Two Forms of Levitation

One involves the familiar use of magnets, which is effective but problematic because of energy requirements and some other stuff. However, once we have room-temperature superconductors, we can build Moebius monorails and have all sorts of fun.

Then there's levitation involving sound waves, which works well but has the obvious drawback of being quite loud. Apparently the way round that is to use 24 kilohertz, above the range of human hearing. Annoying for dogs, though. Anyway, in the absence of sound-levitated monorails that upset Fido, scientists use this amazing technology for manipulating liquid droplets and stuff. Useful if you want to avoid contamination, which is a risk if you're wielding a pipette. Anyway, here's sodium and water drifting together, whereupon wackiness ensues.