Articles like these come out a couple times a year and they are always fascinating and engaging, check out these Common Misconceptions about Space below:
Space is a difficult concept to represent on film, and not just because of floating hair and upside-down camera angles. The concept of space, a low- or no-gravity environment with no atmosphere and all sorts of foreign dangers, is difficult to portray accurately and still complete an engaging story. Still, some of cinema’s most beloved “facts” have wormed their way into the popular understanding of space. This must be brought to a swift and merciless end.
Sound in space
On Earth, in an atmosphere, there is a fluid medium physically connecting you to every other object around you; push some of that fluid around by moving and the other objects will feel the effects in some small way. Evolution eventually created a way to collect and interpret these fluid vibrations, creating ear physiology to do complex shockwave-analysis and derive useful info about the world. This is essentially the same idea as certain fish species, which detect shockwaves in water through nodules on their skin.
In space, however, there is no atmosphere, no fluid to carry shockwaves, and as a result there is no sound. Space is a uniquely alien place in this way; you don’t just miss out on the Pchew pchew! sounds of laser guns, but the sound of the space shuttle going by. The movies have rendered countless bassy space explosions for us over the years, but it’s the handicap in basic spatial awareness that film most misrepresents in space.
You instantly freeze in space
This one again comes down to kinetics. Yes, space is theoretically very cold, but heat is only transferred through the physical interaction of particles; with no particles around to soak up your body heat, space is actually remarkably slow in cooling you to its temperature. Though much of it was eye-roll-worthy from a scientific perspective, the movie Sunshine had a fairly well-done scene in which the characters are exposed to naked vacuum for several seconds and experience only mild frost-bite.
Given what we know about the human body’s reaction to a full vacuum, this might even have been overly dramatizing the effects of such short term exposure. In a vacuum you mostly need to worry about breaching your lungs (do not try to hold your breath!) and eventually the nitrogen in your blood, uh, leaving. It won’t be a pretty process by any means — but you won’t be frozen solid until long after it happens.
Space allows infinite speed over time
This one might not be such a misconception as it is an unspoken assumption: without the drag of air or the pull of gravity, steadily accelerating objects can achieve near-infinite speeds. Most people probably know that this is limited at the extreme upper end by relativity, and the difficulty of approaching the speed of light, but even before that point speed is problematic.
While NASA sees great potential for slow and steady propulsion systems like ion thrusters, final speed is still largely limited by the fuel source, which remains a major limiting factor for NASA. When accelerating in a direction, astronomers always have to accommodate an eventual slow-down at the destination, which will take almost as long as the acceleration itself (hopefully a bit less, thanks to the gravity of our target world).
There are fires and explosions in space
Fire is not an object, it’s a reaction: the combustion of gasses in air. Without air to release its energy as light and heat, fire fundamentally cannot exist. In space, of course, we have a serious air shortage, and so every movie you’ve ever seen with exploding space-ships is wrong. Actually, a short fire or explosion could be realistic, fed by the air still trapped inside a pressurized ship. In an instant, though, this air would be either used up or sucked out, and the fire promptly smothered.
Outward force from the explosion would cause hull breaches which let air escape rapidly, and the quick drop in pressure causes the hull to crumple inward, and in extreme cases actually implode. Non-pressurized objects could be made to explode in the more classical sense of destructive outward expansion, but this still would not include any component of fire. In a rocket engine, which obviously must create fire in space, a source of oxygen must be brought along in the tank since there’s none in the atmosphere to ignite.
That stupid pen-pencil thing
All narratives of government inefficiency aside, it’s incredible that people could be tricked into believing the following oft-repeated canard: while NASA spent millions and years developing a pressurized space pen, the Soviets just used a pencil. Har har, am I right? You know, because the Soviet way of doing things turned out to be a model of efficiency and financial prudence… Regardless, this obvious falsehood has a less obvious explanation, in that it goes back to the special requirements of living in space.
While on Earth the tiny shavings of graphite left behind by a pencil stick to paper or fall to the ground, in orbit they will float up to get sucked into the air recycling systems. To avoid breathing in graphite, and munging up the air filters, NASA developed a pen. And, as you ought to have expected from the agency that put a man on the Moon, it really didn’t cost all that much, either.
You go Total Recall on the surface of Mars
This one is actually a bit more realistic than the above, since Marshas a very thin atmosphere. The effects of the Martian surface would be roughly similar to those of actual space, cooling you more effectively but popping you less effectively. Over time you’ll have problems like the bends, where nitrogen in your blood boils out just like in a vacuum, but it will happen slightly more slowly.
Also in Total Recall is a classically Paul Verhoven sound effect to go with the characters’ labored breathing, while in reality Mars’ atmosphere is almost certainly too thin for a human to re-inflate their lungs once they’d been emptied.
Astronauts zip around on jets like it’s nothing
While the compressed-air jets that allow astronauts some maneuverability are certainly real, they are not generally used as portrayed in film. In practice, the jets are viewed mostly as a last resort, a safety item included for use only if an astronaut should find themselves untethered from their craft and floating away from safety. Also, without large dedicated backpacks that make the suits far less useful, you can’t carry enough compressed material to propel you very far at all.
In a couple of historical cases these astronaut propulsion units were used as the main mode of transport to complete a mission, but this is unnecessarily dangerous. Astronauts will almost always favor a slower, fixed path from A to B, rather than leaping across a gap in the ship and trusting their jets to direct them safely to the other side; if nothing else, space ships aren’t designed to have 200-pound Air Force pilots slamming into them from all directions.
Asteroid belts are hard to fly through
Now, I don’t want to get mired in trying to disprove sci-fi actions scenes here, but Star Wars has led to a very common misconception about asteroid belts. Yes, they are very densely populated by the standards of space, but that still means you’ll have half kilometer-sized rocks flying hundreds of thousands of kilometers apart.
If you took the global network of commercial flights and compressed it down so they were all flying through a section of airspace about the size of Detroit, then you might get a situation as dangerous as the Star Wars asteroid scene. Now, the rubble-field created after the destruction of Alderaan — that might have a chance of being watch-your-six crowded for pilots. Regular asteroid fields, though? Not a chance.
There is a “dark side of the moon”
This one speaks to mankind’s hubris more than anything else, the cat-like level of self-awareness that tells you that if you can’t see it, it probably doesn’t exist. A process call tidal locking limits rotation of the Moon through complex gravitational interactions, and results in us always seeing the same portion of Luna’s surface. However, the fact that we never see the far side doesn’t imply that it never receives sunlight; as the Earth orbits the Sun and the Moon orbits the Earth, every part of the Moon is bathed in light.
If nothing else, think about a solar eclipse; having the Moon between the Sun and the Earth ought to make it obvious that the far side of the moon really does receive sunlight, right?
Astronauts are in “zero-g”
We talk about the medical impacts of living in “zero gravity,” but the reality is that no human has ever truly been in zero-g — remember that nobody has ever been further out than the Moon, and the Moon is held in orbit by gravity. Rather, astronauts really experience reduced gravity due to their distance from the Earth, and zero effective gravity due to freefall.
By traveling at a speed and angle required to stay in orbit for long periods of time, they almost literally live their lives on the downward slope of a roller-coaster. Your hair and arms float up while you plunge down — and if that plunge lasted forever, you might even find a way to get used to it.
Space is hard to do right
So while we might be able to forgive some cinematic sound-effects for explosions, and even look past some inaccuracies with gravity, there are plenty of ways that cinema could improve its accuracy on space without rendering the movie-making process more difficult. At the very least we could see some reduction in misunderstandings of space, which will be important as NASA prepares us to become an interplanetary species.