November 08, 2014

Christopher Nolan’s "Interstellar": Is The Science Accurate?



IT’S hard to see what could go wrong with the new Christopher Nolan film, Interstellar. One of the world’s leading theoretical physicists, Kip Thorne, served as adviser. It is said to contain a simulation of a black hole so accurate that it caused film journalists to write “spheroidal maelstrom” and “accretion disc”. And it contains Anne Hathaway looking lovely in a space suit. 
What’s not to like? Then you watch it and note that it involves using wormholes (basically black holes with an exit) to commute between stars. And that everyone keeps referring to the mysterious “gravity equation”. Oh yes, and it contains the phrase: “Love is the one thing we are capable of perceiving that transcends dimensions of time and space.” A line so silly that it may become immortal.

To help sort the good science from the bad, we took two of the world’s leading cosmologists — Martin Rees, astronomer royal and emeritus professor of astrophysics at Cambridge University, and Carlos Frenk, professor of fundamental physics at Durham University — to see the film and explain any (worm) holes in its plot. Below are 10 propositions suggested by the film and the professors’ responses to them:

1. You can travel through wormholes: TRUE (possibly).
The basic premise of the film is that Earth is enduring an unspecified environmental disaster that is causing deathly dust clouds in the American midwest. Humanity needs to find somewhere else to live, fast, which is where Cooper (Matthew McConaughey) and Amelia (Hathaway) come in: they are going to set off and find another planet. Via wormholes. This form of transport is “speculation, but it’s not crazy”, Rees say. “The conventional view on black holes is that you go in and you are squashed. But it is possible that … there is a limit to how much you are squashed, and you come out the other side.” The equations don’t prove it but, he says, “they don’t rule it out completely”.

2. If you were to travel through a wormhole, it would be a bumpy ride: TRUE (probably).
Travelling through a wormhole is portrayed as a slightly more uncomfortable version of travelling on the London Underground’s Northern Line: rattly, a bit hot, and with unnerving moments when it all goes dark.
“If you were to have a wormhole that was big enough for someone to go into without being torn apart it would have to weigh thousands of times more than the sun,” says Rees. And if you did, Frenk adds, “it would eat up everything” and we would all be sucked into its black abyss, never to escape. Also like the Northern Line.

3. You can explain wormholes with a folded piece of paper and a pencil: TRUE.
Early in the film, one astronaut explains wormholes to his colleagues by folding up a piece of paper, then puncturing it with a pencil. “It was a good explanation. That’s the way I’d explain it if I was giving a lecture,” says Rees. Although you suspect that Rees probably wouldn’t add afterwards: “That’s relativity, folks!”

4. Wormhole travel keeps you young: TRUE.
As Cooper heads off he is told that for every hour he spends on the new planet, seven years will pass back on Earth. Cue horror for him (will he see his daughter again?) and equal horror for the viewer as, back at base camp, the inevitable CGI liver spots are applied to Mich­ael Caine’s face as 23 Earth years pass in the three hours that Cooper is on the new planet. Hokum, surely? Amazingly, no.
“They got that absolutely right,” says Rees. “If you go to another star and come back, people would have aged a lot. That’s what happens if you go very fast.” Although, adds Frenk, we’re not talking about ageing by “a few years. We’re talking about billions or hundreds of millions of years.” So everyone would be dead.

5. The universe has other planets that could support life: TRUE.
“A major discovery in the past decade or so is other planets around stars,” says Frenk. “Ten years ago the only planets we knew about were in the solar system.” Now, says Rees, “we know most stars have them. If you were to travel far enough through interstellar space you would indeed expect to find another planet like the Earth.” Whether it would have Matt Damon on it when you got there is another question.

6. Time travel is possible:

“If you can travel faster than the speed of light you can travel back in time,” says Frenk. “We don’t know if this is possible. Maybe you can.” But, say the professors, it is not likely, owing to the problem of logical consistency that is best summed up by the “killing-your-mother paradox”.
“If you can travel back in time to when your mother was a young girl, you can pull out a gun and shoot your mother before you were born,” Frenk says. Which, given that you were there to shoot her, obviously can’t have happened. There are two ­options, Rees says: “One is that there is something that prevents time travel in the past. Or time travel in the past is allowed but there is some other constraint ­applied by science that would stop contradictory behaviour.”

7. Solve “the gravity equation” and you will be able to communicate through space-time: FALSE.
There is no such thing as “the gravity equation” in real life. There are famous equations that explain how gravity behaves, but these have, as Rees says, “been solved for a hundred years”.

8. Genius physicists still use blackboards to do their equations: FALSE.
Murph is shown puzzling over equations on blackboards, shorthand for “I’m an unorthodox and determined genius” (see: Good Will Hunting, Apollo 13, you name it). However there are clues that her character isn’t quite the genius implied because, as Frenk says: “Some of the symbols were backwards.” Besides: “Nobody does science like this any more on blackboards.”

9. This is the most realistic science fiction film ever: FALSE.
Not suggested by the film but a suggestion that has been swirling around it. So is it? “Certainly not,” says Frenk. “2001: A Space Odyssey stuck to the script of science a lot more closely.” It is, they agree, more science fantasy than science fiction. “This one takes enormous liberties,” says Frenk, “but there’s nothing wrong with that. It’s fun. Which is what it’s supposed to be. Science is hard. The entertainment factor of this was 8 or 9.” And if you were to mark the physics out of 10? “We won’t give it a mark,” says Rees, smiling slightly . “It wasn’t sitting for a science examination.”

10. Love can transcend dimensions of space and time: FALSE.
No, it can’t. And you really don’t need the ­astronomer royal to explain this.

By Catherine Nixey

With thanks to The Australian 

Above: Trailer from "2001: A Space Odyssey". Made in 1968 the special effects were way ahead of their time and still hold up to today's CGI and other movie technology.

Above: Trailers from Hell's take on this movie.

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