Demonstrated By: NASA, Argonne National Lab
What Happens:
Objects are suspended in air using ultrasonic standing waves. These standing waves create nodes where the acoustic pressure cancels gravity, allowing the object to hover — in some cases even rotate or move in 3D.

Relevance:
Acoustic waves and EM waves share wave-based physical principles. Acoustic levitation shows how standing-wave fields can suspend solid matter in mid-air — reinforcing the concept of “locking” an object via a structured field.