Time Dilation - Albert Einstein and the Theory of Relativity

@PhanatixDDH Instead of light just consider bullet, I think the bullet will go in the straight direction.

I think I understand now. The light can't really be compared to a bullet, because light moves freely through space and always has a constant velocity. However, light does have mass, and thus also has inertia, and will hit the other ship.

@PhanatixDDH I think also the same, but i can not understand if electromagnetic wave can also have inertia.

Without a college course, this seems impossible to understand....

BSED thid is what Maam Leop trying to explain.. Watch this & you'll understand..

I thought this was length contraction, and time dialtion was passing time faster while in motion.

time dilation does not need gravity.. as the video shows

The system moving are both ships including the light. Another way of looking at it, is saying the system with both ships is still and the planets, space or what ever is passing by in opposite direction at (nearly) speed of light.
Hence the light will strike the other ship and the light IS moving in a straight line.