Alarm Clock King

- does air travel affect watches and clocks?
and if so in what way? how is it related to relativity?

A The only real effect is the owner turning the watch back or forth because of time difference. Relativity has an effect, but only so small it can't be measured with normal watches. The time dilatation described in the theory of relativity was originally tested and proven with Hafele-Keating Experiment, in which extremely precise caesium-beam atomic clocks were taken to planes. The difference was measured in nano seconds (1/1 000 000 000 of a second). You can read more on the subject here: http://en.wikipedia.org/wiki/Hafele–Keating_experiment

- Did they prove with the use of atomic clocks that it's possible to have space travel?
I remember talking in Biology class a few years ago about this scientific study that put an atomic clock on Earth's ground and one at the top of a very tall building. Apparently over a long time the two clocks became slightly off (milliseconds) because the one at the top of the building had a larger circumfrence to travel than the one on the ground and thus moved faster than the one on the ground to keep up. Then the conversation moved to the possibility that if we were to travel in space for a long time and went ridiculously fast (faster than we can now) we could travel for say twenty earth years but upon returning seem only maybe ten years older than when one left. This isn't exactly "space travel" but along those lines. Can anyone confirm this rant of mine or offer any other info I'm terribly interested...

A There have been several experiments with atomic clocks that prove one important part of Einstein's Theory of Relativity. These theories and experiments led to the "thought experiment" that became known as the Twin Paradox. If you have two people, born as Twins. Send one on a 20 year long journey into space at a high fraction of the speed of light (well over 90%) and the other twin remains at home... When the Twin who made the space journey returns home, he'll have aged only a small fraction of the time his Twin aged at home... Here's a fun way to visualize it, provided by the PBS TV Science show called NOVA: http://www.pbs.org/wgbh/nova/einstein/hotsciencetwin/ If you set the speed at 99.99% and choose Rigel as the destination, the space traveling twin will age 25 years while the one at home would age 1800 years (if he could live that long :)) Have Fun!