What Max,

The cow has a good point, but it is complex and I can't explain it well.
It has been discussed fairly extensively in recent threads. I suggest that
you search for threads in the last year which discuss "relativistic mass".
The executive summary is that the idea of relativistic mass is misleading
at best and incorrect at worst, so use of the term "rest mass" is preferred
to distinguish it from the relativistic effect. The Lorentz transforms are
correct, but inadequate to describe effects involving gravity and mass.

If I recall correctly, Ken G and publius were principals in the discussion.

-- Jeff, in Minneapolis

__________________
http://www.FreeMars.org/jeff/

"I find astronomy very interesting, but I wouldn't if I thought we
were just going to sit here and look." -- "Van Rijn"

"The other planets? Well, they just happen to be there, but the
point of rockets is to explore them!" -- Kai Yeves