• Question: how do lasers travel through a) air? and b) water?

    Asked by confuddled213 to Mike, Pip, Tianfu, Tim, Tom on 27 Jun 2012.
    • Photo: Tom Lister

      Tom Lister answered on 27 Jun 2012:

      Air doesn’t have a lot of stuff in it, there is a lot of ‘space’ – so the light travels along and doesn’t really collide with many things. So the light from a laser can travel a long way through air.

      Water has less space, but the molecules in water don’t absorb visible light very well. So, although lots of the light will be scattered off these molecules, it can still travel quite well through water.

    • Photo: Tim Stephens

      Tim Stephens answered on 27 Jun 2012:

      Light is an electromagnetic wave, which is a kind of transfer of energy. Light (and therefore lasers) travel through water and air in the same way, which is as vibrations of an electromagnetic field.

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