Simulation Using LRO Data Shows More Locations With Ice on the Moon

What I'd be interested on knowing:
How fast would we have to spin something to approximate 1G, and how big would it have to be? (Several times the height of a human is my guess, in order to prevent having stratified gravity.)

Is 1G even optimum or necessary to retain bone mass and a strong heart?

Smaller diameters of "space station" require a higher angular velocity, but in principle there is no specific size restriction if you simply want to achieve a 1g accelleration at floor level. However, using a small diameter has a couple of problems:
1. The accelleration gradient is more extreme (equivalent to gravitational tidal forces). e.g. for a capsule twice the height of a human, your feet would be at 1g, but your head (being in the centre) would be in 0g. Use a bigger diameter and a slower angular velocity and you will reduce the gradient.
2. The coriolis effects associated with high angular velocities make it extremely unpleasant to move around in a fast spinning (hence small diameter) capsule. According to Wikipedia [wikipedia.org] you need to spin at under 7 RPM, preferably around 2 RPM, to make this manageable. At 2 RPM you need a diameter of about half a kilometer to achieve 1g. 7 RPM is a bit more managable, requiring a diameter of 40 metres. Rather than building a cylindrical capsule, a better option might be to have a pair of capsules tethered together with a 500 metre tether.

Source: http://rss.slashdot.org/~r/Slashdot/slashdotScience/~3/8djT9l_p9V0/simulation-using-lro-data-shows-more-locations-with-ice-on-the-moon

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