Carl A. Bauer (1916–2019)

Carl A. Bauer died on Monday the 12th of August, 2019.

The astronomer Carl August Bauer, of State College, Pennsylvania, was born on November 10, 1916, on a farm in Kansas, and died on August 12, 2019, at the age of 102 and 9 months. He was the son of Frederick and Victoria (Lehmann) Bauer. He spent his boyhood in Wichita, Kansas. In 1941 he married Grace Marie Brunsvold. Carl and Grace had three daughters, Cynthia, Millicent, and Deborah. Carl was predeceased by his daughter Millicent in 1976, and his wife in 1980. Carl had three sisters Frances, Elsie, and Irene and two brothers Ernest and Harold, all of whom preceded him in death. His brother Harold was a radio operator on the U.S. Arizona and was killed at Pearl Harbor in 1941.

Carl graduated from Wichita [Kansas] High School East in 1935. After working for the American Optical Company for over a year, he attended the University of Minnesota in Minneapolis and received a BA in 1941. Then he entered the University of Chicago and did his graduate studies and research at Yerkes Observatory in Williams Bay, Wisconsin, where he received a master's degree in astronomy in 1944. Next he taught physics, astronomy, and mathematics at North Dakota State University in Fargo, North Dakota, and at Indiana University in Bloomington, Indiana. In 1945 he entered Harvard University in the Astronomy Department and received a doctorate in 1949. The title of his dissertation was: “On the Age and Origin of Meteorites.” His doctoral supervisor was Fred Whipple, famous for his “dirty snowball” model of comet nuclei.

Following studies at Harvard, Bauer taught astronomy at the University of Michigan in Ann Arbor. After leaving Michigan, he taught navigation at Harvard and then in 1951 he joined the Physics Department at Penn State. He was the first professionally trained astronomer at Penn State, where he organized the first undergraduate program in astronomy. In the following years, he was pleased to see the program develop into a separate department, with a first-rate research program in astronomy. He observed extensively with the world's largest refracting telescope, the 40-inch telescope at Yerkes Observatory, and with the 82-inch reflecting telescope at the McDonald Observatory on Mt. Locke in western Texas, which was the world’s second largest reflecting telescope at the time of its dedication in 1939. Most of this work involved the spectroscopic study of stars, especially the stars 13 Ceti and W Serpentis, both of which are peculiar spectroscopic binary stars. At Harvard he specialized in the study of meteorites and comets. Bauer's most important scientific contribution was his discovery that most of the helium in meteorites was produced by the action of cosmic radiation during the eons when they were in space orbiting the Sun. The discovery led to a complete revision of the assigned ages and past history of meteorites and asteroids. Previously it was believed that the helium in meteorites was formed by the radioactive decay of uranium and thorium. In 1959 and 1960 Carl measured the amount of helium-3 and helium-4 in 43 metallic meteorites and interpreted the results. In this work he used the mass spectrometer of the renowned physicist, Dr. A. O. Nier, at the University of Minnesota. As an undergraduate at that university, Bauer was taught atomic physics by Dr. Nier.

Carl Bauer was a member of the American Astronomical Society, a fellow of the American Association for the Advancement of Science, a member of the International Astronomical Union, a fellow of the Meteoritical Society, and a member of the scientific organization Sigma Xi. He was listed in American Men of Science, Who's Who in the Midwest, and Leaders in Education. He enjoyed gardening, storytelling, poetry, woodworking, mathematics, and science. Bauer said, he “wasn't the smartest, but he was persistent, lucky, and happy.”

Carl Bauer is survived by his daughter Cynthia Bauer-Levy and her husband Robert Levy, his daughter Deborah Gabriel and her husband John Gabriel, his grandchildren Ona Gabriel Feinberg and Alexandra Gabriel. Ona and her husband Gregory Feinberg have three children (Carl’s great-grandchildren), Lilian, Henry, and Evan. In recent years, Carl lost most of his relatives, friends, and associates, but filled this gap with many new and kind friends.