Staff Biographies

Philip Morrison

On July 16, 1945, at 5:29:45 a.m. Mountain Wartime in Alamogordo, New Mexico, Manhattan Project physicist Philip Morrison witnessed the detonation of the world's first atomic bomb. Monitoring the blast from a position some ten miles from ground zero, Morrison wrote:

"Immediately after this brilliant flash, which was somewhat blinding, I observed through the welding glass, centered at the direction of the tower, an enormous brilliant disk of white light. The disk was a true white in color, even through the welding glass, which makes the sun's disk distinctly deep green."

Moving Beyond Trinity's Success
For Morrison, the success of the test that affected the lives of so many people also influenced the direction of his work. Shortly after the Trinity event, Morrison was sent to Tinian Island in the Pacific to help assemble the nuclear components of the implosion weapon, codenamed Fat Man, for use against Japan.

This task was serious work for this 30-year-old physicist, who was born in Somerville, New Jersey, in 1915. Morrison earned his PhD in theoretical physics in 1940 from the University of California at Berkeley, where he studied under J. Robert Oppenheimer, who would become the wartime leader of Los Alamos. He then went on to teach at San Francisco State College and later at the University of Illinois.

Joining the Chicago Physicists
While at the University of Illinois, Morrison was invited by one of his fellow Berkeley graduate students to visit the University of Chicago's Metallurgical Laboratory. Within a few weeks of his visit, Morrison took a position, first as a research associate and later as a group leader at the Met Lab, where he became "an adept neutron engineer, testing again and again detailed mock-ups of the huge reactors to be built in Hanford, Washington, along the Columbia River."

The Manhattan Project work at Los Alamos had become more and more urgent by the middle of 1944, and many scientists, including Morrison, transferred to Los Alamos to help with the research and development of the wartime atomic weapons. There he began to work in the G (Gadget) Division, which had overall responsibility for developing the implosion weapon, named "Fat Man." The other device, the uranium gun weapon, was named "Little Boy."

Assembling the Trinity Device
By the spring of 1945, the rush was on for last-minute tests on the assembly of these two weapons being developed at Los Alamos. Unlike Little Boy, Fat Man proved to be more complicated and caused scientists to worry about whether it would work. To deal with one slice of this concern, a two-man team, called the "G-Engineers," was established to carry out the final design and assembly of the implosion weapon's pit assembly. Morrison along with Marshall Holloway became this two-man team.

As noted in Critical Assembly: A Technical History of Los Alamos during the Oppenheimer Years, 1943-45, "Morrison and Holloway were responsible for the final readiness of the implosion bomb, including the procurement, fabrication, and testing of all components from the inside of the high explosives to the outside of the initiator, which was at the center of the bomb."

Meeting President Truman's Schedule
Rushing through the last days of the Trinity program to assemble the implosion device, many scientists and researchers wondered if it would actually work. There was an additional source of stress, which did not involve any technical concerns. President Truman, who was scheduled to meet Stalin at Potsdam, wanted to tell Stalin of a very powerful weapon the U.S. had developed. It was crucial, therefore, that a successful test be completed before the Potsdam meeting, even though forecasters had advised that the best weather would come after that date.

With July 16 set as the definite testing date, it was Morrison and Holloway's job to insert the plutonium core into the high-explosive sphere of the Trinity device during the afternoon of the actual testing day. Once they began, their task took on a note of high drama when the plug of active material that they had to insert became stuck in the opening.

As Morrison's colleague remembered:

We knew damn well it should have [fit in the hole] because the uranium had been in [the assembly] before.... I believe I was the one who suggested, "Look just let it stick there for a few minutes, and the heat will be conducted away by the rest of the pit," and in less than a minute it just fell in and that crisis was over.

Assembling the Nagasaki Weapon
Shortly after the success at Trinity, Morrison made the long trip to Tinian Island and performed the same task on the Fat Man unit that actually would be dropped in combat on Nagasaki on August 9th. The evening before the Nagasaki mission, Morrison and fellow Los Alamos physicists Luis Alvarez and Robert Serber wrote a letter to a former Berkeley colleague, Professor Ryokichi Sagane, a professor of physics at the University of Tokyo. The letter stated, "It was obvious that we could build as many more [bombs] as might need to end the war by force."

Dropping a Letter and a Bomb
Alvarez, in particular, worried that Japan might gamble that the United States had only two atomic bombs. Morrison edited the letter, which was attached along with two carbon copies to the parachute gauges to be dropped the next day with one of the parachuted diagnostic canisters during the combat strike. Although the letter was found later, it never reached Professor Sagane

When the war came to an end after the two atomic bombings in Nagasaki and Hiroshima on August 9 and 12, respectively, the United States sent a contingent of scientists into Japan to assess the damage caused by Little Boy and Fat Man. As part of this team, Morrison spent several weeks analyzing the ravages of war.

Morrison returned home at the end of September, but before he left Los Alamos permanently in October 1946, he directed the work on the world's first fast plutonium reactor, which was given the codename Clementine by Morrison because of the reactor's location "in a cavern, in a canyon...."

Revealing the Mysteries of Los Alamos
During the months right after the war, Morrison performed another, less-official duty. From 1943 until the end of the war, the people of Santa Fe and the surrounding area had been kept in the dark about the frenzy of activity going on up the hill in Los Alamos. Once the secrecy ban was lifted in December of 1945, as Los Alamos resident Bernice Brode has recalled in Reminiscences of Los Alamos, 1943-45, "We had a grand debut into Santa Fe society."

Brode explained that a committee of Santa Fe citizens arranged a special gathering at the Museum of Anthropology, whose exhibits were replaced by a display of pictures of the atomic experiments and the two bombings. Enrico Fermi set up a demonstration and lecture, and Morrison stood on the stairs of the museum hallway, describing the damage of the Nagasaki and Hiroshima bombings and expressing the hope that some program of international control of atomic weapons would result.

Once the scientists revealed the unclassified details of the Manhattan Project and especially the mysteries of life in Los Alamos, their neighbors in the surrounding area began to plan parties and invite many of the scientists to talk to the guests about the secret wartime program. For scientists not used to the limelight, these events became a bit uncomfortable, though the Los Alamos experts did share their insights until they began to shun the spotlight and the snowy trips between Los Alamos and Santa Fe that winter.

Turning to Cosmic and Astrophysics Adventures
After leaving Los Alamos, Morrison returned to academic life, serving on the faculties at Cornell and the Massachusetts Institute of Technology. Though he continued working in nuclear physics into the 1950s, his research interests eventually turned to the cosmic rays and high-energy astrophysics.

Perhaps Morrison's most significant contribution to astrophysics occurred in 1959 when he and fellow Cornell physicist Giuseppe Cocconi published the article "Searching for Interstellar Communications" in the September edition of Nature. In that paper, Morrison and Cocconi speculated about the possible existence of other life in the cosmos and suggested that the best way to detect any such life was through the use of radio waves. The two authors chose radio waves because these waves can be created with very little power and because they can travel vast distances.

The publication of the Morrison and Cocconi paper led directly to the establishment of the Search for Extraterrestrial Intelligence, or SETI, and eventually in 1984 to the founding of the SETI Institute in California, which, according to its purpose statement, "conducts scientific research and educational programs to explore, understand, and explain the origin, nature, and prevalence of life in the universe." SETI.org

Focusing on Science Education Though the search for extraterrestrial life could occupy a lifetime, Morrison diversified from astrophysics and has dedicated a tremendous amount of time to science education, written over a dozen books including Powers of Ten, been a book reviewer for Scientific American, and a producer of the PBS series "The Ring of Truth."

Like so many of his fellow Los Alamos scientists, Philip Morrison never retired from his efforts to increase the understanding of so many facets of science for so many people.