You’ve been tricked, and by science! Misconceptions about space are ubiquitous, and almost no one can escape them. Well, no one except for scientists. We are here to set you straight on all those little white science lies that Hollywood has popularized so you can go out in the world knowing the truth. Though Hollywood has gotten a lot wrong about space over the years, you can find consolation that only a few have really stuck around as serious misconceptions. Some have been spread in science fiction movies like Avatar or Star Wars, and others are just ideas that have stuck around as old wives’ tales and folk stories from your grandparents. However, knowing the truth will help you understand the future of space travel and what those movies should look like. Read this article to discover the most pervasive misbeliefs about space that have been spread, and how to convince your friends and family of the scientific truths.
Unsplash by NASA
Astronauts float in space.
Astronauts don’t actually float. When astronauts are in space, they are actually in a state of freefall according to NASA. That’s right. While the astronauts feel and seem weightless, they are actually just hurtling towards the Earth at terrifying speeds. You may be wondering how this could be, since they obviously don’t just go straight down to their deaths. That's because they are in orbit, hurtling around the Earth instead of directly towards it. In reality, the distance from the International Space Station isn’t actually far enough to reduce the force of gravity from the Earth significantly. The microgravity that ISS astronauts experience really is just the effect of being in orbit around the Earth.
Unsplash by Holger Link
The Sun is yellow.
The sun has a huge spectrum of colors, which all together create a white colored light. This is easily demonstrated when we see a rainbow or a prism that breaks the light into all the different colors. In general, we see the Sun from Earth as yellow due to our atmosphere filtering out the cooler colors in the spectrum. During sunset, this is especially strong due to the angles of viewing and the additional atmosphere the rays of light have to pass through to get to your eyes. This means even more cooler colors are filtered out, making the Sun appear orange or red. If you ever experience a smoky day during the summer, the Sun will appear red due to the additional smoke particles in the air blocking rays. Fun fact: on Mars, the Sun appears white during the day and blue during sunrise and sunset. Mars has about one percent of the atmospheric density that Earth has, explaining the closer to true color visual of the Sun.
Unsplash by NASA
If you were exposed in space, your blood would boil.
Your blood would not boil in the vacuum of space. This misconception owes its dues to the lack of pressure in space. While it is true that the lack of atmospheric pressure would rapidly evaporate an open container of water, your body is actually a closed pressure system. Like a closed piston system that pushes water the opposite direction of gravity, your body is mostly a closed system that will retain what is inside of it, and the lack of atmospheric pressure won’t do much to damage your system. That said, you may want to keep your mouth, nose, and eyes closed if you ever find yourself in the vacuum of space. The saliva in your mouth and the fluids that keep your eyes moist would boil off very quickly, making your impending demise very uncomfortable.
Unsplash by NASA
If you were exposed in space, you would freeze.
Your body would retain your body heat in space. Eventually, since you wouldn’t be able to vent off excess heat, you would get extremely uncomfortable. That said, the timing for this discomfort is much longer than the 15 seconds it would take for you to run out of oxygen and lose consciousness, so you’d never have to actually worry about getting too hot. 15 seconds you say? You can hold your breath for longer than that, right? Well, not in space you can’t. Your breathing airway is NOT a closed system, and any air you held in your lungs would rapidly expand in the vacuum of space, rupturing your lungs and killing you in what I’m sure would feel like a slow death.
Unsplash by mana5280
Comet tails follow behind the comet’s path.
The tails on a comet do not follow behind the comet’s path. The tail we see in telescopes, or in the case of the popular 2020 Comet NEOWISE with our naked eye, is made from melted ice and debris loosened by the melted ice of the comet. However, the source of heat for the melting is not from the movement of the comet. It’s actually from the main source of radiation in our solar system, the Sun! This means that any comet tails are essentially pointing direction away from the Sun, not directly away from the direction the comet is moving.
Unsplash by Greg Rakozy
A light-year is a measure of time.
Light-years are actually measurements of distance. By definition, a light-year is the distance that light travels in a year. This is a universal standard because light travels at the same speed, about 300 thousand kilometers per second. The distance that light managed to travel in a year is enormous; it is about 9.4 trillion kilometers or 5.9 trillion miles. For some perspective, it takes light from the Sun to reach Earth in 8.3 minutes. However, it takes light from the next nearest star, Alpha Centauri, to reach Earth in 4.4 light years. And for an even bigger picture, the Milky Way galaxy at its widest measures around 100 thousand light-years.
Overall, most people have misconceptions not because they don’t care, but rather, because they do. Figuring out this physics and space stuff isn’t easy, and not everyone can have a PhD in astrophysics. Learning about science, even if you don't always get it right, is demonstrating an interest and a willingness to learn, and that’s pretty out of this world.
