Could someone explain this to me? Unless my math is wrong, the trip should take ~1.52 x 10^6 years, not 25 years (I'm assuming that the "trip to the edge of the observable universe" is referring to the radius of the universe, which I've read to be 1 500 000 light years), to the one in the spaceship. How is it that time is compressed for her? Also, I've been having trouble finding a good explanation of the Twin Paradox. I know that because the twin in the spaceship has to change directions, he jumps from one frame of reference to another, but I haven't been able to find an explanation of why that means that their observations aren't contradictory. Anyone care to explain this to me, too? Thanks in advance :).