[–] carasci 0 points 2 points (+2|-0) ago 

The short answer is "no." Spin-induced artificial gravity is dependent on the person spinning along with the cylinder/ring, with (as you noted) the centripetal force simulating the effects of gravity. Within such a person's frame of reference, they are stationary WRT the cylinder itself and moving with regards to the rest of the universe, but stopped from flying down into it by the upward force of the cylinder on their feet. If they are stationary WRT the rest of the universe, the cylinder is now rotating with regards to them - if we could magically drop them onto a point inside the body of the cylinder, they wouldn't "feel" any gravity at all.

In reality, though, things would work a little bit differently for one simple reason: they cylinder is probably full of air, which is rotating along with the cylinder. Thus, if you drop someone in near the center axis of the cylinder they won't feel much gravity or force, but once they're off the center axis the air will start to speed them up the same way being scraped along the floor would be (not as nastily though) and they'd start to be "pulled" towards the outside of the cylinder long before they synced up with it. Without running any numbers, my guess is that the overall outcome would be fairly situational (spin velocity, cylinder size etc), but it could potentially range from them slowly speeding up to match the cylinder while drifting floorwards and pretty much syncing neatly....to being promptly thrown into the floor as though they'd fallen from a significant height.


[–] snurfle [S] 0 points 0 points (+0|-0) ago 

Thank you.

That is sort of what I was thinking - air + friction = forced motion.

Some quick math says that a 250-foot diameter at 2 RPM (from the original article) has a tangential speed of 1570 feet per minute, about 18 MPH - in round numbers - So an 18 MPH sustained surface 'wind' would be pushing me toward the ground (if the air were stationary with respect to the ground,) essentially cancelling the Coriolis effect - I would hit the ground straight on at... hmmm. varying g makes this interesting. If my math is right, from axis to ground in appx 4 seconds, so about 44 mph... I would hit the ground fast enough to kill me, or at least seriously injure me.

Cool - Arthur C. Clarke was right. Can't believe it took me this long (35 years!) to figure this one out!

Thanks for the 'push' in the right direction. (I tried replying to another post, but voat wouldn't let me reply.)


[–] carasci 0 points 0 points (+0|-0) ago 

You're close, but it's a bit more complicated than that: you may have an 18MPH sustained wind at the surface, but this velocity will quickly decrease as you move towards the center axis of the cylinder. Moreover, the wind is always going to be tangent to the surface of the cylinder, and thus tangent to the circle around the center axis whose surface you're on. As soon as you start moving, the direction of the wind relative to you will effectively start changing, because you're slowly orbiting the cylinder. The acceleration is always "straight" in terms of accelerating you along the edge of the cylinder, just not towards it, though I'm not awake enough at the moment to actually figure out how the equations pan out in the end - it's one of those problems that ends up with a whole bunch of components but may largely cancel in the end.