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Flag on moon

  1. Feb 29, 2004 #1
    say that you have landed on the moon's surface
    and you held the flag up and started to wave it around

    moon has no atmosphere but has gravity right ?
    than what would flag do when you wave it around ?

    i am guessing that the flag would be stiff but it would be looking down towards the moon because the gravity is acting on it

    any ideas/solutions ?
  2. jcsd
  3. Feb 29, 2004 #2


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    No, it wouldn't be stiff. You could still wave it around, because it has mass and therefore inertia. It won't look quite normal, though, because there is no air to fill it like a sail.

    - Warren
  4. Feb 29, 2004 #3
    There's this famous picture of Neil Armstrong with an American flag on the moon staked to the ground. The flag looks like it is fluttering. I've always wondered: Why is that?
  5. Feb 29, 2004 #4
    "Of course a flag can wave in a vacuum. In the shot of the astronaut and the flag, the astronaut is rotating the pole on which the flag is mounted, trying to get it to stay up. The flag is mounted on one side on the pole, and along the top by another pole that sticks out to the side. In a vacuum or not, when you whip around the vertical pole, the flag will ``wave'', since it is attached at the top. The top will move first, then the cloth will follow along in a wave that moves down. This isn't air that is moving the flag, it's the cloth itself."

  6. Feb 29, 2004 #5


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    Besides, how can you see a flag "fluttering" in a still image? The flag is just crumpled.

    - Warren
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