 Before we look at hydrogen bonds and free energy, there's something else I just need to share with you because it's important. An important side goal of this class is to get you to think. I think there are too many things we learn by heart and too little we think, and most problems in the world can actually be solved by thinking a little bit. So you are young, and even this was even before I was born, but in 1962 there was an amazing discovery by Fidjakin and Deryagin. They claimed to have discovered something called polywater. That is, under some very special condition, in particular we push waters to very small capillaries, so where the surface tension and everything has special physical states, they argued that under some conditions they cut it up with a strange extra phase of water that was polymerized, and thus the name polywater. They argued that this system had very special properties. It had a freezing point between 243 to 213 Kelvin, so significantly lower than the 273 Kelvin of normal water, and it had a boiling point that was much higher, so 523 to 573, it's as in my notes. So it has a much wider span than normal water where this would be liquid, but it would have quite different states and properties. This led to a, I wouldn't say outward, but this led to a frenzy in the scientific world. Remember this was during the Cold War and everything. Some research in the West couldn't really reproduce this, and there was talk in the US about the fear of Russia developing a polywater gap, because they were far ahead of, people feared that Russia was far ahead of them in terms of the science here. People even tried to reproduce this, and there were some attempts where they could they claimed to reproduce it, and then there was a surprising amount of time that actually passed before it was eventually Feynman that debunked this completely. There are a few papers in Canvas that are worth reading, not because this is important in terms of the polywater sense, but I, there are many things happening around COVID and everything, and I do think that we should think more about being skeptic and everything. And in terms of being skeptic, I would argue that aren't with what you know, you should have been able to debunk this a long time ago. It should just have taken anybody who's smart, such as Feynman, a few minutes. And you can do that with our f equals e minus ts or free energy curves. So let's draw it. Here is a plot where I, on the x-axis I have temperature, and on the y-axis I will plot free energy. Let's be chemists today, so let's use Gibbs free energy. And then we have a few different curves here, because I have different faces, right? So let's see here. So I get this right. At very low temperature, I'm going to have ice, and you will just have to trust me that the shape of the curves will look something like this. At intermediate temperatures, I'm going to have a some sort of liquid face, and at even higher temperatures, I'm going to have some sort of gas face. So this would be gas, this would be normal liquid water, and this would be ice. You can also draw something else here, right? We know that this is 273 Kelvin, because what happens is 273 Kelvin. Here it's better to be ice, because it has the lowest free energy, and suddenly at 273 Kelvin, it's better to be liquid. So from a phase transition, because this free energy is lower, and here at 373 Kelvin, the gas face will be better. So we will always stick at the lowest free energy. If we believe every single word they were saying about poly water, it should have a freezing point that was say 230 or 40. So we'd have a freezing point here, and then it would have a boiling point up here somewhere, whatever that is. So you should have the poly water should be here. What does this mean? Remember the fundamental stuff about the laws of thermodynamics. What this is saying, that poly water always has a lower free energy than liquid water. Anytime you start having a reaction, any water molecule that has a chance to choose would prefer to be poly water. Now some reactions won't happen instantly, but the world is 4.3 billion years old. If this were true, we would hardly be able to find a single water molecule in the normal liquid phase. Every single water molecule should have turned to poly water. Now this does not describe what went wrong in the experiment, but the whole point we don't have to explain what went wrong in the experiment. All you need to be able to do is show this, oh my god, this is completely ridiculous. There is no way these results can be true. And yet this went all the way up to fairly high government officials' worries about poly water yet because people didn't think until Feynman, of course, the amazing theoretical physicist, pretty much did this reasoning and sorry, it's crap. There is no way that this can be true. So what was it? Well, eventually Dennis Rousseau showed that they had contaminants, sweat, and in some cases they might, if you push a lot of water through these very thin capillars, in some cases it might even have been parts of the glass walls that teared off and ended up in the poly water. And if you just have some few nanoleters or something, that will, of course, change the properties. And if you're then measuring the properties, you're going to end up with something that is not pure water. And that's why they got completely ridiculous results. So a few years later, nobody remembered these results anymore. But history has a tendency, if not to repeat itself, it rhymes. So think hard about things and make sure that unless, until we have proven things, we should be skeptical. Grant claims require grand evidence and support.