" I'm right in assuming that if we get close to the speed of light then 40 + 40 years would be a round trip?"
Doesn't the theory of relativity have something to say about ageing when travelling at that speed? You would arrive back on earth at a point in time that was not 80 years after you left. IIRC time for a person on Earth would pass more quickly?
Biting the hand that feeds IT
