[Kamog]

I was thinking about ring worlds, and it occured to me that artificial gravity created by rotation would not work the same way as natural gravity generated from mass. If you have a spinning cylinder, the centrifugal force causes objects sitting on the inside walls to experience an outward force, causing them to stay against the walls, right? But imagine the spinning cylinder, and placing a ball inside the cylinder, close to the wall, but not touching. It's not clear to me that the ball would be attracted to the wall. It seems to me that the ball would not experience any force towards the wall at all; it would just sit there.

Imagine standing in a circular room, with curved walls in the shape of a cylinder, and the walls were turning but the floor is stationary. It doesn't matter if the walls are turning really fast, you'll just stand there and you won't be pulled towards the walls. Now, if you were leaning against the wall, suddenly you'll be pulled against the wall.

So what would happen if you lived on a ring world, and you jumped up? Would you fall back down?
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...thinking...
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OK, yes, you would fall down, because before jumping, you were rotating with the same velocity as the rest of the ring world. When you jumped up, you still retain that instantaneous velocity (speed and direction) that you started with, plus a small vertical component added from the jump. Now, whereas the ring is constantly changing velocity (even if it's rotating at a constant speed, the angular direction of the movement is constantly changing), while you are in the air, you still retain the same instantaneous velocity you started out with as your feet left the ground, the velocity at the same speed in a straight line. Because the ground is curved and rotating, and you're moving in a straight line tangent to the point where you jumped from, you will hit the ground - a straight line intersecting an arc - so it's just as if you've fallen back down.