Abstract
Is it possible to understand any physical properties once its Hamiltonian or its Lagrangian is known? This understanding process seems not to be useless to find unknown physical phenomena. Therefore, the operational approach is very powerful to overcome this conflict. We tried to reformulate some physical theories from an operational viewpoint following in Brillouin's footsteps,. However, as information theory is not currently applicable to situations where there are only a small number of samples, we could only consider macroscopic physical theories: equilibrium thermodynamics and equilibrium statistical mechanics. The optimal information-theoretical process corresponds to the equilibrium macroscopic system, and its essence is a sufficiently large number of samples.
Yutaka Shikano