Edit: Sorry, the title should say LIGHT, not time! << Mentor Note -- Title updated >> Let's say you're on a train, in the back of a car. The train is stationary. You shine a laser to the front of the car, and you can measure the time it takes for the laser to reach the wall. Now, if the train starts moving forward, since the speed of light is the same no matter the reference, if you perform the same experiment, will the light take longer to hit the wall because the wall has "moved" away from the source during the time it took for the light to get there? If yes, is the travel time of light a function of the speed of the train? Thanks in advance!