Neil deGrasse Tyson Explains How We See Colors

chuck i gotta i got something tight my color oh oh you know what neil i'm sorry but this conversation won't work because i don't see color she so that's just who i am i'm sorry okay you know you might want to go find some other person tell your racist tale too so uh color is a huge subject and it's way more than i can cover in this uh short video but a couple of things i just want you to know that we in my my people my astrophysics community we think about color all the time yeah that's why i kind of noticed that no we can we can it's one of the bits of information you get from an object at a distance because you can't go there i thought you were talking about every time we go somewhere you're the only black astrophysicist we've got a few more there's a few more there yeah okay go ahead um so uh so you can see bits of information that you're getting from an object that yeah exactly so so we can know how bright it is you can know where it is on the sky you can detect if it's moving and you can take its light and break it up into its spectrum into its rainbow and you can see how many different colors compose the light that you see because your eye doesn't break it up into the spectrum the way that the visor does jordy's visor in star trek next generation next generation yeah jordy sees all bands of light and all the entire spectrum which is a far more superior form of sight than what we have what we have we take light we it blends all into one sort of quote color image but there are ways to split it all apart in case something is revealing itself in one place and not another you can identify certain chemical features in an object all right that's not even why i'm i'm bringing this up i'm just saying we care and think a lot about the colors of things all right do you remember was it what color is the dress what was that thing that yes that was a um a youtube sensation not youtube okay it was a energy social media yeah okay so if you you would either see a blue dress or a gold dress but it was basically white supposedly yeah so so the point there is um i don't care what you see i care what it is so i would get a device out that measured how much light energy is coming from that dress in each of the bits of the spectrum and then i can quantify that and give a quantified exact measure of what the color is by the way the by the way the the internet websites do that callers are numbers okay yes it's a combination of numbers and that's the color i don't care what your your rods and cones and your retina are doing i don't care what your state of mind is i don't care if you're on lsd right that is a color and it's highly reproducible when you have it defined yeah that way that way you don't look at the gradient and say well that looks like it might be it it's like no it's 362. exactly exactly and so i can take a machine that's why the triumphs of science in modern times or since galileo you can measure the triumphs of science by how effectively it has replaced our physiological senses that we have been using before then so the telescope replaces and microscope replace our eyes to see far away things and small things and dim things and so so when you improve our senses you can make discoveries that we could not have made otherwise all right so that's why the color of the dress i just thought all right people you can fight over it but the scientists aren't fighting over the color of the dress all right so here's here's the point i want to make if you have an apple okay traditional apple what color is it red right okay so you say the apple is red let me hear you utter that sentence the apple is red okay so the very construction of that sentence implies that you are describing something intrinsic an intrinsic property of that apple right am i would i be wrong to say that it's making that what the apple possesses that possesses that call and the apple is round you can say things about it that are the properties of the apple okay here's a problem the only way you know the apple is red is because any red light that was in the white light that's illuminating it because white as shown by isaac newton is comprised of red orange yellow green blue indigo violet all right so so white light is composed of colors that's good because when you illuminate a scene with white light the red things reflect the red the blue things it's ripped it's it's using all of those colors in the rainbow to reveal what color they are okay that's why things are different colors in a room it's because your source of light is white that contains all those colors available to it okay so here's my point so white light is the color police i get it it's the crown i get it why is everything got to be the white light the white the blue white light is identifying all the other things is calling out your color calling the dog i got you kids calling out the white i'm sorry apple we had to pull you over you fit the description the description of what the somebody said they just saw something red that's all the red things that's all we needed that's all we needed it's already it was red uh gotta get that apple gotta go get that out it's red right yeah oh oh why i gotta be an apple [Laughter] so anyway all right so white white light is basically letting everything tell tell what it is by reflecting back to it can i watch okay so here comes the white light upon the apple okay okay sorry okay here it comes now the only reason why the apple is red is because it rejected the red that it was fed oh gotcha and absorbed all other colors colors in the spectrum so the rejection of the red is what we're seeing with our eyes correct that's why we call it red you call it red because that's not what it is right that's what it sent back to you right okay there's no red in around among that apple because the apple sent it back to you so the our very language that says the apple is red is logically flawed given what i'm telling you about light the apple is the orange yellow green blue indigo violet that's got stuck into the skin of the apple that's all absorbed into it that's what it is what it isn't is red as it inherent property wow wow wow it's weird now we can just accept just colloquially that a red object is red right we can just say that but i'm just saying if you go to the surface molecules of the red object there is no red there right it all got sent back to you that's amazing it's i love it because it's like you say um it's red is really the reference it's not what it is it's not what it is it's not what it is it's the reference wow so i just thought i'd tell you that and by the way if you have light that contains no red in it okay okay so you could take sort of um what they used to call black light so an ultraviolet light lights yeah or or very pure um a tube light like a um like do they still have the sodium lamps not the like the ones that are very yellow um the very yellow sodium lamps in the streets i don't know if they still have those not anymore but you you'll find them in like older places in older places right so what you do is take an apple and bring it up to that lamp you know what color the apple is no red and yellow no no it can't be red because the light source has no red no i'm saying what's that what's that what does that make so oh what no no i'm saying give it a light source that contains no red oh okay and bring apple into that light source oh i don't know what color it'll be the apple will be black black now see black see now it absorbs if it absorbs the colors then nothing's coming back to your eyes yeah well see that's how that works no here's the problem with that man okay don't know if i don't know don't nobody want no black apple don't tell nobody want no black apple okay now i'm just saying and you know i i i love listen i love black i love black i love being black i love you okay but you ain't in a black eyes i forgot when you say all the colors because i forgot black is the mixture of all colors no no black is the absence of the absence of all colors so yeah so if nothing no right all right white is all the colors black and light right together absolutely all colors gone right so if right that's what you would when you mix all the colors of light the fact that they make white is a little freaky to the artist it's a little freaky it is a little because when they mix paint it doesn't you don't get white but light mixed together you get white light right all those colors and if you colors are not coming to your eye the thing just becomes black there it is you know and it's so funny because i knowing that i know i'm still can't see the black apple because i and i know that black is the absence of color and i'm still trying to think like the only absence of code is the absence of light that's what i mean my point is white light hits the apple the apple looks red because it reflects only red light absorbed all the other colors now have a light source with no red right then it can't nothing's coming to you it's got to be black it's got this black what will happen in the absence of color with light you will not see anything because there's nothing coming back correct correct now i get it 100 oh by the way by the way the blue object will be blue next to it and then other things there's a yellow and there's a green i think the apple goes black right right that makes perfect sense let me take it up a notch i could not get my head around a black apple clearly you couldn't okay so now let's take it up a notch and we got to call it quits okay you ready go for it um i did this experiment in a telescope dome when you're in a telescope at night we have what's called night lighting which is very deep red lights that will still enable you to see the darkened skies it's called dark adapting because your eye goes through this you might notice um if you wake up in the middle of night and you put on the bathroom lights you're like well i can't you have to dark adapt all right and once you're dark adapted everything's fine we do this at the telescope dome so the telescope lights tend to be deep amber and sometimes deep red okay um i saw a can on the shelves there's a soda can and there was nothing written on it nothing the whole the whole can was red and it was like how can there be nothing what what what what turn on the lights guess what can it was uh what color was the the dark adapt yes it was a red okay so that would have been hmm trying to think which the whole can was red though the whole camera was red but i saw no detail on the camera no detail which is a pure red cam it's like what this is america everything we have has a surface with ads on it and names and products and everything so you know what it was coca-cola coca-cola can right is it coca-cola can why because the red on the coca-cola can reflects what the red light the red light the white on the coca-cola can reflects what um [Music] wow okay wait a minute oh the white light so right right no what is it white is wait a minute now i'm confused because he got me okay so so white light reflects all colors that's what i said all all of because it's white light but i'm not handing it all colors right your own oh that's i forgot we're in the dark adapt yes so there you go so the point is the red reflected the red light that's it the white reflected the red light right so there was no contrast between the two the two right and all of the printing on that can disappeared that's kind of cool very cool i like that very good we should send this to coca-cola now there's a friend of mine in college who uh in our physics class he was you were allowed to have a single sheet of handwritten notes a crib sheet basically for yourself but it had to fit on this single sheet of paper and so that was the rule so everyone prepared theirs and i saw this guy's sheet and you couldn't even read it it was like what did you do so what he did was he wrote in three different color pen inks on top of itself so it doesn't make a difference and then he brought the filters filters to and okay guys let me tell you something so you got three times as much information on it i would have given them an a just for that [Laughter] so chuck that's it uh there's so much more we can do five more color episodes but i just want to get it out there that an object isn't really its color please tell that to this one officer the police department please you have to turn this into a black lives matter episode okay fine please officer i just listened to dr neil degrasse tyson he said by the way officer you are wasting your time stopping me as a tax-paying white man because i absorbed all those because i absorbed all the colors so all right chuck we got to call it quits there all righty good to have you jeff always a pleasure all right star talk cosmic explainers neil degrasse tyson keep looking out you

Channel: StarTalk

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Keywords: startalk, star talk, startalk radio, neil degrasse tyson, neil tyson, science, space, astrophysics, astronomy, podcast, space podcast, science podcast, astronomy podcast, niel degrasse tyson, physics, Neil deGrasse Tyson, Chuck Nice, color, blue dress, gold dress, scientific advancements, physiological senses, white light, red apple, dark adaptation, the dress, the dress optical illusion, optical illusion, colorblind

Id: OtcxYsUS_wc

Length: 16min 12sec (972 seconds)

Published: Tue Sep 22 2020