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This is a follow up to a previous question that I thought should be a new question instead of just discussing in the comments of that one.

This is an idea for a space station on the surface of Eris (but could work on other celestial bodies), using rotating rings to simulate gravity. The idea is that these rings would sit horizontally on the surface of the dwarf planet much like you would expect in space. Instead of the floor of the rings being the inner flat edge, the rings would be slanted forming a sort of downward cone shape. You could imagine it much like how a freeway or racetrack is banked around turns.

Ideally the rotation would produce centrifugal force pulling the occupants towards the edge to simulate gravity, however, the slant of the rings would counteract the existing low gravity of Eris which is roughly 1/12 of Earth's. The closest real world comparison I could think of would be the Gravitron amusement park ride, but on a massive scale.

The previous determined that the appropriate angle of the ring's slant would be roughly 10 degrees from the vertical plane, making the floor of the rings nearly perpendicular to the surface of Eris, but not quite. From what I understood, the ring size was negligible for the slant angle, but important for calculating the appropriate angular velocity to produce simulated gravity.

Would a ring station of this design be likely to cause issues with balance or vertigo if an occupant moved or turned too quickly?

Originally I had also been working with the idea that the ring might be fairly large, with a diameter of 10 km and height (width?) of 100 m. I am currently playing with the idea of multiple, much smaller rings measuring 2-3 km in diameter and width of 50 m. I would appreciate an answer for either case.

As far as I understand, it is believed that such issues would only occur in very small rings (meaning only a dozen meters or so in diameter). With larger rings it shouldn't be an issue except when quickly transferring from one ring to another. These of course are all theories though, and none of them take into account the idea of an external source of gravity.

As a clarification, I actually want the vertigo issues to occur as it will help propel certain aspects of my story. I just don't want to write that my main character spinning around quickly during a fight caused them to get slightly dizzy if realistically they wouldn't.

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  • $\begingroup$ You may check out SpinCalc. It does not account for natural gravity, so just set Centripetal Acceleration to the number that you need (less than 1g). $\endgroup$ – Alexander Dec 19 '18 at 21:26
  • $\begingroup$ First step should probably be calculating difference of gravity between head and feet. See this answer for equations. You want this difference small, because in your case it will also mean change in angle of perceived gravity. $\endgroup$ – Mołot Dec 19 '18 at 22:00
  • $\begingroup$ A question where centrifugal and coriolis forces aren’t imaginary artefacts. Hooray! $\endgroup$ – Joe Bloggs Dec 20 '18 at 11:02
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The best data that I can find is that rotational rates exceeding 0.5 rad/s can potentially cause people to feel disoriented. Granted, this was found through experiments in centrifuges on Earth, which isn't quite the same thing as you're asking for, but we haven't been able to study people in a centrifuge within a shallower gravity well, so I'll just use those figures.

So, because you want to produce one gee of apparent gravity on a body with surface gravity of 0.836 g, this means that you want the centrifugal forces to be 0.996 g.

If you plug in this limit of 1 radian per second into the radial acceleration formula, $a = \omega^2 R$, then you find that the minimum radius is 39 meters, which is likely a lot smaller than you're going for.

As far as moving from one spinning ring to another, there haven't been any studies done on that (at least, none that I know of). However, my supposition (entirely an educated guess, so take it with a grain of salt) is that, while it might be disorienting to a person who grew up in a place like Earth where that doesn't happen, people who grew up there would, in my opinion, have brains that get used to it and don't get disoriented. But, once again, this is all speculation as I'm pretty sure that the sum total of human knowledge for this instance is zero.

However, you have a much easier method of getting your protagonist dizzy. A concussion can cause dizziness, and those are brought on by head trauma, which fights can certainly bring.

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The occupants would feel the Coriolis effect, which could cause motion sickness. Also, it is suggested, those who adapted to this kind of environment could tell easily tell direction, spinward or anti-spinward by moving their head.

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