Much has been made of the mind-bending visual effects in Interstellar. But the methods created by the film’s Oscar-nominated visual effects team may have more serious applications than wowing movie audiences—they could actually be useful to scientists, too. A new paper in Classical and Quantum Gravity tells how the Interstellar team turned science fiction towards the service of scientific fact and produced a whole new picture of what it might look like to orbit around a spinning black hole.
Director Christopher Nolan and executive producer (and theoretical physicist) Kip Thorne wanted to create a visual experience that was immersive and credible. When they began to construct images of a black hole within an accretion disk, they realized that existing visual effects technology wouldn’t cut it—it created a flickering effect that would have looked bad in IMAX theaters. So the team turned to physics to create something different.
“To get rid of the flickering and produce realistically smooth pictures for the movie, we changed our code in a manner that has never been done before,” Oliver James, chief scientist at visual effects firm Double Negative, said in a release. “Instead of tracing the paths of individual light rays using Einstein’s equations—one per pixel—we traced the distorted paths and shapes of light beams.” That led to a new set of code they called DNGR—the Double Negative Gravitational Renderer.
But the team soon realized that the images produced using DNGR code could be used for much more than a fictitious interstellar trip. They began to use the code to conduct simulations of how a weird space surface called a “caustic” might affect images of star fields near black holes in a process known as “gravitational lensing.” Their simulations showed that as caustics are dragged around the sky by the spinning force of a black hole, they stretch around the hole again and again, affecting how stars look. This both creates and obliterates images of stars, creating up to 13 images of a star as the caustic flings images out of the black hole.
Think that sounds like a really cool visual? So do scientists. As astrophysicist Kip Thorne of Cal Tech, who co-authored the study, says, “This new approach to making images will be of great value to astrophysicists like me. We, too, need smooth images.”
Here’s more info on how the team created its visual effects: