• Question: @paul how does light travel at such a speed?

    Asked by to Paul on 11 Mar 2014. This question was also asked by .
    • Photo: Paul Coxon

      Paul Coxon answered on 11 Mar 2014:

      This is quite a tricky question.

      The speed of light in a vacuum is 186,282 miles per second, and in theory nothing can travel faster than it.

      Early scientists were unable to think of light as ‘moving’ – they originally thought it shot out instantaneously from our eyes – a bit like laser beams. But, over time, and with more understanding the measurements of the motion of these wave-like particles of light became more and more precise. Thanks to the work of Einstein on relativity, we now understand light speed to be a theoretical limit which can’t be beaten by anything with mass.

      According to relativity, as an object moves faster, its mass increases, while its length contracts. At the speed of light, such an object has an infinite mass, while its length is 0 — which is theoretically impossible. Light can travel at light speed because it has no mass and no definable size.

      Hope this answers your question, emmet 🙂

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