Why Do We See Colors?

We only see radiation with 400nm to ~700nm. It seems so strange when the electromagnetic radiation spans factors and factors of 10. Why such a small slice? Why just Red, Green, and Blue? and more importantly... how?
Note: At 6:30 I say tetrachromats don't see 'more' colors than trichromats. That was a mistake, I meant to say 'New' colors. They certainly see more. Just not new ones. Unless you consider hues and shades new colors.
Sources:
www.ncbi.nlm.nih.gov/books/NB...
www.ncbi.nlm.nih.gov/books/NB...
hyperphysics.phy-astr.gsu.edu/...
iovs.arvojournals.org/article...
Color Vision: Perspectives from Different Disciplines

[@urbanladiebug7249]

Why is this so underrated?This channel has a great deal of research and visual effects! 10/10

[@yello171]

Came here to say this

[@he-harshedits361]

kzbin.info/www/bejne/qWSzhmiYoZdppK8

[@davidmurphy563]

The effort that went into the research, scripting, 2d and 3d visuals in this is truly impressive. Thank you, the result was outstanding. Funnily enough I'm decently colourblind and you'll be surprised how little that matters in everyday life. Of course, seeing sabretooth tigers in reeds isn't a huge part of the modern gene selection process. :) I'm really surprised that these chemical interactions can happen so quickly. Particularly when it comes to free-floating enzymes. Do you know: does this happen 24 times a second or it is longer and different cones are cycling in a phased way?

[@ButWhySci]

Thanks for the kind words. Funnily enough I wonder''d this very thing but I didn't feel I understood the process' enough to include them. Here's a long paper on this exact thing: www.ncbi.nlm.nih.gov/pmc/articles/PMC3398183/ Cones have a faster refresh rate than Rods and If my understanding is correct then pigment proteins in chicken cones take about 7 WHOLE seconds to rest back to their normal version. Now I'm pretty certain that doesn't mean the cell takes that long to reset. But the individual opsin does. Whereas Rod pigments in chickens take ~210 seconds to reset. Which is even crazy longer. You experience this yourself when you walk into a dark room. Your Rods are still activated from the previous light and it takes time to "cool off" to observe the new light level. So my understanding is that an individual rod/cone doesn't have a particularly high refresh rate (the activation rate is VERY fast though ~20ms in chickens) and due to the large number of rods and cones, as our vision moves around it gives them opportunities to reset and our brain does the rest. Again, I can't confirm thats accurate. I haven't researched that particular aspect of vision.

[@davidmurphy563]

@@ButWhySci Before I look at the paper you linked (and thanks for both that and your thoughtful analysis) let's apply some critical thinking to this. I find it helpful to think through a problem before trying to interpret the science. We know that a frame per 7 secs delay isn't what we experience. We can reasonably infer that there are random elements in the timing of this process, how close enzymes are to the receptors in particular. We also know that each cone has many receptors and there are many cones. What we (I) don't know is whether the triggering of one receptor has a cascade effect on others. From what you explained, it would seem not. Just that a moment of high intensity light at will trigger more receptors. Therefore, different receptors must have different trigger state thresholds. Otherwise they would all either be triggered or not triggered. I think that follows. So, unless we are at a light level below the tolerance of all cones (your night time condition when only rods fire) then this is effectively an analogue and not a binary system for cones as a whole. That's to say, there's a general level of triggering in any individual cone which increases with more light. However, we know this isn't totally true either, look at a bike wheel spinning at just the right rpm and it will appear to hold still. So, it seems reasonable to infer that the receptors aren't on a clock cycle but the neurons are. There isn't more latency at night than during the day (I think that's true) so this would suggest the neuron timing is independent of enzyme activity. Which means that the real problem is not refresh but latency. When you flash a light, it's okay for the cycle to take 7 secs as long as most of that time is the reset and not the transmission phase. That's to say, the receptors have to be "spring loaded" as it were in a high energy state. That would seem to match our experience of suddenly turning off the lights and the image fading over time. Conversely, turn on the lights from pitch black and they will take almost the entire cycle time to get bright. That would seem to follow but it's little more than layman's conjecture. Let me read the link now.

[@ButWhySci]

@@davidmurphy563 Anecdotally what you say seems mostly right. However, I'd imagine our perception of movement and "frame rate" must also be heavily influenced by the regions of the brain that process it. I know nothing about the visual cortex and just a quick search of it shows it apparently has SIX regions! Thats the crazy thing about science. The rabbit hole never ends.

[@davidmurphy563]

@@ButWhySci Haha, yeah it's a rabbithole for sure! I never understand people that cling onto pseudoscientific beliefs, aside from being plain wrong they're invariably dull oversimplistic deadends. Real science is way more interesting. You made a good point about the cortex, still, I think I need to limit my investigations to the eye, there's such a thing as biting off more than you can chew! :) It seemed to follow yes but I'm not expecting what I said to be right, finding out how you're initial thinking is wrong is the best way to learn in my experience. I'm half way through the paper with a few notes and I'll do a bit more reading this evening over a cold beer or two. I likely lack the grounding in biology to unravel it properly but if I do learn something I'll let you know if you're interested. Fascinating subject this.

[@ButWhySci]

@@davidmurphy563 Yea. One of my main issues with science is papers are presented as intellectually as possible. So unless you are an expert in that field it's kinda hard to follow. Which is important because experts should be the one critiquing your work. But It can definitely turn people off of science. Hence why, even though I'm pretty sure I understand what that paper is saying (like it never states what VP* is, so although I can say with quite certainty from the context it represents an activated pigment or Meta-II it doesn't state outright). Little missing bits of info makes it kinda tough to feel confident in your interpretation.

[@kennypark]

Loved the balance of detail and clarity for laypeople such as myself. Excellent video, instant sub.

[@darkseraph2009]

A neat fact: I actually can see near visible ranges of UV light. In fact, the S cone of your eye can detect a range of approximately 20 nanometers into the UV part of the spectrum. The reason you don't normally detect it though is because the lens that focuses light into your eye also filters out UV light. My filters are either damaged or did not form properly. As a result, daylight has a bright but subtly pale-violet component to it. The only reason I discovered why I find sunny days to be unberable is because of a pair of transitions glasses I used to own. Turns out photochromic lenses block UV.

[@NethanielShade]

I wonder if I have a similar issue. I've always been super-duper sensitive to sunlight, to the point where I wear sunglasses every time I go outside, even on overcast days. It's just routine for me, muscle memory to grab my sunglasses, and I don't think about it very often. But people who don't know me well often ask why I'm wearing sunglasses at sunset or on overcast days lol.

[@pootzeketzi1233]

@Zem So you are able to differentiate sunlight and just like white light?

[@secondarycontainment4727]

People that have had it removed can see ~UV. Can you detect radiative ultra violet? Can you see the "light" from a remote control?

[@sipntea]

Wow! I’ve never heard about someone seeing daylight as slightly violet! I could only imagine what that would be like!

[@sipntea]

I wonder if you can see the difference between someone who is and isn’t wearing sunscreen! Because sunscreen does block the majority of UV light

[@zeenix4647]

Please keep making more videos I've never enjoyed a science vid with such high detail and amazing animation. Thank you so much :)

[@Watchoutwinston]

I feel the exact same way! Please continue to make content!

[@Mawa991]

Vision Researcher here: good video. For those interested, there is a bit more to say about why we dont see UV and infrared. UV: our eyes are to big. As a general rule, animals with big eyes dont see UV. That’s because UV light gets scattered inside the eye ball before reaching the retina. Some birds can see UV, some cant - you guessed it: small birds can, big birds cant. Infrared: here the problem is heat. Heat radiates in Infrared. So if we would see infrared, everything would glow and that signal would be all over the place. It wouldn’t help us.

[@flyinlow1]

What an enlightening notion. "If we needed to see it, we probably would".

[@MijinLaw]

They could have elaborated in one aspect though. Most mammals only have two kinds of color cone in their eye; this is because our collective ancestor was nocturnal, and it is difficult for eyes to be both sensitive to low light and color at the same time; mammals' color vision essentially regressed. Primates evolved red back again; an advantage of this is that we can tell when fruit is ripe. But it would be weird to say that 3 primary colors is the goldilocks "just right" number, when only a minority of species on earth have that number.

[@JaiJaiSings]

the effort behind this video. Someday this channel's gonna have hundreds of thousands of subs :) keep it up mate

[@SoulDelSol]

I'm red green colorblind and your comparison of tetrachromates to regular color vision is a good way to help regular color vision people understand what it's like to be colorblind. I often say that i can't distinguish between colors that other people can, or certain colors look same to me but different to you. This very well explains it. People say "what do you only see a few colors?". I respond that no i still see huge array of colors but i just can't tell close shades apart, particularly colors that have greens and/or reds in them. I bought encroma glasses which has filter that blocks out wavelengths of light where red and green cones overlap, allowing them to each be stimulated separately.

[@nicholasauwaerts2280]

Next science clic / Smarter every Day / Veratasium channel. You're one of the best channels who can explain something that satisfies both students as teachers! I'm using you're video's in my classroom and i see the diffirence before and after it in the students.

[@steventhehistorian]

You should tell your school district about the success you're seeing so they can (and should) publicly recognize the public good this channel provides. That might help the channel get more traction and resources to make more content.

[@siraryx]

Love the detailed simplicity in explaining advanced topics. The views and subscribe count ought to be way higher considering the empirical quality. PS: Since you're making these great videos about light, could you make a video that answers wether light can be bent (i.e. by gravity), can photons bounce off one another, how can information stored in light be teleported in quantum mechanics, or how can quantum mechanics disclose if information transferred through fiber optics has been altered or eavesdropped on?

[@datbarricade9995]

I had the basic function of the eye in 11th class biology. But damn this is interesting and a LOT more complicated than I thought. We stopped at "There is Retinal, which gets excited and changes its form." and I already thought this is super high detail. Really nice, gonna watch more of your stuff :D

[@tnt1127]

This is an absolutely amazing video!!!You explained the photo transduction cascade process well that it can be understood in regards to cones!! I really fell on a gem because it was really hard to find videos that explain the photo transduction cascade but with cones instead of rods! I also really love the level of detail in this video and how much research was put in! The animation is also so good!!! Please keep up the amazing work! :D

[@eltiobry3859]

Right now you have 200k subs, that is criminally low, the detail in your videos is so good that i am definitely going to watch all your videos, thank you so much for these, they are invaluable. Also feels like my brain is eating candy or something

[@cassiogroh7844]

I love your videos! I can't stop thinking about the effort you make to produce all this content, awesome job! Ps: please turn down the background music a little bit, sometimes it's hard to focus because it's too loud

[@danktankdragkings7117]

You earned a subscription with one video very well done. And I've never seen the protein chain explained when asking why color. Thank you.

[@josewelingtondasilva1958]

You are insanely smart. Quite impressive teaching there. About the video, it has also very good pictures and direction

[@MeesterG]

I just found you, this is the 2nd video I see. But I'm hooked! Going to watch everything now. I love the depth you're willing to go to and the animations are so amazingly good I can follow those more difficult concepts (I'm a primary school teacher). What do you use to make the animations?

[@EliasMheart]

Very good video! Seriously, I am still baffled by your explanation of gravity, which I discovered... what, 4 months ago? Love your vids! Good fortune to you :)

[@SeaTolli22]

Most underrated channel I've seen omg you deserve so many more subs

[@theladd4370]

I saw you writing about not wanting ads on your videos and I can understand that, but if you set up a Patreon or something similar I would definitely subscribe cuz your content is so well made and you deserve support if you want it.

[@TroyeKizzz]

Very nice explanation and good animation! Thanks for the video!

[@mrmotl1]

Beautiful animations and great work.

[@batty128]

Fantastic explanation 👍👍👌👌. Keep making such great quality content please . Thanks for this video.🙏

[@TheLeekWeek]

Very cool video! Thanks for the explanations!

[@varunds6328]

Nice effort and hardwork is done in the research and video

[@AmitKumar-xw5gp]

Awesome animation and very well explained..

[@paddyconnolly331]

Keep making videos man I love em !!

[@eliedidomenica542]

BEAUTIFUL !!!!! 😍😍😍 Now, I can see what is going on inside my eyes when I am watching KZbin videos. Thanks !

[@GraveUypo]

seeing ultraviolet would probably be a hindrance to us. The atmosphere scatters that a LOT more than even blue light, so there's a constant heavy "fog" in the ultraviolet spectrum that would limit the range of our sight. by not being able to see ultraviolet, we can see right through it. it's like an x-ray vision cheat code. well, kinda. since we would still see other colors, the uv "fog" would feel like a color filter being applied to distance objects. it would be kinda annoying but could maybe actually help with long range depth perception.

[@mastershooter64]

What if we could see both UV and infrared? then it'd be perfectly balanced....as all things should be.

[@ionutgabriel3102]

Nice video. Thank you. I have a question for you - WHY plants have different hues of green, and even different colors? What might be the advantage?

[@willy4129]

This channel is really incredible.

[@robson6285]

Tjee what a beautifull videolessons! And especially, how great that they are só exact and clear and thus, so understandable. I cannot think about how much work it must be to make it so nice, but the most i admire the fantastic insights, technical and chemical and and and, tjee this man sounds so young to have gathered so much knowledge, wíth the insights needed to make videolessons so clear ánd complete, and enjoyable to watch, and even addicting(especially for all us nerds who are lucky enough to discover this channel), and, and and... Oh, i type to much. But in short, even in one word? Maybe Tjee!? Or realtotallearnjoy?! Or better simply: Wow!!!

[@7milesdavis]

Your channel is awesome!

[@patfts2518]

I learned this in med school, very nice animations, keep it up :)

[@Belial-jv5tq]

Even though you don't mention it in this video, you made me understand and visualize better how my Protanomaly color blindness works. Thank you.

[@HenriFaust]

FYI: OPN1MW2 detects light in the ultraviolet range. Tetrachromats are sensitive to light outside of the range of normal color vision, though a lot of ultraviolet light gets absorbed by the lens of the eye.

[@xd2k944]

Extremely underrated channel

[@Safe_intentions]

Note: At 6:30 I say tetrachromats don't see 'more' colors than trichromats. That was a mistake, I meant to say 'New' colors. They certainly see more. Just not new ones. Unless you consider hues and shades new colors.

[@Paraselene_Tao]

Your channel has extremely high quality content. It's like vsauce, kurzgesagt, professor Dave or some other high quality science channel. Thanks.

[@judetaylor5]

This Channel is incredible

[@steventhehistorian]

This is incredible thank you thank you for this video! I learned so much!

[@flintbrenick]

Great video!!

[@edualbergaria10]

Very nicelly done!

[@Arominit]

Learned more from this channel this week than in high school 🙃

[@matthewc5640]

Just to nitpick, it's the lens that absorbs near-UV and the cornea that absorbs even higher-energy UV still.

[@methylmike]

That signal path for vision is mad. Is there a side of the spectrum which has a higher electrochemical cost? Gaming makes eyes tired quick, but I could drive, looking through my windshield all day. I wish I could sit and ask you questions for like an hour

[@ericbasilio5062]

that's the kind of videos i need in my life!!!

[@yuta2349]

The visuals were so damn good !

[@sui604]

great vids!

[@sketchmastertask3093]

Great info but background music is a bit distracting. Thanks for the info though 👍 your awesome

[@MijinLaw]

I don't think human tetrachromats are anything like birds or insects that have 4 color channels. Because in humans it's two pigments that almost entirely overlap. It's a bit of a fluke that exists for technical reasons related to how humans evolved trichromacy. "Tetrachromat" women can indeed distinguish more shades of red, and, as you say, might notice that a white surface actually has a slight hue. But true tetrachromacy would be a whole new primary color that together with RGB would make a vastly wider color space.

[@imlassuom]

Well done!!👏🎩

[@robert.adamek]

I know I’m late but wow! Keep it up man

[@pkmpkm03]

Glad that I clicked on the video... learnt something new ❤️

[@kenperlman2204]

Interesting. Thanks.

[@Tay-ky3fi]

Awesome!

[@DeskCanSaw]

Your videos are amazing! Please remember me when you are famous :)

[@simplesimp3780]

So if i choose a color on a digital color weel and see how the value numbers are changing, my body does kind of the same thing to see the colors i look at?

[@barryhall7]

Just wow and thanks :-)

[@broyojo]

being able to see infrared would be helpful though if humans hunted at night, but that was probably always too dangerous so it never really evolved that way

[@OrlandoMGarcia]

If you are on pich dark room and point a tv controler to your eye depending on the diode you could se fromsome red to a very faded light

[@broyojo]

@@OrlandoMGarcia yes I've noticed this before

[@CT-pi2gl]

How do scientists observe all that stuff about protein chains? And, it's boggling to think that the rise and fall, rather than the peak, of the color spectrum of each rod is what is most important to give the brain color info. Never considered that. Excellent job!

[@josephang9927]

They can't. They study one step at a time in thousands of studies and unify them all to reconstruct the process. Usually from animal studies.

[@polarwind77777]

You deserve way more exposure than you're getting. I'll try to fix that.

[@noahway13]

Do other stars put our the majority of their light in different wavelengths ? So that a being there would have different vision than ours?

[@stankfaust814]

We evolved to see these specific colors as it aided in food selection and survival of those who had the capability and therefore passed on their genes. The mantis shrimp sees a far broader spectrum than we do, but there's no need for us to see further than we do while the shrimp needed it for their survival. IT's something they use to compete and survive and so the feature is passed on genetically

[@jgmeng88]

Next level learning

[@BB-zi5wi]

My hat is off for the creators of this channel ❤

[@gregoryzy]

Perhaps the question would be: why does we see color as is, like, low frequency as redish and high frequency as blueish.

[@geo3106]

I think that the problem with seeing a wider range of colours simply using more types of cones (which led to us seeing this specific spectrum) might be space priority. Our retinas must strike a balance between total number of cones versus types of cones, based on the best suited to the respective environment. As far as we are now in terms of evolution, most of us have three types of cones and rods distributed at a ratio of approximately 1:20, among other specifications, some smaller ones that vary depending on the individual person or even eye. Given the benefits of a greater variety of cones, a smaller variety allows for a greater quantity of each type, making the organism more sensitive to light intensity, also increasing the intensity range and therefore the possibilities of color perception ratios. Granted an additional type of cone within the same spectrum can help to differentiate between a certain range of colors better also.

[@jailafrappecommetaimes2931]

So I know that electron transitions in atoms produce photons and that electron transitions are quantised (i.e. requires an exact amount of energy to cause the promotion). So my question is: how do the light cones in our eyes absorb photons over a range with their peaks even just a smaller range as-well, if the the amount of energy necessary to activate the chromophore (though differing for each cone type) should be one exact value. Should we not just see infinitely sharp spikes at those exact values?

[@LilCalebW]

Nice

[@SepiaDragoonGR]

5:35 - 6:00 “If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” _Nicola Tesla_

[@GoingtoHecq]

vision takes a very long time to develope and evolve. Yes there are women with a fourth color receptor, but it is very VERY rare for them to be hooked up to the brain at all, much less make any difference in their vision. Moreso there is a lot that has to evolve in the brain for it to even be able to process another color. Considering that we are mammals, our eyes are very advanced. There are no mammals outside of primates that can see red, and only a few primates that can. There are definite advantages to being able to see more spectrums of light, it's not that they're useless. We just haven't been able to evolve sensitivity to those wavelengths yet.

[@avondras]

Wish more people saw this video

[@jakkanagoudapatil5894]

Sir. I m seeing cream colour ,orange, yellow and blue live colours.

[@imagreatguy1250]

U r amazing 👍

[@andrewhamp2893]

"The Night I Slid Down Fireman Bob's pole?" Lol

[@stephenbrand5661]

I've always wondered whether those creatures in the Predator movies were supposed to have originated in a red dwarf system since they had infrared vision and I know that the emissions from red dwarves peak in that part of the spectrum.

[@Misses-Hippy]

I look at my yellow coffee cup and KNOW there is blue in there. Is that knowledge or perception? I know how to mix paints to achieve that hue of yellow. Otoh, how do I know this? Do I see it first then know. Does knowledge infringe on perception or aid it?

[@royslapped4463]

but why don't we have a channel called but how? or but when? or but where? or but what?

[@imtrex521]

by extrapolation, denizens of a red dwarf will see whatever kind of light a red dwarf radiates., etc. well explained, thanks.

[@dominicsey3032]

Can someone direct me to a book that has the molecular operations of our senses and physiology?

[@ThatGuy-zw4le]

7:30 i can spot the difference in the first two red squares. Does that makes me a tetrachromat?

[@breezyx976]

I always wondered why we couldnt see infrared, it seems like a gamechanger for night vision and spotting camouflaged animals, like in combat. Snakes can see it so its not impossible

[@ahmetrefikeryilmaz4432]

@7:39 dear viewer, you are not a tetrachromate, at least not probably. You saw a difference between the two colors because of video compression, so chill.

[@jakkanagoudapatil5894]

Sir. I will get more sweting in my spine. Why?

[@LupusRutilus]

So how does the brain pick a colour when it gets the data? Would a colourblind guy with repaired cones still see no colour because the brain doesn't know what to do with that extra information? If one's brain never has learned the concept of colour, how can colour be perceived... And does every brain just guess from birth?

[@luvr381]

So why no yellow color vision?

[@elephantjuice7192]

Background music is what?

[@metroidman3893]

Bruh you need to do an addendum of this video to account for Mantis Shrimp. I NEED TO KNOW WHY THEY HAVE SO MANY CONES BRO.

[@GraveUypo]

idk, probably to increase their ability to see through camouflage?

[@nawtmyrealnamelol]

The real question is why the specific qualia of red/green/blue? There are seemingly infinite numbers of color perceptions that could be consciously experienced. There probably isn't a universal consistency of color experience per any given conscious organism, but maybe there's more overlap with more fundamental experiences like pain or hunger. It's interesting to think about every sufficiently evolved organism in our universe experiencing something similar, and what that implies for the nature of consciousness as a whole

[@IWasAlwaysNeverAnywhere]

woah an unexpected viewpoint nice

[@dek5775]

what if they made glasses or smth that disable the visible light spectrum and allows other type of light to pass throu? i mean obv we wont see anything lol

[@EliBartlit]

These videos fuck! You do an amazing job

[@gobigobi1010]

When I go sleep I see I Green color I can control pls say how to get away thos

[@raresmircea]

2:30 - 4:15 Section dedicated to all those folks who think that they see "light". The physical light from the environment stops dead within the eyes. What goes further is a pattern that’s perpetuating as chemical and electric phenomena. The light that you see is in fact a qualia, a qualitative property of the hallucination that the brain generates and "projects" over the outside environment.

[@amazingdoge4122]

the human body is so amazingly complex

[@mk-np1ez]

music used?

[@ButWhySci]

It's my own composition

[@OrlandoMGarcia]

So there is suns that we cant see?

[@sodiumvapor13]

Great video! Hope this channel take off. Also, another reason we don't see ultraviolet has to do with Rayleigh scattering. If UV were visible to us, it would be very difficult to see farther than short distances due to the high amount of scattered UV by the atmosphere. It would make everything look very hazy, as if there were always smog in the sky, rendering long distance vision impossible.