The Physics Behind “Interstellar’s” Visual Effects Was So Good, it Led to a Scientific Discovery

While he was working on the film Interstellar, executive producer Kip Thorne was tasked with creating the black hole that would be central to the plot. As a theoretical physicist, he also wanted to create something that was truly realistic and as close to the real thing as movie-goers would ever see.

On the other hand, Christopher Nolan – the film’s director – wanted to create something that would be a visually-mesmerizing experience. As you can see from the image above, they certainly succeeded as far as the aesthetics were concerned. But even more impressive was how the creation of this fictitious black hole led to an actual scientific discovery.

In short, in order to accurately create a visual for the story’s black hole, Kip Thorne produced an entirely new set of equations which guided the special effects team’s rendering software. The end result was a visual representation that accurately depicts what a wormhole/black hole would look like in space.

This was no easy task, since black holes (as the name suggests) suck in all light around them, warp space and time, and are invisible to all but X-ray telescopes (due to the bursts of energy they periodically emit). But after a year of work by 30 people and thousands of computers, Thorne and the movie’s special effects team managed to create something entirely realistic.

Relying entirely on known scientific principles, the black hole appears to spin at nearly the speed of light, dragging bits of the universe along with it. Based on the idea that it was once a star that collapsed into a singularity, the hole forms a glowing ring that orbits around a spheroidal maelstrom of light, which seems to curve over the top and under the bottom simultaneously.

To simulate the accretion disk, the special effects team generated a flat, multicolored ring and positioned it around their spinning black hole. Then something very weird and inspiring happened.

“We found that warping space around the black hole also warps the accretion disk,” explained Paul Franklin, a senior supervisor of Academy Award-winning effects house Double Negative. “So rather than looking like Saturn’s rings around a black sphere, the light creates this extraordinary halo.”

The Double Negative team thought it must be a bug in the renderer. But Thorne realized that they had correctly modeled a phenomenon inherent in the math he’d supplied.

“This is our observational data,” he said of the movie’s visualizations. “That’s the way nature behaves. Period.” Thorne also stated that he thinks he can get at least two published articles out of it.

But more important than that is the fact that Thorne, a thoroughgoing scientist and lover of the mysteries of space and physics, has a chance to show a mass audience some real, accurate science.

The movie premiers in North America on November 7th.

Christopher Nolan and Kip Thorne explain the science behind creating the movie’s black hole.

Further reading: Wired