David Wayne Allan (born September 25, 1936) is an American

atomic clock An atomic clock is a clock that measures time by monitoring the resonant frequency of atoms. It is based on atoms having different energy levels. Electron states in an atom are associated with different energy levels, and in transitions betwe ...

physicist and author of the

Allan variance The Allan variance (AVAR), also known as two-sample variance, is a measure of frequency stability in clocks, oscillators and amplifiers. It is named after David W. Allan and expressed mathematically as \sigma_y^2(\tau). The Allan deviation (ADE ...

, also known as the two-sample variance, a measure of

frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...

stability in

clock A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and t ...

s, oscillators and other applications. He worked for the

National Bureau of Standards The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical sci ...

in Colorado. Allan was born in born in Mapleton, Utah, on September 25, 1936. He studied physics at the

Brigham Young University Brigham Young University (BYU, sometimes referred to colloquially as The Y) is a private research university in Provo, Utah. It was founded in 1875 by religious leader Brigham Young and is sponsored by the Church of Jesus Christ of Latter-d ...

(B.S. 1960) and at the

University of Colorado The University of Colorado (CU) is a system of public universities in Colorado. It consists of four institutions: University of Colorado Boulder, University of Colorado Colorado Springs, University of Colorado Denver, and the University o ...

(M.S. 1965). From 1960 he was a physicist in the Time and Frequency Division of the

National Institute of Standards and Technology The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...

(then the National Bureau of Standards) in Boulder, and from 1979 was 1988 chief of the Time and Frequency Coordination Group. He retired in 1992 and lives in

Fountain Green, Utah Fountain Green is a city in Sanpete County, Utah, United States. The population was 1,071 at the 2010 census. History Fountain Green was originally called "Uintah Springs", and under the latter name settlement was made in 1859. A post office c ...

. Allan was a consultant for the

United Nations Development Programme The United Nations Development Programme (UNDP)french: Programme des Nations unies pour le développement, PNUD is a United Nations agency tasked with helping countries eliminate poverty and achieve sustainable economic growth and human dev ...

in New Delhi in 1981, and a guest scientist in the People's Republic of China in 1982. He is a

Mormon Mormons are a religious and cultural group related to Mormonism, the principal branch of the Latter Day Saint movement started by Joseph Smith in upstate New York during the 1820s. After Smith's death in 1844, the movement split into severa ...

. He has been married since 1959.

Awards

Allan received the Silver Medal of the Department of Commerce in 1968, and one of the IR-100 awards of '' Industrial Research'' magazine in 1976. He received the Rabi Award of the

IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operati ...

in 1984. In 1999 he was named an

honorary fellow Honorary titles (professor, reader, lecturer) in academia may be conferred on persons in recognition of contributions by a non-employee or by an employee beyond regular duties. This practice primarily exists in the UK and Germany, as well as in m ...

of the Institute of Navigation. In 2018 he received the Joseph F. Keithley Award in Instrumentation and Measurement of the Institute of Electrical and Electronics Engineers.

References

{{DEFAULTSORT:Allan, David Wayne Living people 21st-century American physicists Latter Day Saints from Colorado Brigham Young University alumni University of Colorado alumni 1936 births People from Mapleton, Utah People from Fountain Green, Utah Latter Day Saints from Utah