Psychohistorical thermodynamics

“I studied physics as an undergrad, and basically what [Asimov] is doing is taking classical thermodynamics and applying it to human behavior. In thermodynamics, you can’t predict what one atom is going to do, but if you have several billion atoms in a contained box, you can predict—very precisely—if you raise the temperature, exactly what the effect on pressure is going to be, things like that. He’s basically saying if you have enough human beings—you have 100 million worlds, all inhabited by human beings—that psychohistory can predict the mass behavior of human beings, without being able to predict any individual human being’s behavior. That’s a cool idea.”