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What is an impossible color? · Daniel and Kelly’s Extraordinary Universe

• 0:07
  Speaker 1: Hey, Orgy. As an artist, do you have a favorite
• 0:10
  Speaker 1: color that you use for scientific cartoons or some colors
• 0:14
  Speaker 1: more sciency than others.
• 0:16
  Speaker 2: Well, it depends on the science. I mean some science
• 0:18
  Speaker 2: it's just more colorful than others.
• 0:20
  Speaker 1: So then what's the color of physics?
• 0:23
  Speaker 2: It kind of depends on the topic too. If it's
• 0:25
  Speaker 2: about lasers, I might use red, or if it's about
• 0:28
  Speaker 2: the sun, I might use a yellow. I've used cian
• 0:31
  Speaker 2: for particle physics.
• 0:34
  Speaker 1: What makes particle physics cian?
• 0:37
  Speaker 2: I don't know. That just kind of would seem like
• 0:40
  Speaker 2: fit to the topic at the time.
• 0:42
  Speaker 1: It just gives you the blues.
• 0:43
  Speaker 2: Yeah, Or if it's a red hot topic, I might
• 0:45
  Speaker 2: go for a nice intense red. But for our books
• 0:48
  Speaker 2: they usually go with purple.
• 0:49
  Speaker 1: Yeah, what's purple about our curiosity?
• 0:52
  Speaker 2: It's more about the process, you know. It's kind of
• 0:55
  Speaker 2: mentally bruising, I mean mentally enlightening.
• 0:59
  Speaker 1: I think it's position of both of those.
• 1:01
  Speaker 2: It's both blue and red, which makes purple. There you go. Hi,
• 1:20
  Speaker 2: I'm Hoorham Mack, cartoonas and the author of Oliver's Great
• 1:22
  Speaker 2: Big Universe.
• 1:23
  Speaker 1: Hi, I'm Daniel. I'm a particle physicist and a professor
• 1:26
  Speaker 1: at U see irvine, and my daughter tells me I
• 1:29
  Speaker 1: can't see mad.
• 1:30
  Speaker 2: WHOA, wait, does that mean that you can't get mad
• 1:34
  Speaker 2: or that you don't see the color red?
• 1:37
  Speaker 1: Yes, As a parent of a stubborn toddler, I never
• 1:40
  Speaker 1: once got mad. Absolutely kept my cool every single moment.
• 1:45
  Speaker 3: No.
• 1:45
  Speaker 1: She and I disagree a lot about what to call
• 1:47
  Speaker 1: various colors, and she's convinced I'm partially colorblind.
• 1:50
  Speaker 2: WHOA have you ever had it checked? Maybe it's true.
• 1:53
  Speaker 2: What does that mean? You can't tell colors apart? Or
• 1:55
  Speaker 2: you can't seek certain colors? But how do you know
• 1:57
  Speaker 2: you can't see them?
• 1:58
  Speaker 1: You can do these tests where you to see numbers
• 2:01
  Speaker 1: out of dots. But she just likes showing me lots
• 2:03
  Speaker 1: of different shades and asking me to come up with
• 2:06
  Speaker 1: names of them. And I'm always like, I don't know
• 2:07
  Speaker 1: wild Mountain raspberry, and she's like, that's not red, it's
• 2:10
  Speaker 1: purple or something.
• 2:13
  Speaker 2: Sounds like she just likes to disagree with you.
• 2:15
  Speaker 1: Yeah, I think I raised her right.
• 2:19
  Speaker 2: Yeah, you raised her to make you read all the time.
• 2:24
  Speaker 2: But anyways, welcome to our podcast. Daniel and Jorge Explain
• 2:26
  Speaker 2: the Universe, a production of iHeartRadio, in.
• 2:28
  Speaker 1: Which we try to pencil in an explanation for how
• 2:32
  Speaker 1: the universe works. We try to color inside the lines
• 2:35
  Speaker 1: and help you understand how this incredible, glittering, beautiful, bizarre
• 2:39
  Speaker 1: and crazy cosmos actually works, how all those quantum mechanical
• 2:43
  Speaker 1: little particles come together to emerge into this incredible experience
• 2:47
  Speaker 1: that we all enjoy.
• 2:49
  Speaker 2: That's right. We try to paint a picture for you
• 2:51
  Speaker 2: of our amazing and beautiful universe, using all of the
• 2:53
  Speaker 2: hues of the rainbow to try to communicate to you
• 2:56
  Speaker 2: all the feelings and impressions that the universe has in
• 3:00
  Speaker 2: us as a human race.
• 3:01
  Speaker 1: And in the end, science is trying to build a
• 3:03
  Speaker 1: bridge between our visceral experience what you actually feel is
• 3:07
  Speaker 1: a conscious entity, and our mental picture of what's out
• 3:10
  Speaker 1: there in the universe, the mental model we're all putting
• 3:13
  Speaker 1: together trying to explain how the universe itself, absent from
• 3:16
  Speaker 1: our humanity, actually works. But in the end, we never
• 3:19
  Speaker 1: probe that deep reality independent of our senses. We're only
• 3:23
  Speaker 1: limited to understanding how it works as filtered by our
• 3:26
  Speaker 1: eyes and ears and fingertips and everything else.
• 3:29
  Speaker 2: Yeah, and as we look at the universe and filter
• 3:31
  Speaker 2: it through our eye. Sometimes it makes us red with
• 3:34
  Speaker 2: anger about the things we don't understand, or blue about
• 3:37
  Speaker 2: the things we may never understand, and sometimes maybe even
• 3:40
  Speaker 2: green and envy of maybe possible aliens out there that
• 3:42
  Speaker 2: have figured it out. Did it miss a color? Orange?
• 3:48
  Speaker 2: Mass orange? For a nice glass of orange?
• 3:51
  Speaker 1: Aren't you glad you made that pun?
• 3:53
  Speaker 2: Nice?
• 3:54
  Speaker 1: All these things are part of our experience. The color
• 3:57
  Speaker 1: purple in your mind is not actually part of the universe,
• 3:59
  Speaker 1: is just part of your experience of the universe. Somehow,
• 4:03
  Speaker 1: over the centuries and millennia, we have been able to
• 4:06
  Speaker 1: piece together a picture of how the universe out there
• 4:08
  Speaker 1: might actually work, perhaps independent of our senses, though of
• 4:12
  Speaker 1: course we won't know until those aliens come and talk
• 4:15
  Speaker 1: to us about the colors they see in the universe.
• 4:18
  Speaker 2: Do you think they're a colored line too? Like Daniel,
• 4:21
  Speaker 2: we think the answer to the universe is a light
• 4:25
  Speaker 2: shade of lavender summer breeze. And then we would end
• 4:29
  Speaker 2: up disagreeing about what that means.
• 4:30
  Speaker 1: Yeah, I think whatever answer they have, my daughter will
• 4:32
  Speaker 1: disagree with him. That's how I raised her.
• 4:36
  Speaker 2: Let's not put her in the greeting committee.
• 4:38
  Speaker 1: I think we agree on that Oh my gosh. Yes,
• 4:40
  Speaker 1: let's not send Daniel's children to meet the aliens.
• 4:43
  Speaker 2: Yeah, unless they start an intergalactic war.
• 4:49
  Speaker 1: Maybe the colors are sacred to them, and if Hazel
• 4:51
  Speaker 1: disagrees about what's purple and what's red, she's going to
• 4:54
  Speaker 1: really piss them off.
• 4:55
  Speaker 2: Yeah, or they might disagree about the color hazel itself.
• 4:59
  Speaker 1: That's right. Yeah, exactly why are.
• 5:02
  Speaker 2: You called hazel if you're not the color of a
• 5:04
  Speaker 2: hazel nut. That's it. Forget this human race. It doesn't
• 5:07
  Speaker 2: make any sense.
• 5:08
  Speaker 1: It doesn't make any sense. You know, we named it
• 5:09
  Speaker 1: her hazel before we knew her. But she does turn
• 5:11
  Speaker 1: out to light the color hazel and hazel nuts, so
• 5:15
  Speaker 1: there's a win.
• 5:15
  Speaker 2: Yeah, but how do you know she's actually seen the
• 5:17
  Speaker 2: color Hazel's hazel blind?
• 5:21
  Speaker 1: M hazel blind.
• 5:22
  Speaker 2: Wow, it's all hazey to her, it is.
• 5:27
  Speaker 1: But we are fascinated by this concept of color, not
• 5:30
  Speaker 1: just because it's such a visceral part of our experience,
• 5:33
  Speaker 1: but because it's deeply connected to the physics of what's
• 5:35
  Speaker 1: happening out there in the universe. It tells us something
• 5:38
  Speaker 1: about how photons are wiggling, or how neutrinos are flying
• 5:41
  Speaker 1: through the universe if you're willing to apply red and
• 5:44
  Speaker 1: blue shifts to them as well. So this concept of color,
• 5:47
  Speaker 1: what we see, what's out there in the universe, it's
• 5:49
  Speaker 1: very confusing but also very illuminating about how the universe
• 5:52
  Speaker 1: actually works.
• 5:54
  Speaker 2: Yeah, there's a lot of physics in light and in
• 5:56
  Speaker 2: all the colors. But then, as you said, it gets
• 5:58
  Speaker 2: filtered through our eyes and our brains, and sometimes what
• 6:01
  Speaker 2: we see is not quite what's out there, and maybe
• 6:05
  Speaker 2: there might be things out there that are maybe impossible
• 6:08
  Speaker 2: for us to experience.
• 6:09
  Speaker 1: Well, that's right. We know that there are frequencies of
• 6:12
  Speaker 1: light the humans can never experience, but are there also
• 6:15
  Speaker 1: colors that are impossible to see?
• 6:17
  Speaker 2: So to the end podcast, we'll be tackling the question
• 6:25
  Speaker 2: what is an impossible color?
• 6:28
  Speaker 1: It sounds like a job for Tom Cruise.
• 6:30
  Speaker 2: Dunt dunt dan da dunt dun.
• 6:34
  Speaker 1: This color will self destruct after you view it.
• 6:36
  Speaker 2: We need a movie in which Tom Cruise is a physicist. Yeah,
• 6:42
  Speaker 2: I mean he'd have to wear a lot of like
• 6:43
  Speaker 2: wigs and prosthetics. Of course, he can't look like Tom Cruise.
• 6:47
  Speaker 1: Yeah, he's too sexy to be a physicist. Is that
• 6:49
  Speaker 1: what you're saying? I didn't say that he violates some
• 6:53
  Speaker 1: physical law.
• 6:55
  Speaker 2: He's too orange.
• 6:56
  Speaker 1: He's definitely very physical, even if he's not a physicist,
• 6:59
  Speaker 1: Right he doesn't.
• 7:00
  Speaker 2: Yeah, that's right. Yeah. I wonder if he would do
• 7:02
  Speaker 2: his own stunts in a physics movie, Like would you
• 7:05
  Speaker 2: actually sit on the couch all day? I mean, that's
• 7:08
  Speaker 2: it's probably more dangerous and jumping off a cliff.
• 7:10
  Speaker 1: Then you put all those professional nap stunters out of work.
• 7:13
  Speaker 1: You can just take naps on film as a wait.
• 7:16
  Speaker 2: Wait, wait, that's a career. I can be a stunt
• 7:18
  Speaker 2: napper exactly.
• 7:20
  Speaker 1: Oh man, there's a career for everything.
• 7:21
  Speaker 2: They're doing it all this time for free. Daniel.
• 7:23
  Speaker 1: You know that the sign of an advanced civilization is specialization, right,
• 7:28
  Speaker 1: And I think once we've achieved stunt napping, we've reached
• 7:31
  Speaker 1: the pinnacle of civilizations. The aliens will be impressed.
• 7:35
  Speaker 2: Oh, they might even hire us to nap for them.
• 7:39
  Speaker 1: Well there's a.
• 7:40
  Speaker 2: Twist ending, but yeah, this is an interesting question, the
• 7:42
  Speaker 2: idea that there might be colors out there that are
• 7:44
  Speaker 2: impossible to create, to experience, to see, to generate what
• 7:49
  Speaker 2: side of the color spectrum.
• 7:50
  Speaker 1: Are we Yeah, it's a complicated question. Because color is
• 7:54
  Speaker 1: intimately connected with frequency, and we think about it as
• 7:57
  Speaker 1: controlled by light, but really it's something inside our minds,
• 8:01
  Speaker 1: it's something generated by our brain. It's an experience, and
• 8:05
  Speaker 1: the colors you experience in the end come from the
• 8:07
  Speaker 1: signals that travel up the optic nerve, which are not physical.
• 8:10
  Speaker 1: They're just interpreted by your brain. And so it's interesting
• 8:13
  Speaker 1: to think about whether there are colors that cannot be
• 8:16
  Speaker 1: described by those signals.
• 8:18
  Speaker 2: Oh boy, is this going to get into philosophy, Daniel, Like,
• 8:21
  Speaker 2: what colors can a bat see?
• 8:24
  Speaker 1: That's actually a great idea for paper. I'm gonna write
• 8:26
  Speaker 1: that when we're done with this episode.
• 8:28
  Speaker 2: Yeah, what color is your bad wing?
• 8:30
  Speaker 1: Everything in the end is philosophy if you care about
• 8:33
  Speaker 1: what it means. Right, So if you're going to answer
• 8:35
  Speaker 1: the question what does that mean anyway? Then yeah, you're
• 8:38
  Speaker 1: getting into philosophy.
• 8:40
  Speaker 2: That sounds like a philosophical statement in itself, Daniel.
• 8:43
  Speaker 1: The philosophy of philosophy.
• 8:45
  Speaker 2: Yeah, you can get a phphphd in recursive philosophy in
• 8:50
  Speaker 2: computer science philosophical puzzles well, as usually. We were wondering
• 8:53
  Speaker 2: how many people had thought about this question of what
• 8:56
  Speaker 2: is an impossible color, and so as usual, Daniel went
• 8:58
  Speaker 2: out there to the Internet to ask people this question.
• 9:02
  Speaker 1: Thanks very much to everybody who answers these questions for
• 9:04
  Speaker 1: the podcast. If you would like to hear your voice
• 9:06
  Speaker 1: on future episodes, please write to me two questions at
• 9:09
  Speaker 1: danielan Jorge dot com.
• 9:11
  Speaker 2: So think about it for a second. What do you
• 9:13
  Speaker 2: think is an impossible color? Here's what people had to say.
• 9:17
  Speaker 4: So, color is just a construct of our brain decoding
• 9:20
  Speaker 4: the frequency of electiation. If you think about it and
• 9:25
  Speaker 4: imagine our rods and cones were tuned a little wider
• 9:28
  Speaker 4: and we could actually see an infrared and ultraviolet, and
• 9:33
  Speaker 4: colors we can't see would be associated with those frequencies.
• 9:37
  Speaker 4: So I guess every color associated with low frequency radio
• 9:41
  Speaker 4: all the way to gamma rays would be impossible colors.
• 9:44
  Speaker 3: If color is just how we perceive different wavelengths of light,
• 9:48
  Speaker 3: and light can be in a huge range of wavelengths.
• 9:51
  Speaker 3: It has something to do with the limits of the
• 9:54
  Speaker 3: wavelength approaching either zero or infinity, where suddenly color doesn't
• 9:59
  Speaker 3: make any sense anymore.
• 10:02
  Speaker 5: An impossible color all very interesting. I'm going to say
• 10:08
  Speaker 5: some sort of combination of spectral outputs that are that
• 10:14
  Speaker 5: is a different spectral resolution than what our the receptors
• 10:19
  Speaker 5: of our eyes are able to something to do with
• 10:22
  Speaker 5: color metamerism.
• 10:25
  Speaker 2: The interesting answers. I feel like nobody pitched the idea
• 10:28
  Speaker 2: that maybe it's a color that's made out of plant based.
• 10:32
  Speaker 1: Proteins vegan colors.
• 10:34
  Speaker 2: Wow, yes, No, no animals or creatures were harmed in
• 10:41
  Speaker 2: the making of this color.
• 10:44
  Speaker 1: I can't even imagine a way you might harm an
• 10:46
  Speaker 1: animal to make a color you're talking about, like, oh,
• 10:49
  Speaker 1: let's see red, We're going to spill something's blood. Like
• 10:51
  Speaker 1: it seems pretty unnecessary.
• 10:53
  Speaker 2: I think, Daniel, you just don't have this strong enough imagination.
• 10:59
  Speaker 2: But there are colors that are based on or traditionally
• 11:02
  Speaker 2: there are dyes that are based on like insects, like
• 11:05
  Speaker 2: insect juice.
• 11:07
  Speaker 1: Oh yeah, okay, interesting, But.
• 11:09
  Speaker 2: I don't know how vegans draw that line.
• 11:11
  Speaker 1: You know, we're gonna have to have some of them
• 11:13
  Speaker 1: on the podcast to answer the question.
• 11:15
  Speaker 2: Yeah, sounds like good question for Katie. All right, well,
• 11:18
  Speaker 2: let's dig into this question of what an impossible color is.
• 11:21
  Speaker 2: Whether it means we can't see it, we can't make it,
• 11:24
  Speaker 2: it can't exist in the universe. Let's figure it out.
• 11:27
  Speaker 2: So you know, what are the basics of light and color?
• 11:30
  Speaker 1: Yeah, so let's start outside the human brain before we
• 11:33
  Speaker 1: get into like signal processing and all that stuff, and
• 11:36
  Speaker 1: just begin with light. Right, Light we know is made
• 11:39
  Speaker 1: of electromagnetic fields. There are ripples in electromagnetic fields, So
• 11:43
  Speaker 1: we have electrical fields that can be made by like
• 11:44
  Speaker 1: electrons and magnetic fields that have made my magnets. And
• 11:48
  Speaker 1: light is a coupling of the electric fields and the
• 11:50
  Speaker 1: magnetic fields together. Electric fields can induce magnetic fields, magnetic
• 11:55
  Speaker 1: fields can induce electric fields. Light is like this perfect
• 11:57
  Speaker 1: little packet where it's slashing back and forth between electric
• 12:00
  Speaker 1: fields and magnetic fields in amazing harmony, and they can
• 12:04
  Speaker 1: propagate through the universe, this little oscillation of the fields.
• 12:07
  Speaker 1: And these oscillations have frequencies that have a wavelength, they
• 12:10
  Speaker 1: have a frequency that relates to their energy. So if
• 12:14
  Speaker 1: you have a beam of light, for example, coming out
• 12:16
  Speaker 1: of a flashlight, it's actually made out of little photons,
• 12:18
  Speaker 1: and each photon has a specific energy which has a
• 12:21
  Speaker 1: specific wavelength and a specific frequency. So that's what light is, right,
• 12:26
  Speaker 1: these packets of photons.
• 12:27
  Speaker 2: So I have this laser and I'm shooting it, and
• 12:29
  Speaker 2: there are photons coming out of it, and each photon
• 12:32
  Speaker 2: is like a wiggle in the electromagnetic field. Is that
• 12:35
  Speaker 2: what it is?
• 12:36
  Speaker 1: Yeah, each photon is a wiggle in the electromagnetic field.
• 12:39
  Speaker 2: But it's not a wiggle that's like propagating, like if
• 12:41
  Speaker 2: I throw a pebble in a pond. It's not spreading
• 12:44
  Speaker 2: out there like that, right, Like in a laser. These
• 12:46
  Speaker 2: things are going in a straight line.
• 12:47
  Speaker 1: These things are going in a straight line. And we
• 12:49
  Speaker 1: just did a really fun but very confusing episode about
• 12:53
  Speaker 1: how long is the photon? And if you didn't listen
• 12:54
  Speaker 1: to that one, I.
• 12:55
  Speaker 2: Was going to listen to it, but it's a little long.
• 13:00
  Speaker 2: I'm not a light topic.
• 13:01
  Speaker 1: And that tells you that real photons out there in
• 13:04
  Speaker 1: the universe are a little packets. They have a length
• 13:07
  Speaker 1: that's determined by the spread of the frequency. So in
• 13:09
  Speaker 1: a sort of idealized sense, you can imagine every photon
• 13:12
  Speaker 1: has exactly one frequency. It's like a pure little packet
• 13:15
  Speaker 1: of one energy, one wavelength, one frequency. But that's actually
• 13:19
  Speaker 1: mathematically very confusing because if it was like that, it
• 13:21
  Speaker 1: would be everywhere in the universe. And so to build
• 13:24
  Speaker 1: up a little packet that actually moves through the universe
• 13:26
  Speaker 1: a little blob that stays together and flies through space.
• 13:30
  Speaker 1: You have to have a little bundle of frequencies, so
• 13:33
  Speaker 1: you know, blue photon is like a little spread of
• 13:35
  Speaker 1: various blue frequencies, and a red photon is a little
• 13:38
  Speaker 1: packet of a handful of differently red frequencies.
• 13:42
  Speaker 2: And they're all going at the same speed, which is
• 13:44
  Speaker 2: the speed of light.
• 13:45
  Speaker 1: Yes, exactly, they all got the same speed even though
• 13:47
  Speaker 1: they have a different wavelength and a different frequency, and
• 13:50
  Speaker 1: the speed of light is the same across the spectrum.
• 13:52
  Speaker 1: That's at least in our current theory. There are theories
• 13:54
  Speaker 1: of physics like rainbow gravity, where different frequencies travel at
• 13:58
  Speaker 1: different speeds and you get like effects around the edges
• 14:01
  Speaker 1: of black holes, but are in their current theory physics,
• 14:03
  Speaker 1: And according to all of our measurements, every photon travels
• 14:05
  Speaker 1: at the same.
• 14:06
  Speaker 2: Speed, and the spectrum of frequencies that light can have,
• 14:10
  Speaker 2: it's basically one dimensional, right, Like there's only one knob
• 14:15
  Speaker 2: for the frequency of light.
• 14:16
  Speaker 1: Yeah, if you're going to think about a photon.
• 14:18
  Speaker 2: From zero to infinity, hmm, But it's just a line,
• 14:21
  Speaker 2: and if you were to draw a plot of it.
• 14:23
  Speaker 1: Yes, exactly, it's one dimensional. It's a great way to
• 14:25
  Speaker 1: think about it. And it is infinitely dense, right, there's
• 14:28
  Speaker 1: an infinite number of frequencies there. We think of these
• 14:31
  Speaker 1: things as like, oh, they're quantum mechanical, so it must
• 14:34
  Speaker 1: be discrete, must be broken up into chunks, right, But
• 14:37
  Speaker 1: the reality is that free objects, even free electrons, are
• 14:40
  Speaker 1: not quantized in their energy levels. They're quantized in the
• 14:43
  Speaker 1: number of photons. Like you can't have one point seven
• 14:46
  Speaker 1: photons or two point two seven photons. You can have
• 14:49
  Speaker 1: one or two or nineteen. But each photon can have
• 14:53
  Speaker 1: any energy. There's no limitation, there's no quantitization, there's no
• 14:56
  Speaker 1: descritization of the energy spectrum. But yes, it is one
• 14:59
  Speaker 1: dimension all.
• 15:00
  Speaker 2: That you know of though, right, Like, is it possible
• 15:03
  Speaker 2: that maybe frequency is quantized as well.
• 15:05
  Speaker 1: Yeah, in our current theory that's the case. There are
• 15:08
  Speaker 1: theories of quantum gravity in which like space is pixelated,
• 15:11
  Speaker 1: which would make like a minimum wavelength, and in that
• 15:14
  Speaker 1: case every distance is quantized. In our current theories, there's
• 15:18
  Speaker 1: no minimum frequency, but that doesn't actually really make sense
• 15:21
  Speaker 1: below like the plank length, where every photon would like
• 15:24
  Speaker 1: collapse into a black hole anyway, So it only really
• 15:27
  Speaker 1: applies up to a very very high energy, but much
• 15:30
  Speaker 1: higher than we could probe today.
• 15:32
  Speaker 2: All right, So that's the physics of it. Now let's
• 15:33
  Speaker 2: get into the biology of it. So when these photons
• 15:37
  Speaker 2: hit our eyes, they create and experience in our brains.
• 15:41
  Speaker 1: Yeah, I think there's one step before that, which is reflection. Like,
• 15:45
  Speaker 1: let's imagine we're looking at a banana, right, why do
• 15:48
  Speaker 1: we see the banana as yellow? We see the banana
• 15:50
  Speaker 1: as yellow because white light hits the banana from the sun,
• 15:54
  Speaker 1: and then some of it is absorbed and some of
• 15:56
  Speaker 1: it is reflected. You start with almost every frequency of
• 15:59
  Speaker 1: light you can see the banana, But then the banana
• 16:01
  Speaker 1: has chemicals in it and atoms, and those atoms prefer
• 16:04
  Speaker 1: to absorb some colors and not absorb other colors. And
• 16:07
  Speaker 1: so when you see yellow as banana, that means that
• 16:11
  Speaker 1: the wavelength of light that is being reflected is a
• 16:14
  Speaker 1: specific band in this case, like between five hundred and
• 16:16
  Speaker 1: seventy and five hundred and eighty nanometers. So you see
• 16:20
  Speaker 1: something as red, it's not because it's like absorbing the
• 16:22
  Speaker 1: red light, right, It's because it's reflecting the red light
• 16:25
  Speaker 1: and absorbing everything else. But then yeah, it hits your eyeball,
• 16:29
  Speaker 1: and those photons with a certain frequency are now going
• 16:31
  Speaker 1: to be interacted with by your eye, which is like
• 16:33
  Speaker 1: basically little observational device.
• 16:36
  Speaker 2: But wait, the banana, So the banana absorbs all frequencies
• 16:39
  Speaker 2: except maybe the kinds that are my brain will interpret
• 16:42
  Speaker 2: as yellow.
• 16:44
  Speaker 1: Yeah, not all frequencies, but all visible ones. Right, banana
• 16:47
  Speaker 1: can't necessarily absorb all X rays and gamma rays or infrared,
• 16:51
  Speaker 1: but in the visible spectrum and again, and not even
• 16:54
  Speaker 1: all of that, right, Like you see it yellow because
• 16:56
  Speaker 1: it's dominant in the yellow. It's never like intense and
• 16:58
  Speaker 1: yellow and zero in every other frequency. You know, it just.
• 17:02
  Speaker 2: Peaks unless it's like a perfect banana. Like, is it
• 17:04
  Speaker 2: possible to create a perfect banana that only reflects like
• 17:07
  Speaker 2: one frequency of yellow.
• 17:09
  Speaker 1: If you make a shade which only reflects one frequency
• 17:12
  Speaker 1: of yellow, I think Hazel would call that perfect banana.
• 17:15
  Speaker 1: That is a nice name for a yellow.
• 17:18
  Speaker 2: Exact banana, yes.
• 17:20
  Speaker 1: Exact scientific banana.
• 17:22
  Speaker 2: Okay, So there's a reflection and also I mean there's
• 17:25
  Speaker 2: filtering too. But while we're talking about it, like it right,
• 17:29
  Speaker 2: like if I have rose colored glasses, the world looks
• 17:31
  Speaker 2: rose to me. Because it's filtering out all frequencies except
• 17:34
  Speaker 2: the ones that I see is rose.
• 17:36
  Speaker 1: Yeah, exactly, it's filtering. There's a reflection. All this affects
• 17:40
  Speaker 1: the frequencies that actually hit your eyeball. But I hear
• 17:43
  Speaker 1: a lot of confusion out there and the questions I
• 17:44
  Speaker 1: get from listeners about what makes something a color, whether
• 17:47
  Speaker 1: it's absorbing it or reflecting it, And so it's important
• 17:50
  Speaker 1: to remember that the color is something that's in your
• 17:52
  Speaker 1: eye depends on the light that hits your eyeball. You
• 17:55
  Speaker 1: can only see something if it hits your eyeball. For example,
• 17:58
  Speaker 1: if a photon was flying in front of you your face,
• 18:00
  Speaker 1: you couldn't see it right. If it just flies past you,
• 18:03
  Speaker 1: you don't see like a little glowing blob going through
• 18:06
  Speaker 1: the universe. You imagine your visual perception is giving you
• 18:09
  Speaker 1: an accurate description of everything that's out there in the universe,
• 18:12
  Speaker 1: but you only see things that hit your eyeball. Photon
• 18:14
  Speaker 1: that passes in front of you doesn't send any signals
• 18:17
  Speaker 1: to you, so you don't see it right.
• 18:19
  Speaker 2: Like if someone to my right shoots a laser to
• 18:21
  Speaker 2: my left, I won't see it. It has to be
• 18:22
  Speaker 2: they have to be shooting into my eye for me
• 18:24
  Speaker 2: to see the.
• 18:25
  Speaker 1: Laser, yeah, or it has to hit dust particles along
• 18:28
  Speaker 1: the way or air and ionize that and make a
• 18:31
  Speaker 1: glow or a reflection. Right, But a perfect laser in
• 18:34
  Speaker 1: a vacuum you will not see until it slices your
• 18:36
  Speaker 1: head open.
• 18:37
  Speaker 2: The photons, ever, split into other photons.
• 18:41
  Speaker 1: Photons can convert into electron positron pairs, which can then
• 18:45
  Speaker 1: interact with other stuff, like including other photons, and do
• 18:48
  Speaker 1: crazy stuff that differently could happen, and those could create
• 18:52
  Speaker 1: other photons, So that can happen, but it's quantum mechanically
• 18:54
  Speaker 1: pretty rare. If you pass a photon through a special
• 18:57
  Speaker 1: kind of non linear crystal, it can split into two
• 19:00
  Speaker 1: other photons. They use that for important experiments to like
• 19:03
  Speaker 1: detect single photons. But mostly photons just fly through the universe.
• 19:07
  Speaker 1: That's why we can see them after billions of years
• 19:10
  Speaker 1: and across billions of light years. They're pretty reliable indicators
• 19:14
  Speaker 1: of what emitted them.
• 19:16
  Speaker 2: All right, So photons can't have all these frequencies. Sometimes
• 19:20
  Speaker 2: they get filtered, or when they bounce off the things
• 19:22
  Speaker 2: they get some of them make it out of the
• 19:26
  Speaker 2: bounds and they sometimes hit our eyes, and then that's
• 19:29
  Speaker 2: our experience of seeing things.
• 19:30
  Speaker 1: Yeah, exactly, and also our eyeballs do some filtering, right
• 19:33
  Speaker 1: to be experienced, the photon has to make it into
• 19:36
  Speaker 1: the pupil and then through the lens and then all
• 19:39
  Speaker 1: the way to the back of the retina where it
• 19:41
  Speaker 1: can actually be interacted with. That's where there are these
• 19:44
  Speaker 1: proteins which either turn on or turn off based on
• 19:47
  Speaker 1: the frequency of light. So you have these like array
• 19:50
  Speaker 1: of sensors in the back of your eyeballs which can
• 19:53
  Speaker 1: detect photons.
• 19:55
  Speaker 2: Did you look into how that works? Like there's a
• 19:58
  Speaker 2: molecule on the surface of the receptor there and then
• 20:02
  Speaker 2: it just gets activated and it wiggles, and then how
• 20:04
  Speaker 2: does that? Does it release a chemical or does it
• 20:08
  Speaker 2: create an action potential? How does it work?
• 20:10
  Speaker 1: Yeah, it's actually really amazing. It's like a little machine
• 20:13
  Speaker 1: and it actually changes the protein's configuration when it absorbs
• 20:17
  Speaker 1: the photon. It flips like almost a physical switch on
• 20:20
  Speaker 1: this chemical to change its configuration and that adds energy
• 20:24
  Speaker 1: to it and then that's picked up by the optic nerve.
• 20:27
  Speaker 1: It's really kind of amazing chemistry. And you have these things.
• 20:31
  Speaker 1: They're scattered all over the back of your eye. Of course,
• 20:33
  Speaker 1: people know there's two different kinds. There's rods, which basically
• 20:36
  Speaker 1: give you black and white vision. They're sensitive across the spectrum.
• 20:39
  Speaker 2: Wall what does that mean, Like any photon of any
• 20:42
  Speaker 2: frequency will activate them or not.
• 20:44
  Speaker 1: It's not exactly flat across the spectrum. But essentially, yes,
• 20:47
  Speaker 1: they're not very frequency specific, they're not choosy. They're very
• 20:50
  Speaker 1: very sensitive. Yeah, they're not choosy, but they're very good
• 20:53
  Speaker 1: at picking out photons. They're much better than the cones.
• 20:55
  Speaker 1: So they're good for like at night, is there a
• 20:58
  Speaker 1: predator there or not? You don't really care if to
• 21:00
  Speaker 1: red or green. You just want to know if it's
• 21:02
  Speaker 1: something there.
• 21:03
  Speaker 2: Basically gives the sense of like brightness or darkness.
• 21:06
  Speaker 1: Yes, exactly, it's like black versus white. But then you
• 21:09
  Speaker 1: have these other sensors, these cones. There's three different kinds
• 21:12
  Speaker 1: of them. You have like six or seven million in
• 21:14
  Speaker 1: the back of each eyeball, and most of them are
• 21:16
  Speaker 1: actually concentrated in a tiny little spot in the retina
• 21:20
  Speaker 1: near the center of your vision. So you have like
• 21:23
  Speaker 1: color vision near the center of your eyeball, but mostly
• 21:26
  Speaker 1: black and white in the rest, which is fascinating and
• 21:29
  Speaker 1: each of these cones responds to a different frequency of light,
• 21:32
  Speaker 1: so it has like a protein on it, and a
• 21:34
  Speaker 1: different protein for each kind. You have three different kinds,
• 21:37
  Speaker 1: and those proteins are tuned to flip or to not
• 21:40
  Speaker 1: flip for different frequencies of light. So one of them
• 21:43
  Speaker 1: mostly flips on for blue light, another one mostly flips
• 21:47
  Speaker 1: on for green, another one flips on for like yellowish red.
• 21:50
  Speaker 2: Light, and it so did they sort of ignore the
• 21:54
  Speaker 2: other frequencies.
• 21:55
  Speaker 1: They don't exactly ignore them, right, They're not in very
• 21:58
  Speaker 1: narrow bands. So one of them does peak in the blue,
• 22:01
  Speaker 1: and one peaks in the green, and one peaks in
• 22:03
  Speaker 1: the red. If you imagine, like, what's the probability for
• 22:05
  Speaker 1: this protein to flip based on the frequency of light, Well,
• 22:08
  Speaker 1: the blue one will almost always flip for a blue one,
• 22:11
  Speaker 1: but it'll sometimes flip for a green one, though not
• 22:13
  Speaker 1: as reliably. And the red one will always flip for
• 22:16
  Speaker 1: a red one, and sometimes for a green one, and
• 22:18
  Speaker 1: occasionally even for a blue one. So they're a little
• 22:21
  Speaker 1: bit overlapping. They're not like perfect bands.
• 22:24
  Speaker 2: Right, They're fuzzy. They can each will react to a
• 22:26
  Speaker 2: certain range of frequencies where those freagancies are centered. It
• 22:29
  Speaker 2: kind of depends on the type of cone.
• 22:31
  Speaker 1: Yeah, exactly. And so you have three of these, each
• 22:33
  Speaker 1: of which are centered at different places in the spectrum.
• 22:36
  Speaker 1: And then what your brain does is interpret the signals
• 22:39
  Speaker 1: from these cones to figure out, oh, how blue was it. So,
• 22:43
  Speaker 1: for example, if you get a signal only from blue
• 22:45
  Speaker 1: cones and nothing from the red and the green one,
• 22:48
  Speaker 1: then you're like, Okay, that must have been pretty blue
• 22:51
  Speaker 1: in order to signal the blue ones and not signal
• 22:53
  Speaker 1: the other ones. But if you get something that signals
• 22:55
  Speaker 1: the blue one and the green one and not the
• 22:57
  Speaker 1: red one, then you're like, okay, it was blue green.
• 23:00
  Speaker 1: And so you can sort of triangulate where it is
• 23:02
  Speaker 1: on the spectrum by the ratios of how these things react.
• 23:07
  Speaker 2: Interesting. All right, Well let's get to this idea that
• 23:10
  Speaker 2: maybe there are colors that are impossible for us to
• 23:13
  Speaker 2: see even with our rods and cones. So let's dig
• 23:16
  Speaker 2: into that. But first let's take a quick break. All right,
• 23:32
  Speaker 2: we're talking about color today, hopefully not getting too off color.
• 23:36
  Speaker 1: Depends on if you think philosophy is off color or not.
• 23:38
  Speaker 1: What is the color of philosophy?
• 23:41
  Speaker 2: WHOA, Well, that's getting a little purple there.
• 23:46
  Speaker 1: I didn't mean to ask a lavender question.
• 23:48
  Speaker 2: Well you don't have to yellow it, Daniel. All right, Well,
• 23:52
  Speaker 2: we're talking about how we experience light, and so we
• 23:55
  Speaker 2: know that light are photons. They come in different frequencies.
• 23:59
  Speaker 2: There are frequencies from here to infinity. But our eyes
• 24:03
  Speaker 2: have these sensors that can detect photons around certain frequencies,
• 24:07
  Speaker 2: and those are the ones that generally we would associate
• 24:10
  Speaker 2: as red, green, and blue rightb RGB.
• 24:14
  Speaker 1: And it's fascinating that here we've transformed, as you said,
• 24:18
  Speaker 1: an infinite one dimensional spectrum. Photons could be anywhere along
• 24:21
  Speaker 1: the spectrum. So now sort of this three D spectrum
• 24:24
  Speaker 1: RGB right, and the color that we perceive depends in
• 24:28
  Speaker 1: principle on the photon, but really it depends on the
• 24:31
  Speaker 1: signals from these neurons, which is in this three D
• 24:34
  Speaker 1: space of red, green, or blue. You get these signals
• 24:38
  Speaker 1: from these neurons, and once you experience is in your mind,
• 24:41
  Speaker 1: it is just an interpretation of this point in this
• 24:45
  Speaker 1: three dimensional RGB space.
• 24:48
  Speaker 2: I guess maybe a question you could ask is like,
• 24:50
  Speaker 2: why are we doing it this way? Why are we
• 24:51
  Speaker 2: seeing the world this way? Why don't we just why
• 24:53
  Speaker 2: didn't evolution come up with this answer that can just
• 24:55
  Speaker 2: tell you what the frequency of light is.
• 24:58
  Speaker 1: That's fascinating question. And there are some close based on
• 25:00
  Speaker 1: the variety of the way the color perception works in
• 25:04
  Speaker 1: the animal kingdom, Like we know that we have these
• 25:07
  Speaker 1: three sensors, but there's nothing special about three. Like people
• 25:10
  Speaker 1: think of RGB as the fundamental basis of color, but
• 25:13
  Speaker 1: it's just so the way the human eye works. There
• 25:15
  Speaker 1: are critters out there with like eleven different sensors. The
• 25:18
  Speaker 1: mantis shrimp, I think has like fourteen, and there are
• 25:22
  Speaker 1: and there are species out there that can see a
• 25:24
  Speaker 1: broader range or a narrower range of colors, just depends
• 25:28
  Speaker 1: on what's more efficient. The fascinating thing is that the
• 25:31
  Speaker 1: more sensors you have, the better you are typically of
• 25:34
  Speaker 1: being able to tell the difference between shades. So if
• 25:37
  Speaker 1: you like really need to know the difference between dark
• 25:39
  Speaker 1: green and light green, you might evolve more sensors or
• 25:43
  Speaker 1: more sort of like processing power to be able to
• 25:46
  Speaker 1: distinguish these signals.
• 25:48
  Speaker 2: Yeah, I guess the more sensors you have, like kind
• 25:50
  Speaker 2: of like posts you put in the frequency spectrum, the
• 25:53
  Speaker 2: more you can tell things apart.
• 25:55
  Speaker 1: Sometimes, like the mantis shrimp is famous for having like
• 25:58
  Speaker 1: fourteen different sensors. You might think, wow, they must see
• 26:01
  Speaker 1: the world in really vivid color, but they have very
• 26:03
  Speaker 1: very few neurons to back it up behind that, so
• 26:06
  Speaker 1: it's like they have really really good hardware but terrible software.
• 26:10
  Speaker 1: So they might actually not experience more colors than we do,
• 26:14
  Speaker 1: like the actual experience of a Manti strip. Who can
• 26:16
  Speaker 1: never know right until we write that paper. But I
• 26:19
  Speaker 1: think it takes both complex hardware and complex software to
• 26:23
  Speaker 1: experience a broad variety of colors.
• 26:25
  Speaker 2: I'm sure those fourteen centers are doing something right, like
• 26:27
  Speaker 2: it's letting it discriminate a certain specific colors or certain
• 26:31
  Speaker 2: specific patterns. But maybe after that, it's just not like
• 26:35
  Speaker 2: the man district is not appreciating the color.
• 26:39
  Speaker 1: It depends a lot on the processing, right. You get
• 26:41
  Speaker 1: these signals if you have very crude responses to them,
• 26:44
  Speaker 1: very crude like neural networks behind them to help you
• 26:47
  Speaker 1: know how to respond to them, very wide bins in
• 26:49
  Speaker 1: your response, for example, you could be wasting a lot
• 26:52
  Speaker 1: of that information.
• 26:53
  Speaker 2: You know.
• 26:53
  Speaker 1: Imagine you have like a super excellent microphone and then a
• 26:57
  Speaker 1: terrible cable to store it in very low fidelity file
• 26:59
  Speaker 1: format could be very lossy. This is all very very speculative,
• 27:03
  Speaker 1: of course, and there's experiments going on to try to
• 27:05
  Speaker 1: understand what mentis shrimp experience. But there are some humans
• 27:09
  Speaker 1: that have more than three cones. They're called tetra worlds. Yeah,
• 27:14
  Speaker 1: like mutants, Yes, mutants exactly, But there are people have
• 27:21
  Speaker 1: four different kinds of cones. When I first heard of that,
• 27:23
  Speaker 1: I thought, WHOA, they must have a fourth color.
• 27:27
  Speaker 2: How does that happen? Like they have a mutation that
• 27:29
  Speaker 2: produces a whole different fourth kind of cone.
• 27:32
  Speaker 1: Yeah, they're very rare. Then you can spot them, not
• 27:34
  Speaker 1: because they see a different color we think. It's not
• 27:37
  Speaker 1: like there's a fourth color that adds to RGB that
• 27:40
  Speaker 1: they can experience that we can't. It's just that they
• 27:43
  Speaker 1: tend to be better discriminating between colors, so like they
• 27:47
  Speaker 1: might pass a color blindness test that the rest of
• 27:50
  Speaker 1: us would fail. If you put like a really really
• 27:53
  Speaker 1: subtle difference between the greens and the blues, for example,
• 27:56
  Speaker 1: they might pick something out that other people can't.
• 27:59
  Speaker 2: You put like a Stamp athlete next to a Harvard athlete,
• 28:02
  Speaker 2: and you'd ask them like which one is which You'd
• 28:05
  Speaker 2: be like, wait, what, they're the same? They just look red.
• 28:07
  Speaker 2: But you know, maybe a more discerning person might say,
• 28:09
  Speaker 2: oh no, that's a crimson, and then the other one's
• 28:13
  Speaker 2: like a wine red.
• 28:14
  Speaker 1: Junior college red. Yeah exactly. Yeah, yeah, way to come
• 28:17
  Speaker 1: up with an example that's really relatable, I'm suing a
• 28:20
  Speaker 1: lot of people have really struggled with their things.
• 28:22
  Speaker 2: I mean, if you put a banana slug next one
• 28:29
  Speaker 2: and eater, is it the same yellow or not?
• 28:32
  Speaker 1: You know, that's actually a really fun question because all
• 28:35
  Speaker 1: the University of California campuses are blue and gold, but
• 28:38
  Speaker 1: they all have different shades of gold.
• 28:41
  Speaker 2: Now, which one is more relatable? To exclude people who
• 28:44
  Speaker 2: don't live in California, or to exclude people who've never
• 28:47
  Speaker 2: heard of Stanford and Harvard?
• 28:49
  Speaker 1: I don't know. Let's hear from the listeners.
• 28:53
  Speaker 2: They're gonna be like, you excluded everyone.
• 28:58
  Speaker 1: Anyway. It's fascinating because the biological transformation of these photons
• 29:04
  Speaker 1: into optic signals puts us sort of like a distance
• 29:07
  Speaker 1: from the actual photon. Like what you're experiencing in your
• 29:10
  Speaker 1: mind is reaction to the optic nerve signals, not the
• 29:13
  Speaker 1: photon directly.
• 29:14
  Speaker 2: Well, it lands in your cone and then the cone
• 29:16
  Speaker 2: generates the signal that then gets transmitted to your brain.
• 29:20
  Speaker 1: Yeah, exactly what you mean. But you could simulate that
• 29:22
  Speaker 1: signal without the photon, right, You create that same signal
• 29:25
  Speaker 1: the optic nerve somehow without the photon, sort of the
• 29:28
  Speaker 1: matrix style. You can experience that color without a photon,
• 29:31
  Speaker 1: of that energy actually arriving on your optic nerve, and
• 29:35
  Speaker 1: it tells you that. Like we say, photons have color,
• 29:37
  Speaker 1: we call them red photons or blue photons, but that's
• 29:40
  Speaker 1: not really accurate. The photons themselves don't have a color.
• 29:42
  Speaker 1: The color is in your mind. The photons have an energy,
• 29:46
  Speaker 1: to have a frequency, to have a wavelength. The color
• 29:48
  Speaker 1: is just like your experience of the photon.
• 29:51
  Speaker 2: Well, I mean, it's our brains trying to figure out
• 29:54
  Speaker 2: what that frequency is. It just that we came up
• 29:56
  Speaker 2: with a name for things like, oh, that's thirty point seven.
• 29:59
  Speaker 2: Her have a prequancy light. We will call that yellow.
• 30:03
  Speaker 2: Why not because we don't have decimal numbers back in
• 30:07
  Speaker 2: the day.
• 30:07
  Speaker 1: It's our brain trying to give us what it thinks
• 30:10
  Speaker 1: is a useful experience or what evolution has proven to
• 30:12
  Speaker 1: be a useful experience, the way that, like touching something
• 30:16
  Speaker 1: hot gives you a painful experience, turns out to be useful.
• 30:20
  Speaker 1: Having these different experiences in your mind for these different
• 30:23
  Speaker 1: bands of frequencies turns out to be useful. But what's
• 30:26
  Speaker 1: fascinating is a sort of philosophical question of like, where
• 30:29
  Speaker 1: do these experiences themselves come from? And are they the same?
• 30:33
  Speaker 1: You know, you put two people in black and white
• 30:35
  Speaker 1: rooms and raise them without color and describe colors to them.
• 30:39
  Speaker 1: Could they come out of that room and identify red
• 30:41
  Speaker 1: versus blue versus green? Or is it purely captured in
• 30:45
  Speaker 1: the innate experience and can never be described in any
• 30:48
  Speaker 1: other terms. There are fascinating philosophical questions.
• 30:52
  Speaker 2: I think it has been proven our brains have evolved to
• 30:55
  Speaker 2: react to certain colors in certain ways, right, Like green
• 30:58
  Speaker 2: usually has a calming effect, Red has a certain sort
• 31:01
  Speaker 2: of anxiety raising effect. Right is that kind of what
• 31:03
  Speaker 2: you mean, like our brains are cute to react to
• 31:06
  Speaker 2: startain colors or what.
• 31:07
  Speaker 1: I'm not familiar with those studies, though imagine it's probably
• 31:10
  Speaker 1: is true that there are emotional responses to various colors.
• 31:13
  Speaker 1: But I mean, like the actual experience of the color,
• 31:15
  Speaker 1: Like the red that you feel in your mind is
• 31:18
  Speaker 1: just an experience in your mind the way pain is right,
• 31:21
  Speaker 1: Pain is like a reaction to heat, to damage, to temperature.
• 31:25
  Speaker 1: Red is a reaction to certain frequencies of light hitting you.
• 31:28
  Speaker 1: But the light itself is not red, the way that,
• 31:30
  Speaker 1: like the heat from the burner, is not actually literally painful.
• 31:33
  Speaker 1: The pain is part of your experience of it.
• 31:36
  Speaker 2: Yeah, yeah, I guess, But I feel like maybe we're
• 31:38
  Speaker 2: sort of maybe confusing things by trying to get to philosophical.
• 31:42
  Speaker 2: It's basically just your brain trying to detect what's happening
• 31:45
  Speaker 2: in the world, right, Yeah.
• 31:46
  Speaker 1: It's your brain's interpretation of these signals. And you're right,
• 31:49
  Speaker 1: Getting philosophical does always confuse things because you end up
• 31:52
  Speaker 1: with questions you can't answer and you don't know if
• 31:55
  Speaker 1: they actually tat you anything.
• 31:56
  Speaker 2: So then let's get back to this topic of it.
• 31:58
  Speaker 2: Maybe that there's a color that it's impossible for us
• 32:01
  Speaker 2: to see or to make we're both.
• 32:04
  Speaker 1: Yeah. A few decades ago a theory developed about how
• 32:07
  Speaker 1: we experience color. It's actually slightly more complicated and actually
• 32:11
  Speaker 1: slightly simpler than what we just described. Instead of imagining
• 32:15
  Speaker 1: that you get like three signals red, green, and blue
• 32:20
  Speaker 1: actually the way.
• 32:20
  Speaker 2: That but I guess maybe just from a very basic
• 32:22
  Speaker 2: level of course, our colors we can see, like we
• 32:24
  Speaker 2: can't see light up up on the infrared, and we
• 32:27
  Speaker 2: can't see light down or up in the ultraviolet. Right, Like,
• 32:30
  Speaker 2: there's a whole range of light frequencies, infinite range of
• 32:34
  Speaker 2: light frequencies that were our eyes just don't detect, Like
• 32:38
  Speaker 2: they just go through our eyes or they hit our
• 32:40
  Speaker 2: eyes and don't activate it.
• 32:41
  Speaker 1: Right, Yeah, absolutely, there are lots of frequencies of light
• 32:44
  Speaker 1: that don't generate in the signal. I don't know if
• 32:46
  Speaker 1: those frequencies of light have a color though, right, color
• 32:49
  Speaker 1: is just our experience, and so you just don't assign
• 32:51
  Speaker 1: a color to those frequencies. So there are frequencies we
• 32:54
  Speaker 1: cannot see. I don't know if those frequencies have color.
• 32:57
  Speaker 2: What would you call a color?
• 32:59
  Speaker 4: Was it?
• 32:59
  Speaker 2: Like if we have like a visual spectrum, right, Like,
• 33:03
  Speaker 2: there's a range of frequencies that our eyes can detect,
• 33:06
  Speaker 2: and so let's call color the light that is within
• 33:09
  Speaker 2: that range, the frequency of the light within that range.
• 33:12
  Speaker 1: Yeah, I would say color is our response to frequencies
• 33:15
  Speaker 1: of light within that range.
• 33:16
  Speaker 2: Okay, I mean that sounds like an arbitrary definition. I
• 33:20
  Speaker 2: could also just posit colors the frequency of the light
• 33:23
  Speaker 2: that we can see, so.
• 33:24
  Speaker 1: That all works really well. If you think about individual
• 33:26
  Speaker 1: frequencies of light, it all makes sense. But you know,
• 33:29
  Speaker 1: we never see individual frequencies. You always see a mixture.
• 33:31
  Speaker 1: You see a little bit of this frequency, a little
• 33:33
  Speaker 1: bit of that frequency. And once we start thinking about
• 33:36
  Speaker 1: mixtures of frequencies, things get more complicated. And actually a
• 33:39
  Speaker 1: different theory of how we experience color emerged a few
• 33:43
  Speaker 1: decades ago. It's called opposing neuron theory. It says, instead
• 33:47
  Speaker 1: of having like a three dimensional space RGB red, green,
• 33:51
  Speaker 1: and blue one for each of these different kinds of cones,
• 33:54
  Speaker 1: actually we only really have two because we have opposing neurons.
• 33:59
  Speaker 1: That we have neus the fire more when light is
• 34:01
  Speaker 1: red and less when it's green. And we have another one,
• 34:05
  Speaker 1: a blue versus yellow one that fires more when things
• 34:07
  Speaker 1: are yellow and less when things are blue. So instead
• 34:10
  Speaker 1: of happening like three dimensional information, our nerves have figured
• 34:14
  Speaker 1: out a way to incorporate this in just two dimensions,
• 34:16
  Speaker 1: like a green versus red axis and a blue versus
• 34:19
  Speaker 1: yellow axis. It's still pulled out of the same cones,
• 34:23
  Speaker 1: but it's a little bit of processing there to like
• 34:25
  Speaker 1: convert it into this red versus green and blue versus yellow.
• 34:30
  Speaker 2: I think you're talking about what happens after it hits
• 34:32
  Speaker 2: your optic nerve and maybe after it goes up into
• 34:35
  Speaker 2: your like visual cortex, right, you're talking about like, you know,
• 34:38
  Speaker 2: maybe your brain or evolution said, you know, maybe we
• 34:40
  Speaker 2: don't need three signals to figure out what color thing
• 34:43
  Speaker 2: the banana is or whether that's a spotted leopard or not. Like,
• 34:48
  Speaker 2: maybe we can just instead of having three variables, maybe
• 34:50
  Speaker 2: we can just do with two variables, and maybe that's
• 34:52
  Speaker 2: more efficient and faster and just enough to survive.
• 34:56
  Speaker 1: Yeah, exactly. I'm not exactly sure where this happens, and
• 34:59
  Speaker 1: you know where the brain technically ends and the optic
• 35:02
  Speaker 1: nerve begins. But yeah, this is part of the processing
• 35:05
  Speaker 1: that happens in your brain. This is opposing neuron theory,
• 35:09
  Speaker 1: and that means something really interesting because it means there's
• 35:11
  Speaker 1: a little bit of a loss of information, and it
• 35:14
  Speaker 1: means that there are some colors which now cannot be
• 35:16
  Speaker 1: described in this two dimensional plane. For example, a mixture
• 35:20
  Speaker 1: of green and red. You have this one opposing neuron
• 35:23
  Speaker 1: which is supposed to fire more if it's red and
• 35:26
  Speaker 1: less if it's green. What does it do if you
• 35:29
  Speaker 1: send it red and green? Right? Does it fire more
• 35:32
  Speaker 1: for the red and fire less for the green. It's
• 35:35
  Speaker 1: an ore system. It can tell you whether this light
• 35:37
  Speaker 1: is red or is green. There's no response that that
• 35:40
  Speaker 1: neuron can make that says I see red and green.
• 35:44
  Speaker 2: Wouldn't it fire like somewhere in between? Like neurons and
• 35:47
  Speaker 2: code things by the frequency at which they, you know,
• 35:50
  Speaker 2: send signals, right, like little like Morse codes. So if
• 35:53
  Speaker 2: it's like doing red and for green, wouldn't like a
• 35:57
  Speaker 2: mixture give you something in between?
• 35:59
  Speaker 1: You can see a color that's between red and green,
• 36:01
  Speaker 1: But you can't see like intense red and green simultaneously.
• 36:05
  Speaker 2: Oh, you're talking about the intensity of things, not like
• 36:08
  Speaker 2: which frequencies are present.
• 36:09
  Speaker 1: It's also true if this is fairly dim. But what
• 36:11
  Speaker 1: you can see is a color between red and green. Right,
• 36:14
  Speaker 1: If you see like something on the spectrum that's between
• 36:17
  Speaker 1: red and green, it's like a yellow, then you can
• 36:19
  Speaker 1: see that, and the response of the neuron will be
• 36:22
  Speaker 1: between its response for red and for green. If you
• 36:25
  Speaker 1: shine pure green and pure red on it. It's supposed
• 36:27
  Speaker 1: to both trigger it and inhibit it, and it doesn't
• 36:29
  Speaker 1: know how to communicate that there's no place on its
• 36:32
  Speaker 1: response that means green and red.
• 36:35
  Speaker 2: Now, as you said, this is a theory, are there
• 36:39
  Speaker 2: experiments back it up? Or like, do we know where
• 36:41
  Speaker 2: in the brain this is happening.
• 36:43
  Speaker 1: We don't know where in the brain this is happening.
• 36:45
  Speaker 1: And there's a controversial set of experiments. People were like,
• 36:48
  Speaker 1: is it possible to see these things? What happens if
• 36:51
  Speaker 1: you put like strips of color near each other and
• 36:54
  Speaker 1: ask people to like focus on the line between them.
• 36:58
  Speaker 1: So they have these experiments that did originally in the
• 37:00
  Speaker 1: eighties where they put like strips of blue and strips
• 37:03
  Speaker 1: of yellow next to each other, or strips of red
• 37:05
  Speaker 1: and strips of green next to each other, and ask like,
• 37:08
  Speaker 1: what do you experience right at the edge? You know,
• 37:10
  Speaker 1: where you're seeing like red and green at the same time.
• 37:14
  Speaker 1: So there's this paper in eighties by these two guys,
• 37:16
  Speaker 1: Crane and the Piantanita, and they claim to see these
• 37:19
  Speaker 1: impossible colors. They ask people to describe what color they
• 37:22
  Speaker 1: were seeing at the boundary, and it was like indescribable,
• 37:26
  Speaker 1: and so this paper was really controversial for a long time.
• 37:29
  Speaker 1: And then there were experiments two decades later at Dartmouth
• 37:33
  Speaker 1: in the mid two thousands that sort of disputed these
• 37:36
  Speaker 1: results and said, like, hmm, maybe people are just seeing
• 37:39
  Speaker 1: sort of like an intermediate color. They're not simultaneously experiencing
• 37:43
  Speaker 1: what happens when you have red and green photons. It's
• 37:46
  Speaker 1: just sort of like hard to describe. So this controversy
• 37:49
  Speaker 1: in the literature about whether this theory is right. There
• 37:52
  Speaker 1: are other theories of how we experience color and whether
• 37:55
  Speaker 1: it's possible to see these colors in some way.
• 37:58
  Speaker 2: So what do you mean by possible colors? You're talking
• 38:01
  Speaker 2: about like combinations of color that we can experience, Yeah, exactly,
• 38:07
  Speaker 2: that maybe our optic nerves are picking up because they're
• 38:10
  Speaker 2: definitely picking up something, but we just because of the
• 38:12
  Speaker 2: way that our brains have maybe streamlined and gotten rid
• 38:16
  Speaker 2: of certain information that doesn't think it needs now we
• 38:18
  Speaker 2: have kind of blind spots in the color spectrum.
• 38:21
  Speaker 1: Yeah exactly. And I read a really fascinating paper that
• 38:24
  Speaker 1: suggested you might be able to experience this if you
• 38:26
  Speaker 1: can come up with a way to like differently trigger
• 38:30
  Speaker 1: different parts of your optic nerve. Like if you could
• 38:32
  Speaker 1: get some of these opposing neurons to respond to the
• 38:35
  Speaker 1: green light and some of them to respond to the
• 38:37
  Speaker 1: red light, then instead of all sending the same signal,
• 38:40
  Speaker 1: you'd have some sending the green signal and some sending
• 38:42
  Speaker 1: the red signal, both intensely, and then maybe your brain
• 38:46
  Speaker 1: would know how to interpret that, and we'd give you
• 38:48
  Speaker 1: this experience of this red green combination. That's one theory,
• 38:53
  Speaker 1: And people argue, like, maybe that's what was happening in
• 38:55
  Speaker 1: the eighty three experiments, that they somehow like parts of
• 38:59
  Speaker 1: it were triggering this part of your nerve and other
• 39:01
  Speaker 1: parts are experiencing other parts of the nerve. But yeah,
• 39:03
  Speaker 1: it's about these mixtures of colors that we can't see.
• 39:06
  Speaker 1: We can see all the pure colors, but these mixtures
• 39:08
  Speaker 1: of colors we can't see.
• 39:10
  Speaker 2: Well, I guess you would see them, you just wouldn't
• 39:12
  Speaker 2: be able to maybe tell them apart from some of
• 39:15
  Speaker 2: the primary colors.
• 39:16
  Speaker 1: Perhaps this is novel color, which is a mixture of
• 39:19
  Speaker 1: these two which we do not have an experience of.
• 39:22
  Speaker 1: Because we think that the sensory mechanisms and the optical
• 39:25
  Speaker 1: nerve processing can't carry the information to describe it. The
• 39:29
  Speaker 1: loss of information means there's no way to encode it
• 39:32
  Speaker 1: basically in those signals.
• 39:33
  Speaker 2: Now, do these impossible colors have a specific frequency or
• 39:38
  Speaker 2: would you call it a different color because it's a
• 39:40
  Speaker 2: mix of different frequencies.
• 39:42
  Speaker 1: Yeahs, see that's fascinating because we think about color as
• 39:45
  Speaker 1: associated with the frequency spectrum, right, and so pure frequencies
• 39:48
  Speaker 1: we think of as pure colors, and that makes sense.
• 39:51
  Speaker 1: But here we're talking about combinations of different frequencies, like
• 39:54
  Speaker 1: shooting red and green photons or blue and yellow photons
• 39:58
  Speaker 1: at you at the same time. And so that's why
• 40:01
  Speaker 1: I think it's helpful that separated the question of frequency
• 40:04
  Speaker 1: and color, because color is what you experience in your mind,
• 40:06
  Speaker 1: and it's not always connected to just one frequency. Like
• 40:10
  Speaker 1: this red green color, whatever it is, that would be
• 40:13
  Speaker 1: an experience in your mind, your brain's interpretation of seeing
• 40:16
  Speaker 1: both red frequency photons and green frequency photons at the
• 40:20
  Speaker 1: same time. You wouldn't experience red, you wouldn't experience green,
• 40:24
  Speaker 1: you'd experience some red green thing we don't have a
• 40:26
  Speaker 1: word for.
• 40:28
  Speaker 2: I guess it kind of goes back to the question
• 40:30
  Speaker 2: of like what is yellow like If we have sensors
• 40:33
  Speaker 2: that the tech red, blue, and green. What is yellow?
• 40:36
  Speaker 1: Yeah, if you just think about the spectrum, right, yellow
• 40:39
  Speaker 1: is the color that triggers the green and the red
• 40:42
  Speaker 1: about the same amount and doesn't trigger the blue.
• 40:46
  Speaker 2: Like there's a specific frequency that will do that, right,
• 40:48
  Speaker 2: I imagine mm hmm. Now you could call that frequency yellow.
• 40:51
  Speaker 2: But you can also kind of fool the eye into
• 40:54
  Speaker 2: thinking of yellow by mixing frequencies. That's kind of what
• 40:57
  Speaker 2: your TV and your phone screen do.
• 40:59
  Speaker 1: Yeah, this is specific frequency range that we know triggers
• 41:02
  Speaker 1: the experience of yellow in your minds five hundred and
• 41:04
  Speaker 1: seventy to five and eighty animeters. Absolutely, and you know
• 41:09
  Speaker 1: the same way that there's like a cyan and there's
• 41:11
  Speaker 1: a purple. You don't have a special cone for these things.
• 41:14
  Speaker 1: There are brain creating an experience for this whole range
• 41:17
  Speaker 1: of possible signals that it's getting.
• 41:20
  Speaker 2: Right, And you can sort of fold it into thinking
• 41:22
  Speaker 2: of yellow by mixing frequencies, right. I mean like in
• 41:26
  Speaker 2: your TV or your phone screen, there's only like three
• 41:29
  Speaker 2: kinds of LEDs in it, right, There's red, green, and
• 41:32
  Speaker 2: yellow ones. And so when you look at something yell
• 41:34
  Speaker 2: on your phone, it's not actually shooting yellow light, shooting
• 41:37
  Speaker 2: some combination of red, blue, and green that's making your
• 41:40
  Speaker 2: brain think it's yellow. But there's also a frequency that
• 41:43
  Speaker 2: wouldn't trigger that same Oh that's yellow. Anyways. The point
• 41:47
  Speaker 2: is that there are combinations of frequencies that maybe our
• 41:51
  Speaker 2: brains are not designed to like trigger your consciousness of them.
• 41:56
  Speaker 1: Yeah, exactly. There should be a unique experience for those combinations,
• 42:01
  Speaker 1: but the brain has nobody interpret it because it doesn't
• 42:03
  Speaker 1: get a unique signal for those combinations. So we even
• 42:06
  Speaker 1: like developed a unique experience.
• 42:08
  Speaker 2: It's like you're blind to those colors kind of mm hmm, yeah,
• 42:12
  Speaker 2: like it just looks red to you. You're like Stanford,
• 42:13
  Speaker 2: Harvard the irvine. I don't know, mm, it could be
• 42:17
  Speaker 2: any athlete.
• 42:18
  Speaker 1: There's two other sort of ways to think about impossible
• 42:21
  Speaker 1: colors as well. There are colors that can't be generated
• 42:24
  Speaker 1: by any physical source, and then there's these things they
• 42:27
  Speaker 1: called chimerical colors.
• 42:30
  Speaker 2: Interesting. All right, let's get into those impossible to make
• 42:33
  Speaker 2: colors and dig into what that means. But first let's
• 42:37
  Speaker 2: take another quick break. Are we getting very colorful today?
• 42:53
  Speaker 2: Looking at all of the rainbow of ideas around the
• 42:57
  Speaker 2: concept of color and how we perceive it, and what
• 43:00
  Speaker 2: is a color anyway, and what color is your been
• 43:02
  Speaker 2: in it as well?
• 43:04
  Speaker 1: Hey that's a personal question, man.
• 43:06
  Speaker 2: WHOA Well, you just got really really purple there. I
• 43:10
  Speaker 2: wasn't even thinking about that. I see what's on your mind,
• 43:14
  Speaker 2: Daniel m lunch. Oh that's even racier.
• 43:21
  Speaker 1: Let's steer back to physics.
• 43:22
  Speaker 2: But we talked about how maybe there are combinations the
• 43:24
  Speaker 2: frequencies of light that we can't see, because really color
• 43:28
  Speaker 2: is our experience of how light hits her eye and
• 43:31
  Speaker 2: sometimes sets of specific frequency maybe that's sometimes that's a
• 43:33
  Speaker 2: combination or the absence of certain frequencies. So color is
• 43:36
  Speaker 2: a complicated thing. But there are maybe combinations of frequencies
• 43:41
  Speaker 2: that we our brains are just not equipped to deteg
• 43:44
  Speaker 2: unless maybe you're maybe trained to see them, or maybe
• 43:47
  Speaker 2: you're one of these people born with extra sensors.
• 43:49
  Speaker 1: Right, Yeah, it could be. And in the end, we
• 43:51
  Speaker 1: don't know what other people experience. We can just ask
• 43:55
  Speaker 1: them to compare previous experience to current experience or to
• 43:58
  Speaker 1: some references, but we can't, you know, cross correlate across brains.
• 44:02
  Speaker 1: We don't know how to extract from inside the brain
• 44:05
  Speaker 1: the actual encoding of these things and interpret it in
• 44:08
  Speaker 1: any sort of objective way map from one brain to another.
• 44:12
  Speaker 1: In the end, it's frustrating, but we can try to
• 44:15
  Speaker 1: reverse engineer the system and think about ways to experience
• 44:18
  Speaker 1: like weird colors or things that we can't experience. That's
• 44:22
  Speaker 1: a lot of fun. And the system, the way it works,
• 44:24
  Speaker 1: because it has these overlapping responses, also creates these things
• 44:28
  Speaker 1: called imaginary colors, colors not that we can't experience, but
• 44:32
  Speaker 1: that no physical source could generate.
• 44:34
  Speaker 2: Well, yeah, I think that's a question that I have
• 44:37
  Speaker 2: from the beginning. Are there colors that are impossible to make?
• 44:40
  Speaker 2: But I guess to be clear, all colors are possible
• 44:43
  Speaker 2: in the universe, right, Like you can always stretch light
• 44:47
  Speaker 2: to be a certain color infinitely with infinite precision in
• 44:50
  Speaker 2: the universe.
• 44:51
  Speaker 1: Right, Yes, all frequencies of light can exist out there
• 44:54
  Speaker 1: in the universe. But remember color is our experience in
• 44:57
  Speaker 1: the mind, and it's this interpretation of the the red, green,
• 45:00
  Speaker 1: and blue cones and then perhaps through these opposing neurons.
• 45:04
  Speaker 1: But because those things overlap, there's a question of like
• 45:06
  Speaker 1: what would happen if you only triggered the green neuron
• 45:11
  Speaker 1: right now, the green neuron and the red neuron are
• 45:13
  Speaker 1: almost overlapping. They're almost identical, Like there's a very small
• 45:16
  Speaker 1: shift between them. So any physical photon that hits your
• 45:20
  Speaker 1: eyeball that triggers the green is very likely going to
• 45:23
  Speaker 1: trigger also some red ones. So you shoot like pure
• 45:26
  Speaker 1: green light at somebody's eyeball, some of those red cones
• 45:30
  Speaker 1: are also going to get triggered.
• 45:31
  Speaker 2: Right because I think what we said before is that
• 45:33
  Speaker 2: our cones are not perfect, right, Like, they don't just
• 45:36
  Speaker 2: respond to one frequency. They respond to a range of frequencies,
• 45:39
  Speaker 2: and in our eyes, those ranges kind of overlap, So
• 45:43
  Speaker 2: there are some frequencies that will activate both yes.
• 45:46
  Speaker 1: And the red and the green in particular are very
• 45:48
  Speaker 1: close to each other. They respond almost the same way
• 45:50
  Speaker 1: to different frequencies, and so like if you shoot something
• 45:53
  Speaker 1: right in the middle of the green, then the green
• 45:55
  Speaker 1: cone is always going to respond and the red cone
• 45:57
  Speaker 1: is going to respond. Like ninety percent of the time
• 46:00
  Speaker 1: was like further shifted down. But it makes you wonder,
• 46:03
  Speaker 1: like what would happen if you could somehow just tweak
• 46:06
  Speaker 1: the cones. Don't worry about the light you're shooting at
• 46:08
  Speaker 1: it just somehow get only the green cone to respond
• 46:12
  Speaker 1: without the red cone responding.
• 46:14
  Speaker 2: Like what would happen in your brain?
• 46:16
  Speaker 1: Yes, they call this hyper green, like the greeniest green
• 46:19
  Speaker 1: that you could experience without any pollution from the red.
• 46:23
  Speaker 1: In reality, it's essentially impossible to generate this using photons
• 46:27
  Speaker 1: because all these photons will also stimulate that red cone.
• 46:31
  Speaker 2: Oh you're talking about like it's an impossible experience of
• 46:34
  Speaker 2: that color.
• 46:35
  Speaker 1: We don't know that it's impossible. Like technically, if I
• 46:37
  Speaker 1: attached little electrodes to all the nerves behind the green
• 46:41
  Speaker 1: cones and stimulated them, then you would have this experience.
• 46:45
  Speaker 1: But I can't create a photon that would do the
• 46:47
  Speaker 1: same thing.
• 46:48
  Speaker 2: You mean, like, you can't create a photon that will
• 46:50
  Speaker 2: ignore the red cones, Yeah, and only hit the green
• 46:53
  Speaker 2: cone exactly. Well, less you could somehow aim them really well.
• 46:56
  Speaker 1: Yeah, exactly, super precise lasers in the back of your
• 46:59
  Speaker 1: eye only hit those green cones. So it's possible, then, well,
• 47:03
  Speaker 1: we think it's possible for it to happen. It's just
• 47:05
  Speaker 1: that there isn't a physical source we could make that
• 47:07
  Speaker 1: can do that. Yes, but that's the experience of hyper green.
• 47:11
  Speaker 2: Right right, And it's probably the color of like mountain dew,
• 47:17
  Speaker 2: or like if you took a green highlighter and like
• 47:18
  Speaker 2: paint is sear the back of your eyeball.
• 47:23
  Speaker 1: Yeah, so those are imaginary colors. Then there's another really
• 47:26
  Speaker 1: fun kind of color that you actually can experience.
• 47:29
  Speaker 2: But I mean it's not just green, right, and it's
• 47:31
  Speaker 2: like all of them right, Like, it's probably possible to
• 47:33
  Speaker 2: create a hyper blue or a hyper red.
• 47:35
  Speaker 3: Mm hm.
• 47:36
  Speaker 1: It's trickier with green and red because those two response
• 47:40
  Speaker 1: curves are basically on top of each other, so it's
• 47:43
  Speaker 1: harder to separate. Blue is further away, so it's possible
• 47:45
  Speaker 1: to experience a purer blue than it is red or green.
• 47:49
  Speaker 1: But in principle, yes, these same things are true. Even
• 47:52
  Speaker 1: blue photons will stimulate a fraction of the green and
• 47:55
  Speaker 1: red cones.
• 47:57
  Speaker 2: All right, So that's one kind of impossible color. You said,
• 48:00
  Speaker 2: there's another kind.
• 48:01
  Speaker 1: There's another category. These are called chimerical colors. These are
• 48:06
  Speaker 1: colors you experience if you change the way that your
• 48:09
  Speaker 1: cones respond. Remember, these are little biological machines and they
• 48:13
  Speaker 1: can sort of get tired. You know that if you
• 48:15
  Speaker 1: look at a really bright light and then look away,
• 48:17
  Speaker 1: for example, you still see it, right, that's because your
• 48:20
  Speaker 1: cones are tired and they're responding differently. Now there's something
• 48:23
  Speaker 1: like residual effect there. So for example, if you stare
• 48:26
  Speaker 1: at like really bright yellow light, it sort tires out
• 48:29
  Speaker 1: these opposing neurons. Then if you close your eye or
• 48:33
  Speaker 1: you look at something really really black, then you see
• 48:35
  Speaker 1: this blue response. There's no blue there. You're seeing a
• 48:39
  Speaker 1: reaction to tiring out your blue yellow neurons. And so
• 48:43
  Speaker 1: what you see is this super dark blue, this blue
• 48:47
  Speaker 1: that you otherwise could not experience because to experience it,
• 48:50
  Speaker 1: you'd need to receive a bunch of blue photons and
• 48:52
  Speaker 1: that would make it brighter. So you see this like
• 48:55
  Speaker 1: impossibly dark blue.
• 48:57
  Speaker 2: Whoa couldn't you just sit in a room and shoot
• 49:01
  Speaker 2: blue photons at my eyeball?
• 49:02
  Speaker 1: You could do that, but then receiving those photons would
• 49:05
  Speaker 1: create an experience of a brighter blue, and if you
• 49:07
  Speaker 1: dial it down eventually you just wouldn't see anything. You
• 49:09
  Speaker 1: just see black. So this is like a blue you
• 49:12
  Speaker 1: can experience without receiving any photons.
• 49:15
  Speaker 2: Right, because you're basically doing the same thing as these
• 49:17
  Speaker 2: imaginary colors, right, you're sort of like knocking out your
• 49:20
  Speaker 2: perception of certain rods and cones right exactly.
• 49:24
  Speaker 1: And this is actually pretty easy to do. You just
• 49:27
  Speaker 1: go to like Wikipedia and google chimerical colors. They have
• 49:30
  Speaker 1: these templates, and you like staring a yellow dot and
• 49:32
  Speaker 1: then look at a black field and you can see
• 49:34
  Speaker 1: this blue which is different from just like a really
• 49:37
  Speaker 1: really dark blue. It's fascinating. It's called sticky and blue.
• 49:40
  Speaker 2: Whea, it's wild to think that, Like, if I'm just
• 49:43
  Speaker 2: staring at something yellow, like my brain and my eyeballs
• 49:46
  Speaker 2: and brains are constantly going yellow yellow, yellow, yell ye yellow,
• 49:50
  Speaker 2: and eventually just like I give up, forget it.
• 49:55
  Speaker 1: Yeah, then they're tired, and then the blue one's out right,
• 49:58
  Speaker 1: and then they're sort of like leaning or they're biased
• 50:00
  Speaker 1: against it. They're like exhausted, the yell the like, don't
• 50:02
  Speaker 1: show me any more yellow. We're leaning blue for a while,
• 50:05
  Speaker 1: and they're basically sending you blue information even though there's
• 50:08
  Speaker 1: nothing there. And so because there's no brightness to it,
• 50:11
  Speaker 1: but you're getting blue, your brain is like, well, I
• 50:14
  Speaker 1: got to give you something blue, but there's no brightness there,
• 50:16
  Speaker 1: So what do we do. Let's make the darkest blue
• 50:18
  Speaker 1: we can. So it's a very deep blue.
• 50:21
  Speaker 2: Does that mean that if I stare at a banana
• 50:23
  Speaker 2: long enough, it'll eventually look blue.
• 50:26
  Speaker 1: I think it means if you stare a banana long
• 50:28
  Speaker 1: enough and close your eyes, you'll see an impossibly blue banana.
• 50:32
  Speaker 2: I guess you won't see it because you won't be
• 50:34
  Speaker 2: like experiencing photons from the banana. It'll be like sort
• 50:37
  Speaker 2: of this lingering memory in your visual cortex of a
• 50:40
  Speaker 2: blue banana.
• 50:41
  Speaker 1: Yeah, you'll be experiencing a deep blue banana even though
• 50:44
  Speaker 1: you're not getting blue photons from the banana.
• 50:46
  Speaker 2: From the banana, Yeah, yeah, I guess it's all because
• 50:51
  Speaker 2: we have this kind of flawed bio logical machinery that's
• 50:54
  Speaker 2: trying to interpret with the frequency that we see in
• 50:57
  Speaker 2: the world. But maybe through revolution, it's done it in
• 50:59
  Speaker 2: a week way where you have these weird effects right
• 51:02
  Speaker 2: where we can see certain combinations or you know, we
• 51:05
  Speaker 2: see residual colors.
• 51:07
  Speaker 1: Yeah, all of these colors in the end are brain's
• 51:09
  Speaker 1: interpretation of these signals, signals that are typically generated by
• 51:13
  Speaker 1: this experience or that experience. Back for in the corners
• 51:16
  Speaker 1: of this and the limitations of it, we can try
• 51:18
  Speaker 1: to get some understanding of what it means to see
• 51:21
  Speaker 1: color what it tells us about what's happening out there
• 51:23
  Speaker 1: in the universe.
• 51:25
  Speaker 2: Because I guess you know, as physicists or as scientists,
• 51:28
  Speaker 2: we can think about all the different frequencies of light.
• 51:30
  Speaker 2: But maybe if you're like a simple creature, you don't
• 51:33
  Speaker 2: need to know all that information, Like you don't need
• 51:35
  Speaker 2: to know whether something's ten point seven herds. You just
• 51:37
  Speaker 2: need to know, like, is this thing going to eat
• 51:40
  Speaker 2: me or not? That's in front of me? Is it red?
• 51:42
  Speaker 2: Is it the red kind that's going to eat me?
• 51:43
  Speaker 2: Or is it the blue kind that's going to not
• 51:45
  Speaker 2: eat me?
• 51:45
  Speaker 1: Yeah, exactly, And that's why some bees can see into
• 51:48
  Speaker 1: the ultraviolet because they have to despot the right kind
• 51:51
  Speaker 1: of flower. For example. That's probably why manti strimp have
• 51:54
  Speaker 1: super impressive hardware for ultrafast processing of this color and
• 51:57
  Speaker 1: then like mostly waste that information because the don't really
• 52:00
  Speaker 1: need to know specifically, they just needed fast processing.
• 52:04
  Speaker 2: Now, if a manta shrimp looked at a banana, would
• 52:06
  Speaker 2: it think it's a banana?
• 52:08
  Speaker 1: That's another philosophy of paper I want.
• 52:10
  Speaker 2: To write over to think, Oh, that's a nice digim
• 52:13
  Speaker 2: blue banana.
• 52:15
  Speaker 1: What is it like to be a manta strip eating
• 52:17
  Speaker 1: a banana.
• 52:17
  Speaker 2: Nobody knows that's the right feel. I'm pretty sure nobody
• 52:20
  Speaker 2: has published that paper.
• 52:24
  Speaker 1: I'm going to get on it.
• 52:28
  Speaker 2: All right. Well, the interesting discussion here about what color
• 52:31
  Speaker 2: is and what we can perceive. And you know, it
• 52:33
  Speaker 2: has a physical basis, but our brains the way it's evolved,
• 52:38
  Speaker 2: don't experience maybe the world the way physics has built it.
• 52:42
  Speaker 1: And it's important to remember that our experience in the
• 52:44
  Speaker 1: universe is always one step divorced from the reality of
• 52:47
  Speaker 1: the universe, which is, in the end, our interpretation of
• 52:50
  Speaker 1: a model we are building in our brain. Our a
• 52:53
  Speaker 1: direct experience is what we actually can count on. Everything
• 52:56
  Speaker 1: else is our interpretation.
• 52:58
  Speaker 2: Yeah, and if that makes you red with anger or
• 53:01
  Speaker 2: blue with sadness, just close your eyes.
• 53:03
  Speaker 1: Don't yellow at us.
• 53:04
  Speaker 2: Yeah, imagine a more beautiful universe of colors. All right, Well,
• 53:10
  Speaker 2: we hope you enjoyed that. Thanks for joining us. See
• 53:12
  Speaker 2: you next time.
• 53:18
  Speaker 1: For more science and curiosity, come find us on social
• 53:20
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• 53:28
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