Time travel and you
This doesn't make all time travel impossible. I do believe in time travel. Time travel to the future. Time flows like a river and it seems as if each of us is carried relentlessly along by time's current. But time is like a river in another way. It flows at diff erent speeds in diff erent places and that is the key to travelling into the future. This idea was first proposed by Albert Einstein over 100 years ago. He realised that there should be places where time slows down, and others where time speeds up. He was absolutely right. And the proof is right above our heads. Up in space.
This is the Global Positioning System, or GPS. A network of satellites is in orbit around Earth. The satellites make satellite navigation possible. But they also reveal that time runs faster in space than it does down on Earth. Inside each spacecraft is a very precise clock. But despite being so accurate, they all gain around a third of a billionth of a second every day. The system has to correct for the drift, otherwise that tiny di fference would upset the whole system, causing every GPS device on Earth to go out by about six miles a day. You can just imagine the mayhem that that would cause.
The problem doesn't lie with the clocks. They run fast because time itself runs faster in space than it does down below. And the reason for this extraordinary e ffect is the mass of the Earth. Einstein realised that matter drags on time and slows it down like the slow part of a river. The heavier the object, the more it drags on time. And this startling reality is what opens the door to the possibility of time travel to the future.
Seriously, my brain hurts. I get it on one level. That is, time passes in relative measures at great speed. I do not, however, understand how matter drags on time here on Earth. Does mass increase the effect? Would a supersized Earth have an even larger time differential than space? This guy is making my week. First he tells us that he's certain extra terrestrials exist and now he believes in time travel. Awesome. The paradoxical nature of the whole thing is puzzling. Hell, I had trouble figuring out that movie "Primer" let alone this relative time travel speed thing.