Step 1: Create a shape changing structure with the following properties:
- Object must be strong (carbon nano-tubes?)
- Object would resemble a tinker toy sphere (when in sphere form)
- Object could collapse into a ripply circle (the flattened sphere)
- Object would snap from flat to sphere as a result of electromagnetic influence or mechanical external adjustment
- Object would be air tight so that if it snapped from flat to sphere, it would be at vacuum inside
- Objects volume + the payload would have to weigh less than air for it to fly (or really..to float at the air buoyancy point where equilibrium was found) (its materials would weigh more than air but when accounting for the empty volume it would average to less. One cubic foot of air weighs 0.0807 lbs or 1.2912 ounces at standard temperature, pressure, and chemical composition on Earth).
Assume we'll eventually be able to make such material. Now Imagine air and water applications. Imagine the childhood dream of flying (floating) around town with a bunch of helium balloons tied to your wrist. Now imagine you wanted to do the same thing with this geometric construct. Assume you weigh 200 lbs. To achieve lift, your sphere(s) must take up as much volume as 200 lbs of air does plus a little extra to account for their own weight. 2,478 ft^3 of air weighs about 200 lbs. For a visual, if that was one sphere, it would have a diameter of at least 16.78 feet (a little more to account for its own weight). In order to control up and down, many sphere's would be required. Intuition says the most efficient method of sizing the spheres would be to think of this as 0's and 1's (binary). In other words, the volume of the smallest sphere would be half that of the next smallest sphere, and so on. This way you could have excellent resolution for controlling up and down. If, however, expanding and collapsing the spheres took a lot of energy, you may not want to go with this method.
Of course it may be possible to have fine resolution on each sphere. Imagine a gear on the bottom end of the sphere. Turning this gear clockwise would slowly snap the full sphere part of the way toward its collapsed self. This way the volume of the vacuum structure would be adjustable in order to displace a certain amount of air. Imagine using one of these objects to aid in rocket launches to conserve fuel? It could also aid on reentry. Imagine the collapsed objects going along for the ride and only used as a backup on planes and boats.
How much could a 100 foot diameter vacuum sphere lift? 42254 lbs (though part of this of course would be its own weight)
What about a 1000 foot diameter vacuum sphere? 2,094,393 TONS! (2000 ft = 1 ton)
Probably ridiculous, but fun to think about nonetheless. The future will undoubtedly be much more radical.