Fall 2011 Physics Colloquium

Unless otherwise noted, lunch is served 15 minutes before each colloquium. Colloquium schedules from other semesters can be found at the *Colloquium Archive*.


Thursday, September 15, 12:05 pm - Tome 115
Marc Koehler - "Laser Vibrational Spectroscopy for Food monitoring and the Detection of Different Food Additives"
Abstract: Monitoring and analysis of food additives become an urgent need for ensuring food safety for consumers. The combination of Raman and Infrared spectroscopic signatures were used to characterize different carotenoids for food coloring. Results showed identification and discrimination of tested carotenoid species were possible through Raman and Infrared spectroscopy.


Christine Welling - "Alternative Mounting Systems for the Galileoscope"
Abstract: The Galileoscope is an inexpensive kit telescope used for educational purposes, and has been distributed worldwide. It must be mounted to something, such as a tripod, to achieve optimal use. However, in many countries, tripods are not affordable. During Christine's REU, she developed and tested alternative mounting systems for the Galileoscope. She will present some of these systems during her talk.


Thursday, September 22, 12pm - Rector Science Complex Stafford Lecture Room
RUSH HOUR Talk - Professor Dave Richeson - "Proving the Impossible"


Abstract: "Nothing is impossible!" It is comforting to believe this greeting card sentiment; it is the American Dream. Human flight and the four-minute mile were proclaimed to be impossible, but both came to pass. Yet there are impossible things, and it is possible to prove that they are so. In this talk we will look at some of the most famous impossibility theorems - the so-called "problems of antiquity." The ancient Greek geometers tried and failed to square circles, trisect angles, double cubes, and construct regular polygons using only a compass and straightedge. So did future generations of great mathematicians. It took two thousand years to prove conclusively that all four of these are mathematically impossible. No, not even Chuck Norris can square the circle.


Thursday, September 29, 12:05 pm - Tome 115
Dr. Amber Straughn, NASA's Goddard Space Flight Center - "Eyes on the Universe: The Legacy of the Hubble Space Telescope and Looking to the Future with the James Webb Space Telescope"


Abstract: Over the past 20 years the Hubble Space Telescope has revolutionized our understanding of the Universe.  Most recently, the complete refurbishment of Hubble in 2009 has given new life to the telescope and the new science instruments have already produced groundbreaking science results, revealing some of the most distant galaxy candidates ever discovered.  Despite the remarkable advances in astrophysics that Hubble has provided, the new questions that have arisen demand a new space telescope with new technologies and capabilities. She will present the exciting new technology development and science goals of NASA's James Webb Space Telescope, which is currently being built and tested and will be launched this decade.


Tuesday, October 4, 12pm - Rector Science Complex Stafford Lecture Room
RUSH HOUR Talk - Professor Karen Weinsten
"Monkeys in the Snow and Cold: the Evolution of Body Proportions in Macaques"


Abstract: How do we understand the evolution of modern human body size and proportions and their worldwide geographic dispersal during the Pleistocene epoch?  One way is by examining macaques, a genus of monkeys that has the greatest geographic range of all primates second to humans.  Unlike most primates that live solely within the tropics, macaques inhabit diverse regions, including tropical rainforests, mountainous habitats, and northern climates with marked seasonal fluctuations in temperature and snowfall.  This presentation discusses the evolution of body size and proportions in macaques as responses to this environmental diversity as well as the influences of variations in locomotion, phylogeny, and other ecological factors.


Thursday, October 13, 12:05pm - Tome 115
Dr. Bethany Johns, John Bahcall Public Policy Fellow at the American Astronomical Society
"Austerity In the Age of Innovation"


Abstract: Federal budget cuts, deficit spending, raising the debt ceiling, mandatory spending, fiscal responsibility, balancing the budget - these phrases are guiding much of the debate on Capitol Hill.  How does this rhetoric affect the funding for the sciences?


The Administration believes that funding the sciences and education is the way to, "Out innovation, out educate, and out build," the rest of the world and has proposed a federal budget that supports this initiative.  However, the debate in Congress is about how the federal deficit impacts our global economic competitiveness and how cuts in spending are necessary for a stable government.  This debate has led to a late enactment of the fiscal year 2011 federal budget.  There are points along the timeline when you can make an impact on the policy making process.  The Decadal Surveys produced by the astrophysics, planetary science and heliophysics communities in the United States, impact policy by the community coming to a consensus and prioritzing the science it wants to accomplish within the decade.


Dr. Johns will speak on the current events on the fiscal year 2011 budget, the 2012 federal budget, the current climate for science funding, and the impact you can make on the policy making process for astronomy and astrophysics.


Thursday, October 20, 12pm - Rector Science Complex Stafford Lecture Room
RUSH HOUR Talk - Professor Michael Holden
"Fear & Loathing on the Energy Front: A Savaage Journey to the Heart of America's Quest for Cheap & Plentiful Energy"


Abstract: An outsider looks at the conversion to sustainable energy sources from a relatively objective viewpoint.


Thursday, October 27, 12:05pm - Tome 115
Dr. Trevor Smith, Visiting Physics Professor, Dickinson College
"Developing Instructional Strategies for Advanced Physics Courses"


Abstract: Physics education research (PER) is the study of how people think about, learn, understand, and teach topics in and related to physics.  One goal of PER is to identify student  difficulties with a particular topic and to develop curricular materials to address these difficulties.  Results in PER show that guided-inquiry worksheet activities (a.k.a. tutorials) can be effective supplements to traditional lecture instruction in introductory physics classes.  Recent research suggests that tutorials can also be useful within advanced courses.  He will present some of the major findings from the PER literature as well as his own research into developing tutorials for use within advanced undergraduate thermal physcis courses.


Thursday, November 10, 12:05pm - Tome 115
Dr. Tyson Littenberg, NASA Goddard & University of Maryland, College Park
"Rounding the Home Stretch: The Very Near Future of Gravitational Wave Astronomy"


Abstract: Gravitational waves were first predicted by Einstein in 1916.  Nearly 100 years later, the decades-long quest to measure these ripples in space-time is about to bear fruit.  Detectors on the ground are half-way through significant technology upgrades which will increase their sensitivity by an order of magnitude.  Furthermore, while recent budget upheaval has obscured the details, space-borne gravitational wave detectors are seen as a high priority for NASA and ESA, with both agencies currently undergoing aggressive mission concept studies targeting launch dates in the next decade.  He will review the fundamentals of gravitational wave astronomy from the standpoint of detectors and science capabilities.

Tuesday, November 15, 4:30pm - Tome 115
Sigma Pi Sigma Talk & Induction Ceremony
- Ryan Stearrett '07
"Noise in CoFeB/MgO/CoFeB Tunnel Junctions"
Sigma Pi Sigma Dinner - HUB Siderooms 205-206 (You must sign up for dinner in advance.)


Abstract: Noise and fluctuations are used as a probe of electronic and magnetic properties of magnetic tunnel junctions (MTJs). These devices consist of a thin insulating layer (MgO) sandwiched between two ferromagnetic electrode layers (CoFeB). The tunneling magnetoresistance (TMR) of such a device is due to spin-dependent electron tunneling and it depends on the relative orientation of the magnetizations in the electrodes.  This makes MTJs attractive candidates for magnetic sensor technologies. In the past decade, advances in materials science guided by theoretical work have led to nearly a 10-fold increase in TMR, upwards of 600% at room temperature.  If the resulting large signals can be coupled with low intrinsic noise then MTJs can be a disruptive sensor technology for low-frequency applications. Presently, resistance noise, which can be separated into electronic and magnetic fluctuations, limits the performance of a sensor at low frequencies.  This talk describes how the electronic noise arising from tunnel barrier and the magnetic noise from the reference (or exchanged-biased) layer are greatly reduced when the MTJ is thermally annealed.


Thursday, November 17, 12pm - Rector Science Complex Stafford Lecture Room
RUSH HOUR Talk - Professor Gregory Howard - "Synergy, Schminergy: Why Two Kinds of Scientists and All the Public Health People in the World Can't Understand Complex Chemical Exposures"


Thursday, December 1, 12:05pm - Tome 115
Professor Adria Updike, Visiting Physics & Astronomy Professor, Dickinson College
"Lighting Up the Early Universe: Gamma Ray Bursts as Probes of Cosmic Chemical Evolution"


Abstract: Gamma ray bursts (GRBs) are the largest explosions in the universe.  For a brief period of time, they illuminate an otherwise invisible part of the cosmos and allow us a glimpse at some of the earliest galaxies in the universe.  She has been working with the Max Planck Institute for Extraterrestrial Physics on the use of GRBs as probes of the universe, and with NASA Goddard on computational models of chemical evolution in galaxies as probed by GRBs.  She will discuss the history of the GRB field, how GRBs are detected and studied, and highlight some of the most interesting recent results of her collaborations with respect to cosmic chemical evolution.

Monday, December 5, 4:15pm - Tome 115
Senior Research Talks

Marc Koehler & Greg Lawrence -  "NMR Spectroscopy and the Detection of Impurities in Water"


Christine Welling - "Photometry of Underobserved RR Lyrae Variable Stars"


Tuesday, December 6, 12:05pm - Tome 115
Senior Research Talks

Abra Fein, Charlie Alcorn & Morgan Cheatham - "The Spectrum Analyzer and ESR Spectroscopy"


Michael Ryan - "Misbehaving Photon Measurement"


Thursday, December 8, 12:05pm - Tome 115
Senior Research Talks

Derek Frymark - "V723CAS: Data Reduction of a Cataclysmic Variable"


Stuart Flury - "Active Galaxies: Super Massive Black Holes and the Mess They Make"