It isn't. Wolfram Alpha apparently doesn't know about the relativistic rocket equation. Try here:
http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.h...
It isn't. Wolfram Alpha apparently doesn't know about the relativistic rocket equation. Try here:
http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.h...