7. Basic Quantum Mechanics, QMA.


Summary

Since quantum mechanics is so successful (principle [P3] in Schrödinger’s Cat), we will describe a scheme, called QMA, in which all there is is ‘basic’ quantum mechanics.

[P4] Basic quantum mechanics, QMA is defined as follows:
(1) No particles. There are to be no particles or hidden variables.
(2) No Collapse. There is to be no collapse of the wave function, so that all versions of reality continue forever.
(3) No ‘sentient beings.’ There are to be no ‘sentient beings,’ outside the laws of quantum mechanics, which ‘look into’ physical reality and perceive just one version of reality.
(4) No probability law. There is to be no a priori assumption that the probability law holds.
(5) Linearity. And finally, the theory is to be linear. (This is a technical point which basically implies that each version of reality is isolated from the others.)

We will find in succeeding sections that this bare-bones theory, with no particles or collapse, does very well in describing our perceptions. The only place where it falls short—and it is a fatal short-coming—is in being consistent with the Probability Law.