October 2006
THE FORCE
DEPARTMENT OF PHYSICS AND ASTRONOMY
FRANKLIN AND MARSHALL COLLEGE
FALL 2006
NEW FACES IN THE PHYSICS AND ASTRONOMY DEPARTMENT
The department welcomes two new faculty this semester. Dr. Fronefield Crawford, III has accepted a tenure track position in Astronomy and Astrophysics. Dr. Paul Schmidt joins the department teaching physics on a one year visiting appointment.
Froney Crawford joined the department this summer coming from Haverford College, where he taught for 4 years in the physics and astronomy department. Most of his teaching there was in the physics curriculum, so he is looking forward to trying out some new courses in astronomy here. Prior to Haverford, Froney worked as a systems engineer in the remote sensing technology group at Lockheed Martin. He got his B.A. in astrophysics from Williams College ands his Ph.D. from MIT.
Froney's research is in the field of radio pulsars, which closely aligns with Andrea Lommen's research. They focus on different aspects of pulsars and use different techniques in their research, so although there is some overlap in their activities, there is enough of a difference to be complementary. They hope that F&M will soon become known as one of the centers of pulsar research in the United States. Froney has used the Parkes telescope and the Australia Telescope Compact Array (both in Australia), and more recently the Arecibo telescope in Puerto Rico (all of these are radio telescopes). This past year he and collaborators had a few papers published in some astronomy journals, and you can read them if you are interested by following links from his web page.
Froney originally hails from suburban Philadelphia and currently lives with his wife Jill and kids Cameron (5) and Sarah (2) in Phoenixville, PA in neighboring Chester County.
Froney is teaching the lectures and one lab for the introductory course on stars and galaxies this fall. In the spring he'll teach the observing course with Beth Praton and one lab for the introductory course on the solar system.
He welcomes any students in the department to stop by the fourth floor of Hackman and say hello.
PAUL SCHMIDT has joined the faculty as a visiting professor. He graduated with his PhD thi s August before coming to F&M. As a condensed matter spectroscopist, his research interests have focused on understanding luminescence and energy transfer in candidate phosphor materials. As a graduate student much of his work was funded as a partnership with a research group at General Electric. Paul enjoys do-it-yourself projects and loves the outdoors, be it camping, softball, caving etc. His time at UGA overlapped with that of Professor Krebs.
PROFESSOR FRITZ IS NEW DEPARTMENT CHAIR
This July Linda Fritz became chair of the department replacing Professor Greg Adkins at the end of his three year tenure as chair. Linda will be chair for the next three years. Her office is Hac200A and her new phone extension is 3908.
PHYSICS AND ASTRONOMY CLUB FALL PICNIC
The Physics and Astronomy Club kicked off the semester with a picnic on September 27 in Buchanan Park. The picnic was well attended by both students and faculty. Club President, Rebecca Sobel said there are currently no concrete plans for the club but she hopes to get organized further into the semester.
PROFESSOR LOMMEN WRITES FROM DOWN UNDER
Professor Andrea Lommen is on a one-year research leave in Australia. She recently sent this letter to the department:
Greetings from Down Under. I’m spending the year on leave at the Australia Telescope National Facility (ATNF) in Sydney, Australia. Steve and I and Rose and Xyla will be here until June of 2007. While I am enjoying myself here I am sorry that I will miss the first year with Astronomy Professor Fronefield “Froney” Crawford as he joins the Physics and Astronomy Department Faculty. With Professor Crawford combining forces (pun intended) with Professor Elizabeth Praton it promises to be a great year for the Astronomy Program.
In May the department bid a fond farewell to Professor Jacquelynne Milingo who is now an assistant professor at Gettysburg College. We will miss her and are looking forward to seeing her at Central Pennsylvania Consortium Annual Astronomer’s meetings for many years to come.
Three Franklin and Marshall Students, Rebecca Sobel, Tim Falkner and Rick Kipphorn, spent the month of June with me at the ATNF researching the prospect of using pulsars to detect gravitational waves. A pulsar is a dead star that acts as a radio beacon. As it spins it emits light like a lighthouse; for every rotation you see a pulse. Any disturbance in space time between us and the pulsar, such as a gravitational wave, would theoretically be detectable by telescopes on earth.
Rebecca Sobel ’08 tackled the problem of how one might detect a brief burst of gravitational waves. She took advantage of the quadrupolar spatial signature of gravitational waves. Remember those sphericalharmonics: the Ylm’s? For gravitational waves the l=2 terms dominate. Rebecca wrote a computer program to fit spherical harmonics to a collection of pulsar data to search for gravitational waves.
Tim Falkner ’07 worked on the problem of the solar wind mucking up the precision with which we can time the pulsars. The solar wind is essentially a bunch of charged particles coming from the sun. This plasma changes the index of refraction and therefore the light-travel time from the sun. As the pulsar signal passes near the sun, it can be slowed down substantially. Tim worked to improve our models of the solar wind, such that it can be better corrected for in pulsar timing.
Rick Kipphorn ’06 investigated the possibility that binary pulsars can be used to detect gravitational waves. In this case we would be looking for anomalous changes in the decay of certain properties of the binary. For example, we expect the eccentricity of the binary to change with time as the system loses energy. But if the eccentricity changes at a different rate than we expect, it is possible to attribute this additional change to the presence of a gravitational wave passing through the system. In addition, Rick wrote an interface for a pulsar catalog that will undoubtedly be used by generations to come. Rick graduated in May, just published a paper (see Recent Publications) and has just begun graduate school in Astrophysics at Cornell University. Best of luck, Rick!
Rebecca Sobel (below) and Tim Falkner (above) take a break from researching pulsars gravitational waves and the solar wind to visit some koalas and penguins in Australia. 
MONITORING ENERGY
This summer, Linda Fritz and rising junior Raunak Argawal worked on a project to investigate the practicalities of using photovoltaics to generate electricity in Lancaster. They have mounted six 10-watt solar panels on the telescope mounts on the observing deck outside of the fourth floor of Hackman and are monitoring the energy produced each day by the panels. The panels are mounted at different angles to allow them to investigate the optimum orientation of the panels.
To monitor the panels Raunak wrote a LabView program to read the voltages produced by the panels and convert them to instantaneous power. By mapping out the current versus voltage curve for each panel, they were able to determine that the panels would produce maximum power at a load of about 30 ohms. Steve Spadafore built an elegant system using a 30-ohm power resistor and a voltage divider for each panel and connect a National Instruments Data Acquisition board (DAQ) which was then connected to a Dell computer.
Their next project is to build a light display and battery charging system to be powered by a solar panel. The panel will power the LED lights and charge the battery during the day, and the battery will power the lights at night. They plan to mount this in the hallway on the second floor of Hackman as a demonstration of solar power.
You can see the solar panel monitor display on the web at http://155.68.50.228/solar_panel_monitor.html
Linda also taught an informal mini-course on semi-conductors for Raunak and other interested students and faculty members.
PHYSICS NETS KEYSTONE INNOVATION GRANT FOR MATERIALS RESEARCH
The Keystone Innovation Grant (KIG) is a newly created grant program overseen by the Pennsylvania Department of Community and Economic Development (PADCED) aimed at encouraging applied research, commercialization of technology and collaboration between academic research labs and local companies.
The grant awarded to the Physics and Astronomy Department was for a proof-of-concept study on the direct laser writing of channel waveguides in alumina films. The idea is quite simple; a low density and hence low index of refraction alumina film is deposited on a glass substrate. A carbon dioxide laser is then focused onto the film and selectively heats sections of the film. As the film is heated it's structure changes, becoming more dense thus increasing the index of refraction. Since light can be totally internally reflected at the interface between a high index material and a low index material, light can be guided through the channel written by the laser. The process allows for very simple prototyping of optical channels that can then be used to study both fundamental properties of confined light and possible configurations for optical circuit components.
The $10,000 KIG was supplemented by funds from the college and the Hackman Summer Scholars program enabling two students to focus on the project for ten weeks. The KIG and laser densification project represents a real tangible step toward the development of applied material science program at F&M.
PROFESSOR LAROCHELLE RETURNS TO TEACHING
Prof. Christie Larochelle returned to teaching this fall after being on Junior Research Leave during the academic year 2005-2006. During leave she remained on campus, working on research in her lab in Hackman. In addition to continuing her work on energy transfer, she devoted a significant amount of time and energy to expanding the capabilities of her lab. Now, in addition to the pulsed UV laser for luminescence lifetime and time-resolved experiments, she has a deuterium lamp for steady-state photoexcitation and emission measurements. This represents a significant enhancement to our capabilities for spectroscopy experiments in the department.
ADVANCED LAB GOES DUAL PLATFORM
The Advanced Lab for Experimental Methods of Physics has now added three Dell Optiplex PCs to its contingent of computers, so students can get experience using LabVIEW on both Macs and PCs. This is increasingly important with National Instruments concentrating their LabVIEW development on PCs, and with the number of PCs now being used in research labs within the department. This brings the number of computers interfaced to equipment in the room to nine, almost enough for one per student for the ten in the course this fall (we are making do with a laptop for preliminary programming).
AWARD WINNERS
05-06
The following awards were given out at the annual ceremony last spring.
The Frank Durrell Enck Memorial Prize in Physics was awarded to Scott Morgan '06.
The Michael Mumma Prize in Physics recipient was Richard Kipphorn '06.
The Joseph Holzinger Award in Astronomy award went to Kate Barnes '06.
In addition to the individual awards, the following students were recognized by being inducted into Sigma Pi Sigma and named as Kershner Scholars.
Sigma Pi Sigma: Elisabeth Bardenett, Christopher Hobson, Shauna Lehman, Jordan McDonnell, Rebecca Sobel
Kershner Scholars: Shawn Coughlin, Shauna Lehman, Chris Hobson, Micah Dombrowski, Jordan McDonnell, Rebecca Sobel
PROF LACEY ON LEAVE; CONTINUES RESEARCH
Assistant Professor, Scott Lacey is on Junior Faculty Leave this fall semester. Lacey has been using his time away from teaching to continue his research on wave chaos in deformed glass microspheres. The current challenge that is being addressed is fabricating deformed microspheres in the 5 – 10 mm diameter range. Microspheres are formed by heating the end of a glass fiber using a CO2 laser. Not surprisingly it becomes quite difficult to see and manipulate glass at this size scale. The motivation for studying very small oval cavities is to see how size affects the dynamics of light trapped inside. The directions that light leaks out from the microsphere provides information about what is happening inside. From computer models and experiments with larger microspheres it is known that light trapped inside a deformed microsphere follows a chaotic trajectory. As the microsphere is made smaller, however, the wave properties of the light begin to dominate and the very idea of a trajectory for light becomes problematic. Studying the dynamics of light in deformed microspheres over a range of sizes can provide insight into how chaos can emerge from a quantum (wave) system.
Professor Lacey is also teaming up with Professor Krebs to produce a deformed microsphere laser. Krebs brings his expertise in sol-gel processing to this joint venture. A laser requires both an optical resonator and a gain medium. To add a gain medium to the microsphere resonator, it is dipped into a sol-gel that has been doped with a rare earth ion. After drying, the coated microsphere is heat-treated using a CO2 laser.
The photo shows a sphere that was dipped in a europium doped silica sol-gel. The red light is the fluorescence from the europium that occurred when the sphere was illuminated with UV light. This microsphere laser will represent an unusual type of laser in that the gain medium is physically outside of the resonator. This can still work, however, because the resonant modes of the microsphere extend slightly beyond the surface of the glass.
PROF PRATON WORKS WITH STUDENTS ON PROJECTS
This past year I worked with three independent study students and a summer Hackman student: Micah Dombrowski '07, Tim Falkner '07, Shauna Lehman '05, and Elisabeth Bardenett '07. Most of the projects involved the ongoing effort to quantify the bull's-eye distortion in redshift maps of large scale structure in the universe. This distortion is interesting both because it enhances structure lying perpendicular to the line of sight, giving an impression that we are ringed by walls of galaxies (as survey maps seem to show), and because the effect is stronger for a closed universe than for an open universe. A statistic to quantify it could thus provide a new way to measure the closure parameter of the universe. The bottom line on this effort: we've yet to find a satisfactory method for quantifying the bull's-eye, but have made progress exploring some new possibilities.
Micah Dombrowski '07 had worked with me in summer 2005 finishing up an investigation begun by past F&M students Jana Bilikova '04 and Frederika Edgington-Giordano '05. In this project, we looked at a technique called 'path length statistics' that had been developed by our collaborators at University of Kansas. Micah showed what preliminary results had indicated: the path length statistics method doesn't work when applied to mock redshift maps that are more realistic than those previously investigated. Micah presented these results at F&M's fall 2005 research fair.
In fall 2005, Micah and I looked around for a different approach. We decided to explore a method of tracing filaments that employs a technique called 'simulated annealing,' in which small segments are randomly placed and oriented until they line up with the data. This method was originally developed for tracing road networks in satellite photos, but has recently been shown to work well for tracing filaments in 2D simulations of large scale structure.
Micah worked on getting the computer code for the filament finder algorithm from our European collaborators to compile: no small task, given that we had to learn the mechanics of the simulated annealing technique, figure out what the uncommented multi-modulular program was doing, debug the code, and set the parameters correctly, all without aid of written instructions.
Elisabeth Bardenett '07 continued Micah's investigation this past summer by adapting the code to trace filaments in our simulated redshift maps. Our preliminary results: we've found that the simulated annealing filament-finding technique can indeed be adapted to pick out the walls produced by the distortion, but that it has a hard time picking out features buried in noise.
Shauna Lehman '06 and I started exploring yet another approach in spring 2006: a technique called 'morphological component analysis' developed for image processing. This process employs wavelet analysis and two newer techniques called ridgelet and curvelet analysis to separate different shapes in an image. For example, it permits one to break an image of dots and lines into two images: an image of the dots and another image of the lines. We thought perhaps this could be useful for enhancing walls and reducing noise in large scale maps. Unfortunately, we were not able to obtain the computer code from the originator of the method and so were not able to test this idea, since the algorithm was too complicated for us to figure out how to implement with the tools we had available. However, we made progress developing an understanding of how wavelet, ridgelet, and curvelet analysis works. Shauna presented her results to the department at the end of the semester.
Finally, Tim Falkner '07 spent a year working on a completely different project, one begun by past F&M students Steve Rudman '05 and Dusty Klutz '06. Tim continued Steve and Dusty's investigation of the best way to measure the widths of spiral galaxy hydrogen 21-cm line profiles so as to recover the galaxy's true rotation speed. Modeling work by our collaborators at University of Massachusetts has indicated that measuring the width of the profile much higher up than is customary will produce more accurate results.
Last year, Steve had measured line widths of galaxies with known distances and found some indication that the proposed method might indeed be an improvement, but also found that many of the existing profiles were quite noisy, making the results ambiguous. This year Tim worked on modifying the model to simulate the effect that noise and coarse velocity resolution has on the profile. We concluded that measuring widths at the proposed higher level could still work with a noisy profile, but only if a new way of defining the peak profile flux could be found. Tim presented his results at the spring 2006 Central Pennsylvania Consortium astronomy meeting at Dickinson College.
APS MARCH MEETING
This year’s annual March Meeting of the American Physical Society was held in Baltimore, MD. Professors Christie Larochelle and Ken Krebs were among the 6,500 physicists in attendance. Prof. Larochelle presented a paper on the results of research conducted during her research leave titled “Tunable Electronic Energy Transfer in Layered Inorganic Solids Co-doped with Tb3+ and Eu3+.” Prof. Krebs joined over 100 other physicists in traveling to Washington, DC to discuss the importance of science funding with Congressional representatives. Prof. Krebs met with staff members for Rep. Joe Pitts, and reports that, although Rep. Pitts’s staff understands the importance of funding basic science, the Congressman is unwilling to support any such action.
CATCne else and beginning in January 06 has been working on three books.
The 10th edition of Horizons: Exploring the Universe will be published in January 07. His , Wadsworth Publishing, hired his daughter Kathryn Seeds Coolidge '01 to act as associate author on a 5th edition of his book, Astronomy: The Solar System and Beyond. That book will be published in September 06.
Wadsworth also signed Dana Backman to be coauthor with Mike on a new textbook, Perspectives on Astronomy, Seeds and Backman, to be published in February 07.
Mike also reports that a telecourse based on his book Horizons has won an Emmy. The 20-episode television course was created by Coast Telecourses and is distributed as part of a non-profit effort to support distance learning in the US and abroad. The previous telecourse, also based on Horizons, was used for 10 years. He is now starting a new project in September which will overlap with production of Horizons and with Perspectives.
PROFESSOR ADKINS ON SABATTICAL
Professor Adkins completed his three-year term as department Chair this summer, and vacated the Chair’s office in favor of incoming Chair Linda Fritz at the end of June. During his term as chair he also served on the Professional Standards Committee and the Provost Search Committee. He is now on a year-long sabbatical leave, and is happily ensconced in his research office working on a number of projects in theoretical physics.
ADKINS AND COLLEAGUES PUBLISH PAPERS
Professor Adkins published two research papers in 05/06. The first, Recoil corrections in the hydrogen isoelectronic sequence, Physical Review A 73, 032505 (March 2006), was authored jointly with Dr. Jonathan Sapirstein of the physics department at the University of Notre Dame. In this work Adkins and Sapirstein calculated the allowed energies of an electron in a hydrogen-like highly-charged ion. (An example of a highly-charged ion is hydrogen-like uranium, which has 92 protons and a single electron.) These ions are like hydrogen in having only one electron bound to a positive nucleus, but are unlike hydrogen in being bound so tightly that the electron motion is extremely relativistic. Consequently, the usual Schroedinger equation for quantum mechanics is inadequate, and the electron must be described by the Dirac equation, which accounts for the relativistic motion. The particular focus of this project was to calculate recoil corrections that come about because the nucleus doesn’t stay precisely still as the electron orbits around, but instead wobbles a bit. Adkins and Sapirstein developed a novel approached for calculating these recoil corrections, and tested it out with some sample calculations. They will do a systematic calculation of recoil corrections for a number of quantum states and various values of the nuclear charge in a future work.
Nathan McGovern ’03 and Adkins published a paper Application of the effective interaction method to the relativistic Coulomb problem in the American Journal of Physics 73, 759-770 (August 2005). This is a report on work Nathan and Dr. Adkins began during the summer of 2001 as part of a Hackman Scholars project. There is a consensus in the physics world that the final “theory of everything” hasn’t yet been discovered, and that current theories, however successful, are but approximate descriptions valid at best at relatively low energies and large distances. An approximate theory that models well the true behavior of particles and fields for a limited range of energies and distances is known as an “effective theory”. A well-known example of an effective theory is the very successful “standard model” of particle physics. McGovern and Adkins worked out in detail the effective theory describing relativistic electron motion in a Coulomb field and calculated the electron energy levels in such a theory. This is a way to find not just the first order but also the second order corrections due to relativity for an electron bound to a proton in a hydrogen atom.
MCDONNELL, ADKINS AND FELL COMPLETE WORK ON PROJECT
Jordan McDonnell ’07, Richard Fell (of Brandeis University), and Dr. Greg Adkins completed work on an evaluation of cosmological perturbations to orbital motion in star systems, galaxies, and clusters of galaxies. Red shift evidence shows that distant galaxies are moving away from us with a speed proportional to their distance (this is known as Hubble’s law). The interpretation of this fact in Einstein’s theory of general relativity is that “space is expanding”—but what does it really mean for space to expand? McDonnell, Fell, and Adkins asked a simple question: what happens to (relatively) small orbits—such as planetary orbits, or that of a star in a galaxy, or that of a galaxy in a cluster of galaxies—when space expands? Do these orbits also expand, at least a little? Certainly Einstein’s version of the equation of motion for one of these orbiting particles contains a contribution arising from the expansion of space, and this has led various researchers to believe that orbits do in fact expand (a little). However, McDonnell, Fell, and Adkins have shown that inhomogeneities in the distribution of mass (such as exist in any of these orbital systems) lead to an additional contribution to the equation of motion that cancels the first. The net result is a non-expanding Newtonian orbit. A manuscript based on their work has been submitted to the journal Classical and Quantum Gravity for publication.
BABY BOOM UPDATE
Our babies are growing like little weeds. Here are some recent pictures
Charlie Lacey
Charley is the son of Scott and Sarah Lacey. Sometimes known as CJ, he's running all over the place now and talking a bit. He loved swimming in lakes and rivers and both the Pacific and Atlantic this summer. He enjoys books and balls and walking home with Dad through the park. He's got a bit of a stubborn streak and likes to do things himself. Here is another picture when he was on an apple picking expedition.
CJ, we love watching you grow!
Rose and Xyla Lommen Carlson in Australia.
Our gorgeous twins, Rose and Xyla, daughters of Andrea Lommen and Steve Carlson, are growing up to be lovely young ladies. They are currently living in Australia with Mom and Dad while Mom is on sabbatical. The picture shown above has the girls wearing their Mommy's dresses from when she was a little girl. They were handcrafted by Andrea's Aunt Sandy and are being passed on to the next generation.
Justin Krebs, shown here with big brother Nicholas is the picture of his Daddy, Ken Krebs. Ken and his wife Beth have their hands full with these wonderful, lively boys!!
Here is a picture of the brothers enjoying a quiet moment.
Read me a story bro…
We also have a granddaughter addition to the department. Elliot Scout Krantz was born December 27, 2005. She is the granddaughter of our department coordinator Lynn Krantz and daughter of Lynn's son Alex and his wife, Tobbie Krantz.
Scout Krantz
Scout joins her siblings Emma and Tatum along with cousins Zander and Mackey to round out Lynn's abundance of grandkids!
It is so much fun watching our perspective students grow!
BON VOYAGE KATIE!!
Linda Fritz and Ned Dixon's daughter Katie Fritzdixon is spending the year studying in Nancy, France. She is studying at the Nancy branch campus of Sciences Po-Institut d'Etudes Politiques (the Institute for Political Studies). Nancy is near the German border, and Katie will be studying in both French and German. She may even take a course in English!!
Linda & Katie at the airport
Katie has a one bedroom apartment on a cobble-stoned street near the center of the old part of the city. This is Katie's first time living in an apartment so she has to figure out how to do things like sign up for electricity and a phone in French. She is the first and only exchange student that this campus of Science Po has had. There have been a few bugs in the system so far, but Katie seems to be settling in well.
RECENT PUBLICATIONS
Here is a list of some recent publications from our faculty and students:
Andrea N Lommen, Richard A. Kipphorn ’06, David J. Nice, Eric M. Splaver, Ingrid H. Stairs, Donald C. Backer. “T
