With its mix of hard physics and semi-mystical speculation, Christopher Nolan’s Interstellar is even more of a brain-melter than Inception. It’s a contender for the movie of the year — but here’s the truth about some of its key scientific concepts. Warning: don’t read on if you haven’t seen the movie yet…
You almost certainly can’t travel through a wormhole
In Interstellar, a wormhole is an intergalactic short-cut, like a piece of paper folded over with a hole poked through, as the film has it in one of Basil Exposition’s many interventions. In the movie, passing through this distortion of space and time – conveniently placed near Saturn by ‘Them’ – is as complicated as hopping a fence.
In reality, there’s little evidence that wormholes exist and if they do, they might only exist for nanoseconds or at subatomic scale. Successfully travelling through one big enough would require the manipulation of ‘exotic matter’ – matter with both negative mass and energy – which also probably doesn’t exist beyond the realm of theoretical maths.
Spoiler alert: In the movie the extra-dimensional ‘bulk beings’ are so advanced that they can create workable wormholes, so that’s OK.
What would really happen?: You’d spend a lifetime looking for one and then you wouldn’t be able to use it.
You can’t pass through a black hole and live
Another key scene has astronaut Joseph Cooper (Matthew McConaughey) enter a black hole on a crucial exploratory mission. It’s a rough ride, but he makes it as only Hollywood heroes can. But according to astrophysicist Neil deGrasse Tyson, if you enter a black hole “You’re not coming out, ever… The tidal forces will exceed the intermolecular forces of your flesh and you will snap at the base of your spine.” And then those two halves will snap and snap again and again and again. But hey, it’s a movie.
What would really happen?: It wouldn’t be pretty.
And you wouldn’t try to colonise a planet orbiting a black hole in the first place
Looking for a replacement Earth? “We already have a thousand candidate planets in our catalogue that aren’t orbiting black holes,” according to deGrasse Tyson, “many of which look better than the ones in the film.” It’s like having your pick of houses and choosing that garden shed in the middle of a warzone.
What would really happen?: You’d lose your space exploration budget as soon as you said “black hole”.
You can’t go back in time and change your life
Spoiler alert: Interstellar, the ghost messing with Murphy’s bookshelves is actually Cooper himself. Not Present Dad who she’s begging not to go on this fool’s errand to find another planet for starving earthlings to colonise, but Future Dad who’s reached back in space and time through a Tesseract to tell her to stop him (i.e. himself) leaving. Though of course, if she’s successful, he never goes in the first place and thus can’t come back to tell her to stop him.
What would really happen?: You’d be locked in a never-ending Terminator franchise, but without the guns.
You actually can appear younger than your daughter
Mega-spoiler alert: At the end of the movie, Cooper visits his daughter Murphy, aged 10 when he left, on her deathbed. She is an old woman, but Cooper, now 124, hasn’t aged at all. This is more plausible than it sounds. Time is stretched by huge objects such as the black hole and its surrounds, where Cooper spends much of the film, ageing one hour while those outside its gravitational pull age seven years.
What would really happen?: By the time you’ve bent all the rules of science, 70 late birthday presents would be the least of your worries.
What to say: “Some of the science is known to be true, some is an educated guess, and some is speculation,” Kip Thorne, astrophysicist and Interstellar consultant.
“It’s a movie. Get over it.”
What not to say: “Explain that bit with the paper again.”