I think I finally have a decent understanding of time dilation and simultaneity after researching them and watching countless videos about them. But I'm still confused about why length contractions happen. It seems that they can be explained by simultaneity, but I still don't see how. Can anyone explain this to me? Also, lets say that I have a spaceship traveling to the sun at a speed close to the speed of light relative to the earth. As the spaceship passes the earth, the people in the ship see the earth as half its size at rest, and the people on earth see the ship at half its size at rest. How do both frames of reference view the distance left to travel between the ship and the sun? Is it also halved for the people in the ship? Do they get there faster because of it?