Percy Williams Bridgman

Percy Williams Bridgman (21 April 1882 – 20 August 1961) was an American physicist who received the 1946 Nobel Prize in Physics for his work on the physics of high pressures. He also wrote extensively on the scientific method and on other aspects of the philosophy of science.[2][3][4] The Bridgman effect and the Bridgman–Stockbarger technique are named after him.

Percy Williams Bridgman
Born21 April 1882
Cambridge, Massachusetts, United States
Died20 August 1961 (aged 79)
Cause of deathSuicide
NationalityUnited States
Alma materHarvard University
Known forHigh-pressure physics
Operational definition
AwardsRumford Prize (1917)
Elliott Cresson Medal (1932)
Comstock Prize in Physics (1933)
Nobel Prize in Physics (1946)
Fellow of the Royal Society (1949)[1]
Bingham Medal (1951)
Scientific career
InstitutionsHarvard University
Doctoral advisorWallace Clement Sabine
Doctoral studentsFrancis Birch
Gerald Holton
John C. Slater
John Hasbrouck Van Vleck


Early life

Known to family and friends as "Peter", Bridgman was born in Cambridge, Massachusetts, and grew up in nearby Auburndale, Massachusetts.[5]

Bridgman's parents were both born in New England. His father, Raymond Landon Bridgman, was "profoundly religious and idealistic" and worked as a newspaper reporter assigned to state politics. His mother, Mary Ann Maria Williams, was described as "more conventional, sprightly, and competitive".[5]

Bridgman attended both elementary and high school in Auburndale, where he excelled at competitions in the classroom, on the playground, and while playing chess. Described as both shy and proud, his home life consisted of family music, card games, and domestic and garden chores. The family was deeply religious; reading the Bible each morning and attending a Congregational Church.[5] However, Bridgman later became an atheist.[6]

Education and professional life

Bridgman entered Harvard University in 1900, and studied physics through to his Ph.D. From 1910 until his retirement, he taught at Harvard, becoming a full professor in 1919. In 1905, he began investigating the properties of matter under high pressure. A machinery malfunction led him to modify his pressure apparatus; the result was a new device enabling him to create pressures eventually exceeding 100,000 kgf/cm2 (10 GPa; 100,000 atmospheres). This was a huge improvement over previous machinery, which could achieve pressures of only 3,000 kgf/cm2 (0.3 GPa). This new apparatus led to an abundance of new findings, including a study of the compressibility, electric and thermal conductivity, tensile strength and viscosity of more than 100 different compounds. Bridgman is also known for his studies of electrical conduction in metals and properties of crystals. He developed the Bridgman seal and is the eponym for Bridgman's thermodynamic equations.

Bridgman made many improvements to his high-pressure apparatus over the years, and unsuccessfully attempted the synthesis of diamond many times.[7]

His philosophy of science book The Logic of Modern Physics (1927) advocated operationalism and coined the term operational definition. In 1938 he participated in the International Committee composed to organise the International Congresses for the Unity of Science.[8] He was also one of the 11 signatories to the Russell–Einstein Manifesto.

Home life and death

Percy Bridgman with wife and Gustaf VI Adolf of Sweden 1946
Bridgman with wife and Gustaf VI Adolf of Sweden in Stockholm im 1946

Bridgman married Olive Ware, of Hartford, Connecticut, in 1912. Ware's father, Edmund Asa Ware, was the founder and first president of Atlanta University. The couple had two children and were married for 50 years, living most of that time in Cambridge. The family also had a summer home in Randolph, New Hampshire, where Bridgman was known as a skilled mountain climber.[5]

Bridgman was a "penetrating analytical thinker" with a "fertile mechanical imagination" and exceptional manual dexterity. He was a skilled plumber and carpenter, known to shun the assistance of professionals in these matters. He was also fond of music and played the piano, and took pride in his flower and vegetable gardens.[5]

Bridgman committed suicide by gunshot after suffering from metastatic cancer for some time. His suicide note read in part, "It isn't decent for society to make a man do this thing himself. Probably this is the last day I will be able to do it myself."[9] Bridgman's words have been quoted by many in the assisted suicide debate.[10][11]

Honors and awards

Bridgman received Doctors, honoris causa from Stevens Institute (1934), Harvard (1939), Brooklyn Polytechnic (1941), Princeton (1950), Paris (1950), and Yale (1951). He received the Bingham Medal (1951) from the Society of Rheology, the Rumford Prize from the American Academy of Arts and Sciences (1919), the Elliott Cresson Medal (1932) from the Franklin Institute, the Gold Medal from Bakhuys Roozeboom Fund (founder Hendrik Willem Bakhuis Roozeboom) (1933) from the Royal Netherlands Academy of Arts and Sciences,[12] and the Comstock Prize (1933) of the National Academy of Sciences.[13]

Bridgman was a member of the American Physical Society and was its President in 1942. He was also a member of the American Association for the Advancement of Science, the American Academy of Arts and Sciences, the American Philosophical Society, and the National Academy of Sciences. He was a Foreign Member of the Royal Society and Honorary Fellow of the Physical Society of London.

The Percy W. Bridgman House, in Massachusetts, is a U.S. National Historic Landmark designated in 1975.[14]

In 2014, the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association (IMA) approved the name bridgmanite for perovskite-structured (Mg,Fe)SiO3,[15] the Earth's most abundant mineral,[16] in honor of his high-pressure research.


  • — (1922). Dimensional Analysis. New Haven: Yale University Press. OCLC 840631.
  • — (1925). A Condensed Collection of Thermodynamics Formulas. Cambridge, Massachusetts: Harvard University Press. OCLC 594940689.
  • — (1927). The Logic of Modern Physics. New York: Macmillan. OCLC 17522325.[17] Online excerpt.
  • — (1934). The Thermodynamics of Electrical Phenomena in Metals. New York: Macmillan.
  • — (1936). The Nature of Physical Theory. Dover. OCLC 1298653.
  • — (1938). The Intelligent Individual and Society. New York: MacMillan. OCLC 1488461.
  • — (1941). The Nature of Thermodynamics. Cambridge, Massachusetts: Harvard University Press. ISBN 9780844605128. OCLC 4614803.
  • — (1949). The Physics of High Pressure. London: G. Bell. OCLC 8122603.
  • — (1950). Reflections of a Physicist. New York: Philosophical Library. OCLC 583047.[18]
  • — (1952). Studies in large plastic flow and fracture: with special emphasis on the effects of hydrostatic pressure. New York: McGraw-Hill. OCLC 7435297.
  • — (1959). The Way Things Are. Cambridge, Massachusetts: Harvard University Press. ISBN 9780674948303. OCLC 40803473.
  • — (1961) [First published separately in 1925 and 1934]. Thermodynamics of Electrical Phenomena in Metals and a Condensed Collection of Thermodynamic Formulas. New Haven: Macmillan. OCLC 610252150.
  • — (1962). A Sophisticate's Primer of Relativity. Middletown, Conn: Wesleyan University Press. OCLC 530615.
  • — (1964). Collected experimental papers. Cambridge, Massachusetts: Harvard University Pres. OCLC 372237.

See also


  1. ^ Newitt, D. M. (1962). "Percy Williams Bridgman 1882–1961". Biographical Memoirs of Fellows of the Royal Society. 8: 26–40. doi:10.1098/rsbm.1962.0003.
  2. ^ "Percy W. Bridgman". Physics Today. 14 (10): 78. 1961. doi:10.1063/1.3057180.
  3. ^ Bridgman, P. (1914). "A Complete Collection of Thermodynamic Formulas". Physical Review. 3 (4): 273–281. Bibcode:1914PhRv....3..273B. doi:10.1103/PhysRev.3.273.
  4. ^ Bridgman, P. W. (1956). "Probability, Logic, and ESP". Science. 123 (3184): 15–17. Bibcode:1956Sci...123...15B. doi:10.1126/science.123.3184.15. PMID 13281470.
  5. ^ a b c d e Kemble, Edwin C.; Birch, Francis (1970). Percy Williams Bridgman – 1882—1961 (PDF). National Academy of Sciences. pp. 25, 26, 27.
  6. ^ Ray Monk (2013). Robert Oppenheimer: A Life Inside the Center. Random House LLC. ISBN 9780385504133. In many ways they were opposites; Kemble, the theorist, was a devout Christian, while Bridgman, the experimentalist, was a strident atheist.
  7. ^ Hazen, Robert (1999), The Diamond Makers, Cambridge: Cambridge University Press, ISBN 0-521-65474-2
  8. ^ Neurath, Otto (1938). "Unified Science as Encyclopedic Integration". International Encyclopedia of Unified Science. 1 (1): 1–27.
  9. ^ Nuland, Sherwin. How We Die: Reflections on Life's Final Chapter. Vintage Press, 1995. ISBN 0-679-74244-1.
  10. ^ Ayn Rand Institute discussion on assisted suicide.; retrieved 2012-01-28.
  11. ^ Euthanasia Research and Guidance Organization. (2003-06-13); retrieved 2012-01-28.
  12. ^ "Bakhuys Roozeboom Fund laureates". Royal Netherlands Academy of Arts and Sciences. Archived from the original on 7 August 2011. Retrieved 13 January 2011.
  13. ^ "Comstock Prize in Physics". National Academy of Sciences. Archived from the original on December 29, 2010. Retrieved February 13, 2011.
  14. ^ James Sheire (February 1975), National Register of Historic Places Inventory-Nomination: Percy Bridgman House/Bridgman House-Buckingham School (PDF), National Park Service, retrieved 2009-06-22 and Accompanying one photo, exterior, from 1975 (519 KB)
  15. ^ Page on bridgmanite,; retrieved 2014-06-03.
  16. ^ Murakami, M.; Sinogeikiin S.V.; Hellwig H.; Bass J.D.; Li J. (2007). "Sound velocity of MgSiO3 perovskite to Mbar pressure" (PDF). Earth and Planetary Science Letters. Elsevier. 256: 47–54. Bibcode:2007E&PSL.256...47M. doi:10.1016/j.epsl.2007.01.011. Retrieved June 7, 2012.
  17. ^ Kovarik, A. F. (1929). "Review: The Logic of Modern Physics by P. W. Bridgman" (PDF). Bull. Amer. Math. Soc. 35 (3): 412–413. doi:10.1090/s0002-9904-1929-04767-0.
  18. ^ Riepe, D. (1950). "Book Review: Reflections of a Physicist, by P. W. Bridgman". Popular Astronomy. 58: 367–368. Bibcode:1950PA.....58..367R.

Further reading

  • Walter, Maila L., 1991. Science and Cultural Crisis: An Intellectual Biography of Percy Williams Bridgman (1882–1961). Stanford Univ. Press.
  • McMillan, Paul F (2005), "Pressing on: the legacy of Percy W. Bridgman.", Nature Materials (published Oct 2005), 4 (10), pp. 715–8, Bibcode:2005NatMa...4..715M, doi:10.1038/nmat1488, PMID 16195758

External links

Academic offices
Preceded by
Theodore Lyman
Hollis Chair of Mathematics and Natural Philosophy
Succeeded by
John Hasbrouck Van Vleck
Bingham Medal

The Bingham Medal is an annual award for outstanding contributions to the field of rheology awarded at the Annual Meeting of The Society of Rheology. It was instituted in 1948 by the society to commemorate Eugene C. Bingham (1878-1945).


Bridgman is a surname, and may refer to:

David Bridgman, Australian architect

Elijah Coleman Bridgman (1801–1861), American missionary in China

Frederick Arthur Bridgman (1847-1928), American artist

George Bridgman (1865-1943), anatomist and artist

Jon Bridgman, American historian

Laura Bridgman (1829-1889), deaf-blind American

Margaret Bridgman, former Canadian member of parliament

Mel Bridgman, ice hockey player

Percy Williams Bridgman (1882–1961), American physicist and 1946 Nobel laureate

Bridgman's thermodynamic equations

In thermodynamics, Bridgman's thermodynamic equations are a basic set of thermodynamic equations, derived using a method of generating a large number of thermodynamic identities involving a number of thermodynamic quantities. The equations are named after the American physicist Percy Williams Bridgman. (See also the exact differential article for general differential relationships).

The extensive variables of the system are fundamental. Only the entropy S , the volume V and the four most common thermodynamic potentials will be considered. The four most common thermodynamic potentials are:

The first derivatives of the internal energy with respect to its (extensive) natural variables S and V yields the intensive parameters of the system - The pressure P and the temperature T . For a simple system in which the particle numbers are constant, the second derivatives of the thermodynamic potentials can all be expressed in terms of only three material properties

Bridgman's equations are a series of relationships between all of the above quantities.

Bridgman seal

A Bridgman seal, invented by and named after Percy Williams Bridgman, can be used to seal a pressure chamber and compress its contents to high pressures (up to 40,000 MPa), without the seal leaking and releasing the pressure

A cylindrical driving piston is mounted within a cylindrical channel that is closed at its far end. This piston presses against a hard steel ring, followed by a softer steel ring, and then a ring of more viscous or elastic material such as rubber, copper or soap stone, all within the channel. These three intermediate stages provide an inner cylinder, and the third stage bears on a specially shaped final steel piston that applies the force to pressurise material held at the end of the outer, enclosing channel. The final piston consists of a wider portion that fills the main channel, and a narrower cylindrical extension that leads back through the inner channel formed by the three ring-shaped intermediate stages, ending within the hard steel ring without making direct contact with the driving piston. This arrangement ensures that higher pressures create tighter seals that resist any leakage from the material at the end, since the pressure within the last and softest ring is greater than that in the material at the end.This arrangement has much in common with the earlier de Bange breech obturator system used to prevent the escape of gasses from breech loading artillery, whether inspired by that or independently invented, with the important further feature that Bridgman's system does not merely resist the escape of material under pressure while stationary, it applies that pressure by movement within the pressurising equipment.

Bridgman's previous pressurizing arrangement, a screw with a 2-m spanner, allowed him to get pressures of up to 400 MPa; the Bridgman seal allowed pressures up to 40,000 MPa. These are typical pressures expected in the Earth's internal structure. This advance allowed him to make many discoveries, including the high-pressure phases of ice (still known by the Bridgman nomenclature), high-pressure minerals, and novel high-pressure material properties. These discoveries were important in many fields of science and engineering. Bridgman won a Nobel Prize for his work.

Bridgman–Stockbarger technique

The Bridgman–Stockbarger technique is named after Harvard physicist Percy Williams Bridgman (1882-1961) and MIT physicist Donald C. Stockbarger (1895–1952). The technique includes two similar but distinct methods primarily used for growing boules (single crystal ingots), but which can be used for solidifying polycrystalline ingots as well.

The methods involve heating polycrystalline material above its melting point and slowly cooling it from one end of its container, where a seed crystal is located. A single crystal of the same crystallographic orientation as the seed material is grown on the seed and is progressively formed along the length of the container. The process can be carried out in a horizontal or vertical orientation, and usually involves a rotating crucible/ampoule to stir the melt.The Bridgman method is a popular way of producing certain semiconductor crystals such as gallium arsenide, for which the Czochralski process is more difficult. The process can reliably produce single crystal ingots, but does not necessarily result in uniform properties through the crystal.

The difference between the Bridgman technique and Stockbarger technique is subtle: While both methods utilize a temperature gradient and a moving crucible, the Bridgman technique utilizes the relatively uncontrolled gradient produced at the exit of the furnace; the Stockbarger technique introduces a baffle, or shelf, separating two coupled furnaces with temperatures above and below the freezing point. Stockbarger's modification of the Bridgman technique allows for better control over the temperature gradient at the melt/crystal interface.

When seed crystals are not employed as described above, polycrystalline ingots can be produced from a feedstock consisting of rods, chunks, or any irregularly shaped pieces once they are melted and allowed to re-solidify. The resultant microstructure of the ingots so obtained are characteristic of directionally solidified metals and alloys with their aligned grains.

A variant of the technique known as the horizontal directional solidification method or HDSM developed by Khachik Bagdasarov starting in the 1960s in the Soviet Union uses a flat-bottomed crucible with short sidewalls rather than an enclosed ampoule, and has been used to grow various large oxide crystals including Yb:YAG (a laser host crystal), and sapphire crystals 45 cm wide and over 1 meter long.


Ductility is a measure of a material's ability to undergo significant plastic deformation before rupture, which may be expressed as percent elongation or percent area reduction from a tensile test. According to Shigley's Mechanical Engineering Design (10th Ed.) significant denotes about 5.0 percent elongation (Section 5.3, p. 233). See also Eq. 2–12, p. 50 for definitions of percent elongation and percent area reduction. Ductility is often characterized by a material's ability to be stretched into a wire.

From examination of data in Tables A20, A21, A22, A23, and A24 in Shigley's Mechanical Engineering Design, 10th Edition, for both ductile and brittle materials, it is possible to postulate a broader quantifiable definition of ductility that does not rely on percent elongation alone. In general, a ductile material must have a measurable yield strength, at which unrecoverable plastic deformation begins (see Yield (engineering)), and also must satisfy one of the following conditions: either have an elongation to failure of at least 5%, or area reduction to rupture at least 20%, or true strain to rupture at least 10%.

Malleability, a similar property, is a material's ability to deform under compressive stress; this is often characterized by the material's ability to form a thin sheet by hammering or rolling. Both of these mechanical properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture. Also, these material properties are dependent on temperature and pressure (investigated by Percy Williams Bridgman as part of his Nobel Prize-winning work on high pressures).

Ductility and malleability are not always coextensive – for instance, while gold has high ductility and malleability, lead has low ductility but high malleability. The word ductility is sometimes used to encompass both types of plasticity.

Edmund Asa Ware

Edmund Asa Ware (December 22, 1837-September 25, 1885) was an American educator and the first president of Atlanta University, serving from 1869 to 1885.

Ware, son of Asa B. and Catharine (Slocum) Ware, was born December 22, 1837, in North Wrentham, now Norfolk, Mass, and entered College from Norwich, Connecticut, to which place his family had removed about 1852. He graduated from Yale College in 1863. For the two years next after graduation he taught in the Norwich Free Academy, where he had had his early education.

In September, 1865, he went to Nashville, Tennessee to assist in reorganizing the public schools, and thence a year later to Atlanta, Georgia, under the auspices of the American Missionary Association, as Superintendent of the Association's schools in that city and vicinity In December, 1866, he was licensed to preach, and from that time preached more or less frequently. He received August 1, 1867, from General Howard, the appointment of State Superintendent of Education for Georgia; and while thus acting interested himself in the establishment of an institution for the higher education for African-Americans. He thus became the President of the Board of Trustees as well as of the Faculty of the Atlanta University, which was chartered in 1867, and opened in 1869; and the remainder of his life was spent in its service.

He had lately returned from a visit to the mountains, to prepare for the opening of the school, and appeared in usual health; on the afternoon of September 25, 1885, he died suddenly of heart disease, in Atlanta, in the 48th year of his age.

He married November 10, 1869, Sarah J. Twichell of Plantsville, Connecticut, who survived him with three daughters and one son. One of their daughters, Olive, was married in 1912 to Percy Williams Bridgman, recipient of the 1946 Nobel Prize in Physics.

High pressure

In science and engineering the study of high pressure examines its effects on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. By high pressure is usually meant pressures of thousands (kilobars) or millions (megabars) of times atmospheric pressure (about 1 bar or 100,000 Pa).

Hollis Chair of Mathematics and Natural Philosophy

The Hollis Chair of Mathematics and Natural Philosophy is an endowed professorship established at Harvard College in 1727 by Thomas Hollis.The incumbents have been:

Isaac Greenwood (1727–1737)

John Winthrop (1737–1779)

Samuel Williams (1779–1789)

Samuel Webber (1789–1806)

John Farrar (1807–1838)

Joseph Lovering (1838–1888)

Benjamin Osgood Peirce (1888–1914)

Wallace Clement Sabine (1914–1919)


Theodore Lyman (1921–1926)

Percy Williams Bridgman (1926–1950)

John Hasbrouck Van Vleck (1951–1969)

Andrew Gleason (1969–1992)

Bertrand Halperin (1992-)

Index of philosophy of science articles

An index list of articles about the philosophy of science.

John Torrence Tate Sr.

John Torrence Tate Sr. (July 28, 1889 – May 27, 1950) was an American physicist noted for his editorship of Physical Review between 1926 and 1950. He is the father of mathematician John Torrence Tate Jr.

List of Fellows of the Royal Society elected in 1949

This page lists Fellows of the Royal Society elected in 1949.

List of rheologists

This is a list of notable rheologists.


Pascalization, bridgmanization, high pressure processing (HPP) or high hydrostatic pressure (HHP) processing is a method of preserving and sterilizing food, in which a product is processed under very high pressure, leading to the inactivation of certain microorganisms and enzymes in the food. HPP has a limited effect on covalent bonds within the food product, thus maintaining both the sensory and nutritional aspects of the product. The technique was named after Blaise Pascal, a French scientist of the 17th century whose work included detailing the effects of pressure on fluids. During pascalization, more than 50,000 pounds per square inch (340 MPa, 3.4 kbar) may be applied for around fifteen minutes, leading to the inactivation of yeast, mold, and bacteria. Pascalization is also known as bridgmanization, named for physicist Percy Williams Bridgman.


The English surname Percy, first taken by the House of Percy, Norman lords of Northumberland, derives from the village of Percy-en-Auge in Normandy. From there, it came into use as a given name. It is also a short form of the given name Percival, Perseus, etc.

Percy W. Bridgman House

The Percy W. Bridgman House is an historic house located at 10 Buckingham Place in Cambridge, Massachusetts. It is a National Historic Landmark, notable for its associations with Dr. Percy Williams Bridgman, a physicist, Nobel Prize winner, and Harvard University professor. It is now part of the Buckingham Browne & Nichols (BBN) Lower School campus.The house is an architecturally undistinguished 2​1⁄2 story house built about 1920 in a Neo-Rationalist style. At the time of its designation as a National Historic Landmark in 1975, the house had not been significantly altered since Dr. Bridgman's death in 1961. It was acquired by the BBN School not long after his death, which has used it for a variety of purposes, including as a faculty residence and lounge. It is used for school offices.

Percy Bridgman (1882–1961) was born in Cambridge, raised in Newton, and educated at Harvard. After receiving his Ph.D. in physics in 1908, he was invited to join the Harvard physics faculty, where he remained for the rest of his life. Bridgman's primary area of research was high pressure physics. He was awarded the Nobel Prize in Physics (the fifth American to be so honored) in 1946 for his development of equipment for advancing research in that field. He also wrote extensively on the epistemology of physics and the sciences, advancing ideas that evolved into the field of operations research during the 1940s. Bridgman moved into this house in 1928, and lived there for the rest of his life.

Scripta Mathematica

Scripta Mathematica was a quarterly journal published by Yeshiva University devoted to the philosophy, history, and expository treatment of mathematics. It was said to be, at its time, "the only mathematical magazine in the world edited by specialists for laymen."The journal was established in 1932 under the editorship of Jekuthiel Ginsburg, a professor of mathematics at Yeshiva University, and its first issue appeared in 1933 at a subscription price of three dollars per year. It ceased publication in 1973. Notable papers published in Scripta Mathematica included work by Nobelist Percy Williams Bridgman concerning the implications for physics of set-theoretic paradoxes, and Hermann Weyl's obituary of Emmy Noether.Some sources describe Scripta Mathematica as having been assigned ISSN 0036-9713 but it ceased publication prior to the establishment of the ISSN system.

The Logic of Modern Physics

The Logic of Modern Physics is a 1927 philosophy of science book by American physicist and Nobel laureate Percy Williams Bridgman. The book was widely read by scholars in the social sciences, in which it had a huge influence in the 1930s and 1940s, and its major influence on the field of psychology in particular surpassed even that on methodology in physics, for which it was originally intended. The book is notable for explicitly identifying, analyzing, and explaining operationalism for the first time, and coining the term operational definition.

Operationalism can be considered a variation on the positivist theme, and, arguably, a very powerful and influential one. Sir Arthur Eddington had discussed notions similar to operationalization before Bridgman, and pragmatic philosophers had also advanced solutions to the related ontological problems. Bridgman's formulation, however, became the most influential.

Theodore Lyman IV

Theodore Lyman IV (; November 23, 1874 – October 11, 1954) was a U.S. physicist and spectroscopist, born in Boston. He graduated from Harvard in 1897, from which he also received his Ph.D. in 1900.


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