Theodore Lyman IV (; November 23, 1874 – October 11, 1954) was an American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

and spectroscopist, born in

Boston Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...

. He graduated from

Harvard Harvard University is a private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher lear ...

in 1897, from which he also received his Ph.D. in 1900.

Career

Lyman became an assistant professor in

physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

at Harvard, where he remained, becoming full

professor Professor (commonly abbreviated as Prof.) is an Academy, academic rank at university, universities and other tertiary education, post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin ...

in 1917, and where he was also director of the Jefferson Physical Laboratory (1908–17). He made important studies in phenomena connected with

diffraction grating In optics, a diffraction grating is an optical grating with a periodic structure that diffraction, diffracts light, or another type of electromagnetic radiation, into several beams traveling in different directions (i.e., different diffractio ...

s, on the

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

s of vacuum

ultraviolet light Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of th ...

discovered by

Victor Schumann Victor Schumann (21 December 1841 – 1 September 1913) was a physicist and spectroscopist who in 1893 discovered the vacuum ultraviolet. Schumann studied the extreme ultraviolet region of the electromagnetic spectrum. For this, he used a Pr ...

and also on the properties of light of extremely short

, on all of which he contributed valuable papers to the literature of

in the proceedings of scientific societies.

Military service

During

World War I World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

he served in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

with the

American Expeditionary Force The American Expeditionary Forces (AEF) was a formation of the United States Armed Forces on the Western Front (World War I), Western Front during World War I, composed mostly of units from the United States Army, U.S. Army. The AEF was establis ...

, holding the rank of major of engineers.

Legacy/honors

* He was the

eponym An eponym is a noun after which or for which someone or something is, or is believed to be, named. Adjectives derived from the word ''eponym'' include ''eponymous'' and ''eponymic''. Eponyms are commonly used for time periods, places, innovati ...

of the Lyman series of spectral lines. * The crater Lyman on the far side of the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

is named after him. * He was elected to the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

in 1901. * He was elected to the United States

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

in 1917. * He was elected to the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

in 1918. * He was awarded the

Franklin Institute The Franklin Institute is a science museum and a center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and wikt:statesman, statesman Benjamin Franklin. It houses the Benjamin Franklin ...

Elliott Cresson Medal The Elliott Cresson Medal, also known as the Elliott Cresson Gold Medal, was the highest award given by the Franklin Institute. The award was established by Elliott Cresson, life member of the Franklin Institute, with $1,000 granted in 1848. Th ...

and the Frederic Ives Medal in 1931. * The Optical Society elected him an Honorary Member in 1941. * The Lyman Laboratory of Physics at Harvard University is named after him.

Affiliations

He became a hereditary member of the

Military Order of the Loyal Legion of the United States The Military Order of the Loyal Legion of the United States (MOLLUS), or, simply, the Loyal Legion, is a United States military order organized on April 15, 1865, by three veteran officers of the Union Army. The original membership was consisted ...

in succession to his father, Lieutenant Colonel Theodore Lyman III.

References

*
USGS Gazetteer of Planetary Nomenclature Feature Information
*193
Frederic Ives Medal

External links

National Academy of Sciences Biographical Memoir
{{DEFAULTSORT:Lyman, Theodore 1874 births 1954 deaths United States Army officers American military personnel of World War I Military personnel from Massachusetts Harvard University faculty Harvard University alumni Scientists from Boston American optical physicists American spectroscopists Hollis Chair of Mathematics and Natural Philosophy Members of the United States National Academy of Sciences Presidents of the American Physical Society Physicists from Massachusetts Members of the American Philosophical Society