Putting the science in fiction - Dan Koboldt, Chuck Wendig 2018

Misconceptions about space
Sometimes, it really is rocket science

By Jamie Krakover

It’s fun to think about “what-ifs.” And there are a lot of really cool possibilities when it comes to space travel. Unfortunately, a lot of the awesome things we see in science fiction movies and even books are less than realistic. That’s not to say you can’t stretch the truth and explore options, but if you want your writing to be believable there are some concepts about space travel that will help build a foundational understanding.

How do we as writers decipher reality from Hollywood? How do we create fiction that could be realistic and that is an extension of our world without making it overdramatized and fake? We research. In an effort to put my rocket science to good use and help my fellow writers, here are nine common misconceptions about space travel.

Myth #1: People and objects in space experience zero gravity

In space we call it zero gravity, but gravity isn’t really zero. Gravity is the pull one object has on another. It’s why things fall to the ground when you drop them, because the Earth has a gravitational pull. But when you’re in space, you are actually in free fall. This is why it gives the appearance of weightless, or “zero,” gravity. In space you are outside the gravitational pull of another body. Because of this you will keep free falling because there is nothing to pull you toward it. In other words, you are falling in an infinite hole because there is no bottom to hit. So while zero gravity is slang for what space travelers experience, they really are just free falling continuously with no end.

Myth #2: There are formal directions in space

In space, up, down, left, right, etc., are all relative to your current position or the position of another object. It’s easy to get disoriented because there is no north or south, forward or backward—it’s just a vast expanse. Without other objects to orient against, it would be hard for someone in space to figure out which way is up. Literally. Because “up” as we know it doesn’t really exist. The minute a person in space flips over or reorients, “up” is a completely different direction.

This is one reason why the quote “The enemy’s gate is down” from Orson Scott Card’s Ender’s Game is so famous. Because in space, “down” is relative to what direction you are facing. Orienting in space isn’t easy. There’s no floor or ceiling, and that’s a difficult thing for the brain to wrap itself around. But Ender identifying the enemy’s gate as down, helped him orient within the battle room where they were in a near weightless environment with no frame of reference. Therefore, directions in space are usually given in reference to other objects to help the human mind wrap itself around which way is designated as up.

Myth #3: Flying in space is like flying on earth

Unfortunately, it’s not even close. It’s not like cruising around underwater, either. Sure astronauts train in the water, but that is mainly to help simulate the feeling of “weightlessness.” Astronauts often build and maneuver heavy objects in space, so training in water helps simulate a lighter load. That said, maneuvering in space is extremely difficult. There’s no friction.

When Isaac Newton said an object in motion stays in motion until an external force is applied, he meant when you push on something it will keep going forever until something else stops it. On Earth, a lot of times that something is friction (or a car or a wall or another person). In space, there are very few things to stop objects in motion. If you move something it will presumably go in the direction pushed, forever, unless it hits something else or enters into the gravitational pull of another object (see Myth #1). In which case, the object will then take on a new direction and continue on in that direction until affected by something else.

Even worse, you can’t just wave your arms in space like you can in water and move around. Space is a vacuum. There’s no air around you to displace and therefore move yourself. Without some kind of jet pack to propel you, you would be stuck floating in the middle of nowhere. (Or speeding through space in whatever direction you happened to be going.)

Where it gets tricky is when you add in the fact that things can go (for lack of better words) up and down, left and right, and front and back. But you can also spin around those directions in what’s called yaw, pitch, and roll.

When you combine those directions in different combinations, there are a lot of different ways an object can move (as described by the six degrees of freedom). It can pitch and go down, it can roll and go forward, it could do everything at once, etc.

If you have an object spinning toward a planet through space, it’s pretty hard to get it to stop. If it hits something else, it’s likely to be sent spinning off in a completely different direction forever, or until it encounters another object or gravitational pull.

Search for gyroscopically stabilized CD player in microgravity on YouTube to see a great video that shows how difficult it is to stabilize a spinning object in space.

Myth #4: Stuff “blows up” in space

Science fiction space battles are the best. Watching spaceships blow up is really cool. Unfortunately it’s extremely unrealistic. Again, space is a vacuum. There’s no air, which means there’s no oxygen in space. Without oxygen, you can’t have fire. And without fire there can be no explosions. Sad, but true.

The corollary to this is, if you have an oxygen-rich environment like a spacecraft, you can have fire inside portions of the craft or in the engines if it has an oxidizer (liquid oxygen).

Myth #5: How people die in space

The last thing a person would want to do in space without a pressurized suit is hold his breath. You’d actually want to exhale air so the vacuum of space didn’t pull the oxygen out and cause your lungs to rupture. The remaining oxygen in the human body would cause it to bloat. After bloating, a person would likely lose consciousness. From that point, the person would probably die from hypoxia or an embolism because the body is strong enough to keep the bloating contained.

People also can’t freeze in space. Although space is extremely cold, in a vacuum, heat transfer works very differently. Your body would maintain its heat and keep heating itself. In fact, you’d probably overheat before you froze. That said, your blood will not boil in space. While space is cold enough for liquids to boil, and lower pressure means a lower boiling point, your blood has no direct exposure to space. Therefore your blood won’t boil. It’s protected by your skin and the rest of your body.

Lastly, people don’t run out of oxygen in space. Well they do, but that’s not what kills them. If a person was in a room with no oxygen source, she would die from the excess of carbon dioxide exhaled. Since blood rich in carbon dioxide is poisonous to humans, that is what would kill someone, not the lack of oxygen.

Myth #6: There’s sound in space

Sound needs something to compress or vibrate against in order to create waves, which is what we hear. In space there’s no air; it’s a vacuum. Therefore, there’s nothing for the vibrations to compress against. Which means space is a sad and quiet place. And if you could have awesome space explosions (which you can’t: see Myth #4), you wouldn’t be able to hear them.

Myth #7: Creating a gravity environment in space is easy

They don’t call it rocket science for nothing. There isn’t a magic button you can push on a spaceship that will suddenly conjure gravity. The way to create gravity in space is to create a force that will push objects in a certain direction. On Earth, that direction is toward the floor or the ground. On a spaceship, that’s a little harder to simulate. You have to do it using rotation.

If you spin a bucket of water in a circle upside down at the right speed, the water will be pressed against the bucket and won’t spill regardless of whether the bucket is right side up or upside down. Using this same theory, you can spin a spacecraft at the right speed such that the people and the objects inside are pressed against the outer walls of the craft. This creates a gravitational environment.

Where things get tricky is how you actually go about doing this. There are many arguments as to whether a giant spinning ring or a spinning tethered craft would work better. Both have pros and cons. Regardless of which option you choose, it’s an expensive endeavor to simulate gravity. Making something that large spin is difficult. There are a lot of logistics that go into how you get something to spin at the right speed. Too slow and you don’t get enough gravity. Too fast and you make people sick.

Once you get a craft spinning, it should sustain itself (see Myth #3). But if for some reason you have to stop the spin or you want to do more than orbit (i.e., travel to other planets), things get tricky. It’s hard to make a ship go the direction you want it to when it’s spinning. (Go watch the video mentioned in Myth #3 again.)

Myth #8: The sun is on fire

It’s not really on fire, but it is really warm, blazing hot in fact! In addition, the Sun can also be quite dangerous in space. Radiation is a very real concern. On Earth, the atmosphere helps protect people from the Sun’s radiation to some extent. However, in space there is no atmosphere, so space travelers are at a much higher risk of receiving higher doses of radiation. Protecting against radiation, especially large galactic cosmic radiation events, requires quite a bit of shielding. Radiation shielding can be one of the heavier parts of a spacecraft. If a spacecraft doesn’t have enough shielding, a solar flare or event could wipe out an entire crew.

Myth #9: A light year is a measurement of time

Sure it has the word year in it, but a light year is actually a measurement of distance used by astronomers to try and reduce the use of large numbers in their calculations. One light year is about 5.9 × 10^¹² ft, which is a 59 followed by eleven zeroes. A HUGE number. The Sun is 92,960,000 miles from the Earth, or 0.0000158 light years. Unfortunately, that’s a rather ugly number as well. But when you start talking about other star systems that are tens of hundreds or even thousands of light years away, things look a little cleaner when you can say something is one hundred light years away.

And that wraps up nine misconceptions about space. This is by no means an exhaustive list of things people don’t quite get right about space travel, but hopefully it helps put a few things in this vast universe in perspective. After all, they wouldn’t call it rocket science if it was easy.