Re: BOOKS: Pournelle's *A Step Farther Out*

Anders Sandberg (
17 Feb 1999 14:35:58 +0100

Jonathan Reeves <> writes:

> The energy needed to accelerate it from it's _starting_ point increases,
> but not the energy it needs to accelerate itself.
> An object/vessel which is capable of generating it's own thrust will not
> need to output more power to maintain a constant acceleration the
> further it gets from it's origin.

True. But an observer sitting at the origin will not see it pass c, and neither will any other observer moving in an intertial frame with a relative velocity to the origin less than c. A spaceship accelerating at constant acceleration (as measured by the crew) will describe a hyperbolic path in a Loretnz diagram; it will never break c.

Anders Sandberg                                      Towards Ascension!                  
GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y