Feynman's Lectures on Entropy

Part 1

Part 2

Mr Feynman is famous for saying that no one understands quantum mechanics. This coming from someone who developed much about quantum mechanics that we all learn in school.

This lecture is about Entropy. Entropy is a very difficult subject for physicists. Entropy is an obvious subject for restaurant owners, composers, mothers, automobile mechanics, and just about everyone else who actually accomplishes difficult projects in this world. Obvious in the sense that order and achievement come from hard work and vision, while there is a very strong force in all life that tears apart and disorganizes. The gardener knows that plants seeks to grow, while she has the vision and intelligence to organize a beautiful garden where each plant can play its perfect note. The gardener finds a way to take all that available energy of the plants and put it to a purpose that is beyond what would happen if all where left to chance. The physicist is extremely hard pressed to account for all this, and has chosen instead to look at the opposite, characterizing the laws of disorganization and the laws of how energy becomes no longer available.

Energy becoming no longer available for useful work is one definition of Entropy. Many physicists ignore the fact that this definition of Entropy, by including the word "useful", has already introduced the ideas of vision and purpose. Press them on this point and they hastily retreat. But at the end of the day, we all know what is at stake. They will bare their teeth and say, "the second law of thermodynamics has never been disproven". Each living cell, with its stupendously organized activity, is a contradiction to the 2nd law. An animal body with a trillion cells organized yet again into a larger unit of fantastically lower entropy is yet another contradiction to the 2nd law of thermodynamics. Ask the physicist about this and the answer will be that "in some other part of the Universe the Entropy must have increased". If that is so, then where? what data supports that? What experiment has been done to investigate that claim? You will find none.

This lecture of Mr Feynman is my favorite so far of any I have watched. I was especially struck by two parts. The first is his statement that the Universe must have been more organized in the past. This is a simple application of the principle idea of the lecture. If all things become homogenized in time, if all temperatures equalize, if all distinctions become blurred, then in the past the Universe must have been more organized than it is now. Think of what that must mean. More organized than stars with planets going about, and moons going around the planets, and each planet with its own weather systems. More organized than all the complexity of organic life on Earth. More organized than billions of galaxies laid out on filaments across all time and space. More organized than filaments filling each galaxy connecting each star to another and containing complex "organic" molecules like sugars and amino acids. The early Universe must have been more organized than this?

The second part I love is the ending where he lays out what we would today call "emergent properties". Emergent properties is, I think, a very harmful term. Harmful to right thinking and feeling. Emergent properties says something like, all the exact laws of how electrons and protons interact lead (somehow) to all the laws of chemistry, which lead (somehow) to all the laws of cellular biochemistry, which lead (somehow) to all the laws of cells, which lead (somehow) to all the laws of how organs interact, which leads (somehow) to all the laws of the human body, which lead (somehow) to all the laws of though, feeling, and perception. This is hogwash on a grand scale, and to put such chicanery forth in the name of science is, as I have said, harmful. But.... Professor Feynman does not do it just like that. With all his brilliance there is somehow the intellectual humbleness in his description, and I gratefully hear a very different message than "Emergent Properties". I leave you to watch and see what I mean.