MU-5: The Hollywood Connection!

The sci-fi movie, Interstellar, has two exotic concepts of physics: wormholes and black holes. If you neither know nor care about what either of those things are, don’t worry: this still makes for interesting reading.

When Christopher Nolan made Interstellar, he had a problem: while physicists and sci-fi fans may know what wormholes and black holes are, how would he render it onscreen accurately? Willing suspension of disbelief or not, sci-fi fans would tear into his movie if the rendering were obviously wrong in any way.

(In case you don’t know, a “renderer” is a piece of software that draws stuff on screen. The term will be used repeatedly, so it’s good to know).

Nolan turned to Kip Thorne, a retired astrophysicist who has always wanted to popularize relativity to the layman, for help:
“So he (Paul Franklin, Nolan’s computer graphics man) asked Thorne to generate equations that would guide their effects software the way physics governs the real world...Thorne sent his answers to Franklin...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.”

The next step was rendering a black hole:
“But black holes, as the name suggests, are murder on light.”
Since they couldn’t show/draw a black hole (it was black), it would have to be depicted by what effect it had on everything around/near it. This was a problem since existing rendering software assumes (reasonably) that light travels in straight lines. Sadly for Franklin, that’s not true around black holes. So they had to write a new renderer for the black hole. This was so mathematically intensive a task that:
“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.”

When they applied the new algorithm for objects around a black hole, here’s what the rendering software made it look like:
“Rather than looking like Saturn's rings around a black sphere, the light creates this extraordinary halo.”
This was so weird that the team felt there was a bug in the software!
“But Thorne realized that they had correctly modeled a phenomenon inherent in the math he'd supplied…Thorne thought, “Why of course. That’s what it would do.”
In other words, Thorne got something out of all this that he didn't expect: a scientific discovery!

To summarize, the maths of general relativity was used to create rendering software which then showed how something would appear, something even physicists hadn’t known until they saw it. Quantitative understanding can sometimes become qualitative understanding after all!

Comments

Post a Comment

Popular posts from this blog

Student of the Year

Image
As a toddler, my daughter loved Alia Bhatt’s songs, esp. the ones from Student of the Year . (That movie did have many good songs and well-choreographed dances). Fast forward to present day, when she is 12 yo. She rarely watches Hindi movies now, but one of the few ones she likes of late, Raja aur Rani ki Prem Kahani has, yes, Alia Bhatt.   If I had any hopes that there was anything to be read in the name of her toddler-time favorite ( Student of the Year ), they have been dashed. Our conversations come exam time are perfectly captured by this photo and its caption: In fact, the pic below captures how she and I look at her answer sheets – me intently, she with an expression of “It’s over, so why are you even looking at it?”   Of late, we pull her leg and tell her that she isn’t showing any signs of academic prowess, she’d better find a rich guy to marry. Some time later, she showed us this meme on the Internet: “Me No Study, Me No Care Me Go Marry Millionaire ...
Read more

Why we Deceive Ourselves

In their book, The Elephant in the Brain , the authors describe this weird aspect of deception that we practice: deceiving ourselves! That is so weird: “If our minds contain maps of our worlds, what good comes from having an inaccurate version of these maps?” The Sigmund Freud school of thought treats self-deception as a defense mechanism, “a way for the ego to protect itself”. The mind seeks to protect itself from anxiety and other negative emotions. Many object to this reasoning: since accurate information is so critical to our survival, surely distorting information would be dangerous. Wouldn’t the goal of protecting our self-esteem have been better achieved by making the brain’s self-esteem mechanism stronger instead? The new school of thought explains self-deception as “primarily outward-facing, manipulative, and ultimately self-serving”. This is based on Thomas Schelling’s work on game theory: “In a variety of scenarios, limiting or sabotaging yourself is the winn...
Read more

Europe #3 - Innsbruck

The last city we visited in Europe was Innsbruck in the Austrian Alps. After the cold and windy experience (at times) of Paris and Netherlands, Innsbruck was a wonderful change – it didn’t feel that cold, it was not windy all of which made it easy to walk around. Something absolutely necessary given how scenic the place is.   Since the hotel check-in time was much later in the day, we left the baggage and went to the Swarovski HQ-cum-museum about an hour by bus from Innsbruck. The crystal exhibits were brilliant – colorful, bright, shiny. Jewellery aside, it was a display of what one can do with crystals. While my wife and daughter loved the jewellery, I liked the superhero themed exhibits of Batman, Spiderman, the Hulk, and Star Wars. We didn’t buy anything there, though we did buy stuff in the Swarovski store in Innsbruck – jewellery, not the superhero stuff.   Innsbruck is a major tourist attraction during the skiing season but now in summer, we saw many groups of ...
Read more