解答几道英文版的关于时空、相对论的物理题,英语及物理界的高手来,

解答几道英文版的关于时空、相对论的物理题,英语及物理界的高手来,
1.Can you travel while remaining in one place in space?Explain.
2.Does light travel through space?Through time?Through both space and time?
3.What does it mean to say that motion is relative?
4.The speed of a ball you catch that is thrown from a moving truck depends on the speed and direction of the truck.Does the speed of light caught from a moving source similarly depend on the speed and direction of the source?Explain.
5.What does it mean to say that the speed of light is a constant?
6.The ratio of velocity gain to time for a freely falling body is g.Similarly,what is the ratio of distance to time for light waves?