A Space-Gravity Conundrum
A little Backstory…
For April Fool’s Day this year, Swungover became “David Bowie’s Guide to Space-Gravity,” and allowed me to ask a question I’ve had for awhile to our awesome math-science community. Feel free to add your two cents in the comments section.
Over the last year, I’ve asked this question to a few very intelligent people, including rocket scientists, and have gotten different answers, so I was interested to see if there was a general agreement of one. During one of the conversations, I was making a point and somehow found myself using the words “space-gravity,” which cracked myself up and several others. We almost immediately agreed it was the kind of gravity David Bowie would specialize in if he were a mastermind physicist. Hence, the title. (Aside from the fact that we here at Swungover love David Bowie and would be honored to take over his physics blog.) Also note: I’m not the best at explaining all the information physicists need to have in order to answer it. So, I think I’ll go back to writing about swing.
Here’s the post:
A Space-Gravity Conundrum
Hello Cosmonauts. I’m currently busy finishing up my new theory of quasar periodicity and just need to finish laying down the vocal tracks for it. Still, though, it’s gonna be a pretty alligator cookie-crumble space-race, man. So I’m handing over the column to fellow blogger Bobby White of Swungover, who had a bit of a physic puzzle for you die-hard Space-Gravity scientists. — d.b. (phd)
Hi! My name’s Bobby White, and I’m honored to be presenting one of Dr. Bowie’s weekly puzzles. When I’m not listening to Doctor Bowie’s earlier works and studying Literary Physics (a special branch of physics that deals with measuring space-time in literary worlds, especially Beckett) I am a swing dance instructor. And so, I love to think about simple physics.
I am also a bit of a sci-fi buff, and one day was thinking about 2001: A Space Odyssey and had a question that I, being a Literary Physicist and not a Reality Physicist, could not come up with an answer to. I also asked a few rocket scientist friends the question, and they couldn’t agree on an answer (I really did). So, I began thinking to myself, “Where can I find a large group of math-science people whom I could ask?” Well, the swing dance community, of course, and Dr. Bowie’s revered online scientific journal here. So, here’s the puzzle:
RIDDLE ME THIS: In the film 2001, there is a space ship that creates artificial gravity by rotating a cylindrical hull. Because of centripetal effect, people would be pushed against the hull, giving it a fake gravity. Now, we know that such a thing is feasible, except that in reality, the hull would have to be more than two miles in diameter to make the artificial gravity safe for humans.
But we don’t actually need that for today’s question, which is more theoretically based. Let’s assume, measurement-wise, that the ship in 2001 is possible — that the center the ship orbits around is only ten or so feet above the astronaut’s heads. Now, let’s say a man standig on the “ground” in the spaceship tosses a ball towards the center (the space directly above his head).
WHAT COURSE WILL THE BALL TAKE? WHAT WILL HAPPEN TO THE BALL?
NEW! The Shana Challenge:
“Now an exercise for the reader: all of these explanations involve a static coordinate system with the spaceship rotating around one axis. But what if the coordinate system stayed with the astronaut. In other words: what is the path of the ball from the astronaut’s point of view?” –Shana Worel
Also, if you were to run on this spaceship, as Dave does in the film, what would happen in a real life situation? Because, when you technically run, both feet are off the ground at some point. Would that alter running? How?
UPDATED EXPLANATION (10:34 a.m.): In a real life situation like this, it’s not gravity, but centripetal(?) inertia giving the effect of gravity. In the film, because it’s filmed on earth, and the 1960s didn’t have the budget to make a space station (silly 1960s) to film it in, it appears to be real gravity, just always pushing straight away from the center of the craft. If you’d like to chose one or the other to base your answer on, I’m cool with that.
Also, there has been some questions raised about whether you’re inside the space craft, or outside of it, looking in, and possibly dying of suffocation and struggling to hold onto consciousness.
I find the answer to any of these interesting, just please note which one you’re answering in the comments section.
Please use the comments section below for your answers, or asserting if someone has gotten it right, in your opinion.