. ge n - ph ] 2 2 M ay 2 00 7 Why E = mc 2 Emerges in the Process of Neutron Capture Ezzat G . Bakhoum

This paper is a short commentary on the 2005 paper in Nature by S. Rainville et al., which claimed to be “the most precise direct test of the famous equation”, E = mc. This communication is directed only to the readers who are familiar with the earlier papers by the author on the subject of mass-energy equivalence. In a paper published in Nature in December of 2005, entitled: “A Direct Test of E = mc” [1], author Simon Rainville et al. demonstrated the results of an experiment in which the fundamental process of neutron capture by nuclei of sulfur and silicon results in gamma radiation the energy content of which matches precisely the quantity ∆mc. The authors claimed that the experiment represents “the most precise direct test of the famous equation”. It seems that the physics community has totally forgotten that Einstein made two separate conclusions concerning the concept of mass-energy equivalence in his famous paper of 1905. The first conclusion predicts that the kinetic energy of a particle is numerically equiv-