"The closer you get to the speed of light, the more space-time folds on itself," Ender said, making a little gesture of his hands to illustrate a reverse mountain, slowly folding in on itself. "Time in and on the moving object is pulled 'tighter', so to speak. When you reach a certain speed, one year within can become ten outside, or more than that. You don't notice the time compression because you're inside the vessel. If you put a ship at a relativistic enough speed, and you kept going, you could be a century ahead and have barely a decade on you."