14 Things That Happen In "Interstellar", Ranked By Scientific Accuracy

An astrophysicist ranks parts of Interstellar, from the totally plausible to the "you'd definitely need aliens for that". SPOILERS AHEAD, of course.

So, does the science in Interstellar make sense?

Professor Kip Thorne, the science advisor and executive producer of Interstellar, has written an excellent book called The Science of Interstellar in which he describes several plot points and how he thinks they could be made to agree with our understanding of physics.

That's not what we're doing here. The goal of this post is not to detract from the storytelling or criticise the writers (it's fiction, after all!) but rather to give you an idea of what astrophysicists have actually seen, and how that compares with what you see in the movie.

1. There's a solar-powered drone that stays up for decades.

Warner Bros

Depends on design, but this is probably possible. The solar-powered Opportunity Mars rover has been going strong for ten years, and it's on Mars, which is further away from the sun than we are.

(It seems really unlikely that Cooper would be able to hack into the drone though. Did all world governments use the same guidance programs, accessible via short-range wi-fi?)

Verdict: Believable.

2. There's a black hole that looks like this.

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Supermassive black holes exist and are very common in the Universe. We have one in the centre of our own galaxy, the Milky Way – in fact, we’ve seen supermassive black holes in the centers of nearly every galaxy we’ve studied. Ours is called Sagittarius A* and is due to rip a gas cloud to shreds soon.

The appearance of the black hole in Interstellar is based on real physics simulations led by Kip Thorne, so that's accurate too. It turns out Hollywood special effects companies can do hardcore physics visualisations in a fraction of the time that universities can, because money.

And the shape of the light surrounding the black hole in the film makes sense. Black holes, like all massive objects, bend spacetime around them, which in turn bends light around them. This is called gravitational lensing, and we see it when light from behind the black hole is bent around it in an "Einstein ring" shape. Depending on how you approached the black hole, you could definitely see a bright halo around the hole as well as light from an accretion disk of matter swirling into the black hole.

Verdict: Pretty reasonable.

3. There's an artificial wormhole that looks something like this.

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A wormhole is a tunnel through the fabric of space and time that lets you jump between two distant places in the universe. While we've never actually seen one, they are a perfectly reasonable possibility in the realm of pure theory.

But wormholes are impossible for us to build without massive changes in our understanding of physics. You'd need a type of exotic matter with negative mass that, sadly, probably doesn't exist and can't be made.

The appearance of the wormhole in the film was based on real physics simulations, led by Kip Thorne, a world expert on wormholes. So while they may be impossible to construct, the film version was as accurate as it could be.

But let's say the wormhole did exist, and were traversable. What they look like on the inside (and how long it takes a spaceship to get through one) would be a total guess – especially as the extreme warping of spacetime would also very likely rip your ship apart.

Verdict: Pretty sound, in a theorist sort of way.

4. Time is slowed down on the planet that orbits the black hole.

Warner Bros / Via quora.com

Just as gravity bends space around massive objects, it also slows down time. This effect is called time dilation, and is the reason your watch runs very slightly slower on the ground than it would if you were standing at the top of a tall tower.

Assuming a planet could orbit very close to a supermassive black hole without being destroyed (we'll get to how possible that is later), and assuming the black hole was rapidly spinning, it would be possible to have time slow down to the extent that is represented in the film. (Whether or not a black hole could be spinning quite this fast is an open question.)

This is actually one of the film's most accurate (and awesome!) bits of physics. But there wouldn't be any "time shift zone" outside of which the time dilation is not occurring. It's a gradual change as you move farther from the black hole.

Verdict: Plausible.

5. Getting to Saturn takes two years.

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Probably not possible with today’s technology. The New Horizons spacecraft crossed Saturn’s orbit in about two years, but it wasn’t attempting to rendezvous with the planet, so it didn’t have to match the orbit or slow down. Unless the Endurance was designed to shoot straight into the wormhole, and the orbits were aligned exactly right, such a fast mission would likely require some wildly advanced propulsion technology.

Verdict: Maybe in the future.

6. There's a planet orbiting a black hole.

Warner Bros / Via interstellarfilm.wikia.com

Some theoretical physicists may argue this point, but the possibility of a planet like that in the film existing in the real universe seems highly unlikely. Let's assume the black hole is 100 million times the mass of the Sun, and spinning rapidly. If the planet were close enough to a black hole to have its time slowed down as much as that, it would almost certainly have been ripped apart by something called the tidal force – the difference between the gravitational pull on the near side of the planet versus the far side.

Even if it survived that, it'd be irradiated by x-ray radiation and probably smashed by other things falling into the black hole. It also couldn't have formed so close to the black hole, so unless it was in the process of falling in (which would make it a lousy candidate for a new home world), it would take a lot of really unlikely events to put it there.

Sunlight would be another issue for the planet, because there wouldn't be any if there's no star. The black hole would be a poor source – the accretion disk produces light, but mostly in the form of x-rays, and those would fry the planet's atmosphere.

Putting all that aside and imagining that it did exist, landing on such a planet is going to be a problem. You'd have to catch up to it, and somehow land without orbiting, because if you were that close to the black hole, any small orbital error could send you past the event horizon and into the hole. Getting off the planet (and away from the black hole) would also be incredibly difficult, since you'd have to achieve escape velocity from the hole, which at that distance is nearly the speed of light. You wouldn't get away without using way more fuel than you'd use on a trip to one of the other planets. Not a great plan.

Verdict: Maybe plausible if everything is set up exactly right, but fantastically unlikely.

7. The black hole-orbiting planet has huge waves.

Warner Bros / Via interstellarfilm.wikia.com

If a planet had 130% Earth gravity and a solid surface covered in water, wind-driven waves should be smaller, not larger, than Earth's ocean waves. If they were tsunamis, they'd still have to be accelerated by some kind of seismic event, and they wouldn't be periodic. Tidal forces from the black hole can't be to blame, because those would just create a bulge on either side of the planet, not big waves.

In his book The Science of Interstellar, Kip Thorne suggests that the planet is somehow nodding back and forth and the waves come from that. But we see no current pulling the water one way or another between the waves, so where does all the water come from?

Verdict: As unlikely as the planet existing in the first place.

8. The mysterious "gravity equation".

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It's not entirely clear what this equation is – the equations of general relativity are already known, so it can't be them. It's implied it has something to do with merging

quantum mechanics to gravity, which is what string theory and loop quantum gravity try to do. There isn't just one equation that governs this stuff, though, as far as we can tell.

As for Professor Brand's work to solve gravity equation: This is not even close to what doing theoretical physics is like. You don't just sit in a room by yourself for several years, writing down equations. Why wouldn't he talk to colleagues, put together a large research group? Where are the graduate students? Could he not recruit a single postdoc? This is an annoying common stereotype, but it's not remotely plausible.

Verdict: Far-fetched.

9. There's isn't really a proper flight plan for visiting the candidate planets.

Warner Bros / Via imdb.com

Space travel isn't done on a whim (see: the Rosetta mission). In real life they definitely would have charted this all out, including planning for every contingency, before they got to Saturn. They wouldn't be working it out upon arrival in the other galaxy. Sure, they were in a massive hurry to leave Earth, but they also had two years in the solar system to discuss it, and even had easy contact with the scientists back home.

Verdict: Very poor space-travel etiquette.

10. The universe has a fifth dimension.

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If there were an extra-dimensional space in which our universe were embedded, then it's true that gravity could probably pass through that space, as the film suggests. It's not clear how the extra dimension would be disconnected from our own dimension of time, but if it was, then maybe you could travel through it to see different times. However, we've seen no evidence for extra dimensions in our universe (yet).

Verdict: This is getting pretty speculative.

11. A planet has frozen clouds.

Warner Bros / Via interstellarfilm.wikia.com

Ice is too heavy to form clouds that just magically hang in the air. Even the film's science advisor Kip Thorne isn't sure about them. "These structures go beyond what I think the material strength of ice would be able to support," he told Science magazine. "Every time I watch the movie, that's the one place where I cringe."

Verdict: Pretty but sadly not possible.

12. They collect "quantum data" from a black hole.

Warner Bros / Via quora.com

Anything that gets close enough to the singularity at the center of the black hole to learn something about quantum mechanics would be stretched to spaghetti (or "spaghettified," to use the technical term) and destroyed. As for getting the quantum data out? No way. You're in a black hole.

Verdict: A good excuse to throw main character into a black hole.

13. Someone jumps into a black hole...

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Not a good plan. How far you have to fall into the black hole before you're spaghettified depends on the mass of the black hole, but there'd be no way to stop your descent once it started. As for what it's like once you get inside (pre-spaghettification), no one has any idea.

Communication would also be impossible if you were inside the event horizon of a black hole. Inside a black hole, all paths curve toward the singularity, so signals would be unable to move laterally or away, even if your conversation partner is inside the hole with you.

Verdict: A very bad idea.

14. ... and ends up somewhere that isn’t inside the black hole.

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Strictly speaking, there are solutions to the equations of general relativity that would mean the interior of a black hole could lead somewhere else (though the journey would likely be unpleasant to say the least). On the other hand, there's always the super-advanced-aliens-who-can-control-gravity option.

Verdict: It would be a good idea to make sure you have already made arrangements with the super-advanced fifth-dimensional aliens before you go in.