> I can send him a signal too, right? Yes. Rather than stop accelerating (you weren't in the first place, you were in a free fall orbit in my scenario), you ca

> I can send him a signal too, right? Yes. Rather than stop accelerating (you weren't in the first place, you were in a free fall orbit in my scenario), you can just send a light signal back, which is a lot simpler--and uses a lot less rocket fuel. :-) Suppose you receive your buddy's signal at 12:50:01.250058 and immediately send one back. Your buddy will receive that signal at 12:50:02.5000000 by his clock. No 58 microsecond gain, since his clock didn't gain that time, only yours did. > gained 58 microseconds that I could use to run a computer program for a little longer, as an example Yes. The Interstellar scenario discussed upthread gives a much more extreme example (and in my response I gave a similar scenario but involving speed instead of using the gravity of a supermassive rotating black hole to get the time dilation effect).