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

Items in the ship would be rotating at the same speed as the ship. So, jumping up in the air would basically seem “normal,” to you. It’s the same thing if you were standing in the back of a box truck traveling down the highway at 60 MPH. If you jumped straight up in the air, you would land right back where you started, not get thrown into the back door of the truck. It’s because the truck, and you, and all the air inside the truck, are all traveling at 60 MPH.

The same effect applies if you’re standing at the Earth’s equator and jump straight up in the air. The circumference of the Earth is just under 25,000 miles, and it rotates once every 24 hours. That means that, at the equator, you are already traveling about *one thousand miles per hour*. Yet, if you jump straight up in the air, you’ll land right back where you started, because both the Earth *and* you were traveling at the same 1,000 MP when you jumped.