Wired has a fun piece about physicist and black-hole guru Kip Thorne’s work on the film Interstellar, which comes out November 7. We’ve known the premise of the film for a long time: Earth is a disaster, the human race is on the verge of extinction, and mankind must find a new home. Alas, space is big. It would take way too many human lifetimes to travel to our nearest possible second homes. The only way to get there is through a wormhole–a spacetime tunnel linking two distant regions of the universe.
Wormholes, also known as Einstein-Rosen bridges, are not the same as black holes. Under normal circumstances, if you fall into a black hole it will crush you out of existence, not fling you to a distant corner of the universe. But black holes behaving in various ways could, in theory, open up wormholes. With Thorne’s guidance, apparently Nolan decided that a massive black hole (called Gargantua) spinning at nearly the speed of light would suffice.
What’s interesting is how much the black hole in Interstellar looks like the models that the scientists of the Event Horizon Telescope (EHT) have generated to study the black hole at the center of the Milky Way, Sagittarius A*. (The EHT is an international group of astronomers who are linking together a worldwide array of radio telescopes to observe black holes at event-horizon scales. More here.) In other words, the black hole in Interstellar is really, truly what scientists expect real-life astrophysical black holes to look like. Compare the images over at Wired with this simulation by Avery Broderick, a theorist at the University of Waterloo and the Perimeter Institute who has been part of the EHT collaboration since the beginning:
Christopher Nolan’s black hole has higher production quality, but both images show the same thing: a glowing accretion disc orbiting the hole; a “shadow” feature caused by gravitational lensing; a thin ring marking the last photon orbit, in which light rays circle the hole many times before either escaping or falling in. The EHT astronomers use their models to predict what their instrument, once it reaches full strength, might see–how Sagittarius A* should look when viewed from Earth by a worldwide array of millimeter-wave radio telescopes. (Presumably if you were on the verge of falling into Sagittarius A*, you’d see something more like what’s in the movie.)
So when you watch Interstellar, keep this in mind: that black hole Matthew McConaughey flies through? Scientists think the black hole at the center of our galaxy might look a lot like that. And within the next couple of years radio astronomers might be able to take its picture.