Beauty & Simplicity

The first time I saw the famous E=mc² formula I'm sure it was not in a physics class: no other physics formula whatsoever became so popular and was so spread around (from t-shirts to comics) as this one. The main reason is its beauty and simplicity. Einstein's theories grew up on a fertile ground, prepared by several experiments performed in the previous years (I mention here for instance the famous 1887 Michelson-Morley experiment which provided a measurement of the speed of light). Einstein himself spent many years of study before arriving to present his special theory of relativity. Nevertheless, the final picture was apparently "clear" and confirmed what Einstein was saying: "most of the fundamental ideas of science are essentially
simple and may, as a rule, be expressed in a language comprehensible to everyone".

The experimental confirmation of E=mc² didn't arrive soon. In 1933 Irene and Frederic Joliot-Curie obtained the first photograph showing the conversion of energy (a quantum of light) into mass (two particles curving away from each other). Einstein said that "the whole of science is nothing more than a refinement of everyday life": since those days
his beautiful theory was brought into reality and became part of our life.