A while back I saw a TV documentary on the Discovery Channel about space and Einstein’s theory of relativity, in particular special relativity. This is fascinating stuff, most of which is way beyond what I am able to wrap my head around, however. One of the things that comes from special relativity is that the time of a rapidly moving object seems to slow down. This is also something that makes my head hurt if I think about it too much. To summarize, it means that if you jump on a spaceship that travels with a speed close to the speed of light, time will move much slower for you relative to the people who is still stuck on Earth.
This is called time dilation and sounds like science fiction and theoretical mumbo jumbo, but it’s actually possible to prove in everyday life. The clocks on board the GPS satellites orbiting Earth are intentionally set wrong to compensate for time dilation. If they were not, GPS simply wouldn’t be as precise as it is. It’s also possible to see this if you get two very accurate, synchronized clocks, go to an airport, leave one of the clocks there and fly around the world. When you get back, you’ll notice that the clock you brought with you on the journey has actually slowed down a bit relative to the one you left on the airport. You’re probably also fed up with airline food.
Pretty funky stuff right there. I’m venturing a bit outside my normal domain here, so the clock-on-an-airplane story might not be entirely accurate, but I’m pretty sure I’ve heard it somewhere before. Please correct me if I’m wrong. Continue reading "Three Weeks." →
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