Is it possible?

Discussion in 'Earth Science' started by ananisikerim, Jul 3, 2004.

  1. ananisikerim Registered Member

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    Has this ever happened in earth history, or can it ever happen? Can the sun ever rise from west? What i mean is can the world start to turn the opposite direction and let the sun rise from west? Is it possible?
     
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  3. Andre Registered Senior Member

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    Yes, it is possible. It happened to Venus too. But you'd have to wait a couple of billion years.
     
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  5. Alpha «Visitor» Registered Senior Member

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    The earth's axis would have to spin ~180 degrees.
    Or reverse direction in orbit, but we know that's not gonna happen.
     
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  7. everneo Re-searcher Registered Senior Member

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    Still the sun will rise from east, in both the cases.

    The earth has to reverse its direction of rotation about its own axis.
     
  8. Alpha «Visitor» Registered Senior Member

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    No, my first statement was correct. If the axis of rotation were to rotate 180 degrees in a plane perpendicular to the direction of the sun, it would rise on the opposite side.
     
  9. Andre Registered Senior Member

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    I insist.

    This could happen to Earth too.

    The moon recedes with some inch or so a year, whilst the Earth is slowing down. Both cause the frequency the precession of the equinoxes to decrease (now 26,000 years). As soon as this frequency approaches the frequency of the obliquity cycle (now 41,000 years) resonance will occur, causing extreme shifts in obliquity, known as the chaotic zone

    Correia and Laskar have calculated the possible spinning history of Venus and theorize that either the spin axis of Venus toppled causing the retrograde spin or the differential gravity interaction of the dense atmosphere with the sun caused it.

    http://astro.oal.ul.pt/~acorreia/cvpubs/venus1.pdf
     
  10. Alpha «Visitor» Registered Senior Member

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    No one said otherwise.
     
  11. everneo Re-searcher Registered Senior Member

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    Alpha,
    In both positions, for example, America comes after Africa to see the Sun on horizon. The hands of a watch always run clock-wise (1 before 2 before 3..) even if you keep the the watch face down.
     
  12. DwayneD.L.Rabon Registered Senior Member

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    locked
     
    Last edited: Oct 28, 2005
  13. Alpha «Visitor» Registered Senior Member

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    Er, my mistake.
    I suppose it would have to spin in the opposite direction after all.
     
  14. the_greenvision (3,746,185 posts) Registered Senior Member

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    Is it possible for a really major asteroid - or a nasty comet - strike to reverse the spin of a planet? Now. Let's imagine Shoemaker-Levy II smashing right against the equatorial spin of Earth... Whoa

    Please Register or Log in to view the hidden image!

     
  15. Alpha «Visitor» Registered Senior Member

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    I think so, though I don't believe any life on earth would survive an impact of the necessary magnitude.
     
  16. Andre Registered Senior Member

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    If I may have a different opinion, I'm afraid there are a few complications. If you drop a mouse from ten feet hight, it just runs away. If you drop an elephant of ten feet, it will break it's legs and a lot more. It probably dies on the spot.

    Earth is a tremendous elephant in that respect. It's not a game of marbles (mice). If you hit one side of the Earth with an asteroid, big enough to change the spinning speed, that side will start decellerating. However due to it's size, the shock wave will take ninety minutes before it reaches the opposite site of the world. So, since that part just continues spinning fat dumb and happy while the opposite side stopped, the result is an Earth torn to pieces. All what's left is another asteroid belt.
     
  17. ck27 Registered Senior Member

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    Yes i agree a asteroid big enough to change earths rotation would be powerful enough to shatter this planet into nothing but pieces. And walla another asteroid belt or gravity pulls the planet back together and walla a lifeless dead planet like all the others.
     
  18. buffys Registered Loser Registered Senior Member

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    yep, the earths mass is something like 6.0 x 1024kg and spins 1670 km/hr (at the equator). I haven't done the math but based on those numbers I'm pretty sure it would take a world shattering event to even slow it down let alone reverse the spin.
     
  19. Alpha «Visitor» Registered Senior Member

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    I feared as much. I was sure life wouldn't survive, but not sure if the planet would or not.
     
  20. vslayer Registered Senior Member

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    it can rise from the west but not the other side.

    just wait for the next flip of earth poles, as far as compasses are concerned north will be south and east will be west
     
  21. buffys Registered Loser Registered Senior Member

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    that's cheating though, you'd still be looking the same direction at sunset and sunrise. Only the names of the directions you were looking would have changed.

    As far as actually changing the earth's spin, the more I think about it, the more disasterous I think it would be. If you could reverse the spin (by some unknown method that wouldn't destroy the planet) what about the oceans, the molten core and the atmosphere, wouldn't they keep spinning the wrong way for a while? I can't imagine what the result would be but I'm pretty sure it would be very, very bad. Tidal waves, earth scouring wind speeds and volcanoes popping their lids across the planet at the very least.
     
  22. The Singularity The last thing you'll ever see Registered Senior Member

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    The atmosphere and the ocean circulation are both heavily tied into the rotation of the planet. If Earth were to reverse it's rotational spin ... then the atmosphere and the ocean circulation would dramatically alter into a new pattern.

    The elements of the atmosphere (such as the Trade Winds and weather patterns) would eventually reverse direction along with the new rotational spin of the planet (since momentum would keep it going "the wrong way" for a bit). In essence, any atmospheric patterns we see today would only reverse direction in the new spin of the planet. This picture shows what the major large-scale wind systems of the planet are now:

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    To imagine what would happen to those patterns if the planet would reverse its spin, just reverse the direction of those arrows (left to right and right to left). The curvature of the winds is due to the Coriolis force

    However, the ocean circulation wouldn't be so compelled to reverse direction as easily. Any reversal in the spin of the planet would completely collapse the ocean current circulation and eventually form a new pattern which could completely alter climate conditions all over the planet. For example, Canada and Europe would no longer get it's warm water from the Gulf.

    Even though both are basically the same system ... it's the oceans which practically controls atmospheric phenomenas such as the weather.
     
    Last edited: Jul 4, 2004
  23. buffys Registered Loser Registered Senior Member

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    eventually I'm sure they would settle into a new pattern (though I suspect it'd be more complex than a simple reversal of those arrows) but before everything was settled there would be serious problems.

    The atmosphere would suddenly be moving over the planet at atleast twice normal speed. Suddenly the continents would find themselves litterally burying themselves into oceans that haven't yet realised they're going in the wrong direction. And since the crust is floating on a spinning liquid core, if the crust just started moving against that internal spin it would... well I have no idea what it would do but I imagine it would mean earthquakes and volcanoes of hitherto unknown magnitudes.
     

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