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WHY EARTH SPINS?

 

  •         Earth is rotating on its axis about 1673 km/h.
  •         Why do earth spin? is an age old question. Not only earth , everything in the universe spin.
  •         And the common answer for such questions is inertia – the ability to resist change in motion.
  •         But now, let's think deep into it.
  •        To answer this we have to go to the beginning, about 4.5billion years ago.
  •         In our old blog Nebula, we saw how the stars are formed.
  •         4.5 billion years ago our solar system was formed from a nebula.
  •          In that nebula as usual when hydrogen and helium atoms contracted and expanded, the nebula stated to rotate with an angular momentum. As the process goes on also, the direction of spin didn’t change.
  •         After sometimes sun, planets, asteroids are formed out of the nebula.
  •         To conserve the angular momentum, all the objects formed from the nebula had spin.
  •         The angular momentum of the plants are not constant, it is decreasing.  After some millions of years, one day will have less than 24 hours.
  •         Almost all the planets spin in anticlockwise direction, but Venus is an exemption.
  •         Venus spin in clockwise direction. It may be because some object may hit it and its spin axis direction may changed. Or its spin angular momentum would have became zero and started to spin in opposite direction.
  •        Uranus also have clockwise spin, because it was knocked on its side.

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