Wrinkles in spacetime: The warped astrophysics in Interstellar

[LiberalArkie]

http://www.wired.com/2014/10/astrophysics-interstellar-black-hole



KIP THORNE LOOKS into the black hole he helped create and thinks, “Why, of course. That's what it would do.” ¶ This particular black hole is a simulation of unprecedented accuracy. It appears to spin at nearly the speed of light, dragging bits of the universe along with it. (That's gravity for you; relativity is superweird.) In theory it was once a star, but instead of fading or exploding, it collapsed like a failed soufflé into a tiny point of inescapable singularity. A glowing ring orbiting the spheroidal maelstrom seems to curve over the top and below the bottom simultaneously.

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Thorne sent his answers to Franklin in the form of heavily researched memos. Pages long, deeply sourced, and covered in equations, they were more like scientific journal articles than anything else. Franklin's team wrote new rendering software based on these equations and spun up a wormhole. The result was extraordinary. It was like a crystal ball reflecting the universe, a spherical hole in spacetime. “Science fiction always wants to dress things up, like it's never happy with the ordinary universe,” he says. “What we were getting out of the software was compelling straight off.”

Their success with the wormhole emboldened the effects team to try the same approach with the black hole. But black holes, as the name suggests, are murder on light. Filmmakers often use a technique called ray tracing to render light and reflections in images. “But ray-tracing software makes the generally reasonable assumption that light is traveling along straight paths,” says Eugénie von Tunzelmann, a CG supervisor at Double Negative. This was a whole other kind of physics. “We had to write a completely new renderer,” she says.

Some individual frames took up to 100 hours to render, the computation overtaxed by the bendy bits of distortion caused by an Einsteinian effect called gravitational lensing. In the end the movie brushed up against 800 terabytes of data. “I thought we might cross the petabyte threshold on this one,” von Tunzelmann says.

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http://www.wired.com/2014/10/astrophysics-interstellar-black-hole

[jberryhill]

1. Meanwhile, inside the computer...

...sentient beings arose on a planet orbiting an unexceptional star in a minor galaxy, built nations, fought wars, wrote songs, loved, hoped, and died; and none of the computer programmers noticed.