&gt; <i>The criticism of centripetal force as a substitute for planetary gravity is that it has directional vectors of force that would make you dizzy every time you turn your head. Presumably, the larger the structure, the more subtle these forces become. Perhaps humans can get used to these lateral forces over time, if indeed it is an issue at all.</i><p>I wonder if astronauts would develop &quot;land sickness&quot; that affects some people coming from cruises - constant dizziness when out of spin gravity.