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
You’re right. It’s called the Coriolis effect! Watch The Expanse, there’s a scene where someone pours a drink into a cup and the stream turns to the side.
No, your intuition is correct. In a rotating ring space station, a dropped object will not land at your feet. The object retains the “lateral” velocity it had at the radius you were holding it, which is less than the lateral velocity of the floor. So while it is falling, the floor (and your feet) moves sideways with respect to its path. To Your eyes, the falling path would be curved to the side.
Your next to last paragraph is also correct, in principal, but in practice I think the effect would be negligible. Your walking speed is much less than the speed of the ring, so the difference between walking one way vs the other would be tiny.
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.
>Wouldn’t it kind of feel like walking “uphill” one direction and “downhill” the other
I think it would feel uphill in both directions due to the visible curvature.
Yes, you are missing it completely.
The air is spinning and all the objects too.
If you drop something, it still carries the circular momentum to fall straight down.
When you drop something on a plane, does it fall towards the back of the plane?
Or does it fall straight down?
Well, same goes for the spinning gravity simulator.
I have [this Tom Scott video](https://www.youtube.com/watch?v=bJ_seXo-Enc) saved for just such a question. You are correct in your suspicions. A rotating ring can simulate gravity, but it will never be perfect. There would be weird artefacts like you describe, and, unless you’re acclimated to the shifting momentum, you’d be falling over a lot. The lab that he was recording from tests to see whether we really can get used to an environment like that. The physics inside that chamber gets trippy.
The earth is rotating very quickly. If you jump you fall straight down and don’t feel any rotation. If the ship were extremely large then you would not notice any difference between it and earth. However, if the ship is small, then near the center of the ship is rotating slowly and the outer edge of the ship is rotating faster. So for a ship that is not incredibly large then yes, you would get rotational effects as you go toward or away from the center of rotation. This is called the Coriolis Effect and actually does happen on earth too, we just generally don’t notice it because earth is so big.
The Coriolis effect is why hurricanes always spin counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. Since hurricanes are so large, the effect of the changing rotational speed away from the equator is not negligible. In a smaller ship, you would notice that same Coriolis effect just walking around. The only reason you don’t notice that effect on earth is because you, unlike a hurricane, are tiny compared to the earth so there is not any significant change is rotational speed as you walk around.
What you’re referring to is generally known as the Coriolis effect, and how noticeable it is ultimately relies on the size of the ship. If the spinning ring is relatively small, like the one shown in 2001 Space Odyssey for example, then it would be fairly easy to observe it in action, by throwing objects or running and jumping. If it was a huge ring, then it’s not like the effect would cease to exist but it would barely be noticeable, just like it exists on Earth which itself is spinning but is rarely noticeable.
I think one thing you’re missing, and most of these comments are missing, is the way the rooms/hallways/etc would be oriented. They are designed so that the spinning of the ship creates downward pull in whatever room you’re in.
What I think you’re missing is that if the ship is large enough to not create motion sickness and produce close to 1G then there will be a minimal difference in linear velocity in the 3 or 4 feet the object is falling. In the fraction of a second that it’s falling it would only move an inch or two.
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