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Einstein’s famous formula E=mc² says that mass and energy can turn into each other. It was first published by H. Poincare. Einstein published an alternate derivation that was corrected and improved by M. Planck. E stands for [[energy]], m is [[mass]], and c is the [[speed of light]]. So, if you increase the energy of a substance, for example by heating it, it gains a minute amount of mass. It was later realized that if you split an atom apart, as in a nuclear explosion, it loses a tiny amount of mass and you release a huge amount of [[energy]].   

Einstein’s famous formula E=mc² says that mass and energy can turn into each other. It was first published by H. Poincare. Einstein published an alternate derivation that was corrected and improved by M. Planck. E stands for [[energy]], m is [[mass]], and c is the [[speed of light]]. So, if you increase the energy of a substance, for example by heating it, it gains a minute amount of mass. It was later realized that if you split an atom apart, as in a nuclear explosion, it loses a tiny amount of mass and you release a huge amount of [[energy]].   

The connection E=mc² to nuclear energy is not as direct as pop culture sometimes represents. Einstein did not discover the huge energy available from nuclear reactions. Early workers in radioactivity, such as Ernest Rutherford, understood clearly that the natural radioactive decay of radium released quantities of energy that could not be explained by chemistry, and were much larger than those of chemical reactions. Neither did Einstein originate the key idea that made nuclear energy a possible weapon or a practical energy source. That was Leo Szilard, who acknowledged having been inspired by a 1914 H. G. Wells novel. Szilard discovered or invented the chain reaction (and patented it). What Einstein did was to popularize the formula E=mc², which was then used by others to help measure the release of energy.

The connection E=mc² to nuclear energy is not as direct as pop culture sometimes represents. Einstein did not discover the huge energy available from nuclear reactions. Early workers in radioactivity, such as Ernest Rutherford, understood clearly that the natural radioactive decay of radium released quantities of energy that could not be explained by chemistry, and were much larger than those of chemical reactions. Neither did Einstein originate the key idea that made nuclear energy a possible weapon or a practical energy source. That was Leo Szilard, who acknowledged having been inspired by a 1914 H. G. Wells novel. Szilard discovered or invented the chain reaction (and patented it). However, other people recognized the relation between Einstein's explanation of the E=mc² formula and chain reactions. Einstein explained that matter releasing energy is also losing mass.

Energy binds together the parts of an [[atom]], including the [[nucleus]]. The nucleus of an atom is tiny, but very little mass could release a huge amount of energy. When one nucleus splits apart, it splits other nuclei around it. This is called a [[chain reaction]].

Energy binds together the parts of an [[atom]], including the [[nucleus]]. The nucleus of an atom is tiny, but very little mass could release a huge amount of energy. When one nucleus splits apart, it splits other nuclei around it. This is called a [[chain reaction]].