University of Minnesota
Ph.D. in Physics, 2012
I graduated from the University of Minnesota with a Ph.D. in physics. My thesis was in astrophysics. I also enjoy helping people develop an appreciation of how nature works. So, right after my Ph.D., I worked as a Lecturer in physics at U.Minnesota (briefly) and then at Texas A&M and the University of Arizona before joining the Department of Natural Sciences at Shawnee State University!
Research opportunities for students & high-school teachers
Two fields excite me—astrophysics and education research. I have projects for both science and engineering majors as well as those majoring in the liberal arts. I am also keen on collaborating with high school teachers. Feel free to contact me if these areas interest you. I welcome your ideas in these fields as well!
In education research
I am working on finding ways to help students learn how to solve problems through analysis than mere memorization of patterns or formulae. Some ideas I am pursuing: How can we get high school students to become 'college ready'? And how can we help students in college (and future teachers) acquire problem-solving skills that will help them excel professionally. Additionally, I work in assessment and evaluation of student learning strategies and that of the tools instructors have developed (particularly in physics education research) to assess learning/teaching effectiveness.
I am working on understanding how matter is distributed in galaxies—those "gigantic islands in the universe" holding together billions of stars, with each star containing its own "stellar system" like the solar system—our home. It is estimated that the universe has around 200 Billion galaxies! Understanding the structure, formation and evolution of galaxies is therefore a key aspect in our understanding of the universe at large. However, even after nearly 80 years of discovering galaxies, and high precision data from state-of-the-art telescopes like the Hubble Space Telescope, there is hardly any consensus on what models accurately describe the structure of galaxies.
It is therefore a fascinating field for me to work on and address several unanswered questions! How about you?
My work shows how one can model the distribution of stars in the oldest and most evolved galaxies in our universe-the ellipticals. The modeling process is applicable to all types of ellipticals-massive through dwarfs-over nearly million-trillion kilometers (~100 kilo parsecs) with very low errors (~ 3%) that are consistent with errors in procuring such data. Additionally, the modeling procedure can unravel the properties of "hidden structures" which could be groups of stars subscribing to similar characteristics. The figures below are two examples of modeling both aspects—low errors and hidden features—in a 'massive' and a 'smaller' galaxy. The bottom profiles show the deviation of the model with data. Hence rms of 0.02 implies approximately 2% error. For further details on what the units mean, come see me and I'll explain them to you. You may also read more about it in these publications in the Monthly Notices of the Royal Astronomical Society
- Dhar & Williams, 2012, MNRAS, vol 427, page 204
- Dhar & Williams, 2010, MNRAS, vol 405, page 340