Why is it Dark at Night?

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  • čas přidán 3. 06. 2024
  • Have you ever wondered why you look up and see a dark sky at night?
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    Created by Henry Reich Created by Henry Reich
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Komentáře • 10K

  • @KiDxNyu
    @KiDxNyu Před 8 lety +2199

    The answer is obvious, its dark so you can sleep better.

  • @davidmb1595
    @davidmb1595 Před 8 lety +923

    When I saw the title I was like "This is so obvious, any 3 year old knows it" After a minute of starting watching it, I was like "Shit, I don't know shit"

    • @michaelunderhill5497
      @michaelunderhill5497 Před 8 lety +3

      XD Same

    • @paolopatron5411
      @paolopatron5411 Před 7 lety +69

      More like "lol I know this stuff" then he goes "actually, it's not that, there's this other explanation" then when I go "ohhh that makes sense" he goes "actually, that's not it either, here's another explanation" then he does this three more times

  • @invertedgames7993
    @invertedgames7993 Před 7 lety +817

    yes, inject the knowledge into my veins!

  • @cloviscareca
    @cloviscareca Před 9 lety +450

    Vsauce, Minutephysics, Periodic videos.....
    An incredible and unbelievable playlist for the weekend :)

  • @AldirneXd111111
    @AldirneXd111111 Před 10 lety +1037

    SO if aliens are observing us they see a dinosaur?

    • @InvokingPeace
      @InvokingPeace Před 10 lety +170

      pretty much

    • @ghostlourde2700
      @ghostlourde2700 Před 10 lety +42

      Unless we figure out how to time travel. then they might see us looking at the dinosaurs. or perhaps we time travel to stop ourselves from time travelling, 1 + -1 style.

    • @gabepatton9851
      @gabepatton9851 Před 10 lety +23

      ***** Although, because of the motion of the Galaxy/Solar System/Earth, time travel would have to include some way to account for literally everything in the universe, as well as a way to get to the earth to actually see it during that time, instead of just the point in space that earth is in the time you're travelling from. Furthermore, we would have to measure the speed and direction of everything in the universe also, to find where it was/will be or else we run the risk of traveling to a time during which the place that you are now was in fact occupied by some asteroid. This would likely result in the destruction of what is known as you, as all of the electrons/neutrons/protons that you are made up of would be scrambled among those that made up said asteroid, and this would cause the creation of new particles as all of the electrons ... etc mixed and combined in ways that neither your bod nor the asteroid had them in before. Basically, time travel would be extremely dangerous without a dizzying amount of math.

    • @keithvrotsos3843
      @keithvrotsos3843 Před 10 lety +23

      That appears to be the train of logic implied... so I guess.

    • @MaxoRedstoneo
      @MaxoRedstoneo Před 10 lety +5

      i think, as far as i know

  • @beccasiciliano931
    @beccasiciliano931 Před 11 lety +18

    I asked this question in my 8th grade science class. My teacher didn't have an answer. A few years later I asked my dad. We thought about it and this is the answer we came up with. I am so excited this video exists because I've been asking this question for years. Thank you.

  • @adrianshuh-humphries3915
    @adrianshuh-humphries3915 Před 4 lety +230

    shouldn't ultraviolet and x-ray light from ultra-distant stars get redshifted into the visible spectrum?

    • @sodr7440
      @sodr7440 Před 4 lety +10

      Oh yes ????

    • @sodr7440
      @sodr7440 Před 4 lety +36

      May be there is a lot less ultraviolet light than infrared? so when they redshift to visible spectrum, they remain not intense enough for us to be able to see it

    • @mikethespike056
      @mikethespike056 Před 4 lety +1

      Wow

    • @kenivia9476
      @kenivia9476 Před 4 lety +19

      probably would just look like a normal star to naked eyes tho cos they must be like super distant

    • @dreamyrhodes
      @dreamyrhodes Před 4 lety +69

      It does. The quasars we see from almost 13 b light years away are radiating heavily in the UV and X-Ray spectrum but we still see them all red. And the backgound light is shifted even more, into microwaves. That's why the cosmic background is a microwave background which equals a temperature of 3.15 K or -270°C so all the light from the big bang reaches us as 3 K radiation.

  • @davidshtayfman752
    @davidshtayfman752 Před 10 lety +26

    This is a lot better than the 10 second videos.

  • @h4happy309
    @h4happy309 Před 6 lety +22

    Videos like this are the reason why I LOVE physics 💚
    Thankyou for the great work!
    continue doing so :)

  • @CupojoePro
    @CupojoePro Před 10 lety +49

    2:26 is not to scale children!

  • @missingpatel7349
    @missingpatel7349 Před 4 lety +6

    This is the only channel which gives me answers about cosmos without giving me existential dread

  • @debmalyaroy5870
    @debmalyaroy5870 Před 6 lety +3

    One of the best videos I have ever seen. This channel is so wonderful. Great job!

  • @Yves_Zhou
    @Yves_Zhou Před 8 lety +489

    i am even more confused after i finished watching this vid, sos

    • @yjk92
      @yjk92 Před 7 lety +28

      Well, you know a lightyear is the amount of distance light travels in one year, right? So if you look at a star 1 lightyear away, you get the image of the star with 1 year delay, since the light you just got started traveling 1 year ago. if a new star popped up 2 million years ago, but the distance between this star and our Earth is 1 million lightyears, we still need to wait 1 million more years for that light(the image of the star) to arrive. That is why we can't see a lot of stars that certainly exist. Light is so slow that it takes time to reach us.
      Also many stars' light is out of our visible spectrum. Kinda like how some animals can hear sound that is too high or low for humans to hear, there are light that only machines can see.

    • @Newstory737
      @Newstory737 Před 7 lety +8

      Light is fast I believe.. Just the space between the star and our planet seems to be very, very big :)

    • @yes12337
      @yes12337 Před 7 lety +6

      light is a wave, yes? So then imagine throwing a stone in the Pacific Ocean and waiting to see the wave on the coast of Europe.

    • @gabrielbrady1471
      @gabrielbrady1471 Před 7 lety +1

      the reason its dark is because the universe is infinitely large and growing that the light from the big bang hasn't reached us yet but when it does the night sky will be light if that makes any sense to you if it don't forget everything that I just said

    • @samihaislam3487
      @samihaislam3487 Před 7 lety +5

      Infrared radiation is outside of our visible limit. Humans cannot see it.

  • @mrvlhs
    @mrvlhs Před 10 lety +6

    This was amazing. I never really got a reason to admire astronomy but this is a great one, thanks! :)

  • @ricochet188
    @ricochet188 Před 9 lety +109

    I can't believe I never knew what the term "infrared" actually meant until now.

    • @ricochet188
      @ricochet188 Před 8 lety +7

      I got that from the video. Thankyou.

    • @rescuecatHQ
      @rescuecatHQ Před 8 lety

      ***** so what is microwaves?

    • @pyramidblack
      @pyramidblack Před 8 lety +4

      +Julien12150 thanks wiki

    • @Sontraid
      @Sontraid Před 8 lety

      Is there a wavelength higher then 1 meter? Like 2 meter or even a kilometer?

    • @pyramidblack
      @pyramidblack Před 8 lety +2

      +Sontraid 10 m is decimeters but its rarely used 100 is hektometers and 1000 is kilometers

  • @haiggoh
    @haiggoh Před 10 lety +70

    I want infrared vision :(

  • @Keredx89
    @Keredx89 Před 10 lety +45

    Hold on a second! Wouldn't the redshifting get the ultraviolet radiation from distant stars and galaxies into the visible spectrum in a similar way? So what's going on there?

    • @muthukumaranl
      @muthukumaranl Před 5 lety +1

      i have the same doubt too..

    • @passthebutterrobot2600
      @passthebutterrobot2600 Před 5 lety +1

      That's a very good point! Anyone know?

    • @deadat2
      @deadat2 Před 5 lety +1

      Well sure it's just that the range of visible is fairly small Red700nm-violet400nm. Redhift is just the measurement of the change in wave length of light that say a hydrogen atom emits divided by it's rest wavelength. So really the question is kind of irrelevant with the scales we are talking about anything close enough to be in the visible spectrum is to close to matter.
      skyserver.sdss.org/dr1/en/proj/basic/universe/redshifts.asp
      www.space.com/25732-redshift-blueshift.html
      science.nasa.gov/ems/09_visiblelight

    • @vornamenachname5267
      @vornamenachname5267 Před 4 lety +9

      You are right, but the ultraviolet radiation from even more distant stars gets redshifted even more. Therefore it too becomes infrared. So there is a zone where you can see the 'ultraviolet' light, but farther away, you can't.

    • @MrLaptopus
      @MrLaptopus Před 4 lety +2

      Good question. This video is false and just a misdirection into Big Bang, etc. The reason the sky is dark is because density of light reaching us is low.

  • @susanlegeza7562
    @susanlegeza7562 Před rokem +3

    Love these to the point explanations!!!

  • @lauralopezbueno535
    @lauralopezbueno535 Před 10 lety +3

    This is almost unbearably beautiful. Thanks!

  • @Poulpink
    @Poulpink Před 7 lety +1

    Very nice, I've always been wondering at this question and this perfectly explains it

  • @demonhunter505
    @demonhunter505 Před 10 lety +4

    Yes. I saw a picture sometime (an artist's rendition I think, or maybe a simulation) that basically measured the strength and wavelength detection of the creature's (I think it was a lizard or chameleon of some kind) eyes and then took a picture of the night sky with those wavelengths, combined it with visible light (I think it sees in the spectrum we see, along with infrared) and vuala. You'd have to do some searching for it, but if I remember the article right, that sums it up.

  • @zwz.zdenek
    @zwz.zdenek Před 10 lety +4

    You forgot one piece of the mosaic - there is actually a "border" beyond which we cannot see. It is where the expansion reaches the speed of light from us. The area of this sphere is said to contain all of the entropy information in our observable universe. There is no classic hard barrier, but the laws of physics make it so that we cannot ever see or get past it.

    • @shabsi770
      @shabsi770 Před 9 lety

      למעלה מגלגל התשיעי, אין שם לא מקום ולא רקות.

  • @gooseberry_disliker
    @gooseberry_disliker Před 2 lety

    this is one of the best explanations i've come across.

  • @gretchenjansen7562
    @gretchenjansen7562 Před 10 lety +2

    this was both educational and strangely adorable, thank you!!

  • @MichaelBernardo
    @MichaelBernardo Před 10 lety +3

    Haha what a great way of looking at it no pun intended. I never thought of that. Great video.

  • @Sinan97082
    @Sinan97082 Před 8 lety +55

    BRAINGASMS!!! I love this stuff, it stimulates my brain somehow. Started to study again with 30 and I would recommend to others too who feel stuck in life or in their job and generally considers learning as a never ending process and enjoys it.
    Thanks to all the people who do this stuff (Vsauce, RSA, MinutePhysics, FightMediocrity, Brian Johnson, Elliot Hulse and so on)
    Any Recommendations refering to similar Videos? Education, Psychology, Self Development, ... would be apreciated.

    • @Huu159
      @Huu159 Před 8 lety +3

      Try In A Nutshell/Kurzgesagt

    • @Sinan97082
      @Sinan97082 Před 8 lety

      Akshay 28392 Warum kurzgesagt?

    • @Huu159
      @Huu159 Před 8 lety +1

      +Sinano That was the earlier name of the channel. They explain big concepts in short videos hence "kurzgesagt"

    • @ash.junaid
      @ash.junaid Před 8 lety +2

      +Sinano Good to hear it man. I'm kinda in a similar situation right now. Check out Numberphile as well. Can't recommend it enough =)

    • @Sinan97082
      @Sinan97082 Před 8 lety

      Akshay 28392 Vielen Dank für den Hinweis :)

  • @abilashbrian4997
    @abilashbrian4997 Před 7 lety

    Wow.....this is awesome.....I appreciate it minutephysics

  • @eu_lan
    @eu_lan Před 10 lety

    very interesting good job henry!!

  • @Spinodal23
    @Spinodal23 Před 3 lety +3

    2:57 Korean Subtitles Typo - "자외선" should be "적외선"

  • @Roxanewolfie
    @Roxanewolfie Před 10 lety +61

    does this mean if we could perceive infrared light with our human eyes, the sky WOULD be full of light at all times?

    • @TheThundercool
      @TheThundercool Před 9 lety +19

      It means that, if we were able to see in a wider spectrum of light (e.g. infrared, ultraviolet, or more), we would see many other things that are invisible to our current capacities...

    • @Evan_Case
      @Evan_Case Před 9 lety +2

      If we could see in Microwaves you would see the CMB (Cosmic Microwave Background) everywhere....

    • @KasisnuSingh
      @KasisnuSingh Před 9 lety +5

      Actually you would have to wait a really long time! There would be stars that are far enough that light from them hasn't reached us yet!. The background radiation would be visible as well.. something. A lot depends on how we would actually perceive the radiation. I assume you assumed there was no atmosphere! :)

    • @nicolasiguaran
      @nicolasiguaran Před 9 lety

      Tethloach Kingofreason Ehmmm. I may think you are wrong. The thing the haets up the earth is not the light, it is the infrared thingies. That we could see them doesn't mean there would be more of it and so the earth's temperature would stay the same. It would be a lot lot brighter, though.

    • @KasisnuSingh
      @KasisnuSingh Před 9 lety +2

      Tethloach Kingofreason Not quite. The light spreads out. The further away we are, the less intense it actually is.
      nicolasiguaran You're close. So both infrared and "light" are the same thing here. *We* can see one and not the other. And thanks, my comment above was partly flawed. Updated!
      Also, we need the atmosphere for the earth to *stay* warm. Think of other planets or the moon. It can get quite warm during the day but then also quite chilly at night. The reason that happens to a lesser degree on earth is due to the presence of greenhouse gases(in the atmosphere).

  • @jonni2734
    @jonni2734 Před 6 lety +1

    Awesome video!!!

  • @ebinjayan
    @ebinjayan Před 9 lety

    this clears up so much..thank u

  • @MeronBridgeMR
    @MeronBridgeMR Před 8 lety +4

    This is awesome, I never thought that a certain wavelength light emitted from a moving star would actually appear as another wavelength to us I assume that is because of the Lorentz transformation... but if so shouldn't the wavelength actually "become" shorter relatively to us?

    • @MeronBridgeMR
      @MeronBridgeMR Před 8 lety

      (Like becoming UV instead of IR)

    • @patrickhector
      @patrickhector Před 8 lety

      As space grows, the spaces between everything grows. This includes the space between different adjacent waves in a beam of light, essentially making the wavelength longer. Another thing is that as objects creating any sort of wave moves away from an observer, the individual waves are made farther apart, making the wavelength longer. What you're thinking about is *blue*shift, so named because when an object is moving toward an observer fast enough, any light released appears slightly blue because the individual waves are released closer together.

    • @MeronBridgeMR
      @MeronBridgeMR Před 8 lety

      +Patrick Hector That makes sense. Now I have to explore this topic further :D Thanks!

  • @coasterrick
    @coasterrick Před 9 lety +20

    damn I wish I was brainy so I could understand this stuff. If they teached this in school id of listened all I remember doing in physics is connecting a fucking battery circuit to a few little bulbs

    • @ErojFeeding
      @ErojFeeding Před 9 lety +1

      Its not that hard you just have to understand the basics at first :P

    • @LucaPed94
      @LucaPed94 Před 9 lety

      Slick Rick Taught*

    • @ree83ce
      @ree83ce Před 9 lety

      Could be worse + Slick Rick all I do in science is burn stuff ( ussually salt water or something else added to pure water that that dose or dose not dissolve in it ) to learn diffrent things like, why salt dosent evaporate or how to get clean water or somthing wired, I mean, dont get me wrong, you put fire into a lesson, I aint complaining.... unless I get burnt by the fire then ill be a little mad lol

    • @dee8163
      @dee8163 Před 7 lety

      tell me about it. we keep learning about how light gets reflected or refracted by glass, mirror etc etc

    • @meryemrashidova5984
      @meryemrashidova5984 Před 6 lety

      This is what we are learning in Physics just now

  • @alfahim9iner
    @alfahim9iner Před 9 lety

    One of my favorite videos

  • @horiama
    @horiama Před 10 lety

    Awesome video!!!!!! Best one I have seen yet~ REALLY blew my mind with science :)

  • @domishbk
    @domishbk Před 10 lety +3

    Lean back :)

  • @MoAli72
    @MoAli72 Před 10 lety +48

    I still don't get it.

    • @lars123mc
      @lars123mc Před 10 lety +31

      my mouth: intresting
      my brain: durrrr

    • @shynnsup8383
      @shynnsup8383 Před 10 lety +4

      Red Shift. Thats all you need to know.

    • @MoAli72
      @MoAli72 Před 10 lety

      Shynn Sup Now I need to know what 'Red Shift' is... :s

    • @shynnsup8383
      @shynnsup8383 Před 10 lety +1

      Mohammed Ali
      Light changing its wavelength into infrared.

    • @vottoduder
      @vottoduder Před 10 lety +2

      Mohammed Ali Red shift is the same concept as when you hear a police car siren traveling away from you except in the form of light waves instead of sound waves.

  • @GaurabPaudelja
    @GaurabPaudelja Před 10 lety

    Thanks for this informative video. I will surely share this to my school friends.

  • @DadoFrk
    @DadoFrk Před 10 lety

    Very good and quick explanation

  • @Broockle
    @Broockle Před 9 lety +3

    Stars that are super far away also become etremely dim by the time they reach earth so that our human eyes couldn't see them even if their light was in the visible spectrum.
    We would still need telescopes to see them anyway.

  • @purplepeoplepurple
    @purplepeoplepurple Před 10 lety +6

    A good explanation, if a little hurried. The music, though, was a distraction - too loud.

    • @Pierrot110194
      @Pierrot110194 Před 10 lety +24

      Well, the channel is called "MinutePhysics"...

    • @jameslolan829
      @jameslolan829 Před 9 lety +4

      Peter Pepper yeah not "HourPhysics" explaining every single fact about one thing!

  • @Petch85
    @Petch85 Před rokem

    This is one of my favorit videos on youtube. I love it so much.😍

  • @holygod3717
    @holygod3717 Před 6 lety

    Excellent explanation

  • @elenaalex4588
    @elenaalex4588 Před 8 lety +74

    what a complicated answer for a simple question

    • @BrickBuster2552
      @BrickBuster2552 Před 8 lety +82

      "Y me no see night?"
      "2 red"

    • @Titanic-wo6bq
      @Titanic-wo6bq Před 8 lety +1

      dat explains it

    • @EmilioKolomenski
      @EmilioKolomenski Před 7 lety +8

      Start your own science channel, you can call it "SecondPhysics"

    • @gangstermedia9039
      @gangstermedia9039 Před 7 lety

      because it is all bullshit

    • @raghavnandyal1518
      @raghavnandyal1518 Před 7 lety

      It's that simple. It's something called the Oliver's paradox, which is still unsolved. It basically says, if there's an infinite number of stars, then why is there light in every direction you look?

  • @alexcondurache
    @alexcondurache Před 10 lety +7

    a question .. if I'm on earth and you are on a planet one light-year away from me, and suddenly your planet explodes, but you're sending me a voice message in the exact time .. what reach to me first? your voice, or the light from the explosion?

    • @BenjaminStewart6
      @BenjaminStewart6 Před 10 lety +13

      It depends on how the voice message is being sent. If it is radio or any other form of communication that uses the electromagnetic spectrum, then my voice being cut off would happen at the exact same time as the explosion, since light and radio waves are both on the electromagnetic spectrum.

    • @aaronreid5789
      @aaronreid5789 Před 10 lety +26

      his body would reach u first lol

    • @mahmouduthman382
      @mahmouduthman382 Před 10 lety

      Benjamin Stewart true, but given that the sound was send in the form of a message transmitted using electromagnetic radiation shouldn't it take extra x time to encode & decode the message content back into sound (Voice) ?

  • @godnyx117
    @godnyx117 Před 9 měsíci

    Good old LEGENDARY early 10s!!!! The best period for someone to be alive!
    Amazing video my friend!

  • @csApollo11
    @csApollo11 Před 7 lety

    Thank you for the great video!

  • @number0017
    @number0017 Před 10 lety +7

    I always thought because the dark matter clouds cover a ton of light or bends light lol

    • @RICE4azns
      @RICE4azns Před 10 lety +9

      It's not called Dark Matter because it's dark. It's called Dark Matter because it is utterly invisible across all spectra of light, only detectable by its gravity. Galaxies are formed at dark matter clumps, so if anything, all the gravity would bend light into galaxies, enabling viewers to see more light.

  • @CatalystEXE
    @CatalystEXE Před 10 lety +6

    interadesting

  • @mercybellafiore3677
    @mercybellafiore3677 Před 10 lety

    I can listen to your voice all day... You have great information in your videos, and since I have synethesia, your voice smells like the beach. And I love the beach.

  • @sohailansari2673
    @sohailansari2673 Před 7 lety

    MAN! where do you get this sort of information? You truly deserve a nobel.

  • @mmartinisgreat
    @mmartinisgreat Před 7 lety +20

    question. can some one be looking back in time at us??

    • @Poulpink
      @Poulpink Před 7 lety

      yes

    • @pozpoz2126
      @pozpoz2126 Před 7 lety +3

      fuck

    • @RichardPugsley
      @RichardPugsley Před 7 lety +1

      So if we had a way to travel really fast to another place far from earth and than look at a certain place on earth, we could see who commited a murder for example...

    • @carloshgrant
      @carloshgrant Před 7 lety +3

      so to answer you question simply, yes. if you go one light year away from earth and if you could look at it with a telescope, the image you see is 1 year old. it looks like you are watching live events on earth (clouds moving and all) but it all happened one year before. thats just because light has a finite speed and it takes time for it to travel.

    • @dmmm876
      @dmmm876 Před 7 lety +3

      Yeah, as Carlos Grant said, 'if you go one light year away from earth and if you could look at it with a telescope, the image you see is 1 year old'. The only problem with doing it: it would only really work if we could instantly teleport one lightyear away, or if we could travel faster than the speed of light. Because we'd need to travel a lightyear away from the Earth faster than the light itself can get there.
      For example, if we have a race and you start a month earlier than I do, I'd need to drive much much faster than you are, otherwise I'd never catch up.
      The same sorta thing applies here. To see even a month into the past, we'd need to travel impossibly fast to catch up with the light that got sent out a month ago.
      It's still cool to think about though.

  • @osoco7294
    @osoco7294 Před 9 lety +4

    ERROR IN THIS VIDEO?
    "If we lived in an infinite, unchanging universe, the entire sky would be as bright as the sun."
    Excuse my english, but my small brain tells me that's not how it goes at all. In my opinion, the most important thing is ratio between bright objects empty (lightless) space. Emptiness wins - big time. I also think that - in this context - this is also the most important thing in real, expanding universe, and red shift effect starts to affect in VERY distant objects. If the red shift were the main reason, we should see dark red(ish), not black background.
    Feel free to correct.

    • @jamescarwyncandila8044
      @jamescarwyncandila8044 Před 9 lety +1

      OSOCO Yes? I agree in some part of your opinion. And that it is in the last part of it. We would see some kind of a dark reddish thing. Yeah, we will be able to see some dark reddish thing. But not the whole background of it. Because, As something gets redder, it gets more... well.. dark. And as it reach it's point where literally it's infrared. It would become, black. Because we cannot see it anymore. But if the theory was true, (The theory that I'm talking about is the Infrared thing.) Some animals like boas, will see the night with a lot of red stuff but not totally all. Because some far things are so infrared, that even animals that can see them, won't be able to see them. I hope you get my point.

    • @osoco7294
      @osoco7294 Před 9 lety

      Jemas Dilacan
      That's pretty much how I think. Anyhow, in my opinion there should be the the whole range of light (because of different red shift levels and distances) from white to invisible infrared added (mixed) TOGETHER, sum total being somewhere between orage and dark red to human eye. That's not the case, so 'emptiness explanation' seems to be WAY more important factor in blackness phenomenon. In that light (no pun intended) there can not be an entity percieving infrared, because of very small percentage of visible objects compared to emptiness in the first place. This is rather hard to explain with my great English skills, lol.

    • @jamescarwyncandila8044
      @jamescarwyncandila8044 Před 9 lety

      OSOCO Nice Englishy things! Anyways, Yeah. You're right. But we don't really know what will be the real factor. But I accept both as a factor. Do you?

    • @osoco7294
      @osoco7294 Před 9 lety

      Jemas Dilacan
      'Sum total' is probably wrong term. 'The result of mixed frequencies' may be more correct.
      "But I accept both as a factor. Do you?"
      Both factors are real and effective, but I don't agree with this: "If we lived in an infinite, unchanging universe, the entire sky would be as bright as the sun."
      That's because of 'emptiness wins' circumstance, thus we don't see the effect of red shift factor in the lack of enough light coming to us in the first place, let alone the dimmer light affected by the red shift.

    • @jamescarwyncandila8044
      @jamescarwyncandila8044 Před 9 lety

      OSOCO Exactly

  • @formidablesloth1806
    @formidablesloth1806 Před 6 lety

    Love you guys!

  • @solocani
    @solocani Před 10 lety +1

    I believe that Cosmic Microwave Background isn't only beyond the stars but simply everywhere in space/time. Anyhow i think you've done a great video, I love it!!! :)

  • @01rai01
    @01rai01 Před 7 lety +4

    olber's paradox

    • @MegaBanne
      @MegaBanne Před 7 lety

      It is BS.

    • @01rai01
      @01rai01 Před 7 lety

      ***** it is, leads to an understanding of doppler shift, cmb, etc

    • @MegaBanne
      @MegaBanne Před 7 lety

      rai ZOR Not realy olber's paradox is based on asumptions that violates the conservation of energy. Some believe that big bang resolved a physical paradox, but there never was any to begin with.

    • @01rai01
      @01rai01 Před 7 lety

      ***** you misunderstand what I'm getting at

    • @MegaBanne
      @MegaBanne Před 7 lety

      rai ZOR ok

  • @wesmo_
    @wesmo_ Před 7 lety +3

    Oudated. Parts of Universe are expanding, other are retracting. Conclusion: We don't know what the hell is going on out there.

  • @masood1362
    @masood1362 Před 7 lety

    you are the best teacher evey i have,, i like the way you explaine and drawing,, plz littel slow down so we undrestand better.. thanks again for everything

  • @matt-kh6it
    @matt-kh6it Před rokem

    Thank you, the video is awesome

  • @hrnekbezucha
    @hrnekbezucha Před 8 lety +12

    So if we would see infrared, sky would be full of stars all the time?

    • @coolipopy
      @coolipopy Před 8 lety +1

      Hrnek Bezucha There are longer wavelengths than infrared

    • @justinlewtp
      @justinlewtp Před 8 lety

      There is a wavelength called far-infared. So the light will be that, as it is moving away

    • @MartinBrada
      @MartinBrada Před 8 lety

      And the cosmic microwave backgroud, as you can see from the name, is microwave.

    • @MrWestSky
      @MrWestSky Před 6 lety +1

      The atmosphere won't let infrared light past through into the Earth, that's the point of it.
      Hubble can take pics of it because it's in outter space. So if we were sensitive to infrared, we'd still see the night sky dark.

  • @williamwatson3703
    @williamwatson3703 Před 8 lety +3

    I thought the reason the sky was dark at because we were so far away from other stars

  • @chinmayasinghrawat4622

    Had always wondered this. Thanks!

  • @emersonsrandomvideos248
    @emersonsrandomvideos248 Před 8 lety +3

    it is dark at night because batman wants it. He is the dark knight.

  • @nora3616
    @nora3616 Před 9 lety +96

    Who else came here from Vsauce?

    • @ahmedalmatari9758
      @ahmedalmatari9758 Před 8 lety +5

      Noura Alzarouni I came here from searching up the best science youtube channels.

    • @69Solo
      @69Solo Před 8 lety

      +Noura Alzarouni Not exactly! I been spying on you for quite a while. So where ever you go, I go. @_@

    • @davetylerii8985
      @davetylerii8985 Před 6 lety

      Noura Alzarouni I came here from Vsauce

  • @ravikgpiit
    @ravikgpiit Před 8 lety

    thanks alot minute physics. i was looking for the answer since long time.

  • @TheAidenSanders
    @TheAidenSanders Před 10 lety

    henryy!!! you are awesome!!!!!!!

  • @thelitcandle7036
    @thelitcandle7036 Před 8 lety +3

    Does dark matter have to do with why the Cosmos is so dark?

    • @breakthewastedspace
      @breakthewastedspace Před 8 lety

      Dark matter is invisible

    • @rizzley980
      @rizzley980 Před 8 lety

      But how can you explain blackhole? Dark matter + particles + vortex .. You can see neither and light can't get pass through it because it is so dark

    • @AlchemistOfNirnroot
      @AlchemistOfNirnroot Před 8 lety

      +Trainer_Poke Doesn't interact via the electromagnetic force*

  • @highseas1036
    @highseas1036 Před 8 lety +5

    I thought I knew shit?!

  • @zthecat
    @zthecat Před 3 lety +1

    This video answered a question I didn't know I had

  • @princesselina6072
    @princesselina6072 Před 7 lety +1

    Omg I love space! It is so cool and it is so fun to know more and more

  • @alecbeach491
    @alecbeach491 Před 9 lety +4

    I DON'T UNDERSTAND!
    THIS MAKES ME ANGRY!

  • @sarukegirl
    @sarukegirl Před 9 lety +4

    brain fart.
    i have to write a two page paper on this. you covered it in 3 mins. and im still slightly confused LOL

    • @MrHorimiya
      @MrHorimiya Před 9 lety

      Geez you're asian, you should understand !

    • @birk7348
      @birk7348 Před 9 lety

      Only 2 pages!?

    • @CrazyDoug17
      @CrazyDoug17 Před 9 lety

      ***** What is an ''Azians'' ?

  • @itsalongday
    @itsalongday Před 5 lety

    In my opinion this is the best video so far

  • @royendemesa6144
    @royendemesa6144 Před 10 lety

    This was beautiful thanks :D

  • @samslostshoe
    @samslostshoe Před 10 lety +3

    NO EDGE!

  • @scotttimothy64
    @scotttimothy64 Před 10 lety +8

    Thanks. Now I won't be able to sleep at night.

  • @SOWMMO
    @SOWMMO Před 10 lety

    This actually helped me understanding the 'Cosmic background radiation' thank you Henry !

  • @mosk204
    @mosk204 Před 10 lety

    love these.

  • @helens.undead666
    @helens.undead666 Před 8 lety +6

    It's not that the dark is at night, it's that when the dark came, people called it night.

  • @amandahiya94
    @amandahiya94 Před 10 lety +31

    i dont understand :( !!!!

    • @quinnbaugh2398
      @quinnbaugh2398 Před 10 lety +13

      As we know space is expanding, the stars are moving away. And the farther they are from us the faster the stars travel. As it goes on and on it becomes redder and redder until we can't see it anymore (at least with a naked eye). That's why it's dark at night, Aman Dahiya. :) : D

    • @metalvinnyofficial
      @metalvinnyofficial Před 10 lety +9

      Humans can't see infrared light.

    • @amandahiya94
      @amandahiya94 Před 10 lety

      Cool Math huh?

    • @flaminggaming4621
      @flaminggaming4621 Před 10 lety +4

      Aman Dahiya Space is always expanding, and the stars are moving with it, and as space gets bigger, and the stars get further away, they become red. As all this happens, space gets bigger, causing the stars to get farther away, making them get redder, they go infrared, which the human eye cannot see.

    • @WJames-nq2df
      @WJames-nq2df Před 6 lety

      Also factoring in the time between when you see a star and when a star is either created or when it dies.
      The blank spots may be home to stars that produce light which will never reach the human eye due to the long distance. And the stars that are there may have died long before humans came around but because they're so far away and the speed of light is so limited, the light those stars shone will be seen long after humans no longer exist.

  • @jeanmessias
    @jeanmessias Před 7 lety +1

    Amazing!

  • @bhaskarpandey8586
    @bhaskarpandey8586 Před 5 lety

    Please make videos on why exactly the red shift is caused , and thanks for this video by the way!

  • @blazinchalice
    @blazinchalice Před 10 lety +5

    I'm pretty sure dust has a lot to do with it, too.

  • @john42t
    @john42t Před 9 lety +16

    There's a simpler reason: The stars are too far away and not bright enough. Virtually all stars the naked eyes can see are in our own galaxy. Even the Andromeda galaxy, which is really close and consists of numerous stars, is barely visible. So the fact that star's aren't visible from the universe outside our own galaxy with the naked eye has barely anything to do with the reasons given.

    • @chakaval100
      @chakaval100 Před 9 lety +2

      Agreed. I think it is like trying to see a candle light miles / kilometers away.

    • @Oinikis
      @Oinikis Před 9 lety +8

      That's not true. For exmaple, if we double the distance between us and a star, we will receive 4 times less light, however, it will take up 4 times less area of our vision, so since they both change at the same rate, when an object is moved away from us it only gets smaller in out field of view, but the brightness density stays the same. For example: if you place a computer screen far enough, you won't be able to see individual pixels, but you could still see the screen. and if you move it so far away you can't see the screen, you can stack screens on top of each other and to the side, and still see them, and if you leave no gaps, it will still have same brightness. This is both beautiful, and scary.

    • @john42t
      @john42t Před 9 lety +1

      Oinikis If you leave no gaps, yes. Space, though, is mostly empty, and even the gap-to-no-gap ratio is "almost all gap".

    • @Oinikis
      @Oinikis Před 9 lety +2

      But if space is infinite and eternal, then there would be no gaps. This prooves universe had a beggining

    • @john42t
      @john42t Před 9 lety

      Oinikis It's an interesting argument. Disregarding speed of light and assuming an average star density, an infinite universe should look infinitely bright.
      I'm pretty confident that the following holds for our universe though:
      Earth is part of a larger galaxy. If you'd look outside the window of a spaceship at a suitable point far away from any galaxy inside the local group, you'd possibly see two faint dots in the entire sky and nothing else (Milky Way and Andromeda).
      If you'd move far away from the local group into intergalatic space, you'd see nothing at all. Complete and total blackness.
      And that even holds if you remain in an area of the universe with a high density in galaxies. Most of the space is located in great voids that are particularly empty.
      So if you move away from our galaxy you usually get into space ever and ever more devoid of stars by orders of magnitude.
      However, that doesn't really refute your argument. Since if, regardless of how far you go, the density of stars remains constant over sufficiently large areas of space (we're thinking truly vast areas of space though), it should still be true that the average perceived brightness should even be infinite (if I think correctly here).
      There is, however, also the speed of light taken into account. The farer you look the more you look into the past. Indeed you can see "light" from all directions in the form of background radiation as talked about in the video.
      So the distance you can see is in fact limited by the age of the universe times the speed of light.

  • @tom7784
    @tom7784 Před 7 lety

    ohhhhhhhhh that clears things up thank you. I was wondering what the answer was, thank you, you have earned a subscriber.

  • @consmos
    @consmos Před 3 lety

    Before digital TV, I used to love turning analogue TVs to static and just basking in the knowledge that I'm watching leftover signals of the big bang, populating throughout space in every direction.
    And also some random noise generated from Earthbound sources, for those pedantic enough to split hairs.

  • @harrybullocks353
    @harrybullocks353 Před 10 lety +4

    Wait. If the universe is infinite in the space it occupies then how can it expand?

    • @freedfighter96
      @freedfighter96 Před 10 lety

      It's not infinite

    • @Alexandra-ip2by
      @Alexandra-ip2by Před 6 lety

      Dun dun dunnnnnnn

    • @seanspacey4452
      @seanspacey4452 Před 6 lety +2

      The idea is that if the universe is infinite, spacetime expands into itself. It's not that easy to visualize and I couldn't find a nice gif but here is a good video that helps:
      czcams.com/video/kV33t8U6w28/video.html
      But the same question can be asked for a universe with curvature. If the universe is not infinite, it would still have to expand into itself because there is no such thing as "outside" of the universe because outside refers to a position and position only exists within our universe because there is spatial dimensions.

  • @Munibahmad241
    @Munibahmad241 Před 9 lety +7

    IN ENGLISH PLEASE? -MINUTEPHYSICS

  • @mjf712000
    @mjf712000 Před 10 lety

    Who ever did the work with the marker is very talented and I enjoyed this video largely due to it. Well done.

  • @magnusmarkling
    @magnusmarkling Před 11 měsíci

    Good one!

  • @LukeRileyA
    @LukeRileyA Před 9 lety +4

    Well, why isn't the sky red then?

    • @marieflynn9420
      @marieflynn9420 Před 9 lety +13

      Luke Riley Because it's infrared which is impossible to see with the naked eye.

    • @coolipopy
      @coolipopy Před 8 lety

      Luke Riley Eh. Rayleigh scattering

    • @janablahova8116
      @janablahova8116 Před 8 lety

      Luke Riley Ha, ha... good qestion

    • @dependent-wafer-177
      @dependent-wafer-177 Před 8 lety

      +Luke Riley Dude really?

    • @dependent-wafer-177
      @dependent-wafer-177 Před 8 lety +1

      +Jana Blahová Erm no not a good question, INFRARED doesn't mean you can see it, infrared is invisible to our eyes like the guy kept on saying in the video jeez

  • @alwaysthelight
    @alwaysthelight Před 7 lety +4

    its because the Dark travels faster than Light

  • @shrap8
    @shrap8 Před 6 lety

    Great video

  • @sachiel197
    @sachiel197 Před 4 lety

    I use these videos to freshen up my knowledge
    and to see if I still remember these things

  • @bigballsgame5591
    @bigballsgame5591 Před 10 lety +17

    Fuck, I didn't know why I wanted to kill myself, until I realized I was in the nerdy part of CZcams.

    • @TheFishCostume
      @TheFishCostume Před 10 lety +59

      I don't understand that, but okay.

    • @bigballsgame5591
      @bigballsgame5591 Před 10 lety

      You can call "science" the theoretical development of techniques meant to improve your sex life. Asking whether the sky is dark or not when, for all intensive purposes, it is and forever will be pitch fucking dark, is not just nerdy, but virgin fucking lame.
      I can't believe how you try to pull me into your fucking lame sad world.

    • @l3orn2Film
      @l3orn2Film Před 10 lety +52

      bigballsgame Nobody tries to pull you into anything, you came here you fuck face.
      Fuck off

    • @Chordseeker
      @Chordseeker Před 10 lety +28

      bigballsgame rofl, you made my day. :D Not sure if joking or trolling, but you are surely free to go spend your quality time improving you sex life then learning something, unless it is less "science" and more "science-fiction" for you. :)

    • @Jaspertt1
      @Jaspertt1 Před 10 lety +12

      Go to your cave... You won't get much more if you don't appreciate this stuff ;)

  • @supertuesday600
    @supertuesday600 Před 10 lety +4

    I don't like his accent.
    He keeps using that irritating tone~ towards the end of most sentences...

  • @juanova5530
    @juanova5530 Před 4 lety +1

    FINALLY,someone who can answer my "out-of-this-world questions"!

  • @ALiJ4LIFE
    @ALiJ4LIFE Před 10 lety

    Beautiful!

  • @sinhaanip
    @sinhaanip Před 9 lety

    Brilliant...