Quantum physics (quantum theory, quantum mechanics)

QM : Heisenberg
• Heisenberg’s “matrix mechanics”
(Werner Heisenberg, 1925)
o Matrix mechanics consists of an array of quantities
which when appropriately manipulated give the
observed frequencies and intensities of spectral lines.
o Physical observables (e.g. momentum, position,..) are
“operators” -- represented by matrices
o The set of eigenvalues of the matrix representing an
observable is the set of all possible values that could
arise as outcomes of experiments conducted on a
system to measure the observable.
o Shown to be equivalent to wave mechanics by
Erwin Schrödinger (1926)
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