Selection Rule

In physics and chemistry a selection rule, or transition rule, formally constrains the possible transitions of a system from one state to another. Selection rules have been derived for electronic, vibrational, and rotational transitions. The selection rules may differ according to the technique used to observe the transition.

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Famous quotes containing the words selection and/or rule:

    Judge Ginsburg’s selection should be a model—chosen on merit and not ideology, despite some naysaying, with little advance publicity. Her treatment could begin to overturn a terrible precedent: that is, that the most terrifying sentence among the accomplished in America has become, “Honey—the White House is on the phone.”
    Anna Quindlen (b. 1952)

    Do I dare set forth here the most important, the most useful rule of all education? it is not to save time, but to squander it.
    Jean-Jacques Rousseau (1712–1778)