HI there- i was trying to explain relativity to some friends at a dinner party last night- that the speed of light in a vacuum is constant and therefore- if you have headlights on your spaceship... either time has to slow down, or length contract so that the speed of the photons emitted still equals c: given that speed = distance/ time.
It is dangerous to ask me (non-physics degree) any physics-related questions at dinner parties... but everybody else knew less than me!
So my question is:
1) is the statement above correct?
2) if true- how can you work out how much time dilates vs how much length contraction you get? couldn't you make the equations match with JUST length contraction without any time dilation? Or do they both happen in equal proportions?