In sci-fi with “spinning” ships to make gravity, how does someone drop something and it lands at their feet?

Question

This fogs my brain every time I watch one of these shows and I feel like maybe I’m completely misunderstanding the physics.

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You’re in a “ring” ship. The ring spins. You’re standing on the inside of the ring so it takes you along with it, and the force created “pins” you to the floor, like a carnival ride. Ok, fine.

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But that’s not gravity, and it’s not “down”. Gravity is acceleration, so what keeps the acceleration going in the ring ship is that you are constantly changing your angular momentum because you’re going in a circle. Ok, so when you let go of something, like a cup or a book, wouldn’t it go flying towards the floor at an angle? If you jumped wouldn’t you look like you rotated a little before you hit the ground, because you’d, for that moment, be continuing the momentum of your angular velocity from when you left the floor and the room would continue on it’s new, ever turning, course?

Wouldn’t it kind of feel like walking “uphill” one direction and “downhill” the other, with things sliding about as the room “changed” direction constantly?

Am I just COMPLETELY missing this idea and creating a cause and effect that doesn’t exist?

In: Physics

Answer 1

When you hold something, it moves with you. When you let it go, it is free to move in the direction it was moving just the moment you let it go. When ship spins, it constantly changes the direction of travel of everything that is held by the inner surface, by the friction against inner surface, or is held by anyone on inner surface. So when you let go of something, it doesn’t just “fall”, it simply keeps going in the direction it was already moving, but the floor of the ship is in the way.

Note, the object wouldn’t actually fall straight down, it follows a curve path due to the difference of velocity between the ship inner surface and the object, because the object you’re holding would be closer to the center of the ship (called the Coriolis effect), so the smaller the ship, the more curved the fall path is. On much smaller ships, the dropped object won’t land at your feet, but fall somewhat sideways.