For sure. We'll tell us a little bit
about your connection with the Awesome Foundation. Sure. When I
(31:30):
had this idea, it was just an idea, like on
a note in my phone for a long time, but
it was one of one of my favorites, and I
started mentioning it to people and eventually mentioned it to
a friend in Seattle who was part of the Seattle
chapter of the Awesome Foundation. For anyone doesn't know, the
Awesome Foundation is an organization that every month it's one
(31:54):
dollars the person with a cool idea or an awesome idea,
as they put it, No, it's things attached. So I
submitted this rain activated our idea, but we're not called
rain works do the Austin Foundation, And they accepted it,
and that was what really gave it the first push.
All right, well, I thought we should play a little
game with these guys, and Mango, you came up with
(32:16):
one that's appropriate from what what game are we playing
with a Peregrine and Zach, it's called I'm Only have
you in it rains? All right, we love your rainy
Day project, and we figured we'd give you a quiz
where all the answers involved rain and you can work
together on this. So you guys, ready, ready, alright? He
got five questions for you, all right. Number one, Gene
Kelly had a one hundred and three degree fever when
(32:38):
he danced the big number in this rainy movie. What
classic film are we talking about? For one? Number two,
Prince's manager questioned the decision to put When Doves Cry
and this movie slash album because the song didn't have
a baseline and he didn't think it would be a hit.
What Prince movie are we talking about? Purple? Yes? Alright?
(33:01):
Number three? All these culture references and depending on yours action,
he's really pulling through alright. Number three. During the filming
of this award winning movie, both Tom Cruise and Dustin
Hoffman thought the flick would be a clunker. The whole time.
They referred to it as two schmucks in a car.
What movie are we talking about? Wait? I got this one, Ramon,
(33:25):
alright with the big answer, here we go. Number four.
Before this actor won the role of Dwight Shrut on
the office seth Rogan had auditioned for the role. Who
are we talking about? Wilson? Yes, they both got that one,
all right. The last question see if you can get
the perfect score number five. This song, written by Paul
(33:46):
Shaffer and performed by the Weather Girls, was intended to
be a gay anthe much like Y M c A.
You know the name of the song, It's rain Man. Yes, alright.
How did they do a mango our ols when astounding
five for five, which means we'll be sending them our
top prize, a handwritten note to their mom or boss
singing their praises congratulations, m thanks so much. Yeah, that's awesome. Listeners,
(34:16):
please check out rain dot works when you get a second,
and thank you guys so much for all the work
you do and for putting smiles on so many faces
having us. Okay, well, so we talked about fictional invisibility
(34:39):
cloaks as well as the closest things we have two
real life ones. But there's one more thing I want
to talk about, and it's the psychological sort kind of
a psychological invisibility quote. I don't even know how that
would work. Is like a helmet that would block your
brain waves or something like that. Yeah that's a good guess,
but no, nothing like that. I'm actually talking about the
great study I came across about a nomena called it
(35:00):
invisibility cloak illusion, and that's the name researchers at Yale
University came up with for our mistaken belief that we
observe others way more than others observe us. All Right,
so this is kind of like us pretending that maybe
we're under invisibility cloaks when we're out in public, if
we're grocery shopping or walking our dogs or something like that,
exactly pretty much any time we're in public, really, So
(35:21):
the team describes it this way, and they're abstract. Quote,
whether at a coffee shop, in a waiting room, or
riding the bus, people frequently observe the other people around them,
Yet they failed to realize how much other people engage
in the same behavior, and that they therefore also are
being observed. Because it's logically impossible that people, on average
(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 that's pretty wild. I mean,
we feel like we're invisible when the fact that we
observe others should tell us just the opposite. Of this,
And I really can't understand why we make this silly mistake,
because it's just that we're egoman acts, and you know,
we think we're the observant person and the only observant
(36:03):
person in the room. Yeah, that's definitely part of it.
But at least there's a good reason why we think
that way. And why is that? Well, the researchers that
Yale concluded that social norms compel our neighbors to pretend
to be busy with something else if it looks like
we might catch them watching us. All right, so we've
secretly scoped out the competition at a job interview, or
a glance around the waiting room and a doctor's office,
(36:24):
and you know, just in case we need an alibi,
we have a magazine or something like that. It's funny
that we all assume we're the only ones who do this, though, Right,
so when it's actually so widespread and phenomena that it
even has its own name, researchers call it civil and attention.
I kind of like that. Yeah, But my favorite part
of the study is this line from the conclusion, however
irresistible the sensation of being invisible, maybe it is not
(36:47):
to be trusted. That sounds exactly right, and it actually
makes it me think of this this other study I
read on the logic of the game Peekaboo. Apparently it's
this great display of the kind of nonsensical logic that
most kids share, namely the idea that you can make
yourself invisible by just covering your own eyes. So the
study was what like scientists rounded up a bunch of
toddlers and had this epic peekaboo session, Not exactly, but
(37:10):
but kind of. So the researchers at the University of
Cambridge had a group of three and four year olds
where I'm asked, and then they asked them whether they
could be seen by researchers or if they were invisible
to them. Then they asked the kids whether the researchers
would be able to see adults if those adults were
wearing eyemask like their's, and unsurprisingly, nearly all the kids
said they were hidden from view while their eyes were covered,
(37:33):
and most of them actually thought the imask would make
the adults invisible too, which is super cute. But did
the researchers have any ideas for why almost every child
subscribes to that weird logic. Well, actually, here's where things
get really interesting. And because when kids had their eyes covered,
they felt invisible, which fair enough, I mean, I think
we've all heard that before. But the researchers started to
(37:53):
press them on what invisibility meant, and surprisingly, the kids
conceded that their bodies weren't actually hidden it all. In
the sixth so they admitted their bodies could still be
seen even when their eyes were covered. So what do
they mean by invisible? Well, that's the weirdest part and
where this gets a little deep here. So the implication
was that the kids felt it was their true self
that was being hidden from view. So basically, they were saying,
(38:16):
I know, you can still see my arms and my
legs and all that when my eyes are closed, but
you can't see me, which is which is pretty existential,
you know, I know. It's it's like the children share
some natural distinction between, you know, the physical body and
the metaphysical self. And I just find this stuff fascinating.
And you know, because most adults tend to think of
(38:36):
their consciousness and their body being joined together in some way,
and studies like this suggests that perception might be something
we only adopt or maybe decide on later in life. Yeah,
that's especially interesting when you think about how people always
say the eyes of the window to the soul, or
that eye contact Foster's understanding. I mean, in some ways,
covering your eyes really is like withdrawing yourself from the
(38:58):
world and making yourself from visible. Alright, well, Mango, you
need to keep those eyes open, because there's only one
thing you can't hide from, the PGG fact off exactly.
All right, here's something I hadn't thought about. Any lightbeam
(39:20):
weapon you see in the movies, from photon torpedoes to
invisible rays, they're all things you won't see coming. So
anytime a sci fi hero is in a jet dodging
those rays, none of that's possible. You know that some
of the things you see in movies you just ruined
all movies did so I want to know a figure
who's basically become invisible. Jeremiah Dummer. Most people know Yale
(39:41):
University is named for Elihu Yale, but Dumber probably did
more for the early university in terms of securing funds
and building its reputation. The problem is, Dumber College isn't
a great name. While reindeer are good at spotting polar bears.
Cameras aren't, so when scientists decided to use infrared cameras
to locate the bears, they were stunned. But polar bears
are basically invisible to infrared cameras too. While cameras can
(40:04):
pick up the heat off their nose and their breath,
their blubber basically does such a good job of trapping
the heat within that their fur is essentially the same
temperature as all the snow around it. So despite all
the safety features and cars with backup cameras and beeping sensors,
people still back up into lampos. So researchers at Kyo
University in Japan have come up with back seats that
(40:25):
actually turned transparent when you back up. Basically, it's a
backup camera that projects on the seats, but it does
the trick of seeming transparent and of course making the
children sitting in those seats disappear as another matter, definitely,
all right, here's a fun one about not being seen.
A building supervisor in Spain skipped work for six years
and kept collecting his salary. You know the only reason
(40:46):
he got caught. People got suspicious when he won an
award for twenty years of loyal service. In two thousand
and six, magician David Copperfield and his two assistants were
walking down the street when Mugger's approached and demanded all
their money and wild assistants forked over plane tickets, cell phones,
and over five in cash. Copperfield used sleight of hand
to show the gun wielding robbers that his pockets were empty.
(41:09):
He reperformed the trick at the police station and wow
the officers, showing them he actually had a passport and
lots of cash on him the whole time. I know
he's such a performer, but he did help catch the
bad guys and I kind of love it all right. Well,
in that case, I'm gonna have to give you today's
championship belt. So that's it for today's episode. Thanks so
much for listening, Thanks again for listening. Part Time Genius
(41:44):
is a production of how stuff works and wouldn't be
possible without several brilliant people who do the important things
we couldn't even begin to understand. Chris and McNeil does
the editing thing. Noel Brown made the theme song and
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(42:06):
your ears. Good job, Eves. If you like what you heard,
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