Percy Williams Bridgman (21 April 1882 – 20 August 1961) was an American physicist who won the 1946 Nobel Prizer 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.
Biography
Bridgman entered Harvard University in 1900, and studied physics through to his PhD. 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.
His philosophy of science book The Logic of Modern Physics (1927) advocated operationalism and coined the term operational definition. He was also one of the 11 signatories to the Russell-Einstein Manifesto.
Death
Bridgman committed suicide by gunshot after living with metastic 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." Bridgman's words have been quoted by many on both sides of the assisted suicide debate
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 Medal from the American Academy of Arts and Sciences, the Elliott Cresson Medal 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, and the Comstock Prize (1933) of the National Academy of Sciences. He 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 Historica Landmark designated in 1975.
http://en.wikipedia.org/wiki/Percy_Williams_Bridgman
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Operationalization
In research design, especially in psychology, social sciences, life sciences, and physics, operationalization is a process of defining the measurement of a phenomenon that is not directly measurable, though its existence is indicated by other phenomena. It is the process of defining a fuzzy concept so as to make the theoretical concept clearly distinguishable or measurable, and to understand it in terms of empirical observations. In a wider sense, it refers to the process of specifying the extension of a concept — describing what is and is not a part of that concept. For example, in medicine, the phenomenon of health might be operationalized by one or more indicators like body mass index or tobacco smoking. Thus, some phenomena are directly difficult to observe (i.e. they are latent), but their existence can be inferred by means of their observable effects.
The concept of operationalization was first presented by the British physicist N. R. Campbell in his 'Physics: The Elements' (Cambridge, 1920). This concept next spread to humanities and social sciences. It remains in use in physics.
History
Operationalization is used to specifically refer to the scientific practice of operationally defining, where even the most basic concepts are defined through the operations by which we measure them. This comes from the philosophy of science book The Logic of Modern Physics (1927), by Percu Williams Bridgman, whose methodological position is called operationalism.
Bridgman's theory was criticized because we measure "length" in various ways (e.g. it's impossible to use a measuring rod if we want to measure the distance to the Moon), "length" logically isn't one concept but many. Each concept is defined by the measuring operations used. Another example is the radius of a sphere, obtaining different values depending on the way it is measured (say, in metres and in millimeters). Bridgman said the concept is defined on the measurement. So the criticism is that we would end up with endless concepts, each defined by the things that measured the concept.
Bridgman notes that in the theory of relativity we see how a concept like "duration" can split into multiple different concepts. As part of the process of refining a physical theory, it may be found that what was one concept is, in fact, two or more distinct concepts. However, Bridgman proposes that if we only stick to operationally defined concepts, this will never happen.
Operationalization and Relativity
The practical 'operational definition' is generally understood as relating to the theoretical definitions that describe reality through the use of theory.
The importance of careful operationalization can perhaps be more clearly seen in the development of General Relativity. Einstein discovered that there were two operational definitions of "mass" being used by scientists: inertial, defined by applying a force and observing the acceleration, from Newton’s Second Law of Motion; and gravitational, defined by putting the object on a scale or balance. Previously, no one had paid any attention to the different operations used because they always produced the same results, but the key insight of Einstein was to posit the Principle of Equivalence that the two operations would always produce the same result because they were equivalent at a deep level, and work out the implications of that assumption, which is the General Theory of Relativity. Thus, a breakthrough in science was achieved by disregarding different operational definitions of scientific measurements and realizing that they both described a single theoretical concept. Einstein's disagreement with the operationalist approach was criticized by Bridgman as follows: "Einstein did not carry over into his general relativity theory the lessons and insights he himself has taught us in his special theory."
http://en.wikipedia.org/wiki/Operationalism
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