(quantum mechanics, quantum electrodynamics) A small difference between the energy levels 2S_½ and 2P_½ of the hydrogen atom, not predicted by the Dirac equation, whose detection in the Lamb–Retherford experiment of 1947 foreshadowed the development of quantum electrodynamics (in which the discrepancy is explained to be an effect of the emission and re-absorption of virtual photons); such a difference between otherwise expectedly equal energy levels of hydrogen or any other type of atom.

(photography, chiefly attributive) The use of camera movements to simulate a miniature scene in the resulting photograph.

A shift (change of workers).

simple past tense and past participle of make shift

present participle of make shift

Third-person singular simple present indicative form of make shift

Purkinje effect

(dated) To contrive; to invent a way of surmounting a difficulty.

(intransitive) To vacillate. / (dated, intransitive) To turn round entirely to the opposite point.

An agricultural system in which plots of land are cultivated temporarily, then abandoned (usually when the soil shows signs of exhaustion, or when overrun by weeds) and allowed to revert to their natural vegetation.