Quantum Mechanics as a Universal Theory, Classical Appearances in a Quantum World
Bernard d’Espagnat
This chapter reviews and discusses the essential aspects of three theories—or rather clusters of theories—that, however distinct, all lay special emphasis on more or less the same points. The theories discussed are the Everett relative state theory, the theory of environment-induced classical appearances and the Gell-Mann and Hartle cosmological theory. These points essentially are that if quantum theory is to be applicable to the world as a whole, this implies that it should be expressible with no reference to classical instruments lying outside the analyzed system and it should somehow account for emergence of classical appearances within this world. The fact that quantum mechanics works so remarkably well as a tool for making reliable predictions in all sorts of domains is of course felt by many physicists as a powerful incitement to the quest of a quantum theory of the universe as a whole.
CRC Press eBooks•May 4, 2018•0 citations