Question

when was Albert introduces

Answer 1

In 1905, Albert Einstein had four papers published in the Annalen der Physik, the leading German physics journal. These are the papers that history has come to call the Annus Mirabilis Papers.

In one of the four papers on mass-energy equivalence, Einstein deduced from his equations of special relativity what has been called the twentieth century's most well known equation: E = mc2. Einstein's relativity theory revolutionized scientific thought with new conceptions of time, space, mass, motion, and gravitation.

The equation E=mc² (energy equals mass times the velocity of light squared), became the foundation for the development of atomic energy.