What the interfacial layer is (ordered ice → disordered layer → liquid)

17:17The layer in between my ice and my skate is going to be the pseudo liquid layer where there's going to be a lot of molecular disorder, right? Because if you go down the order is really high and if you go up it's fully liquid. There's going to be some transition where the water molecules are behaving in a very unique way. Right? >> That's what this paper was trying to solve. What is the chemistry and the physical properties of that interfacial layer of water molecules >> where there is a high disorder? >> Yes, where there's high disorder. And can that actually tell us something about why the viscosity is so high? Right. And what they used is something

17:57called an atomic force microscope but with a tuning fork. So an atomic force microscope is this incredible technology. This is one of the technologies that I thought should win the Nobel Prize this year that that I called. Didn't get it but I think it's coming. The AFM is an amazing tool. It's effectively a cantal lever. So you've got a little pointy thingy that's pointed downwards, right? And if I've got a sample with molecular level irregularities, like I'm talking tens of nanometers to less when I bring this thing up, it's going to move up and down, right? Because the literal atoms on my surface are going to resist the cantal lever. And if I have a laser that's shining on the cantal lever and then it's on a detector, as the as the

18:39cantal lever moves, the laser on that detector is going to move, right? And then I'm going to be able to sense these tiny surface level atomic irregularities. And that's what the atomic force microscope is doing. It's it's been revolutionizing surface chemistry studies like all over the place from biology to chemistry, everything. Right. I think if I remember correctly, the way we analogized it was it's like >> the when you have a record player. >> Yes, exactly. >> And it's reading a record but just with a laser for precision on the readings. But just >> and the records are atomic scale. >> Atomic scale versus whatever records are currently. But just as a visual analogy

19:22for folks that that's kind of the reference point. >> Yeah, that's exactly right. And with the atomic force microscope, the problem is you're only going to read the sort of XY or sorry, the Z displacement, right? The up and down displacement. What we want to know with ice cuz we're sliding >> is we got to we got to get this, >> right? So what they what they they made a tuning fork autonomic force microscope. A tuning fork is is if if you're a musician, you know these like two prongs of metal that will vibrate at a specific frequency. So, if you want an A, the the size of these prongs tells you that it's only going to vibrate at an A. And so, when you bounce it, it's going to be like, and it's only going to be at this really clean tone. They took

20:04a tuning fork microscope and they attached it, sorry, they made they took a tuning fork and they attached it to an atomic force microscope. They attached that to a bead that would interface with the ice. So, the bead is kind of like my skates. >> Yes. >> I have a tuning fork on top. >> Yes. >> Okay. That tuning fork is going to vibrate sideways. >> Yes. >> And that sideways vibration is really tapped in to whatever resonant frequency that tuning fork is at. Right. If I've tuned that tuning fork to an A, it's only really going to vibrate at an A. >> Right. >> Right. And the up and down can be the atomic force part. I see. >> But the sideways part can be my tuning fork vibrating at a very specific frequency.

20:44>> Yes. >> Okay. So now I can get both the up and down motion >> and the side to side motion