Outline Summary
... The main conceptual changes in understanding the physical world that were discovered in the twentieth
century are presented. Starting with the introduction of the quantum of light by Planck in 1900 and
ending with the standard models for cosmology and particle structure as we understand them now.
A ...
Quantum logic
In quantum mechanics, quantum logic is a set of rules for reasoning about propositions that takes the principles of quantum theory into account. This research area and its name originated in a 1936 paper by Garrett Birkhoff and John von Neumann, who were attempting to reconcile the apparent inconsistency of classical logic with the facts concerning the measurement of complementary variables in quantum mechanics, such as position and momentum.Quantum logic can be formulated either as a modified version of propositional logic or as a noncommutative and non-associative many-valued (MV) logic.Quantum logic has some properties that clearly distinguish it from classical logic, most notably, the failure of the distributive law of propositional logic: p and (q or r) = (p and q) or (p and r),where the symbols p, q and r are propositional variables. To illustrate why the distributive law fails, consider a particle moving on a line and let p = ""the particle has momentum in the interval [0, +1/6]"
