This is just bizarre, I had no idea this effect even existed.
@Tony L recognise this? This is the guy who worked out the maths, Lev Landau - no not @droodzilla This picture is from his prison cell in Lubyanka - he was released because he would be useful to Stalin in inventing a Russian nuclear bomb. He also set out the modern way of describing quantum mechanics.
Haha, nice one! Total genius, of course - one of the most important physicists of the 20th century.
One of the more bizarre Landau-related developments in recent years is this:
https://www.theguardian.com/film/20...had-absolute-freedom-until-the-kgb-grabbed-me
His life and times are now the inspiration for a gargatuan, Truman Show style experiment, sections of which will be released as movies. It sounds completely bonkers (and therefore a must-see, in my view).
My interest in him relates to his work on phase transitions (e.g. water to steam, but also more esoteric stuff like the onset of superconductivity as a material is cooled) He developed a very general framework for thinking about such phenomena, which were not well understood until well into the 20th century. One of the "Wow!" moments in my undergraduate degree was a lecture about Landau's theory of phrase tranisitions which, despite its power and generality, can be explained using GCSE level mathematics (a bit like special relativity relying on nothing more complicated than Pythagoras).
One of my regular bugbears is not quite "getting" the concept of chemical potential. I mean, I can give you a definition, but I don't have much of an intuitive feel for what it represents. I sometimes wonder if a chemist might understand it better, having been introduced to the idea earlier. Same goes for "osmotic pressure".I taught thermodynamics for nearly 20 years, but only to chemists
One of my regular bugbears is not quite "getting" the concept of chemical potential. I mean, I can give you a definition, but I don't have much of an intuitive feel for what it represents. I sometimes wonder if a chemist might understand it better, having been introduced to the idea earlier. Same goes for "osmotic pressure".
Thanks, that's as clear an explanation as I've ever read. And not a partial derivative in sight!Yeah, it's a daft expression, it was taken from the idea of electrical potential and the flow of electrons. The Gibbs energy (which chemists usually care about i.e. open systems) changes if the pressure or temperature changes (ignore that), but also when the amount of each substance changes. The amount of each substance changes, trivially, by how much is put in, but during the course of a reaction or physical process. The chemical potentials are just the contributions of each species to the total Gibbs energy.
Osmotic pressure is cool. It's really the same idea - a solution of something in a solvent isn't at equilibrium with respect to a pure solvent, the Gibbs energies of the systems are different. To achieve equilbrium you must apply a pressure to the solution i.e change the chemical potential of the 'solvent' to match that of the pure liquid, so that's the exact opposite of the osmotic pressure
He also set out the modern way of describing quantum mechanics.