I’m working on the (new) Sekrit Projekt here, and I’ve realized I need some info I don’t have in my brain and am not successfully Googling up.
Is there a set of (simplified) equations that can be used to establish the differential between ship-time and observer-time for a relativistic transit at interstellar distances? I’d love a calculator applet or spreadsheet that would let me set distance in lightyears and ship speed as a fraction of c, thereby showing the two separate values for elapsed time. (And I know that this stupid-simple example ignores acceleration/deceleration time, but you get the idea.)
Or am I asking too much here? Comments, Web links, Excel files and whatnot welcome.