Last week, Christopher Nolan’s space epic Interstellar opened to audiences around the world.
It has already received plaudits, and criticism alike, for the way it tackled some complex science, but just how much did it get right?
MailOnline spoke to President of the Royal Astronomical Society Professor Martin Barstow, space science writer Lee Billings - author of Five Billion Years of Solitude - and Mat Kaplan from The Planetary Society to see where the movie fell short - and where it was right on the money.
1. Wormholes don't exist - as far as we know
In the movie our intrepid explorers use a wormhole placed near the orbit of Saturn in order to travel to another planetary system. As explained in the movie, this involves ‘bending’ space meaning people can travel huge distances almost instantly.
The analogy used is if you fold a piece of paper you could travel between two distant points of the paper almost instantly. But is such a thing theoretically possible?
Professor Barstow: ‘I don’t think they really exist. Explaining how one might work is really in the realm of science fiction. There’s no direct evidence such things exist in the universe.
'We know about black holes, but the idea of something connecting different parts of space is very much an idea in its infancy.
But, from a dramatic point of view you’ve got to have something like this in the film like that otherwise it doesn’t work.'
Lee Billings: 'The thing that gets to me the most is it simultaneously makes interstellar travel look easier and harder than it actually is.
'What is appealing is saying maybe there are wormholes and we can just have a wormhole through space and travel through five dimensions.
'But saying that we have to rely on borderline miracles of physics makes it easier, but also makes it way harder. We have no idea if stable wormholes exist on a macroscopic scale.
'It seems a lot easier to do it the hard old-fashioned way, one that doesn’t rely on miracles; maybe you could rely on solar sails [for propulsion], and take your time to get between the stars.'
2. You can't survive in a black hole...
In one of the film’s key sequences towards the end, protagonist Cooper detaches himself from the Endurance spacecraft to reduce its weight and enable Anne Hathaway's character Brand to reach the other habitable planet.
Once inside the black hole - named Gargantua - he ejects from his spacecraft before entering a 2001: A Space Odyssey-esque light sequence. But could someone really survive in a black hole?
Professor Barstow: ‘No. The gravitational field is extremely intense and changes very quickly. The idea is that anything that falls into it becomes like spaghetti, stretched out by gravity.
'So there’s no chance that anything or anybody could survive in a black hole. Communicating out of one is also impossible.’
WAS IT THE MOST ACCURATE BLACK HOLE EVER?
When calculating how to model a giant black hole in the film, the team said they created one of the most accurate depictions of such an object, which could explain what they would actually look like.
The science of determining what a black hole would look like was left to astrophysicist Dr Kip Thorne, who was the film's executive producer.
He found that the black hole warps space so that it looks sort of like a funnel with a black circle in the middle.
It draws in matter from its surroundings into an accretion disc, shining incredibly brightly and brilliantly.
This had previously been known - but the visual effects team found when they modelled it, the gravity of the black hole twisted the disk of gas into weird shapes.
This created a rainbow of fire across the top of the black hole.
When they used a flat accretion disc around the spinning black hole in their model, the warped space also warped the disk.
The depiction has apparently spawned two scientific papers.
Lee Billings: I think if astronauts ended up getting as close to the accretion disc around a supermassive black hole, as they did in the film, in reality they would have a bad time.
'Those things are going to be pouring off hard radiation from the super-heated material that piles up around the event horizon, and so it kind of seems a big stretch to think you can just blissfully glide over it and not melt.
'The notion of having habitable planets there is also relatively dubious.'
3. ...but you can orbit a black hole
In the film Brand orbits the black hole and swings round to reach one of the planets in this exoplanetary system. Plausible or implausible?
Professor Barstow: ‘You can orbit one as long as you don’t get too close.
'In astronomy we see lots of systems in orbit around a black hole, usually a system with a star.
'You can certainly see those systems but once you get inside the event horizon [of the black hole] dramatic physics happen, and you spiral in and are consumed.'
4. Planets could exist around a black hole but they probably wouldn't be habitable
The explorers visit a planetary system that not only orbits a black hole, but also has potentially habitable planets. While the idea of such planets being livable might seem far-fetched, it's apparently not that unrealistic.
Professor Barstow: ‘There's no reason why they couldn’t [orbit a black hole], although nobody’s ever detected one.
'The problem would be how stable a system is. I don’t know enough about the calculations on that.
'So it’s a bit hard to say for sure if you could have it. But provided anything in orbit is outside the safety limit, it’s perfectly possible. What’s more likely is a star orbiting, and a planetary system around that star. Any planetary system associated just with a black hole would probably be consumed.'
Lee Billings: 'I think Interstellar is a movie for physicists, not for planetary scientists.
'And I think you can see that in what they emphasise what's accurate and true science, and what’s not.
'There are a lot of problems with the planets. For example, there’s that planet with huge tides, but the water itself is no shallower than your ankles or your knees.
'It’s not clear what’s causing those crazy tides, maybe the black hole, but if it’s pulling that hard then it would manifest in other ways beside mile-high waves.'
5. There's not really such a thing as a 'gentle singularity' as far as we know
David Gyasi's character Romilly claims in the film that the black hole has only a 'gentle singularity' at its core, which might account for some of the less deadly conditions in the planetary system they visit. But is there even such a thing as a gentle singularity?
Professor Barstow: 'What’s important is that you can have black holes with different masses.
'So the singularity is essentially the central point, but there’s this concept that all black holes are finite mass that don’t just disappear into space, and that’s how we detect black holes because mass influences material around them.
'In a simplistic view of physics, the masses collapse down and depending on how much mass is there, they must occupy different volumes of space.'
Mat Kaplan: 'There is some scientific basis for that. We still know so little about what happens near a black hole.
'We have the theory, I guess, to the event horizon, but beyond that nobody knows. I think they are fairly certain with a black hole the size of Gargantua, you can get things like that if it's large enough.
'But until we actually get to explore one, if that ever happens, or have some instruments that can examine it, it's really all theory.'
6. The way the astronauts age in the movie due to time dilation was accurate
The crew in the movie age much slower than their counterparts on Earth owing to the effects of time dilation, something theorised by Albert Einstein. The theory dictates that as people travel nearer to the speed of light, time goes slower, something that has been experimentally proven on Earth.
Professor Barstow: ‘That’s pretty much established.
'That comes from special relativity, which is the theory proposed by Einstein, the idea that bodies travelling at different speeds experience time differently.
'For example, the astronauts that went to the moon that travelled faster than any human being would have aged a tiny bit more slowly than anybody else on Earth, but not enough to notice.
'But once you get up to near the speed of light, and that’s quite a hard thing to do, you would notice these effects. And we see them going on when we observe fast moving objects in the universe.’
The main spacecraft they used to travel between the stars - named Endurance - seemed pretty realistic according to the experts.
But one thing that seemed implausible was the simplicity with which the spacecraft landed on and took off from planets.
Lee Billings: 'Endurance seems quite plausible, in terms of artificial gravity spinning around to give you that force that prevents bones from decaying in microgravity.
'The main thing that seemed unrealistic was whatever propulsion they had, to escape the extreme gravity wells of a planet that caused men to age a decade in an hour.
'I sure wish our Nasa had some of that fuel because we could go places a lot faster!’
Mat Kaplan: 'Gene Rodenberry said he created transporters for Star Trek because he didn't want to waste time getting to the surface and back.
'I think quite possibly a little bit of that was going on here as well, but it's certainly forgivable for telling a great story.'
