Department News, Spring 2017

Message from the Chair
Department Spotlights
Department Announcements
Alumni Updates/Class Notes
Donor Recognition

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Message from the Chair

 

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Department Spotlights

Corcoran Hall Renovation — A Status Update

GW Astrophysicists Help Build New Instrument for Gemini Telescope

 CUWiP

 

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Department Announcements 

Current Students

Department of Physics Celebrates Graduating Class of 2016!

 

The Society of Physics Students: Year in Review

by Kara Zielinski, President of the Society of Physics Students

Seeing the Wind

For 50 years, astronomers have watched pulsars—neutron stars born in supernova explosions—sweep through space and produce pulses of radiation in different frequency bands. The pulses can be explained by a lighthouse model if the radiation is beamed as it leaves the pulsar magnetosphere. The source of such radiation will appear to pulsate if the beam repeatedly sweeps across the earth as the pulsar spins. However, explaining why pulses are sometimes seen only in the radio and sometimes only in gamma-rays is more challenging. Two studies recently published in The Astrophysical Journal (one of which was authored by physics graduate student Noel Klingler, advised by Professor Oleg Kargaltsev), provide a fresh look at the pulsar phenomenon by examining the structures of the particle wind nebulae produced by two pulsars.

In particular, the Chandra X-ray Observatory images help to answer the question of "why do some neutron stars pulsate only in radio waves, while others only in gamma-rays, and still others in both bands?" by revealing the orientation of these pulsars' spin axes with respect to earth's line of sight and providing an opportunity to check the predictions of sophisticated pulsar lightcurve models. Both papers featured international teams of astronomers and used observations from NASA’s Chandra X-ray Observatory. The results of this research were featured in a press release, NASA webpages, and the main CCAS webpage. Read his papers on PSR B0355+54 (https://arxiv.org/abs/1610.06167) and Geminga Pulsar (https://arxiv.org/abs/1611.03496).

Undergraduate Summer Research

Department News

Michael W. Thacher

The GW APSIS team is delighted to announce the establishment of the Michael W. Thacher Visiting Professor Grant, extending over a three-year span (2017-2020). The grant is providing travel expenses annually for two guests of the Astrophysics Group in APSIS, to visit for a week to work with the group, either on ongoing collaborations or on new projects. Visiting scientists will be selected from a suggested pool by the group members; we are also open to external suggestions for visitors, provided that funds are still available. For further information, please email [email protected].

Michael W. Thacher graduated from GW in 1970 with a Bachelor of Arts degree in philosophy. He began his career as a magazine writer and editor. After receiving an MBA from UCLA in 1983, he assumed increasingly responsible positions in corporate public affairs for ARCO, Northrop, and finally Unocal Corporation. Thacher's fascination with astronomy was sparked at the age of six by his mother, who woke him 5 a.m. one morning to see a spectacularly brilliant Venus shining in the night sky. Early in his career, he wrote articles about space exploration for publications like the Los Angeles Times, Newsday, and Astronomy magazine. For the past 11 years, he has been a tour guide at historic Mt. Wilson Observatory in Southern California. 

"GW has a strong—though not widely appreciated—tradition in physics, with giants like George Gamow and Edward Teller once on the faculty," Thacher said. "It's exciting to help support today's expanding emphasis on astrophysics and big data science." Thacher is married to Rhonda L. Rundle, a former news editor and reporter for The Wall Street Journal. They have two adult sons.

MUSE

In 2010, scientists in Switzerland from the CREMA collaboration made a new and very careful measurement of the size of the proton. This new measurement was amazingly precise, but was 4 percent smaller than the accepted value, disagreeing irreconcilably. This sparked a flurry of other measurements and analyses. The controversy, known as the “Proton Radius Puzzle” caused lots of excitement, with articles in Science and Nature, and in popular science magazines such as New Scientist (and, most recently Science News), and even in The Huffington Post and other news outlets.

There are two ways of measuring the size of the proton. Firstly, one can scatter particles from it, and by observing how the particles scatter, at what frequency and at what angles, one can infer the size of the object from which they scatter. The other mechanism is to look at the “transition lines” in atomic hydrogen: the energy emitted or absorbed when the single electron in atomic hydrogen jumps from one energy level to another. These energy transitions occur at very specific energies, and the energies at which they occur are modified by the finite size of the proton. By measuring these transitions very precisely, one can extract the size of the proton. Until 2010, measurements of the proton size made in both of these ways agreed.

The CREMA collaboration measured the size of the proton very precisely by using a special kind of hydrogen. Regular hydrogen has one proton and one electron. The CREMA collaboration replaced the electron in hydrogen with a muon, a particle just like the electron but about 200 times more massive. The muonic hydrogen is much more compact than regular hydrogen, and this makes the transition energies more sensitive to the size of the proton. Thereby they could make a much more precise extraction of the radius. This “muonic” radius was in complete disagreement with all of the “electronic” (scattering and transition energy) measurements, and scientists need to understand why, but still do not. Some of the potential explanations of the Proton Radius Puzzle are really exciting, including what is referred to as “Beyond Standard Model” physics, which could revolutionize our understanding of nuclear and particle physics. To figure out what exactly is going on, we need more experiments!

GW, in particular Professors Downie and Briscoe, was awarded $900,000 to help build the Muon proton Scattering Experiment (MUSE). MUSE will provide the missing piece of the experimental puzzle: so far there have been electron and muon transition energy measurements, and electron scattering measurements, but no muon scattering measurements with a precision sufficient to address the Proton Radius Puzzle. MUSE will do this and provide a simultaneous measurement of electron and muon scattering with the same apparatus, so will provide a very precise and well-controlled experiment.

GW is responsible for building the electronics which read out the detectors, working on the assembly of the whole experiment, and Professor Afanasev will provide the theory calculations needed to extract the proton size from the experimental measurement. GW Physics professors are playing key roles in this exciting experiment that could hopefully find the answer to this very intriguing puzzle!

GW Team Seeks New Solution Food Safety Challenge

George Washington University researchers have proposed a novel platform using nano-materials to promote safe hygiene practices in food processing and packaging. This new platform will use visible light to kill bacteria and other pathogens.

It has been estimated that pathogens cause 9,400,000 people to get food-borne diseases every year. Most of these pathogens are easier to kill when they are “alone." However, when the population gets higher, they aggregate and form a structure called “biofilm.” and destroying these biofilms becomes very hard. To address this challenge, Ganhui Lan, a GW Department of Physics professor and the co-PI of the proposal, teamed with three other professors from Environmental Engineering, Mechanical Engineering and Chemistry to propose a preventive approach for controlling and eventually eliminating the formation of biofilms.

The team will apply computer-aided methods to optimize the design of nano-material that can efficiently make pathogen-killing residues using visible light. The optimized nano-material will then be fabricated and coated onto the food processing and packaging surfaces to control the multiplying of the pathogen population. And the effectiveness of this new platform will be quantified, evaluated and predicted using computational models for biofilm formation. This interdisciplinary approach has been supported by the United States Department of Agriculture, and a $450,200 grant has recently been awarded to the team for carrying out the research in the next 3 years.

Nuclear Phenomenology Research

GW Postdoc Association

As the body of research at GW grew at a rapid pace, I noticed that such rapid growth brought along a larger number of postdoctoral and research scientists. I, a previous postdoctoral scientist, and a current research scientist at the GW physics department, joined GW in June 2015, and after engaging with the postdocs in my department, I noticed a common theme of desire that we all shared.

We all wished for a community feel for the postdocs at GW: a community that revolves around our wellbeing, that ensures an enjoyable postdoctoral experience for all, and most importantly, that introduce us to and readies us for the ever growing postdoc career opportunities, both in academia and outside.

With these goals in mind, I set off on a path of building such community here at GW, the GW Postdoc Association (GWPA). The idea was first pitched to physics faculty, and was met with encouraging enthusiasm. The idea was met with encouraging enthusiasm from all of my postdoc colleagues, faculty (including physics faculty who were among the first to encourage this effort), departmental chairs, school deans and the administration.

GWPA was launched in September 2016 (https://postdocs.gwu.edu). Its mission is threefold: (1) postdoc career development, (2) easier integration for new postdocs within the community and the university and (3) creating a direct link between postdocs and administration.

So far, we have done three professional development events, and a fourth to come in April. We have also managed a seat on the GW faculty senate, and finally, we have organized some social events for networking purposes. We have plenty of things to look forward to in the future, such as joining the National Postdoc Association (NPA) as a member university, continuing with the professional development events, and building a stronger postdoc family at GW.

Department Events

Nobel Laureate Dr. John Mather Visits GW

In October 2016, the Physics Department Colloquium Series featured guest speaker Dr. John Mather, 2006 Nobel Prize in Physics Laureate, senior astrophysicist at NASA Goddard Space Flight Center (GSFC) and project scientist for the James Webb Space Telescope (JWST).

Dr. Mather was awarded the Nobel Prize in Physics for his work on the Cosmic Background Explorer Satellite (COBE) for which he was principal investigator. His work helped cement the big-bang theory of the universe in showing the thermal spectral nature of the isotropic Cosmic Microwave Background (CMB) as well as the wrinkles in the space-time fabric confirming Professor Stephen Hawking’s theoretical predictions, among others.

The CMB constitutes the first observable light, which was emitted when the universe was only ~300,000 years old compared to its current age of ~14 billions years. This result was "regarded as the starting point for cosmology as a precision science" by the Nobel Prize Committee.

Dr. Mather was listed among Time magazine's “100 Most Influential People in The World” in 2007 and again among Time’s “25 Most Influential People in Space” in 2012 in the same issue as George Washington University's Professor Chryssa Kouveliotou. The colloquium followed meetings organized between Dr. Mather and faculty members of the Physics Department and a pizza lunch organized to facilitate student interactions the speaker.

During 45 minutes, Dr. Mather described to a full auditorium the JWST mission as well as the amazing science challenges that this incredible billion dollars machine currently assembled and tested at GSFC (Greenbelt, Md.) will meet with its 6.5 m diameter mirror located near the Earth-Sun L2 Lagrange point up to one million miles away from us during its five- to 10-years of operation starting in 2018. Dr. Mather told us how the infrared light collected by JWST will help us to understand the distant and, therefore, early universe, to probe the space-time fabric, to search for Earth-size new planets orbiting around far, far away stars and to explore their ability to host life. Dr. Mather's visit ended with a dinner counting students, postdocs and faculty members of the physics department.

4th DC/VA/MD Summer Astrophysics Meeting

The GW Physics Department and the Astronomy, Physics, and Statistics Institute of Sciences (APSIS) organized and hosted the 4th annual DC/VA/MD Summer Astrophysics Meeting (on July 15, 2016) focused on astronomy and astrophysics research by junior scientists (senior undergraduates, graduate students and junior postdocs). The aim of this meeting was to bring local students and researchers (e.g., faculty, post-docs, NASA researchers) together to interact, network, and learn about other's research. About 40 participants attended the meeting. The meeting was held at GW for the second time. The first time the meeting took place at GW in the summer of 2014. Physics graduate students Jeremy Hare and Noel Klingler played key roles in organizing the meeting.

Astronomy Night 2016 at the National Mall

The annual Astronomy Night event takes place at the National Mall and will occur on June 2nd in 2017 (from 6-11 p.m.). More information about the event and its precise location on the National Mall can be found at the event's website.

This free public event, organized by Dr. Donald Lubowich from Hofstra University, regularly draws thousands of people who are interested in astronomy. GW astronomers have been taking part in the event for the past three years. The GW table at the Astronomy Night 2016 featured hands-on activities and demonstrations, solar viewing, and videos about the research taking place at GW with the participation of faculty (Oleg Kargaltsev and Alexander van der Horst), postdocs (Blagoy Rangelov) and students (Jeremy Hare, Nick Gorgone and Noel Klingler). The event also featured optical, and/or radio telescope observations of the sun, moon, Mars, Jupiter and Saturn; a planetarium show with a portable blow-up dome; and a chance to mingle with astronomers from various places (such as NASA and Space Telescope Institute).

 

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Alumni Updates/Class Notes

Frederick Battista, BA ’10 asks, “Did you know that software engineering is less fun than studying the fundamental nature of the universe? You did? How sad! And yet, it is fun to build things...”

Nayha Dixit, BS ’04, is a board certified medical physicist in radiation oncology at UCSF in San Francisco.

Derek Jones, BA, BS ’11, has been actively designing across the country in theatre, dance, opera, events, museums, architecture, art installations and more. He is the lighting design professor at Long Beach City College.Derek resides in Los Angeles.

Gregg Khodorov, BS ’15, is two years into a five-year MD/MBA joint degree program at Rutgers Robert Wood Johnson Medical School. He is passionate about fostering innovation in healthcare, and is co-president of the Biomedical Entrepreneurship Network (see benrwj.com).

Jennifer Kuczynski, BS ’11, MS’16, completed her MS in systems engineering at GW in 2016. She is currently working at MITRE and living in Northern Virginia.

Matt Palmer, PhD ’01, works as a quantitative financial analyst for Bank of America in Atlanta. This past summer, he joined the board of directors of the Atlanta Shakespeare Company (aka The Shakespeare Tavern).

Rohit Patil, BS ’13, will be graduating from GW Medical School this May. He will then go to the University of Maryland for a residency in urology!

Krishna Tewari, BS ’80, received an MS and PhD in physics at American University in Washington, D.C. Krishna worked at NASA Goddard on various projects including COBE for 33 years and retired in 2013.

 

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Donor Recognition

The Physics Department would like to gratefully acknowledge the following generous donors who made a gift to the school from January 1, 2016 to December 31, 2016.

+ Faculty/Staff | # Parent | ~ Student | * Friend

Pie Frey, *

Mark V. Hughes III, BA ’69, MS ’77

Peter F. Koehler, MS ’63

Carla H. Messina, MS ’62

W. Stuart Riggsby, BA ’58

Rise G. Schnizlein, BS ’71

Ilana L. Spar, BA/BS ’08

Michael W. Thacher, BA ’70