In his later years, he advocated controversial technological solutions to military and civilian problems, including a plan to excavate an artificial harbor in Alaska using a thermonuclear explosive in what was called Project Chariot, and Ronald Reagan's Strategic Defense Initiative.

In collaboration with Stephen Brunauer and Paul Hugh Emmett, Teller also made an important contribution to surface physics and chemistry: the so-called Brunauer–Emmett–Teller (BET) isotherm.

On the advice of the well-known Caltech aerodynamicist and fellow Hungarian émigré Theodore von Kármán, Teller collaborated with his friend Hans Bethe in developing a theory of shock-wave propagation.

[32] In 1942, Teller was invited to be part of Robert Oppenheimer's summer planning seminar at the University of California, Berkeley, on the origins of the Manhattan Project, the US effort to develop the first nuclear weapons.

At the Berkeley session, Teller diverted discussion from the fission weapon to the possibility of a fusion weapon—what he called the "Super", an early conception of the hydrogen bomb.

Oppenheimer had him investigate unusual approaches to building fission weapons, such as autocatalysis, in which the efficiency of the bomb would increase as the nuclear chain reaction progressed, but proved to be impractical.

These too were originally low-priority tasks, but the discovery of spontaneous fission in plutonium by Emilio Segrè's group gave the implosion bomb increased importance.

[48][49][50][51] Teller was one of the few scientists to watch (with eye protection) the Trinity nuclear test in July 1945, rather than follow orders to lie on the ground with backs turned.

[56]Teller later learned of Oppenheimer's solicitation and his role in the Interim Committee's decision to drop the bombs, having secretly endorsed an immediate military use of the new weapons.

[61][62] At the end of the conference, in spite of opposition by some members such as Robert Serber, Teller submitted an optimistic report in which he said that a hydrogen bomb was feasible, and that further work should be encouraged on its development.

The model of Teller's "classical Super" was so uncertain that Oppenheimer would later say that he wished the Russians were building their own hydrogen bomb based on that design, as it would almost certainly delay their progress on it.

[61] By 1949, Soviet-backed governments had already begun seizing control throughout Eastern Europe, forming such puppet states as the Hungarian People's Republic in Teller's homeland of Hungary, where much of his family still lived, on August 20, 1949.

He insisted on involving more theorists, but many of Teller's prominent colleagues, like Fermi and Oppenheimer, were sure that the project of the H-bomb was technically infeasible and politically undesirable.

In 1951 Teller and Ulam made a breakthrough, and invented a new design, proposed in a classified March 1951 paper, On Heterocatalytic Detonations I: Hydrodynamic Lenses and Radiation Mirrors, for a practical megaton-range H-bomb.

Thomas Powers writes that "of course the bomb designers all knew the truth, and many considered Teller the lowest, most contemptible kind of offender in the world of science, a stealer of credit".

[82] Sundial was the codename of one of two massive bombs planned for testing by the University of California Radiation Laboratory, Livermore Branch as part of a classified American weapons project In the early 1950s Edward Teller proposed project Sundial at a meeting of the General Advisory Committee of the Atomic Energy Commission, the bomb was intended to have a yield of 10 gigatons of TNT, while its counterpart, Gnomon, was intended to have a yield of 1 gigaton.

He additionally testified that Oppenheimer's direction of Los Alamos was "a very outstanding achievement" both as a scientist and an administrator, lauding his "very quick mind" and that he made "just a most wonderful and excellent director".

[83] Historian Richard Rhodes said that in his opinion it was already a foregone conclusion that Oppenheimer would have his security clearance revoked by then AEC chairman Lewis Strauss, regardless of Teller's testimony.

However, as Teller's testimony was the most damning, he was singled out and blamed for the hearing's ruling, losing friends due to it, such as Robert Christy, who refused to shake his hand in one infamous incident.

This yield, roughly thirty times that of the Hiroshima bomb, was enough for Chief of Naval Operations Admiral Arleigh Burke, who was present in person, and Navy strategic missile development shifted from Jupiter to Polaris by the end of the year.

At an address to the membership of the American Chemical Society in December 1957, Teller warned that the large amount of carbon-based fuel that had been burnt since the mid-19th century was increasing the concentration of carbon dioxide in the atmosphere, which would "act in the same way as a greenhouse and will raise the temperature at the surface", and that he had calculated that if the concentration of carbon dioxide in the atmosphere increased by 10% "an appreciable part of the polar ice might melt".

[98] Other scientists criticized the project as being potentially unsafe for the local wildlife and the Inupiat people living near the designated area, who were not officially told of the plan until March 1960.

[101] A related experiment which also had Teller's endorsement was a plan to extract oil from the tar sands in northern Alberta with nuclear explosions, titled Project Oilsands.

[105] In 1952, Teller and Oppenheimer had a long meeting with David Ben-Gurion in Tel Aviv, telling him that the best way to accumulate plutonium was to burn natural uranium in a nuclear reactor.

After the accident, Teller acted quickly to lobby in defence of nuclear energy, testifying to its safety and reliability, and soon after one flurry of activity suffered the attack.

I was there to refute some of that propaganda that Ralph Nader, Jane Fonda and their kind are spewing to the news media in their attempt to frighten people away from nuclear power.

[110]In the 1980s, Teller began a strong campaign for what was later called the Strategic Defense Initiative (SDI), derided by critics as "Star Wars", the concept of using ground and satellite-based lasers, particle beams and missiles to destroy incoming Soviet ICBMs.

[111] Scandal erupted when Teller (and his associate Lowell Wood) were accused of deliberately overselling the program and perhaps encouraging the dismissal of a laboratory director (Roy Woodruff) who had attempted to correct the error.

[117][118][119] In order to safeguard the earth, the theoretical 1 Gt device would weigh about 25–30 tons—light enough to be lifted on the Russian Energia rocket—and could be used to instantaneously vaporize a 1 km asteroid, or divert the paths of extinction event class asteroids (greater than 10 km in diameter) with a few months' notice; with 1-year notice, at an interception location no closer than Jupiter, it would also be capable of dealing with the even rarer short period comets which can come out of the Kuiper belt and transit past Earth orbit within 2 years.

[120] Teller's vigorous advocacy for strength through nuclear weapons, especially when so many of his wartime colleagues later expressed regret about the arms race, made him an easy target for the "mad scientist" stereotype.