Why (and How) does it float?
[S3 Physics - Pressure & Work Done]
I don't have to explain too much here. It speaks for itself.
Cool, huh? It's quite simple, really. The wires outside want to become loose, and they make the top part fall downwards. But, that makes the inner wire tense, which stops it from falling.
The reverse is also true - The wire inside wants to become loose, and pushes the top part upwards and away from the bottom. But doing so causes the wires outside to tense and keep it in structure.
As a result, the wire inside and wires outside are constantly working against each other. One wants the top part to fall downward, and the other wants the top part to fall upward. Hence the weird shape of the tensegrity structure.