Oscar-nominated movie ‘Interstellar’ team has turned science fiction into science fact by providing new insights into the powerful effects of black holes.
In a paper published in the journal Classical and Quantum Gravity, the team describe the innovative computer code ‘Gargantua’ that was used to generate the movie’s iconic images of the wormhole, black hole and various celestial objects, and explain how the code has led them to new science discoveries.
Using their code, the Interstellar team, comprising London-based visual effects company Double Negative and Caltech theoretical physicist Kip Thorne, found that when a camera is close up to a rapidly spinning black hole, peculiar surfaces in space, known as caustics, create more than a dozen images of individual stars and of the thin, bright plane of the galaxy in which the black hole lives. They found that the images are concentrated along one edge of the black hole’s shadow.
These multiple images are caused by the black hole dragging space into a whirling motion and stretching the caustics around itself many times.
It is the first time that the effects of caustics have been computed for a camera near a black hole, and the resulting images give some idea of what a person would see if they were orbiting around a hole.
The discoveries were made possible by the team’s computer code, which mapped the paths of millions of lights beams and their evolving cross-sections as they passed through the black hole’s warped spacetime.
The computer code was used to create images of the movie’s wormhole and the black hole, Gargantua, and its glowing accretion disk, with unparalleled smoothness and clarity.
Early in their work on the movie, with the black hole encircled within a rich field of distant stars and nebulae instead of an accretion disk, the team found that the standard approach of using just one light ray for one pixel in a computer code–in this instance, for an IMAX picture, a total of 23 million pixels–resulted in flickering as the stars and nebulae moved across the screen.
Co-author of the study and chief scientist at Double Negative, Oliver James, said: “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. 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.”
Co-author of the study Kip Thorne said: “This new approach to making images will be of great value to astrophysicists like me. We, too, need smooth images.”