The discovery and synthesis of new chemical elements by nuclear transmutation, and their production in the necessary quantities to allow study of their properties, was carried out in nuclear explosive device testing. For example, the discovery of the short-lived einsteinium and fermium, both created under the intense neutron flux environment within thermonuclear explosions, followed the first Teller–Ulam thermonuclear device test—Ivy Mike. The rapid capture of so many neutrons required in the synthesis of einsteinium would provide the needed direct experimental confirmation of the so-called r-process, the multiple neutron absorptions needed to explain the cosmic nucleosynthesis (production) of all chemical elements heavier than nickel on the periodic table in supernova explosions, before beta decay, with the r-process explaining the existence of many stable elements in the universe.