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World Jump Day

  1. Dec 1, 2005 #1
    I would really like to know if this is really true.

    Please also read by the [more info]
     
  2. jcsd
  3. Dec 1, 2005 #2

    Pengwuino

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    no

    tomatooooo
     
  4. Dec 1, 2005 #3

    Mk

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    Wow that's one of the craziest things I've ever seen.

    Even if everybody in the world jumped up and down at the same time the orbit wouldn't change.
     
  5. Dec 1, 2005 #4

    russ_watters

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    Conservation of energy says nothing at all happens to the earth's orbit when you jump.
     
  6. Dec 1, 2005 #5

    DaveC426913

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    Of course nothing would change in the larger sense.

    But it would be interesting to see if it showed up on seismic readings...
     
  7. Dec 1, 2005 #6
    Thats crazy. These people can't be serious.
     
  8. Dec 6, 2005 #7
    Well I predict that if you react you will get an e-mail on 31 March stating that tomorrow is world jumping day.

    That would be great.
     
  9. Dec 6, 2005 #8

    Pengwuino

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    :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl: :rofl:

    http://www.museumofhoaxes.com/tacobell.html

    The Ford Lincoln Mercury Memorial
     
  10. Jan 13, 2006 #9
    Simple Conservation of Energy

    Conservation of energy is the only issue here. Observing the earth (and all of its inhabitants and atmoshphere) as one mass, the only way to change the orbit is if it is acted upon by an outside force. So either external gravity/impact/force could change the orbit, or the Earth mass would change by expelling matter. If all of these people would jump off into space, never to return, then that would change the orbit minutely. If so many people believe this, perhaps that's the best option... :rolleyes:
     
  11. Jan 13, 2006 #10
    Okay... bare with me. When there is a massive earthquake (such as the tsunami in December of '04) It can alter the Earth's orbit slightly... so why not everyone jumping up and down at exactly the same time? You really think that would cause NO rumbling at all? 6.5 billion people is a lot of weight. This gets me to questioning "what exactly an earthquake is and how it is caused?"... and why it can change the orbit of the Earth. Someone talk with me :)
     
  12. Jan 13, 2006 #11

    russ_watters

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    You misread/hear: earthquakes alter the earth's rotation, not it's orbit.
     
  13. Jan 13, 2006 #12

    russ_watters

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    Yeah, but that would be the end of basketball as we know it.... :biggrin:
     
  14. Jan 13, 2006 #13

    matthyaouw

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    An Earthquake is the sudden release of pressure along a crack known as a fault. Movement along these faults is not steady due to frictional force. When stress builds up enough, it will overcome friction and a section of rock will slide over another up to a few metres in distance. This releases massive shockwaves which causes shaking at the surface.
     
  15. Jan 13, 2006 #14
    Rotation changed, not the orbit. WORLD SUCK/BLOW DAY

    Russ is right, the rotation of the Earth is affected by these quakes. We can control the rotation of the earth, but not the orbital path, because the Earth mass as a whole is still traveling in the same path even though the rotational path changes.

    WORLD SUCK/BLOW DAY (This one would actually work.)
    Needed: 2,500,000,000 Registered: 1

    Everyone would face west then SUCK in a huge breath of air.
    Turn east and BLOW it out hard.

    This will slow the earths rotation, extend the length of an Earth day.

    (And according to the World Jump Day experts, bring back Elvis and the Easter Bunny):biggrin:
     
  16. Jan 13, 2006 #15

    Pengwuino

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    I have no doubts that 2.5 billion people on this earth really suck.
     
  17. Jan 13, 2006 #16
    Thanks guys. I guess what I was asking for was a bit deeper, and a bit of a misunderstanding about orbit and rotation. That's funny pengwuino :P
     
  18. Jan 17, 2006 #17
    The situation might be more complex than a simple analysis with conservation of momentum.

    Imagine two containers in free space connected by a spring.
    One consists of viscoelastic tissue like human tissue and the other consists of cold tar, like earth's magma. Which direction would the system shift if it were to oscillate? That's the real question here.
     
  19. Jan 17, 2006 #18

    russ_watters

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    Are you meaning to imply that an oscillation can cause a net displacement of the center of gravity of the system by dampening one side?

    No.
     
  20. Jan 18, 2006 #19
    Yes. I meant to imply that.

    How come it doesn't work?
     
  21. Jan 18, 2006 #20

    russ_watters

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    There is no outside force to move the system.
     
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