Robert Henry Dicke (May 6, 1916 – March 4, 1997) was an American experimental physicist, who made important contributions to the fields of astrophysics, atomic physics, cosmology and gravity. May 6 is the 126th day of the year in the Gregorian Calendar (127th in leap years). ... 1916 (MCMXVI) is a leap year starting on Saturday (link will take you to calendar) // Events January-February January 1 -The first successful blood transfusion using blood that had been stored and cooled. ... March 4 is the 63rd day of the year in the Gregorian Calendar (64th in leap years). ... 1997 (MCMXCVII) is a common year starting on Wednesday of the Gregorian calendar. ... A physicist is a scientist trained in physics. ... Spiral Galaxy ESO 269-57 Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature and chemical composition) of astronomical objects such as stars, galaxies, and the interstellar medium, as well as their interactions. ... Atomic physics (or atom physics) is physics of the electron hull of atoms. ... Cosmology, as a branch of astrophysics, is the study of the large-scale structure of the universe and is concerned with fundamental questions about its formation and evolution. ... ...

Dicke completed his bachelor's degree at Princeton University and his doctorate, in 1939, from the University of Rochester in nuclear physics. During the second world war he worked in the radiation laboratory at the Massachusetts Institute of Technology where he worked on the development of radar and designed the Dicke radiometer, a microwave receiver. He used this to set a limit on the temperature of the cosmic microwave background radiation, from the roof of the radiation laboratory, of less than 20 kelvins. Princeton University, located in Princeton, New Jersey, is the fifth-oldest institution of higher education in the United States. ... Located in Rochester, New York, USA and founded in 1850, the University of Rochester is a private, coeducational and nonsectarian research institution. ... Nuclear physics is the branch of physics concerned with the nucleus of the atom. ... Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km into the air. ... The Radiation Laboratory or often RadLab at Massachusetts Institute of Technology was in operation from October 1940 until December 31, 1945. ... The Massachusetts Institute of Technology, or MIT, is a university located in the city of Cambridge, Massachusetts, USA. MIT is one of the worlds leading research institutions in science and technology, as well as in numerous other fields, including management, economics, linguistics, political science, and philosophy. ... This long range radar antenna (approximately 40m (130ft) in diameter) rotates on a track to observe activities near the horizon. ... In cosmology, the cosmic microwave background radiation (most often abbreviated CMB but occasionally CMBR, CBR or MBR) is a form of electromagnetic radiation discovered in 1965. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ...

In 1946, he returned to Princeton University, where he remained for the rest of his career. He did some work in atomic physics, particularly on the laser and measuring the gyromagnetic ratio of the electron. The range of sizes in which lasers exist is immense, extending from microscopic diode lasers (top) to football field sized neodymium glass lasers (bottom) used for inertial confinement fusion. ... Gyromagnetic ratio is the ratio of magnetic dipole moment to the angular momentum of an atomic nuclei. ...

He was instrumental in early measurements of the cosmic microwave background radiation, whose physics he worked out with Philip James Edwin Peebles, David Todd Wilkinson and Peter G. Roll (having forgotten the earlier prediction of George Gamow). The Dicke radiometer has been used for many measurements of the background radiation, including that of Arno Penzias and Robert Woodrow Wilson. Philip James Edwin Peebles (born April 25, 1935) is an Canadian-American astronomer. ... David Todd Wilkinson (13 May 1935 – 5 September 2002) was a world-renowned pioneer in the field of cosmology, specializing in the study of the cosmic microwave background radiation (CMB) left over from the Big Bang. ... George Gamow (pronounced GAM-off) (March 4, 1904 – August 19, 1968) , born Georgiy Antonovich Gamow (Георгий Антонович Гамов) was a Ukrainian born physicist and cosmologist. ... Arno Allan Penzias (born April 26, American physicist. ... Robert Woodrow Wilson (born January 10, 1936) is an American physicist. ...

He spent the remainder of his career developing a program of precision tests of general relativity using the framework of the equivalence principle. With Carl H. Brans, he developed Brans-Dicke theory, an equivalence-principle violating modification of general relativity inspired by Paul Dirac's large numbers hypothesis and Mach's principle. He made measurements of solar oblateness which were useful in understanding the perihelion precession of Mercury's orbit, one of the classical tests of general relativity. General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915. ... In relativity, the equivalence principle is applied to several related concepts dealing with gravitation and the uniformity of physical measurements in different frames of reference. ... Carl H. Brans is a physicist on the faculty of Loyola University. ... In mathematical physics, the Brans-Dicke theory of gravitation (sometimes called the Jordan/Brans/Dicke theory) is a well-known competitor of Einsteins theory of general relativity. ... Paul Adrien Maurice Dirac Paul Adrien Maurice Dirac, OM (IPA: [dɪræk]) (August 8, 1902 – October 20, 1984) was a British theoretical physicist and a founder of the field of quantum physics. ... The Dirac large numbers hypothesis refers to an observation made by Paul Dirac in 1937 relating ratios of size scales in the universe to that of force scales. ... Machs principle is a hypothesis first stated by the physicist and philosopher Ernst Mach in 1893, which states that: The inertia of any system is the result of the interaction of that system and the rest of the universe. ... The Sun (or Sol) is the star at the center of our Solar system. ... Another view of Keplerian orbital elements. ... There are two types of precession, torque-free and torque-induced, the latter being discussed here in more detail. ... Atmospheric characteristics Atmospheric pressure trace Potassium 31. ... In physics, an orbit is the path that an object makes, around another object, whilst under the influence of a source of centripetal force, such as gravity. ...

Together with Philip James Edwin Peebles he was instrumental in transforming cosmology into a respectable field of inquiry in physics. Philip James Edwin Peebles (born April 25, 1935) is an Canadian-American astronomer. ...

External links

• National Academy of Sciences biography
• BAAS 29 (1997) 1469, obituary

References

• J. R. Kuhn, K. G. Libbrecht and R. H. Dicke, "The surface temperature of the sun and changes in the solar constant", Science 242, 908 (1988).
• J. G. Williams, R. H. Dicke, P. L. Bender, C. O. Alley, D. G. Currie, W. E. Carter, D. H. Eckhardt, J. E. Faller, W. M. Kaula, J. D. Mulholland, "New test of the equivalence principle from lunar laser ranging", Phys. Rev. Lett. 36, 551 (1976).
• P. J. E. Peebles and R. H. Dicke, "Origin of the Globular Star Clusters", Astrophys. J. 154, 891 (1968).
• R. H. Dicke and H. M. Goldenberg, "Solar Oblateness and General Relativity", Phys. Rev. Lett. 18, 313 (1967)
• R. H. Dicke, P. J. E. Peebles, P. G. Roll and D. T. Wilkinson, "Cosmic Black-Body Radiation", Astrophys. J. 142, 414 (1965).
• P. G. Roll, R. Krotkov and R. H. Dicke, "The Equivalence Of Inertial And Passive Gravitational Mass", Ann. Phys. 26, 446 (1964).
• R. H. Dicke, "Mach's Principle And Invariance Under Transformation Of Units," Phys. Rev. 125, 2163 (1962).
• C. Brans and R. H. Dicke, "Mach's Principle And A Relativistic Theory Of Gravitation," Phys. Rev. 124, 925 (1961).