Experimental petrology it is possible to examine the behavior of a magma body as it slowly cools and crystallizes over time Experimental petrology Experimental petrology is the field of research concerned with experimentally determining the physical and chemical behaviour of rocks and their constituents. Because there is no way to directly observe or measure deep earth processes, geochemists rely on experimental petrology to establish quantitative values and relationships in order to construct models of the deep earth. Experimental petrology can range from creating artificial magmas to measure crystallization behavior to observing recrystallization of minerals at varying P/T (Pressure/Temperature) conditions. Although methodology varies
A Study of History 23 civilizations identified by Toynbee in vol. Vii. This table does not include what Toynbee terms primitive societies, arrested civilizations, or abortive civilizations. Civilizations are shown in boldface. Toynbee's "Universal Churches" are written in "italic" and are chronologically located between second- and third- generation civilizations, as is described in volume VII. The social scientist Ashley Montagu assembled 29 other historians' articles to form a symposium on Toynbee's "A Study of History", published as The book includes three of Toynbee's own essays: "What I am Trying to Do" (originally published in "International Affairs" vol. 31, 1955); "What the Book is For: