Suppose you're traveling on a space ship at 9/10 the speed of light (.9c). You have a high-powered rifle that shoots bullets at the same speed. Suppose you shoot the bullet perpendicular to your direction of travel.

It appears that the bullet would travel at a 45-degree angle (northeast, if the ship is traveling north and the bullet is shot eastward), at about 1.2728c which is faster than light. Why is this wrong, and what would the actual speed and direction be?

Too bad I didn't pay much attention to that semester of Physics where relativity was taught, because optics (which was taught first in the same semester) completely screwed me up.

I think that it has to do with inertial frames of references (time dilation and length contraction). I'm not sure but I think that it has to be dealt with by using Lorentz transformations. Someone who knows more about relativity may want to give it a shot.

Posted by np_rt on 2005-01-18 01:03:13