Are you stupid about science and things? I am! I can barely do math. So after several years of study, I can tell you, fellow dingbat, what you need to know about space before seeing terrifying and wonderful space movie Gravity. It really is as good as everyone says. Here's one tip about seeing this film: when you can, keep your eyes on the horizon line. I was worried I was gonna heave a little, in part from visual orientation problems but also from anxiety. Throwing up in a movie theater is the third worst place to throw up. The second worst is the subway. We'll get to the absolute worst in a minute.
How far is space?
Space starts about 62 miles above the ocean! Mostly. Kinda. Technically an astronaut is anyone who's been higher than 50 miles above sea level. The International Space Station is about 260 miles "up." This map of where it is makes me feel like barfing. Anyway, New York City to Boston is 215 miles. So near space isn't very far. The problem is… it just keeps going. Let's not think about that! Shh.
But you don't weigh anything in space, why are things so difficult?
Yeah this is the worst. Okay. So your weight is just a measure of how all of you is being pushed against the ground by gravity. But that's not really how "much" of you there is. Weight is kind of bullshit. Mass is where it's at. When you are weightless, you still are the same thing, right? You're the same in space, in the ocean, on land. So even if you are flying around without gravity—which is to say, weightless—you still are the same thing. This is how we are all going to get hurt a lot when we live in space. We'll be like "wheeee" as we fly around and whatnot but guess what? Collisions are about mass and speed. And when you slam yourself into a bulkhead, it doesn't matter that you "weigh" nothing because you, um, still exist as an object of mass. Get it? In fact, it's kind of worse, because you don't have the air to slow you down. Airplanes fly because air is thick; airplanes can also slow down because air is thick. Without thick air, you just keep going. Here have a cookie.
What is that "equal and opposite reactions" thing from that guy with the ideas?
I mean this couldn't be much clearer, but I know, science. So you know when you fire a gun? The "recoil" from the gun launching a bullet pushes back in the opposite direction—down your arm. The handy thing about guns is that you're holding them when you fire them, so the shove it makes towards you is braced and absorbed, mostly, through your body and then to the ground. In space you can't do any of that triangulation, basically because you're not being pushed down to the ground by the horribleness of our terrifyingly spinning planet. Equal. And opposite.
What's the worse thing that can happen in space?
Pretty much every science fiction writer agrees that barfing in your helmet is the worst thing that can happen in space. ENJOY!