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

U.S. The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

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 caus ...

and

spectroscopist Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter wav ...

, born in

Boston Boston (), officially the City of Boston, is the state capital and most populous city of the Commonwealth of Massachusetts, as well as the cultural and financial center of the New England region of the United States. It is the 24th- mo ...

. He graduated from

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

in 1897, from which he also received his

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is a ...

in 1900.

Career

Lyman became an assistant professor in

physics Physics is the natural science that studies matter, its 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 which r ...

at Harvard, where he remained, becoming full

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

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 component with a periodic structure that diffracts light into several beams travelling in different directions (i.e., different diffraction angles). The emerging coloration is a form of structura ...

s, on the

wavelength In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats. It is the distance between consecutive corresponding points of the same phase on the wave, such as two adjacent crests, tro ...

s of vacuum

ultraviolet light Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

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 wished to study the "Extreme Ultraviolet" region. For this, he used a prism and lenses in flu ...

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 (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

he served in

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

with the

American Expeditionary Force The American Expeditionary Forces (A. E. F.) was a formation of the United States Army on the Western Front of World War I. The A. E. F. was established on July 5, 1917, in France under the command of General John J. Pershing. It fought alon ...

, holding the rank of major of engineers.

Legacy/honors

* He was the

eponym An eponym is a person, a place, or a thing after whom or which someone or something is, or is believed to be, named. The adjectives which are derived from the word eponym include ''eponymous'' and ''eponymic''. Usage of the word The term ''epon ...

of the

Lyman series In physics and chemistry, the Lyman series is a hydrogen spectral series of transitions and resulting ultraviolet emission lines of the hydrogen atom as an electron goes from ''n'' ≥ 2 to ''n'' = 1 (where ''n'' is the principa ...

spectral lines A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to ident ...

. * The crater Lyman on the far side of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

is named after him. * He was awarded the

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

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. The ...

in 1931. * The

Lyman Laboratory of Physics The Lyman Laboratory of Physics (named for the physicist Theodore Lyman) is a building at Harvard University located between the Jefferson and Cruft Laboratories in the North Yard. It was built in the early 1930s, to a design by Coolidge, Shepley, ...

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 patriotic order, organized April 15, 1865, by three veteran officers of the Army. The original membership was composed of members ...

in succession to his father, Lieutenant Colonel

Theodore Lyman III Theodore Lyman III (August 23, 1833 – September 9, 1897) was a natural scientist, military staff officer during the American Civil War, and United States Representative from Massachusetts. Biography Lyman was born in Waltham, Massachusetts o ...

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 People from Boston American physicists Optical physicists Spectroscopists Hollis Chair of Mathematics and Natural Philosophy Members of the United States National Academy of Sciences Presidents of the American Physical Society