Welcome to Comps talk season! Our seniors have worked really hard since fall to be able to present to YOU! Because of Covid restrictions, we will broadcast this year’s comps talks on Zoom. All PHAS-related folk, including alumni, faculty emeriti, and family and friends are invited to attend. Abstracts for the first three talks are below.
April Reisenfeld
Wednesday, January 27 2021
4:20 pm on Zoom
Understanding Randomness in Classical and Quantum Physics:
How often do you hear someone say something totally random? When was the last time you met a random person on the street (Ok fine, maybe a long time ago)? “Random” is a word often used colloquially to describe arbitrary, strange, or unexpected events regardless of a speaker’s capacity to know the event’s causal process. Scientifically, randomness is an inextricable unpredictability in a system’s dynamics which exists in both microscopic and macroscopic systems. This randomness manifests itself differently within our physical theories that describe these systems, namely classical and quantum mechanics. Not just a source of discomfort for
those clutching to universal determinism, physical randomness can be practically exploited to generate random numbers. In turn, these numbers provide validity and security to applications such as simulation, statistical sampling, and cryptography. In this talk, I hope to inspire inquiry into the true nature of randomness by upending common misconceptions, examining its prevalence in physics, and demonstrating its utility for generating random numbers. If nothing else, a deeper understanding of randomness in physics will be developed such that everyday use of the word may no longer seem appropriate.
Kyle Fraser-Mines
Friday, January 29 2021
4:20 pm on Zoom
The Carrington Event
From 1 September 1859 to 2 September 1859, Earth experienced the largest geomagnetic storm on record. There were sightings of visible auroras reaching to 18° latitude and the telegraph system was shut down due to changes in the geomagnetic field. Richard Carrington, who the storm is named after, recorded observations of a bright light flash on the sun hours before the onset of magnetic disturbances. The combination of Carrington’s observations, the bright widespread auroras, and the disruption of the telegraphs lead scientists to determine the solar link between these phenomena. Since then scientists have made many discoveries allowing them to understand solar activity, the interaction between the geomagnetic field and the interplanetary magnetic field, and geomagnetic storms. Using modern knowledge on these topics I recreate the events leading up to the Carrington event and explain their effects on Earth. I begin by explaining the coronal mass ejection that caused the storm and how it traveled towards Earth. I then discuss how the magnetic fields interact and cause visible auroras. Finally, I discuss how the interaction with the geomagnetic field made the telegraph system essentially inoperable. In understanding this historic event I set the foundation for understanding how Earth would be affected if a similar geomagnetic storm were to occur today.
Eric Shao
Monday, February 1 2021
8:30 am on Zoom
Physics and Information
The Maxwell demon is solved by the arise of information from the thermodynamic system. In the talk we will investigate the connection between physics and information, but please bear in mind this is still an open question. In the first part, I want to show how thermodynamic entropy is related to and different from the information entropy. There will be a brief dive into the origin and the mathematical form of both entropy and some immediate consequences of them. In the second part, I want to show how we use physics to process information. Starting from physics principles, the Fermi-Dirac Distribution, to electronics, semiconductor, diodes, and transistor (particularly metal–oxide–semiconductor field-effect transistor) and finally reach logic gates, where information can be represented and process in the most basic way.