Hi I'm new to the forum, I am 15 years old and currently taking my GCSEs. I have asked my physics teacher several questions which he has not answered so I was wondering if you would be willing to take the time to give me some answers. Firstly, lets use the twins A and B and suppose twin A travelled in a spaceship that was going at a speed whereby 1 year passed on that spaceship would mean 5 years passed on Earth.Twin B stays on Earth. Lets suppose that they had TVs on which they could watch the other twin. If twin A watched a movie which lasted 2 hours would it appear to be a 10 hour film if Twin B was watching Twin A watch it? If twin B watched a movie lasting 2 hours would it seem only 24 minutes in length to twin A, assuming he was watching Twin B watch it? Does going at the speed of light actually increase the length of life that a human could experience? Assuming the previous conditions, although it would appear to twin B that twin A would have lived for 50 years but only aged 10, would twin A only have experienced 10 years? Does this mean that if everyone started being accelerated at near the speed of light, nobody would really recognise it because we would have nothing else to compare it to? What would be the uses of being able to move at near the speed of light? The only one that I could think of would be someone who was curious about the future of the human race being able to slow down their time compared to the Earths to be able to see further into the future. If we were to move at the speed of light(I recognise it's impossible but for the sake of this question assume it's possible) would we have to eat, drink, sleep etc? I'm wondering about this because I'm assuming our biological clocks would stop completely. I apologise if these seem very simple questions but I would greatly appreciate any answers to these questions that have been puzzling me for some time.