If astronauts could travel at v = 0.930c, we on earth would say it takes (4.20/0.930) = 4.52 years to reach alpha centauri, 4.20 light-years away. the astronauts disagree. (a) how much time passes on the astronauts' clocks? (b) what is the distance to alpha centauri as measured by the astronauts?
