Hi, I've just got the following question for you guys... Say that Bob is travelling away from the Earth at 0.9999c in a glass spaceship. Phil, who is on Earth and can see Bob’s spaceship, notices that Bob’s clock is running slow. That makes sense. HOWEVER, since there is no ideal frame of reference and no frame is better than another, could one not equally argue that Bob is the one who’s stationary and that Phil (and the earth) is moving away from Bob at 0.9999c. Bob would therefore observe that Phil’s clock is running slow, right? So, who’s going to age more, Bob or Phil?? Also, let’s consider the twin paradox. A stays on Earth (‘stationary’), B leaves at 0.9999c and returns to find that A is much older. Could one also not argue the converse – that B is stationary and that the earth (with A on it) leaves at 0.9999c and returns, leaving A (and everyone on earth) younger than B. How does one reconcile this apparent contradiction?