Not so fast. The enormous distances in space are what's hindring space travel. Propulsion systems cannot overcome the fact that those distances can never be travelled faster than with the speed of light. Funny thing is that when we gaze through a telescope to faraway galaxies, we are already time traveling by nature. We see them as they were millions to billions of years ago. Somehow, observing is key. Interestingly, it's what sort of separates Einstein's Relativity Theory (“to observe = to measure”) and Quantum physics (“to observe or not to observe”). What Spielberg does, is put the = sign between observing and visiting… which is kinda neat for a film director.