NASA Scientist Reveals What Terrifies Him Most About Black Holes

Black holes have been some of the most mysterious phenomena in the universe ever since the first one, Cygnus X-1, was detected in 1964.

Last week, NASA celebrated the cosmic monsters with "Black Hole Week," in which the agency released a new animation of their reality-bending effects.

In a Q&A, Jeremy Schnittman, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, told Newsweek about some of the remaining mysteries of black holes, and what makes them so tantalizing for scientists. Parts have been slightly edited for clarity.

Where do we think most black holes come from?

"We think most black holes are formed in a supernova, when you have a very massive star that reaches the end of its lifetime when it runs out of fuel. All that it has left is gravity, and not enough energy to keep it hot and hold it from collapsing. The gravity wins out, you blow out some of the outer parts—that's what makes the supernova—and then the rest collapses down to a black hole.

"And then there's the other type, basically the other flavor of black hole, which is called the supermassive black hole. And these are the ones that are millions or even billions of times the size of the sun. And we don't really know where they came from. They fit in the middle of the galaxy, we have one in the Milky Way called Sagittarius A*.

"In terms of black holes' lifespan, any sort of black hole like that is basically going to live forever; trillions and trillions of years longer than we expect anything else in the universe to survive."

And they eventually die when they release all their energy as Hawking radiation, right?

"It seems like a very solid prediction. But Hawking radiation is a very, very weak form of radiation and never been actually detected. And of course, there is other stuff in the universe, right? There's this whole cosmic background radiation. So if you think about it, the black hole is never even going to start shrinking until it starts giving off more Hawking radiation than it's pulling in from other background radiation. So you really would need to take a perfect black hole and put it in a perfect vacuum with nothing else before the Hawking radiation would even have a chance at doing anything."

What don't we know about black holes?

"A lot. It's a good field to be in because there's a lot of things that we don't know. So as a scientist, it's great.

"Famous question: if you throw an Encyclopedia Britannica into a black hole, where does all that information go? Does it just get stuck in there forever? Is that ever possible to reproduce by figuring out exactly what way it comes out? I think the jury's still out on that one. There are reasonable arguments to both. One is that it just gets totally jumbled up. And all of the radiation that eventually comes out is just kind of noise. The other idea is that every single photon that comes back out has, encoded in it, some of the information that went in. Either way, it's a highly idealized theoretical situation that would be very difficult to measure in practice."

"One of the things I mentioned before, the supermassive black holes? We don't really know where they came from. We know that they existed very early on, when the universe was relatively young, let's say even a billion years old or less. It's like walking into a daycare and seeing a bunch of 90-year-old people, like what are they doing here? How could these big things have grown up and become so large and so powerful, so early on? That's a big, big question in astronomy right now."

Black hole
An artist's impression of a black hole bending spacetime. Scientists are still trying to learn more about the cosmic giants. Solarseven/iStock

What are you trying to observe in black holes right now?

"We would really love to be able to see two supermassive black holes merge. With the LIGO gravitational wave detector we've seen or heard or detected many small black holes merging. That's very exciting. But we'd love to see the big ones.

"There's a new NASA X-ray telescope that we're launching, I think this summer or it might get pushed off a little bit, which is going to look at something called X-ray polarization that will tell us essentially the shape of the black hole—something really, really cool to measure.

"And there should be literally hundreds of millions of black holes, just sprinkled throughout the Milky Way. We've only ever really detected about 20 or 30 of them. So one of the things I'm working on is coming up with new ways of finding those other 100 million black holes sprinkled throughout the Milky Way. Some of which could be within 20 or 30 light-years, which is pretty close by in astronomical terms."

What if we could create a black hole right here on Earth?

"Years ago, people were very nervous about the Large Hadron Collider—whether it was going to blow up the Earth. It wasn't as crazy a question as you might think.

"It would be really cool, I think, to be able to make a little miniature black hole. The good thing about miniature black holes is that the Hawking radiation actually is really important because the smaller they get, the bigger the Hawking radiation effect becomes.

"That would be really interesting if we could make a black hole in the laboratory in a relatively controlled manner, study Hawking radiation, or even turn them into little miniature power plants. All of these ideas have popped up in sci-fi over the years. And I think it would really be interesting to see if we could actually do it eventually."

Finally, what do you think is the most terrifying thing about black holes?

"The terrifying thing, but also the coolest thing, I think, is the way they distort time. People talk about black holes, they're so amazing because even light can't escape from a black hole. I get that. But, you know… light can't escape from a cardboard box either.

"But this idea of how time itself is warped? I mean, our entire reality and consciousness is all built around time. I think the most fascinating and potentially terrifying thing about black holes is how they can control time in a way that really nothing else can. As modern, advanced humans, we love controlling things and we can control everything except time."

Artist's impression of black hole
An artist's impression of a supermassive black hole surrounded by a rotating disk of gas and dust. Some black holes are thought to be billions of times more massive than the Sun. NASA/JPL-Caltech