An abbreviation for trinitrotoluene, it is a pale yellow material used as a high explosive first prepared by German chemist Julius Wilbrand (1839–1906). The TNT equivalent is a convenient way of expressing the magnitude of an explosion by calculating the amount of TNT which, when detonated at a particular point, would cause the same level of blast wave damage. The ton of TNT is a unit of energy equal to 4.184 gigajoules of energy, and is the approximate amount of energy released on the detonation of one ton of TNT.