Invariance of velocity ?

1. Dec 28, 2012

jk22

does SR change the direction of light and if yes is it then possible to find a transformation keeping the velocity of light invariant and not only its speed ?

2. Dec 28, 2012

Staff: Mentor

I think just the identity transformation.

3. Dec 28, 2012

Staff: Mentor

Any Lorentz boost will leave invariant the direction of light beams that are directed along the same axis; but it will change the direction of light beams that are not directed along the same axis. So a Lorentz boost along the x axis would not change the direction of light beams traveling along the x axis; but it would change the direction of all other light beams.

Also, even light beams whose directions are not changed by a Lorentz boost will have their frequency changed.