Why it will feel like being on a boat (was Bend it like O'Neill)

--- In spacesettlers@yahoogroups.com, Joe Strout wrote:
> On 5/16/12 9:44 PM, hitssquad wrote:
> > people in the habitat will feel like they are on board a boat, because they will perceive the floor to be tilting this way and then that way at the frequency of rotation.
> What? Why would this happen?

...Because half the time the floor will be moving at less than orbital velocity, and half the time the floor will be moving at greater than orbital velocity. If the habitat is in GEO, and its floor velocity is 400 mph, at noon and midnight (when the habitat cylinder is pointed head-on -- or at least nearly-so when not at equinox -- at the earth) the floor will alternate between a peak velocity of:
GEO orbital velocity (6,867 mph) + 400 mph,

and a trough velocity of:
GEO orbital velocity - 400 mph

-- at the frequency of rotation.

Being thusly overspeeded or underspeeded while being suspended at a particular orbit will cause one to feel a tug in one direction while overspeeded, and then in the other direction while underspeeded. If the habitat is rotating at, say, 2 rpm, then there will be one-minute intervals between the two extremes of tugging force.