O'Neill cylinder

[8] This would be because of an abundance in food, climate and weather control, and the fact that there would be no need for vehicles that use combustion engines that would create smog and pollution.

[8] The inhabitants would also keep themselves active and entertained by practicing current earth sports such as skiing, sailing, and mountain climbing, thanks to artificially generated gravity due to the cylinder's rotation.

At the radius described by O'Neill, the habitats would have to rotate about twenty-eight times an hour to simulate a standard Earth gravity; an angular velocity of 2.8 degrees per second.

People would, however, be able to detect spinward and antispinward directions by turning their heads, and any dropped items would appear to be deflected by a few centimetres.

[1] These would not be single panes, but would be made up of many small sections, to prevent catastrophic damage, and so the aluminum or steel window frames can take most of the stresses of the air pressure of the habitat.

O'Neill and his students carefully worked out a method of continuously turning the colony 360 degrees per orbit without using rockets (which would shed reaction mass).

Once the plane formed by the two axes of rotation is perpendicular in the roll axis to the orbit, then the pair of cylinders can be yawed to aim at the Sun by exerting a force between the two sunward bearings.

In 1990 and 2007, a smaller design derivative known as Kalpana One was presented, which addresses the wobbling effect of a rotating cylinder by increasing the diameter and shortening the length.

The logistical challenges of radiation shielding are dealt with by constructing the station in low Earth orbit and removing the windows.

[16] At a Blue Origin event in Washington on May 9, 2019 Jeff Bezos proposed building O'Neill colonies rather than colonizing other planets.