Does nature convert mass into energy?, Ralph Baiellein, Am. J. Phys. 75(4), April 2007
First I provide some history of how E = mc2 arose, establish what "mass" means in the context of the context of this relation, and present some aspects of how the relation can be understood. Then I address the question, Does E = mc2 mean that one can "convert mass into energy" and vice versa?