energy generation in stars appear in the concepts describing nucleosynthesis, which arose in the 1940s, led by George Gamow and presented in a 2-page paper in 1948 as the Alpher–Bethe–Gamow paper. A complete concept of processes that make up cosmic nucleosynthesis was presented in the late 1950s by Burbidge, Burbidge, Fowler, and Hoyle, and by Cameron. Fowler is largely credited with initiating collaboration between astronomers, astrophysicists, and theoretical and experimental nuclear physicists, in a field that we now know as nuclear astrophysics (for which he won the 1983 Nobel Prize). During these same decades, Arthur Eddington and others were able to link the liberation of nuclear binding energy through such nuclear reactions to the structural equations of stars. These developments were not without curious deviations. Many notable physicists of the 19th century such as Mayer, Waterson, von Helmholtz, and Lord Kelvin, postulated that the Sun radiates thermal energy by converting gravitational potential energy into heat. Its lifetime as calculated from this assumption using the virial theorem, around 19 million years, was found inconsistent with the interpretation of geological records and the (then new) theory of biological evolution. Alternatively, if the Sun consisted entirely of a fossil fuel like coal, considering the rate of its thermal energy emission, its lifetime would be merely four or five thousand years, clearly inconsistent with records of human civilization. Basic concepts During cosmic times, nuclear reactions re-arrange the nucleons that were left behind from the big bang (in the form of isotopes of hydrogen and helium, and traces of lithium, beryllium, and boron) to other isotopes and elements as we find them today (see graph). The driver is a conversion of nuclear binding energy to exothermic energy, favoring nuclei with more binding of their nucleons - these are then lighter as their original components by the binding energy. The most tightly-bound nucleus from symmetric matter of neutrons and protons is 56Ni. The release of nuclear binding energy is what allows stars to shine for up to billions of years, and may disrupt stars in stellar explosions in case of violent reactions (such as 12C+12C fusion for thermonuclear supernova explosions). As matter is processed as such within stars and stellar explosions, some of the products are ejected from the nuclear-reaction site and end up in interstellar gas. Then, it may form new stars, and be processed further through nuclear reactions, in a cycle of matter. This