Welcome to Physics and Astronomy
Welcome to the website of the Department of Physics and Astronomy at the University of Maine.
Located in the town of Orono, along the banks of the Stillwater River, the University offers a strong traditional education at an affordable price. The state’s land grant and sea grant university and the flagship institution in the University of Maine System, UMaine is one of New England’s premier universities. Our students create success stories — with a wide variety of programs and opportunities — and we do so with world-class faculty members, internationally recognized research; first-rate facilities; a friendly, safe atmosphere; and easy access to some of the best year-round recreation sites in the nation. We are a department comprised of 15 faculty members, all dedicated to teaching and research in areas including, but not limited to, biophysics, nanophysics/surface science, physics and astronomy education research, statistical physics, spiral galaxies and galaxy clusters, and environmental/health physics; 30 Graduate students; and 80 undergraduate majors. We offer BA and BS degrees in physics and engineering physics and also offer minors in both physics and astronomy.
Congratulations to (the soon to be) Dr. Michael Mlodzianoski on the successful defense of your dissertation!!
Candidate for the Doctor of Philosophy (in Physics) degree
Spectral Measurements and Super Resolution Imaging of Single Molecules for
Fluorescence Photoactivation Localization Microscopy
Due to the diffraction limit of light, the resolution of fluorescence light microscopy is limited to ~250 nm. Super resolution techniques such as Fluorescence Photoactivation Localization Microscopy (FPALM) can circumvent this limit and improve the final image resolution by a factor of ten. Photoactivatable fluorescent molecules are stochastically converted from a fluorescent dark state to a bright state and imaged until they photobleach. Only a sparse subset of molecules emits light at any given time, and the cycle of emission and bleaching is repeated through time as data are simultaneously acquired. The resultant single molecules are mathematically localized in order to find their spatial positions to a much higher precision than allowed by the diffraction limit. Super resolved images are generated from the localized molecule positions; typically resulting in a final image resolution on the scale of tens of nanometers.
While localization microscopy can image nanoscale cellular details, the ability to distinguish multiple fluorescent species simultaneously is invaluable in addressing a number of biological questions. Previously published multispecies schemes have divided the detected fluorescence into two distinct spectral channels, often with the ratio between channels used for species identification. However, such ratiometric methods have been limited in the number of species that can be detected simultaneously, and are unable to obtain the emission spectra of the imaged species, thus limiting their ability to distinguish multiple species. We present a localization microscopy method which detects the emission spectrum of each localized single molecule. In this scheme, a prism in the detection path spatially disperses the fluorescence signal according to the emission spectrum of each single molecule, which is recorded in one of two detection channels. The emission spectrum of each single molecule can be used for fluorescent species identification, theoretically allowing a major increase in the number of different species that can be simultaneously imaged in a sample. This technique enables an exciting new family of super-resolution imaging experiments which can report spectral emission changes due to pH, hydrophobicity, redox state, ion concentrations, temperature, or other factors, while also recording precise nanometer molecular locations.
WEDNESDAY, NOVEMBER 4, 2015
ARTHUR ST JOHN HILL AUDITORIUM
Candidate for the Doctor of Philosophy (in Physics) degree
SELF-EFFICACY STATE EXPERIENCES IN INTRODUCTORY PHYSICS: A GENDER STUDY
Nationally, few undergraduates choose physics as a major, and among those who do, very few are women. One potential contributor to this problem is the impact that physics instruction seems to have on students’ self-efficacy, which is student’s thoughts and feelings about their capabilities to succeed as learners in physics. Self-efficacy plays an important role in student achievement in academics generally and in students pursuing STEM degrees. Conversely, research has shown that the self-efficacy of both men and women tends to be reduced after taking traditional and research-based physics courses. Moreover, self-efficacy tends to be reduced further for women than for men. However, it remains unclear whether the negative shifts in self-efficacy in physics are caused by physics instruction. It may be that the negative shift in self-efficacy reflects a broader trend in university education that has little to do with physics per se. I investigated this and other alternative explanations for negative shifts in self-efficacy in physics courses using an in-the-moment measurement technique called the Experience Sampling Method. The technique allowed me to collect students’ day-to-day feelings of self-efficacy, which I called states, and to compare students’ self-efficacy states in physics to those in other STEM courses. I found that students experienced much lower self-efficacy states in physics than in their other STEM courses. Moreover, this difference largely affected women who experienced physics, and only physics, with much lower self-efficacy states than men. Given that experiences are an established sources of self-efficacy beliefs and women also had much more negative shifts in their self-efficacy beliefs I concluded that the experience of physics instruction was probably a causal factor in women’s reduced self-efficacy. Further analysis found that the gender difference in self-efficacy states was more than twice that predicted by students’ pre-course achievement, attitudes and beliefs. Thus I tentatively concluded that the negative impact on women’s self-efficacy resulted from inequities in the physics-learning environment rather than preexisting gender differences. I present evidence that the physics course I investigated was similar to other research-based physics courses and tentatively I concluded that physics instruction in general is detrimental to women’s self-efficacy.
Wednesday, November 11, 2015
Arthur St. John Hill Auditorium
Graduate Student and Acting Director of the Emera Astronomy Center, Scott Mitchell, took this photo recently of the Great Orion Nebula. The picture was taken using four 5-minute exposures through clear, red, blue and green filters on our state-of-the-art, research grade telescope. This image gives us a wonderful view of the nebula, which is over 1,000 light years away from Earth.
Professor and Department Chair, Dr. Michael Wittmann, has been named a Fellow of the American Physical Society for his “foundational research into student learning of physics, pioneering work in K-12 teacher development, and leadership in building community for physics education researchers.” Only about half of one percent of APS members are named as Fellows. Congratulations, Dr. Wittmann!!
Just this week, the Physics Review Special Topics: Physics Education Research published a “focused collection” of papers on physics education research in upper division physics. Of the 19 articles published in the collection, six of them were written by faculty and/or graduates of the Department of Physics and Astronomy. Congratulations on all of your hard work and research! We are all very proud!!
Check out the following links to read the articles published in the collection:
Student Understanding of the Boltzmann Factor – Trevor I. Smith, Donald B. Mountcastle and John R. Thompson
Identifying Student Difficulties With Entropy, Heat Engines and the Carnot Cycle – Trevor I. Smith, Warren M. Christensen, Donald B. Mountcastle and John R. Thompson
Mathematical Actions as Procedural Resources: An Example From the Separation of Variables – Michael C. Wittmann and Katrina E. Black
Brief, Embedded, Spontaneous Metacognitive Talk Indicates Thinking Like a Physicist – Eleanor C. Sayre and Paul W. Irving
Becoming a Physicist: The Roles of Research, Mindsets and Milestones in Upper-division Student Perceptions – Paul W. Irving and Eleanor C. Sayre
Experts’ Understanding of Partial Derivatives Using the Partial Derivative Machine – David Roundy, Eric Weber, Tevian Dray, Rabindra R. Bajracharya, Allison Dorko, Emily M. Smith and Corinne A. Manogue
Congratulations to Jennifer Lilieholm and Julia Sell on their successful undergraduate thesis defenses! Congratulations, also, to Bryn Nugent, who successfully defended her Master’s thesis. Congratulations, ladies!! The Department of Physics and Astronomy is very proud of you and all your hard work!
The following videos were taken with the use of drones by Professor Sam Hess and his students. Enjoy!
Winter scenes of UMaine Campus, featuring Fogler Library, Stevens Hall, the UMaine South Entrance, the Collins Center, Bennett Hall, the Mall and Memorial Union, West Campus and the Stillwater River, East Campus, Hitchner Hall, the Bear Statue, the Engineering Science Research Building, Alfond Arena, the Alumni House, and a campus panorama.
Video of the Emera Astronomy Center at UMaine, while under construction, featuring the new observatory and planetarium.