Bulletin of the American Physical Society
Fall 2019 Meeting of the Ohio-Region Section and the Michigan Section of the American Association of Physics Teachers
Volume 64, Number 15
Friday–Saturday, October 11–12, 2019; Flint, Michigan
Session B04: Astrophysics and Theoretical Physics |
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Chair: Timothy Stiles, Kettering University Room: Kettering University Academic Building 4305 |
Saturday, October 12, 2019 8:00AM - 8:12AM |
B04.00001: The Dynamics of Stars in Dwarf Spheroidal Galaxies around the Milky Way in the MOND Regime Raed Diab, Stephen Alexander We present in this study a new method of calculating dispersion profiles and bulk dispersions of three Milky Way dwarf spheroidal satellite galaxies that includes the MOND external field effect. We model the internal gravity of the dwarf galaxies as a Plummer potential and the external gravity of the host is assumed to be uniform. We calculate explicitly the orbital trajectories of ten thousand stars in these potentials. The bulk dispersion and dispersion profile are then calculated statistically. For each galaxy, we obtain results for Newtonian, isolated MOND, and external field effect MOND. By changing the mass-to-light ratio of the spheroidal galaxies we obtained results for bulk dispersions and dispersion profiles that fairly agree with observational data. [Preview Abstract] |
Saturday, October 12, 2019 8:12AM - 8:24AM |
B04.00002: Simulating Realistic Cepheid Light Curves alongside ROTSE-III Data Adam Biery Cepheid variable stars are one of the main methods of determining universal distances and composition in astrophysics. Radially pulsating, strong correlations can be made between the period of pulsation and luminosity of the variable. Therefore, the determination of periods is integral to cepheid research and is an area of which needs significant improvement. The data collected by the Robotic Optical Transient Source Experiment (ROTSE III), lacks a solid method of finding these periods. This is where a simulation has become an increasingly feasible idea that would assist in this effort. The objective of this project is to develop and modify a simulator which is able to replicate light curves and output realistic periods that correlate to a multi-variable set of random input data. This output will be able to correlate several sets of real data. A simulator that can replicate realistic cepheid light curves will allow the testing of period fitting methods to be further refined. This includes the development of physics and CCD simulations, as well as a method to understand errors from real data, and account for them in simulations. This simulator will be a modular and versatile way to accurately depict a cepheid, and assist in calibrating real data. [Preview Abstract] |
Saturday, October 12, 2019 8:24AM - 8:36AM |
B04.00003: Construction of operation of digital intensity interferometer in lab Sahar Nikkhah, Michael Lisa In the 1950's Robert Hanbury Brown invented the groundbreaking technique of ``intensity interferometry,'' solving several problems of Michelson (amplitude) interferometry used in astronomy. In principle, HBT offers the possibility of arbitrarily large baselines (hence arbitrarily small source resolution). However, the technology available in 1950-70 was insufficient to take advantage of this possibility, as signals from two detectors had to be combined in real time. Modern digital technology allows the capture and local storage of photon times and offline correlation, restoring the promise of very large baselines. We have studied the feasibility of such a measurement, simulating a distant star with incoherent light from a \textasciitilde 70 micron region. This source is observed by our multi-detector interferometer, four photomultiplier tubes (PMTs) several meters away. We see the expected HBT correlation in photon times between different PMTs and within each PMT. The dependence of this correlation depends on PMT separation according to expectations based on the source geometry. We will discuss the motivation for our work, the physics of HBT correlations, our experimental apparatus, and the relevance of our results for future developments in HBT astronomy. [Preview Abstract] |
Saturday, October 12, 2019 8:36AM - 8:48AM |
B04.00004: Effect of Nonlocality in Nuclear Potentials on Nuclear Observables and Scattering Wave Functions Graham Tupper, Lei Jin, Charlotte Elster The influence of nonlocality on nuclear scattering observables is still a topic of interest. In this project we start from a local potential and introduce nonlocalities by applying unitary transformations to the Hamiltonian which modify the short-range part of the potential. By modifying the parameters of the transformation we can investigate how the off-shell behavior of the two-body t-matrix as well as the resulting scattering wave function change. We can also investigate spurious effects that may be introduced to scattering calculations when nonlocalities are introduced that do not arise from unitary transformations. [Preview Abstract] |
Saturday, October 12, 2019 8:48AM - 9:00AM |
B04.00005: Einstein made a fifth grade arithmetic error that invalidates relativity theories David E. Pressler Scientists determined the speed of light must be a constant: however, when speed equals a constant; if you change the denominator you must change the numerator; this is called a direct proportion. The ratio of time to distance must always stay the same. Einstein did not change the distance he only changed the time in his 1905 paper; enigmas and paradoxes occur as a result. Additionally, his theories are based only on appearance – what an observer sees. Time absolutely slows down the faster you travel through space. Overwhelming empirical evidence supports this theory by the fact that particles become smaller, more massive, and exhibit time dilation, the faster they travel. Light, which is a transverse wave, requires a solid medium to exist and travel. The Michelson-Morley interferometer experiment proves beyond doubt that space is a solid because in Pressler’s new paradigm shift - both mirrors move towards the center of the device and not just along the direction of motion as previously thought. The speed of light in all reference frames is measured the same by all observers in his own frame in all three directions but the speed of light is different in all other frames at different energy levels. When a gravity field becomes stronger space is less dense, time also slows down, the stronger the gravitational field. [Preview Abstract] |
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