In this paper, extending his theory of the special theory of relativity, Einstein first propounded his famous ratio for the equivalence of energy and mass according to which the energy of a body is equivalent to its mass times the square of the velocity of light. The idea of matter as essentially irreducible was abolished and the way towards nuclear fusion was theoretically opened. [The atom was first split by Lise Meitner in 1939.] For further information see our record in the People table under the author's name and the entry under Relativity in the Topics table.
Editors. "Ist die Trägheit eines Körpers von seimen Eneergienhalt abhängig?". The Literary Encyclopedia. First published 28 October 2000
[https://www.litencyc.com/php/sworks.php?rec=true&UID=4423, accessed 21 February 2019.]