Are regularly told that you’re being silly and pedantic when you point out gross violations of the laws of physics in movies, because ‘it’s just a movie’?

Well, you’re about to feel totally validated, because we are about to get real silly and pedantic. Hollywood can be pretty negligent about physics and astronomy, even in really good movies, but there are a few specific misconceptions that pop up again and again.

So let’s set the record straight on a few of these once and for all. Also, spoilers ahoy! All movies mentioned are listed in the description, so check to make sure you don’t want any of these movies spoiled before you keep watching!

One of the really common areas where movies take some creative liberties with science is with asteroids and comets. Like how the asteroid belt is commonly depicted as a dense minefield of death rocks, while the reality of the situation is much less exciting. Asteroids are typically 1-3 million kilometers apart; for comparison, the Death Star is about 160 kilometers in diameter.

So, you’re gonna be pretty safe. And speaking of safety, if you were to ask a screenwriter how prepared we are to handle any impactor, they would probably say “not at all, we’re all doomed”. In the cinematic masterpiece Armageddon, for instance, NASA detects an asteroid the size of Texas only 18 days before it’s going to kill us all, and then sends out Bruce Willis and his ragtag team of oil-rig roughnecks to blow the thing up.

I don’t know why Hollywood so vastly underestimates NASA’s ability to detect potentially dangerous impactors, because NASA would definitely have known about Texas In Space way in advance and had everything under control. NASA’s Center for Near-Earth Object Studies is constantly scanning the sky for space rocks trying to get too friendly with us, and they’re pretty good at it. They keep track of thousands of objects and assess the likelihood of any of them impacting us.

When they find an undiscovered near-earth object, they calculate its orbit and its potential as a threat; then, if it could be a problem, they add it to the set of known objects that are tracked and have their orbits periodically reviewed. Orbits are calculated out to 100 years, so we would know way in advance if an extinction-level collision were going to happen, which would give us enough time to plan to deflect or destroy the thing heading for us. It is true that sometimes we don’t detect objects that buzz close to Earth until they’re almost here, but the reason it takes us so long to spot them is that they’re so small they’re hard to detect.

And since they’re so small, they’re not really much of a threat. Definitely not an extinction-level threat. But I could talk about all the good things and bad things about Armageddon all day, so let’s move on to black holes.

In the Star Trek reboot, when Spock Prime and Nero are consumed by a black hole, it sends them back in time, whole and alive. But once you enter a black hole, you’re not getting spat out at any point. You’re getting spaghettified.

Seriously, that’s what astronomers call it. You start to get stretched and extruded like toothpaste through a tube, ripped down to your constituent atoms and subatomic particles. And then the particles that used to be you are stuck in there.

Forever. There are all kinds of other problems with the way black holes are portrayed in that movie. Like, it should’ve been impossible for Nero to create a black hole in the center of the planet Vulcan, and even if he had, there’s no way it would’ve been big enough to swallow the planet that quickly.

But he shouldn’t have lived long enough to try it in the first place. And finally, on the subject of space deaths, did you know that you won’t actually explode in space? Not even in the diminished atmospheric pressure of Mars!

So, awesome as it is, that scene in the original Total Recall is where Cohaagen is blown out of a building on Mars and balloons up as his eyeballs pop out, isn’t really plausible. Not that much of the movie is. It’s a common misconception that the difference in pressures inside your body and outside in space would equalize so quickly that your head would just pop, but actually, your body will keep everything in place, kind of like a pair of Spanx.

Your skin, muscles, and blood vessels have a lot of tension to them. They’ve got all kinds of nice, springy proteins in them, like collagen and fibrillin, and their cumulative tension provides enough force to keep your blood from evaporating and your eyes from popping out. And your head definitely won’t explode.

So that scene in 2001: A Space Odyssey where Dave has to break into his own spaceship from outside is actually pretty accurate! His head doesn’t blow up or anything; it’s just really windy for a second as the air rushes out of the escape hatch. As long as you keep your exposure to a vacuum under 10-15 seconds, you’ll be fine.

You probably won’t even lose consciousness. So that’s just a tiny sampling of some of the terrible science we see in movies. But that doesn’t mean you shouldn’t watch them.

Bad movies can still be super fun. Just don’t believe everything you see! Thanks for watching this episode of SciShow Space!

If you want more bad science, you should check out our videos on the main SciShow channel about just how impossible Sharknado would be.