Heres another good one for you:
Galaxies travel through space, away from each other, and most galaxies travel at very high speeds. If time slows down to the traveler, or galaxy as it approaches the speed of light, and our galaxy is moving many times faster than another galaxy, would our galaxy be younger, given they were both formed at the same time? Would two people born at the same time, one was born here on earth and one born on a planet in a slower moving galaxy actually be different ages? and how would one determine what the "same time" is here in relation to another galaxy?