Year: 2018 Pages: 6
This article reviews some unappreciated history about E=1mc^2, even before Einstein. In particular, we note Laplace\'s belief that likely when our Sun radiates off a particle of mass, \'m\', at the speed of light, that the Sun\'s mass decreases by that mass, \'m\'. And in an 1899 publication, Hertz refers to a long-standing belief that the total energy of a conservative system is TWICE its kinetic energy, presumably mc^2, instead of (1/2)mc^2. After further analysis, we conclude that Einstein\'s E = 1mc^2 conclusion for radiation was very praise-worthy because it concisely stated and advocated two less-popular proposals of the time. But actually not new proposals! And we offer other thoughts, hopefully helpful.