Bulletin of the American Physical Society
2006 8th Annual APS Northwest Section Meeting
Friday–Saturday, May 19–20, 2006; Tacoma, Washington
Session F1: Plenary II |
Hide Abstracts |
Chair: Francesca Sammarruca, University of Idaho Room: Music Building Schneebeck Concert Hall |
Saturday, May 20, 2006 8:30AM - 9:06AM |
F1.00001: Gravity in the Century of Light: The Gravitation Theory of Georges-Louis Le Sage Invited Speaker: Each generation of physicists, or natural philosophers, has sought to place universal gravitation in the context of its own worldview. Often this has entailed an effort to reduce gravitation to something more fundamental. But what is deemed fundamental has, of course, changed with time. Each generation attacked the problem of universal gravitation with the tools of its day and brought to bear the concepts of its own standard model. The most successful eighteenth-century attempt to provide a mechanical explanation of gravity was that of Georges-Louis Le Sage (1724-1803) of Geneva. Le Sage postulated a sea of ultramundane corpuscles, streaming in all directions and characterized by minute mass, great velocity, and complete inelasticity. Mostly these corpuscles just pass through gross bodies such as apples or planets, but a few are absorbed, leading to all the phenomena of attraction. In a voluminous correspondence with nearly all the savants of the day, Le Sage constantly reshaped his arguments for his system in order to appeal to metaphysicians, mechanicians and Newtonians of several varieties. Le Sage's theory is an especially interesting one, for several reasons. First, it serves as the prototype of a dynamical explanation of Newtonian gravity. Second, the theory came quite close to accomplishing its aim. Third, the theory had a long life and attracted comment by the leading physical thinkers of several successive generations, including Laplace, Kelvin, Maxwell and Feynman. Le Sage's theory therefore provides an excellent opportunity for the study of the evolution of attitudes toward physical explanation. The effects of national style in science and generational change take on a new clarity. [Preview Abstract] |
Saturday, May 20, 2006 9:06AM - 9:42AM |
F1.00002: Relativistic Binary Pulsar Systems Invited Speaker: Radio pulsars in double-neutron-star systems provide the best tests of strong-field gravitational theories. I will present recent observations of PSR B1534+12 and the double-pulsar system J0737-3039A/B. In both cases, the pulsar timing observations are sensitive to multiple relativistic corrections to the basic Keplerian orbit, and therefore yield multiple tests of general relativity, with the double pulsar providing the strongest test to date. General relativistic effects are also observable via profile shape changes due to geodetic precession; for B1534+12 a measurement of the precession rate is possible. I will discuss the implications and future prospects for both systems. [Preview Abstract] |
Saturday, May 20, 2006 9:42AM - 10:18AM |
F1.00003: The Nature of Naturalness Invited Speaker: I will discuss the concept of naturalness in particle physics and how this is guiding the search for new physics beyond the Standard Model. [Preview Abstract] |
Saturday, May 20, 2006 10:18AM - 10:43AM |
F1.00004: BREAK
|
Saturday, May 20, 2006 10:43AM - 11:19AM |
F1.00005: Appreciating the Role of the Engineer in Building Science Research Invited Speaker: The engineering team will typically be brought into a science project, shortly before or just as the project is authorized by its funding agency. The project has thus been defined by studies and reports sufficiently to support a ``Baseline Estimate'' of the costs that will hopefully provide adequate funds for the completed science facilities. The engineering team can bring much to benefit the program. More than simply producing the required bidding documents and providing the non-scientific components of the new laboratory or observatory, the Engineer should be invited to become a part of the project team where he/she can bring the experience of the engineering team to the discussions. Matters such as how to plan, procure, sequence and construct, as well as how to control and report project costs and schedule performance would be useful topics. The common goal then becomes to provide a functioning facility within the budgeted funds to do the intended science. Along the way, lots of interesting issues, questions and challenges may emerge. These may or may not affect the outcome of the project, depending upon how they are handled. Some examples of personal experience of actual events that occurred on projects you may be familiar with, will be described and discussed. [Preview Abstract] |
Saturday, May 20, 2006 11:19AM - 11:55AM |
F1.00006: Project ALPHA: Trapping Antihydrogen Atoms for Fundamental Symmetry Tests Invited Speaker: ALPHA (Antihydrogen Laser PHysics Apparatus) is an international project just getting underway at CERN (Geneva), whose aim is to achieve the first stable trapping of antihydrogen, the simplest atomic form of neutral antimatter. Trapped antihydrogen would offer a unique opportunity to study anti-atoms, and via comparisons with well-studied hydrogen, possibilities to make precision tests of fundamental symmetries between matter and antimatter. In 2002, the ATHENA experiment, and subsequently the ATRAP experiment, succeeded in producing large quantities of cold antihydrogen. However, the anti-atoms produced in these experiments, while nearly at rest, were not confined and soon annihilated on the wall of the apparatus. In order to probe matter-antimatter symmetry at the highest possible precision, it is essential that the antihydrogen be suspended in vacuum to allow for detailed interrogation, e.g. via laser light or microwaves. In this talk, I will first give an overview of antihydrogen physics with the emphasis on results from the ATHENA experiment. I will then discuss the exciting prospects of antihydrogen trapping with the project ALPHA, which is coming on-line this summer. [Preview Abstract] |
Saturday, May 20, 2006 11:55AM - 12:31PM |
F1.00007: Transverse Coherence at Short Wavelength Invited Speaker: Spatially filtered particle and photon sources with nanometer wavelength will enable applications in microscopy and coherent scattering with high spatial resolution and unusual contrast mechanisms. The necessary phase space acceptance in such experiments, which is set by the uncertainty principle, places high demands on source brightness, as measured by particle flux per unit area and solid angle. Much progress along these lines has been accomplished in electron microscopy, where field emission cathodes provide high enough brightness that coherence is now used in many imaging applications. I will present results that illustrate potential applications of two developing sources, one based on soft x-ray undulators at third generation synchrotron radiation facilities and the other based on free jet expansions of helium atoms and hydrogen molecules from a microcapillary nozzle. The coherent flux from these sources provides a useful probe of spatial and temporal correlations on the nanometer length scale and thus will address important issues in how complexity emerges in a variety of soft and hard materials. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700