suppose two rockets with a passenger are nearing speed of light velocities and are going opposite directions. Relative to eachother one rocket will seem stationary while the other rocket will look like it’s going almost twice the speed of light. What do both passengers see?

Question

I can’t wrap my head around it. But maybe it might be a very silly question with a simple answer.

In: Physics

Answer 1

Your assumptions are wrong. The occupants of each rocket will not see the other moving “almost twice the speed of light.” Each will see the other moving close to but not up to *c* since nothing in either’s reference frame can exceed it. Someone else has already given the equation for the exact relative observed speed

This is neglecting the effect on light itself of each’s perceptions. Those will be severely messed up in ways that depend on the rockets’ orientation to each other