“If a body gives off the energy L in the form of radiation, its mass diminishes by L/c2. The fact that the energy withdrawn from the body becomes energy of radiation evidently makes no difference, so that we are led to the more general conclusion that the mass of a body is a measure of its energy-content; if the energy changes by L, the mass changes in the same sense by L/9 × 1020, the energy being measured in ergs, and the mass in grammes. It is not impossible that with bodies whose energy content is variable to a high degree (e.g. with radium salts) the theory may be successfully put to the test.”
Albert Einstein (September 27 1905)
On this day (Sept. 27 1905), the physics journal Annalen der Physik publishes Albert Einstein’s paper “Does the Inertia of a Body Depend Upon Its Energy Content?”, introducing the ‘infamous’ equation E=mc².
UPDATE (Sept. 30 2018) — This week has not been an easy one and we could use a good joke. Follow us on Twitter: @INTEL_TODAY Continue reading








