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Help! Evil physiology problem

  1. Oct 3, 2004 #1
    evil physiology problem

    here's a really evil physiology problem:
    Why is it when people watch a movie, they see a continuously running picture, when really a movie is composed of a set of still frames? What physiological process is involved in this?

    I really am stuck on this one, and I would appreciate it if anyone can help me! Thanx!
  2. jcsd
  3. Oct 3, 2004 #2
    I don't know the physiology of it, but I guess real life is the same thing as a movie. Any movement you make is really comprised of a set of smaller movements. Nifty.
  4. Oct 3, 2004 #3
    P.S. I could give you the answer "oh beause the frames move faster than you can recognize, so it just looks fluid because it's like 30 frames a second or whatever", but I'm sure you are looking for a better answer than that :)
  5. Oct 3, 2004 #4

    Thanx! I really appreciated the help!
  6. Oct 3, 2004 #5
    Your brain fills in the gaps.
  7. Oct 4, 2004 #6


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    It's even worse if you watch color TV. All that is really there are three very small tiny round dots. One red, one green and one blue. The rest of the screen is black.
    It is the response time of your eye that does the trick.
    Light triggers a chemical cascade that your brain ends up interperting as light.
    That cascade take time to complete and then reset.
    Any changes that occur after the cascade starts are ignored.
    Note that for a movie there is a black frame that appears while they move a new picture frame into place for viewing. This is done because you would actually notice
    the movement otherwise. Black is no light so it does not trigger any new cascades.
    Hope this helps.
  8. Oct 4, 2004 #7


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    The short answer is neural firing rates. Perception appears to be analog at more than about 20 frames per second.
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