Gray (unit) Gray (unit) The gray (symbol: Gy) is a derived unit of ionizing radiation dose in the International System of Units (SI). It is defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose which measures the energy deposited in a unit mass at a certain position, and of the radiation quantity kerma, which is the amount of energy that is transferred from photons to electrons per unit mass at a certain position. The corresponding cgs unit to the gray is the rad (equivalent to
Socialism: Utopian and Scientific Socialism: Utopian and Scientific Socialism: Utopian and Scientific is a short book first published in 1880 by German-born socialist Friedrich Engels. The work was primarily extracted from a longer polemic work published in 1876, "Anti-Dühring." It first appeared in the French language. The title "Socialism: Utopian and Scientific" was adopted for the first English edition in — the tenth language in which the book appeared. Intended as a popularization of Marxist ideas for a working class readership, the book was one of the fundamental publications of the international socialist movement during the late 19th and early 20th centuries, selling tens