Scott Waitukaitis

And if you just manipulate sound fields in a very clever way, you can lift stuff up with sound.

How did I not know this?

I mean, it's actually, you know, in the research world, it's, you know, tons of people doing it.

Yeah, so the sound is obnoxiously loud.

But good for us, it's an ultrasound, so we can't hear it.

Now, we don't bring any dogs to the lab because I think they would really not appreciate it.

Right, okay.

Yeah, bingo.

So we levitate a quartz sphere above a quartz plate, and then we turn off the levitation so the sphere falls and bounces off the plate.

We catch it again with the sound.

And in principle, they should not exchange charge because they're the same exact damn thing.

But they do exchange charge always.

And in fact, every sample behaves like a completely different material, even though they're the same exact material.

Well, you know, that's the question that we wanted to answer because clearly there must be something different about the samples for them to have charge move in one direction or the other.

Yeah, I mean, of course, there must be something different about them.

Otherwise, they would not transfer charge at all.

And the thing that we found is it's nothing to do with differences, say, in the bulk inside of the material, but actually it's differences on the molecules from the air that adsorb to their surfaces.

And adsorb is just a fancy way of saying stick.

So any object in any environment will develop kind of a layer of molecules on its surface that it kind of attracts from its environment.

And really, this is like a monolayer of molecules.