• Question: What makes the world go round?

    Asked by 11sofdel to James, Marcus, Martin, Rob, Suzanne on 16 Mar 2012.
    • Photo: Martin Zaltz Austwick

      Martin Zaltz Austwick answered on 15 Mar 2012:

      Love?

    • Photo: Marcus Gallagher-Jones

      Marcus Gallagher-Jones answered on 16 Mar 2012:

      It’s a wonderful counterbalance between the pull of the suns gravity causing the earth to accelerate in one direction and pull it towards it at the same time. This is known as centripetal force.
      http://en.wikipedia.org/wiki/Centripetal_force
      The earths rotation on it’s axis is actually a remnant of it’s formation from dust clouds coming together billions of years ago. I on’t understand it much more than that though sorry.

    • Photo: Suzanne McEndoo

      Suzanne McEndoo answered on 16 Mar 2012:

      Conservation of angular momentum!

      There are certain things that have conservation laws, which mean that they can’t be created or destroyed. So conservation of energy tells us that (in a closed system, which means that everything is included, and there are, say, no particles leaving or entering the system) the total energy has to stay the same all the time. How it’s shared amongst the parts of the system can change, but the sum of the energy has to stay constant.

      We have the same idea of angular momentum, which is about rotation. It means that the earth can’t just stop rotating or start turning the other way without something coming along and taking away it’s rotation.

      So our solar system was formed by a biiiiig rotating cloud that cooled and solidified. Because of the angular momentum though, all the parts of the solar system still have that rotation. This is why the planets are still rotating billions of years later.

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