Experimental petrology 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 from experiment to experiment, in general the procedure involves evaluating a synthetic rock or magma (created from a blend
What Is History? that historians deem unimportant, and "historical facts", information that the historians have decided is important. Carr contended that historians arbitrarily determine which of the "facts of the past" to turn into "historical facts" according to their own biases and agendas. For this reason, Carr argued that Leopold von Ranke's famous dictum "wie es eigentlich gewesen" (show what actually happened) was wrong because it presumed that the "facts" influenced what the historian wrote, rather than the historian choosing what "facts of the past" he or she intended to turn into "historical facts". At the same time, Carr argued that the study