Ivan Gunther Wednesday, February 24 2021 4:20 pm on Zoom
Photonic Lorentz Violation Theory
It seems as if the laws of physics are invariant under Lorentz transformations, but experimental data on this principle leaves open the possibility of minute violations. Motivated by spontaneous Lorentz violations as indications of new fundamental Planck-scale physics, this paper outlines the theoretical investigations of Lorentz violations by the Standard Model Extension (SME) and other frameworks, focusing on the photon sector. We show the reasoning and constraints that produce the most striking feature of the SME, vacuum birefringence. We use this phenomenon to generate a series of observables in different physical environments, by which experiments do and shall constrain the magnitudes of Lorentz violating perturbations. Current experimental data shows a minuscule and shrinking window for spontaneous photonic Lorentz violations, and further tests will continue to probe for birefringence. Eventually, either a conclusive positive result will emerge, or more promising hints of quantum gravity will render Lorentz violations theoretically irrelevant, leaving us with a universe that is, for all intents and purposes, Lorentz invariant.
Fred Cunningham Friday, February 26 2021 4:20 pm on Zoom
The Raptor Engine
The Raptor engine is a converging-diverging chemical combustion liquid oxygen and methane full-flow staged combustion rocket engine. If you understand what each of these words means individually, but would like to understand what they mean when put in that particular sequence, then this paper is definitely for you. To bring meaning to these words, a few mathematical models from dynamics and thermodynamics are used to motivate key rocket engine parameters. Also, some of the engineering needed to manipulate these parameters is introduced. When possible, the notation is kept to an undergraduate physics level or explicitly defined to demystify some engineering concepts that are otherwise expressed with arcane jargon. Finally, this discussion will provide insight into the challenges of space travel in general.
Lucas Mueller Monday, March 1 2021 8:30 am on Zoom
The Strong Nuclear Force