Bulletin of the American Physical Society
Joint Fall 2011 Meeting of the APS New England Section and the New England Section of the American Association of Physics Teachers (NES/AAPT)
Volume 56, Number 17
Friday–Saturday, November 18–19, 2011; Amherst, Massachusetts
Session F3: Cosmology, Theory |
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Chair: Lorenzo Sorbo, UMass Amherst Room: Campus Center 165 |
Saturday, November 19, 2011 8:00AM - 8:12AM |
F3.00001: Theoretical Considerations for Black Hole Formation in Supernova Ejecta Andrew Hayes We present a method for detecting regions within a dataset from a simulation of a high energy astrophysical event, such as a supernova, that are unstable to gravitational collapse. This method can be used where the resolution, spatial domain, and/or time span of the simulation may not be sufficient to evolve the region to gravitational collapse natively. The accuracy of the method is demonstrated by applying it to various spherical mass distributions whose stability is known through other means. We have already used the method in the analysis of datasets from three simulations, with negative results. We also discuss the consequences of the ongoing production of low-mass, high-velocity black holes. [Preview Abstract] |
Saturday, November 19, 2011 8:12AM - 8:24AM |
F3.00002: Understanding Cosmological Probes of the Dark Side: Computational Studies of Type Ia Supernovae Robert Fisher, Suoqing Ji, Jan Behrends Each Type Ia supernova (SN Ia) event has very nearly the same intrinsic brightness regardless of where or when in the universe it exploded. Consequently, SNe Ia provide us with standard candles which have enabled precision cosmological measurements leading to the discovery of the acceleration of the expansion of the universe, and of dark energy -- fundamental work recognized by this year's Nobel prize committee. However, despite these advances, the nature of the progenitors which give rise to SNe Ia, and of the explosion mechanism itself, remain mysterious. While evidence strongly suggests that the progenitors consist of at least one near-Chandrasekhar mass white dwarf in a binary system, both the type of companion, and the precise total mass of the system (either near-critical, or sub- or super-Chandra) are being actively investigated. I will discuss recent computational simulations which have begun to unravel the mystery of these remarkable explosions which probe the dark side of the cosmos. [Preview Abstract] |
Saturday, November 19, 2011 8:24AM - 8:36AM |
F3.00003: Relativity on Rotated Graph Paper Roberto Salgado We present visual calculations in special relativity using spacetime diagrams drawn on graph paper that has been rotated by 45 degrees. The rotated lines represent lightlike directions in Minkowski spacetime, and the boxes in the grid (called light-clock diamonds) represent ticks of an inertial observer's lightclock. We show that many quantitative results can be read off a spacetime diagram by counting boxes, using a minimal amount of algebra. [Preview Abstract] |
Saturday, November 19, 2011 8:36AM - 8:48AM |
F3.00004: Blogging as a Research Tool Douglas Sweetser I work on variations of the Maxwell Lagrange density using quaternions and hypercomplex products of covariant 4-derivatives and 4-potentials. The hope is to unify gravity with the symmetries found in the standard model. It is difficult for someone outside academia to get constructive criticism. I have chosen to blog once a week at Science20.com since March, 2011. Over thirty blogs have been generated, most getting more than a thousand views (high mark is 5k for ``Why Quantum Mechanics is Wierd''). The tools used for web and video blogging will be reviewed. A discussion of my efforts to represent electroweak symmetry with quaternions convinced me I was in error. Instead, my hope is to exploit the observation that U(1) is formally a subgroup of SU(2). A battle over gauge symmetry may be reviewed. [Preview Abstract] |
Saturday, November 19, 2011 8:48AM - 9:00AM |
F3.00005: The Universe is not expanding Ari Brynjolfsson Plasma redshift cosmology is a new cosmology that is far superior to the conventional Big-Bang cosmology. It shows that the universe is not expanding, and that there is no accelerated expansion. Closer analyses show that the equations leading to the Big-Bang are wrong or inadequate as they do not take properly into account: the dielectric constant, essential quantum effects, and important effects of the hot plasma, including the plasma frequency in intergalactic space. Plasma redshift cosmology explains the observed solar redshifts, the redshifts of stars, galaxies, quasars and the intergalactic plasma. Comparison with measured solar redshifts shows that Gravitational redshifts of optical lines reverse as the photons move from the Sun to the Earth. This shows that the optical photons are gravitationally repelled and not attracted as surmised in the Big-Bang cosmology. This shows that as star-matter concentrates at the center of galaxies, it turns so hot that the thermal collisions transform old star-matter to photons and primordial matter. This way the universe can renew itself for ever. The primordial matter can diffuse away from the center and is often seen surrounding the galaxy-centers. No Dark Energy, Dark matter, or Black Holes are needed to explain the observations [Preview Abstract] |
Saturday, November 19, 2011 9:00AM - 9:12AM |
F3.00006: Visualizing the Superposition Process Michael Ambroselli, Chandrasekhar Roychoudhuri We demonstrate the dynamic evolution of superposition effects using two intersecting beams of electromagnetic radiation, to underscore the importance of visualizing interaction processes. Recordable fringes within the volume of superposition have time evolving bright fringe patterns, because the two superposed E-vectors oscillate through zero values while staying locked in phase. If a detector registers steady, stable bright fringes, it must do so by time integration. The QM recipe to model energy exchange by taking the square modulus of the sum of the complex amplitudes has this time integration built into it. We also discuss the importance of assigning proper physical processes to the mathematical relationships whenever possible: the algebraic symbols should represent physical parameters of the interactants and the mathematical operators connecting the symbols should represent allowed physical interaction processes and the guiding force. [Preview Abstract] |
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