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[Ringworld/general] Questions about gravity on a ring construct/Dyson sphere.

So I'm trying to wrap my head around this, maybe somebody could help.

A ring construct, like in Larry Niven's Ringworld series uses inertia/centrifugal force from it's spin to simulate gravity. Like God spun a coin on a table. So would it then have no gravity at it's (for lack of a better term) north and south poles? And would "gravity" taper off the further north/south you go? Why isn't everything on the surface drawn antispinward by the acceleration?

Second does the same centrifugal force apply inside a sphere as in a ring? Does the shape affect it somehow?

Lastly: How would you navigate the surface? Like normal north, south, east, west doesn't apply right?  How would you tell what direction is what and what would you call them? IIRC In the books he uses spinward and antispinward for east and west equivalents but how would you perceive which is which from on the surface?
gpt
> A ring construct, like in Larry Niven's Ringworld series uses inertia/centrifugal force from it's spin to simulate gravity. Like God spun a coin on a table. So would it then have no gravity at it's (for lack of a better term) north and south poles? And would "gravity" taper off the further north/south you go? Why isn't everything on the surface drawn antispinward by the acceleration?

Incorrect, it spins like a car tire or bicycle wheel to avoid precisely the problem you are describing.

Once it is in motion, there is no horizontal acceleration. Just momentum, which is not noticeable in reference frames relative to the surface. (As a small note, you can throw objects in such a way as to observe Coriolis effects, though you probably won't notice on anything as large as Ringworld unless you're flying an aircraft, or starship, or launching artillery.)

> Second does the same centrifugal force apply inside a sphere as in a ring? Does the shape affect it somehow?

Yes, it's called a Dyson Sphere. That would give you less gravity towards the poles, but significantly more surface area to work with. Also, gravity angles outwards the further you are from the equator, so you'll want to build terraces into the design. Because there isn't much motion at the poles, they make for good docking ports.

> Lastly: How would you navigate the surface? Like normal north, south, east, west doesn't apply right? How would you tell what direction is what and what would you call them? IIRC In the books he uses spinward and antispinward for east and west equivalents but how would you perceive which is which from on the surface?

Yeah, spinward and antispinward make sense and are easy to observe. Then you just get to quibble about which of the other two directions you want to call north and whether you should invert it relative to what it would be on Earth because you're facing inwards instead of outwards.

Personally I'd use the right-hand rule. We spin counter-clockwise from one of the two possible reference frames *gestures with curled fingers*, so north is *points with thumb* that-a-way.