I'm trying to understand the famous train-platform thought experiment ( http://www.bartleby.com/173/9.html ). I understand part of the Theory of Relativity is that the speed of light is the same whether the observer is moving or not.
Does the train-platform thought experiment depend on the fact that the speed of light is the same for the observer in the train and the observer on the platform?
Suppose instead of two lightning bolts hitting the front and back of the train, we had two cannonballs hitting the front and back of the train, and the observers were listening for the sound of their impact.
In the above case we'll be using sound waves instead of light, and the velocity of sound waves can be added to the velocity of the train normally, would that change the results of the thought experiment?