🚀 go-pugleaf

In article <SRCTRAN.92Nov19111841@world.std.com>, srctran@world.std.com (Gregory Aharonian) writes...
>   I just finished reading a science fiction (actually with an Islamic
>setting, a rarity in the field), which had as one of the main points of
>the story that if you built a spaceship and continually accelerated,
>eventually you relativistic mass, for the size of the spaceship, would
>be large enough to cause collapse into a blackhole.

     Thinking in terms of "relativistic mass" can sometimes lead you 
astray; this is a good example of that.

     The energy of a moving mass m is  E = mgc^2, where g is gamma = 
sqrt(1/(1-(v/c)^2)), and m is the rest mass.  This is often interpreted
as E = Mc^2, where M is the "relativistic mass" M = mg.  However, the 
mass of an object is best considered to be it's rest mass m. No matter
what the speed of an object, in it's own rest frame it has mass m
(NOT mg).

     As the other response to this thread points out, if the object is 
not a black hole in it's rest frame, then it isn't one in some other 
frame.

Bob Drucker