18/05/2026
In his 1905 paper, Einstein did not write E = mc^2 .
He wrote:
"If a body gives off the energy E in the form of radiation, its mass decreases by E / c^2
He started with energy (radiation/light) and derived mass as the consequence.
The equation was always m = E / c^2 in his own perception.
The inversion to E = mc^2 came later.From textbooks, from popularizers, from a material philosophy that needed matter to remain central.