Edward Purdy Ney (October 28, 1920 – July 9, 1996) was an American physicist who made major contributions to cosmic ray research, atmospheric physics, heliophysics, and infrared astronomy. He was a discoverer of cosmic ray heavy nuclei and of solar proton events. He pioneered the use of high-altitude balloons for scientific investigations and helped to develop procedures and equipment that underlie modern scientific ballooning. He was one of the first researchers to put experiments aboard spacecraft.
In 1963, Ney became one of the first infrared astronomers. He founded O'Brien Observatory, where he and his colleagues discovered that certain stars are surrounded by grains of carbon and silicate minerals and established that these grains, from which planets are formed, are ubiquitous in circumstellar winds and regions of star formation.
Early life Ney's father, Otto Fred Ney and mother, Jessamine Purdy Ney, lived in Waukon, Iowa. However, in October 1920, his mother went to Minneapolis, Minnesota, where Ney was delivered by Caesarean section. After elementary school, he attended Waukon High School, where he developed an interest in science and mathematics that was encouraged by Coach Howard B. Moffitt, who taught several of his courses and later became an administrator at the University of Iowa.
Career In 1938, Ney began undergraduate studies at the University of Minnesota, where he became acquainted with Professor Alfred O. C. Nier, who was an expert in mass spectrometry. Soon, Nier recruited him to work in the spectroscopy laboratory for 35 cents per hour. In February 1940, Nier prepared a tiny but pure sample of Uranium-235, which he mailed to Columbia University, where John R. Dunning and his team proved that this isotope was responsible for nuclear fission, rather than the more abundant Uranium-238. This finding was a crucial step in the development of the atomic bomb. That summer, Ney and Robert Thompson prepared a larger sample of Uranium-235, which provided material for further important tests. Later, he helped Nier design and test mass spectrographs that were replicated for extensive use in the Manhattan Project.
Graduate studies in Virginia In June 1942, after graduating with a B.S. degree in physics, Ney married June Felsing. They had four children: Judy, John, Arthur, and William. That year, Ney took his bride and two of Nier's mass spectrographs to Charlottesville, Virginia, where he began graduate studies with Jesse Beams at the University of Virginia. Ney brought experience and equipment that contributed significantly to Beams's wartime project to develop gas centrifuges for separation of uranium isotopes.
With Beams as his thesis advisor, Ney measured the self-diffusion coefficient of uranium hexafluoride. At the time, his results were classified, but in 1947, they were published in the Physical Review. In 1946, Ney received his Ph.D. in physics and became an assistant professor at the University of Virginia. With Beams and Leland Swoddy, he began an underground cosmic ray experiment in Endless Caverns near New Market, Virginia.
Return to Minnesota John T. Tate was an influential professor of physics at the University of Minnesota, who was Nier's mentor and editor of the Physical Review. After the war, he recognized the research potential of large plastic balloons, which had been invented by Jean Piccard and were being manufactured at the General Mills Laboratories in the Como neighborhood of Minneapolis. Here, Otto C. Winzen used polyethylene to make balloons whose performance at high altitudes was better than the cellophane ones developed by Piccard. In 1947, because of Ney's interest in cosmic rays, Tate offered him a position as assistant professor, which was immediately accepted. Except for a sabbatical and two brief leaves of absence, Ney spent the rest of his life at Minnesota.
Discovery of heavy cosmic ray nuclei Back in Minneapolis, Ney met Frank Oppenheimer and Edward J. Lofgren, who had both arrived about a year earlier. In response to Tate's initiative, these three decided to use balloons to study primary cosmic rays at the top of the atmosphere. At first, they focused on developing cloud chambers small enough to fly on balloons, but soon realized that nuclear emulsions offer a more portable way to detect energetic particles. To take charge of emulsion work, they enlisted a graduate student, Phyllis S. Freier, as the fourth member of their group. Later, she became a renowned professor. In 1948, the Minnesota group collaborated with Bernard Peters and Helmut L. Bradt, of the University of Rochester, to launch a balloon flight carrying a cloud chamber and emulsions. This flight gave evidence for heavy nuclei among the cosmic rays. More specifically, the researchers discovered that, in addition to Hydrogen nuclei (protons), primary cosmic rays contain substantial numbers of fast moving nuclei of elements from helium to iron.
In ordinary matter, atoms of these elements consist of a nucleus surrounded by a cloud of electrons, but when the nuclei arrive as cosmic rays, they are devoid of electrons, because of collisions with atoms in interstellar matter. In both emulsions and cloud chambers, these "stripped" heavy nuclei leave an unmistakable track, which is much denser and "hairier" than that of protons, and whose characteristics make it possible to determine their atomic number. In further flights, the group showed that the abundances of elements in cosmic rays are similar to those found on Earth and in stars. These results had a major impact, for they showed that studies of cosmic radiation could play a significant role in astrophysics.
Shortly after these discoveries, Lofgren left for California to build the Bevatron. In 1949, Oppenheimer was forced to resign from the Minnesota faculty, because he had concealed his prewar membership in the Communist Party USA. That year, John R. Winckler joined Minnesota's cosmic ray group.
In 1950, with the aid of a cloud chamber that contained lead plates, Ney, together with Charles Critchfield and graduate student Sophie Oleksa, searched for primary cosmic ray electrons. They did not find them, but in 1960, James Earl, who joined the Minnesota group in 1958, used similar apparatus to discover a small primary electron component.
During the decade from 1950 to 1960, Ney's cosmic ray research shifted away from cloud chambers toward emulsions. However, his graduate students used counter controlled cloud chambers to make significant advances in electronic instrumentation for the detection and analysis of cosmic rays. Specifically, in 1954, John Linsley used a cloud chamber triggered by a cherenkov detector to study the charge distribution of heavy nuclei, and in 1955, Frank McDonald used one triggered by a scintillation counter for a similar purpose. Later, McDonald combined these two electronic detectors into a balloon instrument that served as a prototype for devices carried on many spacecraft.
Balloon technology
Although early plastic balloons performed spectacularly in a few cases, there were dangerous mishaps during launch and many unexplained failures in flight. Ney realized that this unreliability was due to inadequate engineering and a fundamental lack of understanding of balloon physics. In response, he collaborated with Critchfield and Winckler to carry out a project entitled "Research and Development in the Field of High Altitude Plastic Balloons", which was sponsored by the US Army, Navy, and Air Force under a contract with the Office of Naval Research, Nonr-710 (01), which was in force from December 1951 until August 1956.
During the Cold War, the United States sponsored several heavily funded and top secret attempts to carry out surveillance of the Soviet Union by means of balloon overflights. These included: Project Mogul, Project Moby Dick, and Project Genetrix. In July 1958, responding to the disappointing results of these efforts and to the deployment of the Lockheed U-2, President Eisenhower ordered an end to balloon surveillance. Because the secret programs made use of information from the Minnesota balloon project, it too was secret, but all its materials were declassified in 1958.
While the project was active, Ney and his coworkers carried out 313 major or experimental balloon flights, published 16 technical reports, and patented approximately 20 inventions. The final report lists 62 major innovations and achievements. The innovations include the duct appendix, the natural shape balloon, the Minnesota launch system, and the tetroon balloon design. The last achievement listed was the post-project flight of a mylar tetroon on September 7, 1956, which reached a maximum height of 145,000 feet (44,000 m) over Minneapolis. At the time, this was a record altitude for balloons, and there was considerable press coverage of the flight. Most of the project's balloons were launched at the University of Minnesota Airport in New Brighton, Minnesota. They were among more than 1000 flights launched here from 1948 until the airport was devastated by a tornado on May 6, 1965.
Key personnel of the project were: Raymond W. Maas and William F. Huch, who provided engineering expertise, Rudolph B. Thorness, who was in charge of the physics machine shop, Robert L. Howard, who ran the electronics shop, and Leland S. Bohl, who worked on the project while earning his Ph.D. under Ney. Many of their names appear as authors not only of patents and technical reports, but also of scientific publications.
In spite of its secrecy, many of the project's balloons carried instruments for open scientific research. For example, from January 20, 1953, until February 4, 1953, with Winzen Research, Inc, the project launched 13 flights at Pyote Air Force Base in Texas. Several of these carried packages for cosmic ray research, one of which was designated as "ballast". These were Skyhook flights, which is the generic term used by the Office of Naval Research to designate balloon flights whose primary objectives were scientific, rather than military. Some milestones of more than 1500 Skyhook flights are: the first Skyhook launch (1947), the first shipboard launch (1949), the Rockoon program (1952), the tetroon record flight of September 1956, Stratoscope (1957 - 1971), and Skyhook Churchill (1959 - 1976).
In 1960, the National Center for Atmospheric Research was established. On October 17, 1961, its panel on scientific balloons met to select a permanent launch site for balloon operations. Members of this panel, whose chairman was Verner E. Suomi, were Ney, Charles B. Moore, Alvin Howell, James K. Angell, J. Allen Hynek, and Martin Schwarzschild, who was the prime mover behind Stratoscope. They chose Palestine, Texas, where the National Scientific Balloon Facility (NSBF) was created in 1962. Since then, thousands of balloons have been launched there, and it has served as the base for flight expeditions all over the world.
The Minnesota balloon project pioneered procedures and equipment used in Skyhook, NSBF, and the crewed flights of Projects Stratolab and Manhigh. These include launch methods, design of reliable balloons, knowledge of atmospheric structure, and reliable instrumentation for flight control and tracking.
Atmospheric physics