William Wallace Campbell (11 April 1862 – 14 June 1938) was an American astronomer, and director of Lick Observatory from 1900 to 1930. He specialized in spectroscopy.
He was born on a farm in Hancock county, Ohio, the son of Robert Wilson and Harriet Welsh Campbell. After a few years of local schooling he entered in 1882 the University of Michigan to study civil engineering, graduating Bachelor of Science in 1886. Whilst at university he developed his interest in astronomy when he read Simon Newcomb's Popular Astronomy.
After graduating he was appointed Professor of Mathematics at the University of Colorado but soon moved back to Michigan as an instructor in astronomy. In 1891 he was invited to work on spectroscopy at Lick Observatory in California. Campbell was a pioneer of astronomical spectroscopy and catalogued the radial velocities of stars. He was made a director of Lick Observatory from 1901 to 1930. In 1931 he accepted the rôle of president of the National Academy of Sciences in Washington (1931–1935).
He served as 10th President of the University of California from 1923 to 1930. He also served on the board of trustees for Science Service, now known as Society for Science & the Public, from 1923-1926. He served three terms as president of the Astronomical Society of the Pacific (in 1895, 1909 and 1918).
Dr Campbell took his own life at the age of 76 in San Francisco. He was mostly blind and suffering from bouts of aphasia. This was not only very frustrating to him, but he felt that it left him a burden to his family in terms of care and expense, according to notes he left behind at the time of his death. He had married Elizabeth Ballard Thompson in 1892; they had three sons.
Charles Frederick Crocker and William Henry Crocker financed numerous Lick-Crocker solar eclipse expeditions. Campbell led several of these expeditions.
- January 22, 1898 — Jeur, Maharashtra, India
- May 28, 1900 — Thomaston, GA
- August 30, 1905 — Alhama, Spain
- January 3, 1908 — Flint Island, Kiribati
- August 21, 1914 — Brovary, Ukraine
- June 8, 1918 — Goldendale, WA
September 21, 1922 - Wallal, Australia (The data Wallace obtained on this occasion provided further evidence supporting Albert Einstein's at-the-time new general theory of relativity. Wallace's party was part of an international expedition to Wallal, which included Dr. C.A. Chant, Mrs. Chant, their daughter Elizabeth and Dr. R.K. Young representing Canada.)
According to Looking Up, Dr. Campbell was an honorary member of the Royal Astronomical Society of Canada, but the details are not well understood. Campbell was first named in Society documents as a Corresponding Member in 1905. By 1931 he was listed as an Honorary Member.