That's a nice question.
So where did the 8 min go? The times between the arrivals of each blip are slightly stretched, because each blip has a little farther to travel. But you might say that if it's going slowly enough (low v) that's hardly any stretch. Yes, but the slower it goes the more blips there are before it arrives. So it ends up being an 8-min delay.
What about the relativistic time effect? Why doesn't that argument keep it important even for slow trips? The reason is that the relativistic effect is proportional to (v/c)
2, to lowest order, so even though the trip time goes as 1/v, the net effect goes as v.
The effect that you've asked about is really just the Doppler effect, and to lowest order it goes as v/c. Since the trip time goes as 1/v, it remains even as v gets small.
Mike W.
(published on 03/02/2013)
