Brian DiGiorgio’s Comps Presentation
Wednesday, March 1st
3:10 pm in Olin 141
The Large-Scale Structure of the Universe
How is the Universe built? Since the first days of astronomy, philosophers and scientists have tried to construct a model of what the Universe looks like at the largest scales, progressing from a geocentric system of concentric spheres to superclusters of galaxies arranged on incomprehensible distance scales. We will talk about various techniques that astronomers have used to map the Universe. We will detail methods used to determine distances to stars and galaxies and the physics behind them, from parallax to supernovas to relativistic redshift. We will investigate the telescopes and spectrometers that modern astronomical surveys use to carry out these techniques and detect distant galaxies. These measurements allow us to see gigantic structures like clusters, voids, and walls, so we will describe how these structures appear and behave as well as how they formed in the early Universe. Finally, we will look at a map of our galactic neighborhood to see all of the structures that the Milky Way galaxy is a part of, including a live-action analysis of galaxy survey data! Come watch this talk to get an impression for just how large the Universe really is.
Adam Rutkowski’s Comps Presentation
Friday, March 3rd
3:30 pm in Olin 141
Physics of Fusion Energy
For decades, nuclear fusion has been looked to as a potentially ideal source of energy that would be safe, clean, and abundant. However, a fusion reactor has also proved to be extremely difficult to implement, requiring a great deal of physics research and presenting significant engineering challenges. In this talk, I will discuss the physics of the fusion reaction and basic plasma physics, with the goal of demonstrating many of the benefits of fusion power, as well as some of the main difficulties in creating a sustained fusion reaction. I will explain the physics behind some of the most common and high performing reactor designs, and how they address the issue of fusion plasma confinement. In this, I will focus on magnetic confinement methods and their implementation in tokamak and stellarator devices. Lastly, I will introduce the present state of fusion research, outlining some of the progress in the field made by the international ITER tokamak collaboration and by the Wendelstein 7-X stellarator.
Sanjay Chepuri’s Comps Presentation
Monday, March 6th
8:30 am in Olin 141
The Cosmic Microwave Background
Almost immediately upon its discovery in 1965, scientists have recognized the potential for the Cosmic Microwave Background (CMB) to teach us about the history of the universe. The CMB follows almost perfectly a blackbody spectrum, but with slight fluctuations. Detecting fluctuations in the CMB is non-trivial however, because we have to subtract the foreground from the galaxy and correct for the Earth’s motion and atmosphere for ground-based observations. Once we have good detection, we can use these fluctuations to learn about the nature of density perturbations in the early universe using the analogy of sound waves. Another important aspect of the CMB is polarization, which was produced by scattering. Polarization tells us about many types of perturbations in the early universe but the most famous and highly sought-after are gravitational waves from inflation, which is where much of the current CMB research is focused.