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  • Want to try to explain a physics question?

    If the stars we see at night are millions of years old, then why do we not see the light of stars streaked across the sky?

    Say like a long exposed photo.

    I know there are some very, very smart people here at Poly, I just thought I would ask.

  • #2
    The age/distance is irrelevant. It's the same as any other point source of light - your eyes see it more or less instantaneously, not as a sequence of images retained over time. If you saw starlight streaked, you'd also see streaks of car headlights, lamps in your room, etc.
    When all else fails, blame brown people. | Hire a teen, while they still know it all. | Trump-Palin 2016. "You're fired." "I quit."

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    • #3
      It's because you aren't using enough 'shrooms.

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      • #4
        That too.
        When all else fails, blame brown people. | Hire a teen, while they still know it all. | Trump-Palin 2016. "You're fired." "I quit."

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        • #5
          Originally posted by Docfeelgood View Post
          If the stars we see at night are millions of years old, then why do we not see the light of stars streaked across the sky?

          Say like a long exposed photo.

          I know there are some very, very smart people here at Poly, I just thought I would ask.
          I drank beer. I like beer. I still like beer. ... Do you like beer Senator?
          - Justice Brett Kavanaugh

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          • #6
            Your question is actually on the path to a good question.

            Read up on Olber's paradox.

            This paradox doesn't relate to seeing the light from a star at various times in it's life as a streak but rather that you should see light from every star that ever lived and it should brighten the night sky. Part of the solution is that the universe is expanding. Another part is the finite age of the universe.

            JM
            Last edited by Jon Miller; March 6, 2013, 15:07.
            Jon Miller-
            I AM.CANADIAN
            GENERATION 35: The first time you see this, copy it into your sig on any forum and add 1 to the generation. Social experiment.

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            • #7
              Originally posted by Docfeelgood View Post
              If the stars we see at night are millions of years old, then why do we not see the light of stars streaked across the sky?

              Say like a long exposed photo.

              I know there are some very, very smart people here at Poly, I just thought I would ask.
              Because the relative motion of the stars as compared to their distance is very small. IE, they are moving very fast, but they're very very very far away, so mostly they stay in the same position relative to the earth except over long periods of time (similarly, an airplane 20k feet above you doesn't look like it's moving very fast, even when it's hitting 300mph). Also, the earth is rotating far faster relative to the apparent motion of the stars, so the streaking you do get if you set up a camera with a long shutter is almost all from that rotation (all, probably, since the motion of the star is so little that it is not noticeable on the resolution of your camera).
              <Reverend> IRC is just multiplayer notepad.
              I like your SNOOPY POSTER! - While you Wait quote.

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              • #8
                thank you very much guys

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                • #9
                  Originally posted by Jon Miller View Post
                  Your question is actually on the path to a good question.

                  Read up on Olber's paradox.

                  This paradox isn't that you see the light from a star at various times in it's life as a streak but rather that you should see light from every star that ever lived and it should brighten the night sky. Part of the solution is that the universe is expanding. Another part is the finite age of the universe.

                  JM
                  Isn't the atmosphere too dirty for that to happen, though?
                  Indifference is Bliss

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                  • #10
                    Originally posted by Docfeelgood View Post
                    thank you very much guys
                    Welcome
                    I drank beer. I like beer. I still like beer. ... Do you like beer Senator?
                    - Justice Brett Kavanaugh

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                    • #11
                      at some point all that light is going to get cockblocked byu other big **** floating around

                      like my dick
                      To us, it is the BEAST.

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