Question

I'm having issues with some spaceship relativity problems. Can you please explain them?

A spaceship flies by Earth at a high speed.

1. An observer on earth notices a flash of light at the front of the spaceship slightly after a flash of light at the back of the spaceship. What does an observer on the spaceship observes? (A: need more info to determine)

2. An observer on earth notices a flash of light at the front of the spaceship simultaneously with a flash of light at the back of the spaceship. What does an observer on the spaceship observes? (A: front flashes earlier)

3. 2. An observer on earth notices a flash of light at the front of the spaceship before a flash of light at the back of the spaceship. What does an observer on the spaceship observes? (A: front flashes earlier)

Answer 1

Ans to part A. Since the observer on the earth is Having relative velocity with respect to shapceship, and he observes two flashes at different times,it is quite possible. But observer inside the Space ship may notice these two events occur simultaneously. Information is not clear, so answer is too unpredictable.

Ans to part B.

Length that light must travel from front face is longer than that from the back face. So time required for front face would be longer too. Hence it must flash first so as toreach the observer by the time the ray from the back reaches him

And to part c

Light is reaching him from front first. It means it has flashed first.