Stirling Colgate

Stirling Colgate (born 1925) was America's premier diagnostician of thermonuclear weapons at the Lawrence Livermore National Laboratory in California. He was among the few that initially realized that the emissions of supernovae could have set off American satellites spying on the Soviet Union and spark a third World War. He also worked on one of the more controversial computer models of supernovae. Because much of his involvement with physics had been highly classified, current information on him is scarce.

Colgate attended Los Alamos Ranch School until 1942 when a military delegation along with input from Robert Oppenheimer and Ernest O. Lawrence decided to close the the school. Colgate was graduated without notice. Oppenheimer would take the lead and ultimately lead to the invention of the atomic bomb.

Colgate had extremely varied interests, spanning experimental and theoretical physics to vehicle machinery. The following year he attended Cornell University to study electric engineering. In 1944 Colgate enlisted in the merchant marine. After Hiroshima, the captain called upon him to "tell us what it means." At that time what he explained was strictly confidential, most of all the description of nuclear fission.

After being discharged in 1946, Colgate returned to Cornell University. He then completed a Bachelor of Science and a PhD in nuclear physics, taking up a position as postdoctoral fellow at Berkeley.

In 1952 he moved to Livermore National Laboratory. The laboratory had been recently created by Edward Teller with encouragement from the United States Air Force in order to compete with Los Alamos weapons research. For the purposes of developing a hydrogen bomb, Teller assigned Colgate to the diagnositc measurements for their nuclear tests.

Helping the Hydrogen Bomb

Colgate studied the radioactive products of an explosion which were scooped from the atmosphere by specially designed aircraft. His second job was measuring the range of energy of the neutrons and higher frequency gamma rays created by the nuclear tests.

Colgate's work required him to shuffle between Livermore and Los Alamos. Upon one trip to Los Alamos he met Subrahmanyan Chandrasekhar, whom he worked with again almost ten years later.

In the 1950s Colgate was in charge of thousands during the Bravo test, the first deliverable thermonuclear bomb. Upon this success, Teller encouraged Colgate to begin research on thermonuclear fusion and plasma physics.

Into Astrophysics

In 1956 Colgate and colleague Montgomery Johnson were recruited to investigate the resultant radiation and debris from a hydrogen bomb explosion in space. The US government had considered adding space as the fourth plane of warfare. They found that the catastrophic amount of X-rays and gamma-rays would liken the impact to a supernova. This involved a fair amount of research into astrophysics, which decidedly ignited his interest. Colgate and Johnson's first attempts to understand the mechanism of a supernova began with determining the actual cause of one. They assumed that "a shockwave from the core bounce smashes into nuclear ash plummeting inwards due to the inward tug of gravity". The shockwave would turn this matter around, heating it up, causing the supernova. However this turned out to be wrong, as Richard White used computer simulations to show that the shockwave would not be strong enough to trigger the event. Colgate and White began developing models of stars on the verge of collapse. White wrote a computer program combining software used to design bombs with equations of state for a star. In discussion with a friend, Colgate found that neutrinos can develop degeneracy pressure. This degeneracy pressure aided the shockwave in blowing off the outer shells of an expiring star, leaving a neutron star behind. While this research helped validate Chandrasekhar's work on limits, neutron stars were still purely hypothetical.

In 1959, upon advice of Los Alamos and Livermore National Laboratories, State Department recruited Colgate as the scientific consultant on nuclear test ban negotiations in Geneva. It was here that he proposed the detection of nuclear testing by use of spy satellites. However he also raised the possibility of false alarm caused by supernovae.

Despite encouragement by Teller to follow up on the detonation of the 50 megaton Czar bomb which the Soviet Union had just detonated in breach of the Soviet-American moratorium on nuclear weapons, Colgate decided to continue his prior research on supernovae.

In 1966 his research with Johnson and White finally emerged in a paper carefully edited by Chandrasekhar.

Quote

*"I was always enamored with explosives, and eventually I graduated to dynamite and then nuclear bombs."

References

* Miller, A 2005, "Empire of Stars", Little, Brown, Great Britain.