William Coblentz
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William Weber Coblentz (November 20, 1873 – September 15, 1962) 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 ...
notable for his contributions to
infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
radiometry and spectroscopy.


Early life, education, and employment

William Coblentz was born in North Lima, Ohio to parents of German and Swiss descent. His mother (Catherine) died when Coblentz was just under three, leaving him temporarily with a family of just his younger brother (Oscar) and their father (David). However, the father remarried about 2 years later, and Coblentz appears to have admired his second mother (Amelia). Throughout Coblentz's childhood and adolescence, his family lived on farms, but apparently were never able to buy one of their own. The family's extremely modest circumstances led to a somewhat-delayed education for Coblentz, who did not finish high school (Youngstown, Ohio) until 1896, when he was 22 years old. Coblentz entered the
Case School of Applied Science The Case School of Engineering is the engineering school at Case Western Reserve University in Cleveland, Ohio, USA. It traces its roots to the 1880 founding of the Case School of Applied Science. It became the Case Institute of Technology in 1947 ...
, now Case Western Reserve University in the fall of 1896, and received his Bachelor of Science degree in physics in June, 1900. He went on to earn MS (1901) and PhD (1903) degrees from
Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...
in Ithaca, New York, staying two years beyond his doctoral time by working as a Research Fellow with support from the Carnegie Institution. In the spring of 1905, Coblentz accepted a position with the newly founded
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 ...
(now the National Institute of Standards and Technology, NIST) in Washington, DC, where he spent his entire career. In 1905 he founded the Bureau's radiometry section, and headed it for 40 years until his retirement in 1945.


Scientific work

During the course of a long and productive career, Coblentz made many scientific contributions both of a pure and applied nature. Bibliographies of his work show that he had hundreds of scientific publications, talks, and abstracts to his credit. He received a total of ten patents during his lifetime, the first being US Patent 1,077,219 for a
solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.
invention to convert sunlight to electricity. Coblentz's first publication, "Some Optical Properties of Iodine", was based on his PhD research. On acquiring his doctorate, he soon began publishing regularly on problems related to infrared (IR) radiation, both those concerning spectroscopy and those concerning radiometry. For example, Coblentz was among the first, if not the very first, to verify Planck's Law.


Infrared studies

When Coblentz entered Cornell University, infrared spectroscopy was in what today would be considered an extremely primitive state. As a young Cornell researcher, Coblentz assembled and calibrated his own IR equipment, and extended the range of IR measurements to longer wavelengths than had ever been reached. By 1905 he had acquired hundreds of spectra by tedious point-by-point measurements with a prism instrument of his own construction. These were published in 1905 with large fold-outs charts (not available in the later reprints), and tables of wavelengths at which various materials absorbed IR light. While such a massive spectral compilation itself was something of a ''tour de force'', it is perhaps not the most important part of Coblentz's 1905 book. Instead, that honor probably goes to his generalization that certain molecular groupings, or functional groups in modern parlance, appeared to absorb specific and characteristic IR wavelengths. In time this would allow scientists to use a molecule's IR spectrum as a type of molecular fingerprint. This generalization had been hinted at in earlier work by others, but not with such a large amount of supporting data as Coblentz presented. Today, IR spectra are used in thousands of laboratories around the globe by scientists in many fields. As an aside, Coblentz's early work on molecular spectra was not given the eager reception that hindsight might suggest. The reasons are numerous and have been explored by several authors.


Astronomical studies

Coblentz had a long interest in astronomical problems. In 1913, he developed
thermopile detectors A thermopile is an electronic device that converts thermal energy into electrical energy. It is composed of several thermocouples connected usually in series or, less commonly, in parallel. Such a device works on the principle of the thermoelec ...
and used them at Lick Observatory to measure IR radiation from 110 stars, and the planets Mars, Venus, and Jupiter. In this work he was assisted by
Seth Nicholson Seth Barnes Nicholson (November 12, 1891 – July 2, 1963) was an American astronomer. He worked at the Lick observatory in California, and is known for discovering several moons of Jupiter in the 20th century. Nicholson was born in Springfield, ...
, later of the Mt. Wilson Observatory. Extending this work, Coblentz and
Carl Lampland Carl Otto Lampland (December 29, 1873 – December 14, 1951) was an American astronomer. He was involved with both of the Lowell Observatory solar system projects, observations of the planet Mars and the search for Planet X. Biography ...
, of the Lowell Observatory, measured large differences between the day and night temperatures on
Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...
, which implied a thin Martian atmosphere. For his applications of IR detectors to astronomy, Coblentz is regarded as the founder of astronomical
infrared spectroscopy Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) is the measurement of the interaction of infrared radiation with matter by absorption, emission, or reflection. It is used to study and identify chemical substances or function ...
. In recognition of his astronomical contributions, craters on the moon and Mars were named after him by the
International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
. Coblentz also made observations of solar eclipses, and published papers describing his work.


Other research

An inspection of Coblentz's bibliography shows that from about 1930 his research turned more toward measurements involving the ultraviolet (UV) region and away from infrared work. Much of this research had a distinctly bio-medical slant, such as his investigations of ultraviolet therapy (1938) and the production of skin cancer by UV exposure (1948). Although Coblentz is remembered today mainly for his contributions to physics and astronomy, he also had interests in bioluminescence, atmospheric ozone, and, perhaps surprisingly, parapsychology. He appears to have brought the same energy to the latter field as he did to his other areas of interest.


Honors

Coblentz was elected a member of the National Academy of Sciences in 1930. Among the awards Coblentz received were the 1911
Howard N. Potts Medal The Howard N. Potts Medal was one of The Franklin Institute Awards for science and engineering award presented by the Franklin Institute of Philadelphia, Pennsylvania. It is named for Howard N. Potts. The first Howard N. Potts Medal was awarded in ...
from the Franklin Institute, the 1920 Janssen Medal from the French Academy of Sciences, and the 1937
Rumford Prize Founded in 1796, the Rumford Prize, awarded by the American Academy of Arts and Sciences, is one of the oldest scientific prizes in the United States. The prize recognizes contributions by scientists to the fields of heat and light. These terms ...
from the American Academy of Arts and Sciences. In 1945, shortly after retiring, Coblentz received the
Frederic Ives Medal The Frederic Ives Medal is the highest award of the Optical Society, recognizing overall distinction in optics. The prize was established in 1928 by Herbert E. Ives in honor of his father, Frederic Ives. Initially awarded every two years, it has be ...
from the
Optical Society of America Optica (formerly known as The Optical Society (OSA) and before that as the Optical Society of America) is a professional society of individuals and companies with an interest in optics and photonics. It publishes journals and organizes conference ...
. The Coblentz Society, dedicated to the understanding and application of vibrational spectroscopy, is named in his honor, as is the Coblentz Medal. Coblentz was given membership card number 1 from the Society. Coblentz died just before his 1905 work on infrared spectroscopy was reprinted, nearly 60 years after its first publication.


Family and personal life

In his autobiography, ''From the Life of a Researcher'' (1951), William Coblentz described his typical day as long hours of laboratory research followed by evenings spent on data analysis and writing papers. This left little time for socializing, and so it is not unexpected that Coblentz was over 50 before ever marrying. He wed Catherine Emma Cate of Vermont on June 10, 1924, and it is said that they spent their honeymoon in Flagstaff, Arizona while Coblentz was at the Lowell Observatory measuring planetary temperatures.
Catherine Cate Coblentz Catherine Cate Coblentz (June 5, 1897 – May 30, 1951) was an American writer, best known for her children's books in the 1930s and 1940s. She was a Lewis Carroll Shelf Award and Newbery Honor laureate. Life and work Born in Hardwick, Vermon ...
achieved success as a writer of children's book, worked for a time at the National Bureau of Standards, and was instrumental in raising money to build the Cleveland Park Neighborhood Library in Washington, DC. William Coblentz reportedly was plagued by periods of poor health, but he lived nearly 90 years. He is buried in
Rock Creek Cemetery Rock Creek Cemetery is an cemetery with a natural and rolling landscape located at Rock Creek Church Road, NW, and Webster Street, NW, off Hawaii Avenue, NE, in the Petworth neighborhood of Washington, D.C., United States. It is across the stre ...
in Washington, DC alongside his wife and an infant daughter.


References


Further reading

*
A Physical Study of the Firefly
by William W. Coblentz, 1912 * ''Man's Place in a Superphysical World'', by William W. Coblentz, 1955 (concerning parapsychology) * ''Journal of the Optical Society of America'', 1936, volume 36, number 2, pp. 61 – 71 (The presentation ceremony, and Coblentz's accompanying lecture, for the Ives Medal, along with a list of Coblentz's scientific publications.) * ''Applied Optics'' (November, 1963), commemorative issue with extensive material on Coblentz's scientific work * Coblentz, W. W
"Present Status of the Determination of the Constant of Total Radiation from a Black Body,"
''Bulletin of the Bureau of Standards'' 12 (553-582) 1916. Copies of most of Coblentz's books are listed as being in the libraries of the University of Maryland and the American Institute of Physics, both in College Park, Maryland (USA), not far from where Coblentz lived, worked, and died.


External links


The Coblentz SocietyNational Academy of Sciences Biographical Memoir
{{DEFAULTSORT:Coblentz, William Weber 1873 births 1962 deaths American astronomers American physicists Cornell University alumni People from Mahoning County, Ohio Burials at Rock Creek Cemetery Howard N. Potts Medal recipients Members of the United States National Academy of Sciences