The need for a physical setting providing rapid neutron capture, which was known to almost certainly have a role in element formation, was also seen in a table of abundances of isotopes of heavy elements by Hans Suess and Harold Urey in 1956. Their abundance table revealed larger than average abundances of natural isotopes containing magic numbers of neutrons as well as abundance peaks about 10 amu lighter than stable nuclei containing magic numbers of neutrons which were also in abundance, suggesting that radioactive neutron-rich nuclei having the magic neutron numbers but roughly ten fewer protons were formed. These observations also implied that rapid neutron capture occurred faster than beta decay, and the resulting abundance peaks were caused by so-called waiting points at magic numbers. This process, rapid neutron capture by neutron-rich isotopes, became known as the r -process, whereas the s -process was named for its characteristic slow neutron capture. A table apportioning the heavy isotopes phenomenologically between s -process and r -process isotopes was published in 1957 in the B FH review paper, which named the r -process and outlined the physics that guides it. Alastair G. W. Cameron also published a smaller study about the r -process in the same year.