Bulletin of the American Physical Society
2007 APS March Meeting
Volume 52, Number 1
Monday–Friday, March 5–9, 2007; Denver, Colorado
Session L20: History of Physics; Cosmic Microwave Background |
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Sponsoring Units: FHP Chair: William Evenson, Utah Valley State College Room: Colorado Convention Center 105 |
Tuesday, March 6, 2007 2:30PM - 2:54PM |
L20.00001: The Missing Part in the Story of Spin: What is the Spin Content of Stern-Gerlach? Jean-Francois S. Van Huele Explaining the complex structure of atomic spectra was a determining factor in the development of the old quantum theory and it contributed significantly to the invention of quantum mechanics in the 1920s. Eventually it also led to the introduction of an additional degree of freedom for the electron and to the spin model of Goudsmit and Uhlenbeck. All along, information on the Stern-Gerlach effect, which is widely interpreted today as a manifestation of spin, was available. It did not seem to influence the invention or the acceptance of spin. We examine the connection between spin and Stern-Gerlach and review the lack of mutual influence in the publication record. We conclude by suggesting possible reasons for the absence of the Stern-Gerlach effect in the story of spin. [Preview Abstract] |
Tuesday, March 6, 2007 2:54PM - 3:18PM |
L20.00002: The Entangled Histories of Physics and Computation Cesar Rodriguez The history of physics and computation intertwine in a fascinating manner that is relevant to the field of quantum computation. This talk focuses of the interconnections between both by examining their rhyming philosophies, recurrent characters and common themes. Leibniz not only was one of the lead figures of calculus, but also left his footprint in physics and invented the concept of a universal computational language. This last idea was further developed by Boole, Russell, Hilbert and G\"odel. Physicists such as Boltzmann and Maxwell also established the foundation of the field of information theory later developed by Shannon. The war efforts of von Neumann and Turing can be juxtaposed to the Manhattan Project. Professional and personal connections of these characters to the development of physics will be emphasized. Recently, new cryptographic developments lead to a reexamination of the fundamentals of quantum mechanics, while quantum computation is discovering a new perspective on the nature of information itself. [Preview Abstract] |
Tuesday, March 6, 2007 3:18PM - 3:42PM |
L20.00003: Einstein's Jury: Trial by Telescope Jeffrey Crelinsten While Einstein's theory of relativity ultimately laid the foundation for modern studies of the universe, it took a long time to be accepted. Between 1905 and 1930, relativity was poorly understood and Einstein worked hard to try to make it more accessible to scientists and scientifically literate laypeople. Its acceptance was largely due to the astronomy community, which undertook precise measurements to test Einstein's astronomical predictions. The well-known 1919 British eclipse expeditions that made Einstein famous did not convince most scientists to accept relativity. The 1920s saw numerous attempts to measure light-bending, as well as solar line displacements and even ether-drift. How astronomers approached the ``Einstein problem'' in these early years before and after the First World War, and how the public reacted to what they reported, helped to shape attitudes we hold today about Einstein and his ideas. [Preview Abstract] |
Tuesday, March 6, 2007 3:42PM - 4:06PM |
L20.00004: Forty lost years of Coherent States Kavan Modi In search to satisfy the correspondence principle Schr\"odinger in 1926 introduced the minimum uncertainty state. Almost forty years later in 1963 Glauber put these states to use in what now know as quantum theory of optics. He also gave them the name we know them by, coherent states. And soon after Sudarshan completed Glauber's unfinished work in achieving the theory of quantum optics. Crucial mathematical work was done in these forty years to able Glauber to consider these states. I will discuss why Glauber was attracted to these states. I will talk about what it was that Schr\"odinger was after, and why they were forgotten for almost forty years. [Preview Abstract] |
Tuesday, March 6, 2007 4:06PM - 4:30PM |
L20.00005: Reception of the Kaluza Theory in Britain, 1921-1958 Norman Redington The Kaluza five-dimensional unified thoery was part of a programme to geometrise physics largely abandoned in the wake of the successes of quantum mechanics. However, a small group of British physicists continued to work on the subject throughout the middle decades of the 20th Century. [Preview Abstract] |
Tuesday, March 6, 2007 4:30PM - 4:54PM |
L20.00006: On the origins of the Raman Effect Somaditya Banerjee I explore the events that led to the discovery of the Raman effect by C.V. Raman and K.S. Krishnan at Calcutta in 1928. I also argue that, although the Raman effect was generally seen as providing strong evidence for the quantum nature of light, Raman himself was a staunch supporter of the classical wave theory of light. This work is part of a larger project, which seeks to understand the role of Raman scattering in the experimental verification of the quantum dispersion theory of Hendrik A. Kramers, which formed a bridge between Bohr and Sommerfeld's old quantum theory and Heisenberg's matrix mechanics. [Preview Abstract] |
Tuesday, March 6, 2007 4:54PM - 5:06PM |
L20.00007: COBE and the Absolute Assignment of the CMB to the Earth. Pierre-Marie Robitaille, Dmitri Rabounski The FIRAS instrument on COBE initially reported a CMB temperature of 2.730+/-0.001 K (1$\sigma )$. At the same time, using the 1st derivative, FIRAS reported a CMB temperature of 2.717+/-0.003 K (1$\sigma )$. These two values are significantly different at the 99{\%} confidence interval. In order to remove this significance, NASA lowered the absolute value of the CMB by changing the calibration on the external calibrator long after launch. It also raised the error bars on the second value. However, the observed difference in the CMB temperature measured by these two methods may well constitute evidence that the CMB monopole arises from the Earth. It should be assumed that a second, much weaker, microwave field exists both at L2 (the WMAP position) and at the COBE position. Motion through this much weaker field is responsible for the dipole observed. The value of the CMB temperature obtained by the 1st derivative is sensitive to motion. It is also sensitive to the complicating effect of the weak field also present at L2 when sampling the CMB temperature using FIRAS. The presence of a second weak field at L2 and the Earth is required in order for COBE to be able to resolve this situation. The PLANCK satellite should soon reveal that that CMB monopole does not exist at L2. [Preview Abstract] |
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