Why Isn't The Sky Purple?

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  • čas přidán 10. 11. 2014
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    Why isn't the sky violet?
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    Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!
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Komentáře • 1,5K

  • @NimbleSnek
    @NimbleSnek Před 9 lety +1120

    Alright guys, it's official. The sky is gravy.

  • @LaughterOnWater
    @LaughterOnWater Před 9 lety +192

    *Kid:* "Daddy, why is the sky blue?"
    *Daddy:* "Because it's basically gravy, kid."

  • @GoofyPilled
    @GoofyPilled Před 9 lety +865

    Gotta admit, a purple sky would be funky as hell.

    • @linkinl1
      @linkinl1 Před 9 lety +51

      Purple master race

    • @RyuuTsubasa
      @RyuuTsubasa Před 9 lety +15

      Vermacian Purple Haze :3

    • @Lightningblade67
      @Lightningblade67 Před 9 lety +138

      It wouldn't because we would be used to purple sky, so it wouldn't be any special or odd to us

    • @Beagle4Bagel
      @Beagle4Bagel Před 9 lety +64

      Lightningblade You must be fun at parties.

    • @64whatever
      @64whatever Před 9 lety +81

      Hehehe, I bet someone in a parallel universe would be saying how funky it would be if the sky were blue :P.

  • @MaraK_dialmformara
    @MaraK_dialmformara Před 9 lety +796

    A poem:
    Newton's blue is cyan,
    Newton's violet is blue
    For indigo he said "pretend it exists",
    And we all too often do.

  • @alberthollow1737
    @alberthollow1737 Před 9 lety +446

    Came to learn about light, left knowing how to make vegetarian gravy.

    • @oscargordon
      @oscargordon Před 9 lety +6

      That's not really gravy, and you can't make bacon out of tofu.

    • @Mykasan
      @Mykasan Před 9 lety +2

      oscargordon actually....you can.

    • @oscargordon
      @oscargordon Před 9 lety +10

      ***** THAT'S NOT BACON!!!!!!!!!

    • @Mykasan
      @Mykasan Před 9 lety +3

      oscargordon Capitalising your sentence doesn't change the fact that it is bacon, it is called like that. It is just not made from pork.

    • @oscargordon
      @oscargordon Před 9 lety +13

      ***** The civilized world disagrees with you.
      en.wikipedia.org/wiki/Bacon
      The USDA defines bacon as "the cured belly of a swine carcass"
      And you pretending tofu can be sort of made to resemble bacon doesn't make it bacon. If your religion says you can't eat bacon, why on earth would you want to try to make something to imitate bacon? Who do you think you are fooling?

  • @SolidSnake684
    @SolidSnake684 Před 8 lety +244

    I get it!!
    (I don't get it)

  • @ThreeXcore
    @ThreeXcore Před 8 lety +128

    Am I the only one who has to watch these videos 2-3 times to even get a glimpse of what he's saying?

    • @Azrage
      @Azrage Před 8 lety +6

      +Viktor Rebake Usually I can understand these pretty well, even if I don't pay much attention to the video.

    • @aktan4ik
      @aktan4ik Před 7 lety +1

      cuz you are 'murican

    • @ayushahuja1084
      @ayushahuja1084 Před 6 lety +2

      ThreeXcore Man u r perfectly normal. even i did't got it in the first try....

    • @lachlanevans1157
      @lachlanevans1157 Před 6 lety +2

      yeah... probably

    • @YYYinka
      @YYYinka Před 6 lety

      ThreeXcore me too

  • @JohnMichaelStrubhart2022
    @JohnMichaelStrubhart2022 Před 9 lety +84

    When I was little, I used to dream that the sky was that color you see just after a lightning flash. The whole sky was like that all the time.

    • @TheRealBOBlibob
      @TheRealBOBlibob Před 9 lety +1

      What colour is that?

    • @JohnMichaelStrubhart2022
      @JohnMichaelStrubhart2022 Před 9 lety +23

      BOBlibob The closest thing I can think of is neon lavender. Ha ha! Don't really know - it's hard to describe.

    • @CapriUni
      @CapriUni Před 9 lety +3

      John Michael Strubhart In other words: Blue Hot?

    • @JohnMichaelStrubhart2022
      @JohnMichaelStrubhart2022 Před 9 lety +15

      I suppose that's as good a description as any.

    • @CapriUni
      @CapriUni Před 9 lety +5

      John Michael Strubhart Good! 'Cause now, you have a scientific explanation for how you were right all along... ;-)

  • @epacsenur575
    @epacsenur575 Před 9 lety +392

    If we can drink a drink,
    Can we food a food?....

    • @nuste
      @nuste Před 9 lety +87

      We can dance a dance

    • @TheOtherNeutrino
      @TheOtherNeutrino Před 9 lety +47

      Well if we can verb a noun, why not? I like to food something.

    • @AdiDavid10
      @AdiDavid10 Před 9 lety +31

      However we recite at a play and play at a recital.

    • @xINVISIGOTHx
      @xINVISIGOTHx Před 9 lety +7

      we can splinter a splinter

    • @SirNeutral
      @SirNeutral Před 9 lety +6

      Polsevann You can dance if you want to, you can leave your friends behind.

  • @ButzPunk
    @ButzPunk Před 9 lety +16

    Did Henry just imply I have a mac? I'm insulted.

  • @feurenard
    @feurenard Před 8 lety +15

    I finally understand chromaticity diagrams, thank you! I saw them quite often, but I was not able to interpret them.

    • @NFSHeld
      @NFSHeld Před rokem

      Might be many years too late, but you should also check out Captain Disillusion's video "CD / Color". It has a whole series of animations doing visual representation of what's going on with those diagrams.

  • @ellis0896
    @ellis0896 Před 9 lety +59

    So if the atmosphere had no impact on the white light coming from the sun would the sky just be black apart from exactly where the sun is?

    • @oweneastwood2223
      @oweneastwood2223 Před 9 lety +16

      ellis0896 Pretty sure, yeah.

    • @MrClivesinger
      @MrClivesinger Před 9 lety +102

      Yup. If the atmosphere didn't interact with light at all, you'd only see the blackness of space in every direction, except in the direction of the Sun, which would instantly blind you... And thus, you'd get to see even more black!

    • @CFCbluemofia
      @CFCbluemofia Před 9 lety +28

      Yep. It's the reason why the sky is black on the moon. No scattering of light from the atmosphere, means darkness.
      For an approximation, when you are flying on a plane on a long plane flight, look up (or as up as you can) during the day to see how much darker the sky is compared to the brightness when you are on the ground. Less atmosphere in the way, less scattering, the sky would be darker.

    • @skebess
      @skebess Před 9 lety +30

      Canned Snacks They don't "see" nothing. They don't see at all.

    • @oweneastwood2223
      @oweneastwood2223 Před 9 lety +5

      Which is blackness

  • @theespatier4456
    @theespatier4456 Před 6 lety +3

    I believe this video misses the fact that high wavelength light appears purple, because our red cones sense some high wavelength light and that combined with the response of our blue cones produces a purple perception. At 2:00 when he says “pure deep violet” he could have said “purple”. What he calls purple is probably magenta.

  • @erikziak1249
    @erikziak1249 Před 9 lety +20

    I guess if our eyes were more sensitive on the "blue" end, or the curve would be steeper, the sky would be darker, towards violet (or dark blue). Maybe that is what is happening, as there are individual differences between people and they are just used to their "blue". Would not surprise me as I read somwhere that according to one study some people were able to see frequencies up to 1020 nm, which is in the near infrared part of electromagnetic spectrum. Althought I imagine they were "seeing" only monochromatic IR light of that frequency, and it must have been a very intense light, but they saw just some dim, very dark red and hard to recognize outlines. If they were looking at the full visible light spectrum, the IR fequencies would be effectively blocked by the processing of visible light. Might be interesting though to take part in such an experiment. I would certainly volunteer.

    • @isabellev9576
      @isabellev9576 Před 7 lety +1

      Erik Žiak We see blue colors very well, but purple colors are harder to see because the solar spectrum drops off there.

    • @tylerdurden3722
      @tylerdurden3722 Před 4 lety

      People who've had their cornea's surgically removed can see some UV light.

  • @NickSheridanVids
    @NickSheridanVids Před 9 lety +1

    That's the first MP video that's really made me sit up and listen in a while, so thanks and well done.

  • @jampk24
    @jampk24 Před 9 lety +1

    Thank you! This helped me answer a question I've been pondering for quite some time now.

  • @Mimimi0o0o0o0
    @Mimimi0o0o0o0 Před 9 lety +13

    So I look to the sky... and it's cloudy

  • @Boborbot
    @Boborbot Před 9 lety +114

    Why were there 7 videos about optics in the last 10 videos? spread out a bit Henry!

    • @oweneastwood2223
      @oweneastwood2223 Před 9 lety +9

      Nitay A. Because nobody gets it

    • @JamEngulfer
      @JamEngulfer Před 9 lety +109

      Because optics is friggin awesome

    • @Boborbot
      @Boborbot Před 9 lety +20

      JamEngulfer221 of course, but astronomy is more, and i would love to see more of that here.

    • @mr2octavio
      @mr2octavio Před 9 lety +10

      Nitay A.
      Why not some astrophysics

    • @Boborbot
      @Boborbot Před 9 lety +5

      frenchiveruti thats what i meant

  • @TrunksWD
    @TrunksWD Před 9 lety +1

    As always another informative video. These videos are a great way to get a bite sized piece of science.

  • @martindiaz6481
    @martindiaz6481 Před 9 lety +1

    It's been a while since your last video, my friend. I'm glad to see your work in action again. Thanks and goodbye!

  • @tscoffey1
    @tscoffey1 Před 9 lety +8

    Saying that violet is just a dark blue is like saying that red is just a dark orange. They are completely different colors.

    • @RubeeDubee
      @RubeeDubee Před 6 lety +3

      tscoffey1 You're right. I think this fallacy is due to the fact that some people can't see violet. Probably the one who said Violets are blue in the poem is one of them. And probably some people who write science (if they didn't just copy it from someone and missing the skeptical eye).

    • @matthewalexander9277
      @matthewalexander9277 Před 6 lety

      What was considered "violet" back when the colors of the rainbow were listed by Newton, and when that poem was written, is different than what most people refer to as violet today. In the traditional sense Violet is more of what today we would call indigo, while indigo was more what we'd simply refer to as blue today.
      Think about the visible light spectrum - each color seamlessly blends into the next. How can purple as we perceive it, which is a combination of red and blue light, exist on the opposite end of the visible spectrum from red?

    • @RubeeDubee
      @RubeeDubee Před 6 lety

      Matthew, I know that since Newton, there is a mix-up of indigo with another color, still today, depending in which circles you resume (painters, scientists, screen builders, ..) but as far as I've read, the mix-up, or the shift, of indigo, is not with violet, but with the "lighter" blue below that. That blue that looks more like the sky on a sunny day (some kind of cyan), which is what Newton defined blue by, but not with the violet above that. As far as I know, violet (the one just under UV, above blue ánd indigo) has never been confused that way, but with another confusion due to R & B (purple) being similar to violet. That's why people think they are the same. It's also difficult to distinguish them when not seeing them together.
      (And all that besides the fact that some can't see violet.)

    • @tylerdurden3722
      @tylerdurden3722 Před 4 lety

      Your eyes use 3 receptors on your retina to see color (and to mix colors that don't exist...eg. purple or pink)
      It uses the blue receptor to see both blue and violet.
      Purple is a mix of red and blue. There's no such thing as purple...it's blue and red, but our mind perceives purple.
      Violet is a monochromatic color that stimulates your blue receptor weakly because that blue receptor is most sensitive for the wavelength at 445nm (blue).
      True monochromatic violet is perceived by your brain as a darker blue because the same receptor is used and it's less sensitive to that wavelength.

    • @Fixer_Su3ana
      @Fixer_Su3ana Před rokem

      @@tylerdurden3722 Violet light also triggers your red cones in your eyes. So it does look purplish.

  • @leonardtramiel8704
    @leonardtramiel8704 Před 9 lety +79

    This video answers a question different than the one asked. It answers why there aren't purple hot objects and it gives the wrong answer to both questions.
    The reason the sky is blue and not purple is the relative sensitivity of the eye to different wavelengths of light and the details of the solar spectrum (which the video does touch upon). The spectrum of the scattered light is a solar spectrum distorted by the scattering process. This process is very inefficient for red light (long wavelength) and much more efficient for blue light (short wavelength). This produces a spectrum that is predominantly blue and purple. The reason that it isn't mostly purple is the fact that the solar spectrum drops off quickly add to that the fact that the human eye is much less sensitive to purple light than blue and we get the blue sky we see.
    The reason we see a blue sky and not a purple one is the small amount of purple light coupled with the low sensitivity of our eyes to that light.

    • @deloto8004
      @deloto8004 Před 9 lety +11

      Thanks so much for posting. This is the first time I've felt that they didn't answer the initial question.

    • @pisser98
      @pisser98 Před 9 lety +2

      so...why is here a small amount of purple/why does the spectrum drop off quickly?

    • @leonardtramiel8704
      @leonardtramiel8704 Před 9 lety +5

      pisser98 This is a characteristic of all black body radiation.

    • @NoahHasMinecraft
      @NoahHasMinecraft Před 9 lety +2

      He does tell you why if you go to 1:40 he tells why it's blue then goes on to say why it cannot be purple.

    • @leonardtramiel8704
      @leonardtramiel8704 Před 9 lety +8

      NoahHasMinecraft No, actually he doesn't. He gives the reason that really hot objects don't look purple. You can see this by noticing that he is referring to thermal spectra and their relationship to perceived color.

  • @Julika7
    @Julika7 Před 9 lety

    I really like this video! Great job, Henry!

  • @SNBullen0002
    @SNBullen0002 Před 9 lety +1

    AWESOME VIDEO. A lot of work went into this. Good job guys.

  • @spelunkerd
    @spelunkerd Před 9 lety +7

    That Bill Bryson book is outstanding.

    • @MK-ex4pb
      @MK-ex4pb Před 6 lety +2

      spelunkerd everything by him is outstanding

  • @djcbriggs
    @djcbriggs Před 9 lety +4

    Spectral violet consists of single wavelengths that create a combination of red and blue perceptions in the human visual system. However in a digital camera these wavelengths only affect the short wavelength (Blue) sensor and not the long wavelength (Red) one, so they photograph as deep blue. I don't know why anyone would say that spectral violet is actually a deep blue unless they need to look at a real spectrum instead of relying on photos.

    • @user-xr6xi5ym6e
      @user-xr6xi5ym6e Před měsícem

      My photograph of the rainbow in my experiment looks purple

  • @brandonbeck823
    @brandonbeck823 Před 9 lety

    I love this channel. Minute physics and minute earth are arguably my two favorite channels

    • @aurelia8028
      @aurelia8028 Před 2 lety

      how can they be "arguably" _your_ favorite channels? That's something *you* decide.

  • @tsgillespiejr
    @tsgillespiejr Před 9 lety +2

    I wasn't aware that things could be blue-hot. Thank you, MinutePhysics, for continuing to be awesome.

    • @carultch
      @carultch Před 2 lety

      A star like Rigel is a go to example of something that is blue-hot, which is a lot hotter than Betelgeuse that is red hot. Most things on Earth that emit light by virtue of their temperature, are only red hot, because they are at the cold end of the spectrum of temperatures where it is possible to emit visible light, so we associate red with hot, and blue with cold, for this reason. A tungsten bulb is yellow-ish white-hot, and that is about as hot as we can get a solid to be so that it emits as much visible light as possible by black body radiation.
      To get something hotter than this through black body radiation, you'll need it to be in the plasma phase of matter. Gasses usually don't produce blackbody radiation, because they produce their spectral emission lines instead. Lightning is an example of a naturally-existing blue-hot object produced on Earth, and it is in plasma phase of matter.

  • @nwimpney
    @nwimpney Před 4 lety +3

    Monochromatic violet light is definitely purple-ish looking, in spite of the fact that actual purple is a mix of colours. Violet is not just "dark blue".
    It's true that you can't properly show violet light on a typical RGB display, so if showing violet on a display, you would fake it with a very bluish purple, because that's the closest you can simulate how we perceive violet without actually creating violet light.
    Look at a 400nm LED sometime, (often called UV, though it's really just violet). They have no red light in the mix, but definitely look violet (and not blue).

    • @thesisko3715
      @thesisko3715 Před rokem +1

      Agreed. You can see this by looking at a rainbow too, the violet definitely has a purplish hue, it’s not just a deeper blue.

  • @YushiMer
    @YushiMer Před 9 lety +42

    What if : We send a huge mirror 10 light years away , and then see the mirror with a telescope , will we see 10 years in the past?

    • @woobmonkeyp3537
      @woobmonkeyp3537 Před 9 lety +37

      YushiMer Assuming no scattering in the way, and nothing to slow the photons, you'd see yourself 20 years in the past - 10 years to the mirror, 10 back to your eyes. It would likely be a bit longer, however, due to the constant expansion of space itself.

    • @robopie7536
      @robopie7536 Před 9 lety

      *****
      how come?

    • @robopie7536
      @robopie7536 Před 9 lety

      ***** he mentioned using a telescope though

    • @joselotl
      @joselotl Před 9 lety +2

      Of course you won't look directly at the mirror. Yushimer said "with a telescope"

    • @karanrlz
      @karanrlz Před 9 lety +12

      Well you would observe the mirror first a bit over 10 years from now, considering the mirror has its own light which it sends. And considering the light we shine is sent from earth and we shine it exactly perpendicular to the mirror with the angle of incidence to the normal being 0, it would reflect directly back. However, it would take us a bit over 20 years (considering the expansion of the universe) for us to first observe the light sent from earth. You'd also have to take into account the intensity of light as the intensity is inversely proportional to the square of the distance. If it is going to take over 20 years to reach back, you'd have to make sure the light is intense enough to be observed. This also includes the fact that the mirror is going to absorb some of the light. Considering the mirror IS going to reflect everything, you'd also have to figure out whether the light you're observing is the one reflected from the mirror, or just the light from a distant source 20 light years away (to put everything in perspective, this may possibly be the easiest part). Furthermore, as light bends due to gravity, you'd have to make sure there are no massive objects in the way to bend the light off it's path. Or, measure exactly how much the light would bend around a massive object and take that into account to ensure no angle of incidence to the mirror. Also the velocity of the objects as they would be at a different position for when the light is reflected back. Or other sources of light with higher intensity which may blind out our observation of our original light source (for example, the light sent from our sun, in which case it would be too bright to be able to observe earth through the mirror). Furthermore, sending a mirror that far is probably impossible given our time of existence. (The furthest we've sent an object is the voyager 1 which is still inside our solar system). You would have to take into consideration the time to get it to reach there, the fuel, objects which may get in the way, equipment being broken, and the cost of everything else which is involved in sending an object to space. And MUCH MUCH more. And that, my friend, is how science ruins people's imaginations.
      In theory, however, disregarding every other concept of physics and reality, then we would technically be looking 20 years into our past, considering we first shine the light from Earth (10 years there, 10 years back).

  • @oscarricca-mccarthy7008
    @oscarricca-mccarthy7008 Před 9 lety +1

    love the book recommendation, its a brilliant book

  • @realfutbol1
    @realfutbol1 Před 7 lety

    This was a terrific and concise explanation. Thanks!

  • @toolworks
    @toolworks Před 9 lety +3

    I'm colourblind. That graph of all of the colours which a person can see is actually a graph of all of the colours which a colourblind person can see if you are looking at it as a colourblind person.

  • @xINVISIGOTHx
    @xINVISIGOTHx Před 9 lety +3

    love this video

  • @dryued6874
    @dryued6874 Před 9 lety +1

    This is one of the few minutephysics videos that I seriously didn't get on the first try.

  • @pendalink
    @pendalink Před 9 lety

    I know there have been a lot of optics videos but I liked this one a lot!

  • @power-max
    @power-max Před 9 lety +7

    It is too bad we cannot produce computer monitors that can stretch farther out into the color spectrum, and also explains why a picture of a black light never truly captures the deep violet color it can produce (pure 400nm wavelength).
    I wonder if AMOLED displays can actually display a much broader array of colors since the light sources are individual LEDs themselves. Also, what about people with tetrachromatic vision, how do led monitors look to their eyes? If there forth color receptor is, say, yellow, then they will be able to notice a huge difference in color between actual yellow wavelengths of light (like from a prism) and the mixture of red and green most everyone else can see. It would be like the difference between some shade of purplish washed-out yellow and some neon yellow, I'd imagine. (the tetrachromats wouldn't be able to describe the difference to use since they have learned since birth that everything of that basic hue is yellow, so they would not be able to differentiate it by description, even if they did, it would be like tring to describe the difference between red and green to a colorblind person. They do not have any conceptual understanding of those hues.) So in a way we are all colorblind!

    • @power-max
      @power-max Před 9 lety +4

      I wonder if the developer of those quattron LED TVs had tetrachromatic vision and was bothered by the fact that the yellow he saw on the TV was not anything like she sees in the world... That would make a lot of sense! Now if only media such as videos can carry 4 channels of color data instead of 3, the world would be a better place lol.

  • @naominekomimi
    @naominekomimi Před 9 lety +5

    Wait, you said that the sun is white hot until the light reaches the atmosphere, then it turns red hot when it diffuses, and leaves blue hot around. But isn't blue hotter than red? So is the light that is scattered through the atmosphere normally higher on the thermal spectrum than the light scattered through the atmosphere during a sunset (When it looks red)? And if the sun is white hot, does that mean it is lower on the thermal spectrum than the blue light in the atmosphere?
    I'm just a little confused as to where everything falls on the thermal spectrum, and the significance of where they all fall.

    • @lythd
      @lythd Před 6 lety

      the sun is white hot but that white light gets broken up. Thermal spectrum is what it emits, the light can still be split into different frequencies

    • @RubeeDubee
      @RubeeDubee Před 6 lety +1

      Naomi, Your confusion is valid since some information was left out in the video. See my long comment about this.

  • @catiefulcher308
    @catiefulcher308 Před 6 lety

    this video is awesome, thank you!

  • @angelhorsey8905
    @angelhorsey8905 Před 8 lety +1

    I really wasn't sure why the sky isn't just a big smorgasbord of colors but the way you explained it was so simple and understandable. Thanks!!

  • @upsizedown9254
    @upsizedown9254 Před 9 lety +25

    My teacher was obviously wrong and now I feel stupid she said the sky was blue because if the ocean

    • @rKhighlight
      @rKhighlight Před 9 lety +15

      wtf no way. its vice versa. honestly... your teacher is pretty dumb.

    • @RBlazze
      @RBlazze Před 9 lety +20

      My teacher told me we can see the great wall of china from the moon -_-

    • @BallerDan53
      @BallerDan53 Před 9 lety +15

      And they think they don't get paid enough...

    • @isabellev9576
      @isabellev9576 Před 7 lety

      Aleksa Well, you may not be able to see it from the moon without a telescope or something, but I'm pretty sure you can see it from the ISS

    • @NathanK97
      @NathanK97 Před 6 lety

      if they got paid living wage we would have better doctors than those who get paid higher than living wage
      proven fact look it up :D

  • @jade43296
    @jade43296 Před 8 lety +3

    Generally the sky isn't blue, more of a tint. In fact those with the general ideal of the sky being blue see it more blue than those who haven't learned "the sky is blue" as a concept. There is a tribe who's language describes blue and green with a single word, and so when presented a blue object and a green object they find little difference in the color of the two. But ignoring physiology and my pedantic nature the video was fascinating.

  • @A11y_Kat
    @A11y_Kat Před 9 lety

    Love these videos :)

  • @TJskillz169
    @TJskillz169 Před 9 lety +1

    That book... I had to read it for sophomore year in highschool for my biology class... Actually enjoyed it.

  • @EebstertheGreat
    @EebstertheGreat Před 9 lety +3

    With all this focus on color perception, I wonder if you could do a video on the opponent color theory. The way we perceive colors is rather complicated and very much not obvious. For instance, why does violet look more similar to purple than to blue if violet light only stimulates the S-cone (blue cone)?

    • @carultch
      @carultch Před 2 lety +1

      Violet light doesn't only stimulate the blue cone. It also stimulates the red cone, just not nearly as much.

    • @EebstertheGreat
      @EebstertheGreat Před 2 lety +1

      @@carultch As I understand it, violet light stimulates the S cone significantly less than blue light does, but it stimulates the L and M cones only slightly less than blue light, so it seems proportionally more red.

  • @DeconvertedMan
    @DeconvertedMan Před 9 lety +11

    can or do other planets have other color skys?

    • @sciguystfm
      @sciguystfm Před 9 lety +1

      Yes. Look up a Martian sunset

    • @DeconvertedMan
      @DeconvertedMan Před 9 lety +2

      Stefan Marchhart ok! cool.
      Some scifi books have pretty weird colors, what color would be impossible for a sky?

    • @theperpetual8348
      @theperpetual8348 Před 9 lety

      Yep. Not sure why tho

    • @Crick1952
      @Crick1952 Před 9 lety +6

      Deconverted Man as we've seen it all depends on
      a. The size/age of the star
      b. The distance from the star to planet
      c. The size of the atmosphere
      d. The composition of the atmosphere
      e. The size of the receivers eye
      So, any color is possible! Just play with those elements and the color will change.

    • @Ellyerre
      @Ellyerre Před 9 lety +1

      Deconverted Man If you are just taking into account the Rayleigh scattering, you would only get the colours from the thermal spectrum (basically blue or red) for the reasons the video states. But theoretically, if you had an atmosphere with iodine gas it would be purple! And with chlorine gas, it would be greenish-yellow! And there are probably many more colourful gases.

  • @2listening1
    @2listening1 Před 7 lety +2

    I wish I could find an old book that I think was called "A Chemical History of a Candle." It sounds like the book in your ad would remind me of it. It was about all kinds of things that seemed unrelated to me when I read it, but fascinating. Thanks for all your work, :)

  • @NayefAhmad
    @NayefAhmad Před 9 lety

    Finally!! I've wanted a non-technical answer to this question for years!

  • @arthropodliker
    @arthropodliker Před 8 lety +3

    Sooooooooo.... The sky is gravy?

  • @OverlordZephyros
    @OverlordZephyros Před 9 lety +14

    What color would extrasolar terrestial planets with different atmospheres of different composition and different stars, would the color of their atmospheres look like???
    .
    im planning to make short sci fi stories and i want to be as realistic as possible, thanks.

  • @deemon710
    @deemon710 Před 9 lety +1

    Holy cow. Do you really understand all this stuff you teach? You've never lost me so fast as you did with this one.

  • @angelcollina
    @angelcollina Před 9 lety

    I just want to say that your audible ad was enjoyable too. I love Bill Bryson and everything I've read of his so far! Everyone should listen to Bill Bryson, on audible.com of course.
    Gravy sky! :)

  • @AhrkFinTey
    @AhrkFinTey Před 9 lety +5

    1:02 Pink Floyd!

  • @Manibe37
    @Manibe37 Před 9 lety +3

    Can stars be purple? Because I heard that there can be stars that produce light of two different colors at the same part of their life (at the same moment), so what if there is one that produces blue and red at the same time and then it mixes and becomes purple? It would be so cool... XD

    • @carultch
      @carultch Před 2 lety +2

      No, stars cannot be purple. There is a specific spectrum of light that stars produce by virtue of their temperature. If a star is hot enough to glow blue, it will also produce all the visible light colors, and be a bluish white. No matter how hot you make the star, it will never produce a disproportionately higher amount of violet light, to make it purple. There is a limit to how blue a star can get, from the bluish white color that form stars like Rigel.

  • @white_shadow_123
    @white_shadow_123 Před 9 lety

    Beautiful video.

  • @Lopoi
    @Lopoi Před 9 lety +2

    Thanks snow... and audible

  • @lauraskujyte6954
    @lauraskujyte6954 Před 9 lety +3

    I saw Pink Floyds album Dark side of the moon reference is this video!:)

    • @isabellev9576
      @isabellev9576 Před 7 lety

      Laura Skujyte It's probably not a reference, that's just how a prism looks.

    • @yodasippin1317
      @yodasippin1317 Před 6 lety

      QsfProductions Games Machinimas And More! No it DEFINITELY is a reference lol

  • @TristanJCumpole
    @TristanJCumpole Před 9 lety +4

    I just looked outside and my sky is black.

  • @AmoebaMan23
    @AmoebaMan23 Před 9 lety

    I chuckled at that picture of biscuits/gravy at the end there. Oh, the not-so-fond memories of one of every three breakfasts for 5 months of my life...

  • @anthonyh137
    @anthonyh137 Před 9 lety +1

    Being an optics major, it's not often i learn something in the realm of optics from a source like this, but this explanation is genius.

    • @User-jr7vf
      @User-jr7vf Před rokem

      Hi Samantha. I study physics for fun and I'm having a hard time explaining the color pattern of the sky with Maxwell's Equations.

  • @luxtenax9175
    @luxtenax9175 Před 9 lety +14

    Am i the only one who thinks that the Gravy looks gross as hell? :s

  • @samramdebest
    @samramdebest Před 8 lety +7

    I don't get why computers can't show all the colors

    • @Monochromicornicopia
      @Monochromicornicopia Před 8 lety

      +samramdebest
      Because showing "all colors" would involve every wavelength (impossible) and every combination of wavelengths (ultra impossible). There are an infinite number of colors. Computers can't handle "infinity".

    • @samramdebest
      @samramdebest Před 8 lety

      Monochromicornicopia
      I meant why computers can't show all visible colors to a reasonable colors. Like if they had theoretical infinite range on the 3 colors they emit. Maybe I meant that not all (visible) colors are expressible as RGB values

    • @Monochromicornicopia
      @Monochromicornicopia Před 8 lety +7

      samramdebest
      True. That's because not all colors can be made using RGB combinations.

    • @CodNeverEnds
      @CodNeverEnds Před 8 lety +1

      +samramdebest A computer can only emit 3 colors. Red, Green, And Blue. All other colors are a combination of those. So if you saw yellow on your screen it isn't technically yellow. It is a combination of other colors to form a fake-yellow or pseudo-yellow.

    • @stellarfirefly
      @stellarfirefly Před 8 lety +3

      +samramdebest The simple explanation is that the chromaticity diagram is not a triangle, and remember that the diagram is as Henry says, the colors visible to most humans. When expressing colors as a combination of 3 values, it is only possible to display colors that would be graph-able as a triangle on that chart. Hence at about @0:57 in the video, the "computer monitor gamut" is a triangular subset of the whole graph.

  • @dylanhiscok2284
    @dylanhiscok2284 Před 9 lety

    I never even asked that question until I saw the title of this video, thanks for teaching me something new.

  • @AlkisGD
    @AlkisGD Před 9 lety

    2:43 - That's one of my favorite non-fiction books! :D

  • @lucigallagher5542
    @lucigallagher5542 Před 9 lety +3

    Hooray for Pink Floyd refrance

  • @snazzysnake5051
    @snazzysnake5051 Před 7 lety +12

    Why aren't there people with white as there favorite color?
    (Unless you are, then tell me, thanks)

    • @juliewinchester4799
      @juliewinchester4799 Před 7 lety +9

      because white is so fucking boring

    • @snazzysnake5051
      @snazzysnake5051 Před 7 lety +1

      Joshua Wood k den

    • @MaiNguyen-ik6ew
      @MaiNguyen-ik6ew Před 7 lety +1

      Whites my favorite color

    • @Kwaj
      @Kwaj Před 7 lety +2

      l Iove white in conjunction with other colors, especially when it's nicely paired up with royal purple; it's a magnificent combination. I also have an affinity for white, gray, and black together because even colorless schemes have their own unique beauty.

    • @yairkornblau9440
      @yairkornblau9440 Před 7 lety +4

      Because most people aren't six years old and we don't have a favorite color

  • @plica06
    @plica06 Před 9 lety

    I just wanted to say it was such a relief he didn't overly pronounce his T's in this video unlike usual.

  • @MrAndrejck
    @MrAndrejck Před 9 lety

    One of the best boosk imho! :D

  • @stranger9774
    @stranger9774 Před 4 lety +4

    some annoying kid: tHe skY iS bluE becAuse the ocEan reFlects bLue

    • @mcvibing2785
      @mcvibing2785 Před 3 lety

      my ex-dad used to say that and I believed it for a while

  • @automaticBRO
    @automaticBRO Před 9 lety +4

    Im legally blind...

    • @stabileseitenlage
      @stabileseitenlage Před 9 lety +24

      Well, at least you're not illegally blind. ;) jk I'm sorry for you...

    • @VortexxFX
      @VortexxFX Před 9 lety

      why are you on youtube then?

    • @CrossHarry
      @CrossHarry Před 9 lety +1

      VortexFX because some ppl who arelegally blind acn still use computers with magnification.

    • @nihilistteddy3
      @nihilistteddy3 Před 9 lety

      So you can't see?
      Wait for it.... lol

    • @automaticBRO
      @automaticBRO Před 9 lety +2

      Jokes on you, I have no name Bruh i have a license for being legally blind.

  • @zoravursingh5617
    @zoravursingh5617 Před 9 lety

    Omg I'd love to know more about this

  • @Peter_1986
    @Peter_1986 Před 4 lety +1

    "Purple Sky" sounds like an awesome name, to be honest.

  • @thepropolys
    @thepropolys Před 9 lety +11

    These videos would be so much better without the evolution propaganda. I saw the other day you made it through a whole video without mentioning such unsupported views... I think you know it's unnecessary.

    • @30LayersOfKevlar
      @30LayersOfKevlar Před 9 lety +80

      Here we go again.

    • @Syncopad
      @Syncopad Před 9 lety +45

      Trololololo

    • @callieeraee
      @callieeraee Před 9 lety +51

      Are you suggesting that evolution is false? Cause I think that if you're watching a SCIENCE channel you may get some scientific content in it...

    • @mmmodafoca
      @mmmodafoca Před 9 lety +59

      You know what, Yeah you're right, I wish Minutephysics would stop with the unnecesarry propaganda. I dislike the fact that he claims the sun revolves around the earth, That is totally un-acceptable to my fellow Geocentrist Brethren. And while we're ad it, Jesus never spoke of gravity, keep that witchcraft out of our childrens education!

    • @thepropolys
      @thepropolys Před 9 lety +2

      callieeraee I'm suggesting that the evolutionist view is not supported by observation, but is only supported by fabricated construct of interpretation. Since this video is about observation, it is not consistent to bring up irrelevant theories that are not backed by direct evidence.

  • @isaac10231
    @isaac10231 Před 9 lety

    Nifty! I like it!

  • @fartzinwind
    @fartzinwind Před 9 lety

    Now I want biscuits and gravy, but I'm at work, on a holiday.... thanks minute physics.

  • @Husgum
    @Husgum Před 9 lety

    thank you for the video :)

  • @brianpso
    @brianpso Před 9 lety

    Thanks to your last videos I've finally understood the reasons behind the color of the sky, so thank you, really =)

  • @MrHuichuan
    @MrHuichuan Před 9 lety

    omg, you are so amazing!

  • @TrafficConeSnail
    @TrafficConeSnail Před 9 lety

    Child: Why is the sky blue?
    Mother: BECAUSE GRAVY!!

  • @sacktheargonian
    @sacktheargonian Před 9 lety

    OH YES FINALLY!!!! This video taught me a thing I wanted to know, but didn't know how to look up, and corrected me on a thing I was actually telling a friend about earlier today!

  • @yatagarasu9274
    @yatagarasu9274 Před 3 lety +2

    I'm less confused and more confused at the same time

  • @better.better
    @better.better Před 9 lety

    All of Bryson's books are great!

  • @davidalearmonth
    @davidalearmonth Před 9 lety +1

    A Short History of Nearly Everything by Bill Bryson was the first audio book I ever downloaded, and I still consider it to be one of the best I've ever listened to. I recommend it to everyone! :)

  • @cheungsteven2682
    @cheungsteven2682 Před 4 lety

    Great explanation on the origins of different colours as mixtures of different portions of monochromatic lights using the chromatographic diagram! And I did learn the reason for why stars are not purple in colour with the thermal spectrum. It might even be better if the effect of scattering by the Earth's atmosphere to the sun's original spectrum is shown at the end. That will be a more explicit way of showing that scattering (by the atmosphere) cannot modify the spectrum in a way that gives the "right" proportion leading to purple/violet, and hence the sky is not purple/violet. Great thanks!

  • @TheBoulder11
    @TheBoulder11 Před 9 lety

    "Hey Dad, why is the sky blue?" "Well son because it's basically gravy."
    gotta love science

  • @Mammothgravitybattles
    @Mammothgravitybattles Před 9 lety

    super fantastic

  • @griffingoodman1055
    @griffingoodman1055 Před 8 lety

    Explained pretty well to me

  • @huxley8671
    @huxley8671 Před 4 lety

    I've watched so many of their videos in just one night, I now have information that I don't know where to use

  • @ElectronicTonic156
    @ElectronicTonic156 Před 9 lety +1

    In the inverted color sequences of your video, Henry, how do you get your hand to appear fleshy tones? Fancy editing, or do you just paint your hand blue?

  • @ainsleybreakenridge6293

    When my future children ask why the sky is blue, I shall respond "Because gravy"

  • @alpratsibz
    @alpratsibz Před 9 lety

    Great!

  • @tessat338
    @tessat338 Před 9 lety

    I read Bill Bryson's "A Short History of Nearly Everything" when I was in the hospital in labor and then after my son was delivered. I figured it would be that last chance I'd have to read a grown-up book for awhile. It really passed the time and distracted me from discomfort.

  • @shreshtha786
    @shreshtha786 Před 8 lety

    Minute physics is the only channel i watch non stop although i don't get a word he says...yeah but the drawings are really cool

  • @StuffIwannaRemember
    @StuffIwannaRemember Před 6 lety

    It's not just cuz I'm hungrry, but electromagnetic gravy is genius henry!

  • @JumpyPlum9613
    @JumpyPlum9613 Před 9 lety

    Had it not been for that electromagnetic gravy analogy, I might have never quite grasped this concept.

  • @isaacmak1234
    @isaacmak1234 Před 9 lety

    thx for sharing :D

  • @AtticusEdwards
    @AtticusEdwards Před 9 lety

    ELECTROMAGNETIC GRAVY
    Thanks for the song name, Henry!

  • @bonnievale1421
    @bonnievale1421 Před 9 lety

    I find this insuring very

  • @wonderwhatchannel
    @wonderwhatchannel Před 9 lety

    That was very cool :)

  • @sophiesmith9300
    @sophiesmith9300 Před 3 lety +2

    Ok,but why do I see the sky as a different color than my friends? Sometimes it looks really purple and I'm like "Wow look at the sky it's so purple!" And they're like "Wtf no what are you talking about?" I'm not colorblind, I can see all the colors normally, but why does the sky look purple-blue to me?