• Question: How do using very powerful lasers cause objects to travel faster than the speed of light?

    Asked by marsi003 to Mike, Pip, Tianfu, Tim, Tom on 29 Jun 2012.
    • Photo: Tim Stephens

      Tim Stephens answered on 29 Jun 2012:

      They don’t. Nothing can travel faster than light.

    • Photo: Tom Lister

      Tom Lister answered on 30 Jun 2012:

      Information can travel faster than light. So you can fire a laser at one end of a piece of material and a signal will reach the other end faster then light travels. This is because the information spreads out at the same time at travelling through (so one end gets there early, but it takes longer for the entire light packet to get there). This is probably the experiment you have heard of – it got me confused too so I emailed the guy who did it and that is what he told me (as I remember).

      According to relativity, things that travel faster than light are called tachyons, although they are currently considered theoretical.

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