Hans Bethe Dies; Nobel Prize Winner Worked on A-Bomb
Martin Weil
Washington Post Staff Writer
Tuesday, March 8, 2005; Page B06

Hans Bethe, a scrupulously open-minded Nobel Prize winner who was perhaps the last survivor of the scientific titans who created nuclear physics and nuclear weapons, died March 5 at his home in Ithaca, N.Y., near Cornell University. He was 98.

His wife, Rose, daughter of a famed German university professor, said he died of congestive heart failure.

Dr. Bethe's Nobel Prize, awarded in 1967, came for work that stirred the imagination: He explained with pencil and paper how starlight is produced and what makes the sun shine.

What he described in detail in the 1930s were thermonuclear reactions of a kind that would later make possible the hydrogen bomb.

Dr. Bethe, a man viewed as a genius by colleagues and co-workers who were themselves regarded as among the most brilliant figures of their time, was also a principal figure in the development of the atom bomb, which ended World War II.

At Los Alamos, the secret New Mexico laboratory where the A-bomb was designed and built during the war, Dr. Bethe, esteemed for his knowledge and his reliability, was named to head the theoretical division.

After having met him in Europe as a young man, Edward Teller, known as the father of the hydrogen bomb, said Dr. Bethe had "the most comprehensive knowledge of theoretical physics that I had ever encountered."

Among the luminaries of 20th-century physics, Dr. Bethe was acknowledged to be in the front rank, serving as teacher, colleague and friend, and as a beacon in some of the moral confusions that sometimes accompanied their accomplishments.

The celebrated Richard Feynman worked for him at Los Alamos and studied with him at Cornell. Dr. Bethe testified for J. Robert Oppenheimer, who headed the atom bomb project, at Oppenheimer's security hearing; he gave a eulogy at Oppenheimer's 1967 funeral.

A participant in the postwar public debate over weapons policy, he appeared able to take strong stands without alienating his friends on the other side, and without depriving them of credit for their abilities and achievements.

He was widely regarded as the conscience of the nuclear science community.

When he first spoke in favor of limits on bomb testing, his impeccable reputation gave immediate credibility to that position.

He was also considered one of the most persuasive opponents of many of the schemes proposed in the 1980s to provide a shield against nuclear-armed missiles.

Nuclear physics, which was to seize the popular imagination in the second half of the 20th century, was in its infancy in the 1930s, when Dr. Bethe, in a literal sense, wrote the book on it.

The three long articles he produced in the late 1930s were the definitive guide for those probing the mysteries of the field. The articles, taken together, were known familiarly as "The Bethe Bible."

Like his wife, Hans Albrecht Bethe ( pronounced, BAY-tuh) was descended from an academic family. He was born July, 2, 1906, in Strasbourg, in Alsace-Lorraine, an area that had long been a zone of contention between France and Germany.

University professors had been in his family tree for generations. His father was a physiologist, and his mother and grandmother were professors' children.

After a secondary education in Frankfurt, at a school named for the poet Goethe, Dr. Bethe went on to the University of Frankfurt and then obtained a PhD at the University of Munich. This degree was conferred in 1928, at the time when physics was in ferment over the development of quantum mechanics, a revolutionary way of describing nature at its most elemental levels.

Seizing upon the possibilities of this new doctrine, he applied it before the 1920s had ended to some of the perplexing problems of the behavior of electrons as they bounce around among the atoms making up crystals.

He taught physics in Frankfurt, then in Stuttgart. He lectured in Munich and worked under pioneering nuclear physicist Sir Ernest Rutherford at Britain's Cambridge University. He also came in contact with Enrico Fermi and Niels Bohr, other figures from the physics pantheon.

His career appeared to reflect in part the academic inclinations of his ancestors. In the 1930s, another aspect of his ancestry helped determine the course of his life. Hitler was coming to power in Germany, and Dr. Bethe's mother was Jewish.

By 1935 he was at Cornell, where he would remain for the next 70 years and which he would help to rapidly become one of the East Coast's centers of physics.

He was often described as careful, meticulous, methodical, even austere in his work habits. Colleagues said that he prepared his masterful summary of nuclear physics by sitting in a room at a desk.

At one end of his desk was a stack of blank paper. Hour by hour, day after day, he took a sheet from the stack, covered it with words and equations, and deposited it on the other end of the desk.

Thus was written the "Bethe Bible," which appeared in a publication called the Reviews of Modern Physics.

Teller said it contained everything then known about nuclear physics -- which, he said, meant everything that Bethe knew.

About this time, Bethe and another scientist worked out in detail the process of nuclear fusion by which the sun generates its energy, producing heat and light.

He also elucidated a somewhat different mechanism by which some stars give their light. The multistage process known as the carbon cycle, required about six weeks for him to delineate. Although it has been said that many of his accomplishments merited it, this was the one that won him the Nobel Prize.

His students at Cornell recalled his patience, warmth and booming laugh. Not only that, but 70 years ago, nuclear scientists knew the delights of road trips.

In 1937, an important physics conference was being held at Stanford University. Teller and his wife went with Bethe and his spouse. According to Teller, "we all piled into Hans's car and drove across the nation."

Dr. Bethe became an American citizen in 1941, and the next year was among the handful of top scientists invited by Oppenheimer to Berkeley, Calif., for discussions on designing an atomic bomb.

"The fission bomb had to be done," Dr. Bethe later told a biographer, "because the Germans were presumably doing it."

This led to the creation of Los Alamos, where Dr. Bethe, as head of the theoretical division, led some of the world's best physicists in the complex calculations that were essential to building a workable bomb. Later, scientists would gather to watch him compete with Feynman in computation contests.

After the war, he returned to the academic world, appearing to hold the position that the bomb already built should be sufficient to maintain peace. He rejected Teller's early pleas to return to Los Alamos to work on the more powerful thermonuclear weapon.

Eventually, however, he did work on it, after being persuaded of its necessity. Once described as a dove, he told an interviewer, as quoted in a newspaper, that a better description would be "a tough dove."

He sought to avoid taking what he perceived as extremist positions in the arms control debates of the 1950s, and, ever the pragmatist, worked to develop blast detection systems that could be used to enforce bans on testing. He saw possible value in the use of fission to generate electricity.

He served on the President's Science Advisory Committee from 1956 to 1964 and received the government's Fermi Award.

Serene and energetic, he kept active as he grew older. At the age of 93, he gave three lectures to neighbors at an Ithaca retirement community. The topic was quantum theory.

In addition to his wife, survivors include two children.