Space station artifical gravity

[KontaktMan]

I guess. If you imagine two spheres one inside the other separated roller bearings one with a motor attached. Now spin the sphere(s) up to speed. You have 1 G at the equator and 0 G at the poles. If you then turn on the motor so it will make the inner sphere turn 1 revolution in 24 hours it would work. The trick here is that from the motor's frame of reference, neither sphere is spinning because both of them and the motor are all spinning at the same rate. As a result when you turn the motor on, it creates a uniform torque (theoretically) causing the spheres to rotate in opposite directions. If the motor works at right angles to the primary axis of spin then in a given day an object on the inner sphere would experience a constantly changing gravity cycling in a sine wave motion from 0 to 1 G twice per day.

Question is, how would you get in, or out of the colony?


EDIT:
As an afterthought, to ensure there are no "dead" spots or places that do not get their fair share of G forces you need to ensure that the speeds of the spheres are at least relatively prime. For example if you start both spheres spinning at some RPM that is prime, and then engage the motor to turn at some other prime RPM times 2 ( assuming both spheres have the same mass and the stator and rotor are the same mass...that pesky equal and opposite reaction thing...) then you should be good to go. Less of course the "how do I get in or out?" bit.

I admire your creative solution. This is all quite an elaborate design, one which I have a difficult time comprehending, but would it really take that much complexity?

Maybe it takes that harmonic calculation you mentioned in a previous post. Even in 1 rotating rigid sphere given torque, I would expect at some point a cycle to be established where the man (With 1G becuase he's initially standing at the equator) would return to the coordinates in space he started at. In that case does he return to feel 1G or does the introduction of torque forever take that force away?

 

[wysard]

It's not really all that elaborate, just two spheres one inside the other, like a box inside a box. And the advantages it offers in terms of ease of modelling forces involved and a real world ability to isolate, monitor and control the torque force you specified makes it hard to beat, although I'd love to hear any other ideas.

As to the reason for the concern for the harmonics is that while in your visualization we can make the man start at 1G, and by some torque, float down to near zero and back in a day, try this experiment. Close your eyes and imagine the sphere you want, and then put a torque on it. But imagine you don't know where the man is standing! Suddenly instead of a truly simple solution that fits just where you originally imagined the man, you must now create a solution that always works, no matter where the "mystery man" is standing on the inside of the sphere.

By the same token, if you don't know where the man is standing, imagine he started instead of at the equator, he started somewhere around the 45th parallel. If you make the torque an even divisor of the original rate of spin it is VERY easy to wind up with a scenario where the man NEVER gets to neither Zero, nor to One. Those are the "dead zones".