Interpretations of Quantum Mechanics - Historical Background

Historical Background

The definition of terms used by researchers in quantum theory (such as wavefunctions and matrix mechanics) progressed through many stages. For instance, Schrödinger originally viewed the wavefunction associated with the electron as corresponding to the charge density of an object smeared out over an extended, possibly infinite, volume of space. Max Born interpreted it as simply corresponding to a probability distribution.
There are two different interpretations of the wavefunction:

1. In one it corresponds to a material field;
2. in the other it corresponds to a probability distribution — specifically, the probability that the quantum of charge is located at any particular point within spatial dimensions.

The Copenhagen interpretation was traditionally the most popular among physicists, next to a purely instrumentalist position that denies any need for explanation (a view expressed in David Mermin's famous quote "shut up and calculate", often misattributed to Richard Feynman.) However, the many-worlds interpretation has been gaining acceptance; a controversial poll mentioned in "The Physics of Immortality" (published in 1994), of 72 "leading cosmologists and other quantum field theorists" found that 58% supported the many-worlds interpretation, including Stephen Hawking and Nobel laureates Murray Gell-Mann and Richard Feynman. Moreover, the instrumentalist position has been challenged by proposals for falsifiable experiments that might one day distinguish interpretations, e.g. by measuring an AI consciousness or via quantum computing.