A theorem named for him relates the time derivative of an (*) operator's expectation value to the expectation value of the operator's time derivative and the operator's commutator with the Hamiltonian.
This person developed the wind-tree model of billiards, which is composed of an arbitrary array of rectangular scatterers. He names a basic Markov model for the exchange of gas particles between chambers in which a single particle swaps chambers at each timestep. He invented the name now used for objects that only transform properly under a 720-degree rotation; those objects are spinors. A theorem named for him relates the time derivative of an (*) operator's expectation value to the expectation value of the operator's time derivative and the operator's commutator with the Hamiltonian. The Langevin-Landau-Lifshitz metric was shown to be the best approximative solution to a question he posed about the Born rigidity of a certain object. For 10 points, name this Dutch-Austrian physicist who formulated a paradox about a relativistically rotating disk.
This person developed the wind-tree model of billiards, which is composed of an arbitrary array of rectangular scatterers.
Paul Ehrenfest