David Copperfield

I thought I knew it, but here's explanation,
The performer is supported by a pair of arrays of several fine wires that remain invisible to the viewing audience. The wires are less than 1mm thick, but can support 100kg each. The wire arrays are mounted at the hips, near the human center of mass, to a harness worn under the clothing. This creates a balance point facilitating a wide range of movements while suspended. The wires are attached to a complex computer-controlled rig above the stage that maintains the tension in each, and keeps each array of wires perpendicular to the viewing audience. During the later phases of the performance, two hoops are used simultaneously, which aids the deception as the hoops do not come into contact with the gear. In the glass box demonstration, the top of the box is threaded between the two sets of wires in a vertical position, before being rotated ninety degrees and lowered into place. The wires remain in place while the performer is in the glass box, passing through crevices between the lid and the sides. Since the box limits movement, and he is only able to rotate on one axis, he stays side-on to the front of the audience throughout this part of the performance. When he flies with the girl, he holds her in front of him, and she does not come into contact with the set-up.