This Physicist Says He's Just Found the Secret to Time Traveling to the Future
When scientists start talking about time travel, the conversation always seems to come back to three things: the speed of light, wormholes, and Einstein.
Time travel into the past is usually considered to be off the table—aside from the physics of getting there, it starts to do wacky things like violate causality—but time travel to the future is theoretically possible, according to Carlo Rovelli, a theoretical physicist at the Centre de Physique Theorique de Luminy in France. All you need is money—and lots of it.
"If we had enough money we would build a starship, in principle it is not very hard. You go very fast away or you go near a black hole. You come back and you have traveled into the future. If you want to go into the next century, into the next millennium then it's easy; you just get enough money, go near a black hole, wait a little bit, come back and you are as much as you want in the future."
It seems like Rovelli is creating some kind of scheme to sucker millionaires into developing lightspeed-capable starships and then stranding them in space, but what he's saying is actually a simplified version of what Einstein (and scientists like Brian Greene) has been saying for years: mass warps space and time, and so does speed.
According to Einstein's theory of special relativity, traveling faster causes time to go "slower" from the perspective an outside observer, while sitting near something with huge amounts of mass (like a black hole) can "slow down" time for those close to it.
In essence, the passage of time is localized to where you are, and if you're in a sufficiently "slow" part of the universe, then waiting a few years in your area may end up being a few centuries in another area.
If that blows your mind, consider this: The clocks aboard GPS satellites are constantly falling behind those on Earth because the planet's mass warps spacetime less the farther you are from it. Essentially, this means the higher you are above the Earth (or another massive body), the more your flow of time will differ from those on the ground. This is what Rovelli means when he jokes, "Your head lives longer than your feet."
So there you go—to see the wondrous world of tomorrow, just hang out over a black hole or hit an appreciable fraction of the speed of light. Easy.