American physicist · 1913–2004
Philip Abelson
Philip Abelson co-discovered neptunium in 1940, the first element beyond uranium.
How Neptunium was found
Abelson had been studying uranium fission products and was ready to analyse the 2.3-day activity Edwin McMillan had found. In a few days at Berkeley in May 1940 he showed chemically that it was not a rare earth or any known element.
McMillan and Abelson published the discovery of element 93 in June 1940. Its rapid publication worried officials, and soon afterwards research on fission became secret.
Shared the credit
The discovery is credited jointly to these scientists.
Life and career
Born 1913 · Died 2004
Abelson was born in Tacoma, Washington. During the war he developed liquid thermal diffusion, a method of enriching uranium that supplied part of the material for the first atomic bomb.
He later directed the Geophysical Laboratory of the Carnegie Institution and edited the journal Science from 1962 to 1984.
Also known for
- Liquid thermal diffusion for enriching uranium
- Editor of Science, 1962–1984
Discovered in the same era
Other elements identified within ten years of 1940.