 Later, he revised this opinion on the strength of compelling evidence advanced by Fred Hoyle and others, that elements heavier than lithium are largely produced in thermonuclear reactions in stars and in supernovae.Gamow formulated a set of coupled differential equations describing his proposed process and assigned, as a PhD dissertation topic, his graduate student Ralph Alpher the task of solving the equations numerically.These results of Gamow and Alpher appeared in 1948 as the Alpher–Bethe–Gamow paper.