It might be possible to build it in modular form; each bit having its own directional propulsion system (on the underside, to minimise thrust against adjacent modules) that could be networked to act in unison. Link the modules together with a hydraulic rams that drive pumps when the modules move relative to one another - the modules around the perimeter of the collection would not only damp out most of the swell (leaving the central ones quite stable), but would generate power as they did it.
I’m sure there would be a thousand technical problems to overcome, but I can’t think of anything immediately insurmountable doing it this way. If you were cunning enough with the linkage system (I’m thinking of Rubik’s cube here - where you can move the parts relative to one another without ever detaching them), you could even reconfigure the module arrangement and ‘squirt’ the island through a large canal or strait or something.
On the man-made, self-sustaining iceberg front, The WWII Project Habakuk seems your best bet. It’s built of Pykrete (ice with wood pulp frozen in) I don’t recall the optimum ratio (16% pulp?) but you can easily Google Pykrete. IIRC, Wikipedia had a nice entry.
Pykrete is somewhat self-insulating, and has remarkable resistance to melting, as well as being remarkably tough (Lord Mountbatten demonstrated this by firing a gun at a block of ice and shattering it; the bullet he shot at the equivalent Pykrete lock bounced back to hit US Adm Ernest king in the leg (or penetrate his pants leg, depending on the account).
A “Habakkuk” ship was built, using cardboard tubes for cooling air. When the project was abandoned, the ship didn’t melt until well into the summer.
With a roof of solar cells providing both shade and some fraction of your refrigerating power, your energy needs might not be as atrocious as one might imagine
I wrote a Star Trek short story a few years ago in which an Intrepid-class starship, like Voyager, puts down in an ocean on a Class-M world. She floats without any problem. The chief engineer adjusts the gravity field to prevent seasickness in the crew, and they leave a satellite overhead to keep an eye on local weather and to warn them of any freak waves. Otherwise, no problem. They even open some of the upper airlocks and go swimming off the upper primary hull.
>Earth is not floating in the atmosphere. It is not being held up by the force exerted by the surrounding fluid (atmosphere).
Well, it is floating, and it’s surrounded by atmosphere, but its buoyancy in air is unimportant in keeping the system the way it is. So we are interested not just in floating but in the buoyant kind of floating.
More to the point, perhaps a better reference is the Sargasso Sea, which is a floating agglomeration of seaweed and the like out in the Atlantic Ocean. I’ve heard it sometimes amounts to a big island. It stays there because surface currents flow together and meet at that location, only to descend together, and because it’s composed of lighter materials that don’t descend with the currents. Somebody has proposed farming it.
One of the problems with very large floating structures is that they cannot follow the peaks and troughs of waves. A smaller boat will ride up and down with a wave, but a bigger ship may find itself with the bow at the peak of one wave, and the stern at the peak of another, with nothing supporting the middle. Then the back of the ship breaks, and it sinks. So you either have to build something small enough to ride each wave, or something strong enough to hold its own weight when supported at each end only, or something so massive that the size of the wave troughs is insignifiant, or you have to make your floating thing flexible so that its various parts can ride the waves. The last would kind of suck from a livability standpoint, so we’re left with really really big, average sized, or really really strong.
As for the size of things that float in air, how about a balloon that can fly into orbit? Such a balloon couldn’t stand the jostling of the lower atmosphere, so it would be assembled at a permanently floating ‘airbase’, and fly between that base and orbit, well above the weather.
The balloon (called the ‘ascender’), would be 1.8 kilometers long. That’s pretty big…
Buckminster Fuller didn’t understand the huge forces that would be on such a structure in the lower atmosphere. What would a big wind shear due to a floating geodesic sphere? Or a hurricane?
That’s why the big balloon I linked to above can only fly from orbit to a permanent floating platform that’s well above most of the atmosphere, and high enough that it’s immune to weather.
I’m sure that Fuller understood weather and other natural forces just fine. Clearly there would be serious practical issues involved in actually building a floating bubble city. I’ve always thought of it as an interesting conceptual exercise, not a serious practical suggestion, unlike the Triton concept which was seriously considered for a while.
