Have we ever sent a probe into a black hole? originally appeared on Quora, the place to gain and share knowledge, empowering people to learn from others and better understand the world. You can follow Quora on Twitter, Facebook, and Google Plus.
Imagine a group of early humans, say, somewhere in Europe, who just discovered the world’s first raft. They managed to get across a small river, without getting their feet wet! A tremendous accomplishment.
But then, as they get home, one of their fellow tribesmen asks: have you already sent a ship to discover America?
Incidentally, sending a sailing ship to America is technologically far closer to that primitive raft than sending a probe into a black hole would be compared to our present level of technological development.
Our most distant space probe to date, Voyager 1, is about 140 times as far from the Sun as the Earth is. It took more than 40 years for the probe to travel this far.
The nearest black hole candidate is roughly 1.3 million times as far away as Voyager 1. The probe would have to travel more than 50 million years (a lot more, actually, as it is still slowing down due to the Sun’s gravity; it hasn’t quite left our neighborhood yet) to get there.
And what would it do when it gets there? Suppose it is aiming for the black hole. As it approaches that black hole, tidal forces increase, up to the point where they would simply rip the probe into shreds. In the case of a small (stellar size) black hole this happens before the object reaches the event horizon.
But suppose it does reach the event horizon. What then? You have to keep in mind that the event horizon, from the perspective of us living outside of it, is forever in the future. So the moment when the probe actually reaches the horizon is in the infinite future for us (this is the extreme relativity of black holes.) For the probe to return, or to send a signal back to us, it would have to master time, as it would need to either travel backwards in time or send a signal backwards in time. To the best of our knowledge at present, neither of these will ever be possible.
So you see… our raft-building ancestors were closer, much closer to discovering America than we are to sending a probe, never mind into, simply to the vicinity of a black hole. The one thing they didn’t have was science-fiction movies and television series that make space travel appear easy and space, well, small. Space is not small. Space is incredibly, incredibly vast, and the distances are simply not comparable to any human experience.
Photo Credit: GM Stock Films/Getty Images