• Question: what makes the world spin round at the pace it does

    Asked by oufc4ever to Alan, Caspar, Diana, Murray, Sarah on 21 Mar 2011 in Categories: .
    • Photo: Caspar Addyman

      Caspar Addyman answered on 21 Mar 2011:

      I am not entirely sure.. The speed at which it spins on it’s axis is just an accident of the history of our solar system. All the planets formed by matter clumping together out of a disc of dust around the sun. When that is happening, things are orbiting the sun (otherwise they’d fall into it.) and so everything is moving in mostly the same direction.. anything going the wrong way usually gets bumped around.

      Now If you imagine a large blob of stuff bumping into another lump of stuff it is very unlikely that they will stick straight together chances are they bump slightly at an edge and spin around each other as they start to stick together. that is the start of planetary spin.. and once it starts there is nothing in the way to stop it..

    • Photo: Sarah Thomas

      Sarah Thomas answered on 21 Mar 2011:

      This is such a hard question…

      Ok I think it has something to do with the big bang. I think the world spins because of leftover momentum from the reaction that all of the planets and the Sun formed from. Each molecule in the reaction had its own momentum, and as they came together, their momentums added up, and needed to be conserved. This created a sort of reactive cloud and each of the planets was formed inside the cloud as all the solid particles clustered together from gravity. Over time they accumulated more and more material. And once again, the rotation of the planet was caused by the addition of all the momentum of the particles that came together. This is why all of the planets (except Venus) rotate in the same direction.

      I don’t know why Venus rotates the other way? Maybe there was a collision that made it spin the other way…

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