>>11225630>Any hopes for metamaterialsNone at all I'm afraid. Pretty much ever, "'amazing material just around the bend,' researchers say," is just grant farming.
While this image is quite a big meme fest, check out the white section listing specs for celestial bodies and the viable colony section. Ridiculous amounts of radiation shielding aside, there are a few planet possibilities for colonies. Those planets provide nearly 1g, allow normal pressure at floating city altitude, and other than Venus they have high fuel atmospheres for colony use along with being much cooler than frying temps. It'd be easier to heat something up than cool something off after all. Rotations for Saturn/Uranus/Neptune are 10.52 hours for 1 Earth day/17.24 hours for 1 Earth day/>16 hours for 1 Earth day, respectively. Thus, all of those could probably have a sky hook if those things were possible, baring ring interference over all 3 of course. Though, I don't see the need.
The floating city idea comes from the the pressure you mention. A balloon here on earth need to have a gas that has less pressure (lighter than air) than the air you breath right? Well, on Venus, Saturn, Uranus, and Neptune the 101kpa pressure we have here at sea level is actually way up high in the atmospheres of those planets. So, a "balloon" with normal Earth air and normal Earth air pressure could float around that height somewhere. Thus, a floating city that use normal materials to hold itself together. Jupiter also has a gas pressure zone like that, but its gravity at that zone is too much if I recall correctly.
The fear of crashing isn't too much or a problem when using cellular construction where an explosion would only rupture a scant few cells at most. The rest of the structure's cells would still hold everything afloat without much problem if any.
