The interstellar contributions of Kip Thorne, the man Carl Sagan contacted for physics advice

Gautham Shenoy October 7, 2017 11 min

It’s World Space Week, the international celebration of science and technology, and the theme for 2017 is ‘Exploring new worlds in space’. So it is a pleasant coincidence that one of the winners of this year’s Nobel Prize in Physics is a man who showed Carl Sagan, and many others since, one way in which we can explore distant worlds in space – wormholes, the tunnel-like shortcuts that link far-flung regions in spacetime.

Kip S. Thorne is no ordinary physicist. He was one of the youngest full professors in the history of the California Institute of Technology (Caltech), and the Feynman Professor of Theoretical Physics at Caltech until his retirement in 2009. Considered an authority on the astrophysical implications of Einstein’s general theory of relativity, he revolutionised astrophysics, and it was his role as the leading founder and formulator of the scientific vision of the Laser Interferometer Gravitational-Wave Observatory (LIGO) in 1984, that ultimately led to him winning the Nobel – along with Rainer Weiss and Barry C. Barish – “for decisive contributions to the LIGO detector and the observation of gravitational waves”.

If they weren’t widely accepted by fellow scientists and in keeping with the laws of physics, some of Thorne’s ideas would seem like they belong only in a science fiction novel – like using wormholes for interstellar travel, and travelling through time through a wormhole, in effect turning it into a time machine.

Left: Kip Thorne (left) with Robbie Vogt (right), the first LIGO project director, in front of a prototype of the LIGO detectors. (Credit: Archives, Caltech). Right: Kip Thorne at the premiere of ‘Interstellar‘ in 2014 (Source: Frazer Harrison/Getty Images)

Even all of this isn’t quite the reason why Kip Thorne is known outside of scientific circles and to sci-fi buffs in particular. The reason for that is his contribution to popularising science with easily accessible books written for general readers, and especially to two sci-fi projects – each of them path-breaking classics in their own way – Carl Sagan’s novel Contact, and the Christopher Nolan movie, Interstellar.

What sets these two movies apart is their scientific rigour, accuracy, and refusal to break the laws of physics as they were accepted in their time, and at the heart of it lie Kip Thorne and his ideas. For the full story, we need to take a quick stroll on a journey involving a friend seeking advice, a blind date, a failed romance, Steven Spielberg, and the creation of a black hole.

An extract from the Kip Thorne’s preface to his book, The Science of Interstellar

“Sorry to bother you, Kip,” he said. “But I’m just finishing a novel about the human race’s first contact with an extra-terrestrial civilisation, and I’m worried. I want the science to be as accurate as possible, and I’m afraid I may have got some of the gravitational physics wrong. Would you look at it and give me advice?” The ‘he’ was the Cornell University astrophysicist Carl Sagan, speaking to Kip Thorne, at the close of academic year 1984-85, and the novel in question was, of course, Contact.

I’ve typed out the call that started it all verbatim – as related by Kip Thorne in his 1994 book, Black Holes and Time Warps: Einstein’s Outrageous Legacy, a must-read for anyone interested in the topic.

Of course he would help, Sagan was a friend after all. And also because as he says, ‘It would be interesting Carl is a clever guy. It might even be fun’. The novel’s manuscript soon arrived just as Thorne was leaving on a long journey with his wife and son to see his daughter graduate. ‘The book was fun, but Carl indeed, was in trouble’ because Sagan had his heroine, Eleanor Arroway, plunge into a black hole and travel through hyperspace. Impossible, thought Thorne, Carl’s novel would have to be changed. Thorne kept thinking and somewhere during the return journey got the idea of having Sagan use wormholes, despite being initially sceptical himself. Pulling out a pen and paper, Kip Thorne left the driving to his wife and son and stared working out the science, fleshing out the ideas and writing out the equations. By the time they’d returned, Thorne had it all worked out and immediately sent Sagan a long letter, with all the documents, almost a ‘bible’ for wormhole travel if you will. Ideas and suggestions which Sagan accepted with pleasure and incorporated into Contact. Sagan acknowledges this in his Author’s Note in the book saying, “Professor Thorne took the trouble to consider the galactic transportation system described herein, generating fifty lines of equations in the relevant gravitational physics.” Kip Thorne in turn says that had it not been for Sagan’s phone call and the challenge to make Contact scientifically correct, he’d never have ventured into research on wormholes and time machines.

These equations of Thorne and the galactic transportation system which Thorne suggested didn’t just make Contact accurate physics-wise, but also gave thrust to an entirely new area of theoretical research on how wormholes in space could be used for interstellar travel, with the wormhole sequence in Contact in itself helping advance the field of theoretical physics.

As with the story of Contact, the story behind Interstellar too begins with a phone call, and from none other than Carl Sagan.

Keeping the science real: Kip Thorne with Christopher Nolan on the sets of Interstellar.

September, 1980. Kip Thorne is a single father, having separated from his wife. His friend Carl Sagan calls him proposing a blind date, with Lynda Obst, the counterculture-and-science editor for the New York Times Magazine. Thorne agrees and for their first date, the couple go to the premier of Sagan’s Cosmos, with Kip Thorne wearing a baby-blue tuxedo to a glitzy black-tie affair. They’d date on and off for the next two years but the romantic interest would wear off (Thorne thinks it was perhaps his velour shirts and double-knit pants). But Obst and Thorne had laid the foundation for a lasting friendship.

Fast forward to October 2005. Lynda Obst – by now an accomplished Hollywood producer – and Kip Thorne meet for dinner. Over dinner, Obst discusses the outlines of an idea she’d had for a science fiction movie. This would be just the second sci-fi movie she’d be involved in, the first being – coincidentally – Contact, the 1997 Robert Zemeckis-directed adaptation of Sagan’s novel, which had gone on to win the Hugo Award for Best Dramatic Presentation. Obst’s new idea involved wormholes, something Thorne had done pioneering work in, and he was hooked.

Over the next few months, they formulated a vision for a film – a blockbuster grounded from the outset in real science though involving wormholes, black holes, a universe with five dimensions and human encounters with higher-order beings, a film that could give people a taste of the wondrous things that the laws of physics can, and might, create in the universe.

Left: Kip Thorne with Lynda Obst. Right: Cover of Kip Thorne’s book explaining the story and science behind Interstellar. The ‘spoiler alert’ label reads, ‘This book explains the fantastic climax and ending of Interstellar’.

The first director to show interest was Steven Spielberg, who signed on to direct Interstellar in early 2006 after reading Obst and Thorne’s story treatment. And at their first meeting with him, Thorne laid down two critical guidelines for the movie:

1. Nothing in the film will violate firmly established laws of physics or our firmly established knowledge of the universe.

2. Speculations (often wild) about ill-understood physical laws and the universe will spring from real science, from ideas that at least some “respectable” scientists regard as possible.

Spielberg agreed. By the time 2007 rolled in, with the film’s treatment having grown substantially, Obst and Thorne finally converged on Jonathan Nolan (Jonah) as Interstellar’s screenwriter. Jonah brought with him his own new ideas for the film, and Thorne worked with him, discovering ways to make anomalies in the story scientifically possible. But the Writer’s Guild strike in late 2007, Jonah’s commitment to The Dark Knight Rises and finally the death of his father meant that Jonah could get back to working on Interstellar only by early 2010. By June of that year, Spielberg had left the project, unable to reach an agreement with the studio, Paramount on the next phase of the movie.

Enter Christopher Nolan, Jonah’s brother, who knew his brother’s screenplay for the movie only too well. If Jonah had added his own ideas, Nolan would bring in his own and alter the direction of the movie’s story. On his first meeting with Nolan, Thorne repeated his two non-negotiable guidelines for the science of the movie. From there it was smooth sailing, and whenever any of Nolan’s new ideas for the movie seemed to violate the guidelines, Thorne found a way to make them work, except for the one time where Nolan wanted to have a character travel faster-than-light. Nothing doing, said Thorne, getting his way after heated discussions that lasted for almost two weeks.

Meanwhile, there was the little matter of special effects and how to realistically depict wormholes, and with time dilation being a big part of Nolan’s ideas, the challenge lay in creating the only thing that could make this scientifically accurate, a massive black hole spinning at nearly the speed of light. Problem was, no one had seen a black hole. So Kip Thorne helped build one.

The fast-rotating, supermassive black hole, Gargantua, from Interstellar, surrounded by its accretion disc.

With the team from Double Negative VFX led by Paul Franklin on board, Thorne generated many theoretical equations for the wormholes, sending the VFX team sheets upon sheets of heavily researched papers, based on which the team wrote a special software that would then render the simulations. And thus finally create the black hole Gargantua, complete with its accretion disc – widely considered to be the most accurate simulation and realistic portrayal of a black hole on screen. ‘Moderately realistic’ says Thorne – then enhanced – because there were other simulations that were more accurate, but which would’ve been confusing to viewers and not as aesthetic looking. Double Negative would end up winning the Oscar for Best Visual Effects.

The final result of all this was a sci-fi movie that has been hailed as amongst the most scientifically accurate ever. Except for the one place, that Thorne says makes him cringe every time he sees it – the ice clouds on Dr. Mann’s planet, for the simple scientific reason that these clouds go beyond what the material strength of ice would be able to support, given the planet’s gravity.

Nonetheless, Interstellar on its release – with Kip Thorne credited as Executive producer – was praised all around for its science, with theoretical physicist Michio Kaku calling it “the gold standard for science fiction movies for years to come” and George R. R. Martin saying it is ‘the most ambitious and challenging science fiction film since Kubrick’s 2001’. Interstellar would go on to make almost $700 million worldwide, showing that science need not be sacrificed for fiction in a science fiction movie in order to be a critical or commercial success. It helps to have someone like Kip Thorne on board of course.

Kip Thorne, who continues to work on gravitational waves, has spoken of working on a science fiction novel and mentioned in passing about a movie project that he, Lynda Obst and his old friend Stephen Hawking have been discussing. Will winning the Nobel change those plans? Only time will tell.

And speaking of plans, I do hope that you, dear reader, are free on the evening of October 14th, that’s next Saturday, to join me, a few members of the FactorDaily team and some fellow sci-fi fans in Bangalore, to watch Blade Runner 2049 in all its IMAX glory. Because we’re giving away 6 tickets to what is being already considered possibly the greatest sequel ever.

All you have to do to stand a chance to win one of these tickets is tell us which one among the 64 pieces in the New Worlds Weekly column (so far, including this one) did you like the best, and why? Tweet the link to the piece with your comments with the hashtag #NWWonFD or post it on Facebook with your reasons why you liked that particular with the tag #NWWonFD, and your name will be entered into a lucky draw. We’ll announce the winners next Thursday so you can make your plans accordingly.

So go on and participate. Wish you all the best, I hope you win and hope to then catch you in person – popcorn in hand – to enjoy Blade Runner 2049.

Live long and prosper!


Lead Image: Via Time. ©Ricardo DeAratanha—Los Angeles Times/Getty Images
Update (7 October 2017, 1.51 PM IST): Deleted two repeating sentences.