• Question: How fast is the speed of light?

    Asked by MiniEinstien to Francesca, Laura, Matthew, Andrew, Rebecca on 10 Nov 2014.
    • Photo: Matthew Camilleri

      Matthew Camilleri answered on 10 Nov 2014:

      The speed of light is 299 792 458 m / s, which is pretty fast indeed.

    • Photo: Francesca Palombo

      Francesca Palombo answered on 10 Nov 2014:

      Approximately 300 000 000 m/s in vacuum

    • Photo: Laura Schofield

      Laura Schofield answered on 10 Nov 2014:

      Matthew and Francesca have already answered your question, but I wanted to say I really like your name! I hope your hair is slightly more under control than Einstein’s though!

    • Photo: Andrew McKinley

      Andrew McKinley answered on 10 Nov 2014:

      I see the question has already been answered, so I’ll extend it with something else… and related to your screen name:

      If someone throws a ball at you at a speed of 10 metres per second and you run towards it at 4 metres per second, you will feel the ball hit your hand at 10+4 = 14 metres per second. (Ok, I’m simplifying; assume the ball is travelling perfectly horizontally)

      If someone throws a ball at you at a speed of 10 metres per second and you run backwards at 2 metres per second to catch it, you will feel the ball hit your hand at 10-2 = 8 metres per second.

      OK, so what? Well, the speed of light is *absolutely the same* regardless of whether you are travelling towards the light, or away from the light. Even if you are travelling at 200,000,000 metres per second towards the light (very very fast indeed!) the light will still hit you at 299,792,458 metres per second.

      This is the crucial factor in Einstein’s theory of Special Relativity; the fact that light travels at a constant speed *no matter what speed you move at* means that you can, effectively, travel into the future by moving very very fast!

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