It is because sun sends more blue light than violet light (check out a solar radiation spectrum graph, wich is peak in the blue wavelength and drops for violet wavelength). Also, detecting light cones in our eyes are more sensitive for blue wavelength and drops for violet and red wavelengths (check out also a sensitivity graph for these cones).
from what I've read, the thing is, the amount of stimulation on the red cone due to the violet wavelength particles, equals (at least approximates) to the stimulation on the green cones due to the blue wavelength particles. So having a small green cone stimulation + small red cone stimulation + high blue cone stimulation = small white (all cones) + the rest of the blue = light blue (or sky blue). The important thing is to recognize that the 3 types of cones can be stimulated by any visible wavelength, it's just that they have a peak on sensitivity on 3 specific lengths. And violet is not the color of a 408nm wavelength, violet is the color created in our brain after mixing the stimulus of this 408nm photons over all of the 3 types of cones in our eyes.
great explanation, but I wish you talked more about sunrise and sunset. So do reds and oranges appear in the sky because the suns lower and light is being effected by more atmospheric scattering? i'm guessing the red light is able to evade all of the molecules in its path and reach our eyeball while the blue light hits every molecule and scatters out of our site?
I'm confused...since when is GREEN a 'primary color'? Aren't the primary colors red, yellow and blue?? GREEN is a combination of yellow and blue....not primary.
And how would everything be if the sky wasn't blue but transparent? Would we be living like in a dome, seeing blackness far away while looking above us? Would it get darker cause instead of blue sky we'd have black space?
Absolutely perfect!! This video explains physically correct "Why is the sky blue?" Almost all the other hundreds of videos on UA-cam on this subject are just plain rubbish. Congratulations!
Great explanation, This was not understood until 1881, when Lord Rayleigh showed that particles scatter short wavelengths more than longer wavelengths.
Why do smaller wavelengths of light scatter more, I mean I understand the equation, but why? Because it has more chances of interacting? But that wouldn't make sense as there are so many molecules out there! This also seems weirdly opposite to what the Tyndall effect does, why don't particles of true solution show that effect, if anything, they too are "significantly smaller than the wavelengths of light"! Is scattering really necessarily to actually see something?
I have one question, i hope the author will see this: Doesn't the scattered light lose any energy after each scatter? i thought that every scattering shifted the frequency down a lil' bit, thus bringing the color from bluer to redder. Am i getting this wrong? Thanks
This is not logical. If light is entering our atmosphere from the outside and that causes the blue light to scatter so much more than any other color, then physics would say that our WHOLE WORLD would be blue, NOT JUST THE SKY. Also the cloud you think should turn red should also be blue according to your scattering theory because the clouds are below the blue sky, we can obviously see that when we look up, and your scattering effect says that most of the rays are blue so the cloud, which is water, that's receiving mostly blue light would always have to be blue, there's no physical alternative.
The scattered light isn't as intense as the light bouncing directly off of objects, so only the sky is blue and we see objects as their normal color. Maybe an object is a tiiiiny bit "more blue" outside than inside because of scattered light, but again I'm pretty sure the intensity difference means our bodies don't really detect the scattered blue light when there's other more intense light being seen as well. Also, clouds don't receive mostly blue scattered light, they receive mostly the "white" light directly from the sun.
Not really... Rayleigh scattering it's a model that might explain a lot of optical phenomena, but for larger wavelenght, will be larger particles (including molecules and other kinds of particles), for those ones, another kind of scattering explains that, the lorentz-mie scattering.
this is the best explanation I've found so far, and there are many many videos on UA-cam about this topic... nice demonstration and good pacing. Thanks so much!
This is amazing. I think the only thing that has me confused is the two different uses of intensity? We have intensity as in the chances of a photon entering your eye (proportional to 1/λ^4) and then we also have the intensity that decreases as photons are scattered. With the first, red light has a low intensity (well really is proportional to a lower number than say blue light) and so scatters less With the second, red light scatters less and so the intensity is higher or remains higher. Can anyone help with this?
Why does the light from other stars not scatter in our atmosphere as the sun does? I mean there is nothing else that scatters these lights in space before it reaches us right?
Stan Lee They do scatter actually but the light from the stars has significantly lower intensity since it comes from very very very very far away so the only way to notice that light with your eyes is to look at it directly at night. Otherwise, it just not noticeable enough. In case we had extremely powerful sensors in our bodies we could see the scattering of every star that we can see on the sky.
Hi, this helps a lot but I'm still a little confused. Does it mean that there are receptors in our eyes to see violet as well just that it is not as prominent as the other colours? Because in part 2 you talked about the receptors giving us colour but it was a consequence of the two colours only. So if we see violet, it could mean the 3 main colours (RGB) combine together such that violet is formed or just pure violet comes out? Thanks for the help :)
Wow this is so cool! So this is also why clouds look extremely pretty in highly polluted cities at night, yeah? All of the particles in the pollution will scatter basically every blue and green light ray (obviously not all of them, but you get the picture) and the clouds will appear almost pure red?
Nope, all clouds would have these reddish tones if that were true, and the edge of the sun light going down , giving that shadow on the ground of the sun going down, is very even, too even for random light defraction! Being able to see things in shade makes more since that there is a dome or some sort of surface that is actually reflecting light , and giving you an even shading of sunset
Great video, thank you! Why is the sky much lighter near the horizon during the day? If you are looking at the horizon during the day then are you not looking through more of the atmosphere (like at sunset) so why is it pale blue/whitish?
Hi I have a question regarding the white light. Isn't all 7 colours (red to violet) part of white light and not just the red, blue and green? So if violet light waves enter my eyes what will i see? Because now it's not a combination of the 3 essential colours but instead it's the pure violet colour. Thanks for the help!
I think the light is being "scattered" due to electromagnetic oscillation of a molecule -- a more energetic photon will cause more oscillation to molecules that it travels near and therefore more "scattering".
If our eyes were mechanical instead of biological then we would see the sky in violet. Our eyes find it difficult to pick out violet if there are other colours involved, as there is still blue light available we see it.
i have a doubt around your conversations...which colour actually scatters in the sky? blue or voilet? as voilet have wavelength smaller than that of blue and hence has intensity higher comparitively...???
this is kiiiiiinda misleading cuz the colored photons your virtual man is seeing are actually showing up in the retina... grass for example absorbs all colors except for the wavelength known as green.. so grass isn't actually green, it is kicking off the green cuz it can't absorb it.. so it's actually all other colors except green. Trippy right? The electrical wavelengths strike the retinal sensors which correlate to specific wavelengths, which we have labeled as RGB. Also to make things more interesting, your photoreceptor cones and rods are actually facing in towards your skull and not facing out of the eyes.. It's like taking a solar panel (receptor) and burying it in the ground, while it's wire comes out and goes into your house. Somehow the wire is picking up the light (photons), sending the electricity down into the receptor in the ground and then re routing that new information back up the wire that goes into your house to be seen or registered. Nucking futz. Our retina is like a tv screen, and requires green because of the white light that can penetrate green's layer as to modify a plethora of different shades and etc.. When you paint, you substitute green for yellow, because yellow has the white light inside of it.. metaphorically speaking.. yellow is lighter then green and when you mix the paint on paper, there is no white light being projected from the paper in order to mix and match the entire visual spectrum. Also, look into CMYK and RGB differences.. if you work with adobe programs you'll know what I'm taking about. Also if your into cult shit, there are the prime ruling colors.. they rule because they create the other colors. Stimulating both R and B for example would produce the phenomenon known as purple. So half of your colors like.. don't even really exist. Colors are really really fucking weird.
To add on to what Flor said, it's not that the Sun only puts out that light, it's that our eyes can only detect those three colors and their combinations.
Why doesn't the man see three different colors from three different lights? If i have 3 different colored flash lights on my desk, i can see the photons from each flashlight individually. So why do they blend to make one color in the video?
1:22 ok this bothers me, but it is not important. The actual distance between the sun and the earth is 149 600 000 000 metre. the length of your diagram of sun and earth is less than 1 metre, obviously. as u can see, its definitely more than a 100x smaller than the actual thing. :P it does not make this video bad, but it bothers me. nice vid tho ;)
Great video!! Does Raman scattering also takes place in this phenomenon? When does Raman scattering occur? Could you do a smilar awesome video for the colour of oceans?
so then why does the sun appear red during sunset or sunrise as the molecules off atmosphere are still present and which will certainly cause blue to scatter much so the sun should also appear blue and not red.Nice explanation though.
+Rajiv Saxena relatively simple answer. Alle the blue and green is already scattered into other directions away from your eye. So it is mainly the red light arriving at your eye and the sun seems to be red.
Well, not only you did answer, but you did it almost literally at the speed of light XD Thank you for the clear explanation, now i have a bunch of new words to look for. Keep up the good work Marco
Trolling youtube for an explanation on why the sky is blue, best explanation so far. Well done Sir.
Thanks :) very simple and informative....
Fantastic video. The best explanation that I've ever seen.!
Kalyan Chakravarthy Chinnamanthur Venkata nice name
im gay
Oh my Darwin that was beautiful! Thank you so very much for your hard work in sharing your knowledge and doing such a wonderful job.
please do more videos about why is the sky blue so that i can get the main point in defending my case study.
Perfect explanation
Great explanation...
God bless you for uploading such a valuable video.
y is that light becms all nutty when it encountres anythng smaller than its wavelength?gorgeous explanation!keep up the gud work..
best explained!
Awesome ! big thanks
awesome vid
How did u make the simulation??? with which software??
ok we know the equation for rayleight scattering has power to the 4th on the bottom but how come the sky is blue and not violet?
Because of the size of the scatterer particle...
Because our eyes are more sensitive to blue than violet
It is because sun sends more blue light than violet light (check out a solar radiation spectrum graph, wich is peak in the blue wavelength and drops for violet wavelength). Also, detecting light cones in our eyes are more sensitive for blue wavelength and drops for violet and red wavelengths (check out also a sensitivity graph for these cones).
from what I've read, the thing is, the amount of stimulation on the red cone due to the violet wavelength particles, equals (at least approximates) to the stimulation on the green cones due to the blue wavelength particles.
So having a small green cone stimulation + small red cone stimulation + high blue cone stimulation = small white (all cones) + the rest of the blue = light blue (or sky blue).
The important thing is to recognize that the 3 types of cones can be stimulated by any visible wavelength, it's just that they have a peak on sensitivity on 3 specific lengths.
And violet is not the color of a 408nm wavelength, violet is the color created in our brain after mixing the stimulus of this 408nm photons over all of the 3 types of cones in our eyes.
I still don’t get it. I need to understand what happens during sunset and sunrise.
this guy reminds me of Toby Flenderson from The Office
this was so good! thank you so much for doing this!!!!
wow. this vid should win an award. spot on explanation. complete and thorough, as advertised. thanks
Thank you for this explanation! But now it is just after sunset and the sky appears dark blue. Why is blue visible again?
I'm not sure that I completely understand, but uhhh, thank you all the same.
great explanation, but I wish you talked more about sunrise and sunset. So do reds and oranges appear in the sky because the suns lower and light is being effected by more atmospheric scattering? i'm guessing the red light is able to evade all of the molecules in its path and reach our eyeball while the blue light hits every molecule and scatters out of our site?
I'm confused...since when is GREEN a 'primary color'? Aren't the primary colors red, yellow and blue?? GREEN is a combination of yellow and blue....not primary.
And how would everything be if the sky wasn't blue but transparent? Would we be living like in a dome, seeing blackness far away while looking above us? Would it get darker cause instead of blue sky we'd have black space?
Absolutely perfect!! This video explains physically correct "Why is the sky blue?" Almost all the other hundreds of videos on UA-cam on this subject are just plain rubbish. Congratulations!
Great explanation, This was not understood until 1881, when Lord Rayleigh showed that particles scatter short wavelengths more than longer wavelengths.
2019 and I’m just watching this. Phenomenal breakdown for someone who has trouble understanding the slightest things. I fully understand.
I have you beat brother i have such a tough time understanding basic things i voted for Biden
perfectly explained!
complete explaination! unlike other videos that only explains part of the problem.
pretty much the best explanation of this topic after watching +20 vids
Why do smaller wavelengths of light scatter more, I mean I understand the equation, but why? Because it has more chances of interacting? But that wouldn't make sense as there are so many molecules out there!
This also seems weirdly opposite to what the Tyndall effect does, why don't particles of true solution show that effect, if anything, they too are "significantly smaller than the wavelengths of light"!
Is scattering really necessarily to actually see something?
so it means that travelled distance has some important role in the equation....is there any equation taking distance into account?
I have one question, i hope the author will see this:
Doesn't the scattered light lose any energy after each scatter? i thought that every scattering shifted the frequency down a lil' bit, thus bringing the color from bluer to redder. Am i getting this wrong?
Thanks
Trolls gonna troll
nice way of explanation .....loved it ....
This solves tons of problem I'm encountering, millions of thanks.
This is not logical. If light is entering our atmosphere from the outside and that causes the blue light to scatter so much more than any other color, then physics would say that our WHOLE WORLD would be blue, NOT JUST THE SKY. Also the cloud you think should turn red should also be blue according to your scattering theory because the clouds are below the blue sky, we can obviously see that when we look up, and your scattering effect says that most of the rays are blue so the cloud, which is water, that's receiving mostly blue light would always have to be blue, there's no physical alternative.
The scattered light isn't as intense as the light bouncing directly off of objects, so only the sky is blue and we see objects as their normal color. Maybe an object is a tiiiiny bit "more blue" outside than inside because of scattered light, but again I'm pretty sure the intensity difference means our bodies don't really detect the scattered blue light when there's other more intense light being seen as well. Also, clouds don't receive mostly blue scattered light, they receive mostly the "white" light directly from the sun.
@@GiantEnemyGoomba Right, and that's only possible if the sun is below the sky.
wow, great, super, excellent, splendid, awesome tutorial............
here's a stupid question, why the larger wavelength of the light, the harder it will scatter?
Not really... Rayleigh scattering it's a model that might explain a lot of optical phenomena, but for larger wavelenght, will be larger particles (including molecules and other kinds of particles), for those ones, another kind of scattering explains that, the lorentz-mie scattering.
this is the best explanation I've found so far, and there are many many videos on UA-cam about this topic... nice demonstration and good pacing. Thanks so much!
Best i've ever seen you cleared my doubts
This is amazing. I think the only thing that has me confused is the two different uses of intensity?
We have intensity as in the chances of a photon entering your eye (proportional to 1/λ^4) and then we also have the intensity that decreases as photons are scattered.
With the first, red light has a low intensity (well really is proportional to a lower number than say blue light) and so scatters less
With the second, red light scatters less and so the intensity is higher or remains higher.
Can anyone help with this?
Because blue light has a short wavelength, it is scattered. so where does the remaining light with the longer wavelengths go?
They are less scattered / point more toward the observer, hence red/yellow sunsets.
superb
Why does the light from other stars not scatter in our atmosphere as the sun does? I mean there is nothing else that scatters these lights in space before it reaches us right?
Stan Lee They do scatter actually but the light from the stars has significantly lower intensity since it comes from very very very very far away so the only way to notice that light with your eyes is to look at it directly at night. Otherwise, it just not noticeable enough. In case we had extremely powerful sensors in our bodies we could see the scattering of every star that we can see on the sky.
It does scatter, but we can barely see it. That's probably the reason why the night sky is slightly blue/purple and not completely black :)
thank you. it was really great
Hi, this helps a lot but I'm still a little confused. Does it mean that there are receptors in our eyes to see violet as well just that it is not as prominent as the other colours? Because in part 2 you talked about the receptors giving us colour but it was a consequence of the two colours only. So if we see violet, it could mean the 3 main colours (RGB) combine together such that violet is formed or just pure violet comes out? Thanks for the help :)
Wow this is so cool!
So this is also why clouds look extremely pretty in highly polluted cities at night, yeah? All of the particles in the pollution will scatter basically every blue and green light ray (obviously not all of them, but you get the picture) and the clouds will appear almost pure red?
amazing video now i under stand
Excellent video! It's a huge help! Thanks!
Thank you very very much. ..... Now i have a good concept about light and colour.....شکریہ
this was perfect. thanks a lot.
Thanks for your detailed explanation !!
Great video! You did a great deal less hand waving than other explanations I've seen.
Excellent explanation! Thank you for helping me see the light.
(and thank you to my dog for typing this for me).
the best video I have seen explaining this. Thank you and well done. Absolutely great
ur the best teacher ever!!! Im 11 and i understand fully everything you said thanx
A mere child when you wrote this comment. I wonder how you are doing in life now as a 22-year-old adult. I hope you're doing well.
Nope, all clouds would have these reddish tones if that were true, and the edge of the sun light going down , giving that shadow on the ground of the sun going down, is very even, too even for random light defraction! Being able to see things in shade makes more since that there is a dome or some sort of surface that is actually reflecting light , and giving you an even shading of sunset
Great video, thank you! Why is the sky much lighter near the horizon during the day? If you are looking at the horizon during the day then are you not looking through more of the atmosphere (like at sunset) so why is it pale blue/whitish?
I enjoyied very much your explanation, and i learned a lot ! thanks =) please keep making videos
when you said deflected or scattered you mean that the photon is absorbed by the molecule and remitted ? thanks in advance.
Hi I have a question regarding the white light. Isn't all 7 colours (red to violet) part of white light and not just the red, blue and green? So if violet light waves enter my eyes what will i see? Because now it's not a combination of the 3 essential colours but instead it's the pure violet colour. Thanks for the help!
This is really good! You explained everything is great detail. This video should have 1,000,000 views.
Nice vid n thanks
Thank you for the really nice explanation..
I think the light is being "scattered" due to electromagnetic oscillation of a molecule -- a more energetic photon will cause more oscillation to molecules that it travels near and therefore more "scattering".
If our eyes were mechanical instead of biological then we would see the sky in violet. Our eyes find it difficult to pick out violet if there are other colours involved, as there is still blue light available we see it.
i have a doubt around your conversations...which colour actually scatters in the sky?
blue or voilet?
as voilet have wavelength smaller than that of blue and hence has intensity higher comparitively...???
this is kiiiiiinda misleading cuz the colored photons your virtual man is seeing are actually showing up in the retina... grass for example absorbs all colors except for the wavelength known as green.. so grass isn't actually green, it is kicking off the green cuz it can't absorb it.. so it's actually all other colors except green. Trippy right? The electrical wavelengths strike the retinal sensors which correlate to specific wavelengths, which we have labeled as RGB. Also to make things more interesting, your photoreceptor cones and rods are actually facing in towards your skull and not facing out of the eyes.. It's like taking a solar panel (receptor) and burying it in the ground, while it's wire comes out and goes into your house. Somehow the wire is picking up the light (photons), sending the electricity down into the receptor in the ground and then re routing that new information back up the wire that goes into your house to be seen or registered. Nucking futz. Our retina is like a tv screen, and requires green because of the white light that can penetrate green's layer as to modify a plethora of different shades and etc.. When you paint, you substitute green for yellow, because yellow has the white light inside of it.. metaphorically speaking.. yellow is lighter then green and when you mix the paint on paper, there is no white light being projected from the paper in order to mix and match the entire visual spectrum. Also, look into CMYK and RGB differences.. if you work with adobe programs you'll know what I'm taking about. Also if your into cult shit, there are the prime ruling colors.. they rule because they create the other colors. Stimulating both R and B for example would produce the phenomenon known as purple. So half of your colors like.. don't even really exist. Colors are really really fucking weird.
So by that logic the sky is not blue, it's black, yellow, red, green, purple, white, pink, orange......
So why can't we see the stars in the picture of our planet? Does that have to do with reflection of light?
Very helpful, thank you! Does the sun only give out red, green and blue light then?
No. It gives out all sorts of light. All the colors, plus the rest of the electromagnetic wavelengths (ex: xrays, gamma rays, microwaves, etc).
To add on to what Flor said, it's not that the Sun only puts out that light, it's that our eyes can only detect those three colors and their combinations.
Those are the primary colours yes
great....i loved it
this is the best explanation so far. thank you. I like the slowness.
Why doesn't the man see three different colors from three different lights? If i have 3 different colored flash lights on my desk, i can see the photons from each flashlight individually. So why do they blend to make one color in the video?
God fucking dam, this guy deserves to get paid a lot!
That was really well explained !!!
Roughly better than many of those other videos that are trying to “ explain “ it ..
Thanks man for your efforts
I got told when I was young if the sky is red before the day ends it's gonna be hot the next day
You need to include Mei scattering otherwise your model is incomplete.
awesome sir
Great explanation - my 9yr old son gets this now :-)
Why isn't UA-cam promoting this video though?
1:22 ok this bothers me, but it is not important.
The actual distance between the sun and the earth is 149 600 000 000 metre. the length of your diagram of sun and earth is less than 1 metre, obviously. as u can see, its definitely more than a 100x smaller than the actual thing. :P
it does not make this video bad, but it bothers me.
nice vid tho ;)
That diagram looks way bigger than 1 metre, it is many dozens of earth radiuses apart.
cool..thanks for the answer.i was thinking of interference, diffraction n qm effects.
does this have anything to do with blue eyes in people and a few animals, ie, siamese cats ? thanks
Excellent video, thoroughly explained.
oh so when we see violet, only the blue receptor is being used? Thanks again for the help :)
Perfect! Simply perfect! Keep up the good work. Subscribed!
great video.. but I had a doubt .. Is rayleigh scattering the same as tyndall effect?
Amazing thank you! I really liked the animation with the photon canons :p
Great video!!
Does Raman scattering also takes place in this phenomenon?
When does Raman scattering occur? Could you do a smilar awesome video for the colour of oceans?
so then why does the sun appear red during sunset or sunrise as the molecules off atmosphere are still present and which will certainly cause blue to scatter much so the sun should also appear blue and not red.Nice explanation though.
+Rajiv Saxena relatively simple answer. Alle the blue and green is already scattered into other directions away from your eye. So it is mainly the red light arriving at your eye and the sun seems to be red.
Thanks a lot. Very good explanation.
Very well done, thank you very much!
Very nice vidio to uderstand please give me your other vidio web address
Well, not only you did answer, but you did it almost literally at the speed of light XD
Thank you for the clear explanation, now i have a bunch of new words to look for.
Keep up the good work
Marco
Put some adds on your vids, make some money - you sure do deserve it.
lol we have to watch this for our science homework. Pretty good!
viva well done
thanksss!! very good explanation...i hope im better at physics
Thank you!
Best explanation ever!! Thanks!