• Question: What causes thunder?

    Asked by meg123 to Amy, Karen, Sarah, Vijay, Will on 18 Jun 2012. This question was also asked by karina123.
    • Photo: Karen Reed

      Karen Reed answered on 18 Jun 2012:

      Hiya Meg,

      Thunger is the loud sound that occurs when air molecules get ripped apart during a lightling strike. So what causes a lightning strike?
      Well it starts in the clouds. they contain charged particles – these move around in the cloud and will naturally seperate out with the more positive ones at the top and the negative ones at the bottom of the cloud. If the difference in the charge between the bottom of the cloud and the earth (or things on the earth) is big enough, then the electrons want to flow between the cloud and the earth. when they do you see the lightning bolt (electricity) flow between the cloud and the earth – this is the lightning.
      The lightning literally rips the air apart, and that causes massive vibrations which is what we hear as thunder.
      so lightning always come 1st as light travels faster than sound. The gap between the light and the bang gives you an indication as to how far away the lightnight strike was.
      Hope that helps

      Oh and I should say you can sometimes get lightling traveling between clouds.

    • Photo: Sarah Martin

      Sarah Martin answered on 18 Jun 2012:

      Hi meg123 and Karen! I couldn’t explain that any better. I love thunderstorms!
      You can actually find out how far a lightning bolt hit by counting the seconds afterwards (one-elephant-two-elephants-three-elephants) until you hear the thunder.
      Light (which is an electromagnetic wave) travels at 300 million kilometres per second, but sound (which involves pushing molecules forwards and backwards) is much slower and only does 340 metres per second (so one kilometre every three seconds). So you’ll see lightning that strikes 3 kilometres away almost instantly – but you won’t hear it until 9 seconds later!

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