I've seen this in physics demonstrations. It's not a microwave or other EMF wave. It's a sound wave being propagated by a high-frequency carrier wave. It's a neat trick and the beam is tight, but it's not some hidden microwave thing that only you can hear.
I've seen this in physics demonstrations. It's not a microwave or other EMF wave. It's a sound wave being propagated by a high-frequency carrier wave. It's a neat trick and the beam is tight, but it's not some hidden microwave thing that only you can hear.