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Colloquium Schedule

Spring 2022

Galaxies Swept Under the Dust

Jesse Rivera, Visiting Assistant Professor of Astronomy, Swarthmore College
Fri., April 8 at 12:30 pm

Dusty star-forming galaxies (DSFGs) contribute significantly to the cosmic star-formation history of the universe, and are likely progenitors of nearby elliptical galaxies; however, they are challenging to study in detail, in part because their dusty nature makes them difficult to localize at optical wavelengths. Large-area surveys from far-infrared through millimeter wavelengths have proved to be effective at identifying DSFGs that are unusually bright (i.e., gravitationally lensed), and thus easier to study. I will present past and preliminary results on DSFGs selected from a survey of a 470 deg2 equatorial field with the Atacama Cosmology Telescope (ACT), focusing on two systems with spatially resolved mapping of CO(3-2) emission from the Northern Extended Millimeter Array (NOEMA) as well as Hubble Space Telescope (HST) imaging. Lens modelling using a pixel-based algorithm that can be applied to multiple independent velocity channels yields source-plane reconstructions that support the characterization of the morphologies, physical conditions, and kinematics of these extreme star-forming systems. I will also dedicate time to discuss and reflect on my professional trajectory and the many decisions I made throughout my career that led to where I am at presently.

Physics Is More Than Problem-solving: Building Inclusivity and Belonging by Practicing Professionalism

Marty Baylor, Associate Professor and Department of Physics and Astronomy Chair, Carleton College
Thu., March 24, 2022, 4:30 PM

When I’ve asked potential physics majors to reflect on what it takes to be a physicist, their responses essentially write themselves out of the identity that they seem to be striving for. Their narrow definition of what it takes to be a physicist can lead students, particularly students whose identities are under-represented in STEM to feel as if they don’t belong. To help broaden student’s definition of who a physicist is so that they can see themselves in the field now, I have been developing what I am calling the Practicing Professionalism Framework for my courses. This Framework not only helps me help students understand the course content, structures, and skills better, but it also helps motivate in a natural and compelling way that being a physicist is broader than the ability to solve problems and doesn’t require them to win a Nobel Prize. In this talk I will not only present this framework, it’s implementation and its impact on students, I will also describe how I believe it can be expanded beyond physics to other STEM disciplines.

A Random Walk into Optical Signal Processing and Integrated Optofluidic Devices

Marty Baylor, Associate Professor and Department of Physics and Astronomy Chair, Carleton College
Fri., March 25, 2022, 12:45 PM

Light not only has the power to help us learn about the physical world, but it can also help us solve problems that are hard to solve in other ways. I fell into optics through what felt like a winding path to me. As I share about my path from my childhood dreams of being a paleontologist to my current work using photopolymers for integrated optofluidic devices, I will periodically pause to describe the varied optics work I have done along the way at Kenyon College, NASA Goddard Space Flight Center, and CU-Boulder. During this talk, I invite the audience to consider the role of power and privilege in helping me arrive at where I am today.

A Novel Administration of a Sensemaking Instrument in Physics Education

Stephen Hackler, Visiting Assistant Professor, Swarthmore College
Fri., Feb 4, 2022, 12:45 pm

Note: Due to current Covid restrictions, this talk will not be open to visitors. Lunch will be available at 12:20 in the Cunniff Lecture Hall Lobby.

There are numerous survey instruments used to examine student performance over the course of a semester, most of which assess content knowledge. The Math Epistemic Games Survey is a diagnostic instrument for gathering information on student sensemaking in introductory physics course, noted for its length and rigor. Previous research has suggested that student effort (and therefore the fidelity of results) may be improved by shortening the instrument. Through an exploratory factor analysis on MEGS data, we identify 10 key factors and divide each to produce two, half length, mutually exclusive tests. We then administer these half tests to a group of approximately 600 undergraduate introductory physics students at the University of Pennsylvania as pretests and posttests and compare student performance. Our results show that student performance on each test is distributed extremely similarly and that average performance is slightly above that found in previous studies. We therefore conclude that our proposed split administration produces a reliable instrument, which preserves the original validity of the MEGS, and may improve on some of the identified shortcomings of the full MEGS.