William David Coolidge
Encyclopedia
William David Coolidge was an American physicist
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

, who made major contributions to X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

 machines. He was the director of the General Electric Research Laboratory
General Electric Research Laboratory
General Electric Research Laboratory, the first industrial research facility in the United States, was established in 1900. This lab was home to the early technological breakthroughs of General Electric and created a research and development environment that set the standard for industrial...

 and a vice-president of the corporation. He was also famous for the invention of "ductile tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

", which is important for the incandescent light bulb.

Early years

Coolidge was born on a farm near Hudson
Hudson, Massachusetts
Hudson is a town in Middlesex County, Massachusetts, United States. The population was 19,063 at the 2010 census. The town is located in central Massachusetts, about a 40-minute drive, or about , west of Boston, and about a 20-minute drive, or about , northeast of Worcester.Before its...

, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

. He studied electrical engineering
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...

 from 1891 until 1896 at the Massachusetts Institute of Technology
Massachusetts Institute of Technology
The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...

 (MIT). After a year as a laboratory assistant, he went to Germany for further study and received his doctorate from the University of Leipzig
University of Leipzig
The University of Leipzig , located in Leipzig in the Free State of Saxony, Germany, is one of the oldest universities in the world and the second-oldest university in Germany...

. From 1899 to 1905 he was a research assistant to Arthur A. Noyes of the Chemistry Department at MIT.

Ductile tungsten

Coolidge went to work as a researcher at General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...

's new research laboratory in 1905, where he conducted experiments that led to the use of tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

 as filaments in light bulbs. He developed 'ductile tungsten', which could be more easily drawn into filaments, by purifying tungsten oxide. Starting in 1911, General Electric marketed lamps using the new metal and they soon became an important source of income for GE. He applied for and received a patent (US#1,082,933) for this 'invention' in 1913. However, in 1928 a US court ruled that his 1913 patent was not valid as an invention.

Improved X-ray tube

In 1913 he invented the Coolidge tube, an X-ray tube with an improved cathode
Cathode
A cathode is an electrode through which electric current flows out of a polarized electrical device. Mnemonic: CCD .Cathode polarity is not always negative...

 for use in X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

 machines that allowed for more intense visualization of deep-seated anatomy and tumors
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

. The Coolidge tube, which also utilized a tungsten
Tungsten
Tungsten , also known as wolfram , is a chemical element with the chemical symbol W and atomic number 74.A hard, rare metal under standard conditions when uncombined, tungsten is found naturally on Earth only in chemical compounds. It was identified as a new element in 1781, and first isolated as...

 filament, was a major development in the then-nascent medical specialty of radiology
Radiology
Radiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...

, and its basic design is still in use. He filed for patent in 1913 and finally it was granted as US Patent 1,203,495 in 1916.

Awards

The American Academy of Arts and Sciences
American Academy of Arts and Sciences
The American Academy of Arts and Sciences is an independent policy research center that conducts multidisciplinary studies of complex and emerging problems. The Academy’s elected members are leaders in the academic disciplines, the arts, business, and public affairs.James Bowdoin, John Adams, and...

 awarded Coolidge the Rumford Prize
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...

 in 1914. Coolidge was awarded the American Institute of Electrical Engineers
American Institute of Electrical Engineers
The American Institute of Electrical Engineers was a United States based organization of electrical engineers that existed between 1884 and 1963, when it merged with the Institute of Radio Engineers to form the Institute of Electrical and Electronics Engineers .- History :The 1884 founders of the...

 Edison Medal in 1927 For his contributions to the incandescent electric lighting and the X-rays art. He rejected this prestigious award in 1926 on the basis that his ductile tungsten patent (1913) was ruled by court as invalid. He was awarded the Howard N. Potts Medal
Howard N. Potts Medal
The Howard N. Potts Medal was a science and engineering award presented by the Franklin Institute, of Philadelphia, Pennsylvania, USA.Also see The Franklin Institute Awards.-Laureates:Following people received the Howard N. Potts Medal:...

 in 1926 and the Louis E. Levy Medal in 1927. Coolidge was awarded the Faraday Medal
Faraday Medal
The Faraday Medal is a medal awarded by the Institution of Electrical Engineers The bronze medal is awarded without restriction as regards nationality, country of...

 in 1939. He was awarded the Franklin Medal
Franklin Medal
The Franklin Medal was a science and engineering award presented by the Franklin Institute, of Philadelphia, PA, USA.-Laureates:*1915 - Thomas Alva Edison *1915 - Heike Kamerlingh Onnes *1916 - John J...

 in 1944. In 1975 he was elected to the National Inventors Hall of Fame
National Inventors Hall of Fame
The National Inventors Hall of Fame is a not-for-profit organization dedicated to recognizing, honoring and encouraging invention and creativity through the administration of its programs. The Hall of Fame honors the men and women responsible for the great technological advances that make human,...

, shortly before his death at age 101 in Schenectady
Schenectady, New York
Schenectady is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2010 census, the city had a population of 66,135...

, New York.

Later career

Coolidge became director of the GE research laboratory in 1932, and a vice-president of General Electric in 1940, until his retirement in 1944. He continued to consult for GE after retirement.

Patents

  • Coolidge, , Coolidge tube
  • Coolidge, , "X-ray tube
    X-ray tube
    An X-ray tube is a vacuum tube that produces X-rays. They are used in X-ray machines. X-rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light...

    "
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "Stereoscopic x-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray tube shield"
  • Coolidge, , "X-ray device"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus and method"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray apparatus"
  • Coolidge, , "X-ray device"
  • Coolidge, , "X-ray anode
    Anode
    An anode is an electrode through which electric current flows into a polarized electrical device. Mnemonic: ACID ....

    "
  • Coolidge, , "X-ray tube"
  • Coolidge, , "X-ray tube"
  • Coolidge, , "X-ray device"
  • Coolidge, , "X-ray device"

External links


  • John Anderson Miller, Yankee scientist: William David Coolidge, Mohawk Development Service, 1963 ISBN 0677651503
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