Page "Quantum mechanics" Paragraph 3

The earliest versions of quantum mechanics were formulated in the first decade of the 20th century.

At around the same time, the atomic theory and the corpuscular theory of light ( as updated by Einstein ) first came to be widely accepted as scientific fact ; these latter theories can be viewed as quantum theories of matter and electromagnetic radiation, respectively.

Early quantum theory was significantly reformulated in the mid-1920s by Werner Heisenberg, Erwin Schrodinger, Max Born, Wolfgang Pauli and their collaborators, and the Copenhagen interpretation of Niels Bohr became widely accepted.

By 1930, quantum mechanics had been further unified and formalized by the work of Paul Dirac and John von Neumann, with a greater emphasis placed on measurement in quantum mechanics, the statistical nature of our knowledge of reality, and philosophical speculation about the role of the observer.

Quantum mechanics has since branched out into almost every aspect of 20th century physics and other disciplines, such as quantum chemistry, quantum electronics, quantum optics, and quantum information science.

Much 19th century physics has been re-evaluated as the " classical limit " of quantum mechanics, and its more advanced developments in terms of quantum field theory, string theory, and speculative quantum gravity theories.