# Einstein

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## Einstein

**Albert.**1879--1955, US physicist and mathematician, born in Germany. He formulated the special theory of relativity (1905) and the general theory of relativity (1916), and made major contributions to the quantum theory, for which he was awarded the Nobel prize for physics in 1921. He was noted also for his work for world peace

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

The following article is from

*The Great Soviet Encyclopedia*(1979). It might be outdated or ideologically biased.## Einstein

a unit of energy of electromagnetic radiation in the optical range. The einstein, which is used in photochemistry, is equal to *N _{A}hv*, where

*N*is Avogadro’s number and

_{A}*hv*is the energy of the photon. It was named in honor of Albert Einstein and is abbreviated E. When a radiant energy of 1 E is absorbed, the photochemical conversion of 1 mole of the substance should occur, according to Einstein’s law of photochemical equivalence. It follows from the definition of the einstein that the dimension of the unit is determined by the radiation frequency (

*v*) (

*h*is Planck’s constant).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

## einstein

[′īn‚stīn] (physics)

A unit of light energy used in photochemistry, equal to Avogadro's number times the energy of one photon of light of the frequency in question.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.