The Joo Janta Peril Sensitive Staircase.

[BJ]

This is an older thought I had when reading about meta-materials with a negative refractive index.

Someone, sooner or later, is going to come up with a coating which will essentially render glass invisible in air (in much the same manner that it is in fact invisible in glycerine, and plexiglass is invisible in water, (that's how a magician walks on water IFYDKB)). And about five minutes later an architect is going to design an invisible staircase or skybridge out of it. Then five seconds after it's installed, one of the builders will be on his back beneath it contemplating visions of lace and elastic and maybe even a little less.

Sooo. Joo Janta. For two reasons. One, the practical, as they are being climbed, have the steps ahead, beneath and behind darken, cloud or light up beneath the climber's feet. And two, the aforementioned Donny boy Trump under the skybridge.