The Quantum-like Face of Classical Mechanics

It is first shown that when the Schr"{o}dinger equation for a wave function is written in the polar form, complete information about the system’s {\em quantum-ness} is separated out in a single term $Q$, the so called quantum potential'. An operator method for classical mechanics described by a classical Schr"{o}dinger equation’ is then presented, and its similarities and differences with quantum mechanics are pointed out. It is shown how this operator method goes beyond standard classical mechanics in predicting coherent superpositions of classical states but no interference patterns, challenging deeply held notions of classical-ness, quantum-ness and macro realism. It is also shown that measurement of a quantum system with a classical measuring apparatus described by the operator method does not have the measurement problem that is unavoidable when the measuring apparatus is quantum mechanical. The type of decoherence that occurs in such a measurement is contrasted with the conventional decoherence mechanism. The method also provides a more convenient basis to delve deeper into the area of quantum-classical correspondence and information processing than exists at present.