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Distortions in time |
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Imagine a vehicle with two parallel mirrors. A pulse of light is directed at one, and it then proceeds to bounce between them. The light crosses the distance at the speed of light of course, and the time taken is the distance divided by the speed of light. Now imagine that the vehicle is moving – to an observer outside of the vehicle, it seems that the light is travelling not only the distance between the mirrors, but also the distance moved by the vehicle in the time it takes to get between the mirrors. But it is still doing this at precisely the speed of light – so to the observer outside sees the light taking a longer time to travel between the mirrors than the observer on the vehicle. To the outside observer time appears to be moving slower in the vehicle. However because all movement is relative, the observer on the outside also appears to be experiencing time slower compared to the observer in the vehicle. Where does this get out experienced time traveller then? Well, if you are going on a long journey, not only will going faster get you there quicker, it will make the time you experienced be reduced too. If there aren’t any exciting parties coming up for a few years, then a short round trip at near light speed will take 5 minutes to you, yet arrive fashionably late for the party of the century. [http://www.phys.unsw.edu.au/einsteinlight/] |
