Colloquium Series

September 5th

September 12th

Student Poster Session

September 19th

Werner Heisenberg, J. Robert Oppenheimer, and the Bomb

Mark Walker, Union College

The recent movie by Christopher Nolan examined J. Robert Oppenheimer and the building of the first atomic bomb. Oppenheimer’s counterpart in Germany during the war was arguably Werner Heisenberg. This talk will compare and contrast the two physicists and their work on nuclear weapons.

September 26th

Understanding Nuclear Physics Through Hadron Spectroscopy

Gabriel Rodriguez, Florida State University (Virtual Colloquium)

Hadron spectroscopy offers a powerful window into the fundamental forces that govern matter at the smallest scales. In this talk, we will explore how physicists study hadrons—particles made of quarks and bound together by gluons—to better understand the strong nuclear force. Experiments are conducted throughout the world to push our understanding of hadrons further; I will focus on the GlueX experiment at Jefferson Lab, which aims to map the spectrum of exotic hadrons. Designed for an undergraduate audience, this talk will provide an accessible introduction to the key concepts and methods of hadron spectroscopy, offering insights into both the physics and research conducted within the GlueX collaboration.

October 3rd

Joint Seminar With Chemistry

October 10th

Title: Exploring Hadrons with the GlueX Experiment

Amy Schertz, Indiana University

At the deepest level, matter is composed of elementary particles called quarks and gluons, which are bound into hadrons by the strong nuclear force. Examples of hadrons include the protons and neutrons in the nuclei of everyday atoms, as well as unstable baryons and mesons which are only found in extreme environments such as high-energy reactions. Through analysis and classification of which hadrons can be produced in experiments, we are able to learn how the strong nuclear force binds quarks and gluons into hadrons.

The Gluonic Excitations Experiment (GlueX), located at Jefferson Lab in Newport News, VA, has the goal of mapping out the light quark meson spectrum and searching for exotic meson configurations. The status of exotic meson searches at GlueX will be presented, with updates on its first exotic publication.

October 17th

October 24th

Astrophysical Alchemy: The mysterious origins of the heaviest elements

Rebecca Surman, University of Notre Dame

While the processes that form the light (hydrogen, helium) and intermediate mass (carbon through iron) elements found in our bodies and in our solar system are well understood, we still don't know where roughly half of the elements heavier than iron were made. From the solar system abundance pattern of these nuclei, we can tell they were synthesized in a very hot environment with lots of free neutrons. These conditions are quite strange, however, and where they could be found in the galaxy is still uncertain. Some candidate sites are within the galaxy's most violent events: the deaths of massive stars in supernova explosions, and the collisions of two neutron stars or a neutron star and a black hole. Here we will review the basics of the origins of the chemical elements, and discuss how new evidence from a variety of sources—from gravitational waves to experiments with extreme nuclei—can be used to solve this longstanding mystery.

October 31st

Bio-based Materials for Sustainable Electronics and Functional Surfaces

Ramesh Adhikari, Colgate University

Over billions of years of evolution of life on earth has resulted in the existence of biological materials with a multitude of physical, mechanical, electronic, and optical properties. To address the problems associated with a growing amount of electronic and material waste, we have been working on developing low-cost, bio-based, and bio-degradable electronics and functional surfaces by taking advantage of the aforementioned properties of bio-based materials. Currently, our work has focused on using two specific bio-based materials - leaves and aromatic amino acids. Leaves are abundant, easily accessible, and are found with various surface morphologies and vascular architectures. By taking advantage of these properties, we have been developing various leaf-based electronic units such as wires, supercapacitors, and resistive memory devices. While leaves allow us to use the top-down approach in device fabrication, aromatic amino acids allow us to take the bottom-up approach. The charges and aromatic residues of aromatic amino acids make it possible for these amino acids to self-assemble in liquid or vapor environments and also interact with other polymeric systems. We have demonstrated that the natural aromatic amino acid phenylalanine can act as a dopant for commercially available conducting polymer PEDOT:PSS and help enhance the conductivity. We have also demonstrated that diphenylalanine, a peptide molecule with two phenylalanine units, can be self-assembled into vertically grown nanowires on fabrics which then can be used as an oil-water separating membranes. This talk will provide an overview of these developments.

November 7th

Summer Research Opportunities

January 9th

January 16th

January 23rd

January 30th

February 6th

John Wright, MIT

February 13th

February 20th

Tobias Schröder, University of Muenster

February 27th

Founder's Day (No Colloquium)

March 6th

John Hardin, MIT

March 13th

April 3rd

April 10th

April 17th

April 24th

May 1st

May 8th

No Colloquium (Steinmetz Symposium May 9th)

May 15th

May 22nd

Zhé-Yǔ Daniel Lín, Carnegie Science

May 29th

June 5th

Sigma Pi Sigma Induction

September 7th

September 14th

Student Poster Session

September 21st

Andy Dorsett, Mathematica

This technical talk will show live calculations in Mathematica 13 and other Wolfram technologies relevant to courses and research. Specific topics include:

* Enter calculations in everyday English, or using the flexible Wolfram Language
* Visualize data, functions, surfaces, and more in 2D or 3D
* Store and share documents locally or in the Wolfram Cloud
* Access trillions of bits of on-demand data
* Easily turn static examples into mouse-driven, dynamic applications
* Access 12,000 free course-ready applications
* Get deep support for specialized areas including machine learning, time series, image processing, parallelization, and control systems, with no add-ons required

Current users will benefit from seeing the many improvements and new features of Mathematica 13 (https://www.wolfram.com/mathematica/new-in-13/), but prior knowledge of Mathematica is not required.

September 28th

How to take a picture of a black hole

Dom Pesce

Center for Astrophysics | Harvard & Smithsonian, Black Hole Initiative at Harvard University

The Event Horizon Telescope (EHT) is a global array of radio dishes observing at a wavelength of 1.3 mm and designed to resolve the event-horizon-scale emission expected from the largest black holes in the sky. To date, the EHT has produced images of two black holes -- one in the center of the M87 galaxy, and the other residing at the heart of our own Milky Way -- in both cases revealing a compact and asymmetric ring of emission surrounding a dark central "shadow." The observed emission is consistent with expectations that it originates from strongly-lensed synchrotron radiation produced in a magnetized relativistic plasma surrounding the black hole, in which case the shadow then provides a direct window onto the event horizon itself. In this talk I will describe the telescope, data calibration, and downstream analyses that made these images possible, and I will discuss their implications for our understanding of supermassive black holes and general relativity.

October 5th

October 12th

October 19th

October 26th

November 2nd

November 9th

November 16th

January 4th

Summer Research Opportunities

January 11th

January 18th

January 25th

February 1st

February 8th

February 15th

February 22nd

February 29th

Founder's Day (No Colloquium)

March 7th

April 4th

April 11th

April 18th

April 25th

May 2nd

May 9th

No Colloquium (Steinmetz May 10th)

May 16th

May 30th

June 6th

Sigma Pi Sigma Induction

Thursday, Sept. 8th,

No Colloquium

Thursday, Sept. 15th,

Physics & Astronomy Summer Research Poster Session

Students that participated in the summer research program will present posters on their projects in the halls of the Physics & Astronomy Department. This is a great opportunity for students (and other interested people) to learn about some of the interesting research conducted in the department.

Thursday, Sept. 22nd,

No Colloquium

Thursday, Sept. 29th,

No Colloquium

Thursday Oct. 6th,

Making a Meson Factory: GlueX and the Eta Particle

Jon Zarling, Ph.D., University of Regina

The eta meson, a strongly interacting particle frequently produced at the GlueX experiment, offers a surprising range of physics insight. Studies of its decays offer a portal to search for hypothesized dark sector particles and helps constrain other beyond standard model (BSM) physics. Meanwhile, understanding how eta mesons are made at GlueX aids our understanding of the strong force, for instance giving us a peek deep into the proton. To date, the Virginia-based experiment has produced well over 10 million eta mesons. In this talk, I'll summarize measurements of the eta at GlueX so far, upcoming detector upgrades, and prospects farther into the future.

Friday, Oct. 14th,

GE Global Research

Joint seminar with Chemistry and Engineering, Olin 015

Thursday, Oct. 20th,

Enhancing Scientific Research Utilizing High-Performance & High-Throughput
Computing: An Overview With Uses In Nuclear & Particle Physics

Zach Baldwin, Carnegie Mellon University

Nowadays, everything is about speed and performance power. While laptops and smart devices have the ability to outperform humans, they are still limited in their abilities when it comes to extremely complex calculations or handling massive amounts of data. Since progress in science, within every field, requires these complex calculations and with an ever increasing amount of data gathered during experiments, there is a strong need for an increase in speed and performance power beyond what is currently being used. This talk will give an overview of how scientists are enhancing their research by tackling these issues directly through High-Performance Computing (HPC) and/or High-Throughput Computing (HTC). I will discuss in detail how each are performed respectively, as well as provide examples of how they both have been used within the nuclear & particle physics field along side my current research on the search for "exotic" states of matter.

Thursday, Oct. 27th,

T.B.D.

Thursday Nov. 3rd,

Physical and chemical properties at the surfaces of glass and their implications

Gabriel Agnello '00, Ph.D., Corning Inc.

Glass, which can be found in nearly every corner of our daily lives, is a notoriously difficult material to study due to its intrinsic energy state and lack of short, medium and/or long-range order. It stands to reason that the extension of a bulk system to termination at a surface would increase the complexity of this problem greatly. Today’s talk will be, in part, my brief attempt to decipher some of the main tenets of glass physics/chemistry while focusing particularly on considerations when dealing with the surfaces of glasses. Once some level of fundamental background has been established, we will discuss a specific, commercially relevant, glass surface related challenge in the flat panel display industry (triboelectrification, i.e. contact charging). The discussion will hopefully help to underscore the many difficulties involved in studying and ultimately understanding these types of systems.

Thursday, Nov. 10th,

Summer Research Opportunities

Prof. Nelia Mann

This is an informational session on summer research opportunities in the Department of Physics and Astronomy and off-campus REU programs.

Thursday, Jan. 5th,

Medical physics and proton therapy: what it is and what is coming next?

Yunjie Yang, Ph.D., Postdoctoral Researcher at the New York Proton Center

Modern medicine and patient care are becoming increasingly multidisciplinary. Countless medical devices are made possible because of innovations that stemmed from fundamental physics research, such as magnetic resonance imaging (MRI) and positron emission tomography (PET). In addition, many routine diagnosis and treatment procedures require highly trained professionals with corresponding physics expertise to support the day-to-day patient care, such as in diagnostic imaging and radiation therapy. In this talk, I will first give a general introduction to medical physics and proton therapy. I will then illustrate the roles of medical physicists in the context of radiation oncology. I will conclude with an overview of recent research and development in proton therapy, using examples at the New York Proton Center and beyond.

Thursday, Jan 12th,

How does DNA fold?

Ashley R. Carter, Ph.D., Amherst College

About 5 years ago, a colleague showed me this amazing image of a DNA molecule folded into a perfect toroid. "You literally just take DNA in a tube and add this one condensing agent. Then, presto, you get a toroid!" He exclaimed. I put down what I was doing and looked at the image more closely. "How?" I wondered. It is an interesting question. DNA is found in every living organism and must be folded in all of them. This folding into a toroid happens in sperm cells, but other compact forms of DNA in biology exist as well. People are also interested in how nucleic acids fold in viruses or in nanoengineering applications. So I wondered how does this condensing agent fold DNA into a toroid? What states, interactions, or mechanisms are at play? And, does knowing this physics give us any insight into how nucleic acids fold inside of an organism, sperm, or virus? Now, five years later, I'll tell you about some experiments we have done on single molecules of DNA to try to answer this question.

Thursday, Jan 19th,

Cutting-Edge Astrophysics with the NANOGrav Pulsar Timing Array

Thankful Cromartie, NASA Einstein Postdoctoral Fellow at Cornell

Pulsar timing array (PTA) collaborations are poised for the imminent detection of nHz-frequency gravitational waves emanating from an ensemble of supermassive binary black holes. From the perspective of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), I will discuss the landscape of low-frequency gravitational wave astrophysics: recent results, the incredible versatility of PTA data sets, and our vision for a next-generation detector. Specifically, I will detail the development of the upcoming NANOGrav 15-year data release and discuss the exciting synergistic science — including mass measurements that constrain the neutron star equation of state — that this data set has already facilitated.

Thursday, Jan. 26th,

Thursday, Feb. 2nd,

Tailoring spin waves in 2D magnetic materials

José J. Baldoví - University of Valencia

The recent isolation of two-dimensional (2D) magnets offers tantalizing opportunities for spintronics and magnonics at the limit of miniaturization. Among the key advantages of atomically-thin materials are their flexibility, which provides an exciting avenue to control their properties by strain engineering, and the more efficient tuning of their properties with respect to their bulk counterparts. In this presentation we will provide an overview of our recent results on this fascinating topic. First, we will focus on the magnetic properties, magnon dispersion and spin dynamics of the air-stable 2D magnetic semiconductor CrSBr (TC = 146 K) and will investigate their evolution under mechanical strain and Coulomb screening using first-principles. Then, we will apply our approach to some of the derivatives of the family of transition-metal phosphorus trichalcogenides and we will show the possibility of tuning spin wave transport by atomic-layer substitution, building a so-called Janus single-layer. Finally, we will introduce novel hybrid molecular/2D heterostructures using sublimable organic molecules to show, as a proof-of-concept, the potential of a chemical approach for magnon spintronics applications.

Thursday, Feb. 9th,

Brendan O'Connor '17, George Washington University

Neutron stars (NSs) are at the center of modern time domain astronomy (TDA). They are often invoked to explain the most luminous, and explosive transients, such as magnetar giant flares, superluminous supernovae, fast radio bursts, kilonovae, and gamma-ray bursts (GRBs). Throughout my PhD thesis, I have studied NSs both in our Galaxy and at cosmological distances, as these separate populations probe the formation and evolution of a variety of high energy transients. With regard to NSs in the Milky Way, I will present I will present the results of the Swift Deep Galactic Plane Survey (DGPS), a NuSTAR Legacy Project and Swift Key Project, comprising 40 sq. deg. of the Galactic Plane (GP) covering 10<|l|<30 deg and |b|<0.5 deg. The goal of the DGPS is to produce a rich sample of new sources and X-ray transients (e.g. NSs), while also covering a broad discovery space. I will then discuss my work on the host galaxies and environments of short GRBs. Short GRBs were unambiguously connected to binary NS mergers through the simultaneous detection of GW170817 and GRB 170817A. As such, short GRBs play a significant role in astrophysics with far-reaching implications, from the rate of detectable gravitational wave (GW) events to the production of heavy elements in the Universe. Their environments and distance scales yield important information as to their progenitors and their formation channels, complementing the constraints derived from GW astronomy. Throughout my thesis, I carried out an extensive observational campaign to study their host galaxies. I will present the results of my observations, including deep Gemini, Keck and HST imaging of 31 new short GRBs, doubling the previous sample of well-studied host galaxies.

Thursday, Feb. 16th,

Thursday, Feb. 23rd,

Exotic Mesons at the GlueX Experiment

Rebecca Barsotti, Indiana University

The Gluonic Excitations (GlueX) Experiment at Jefferson Laboratory is a particle physics experiment designed to search for and study exotic hybrid mesons. Through this, we hope to better understand the nature of the quantum chromodynamics (QCD) and confinement. We will discuss the motivation for these searches, the challenges faced, and the techniques used to look for these elusive hadronic states.

Thursday, March 2nd,

Thursday, March 9th,

Thursday, March 30th,

Thursday, April 6th,

Thursday, April 13th,

Thursday, April 20th,

Global Results on Exotic Hadrons

Dr. Will Imoehl, Carnegie Mellon University

The strong force has features that make it much more difficult to study than the electromagnetic and gravitational forces. One of the easiest ways to gain insight into the strong force is by observing how fundamental particles bind together. In particular, observing the spectrum of exotic hadrons can give us insight into the nature of the strong force. This talk will summarize the most recent results from the BESIII, Belle, LHCb, and GlueX experiments with regards to searching for exotic states. An emphasis will be given to the most well-established states, as well as those that are currently garnering a large amount of interest from theorists.

Thursday April 27th,

Thursday May 4th,

Friday, May 12th,

The 33rd Annual Steinmetz Symposium

Thursday May 18th,

Dr. Christine McCarthy, Columbia University, Lamont-Doherty Earth Observatory

Thursday May 25th,

Tuesday May 30th,

Sigma Pi Sigma Induction Ceremony

Thursday, Sept. 16

No colloquium

Thursday, Sept. 23

Physics & Astronomy Department Meet and Greet

Prof. Samuel Amanuel, Chair of the Department of Physics & Astronomy

This is an opportunity for students interested in physics and astronomy to meet and greet each other and the faculty in the department. Prof. Amanuel will introduce the faculty and staff and update everyone on what's happening in the department.

Thursday, Sept. 30

Physics & Astronomy Summer Research Poster Session

Students that participated in the summer research program will present posters on their projects in the halls of the Physics & Astronomy Department. This is a great opportunity for students (and other interested people) to learn about some of the interesting research conducted in the department.

Thursday, Oct. 7

The science in the art of roasting coffee beans

Prof. Samuel Amanuel, Union College

Globally over 2 billion cups of coffee are brewed and consumed every day. More often than not, however, the beans have to be roasted before brewing since most flavor and aroma compounds are developed during this process. During roasting, the beans undergo physical change while emitting sound and gasses. Because, these reflect the chemical changes, artisans have employed them as markers of roasting and degree of roasting in traditional and micro-roasting settings. In the industry, temperature-time profiles are heavily used to mark development of roasting and often are complemented by results from analytical instruments. We have used Thermogravimetric (TGA), Differential Scanning Calorimeter (DSC) and Infrared spectroscopy (FTIR) to trace the markers of roasting and develop understanding for the roasting reaction mechanisms. In this talk, I will discuss some of our findings and share our future directions.

Thursday, Oct. 14

Applied physics of ecophysiology: engineering lessons from bugs

Prof. Hunter King, University of Akron

Biomimicry promises to take solutions of the living world, developed through eons of environmental pressure and natural selection, and translate them to our own purposes. The prospect depends, however, on properly identifying the scientific principles underlying those solutions, which often cross disciplinary boundaries and hide beneath layers of complexity, leading to misunderstanding. I will present the role an experimental physicist can play in teasing out the abiotic mechanisms that connect bioinspiration to engineering, by way of our studies: of termite mounds which drive respiration from ambient thermal oscillations; of desert beetles which manipulate flow to catch fog droplets; and of mutualist epiphyte plant whose structure evolved to cater to the thermal needs of its ant hosts.

Thursday, Oct. 21

Climate Change and the En-ROADS Simulator; An Interactive Examination of the Effectiveness of Each Climate Change Action

Prof. Jon Marr, Union College

As the Earth has now warmed to more than 1.2o C above its pre-industrial temperature, and the catastrophic effects of climate change have become a reality, the world community needs the knowledge about what approaches can be done to successfully stop climate change. Climate Interactive, a not-for-profit think-tank formed out of MIT Sloan, has produced a free, publicly available on-line program called the En-ROADS Simulator which enables users to explore the impacts of every possible climate change action. I will introduce the simulator and we will use it to examine and discover what actions the world must pursue at this time.

Thursday, Oct. 28

A coarse-grained representation of DNA immersed in an external protein force-field

Prof. Cecilia Bores Quijano, Union College

DNA is often found in living cells forming complexes with other molecules. Despite their relevance in many biological processes, DNA complexes remain a challenge for simulation studies in molecular biology. All-atoms models suffer from high computational cost and are restricted to relatively small systems and short time scales; thus, coarse-grained models have emerged as a promising alternative. I will present you a novel coarse-grained model to simulate DNA interacting with a rigid protein. It consists in a mixed-scale representation coupling the oxDNA2 coarse-grained model for the nucleic acid with an atomistic model of an immobile protein. The simulation of many challenging biological systems ranging from the genome confined into the bacteriophages capsids or DNA surrounded by amino acids in crowded environments in the cell will benefit from this model.

Thursday, Nov. 4

Does Anybody Really Know What Time It Is? A Look At 5,000 Years of Timekeeping

Prof. Chad Orzel, Union College

We think of overscheduling and our obsession with timekeeping as a modern problem, but in fact the question of how to track and measure time has been a central preoccupation of every human civilization since the Neolithic era. In this talk, I'll discuss the science and technology behind some selected topics from the history of timekeeping, from solstice markers and water clocks all the way down to modern atomic clocks and GPS.

Thursday, Nov. 11

Alumni Panel Discussion

An informal discussion over Zoom with three alumni about their career paths and experiences. The panelists are: Morgan Clark (17) a graduate student in nuclear physics at the University of North Carolina in Chapel Hill; Steve Po-Chedley (08) a research scientist in the Atmospheric, Earth, and Energy Division of Lawrence Livermore National Laboratory; and Nicole Sabbatino (06) a physics teacher at Sewanhaka High School in Long Beach, NY.

Thursday, Nov. 18

Summer Research Opportunities

Prof. Nelia Mann

This is an informational session on summer research opportunities in the Department of Physics and Astronomy and off-campus REU programs.

Thursday, Jan. 6

No Colloquium

Thursday, Jan. 13

No Colloquium

Tuesday, Jan. 18

Direct detection of dark matter with XENON

Dr. Amanda Baxter, Purdue University

There is cosmological and astrophysical evidence which tells us that dark matter exists. The nature of dark matter is unknown as none of the standard model particles can explain it. The XENON experiments are built to search for signatures of dark matter scattering with a xenon target. The key to the success of the XENON experiments is the ability to understand backgrounds which may mimic the signature of dark matter. This talk will present results from XENON1T and will give the prospects for XENONnT to improve on the results found in XENON1T. Additionally, I will talk about how XENONnT can act as a neutrino detector with its ability to detect astrophysical neutrinos from the Sun and from supernova explosions.

Thursday, Jan. 20

Using Hadron Spectroscopy to Study the Strong Interaction

Dr. Colin Gleason, Union College

The strong interaction is the mechanism that binds quarks and gluons into hadrons and holds matter together through the strong force. In fact, this interaction is responsible for 99% of the mass of the visible matter in the universe. This talk will discuss how we can study the strong interaction through hadron spectroscopy at the GlueX experiment. GlueX is an experiment at Jefferson Lab in Newport News, VA whose goal is to create conditions where the gluons, which are typically "hidden" inside of hadrons, reveal themselves as equals to quarks. I will discuss how we can study these conditions by creating particles known as hybrid mesons. Finally, I will discuss contributions from undergraduates at Union to the experiment and give an overview of potential opportunities for undergraduate involvement.

Tuesday, Jan. 25

Particle Physics at the Precision Frontier

Dr. Kevin Labe, Cornell University

Last April the Muon g-2 Collaboration reported an exciting new measurement of the muon magnetic moment, which hints strongly toward new physics beyond the Standard Model. In this talk, I will explain why the muon magnetic moment is such a powerful tool for probing particle physics, how we measure it at high precision, and what it will teach us in the future.

Thursday, Jan. 27

Experimentally Probing the Hottest and Densest Matter on Earth

Dr. Timothy Rinn, Brookhaven National Laboratory

In relativistic heavy ion collisions, the highest temperature and most dense man-made material can be produced. At these temperatures and densities hadronic matter, such as protons and neutrons, break down forming a state strongly interacting deconfined nuclear matter called the Quark Gluon Plasma (QGP). The properties of this nuclear medium are studied utilizing a variety of both strongly and electromagnetically interacting probes. In this talk, I will focus on measurements using jets of high transverse momentum correlated particles produced by the fragmentation and hadronization of an initial quark or gluon. I will discuss recent experimental jet results from the ATLAS collaboration which provide key insight into the workings of this plasma. Additionally, I will highlight the exciting prospects for future insights to be gained from the under construction sPHENIX detector and the planned Electron Ion Collider facility.

Thursday, Feb. 3

“Sipping from the Holy Grail: Simulating the Self-Assembly of Nanoporous Solids”

Prof. Scott M. Auerbach, Department of Chemistry, Umass Amherst

Zeolites are the most used synthetic catalysts by weight on earth and offer the potential for new applications in carbon dioxide capture, green fuel production, and nano-electronics. The applications of zeolites arise from their nanoporous crystalline structures and stabilities. Despite the great importance of zeolites, those who fabricate zeolites still rely heavily on trial-and-error in their search for new materials, because the self-assembly mechanisms controlling zeolite formation remain poorly known. Elucidating such mechanisms will be critical to one of the &quot;holy grails&quot; of materials science – understanding the many-body collective phenomena (i.e., identifying the hierarchical building blocks) that control zeolite formation. Complicating such identification is the “nanoscale blind spot” that makes it challenging for characterization methods to reveal structure with atomic-level detail on the 5-10 nm length scale of zeolite crystal formation. In this lecture, we tell the story of a multi-scale molecular simulation program [1], informed by experiments, in search of this holy grail.

In the first part of the talk, we review zeolite science and synthesis approaches with a focus on the stages of assembly, and the roles of "structure directing agents" (SDAs) needed for pore formation. We study this problem through multi-scale applications of Density Functional Theory (DFT) and Monte Carlo (MC) simulations. In the second part, we present fundamental models of zeolite formation simulated with MC, yielding predictions of SDA sizes that optimize zeolite yield and crystallization rate, explained by SDA packing effects. We also show synthesis experiments testing these predictions, finding qualitative agreement but raising questions that require deeper study that we pursue with DFT calculations. In the third and final part, we discuss DFT simulations of Raman spectra of zeolites after and during formation, in search of building blocks of formation. We find that a “cubic” building block called the double-4-ring (or D4R) has a clear Raman signature that can be used to understand charge balancing and defect formation/healing during zeolite crystallization. Our work culminates in a “3rd route” to zeolite formation offering a new kind of defect engineering of zeolites.

[1] SM Auerbach, W Fan, and PA Monson, “Modeling the Assembly of Nanoporous Silica Materials”, International Reviews in Physical Chemistry 34, 35-70 (2015). (https://doi.org/10.1080/0144235X.2014.988038)

Thursday, Feb. 10

Biogeologic Carbon Capture and Sequestration - A Strategy that can Work

Prof. George Shaw, Union College

Photosynthetic organisms are the most efficient and cost-effective carbon capture entities on Earth. They have been doing this for billions of years. Among the most powerful are microalgae, especially cyanobacteria. Providing favorable locations for massive reproduction of microalgae could in principle halt, and probably reverse, the increase in atmospheric CO2. How and where to accomplish this is the outstanding question.

Thursday, Feb. 17

Raman effect: From a Laboratory in India to the surface of Mars

Dr. José Antonio Manrique, University of Valladolid, Spain

In this talk we will give an introduction to the Raman effect and how we use it to interrogate the microscopic state of matter. This tool has been deeply used by mineralogist and geologists for the characterization of Earth’s surface, and many other applications. Now thanks to current and future missions this technique is used, and will continue to be used in the future, by several planetary exploration missions.

SuperCam instrument (Mars 2020), in which I am collaborator, and RLS instrument (Exomars 2022), in which I am Co-Investigator, represent two different approaches on how to use Raman spectroscopy in space exploration. We will give a look at their design and some of the findings that already happened, along with the expected science from the RLS instrument.

Other Raman instruments, along with future developments will be covered in this talk as well.

Thursday, Feb. 24

No colloquium

Thursday, Mar. 3

No colloquium

Thursday, Mar. 10

No colloquium

Thursday, Mar. 31

No Colloquium

Thursday, Apr. 7

No Colloquium

Thursday, Apr. 14

Characterization of Novel Enr. 76Ge Detectors for the LEGEND-200 Experiment

Morgan Clark (U'17), UNC-Chapel Hill

Neutrinoless double-beta decay (0nbb) is a theorized rare decay in which two nuclei beta-decay at the same time emitting two electrons (positrons) and no anti-neutrinos (neutrinos). The discovery of 0nbb would provide scientists insight into lepton number violation and the nature and mass of the neutrino and would have major implications in nuclear and particle physics. The Large Enriched Germanium Experiment for Neutrinoless double-beta Decay (LEGEND) is pursuing a phased approach to develop a ton-scale experiment searching for 0nbb in 76Ge. The experiment builds on the successes of two previous 0nbb experiments, the MAJORANA DEMONSTRATOR and the GERDA experiment. The first phase, LEGEND-200, is currently being built at Laboratori Nazionali del Gran Sasso (LNGS) in Italy and will take commissioning data later this year. The experiment utilizes a 200-kg array of 76Ge detectors submerged in liquid argon. ~140-kg of these detectors are being fabricated for LEGEND in the novel Inverted Coaxial Point Contact (ICPC) geometry developed specifically for this experiment to increase the mass of the detectors without sacrificing the excellent energy resolution and pulse shape discrimination properties of the MAJORANA and GERDA style PPC detectors. Before the detectors can be deployed, they need to be fully characterized. We use a 228Th source to measure each detector’s efficiency, energy resolution, and timing response and take additional radial and longitudinal scans with 241Am and 133Ba sources to determine the dead-layer of the detectors. This talk will focus on the characterization process of these new detectors in Oak Ridge, TN and some recent results.

Thursday, Apr. 21

Slowing and cooling molecules by applying multiple laser colors: exploring the optical bichromatic force

Dr. Leland Aldridge, Gonzaga University

Atoms and molecules can exchange both energy and momentum with the electromagnetic field and be slowed or cooled by the interaction. A single frequency of laser light can be used for slowing, but there are limits on the resulting force, based on intrinsic photon scattering rates. Using as few as two laser frequencies, these limits can be surpassed by harnessing stimulated emission of photons, as in a particular scheme called the bichromatic force. This talk introduces the bichromatic force and presents computational studies of its application to molecules and of its curious cooling effects.

Tuesday, Apr. 26

Substructure Formation in Protoplanetary Disks

Dr. Scott Suriano, SUNY Corning Community College

Observations from ALMA have changed the framework for how we look at
protoplanetary disks. Instead of smooth accretion disks, we now know of intricate disk substructures, concentric bright rings and dark gaps, warps and azimuthal asymmetries, inner disk misalignments and cavities. As the observational inventory grows, an important theoretical question still remains: are we observing planet formation in the works, or are we observing the dynamical imprint of previously formed planets? In this talk, I will discuss how the vertical magnetic fields that thread protoplanetary disks and launch magnetic disk winds can lead to the formation of rings and gaps through 3D MHD simulations. If magnetic fields are able to form disk substructure early in disk lifetimes, dense rings could be the preferred locations of dust grain trapping and the site of planetesimal growth.

Thursday, Apr. 28

The Nearest Mid-to-Late M dwarfs and Their Stellar, Brown Dwarf, and Exoplanetary Companions

Dr. Jennifer Winters, Center for Astrophysics | Harvard & Smithsonian

M dwarfs with masses 10% < solar mass < 30% are under increasing scrutiny because these fully convective stars afford the most accessible near-future opportunity to study the atmospheres of terrestrial planets. Our knowledge of these precious planets depends critically upon understanding their faint host stars. I will discuss our volume-complete, all-sky sample of 512 M dwarfs with masses 10% < solar mass < 30% and with trigonometric distances placing them within 15 pc from which we have created a sample of 413 M dwarfs for spectroscopic study. I will then go on to describe our efforts to identify and discover the very closest companions to these stars. Finally, I will highlight LTT 1445, a stellar triplet at 7 pc, which is the nearest M dwarf system known to host transiting, rocky exoplanets.

Thursday, May 5

Towards 3D Imaging of the Nucleon

Dr. Salina Ali (U'15), University of Virginia

Understanding the structure of the nucleon (proton or neutron) in terms of its most basic constituents, the quarks and gluons, is one of the main thrusts of twenty-first century physics research. Just as the earth orbits around the Sun while simultaneously spinning about its own axis, the quarks and gluons in a proton could have linear motion, orbital motion, and spin – the latter two responsible for the overall proton spin that is exploited daily in thousands of MRI images worldwide. Experimentally, one cannot isolate the quarks and gluons, but one can infer their properties from experiments on nucleons, i.e. protons or neutrons. High-energy electron beam experiments leading to a final state of a completely-measured set of only a few particles allow to image the deep inside structure of the nucleon. This is the topic of a new science direction termed "nuclear femtography". In this talk, I will discuss exclusive reactions, processes in which the deep inside of the nucleon is studied with a highly-energetic electron probe by a completely-measured set of only a few particles, e.g. a neutral pion or photon. The upcoming Jefferson Lab Hall A spectator tagged physics program includes a measurement of exclusive tagged neutron-Deeply Virtual Compton Scattering (n-DVCS), shedding light on the neutron structure through the spectator tagging technique. This measurement will depend on a multi-Time Projection Chamber (mTPC) device used to detect low-momentum particle tracks in extreme high background rate conditions. I will describe the experimental setup in Hall A of Jefferson Lab, prospects of the n-DVCS measurement, and the status of the mTPC detector.

Thursday, May 12

Ion Production and Mitigation in DC High-Voltage Photo-guns

Dr. Josh Yoskowitz (U'16), Old Dominion University

One of the biggest obstacles to operating a GaAs polarized electron source with a long charge lifetime is the mitigation of ion back-bombardment. Several techniques exist either to clear ions from the accelerator or to mitigate ion damage of the photocathode. Predicting the effectiveness of these techniques requires sophisticated simulation models of electron impact ionization within the photo-gun. In this work, the effectiveness of applying a positive anode bias voltage to mitigate ion damage and increase the lifetime of the GaAs photocathode was studied over three run periods at the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab). The charge lifetime with the biased anode configuration was 1.80 times greater than the lifetime of the usual grounded anode configuration. Simulations of ionization within the CEBAF photo-gun and adjacent beamline were made using General Particle Tracer (GPT) and a new C++ custom element to predict and explain the substantial improvement in charge lifetime. The experimental results will be described in detail and the development of the ionization custom element and its use in simulations of ion back-bombardment with the biased anode will be presented.

Thursday, May 19

How contribution of higher-order proximal distribution functions influence the solvent structure

Dr. Raziyeh Yousefi, UTMB-Galveston

The proximal distribution function (pDF) systematically identifies the solvent structure around solutes from a knowledge of molecular distribution functions based on the proximity criterion as the key element. Previously, pDFs considered the contribution of the nearest neighbor distribution only. Here, the pDF reconstruction algorithm is extended to terms including next-nearest neighbor contribution as well. Small solute molecules (including alanine and butane) are examined. Further, the analysis is extended to include the myoglobin P6 unit cell, in which 6 myoglobin proteins are fully packed. To justify the results, molecular dynamics (MD) simulations are performed and solvent number density distribution around the solute molecules are derived and compared with the results from the nearest+next-nearest neighbor pDF reconstruction model. It is shown that this modification improves the reconstruction of the solvent number density distribution in the near vicinity of solute molecules. Finally, it is shown that solute-solvent van der Waals (vdW) and electrostatic interaction energies are in fairly good agreement with the simulated values.

Thursday, May 26

Unveiling Dark Energy with Millions of DESI Spectra

Prof. John Moustakas, Siena College

Elucidating the nature of dark energy and the physical mechanisms responsible for the accelerating expansion of the universe is one of the most important outstanding problems in (astro)physics. To tackle this question, in May 2021 the Dark Energy Spectroscopic Instrument (DESI) collaboration began a 5-year spectroscopic survey to produce the most detailed three-dimensional map of the universe. By measuring the baryon acoustic oscillation (BAO) feature and redshift space distortions at multiple cosmological epochs, DESI will place unprecedented constraints on the equation of state of dark energy and yield transformative insights into the formation and evolution of galaxies and quasars over eighty percent of cosmic time. In just its first year of science operations, DESI has measured precise redshifts for nearly 13 million extragalactic targets, making it the largest spectroscopic redshift survey ever conducted. In this talk, I will discuss the scientific motivation and current state of the DESI Survey, present some preliminary scientific results, and describe the timeline for the key papers and public release of the DESI data.

Thursday, Jun. 2

Sigma Pi Sigma Induction Ceremony

Thursday, Sep 12

No colloquium

Sep 19

Physics & Astronomy Summer Research Student Poster Presentation

Thursday, Sep 26

Research Opportunities at Argonne National Lab and Lowering the Uncertainty of the "Triple Alpha Process"

Jeremy Smith (U'14)
Department of Physics, University of Connecticut

Argonne National Lab (ANL) has many research opportunities from biology and chemistry to nuclear physics and material science. My talk will focus on the different research facilities at the Argonne Tandem Linac Accelerator System (ATLAS) such as Gammasphere, MUSIC and the Canadian Penning Trap as well as my specific research which uses ANL's Helical Orbital Spectrometer (HELIOS) to lower the uncertainty of the "Triple Alpha Process". The triple alpha process is a very important process that is the very first stages of nucleosynthesis that occurs in stars. It is so important that life as we know it would not exist if not for this process and knowing the rate of this process accurately is important in determining many stellar measurements such as the size of supernova's produced from Asymptotic Giant Branch (AGB) stars. The task of lowering the uncertainty of this rate was first started about 10 years ago at HELIOS and I will be talking about the results of this first experiment along the methods used. Our aim is to make adjustments to this first attempt using a different experimental setup and "inverse kinematics" along with many added "upgrades" to HELIOS itself in order to get a more accurate measurement of this very important number.

Thursday, Oct 3

Not Your Grandpa’s Theory of Everything

Sophia Domokos
Department of Physics, New York Institute of Technology

What is string theory? Why does it remain such an active area of theoretical physics research? In this talk, I will give a broad overview of string theory as a mathematical framework that encompasses myriad physical (and mathematical) phenomena. I will focus on how string theory’s extra dimensions geometrize particles’ inherent traits (like mass and spin), and how powerful tools called “dualities” may help us understand physical systems from the protons and neutrons in each atomic nucleus, to the mysterious interiors of black holes.

Thursday, Oct 10

The Exotic Nature of Matter: From Pentaquarks to Hybrids

Colin Gleason (U'11)
Department of Physics, Indiana University

In the 1960s, Murray Gell-Mann developed a simple model to describe the basic properties of hadrons, which are particles constructed from quarks and held together by gluons. Hadrons primarily come in two types: mesons which are composed of a quark antiquark pair and baryons, such as the proton and neutron, which are composed of three quarks. Gell-Mann's quark model did a remarkable job of classifying and predicting hadrons from their quark content alone while not factoring in the role of gluons. These simple configurations dominate what we see in nature, yet nothing in the theory of the strong interaction forbids more “exotic” states of matter. In fact, recent theoretical predictions and new observations at experimental facilities around the world are beginning to shed light on a richer spectrum of hadrons. This richer spectrum includes hybrid mesons, particles where gluons are on the same footing as quarks and cannot be built in Gell-Mann's simple quark model, tetraquarks, pentaquarks, and hadronic molecules. This talk will introduce how these particles can be theoretically formed and experimentally measured, then present recent results and potential candidates for these exotic states of matter. I will discuss the global effort to search for these particles: from potential pentaquarks at the Large Hadron Collider, to tetraquarks and/or hadronic molecules at the Beijing Spectrometer, to hybrid meson searches ongoing at Jefferson Lab in Virginia.

Thursday, Oct 17

No colloquium

Thursday, Oct 24

Complex Applications with Simple Atoms

Charlie Doret

Department of Physics, Williams College

Improvements in control over the quantum states of physical systems during recent decades have given rise to a wealth of applications. Atomic clocks have long served as the heart of the Global Positioning System. More recently, atomic systems have been used to make superb sensors of electromagnetic fields, accelerations, and rotations. Coherent control of the quantum states of individual atoms has also brought us to the brink of solving problems which are intractable on ordinary, classical computers, and enabled precision measurements which probe our understanding of physics with of heretofore unheard of sensitivity. In this colloquium I will give a broad introduction to the application of atomic systems to timekeeping, precision sensing, and quantum information processing. I will also discuss two experiments with trapped atomic ions underway at Williams: quantum simulation of nanoscale heat transport using the vibrational modes of trapped atomic ions, and precision measurements of isotope shifts which may offer insight into new physics beyond the Standard Model.

Thursday, Oct 31

Neutrinos matter. Can nEXO show that they antimatter too?

Ethan Brown

Department of Physics, Applied Physics, and Astronomy, RPI

The discovery of neutrino mass is the only observed phenomenon that contradicts the standard model of particle physics. The explanation of the origin of the tiny neutrino masses poses an incredible hypothesis: what if neutrinos and antineutrinos are the same? This would have groundbreaking implications for matter generation, and could explain the matter-antimatter asymmetry observed in the universe. It also predicts a rare nuclear decay, neutrinoless double beta decay, with a half life of at least 10^26 years. The nEXO experiment aims to detect this rare decay and shed light on the mysterious neutrino, potentially proving that matter and antimatter can be one and the same particle.

Thursday, Nov 7

Sculpting high aspect ratio crystals from an oil in water emulsion

Mathew Giso (U'16)

Department of Physics and Astronomy, Tufts University

High aspect ratio crystals have a wide variety of applications and there are many ways to make them. To be useful, creating these crystals needs to be easy outside of a lab setting and how the important parameters control the system needs to be well understood. The behaviors of even simple systems can be dramatically changed with a small change in the ingredients. A mixture of oil and water is simple enough. If it is cooled, you will end up with frozen droplets of oil. By adding a surfactant, a kind of soap, we can induce these oil droplets to deform as they freeze creating long crystals. It turns out these kinds of crystals are very effective for drug delivery. We simulate this process using a numerical model which can capture the freezing and deformation behavior seen in experiment. Our results reproduce the wide ranges of shapes seen in experiment and provide insight into controlling their final morphology.

Thursday, Nov 14

INNOVATION, INTELLECTUAL PROPERTY & ENTREPRENEURSHIP LAW

Shahrokh Falati, Ph.D., J.D.
Professor & Director of Programs for Intellectual Property, Tech. Transfer, Innovation & Entrepreneurship Law, Albany Law School

Bio: Shahrokh (Seve) Falati’s area of legal expertise includes Patent Law; Trademark & Unfair Competition Law; Intellectual Property Law; and the interdisciplinary legal fields governing legal representation of entrepreneurs and innovators (aka Entrepreneurship Law). Prof. Falati is the Director of Programs for Intellectual Property, Technology Transfer & Entrepreneurship Law at Albany Law School. Prior to joining the faculty at Albany Law School, for over a decade, Professor Falati worked in private practice, focusing exclusively on representing clients on Intellectual Property Law and related legal matters at two large prominent law firms in New York (Jones Day, and HRFM). He maintains a small private practice. He is admitted to practice law in New York and Massachusetts, before the United States District Court for the District of Massachusetts, and as a registered patent attorney before the United States Patent & Trademark Office.

Thursday, Jan 9

Summer Research Opportunities

Jef Wagner

Department of Physics and Astronomy, Union College

This is an informational session on summer research opportunities in the Department of Physics and Astronomy and off-campus REU programs.

Thursday, Jan 16

Joint Colloquium with the Health Professions Program

My Journey in Becoming a Hand and Upper Extremity Surgeon

Bilal Mahmood, M.D. (U'08)

Assistant Professor, Department of Orthopaedics, University of Rochester Medical Center

At Union, I majored in Mathematics and Physics. I've always considered the purity of mathematics unrivaled in all the sciences, with physics its closest sibling. The physics department remained home-base, thanks in large part to the welcoming nature of Colleen Palleschi, the department's administrative assistant. I was privileged to do research with Professors Koopmann and Newman, and truly enjoyed my time in the department. I decided to pursue medicine while a second year. It wasn't until the beginning of fourth year in medical school that I settled on Orthopaedic Surgery. Once in residency, it did not take long to focus in on Hand Surgery as a subspecialty. Formalized in World War II, Hand Surgery developed as a distinct subspecialty because of the mixture of orthopaedics, plastics, general surgery, neurosurgery, vascular surgery, micro surgery, and even psychiatry involved. A hand surgeon is responsible for the musculoskeletal system, soft tissue, vascular system, and peripheral nerves. The idea of being fully responsible for one part of the body and providing complete care was my reason for choosing Hand Surgery. In this talk, I will share my journey in becoming a hand surgeon. I will show my day to day life, and show common as well as interesting cases in Hand and Upper Extremity Surgery.

Thursday, Jan 23

Quantum bubbles in space: ultracold atomic physics aboard the International Space Station

Nathan Lundblad

Associate Professor, Department of Physics and Astronomy, Bates College

In 2018 NASA sent an instrument to the International Space Station to study the physics of matter cooled well below a millionth of a degree above absolute zero. Built by NASA scientists at the Jet Propulsion Laboratory in California, installed by astronauts in orbit, and used by physicists around the world, the Cold Atom Laboratory (NASA CAL) is focused on studying what happens when you remove gravity as a perturbing influence on refrigeration experiments like those conducted in hundreds of terrestrial labs. In particular, an exotic state of matter known as a Bose-Einstein condensate (BEC), first observed on Earth in 1995, has now been observed in space, with several key open questions now open to investigation regarding the behavior of BECs in microgravity.

One particular avenue of investigation focuses on whether BECs can be formed in the shape of a bubble: a radically different topology for trapping that can strongly affect the thermodynamics of the BEC, the collective motion of the BEC, and the dynamics of quantum vortices. This presentation will review the NASA CAL instrument, student research with CAL at Bates College, and progress toward observations of ultracold bubbles.

Thursday, Jan 30

Over the Horizon: The Department of Energy and the Future of Solar Technologies

Garrett Nilsen (U'05), U.S. Department of Energy

Solar technologies are evolving quickly, from cells and modules to system-level innovations and storage. In the next decade, the U.S. Department of Energy Solar Energy Technologies Office expects to see this rapid technology development continued, reaching the energy market and beyond (such as solar desalination). The office funds early-stage technology research with an eye towards what technologies will help to keep the U.S. solar industry on the leading edge. Garrett Nilsen, Technology to Market Program Manager and Active Soft Costs Program Manager in the Solar Energy Technologies Office (SETO) at the Department of Energy, will discuss his career since leaving Union College (class of 2005), the Department of Energy and SETO’s role in technology development and the future of solar energy technology in the United States.

Thursday, Feb 6

Silicon-based Integrated Photonics: Basic building blocks and the role of variations in device performance

Robert Geer

Professor of Nanoscale Science, SUNY Polytechnic Institute

The success of Si as a platform for photonic devices and the associated availability of wafer-scale, ultra-high resolution lithography for Si CMOS has helped lead to the rapid advance of Si-based integrated photonics manufacturing over the past decade. This evolution is nearing the point of integration of Si-based photonics together with Si-CMOS for compact, high speed, high bandwidth, and cost-effective devices.

However, due to the sensitive nature of passive and active photonic devices, variations inherent in wafer-based fabrication processes can lead to unacceptable levels of performance variation both within a given die and across a given wafer. Fully understanding the role of variation in affecting integrated photonic device performance is an important component of scaling the design and manufacturing infrastructure for photonic integrated circuits.

This seminar will provide an introduction to Si-based integrated photonics and review the basic operation of Si-based integrated photonic devices. In addition, results will be presented regarding the impact of intra- and inter-die variation on integrated photonic device performance based on customized structures fabricated at SUNY Poly’s AIM Photonics Center.

Thursday, Feb 13

Air Quality Measurements in Uganda

Beth Parks

Department of Physics & Astronomy, Colgate University

Airborne particulates are a major component of air pollution. Ambient (outdoor) particulates are estimated to cause 3 million premature deaths annually worldwide, with an additional 4.3 million deaths due to the indoor environment. Particles with aerodynamic diameters under 10 microns (PM10) can reach the lungs, and those under 2.5 microns (PM2.5) can reach the bloodstream. Exposure to airborne particulates is linked to a wide range of cardiovascular problems. In developed nations, particulate levels are routinely monitored, and when they exceed threshold levels, warnings are issued and activity restrictions are implemented to reduce them. However, in most developing countries, there is no government monitoring, and a lack of data will hamper future efforts to study the effects and mitigate the most important sources.

Long-term particulate matter (PM10) measurements were conducted during the period January 2016 to September 2017 at three sites in Uganda (Mbarara, Kyebando, and Rubindi) representing a wide range of urbanization, and during both wet and dry seasons. Particulate matter (PM10) samples were collected for 24-h periods on PTFE filters using a calibrated pump and analyzed gravimetrically to determine the average density. Particulate levels were monitored simultaneously using a light scattering instrument to acquire real time data from which diurnal variations were assessed. The PM10 levels averaged over the sampling period at Mbarara, Kyebando, and Rubindi were 5.8, 8.4, and 6.5 times higher than the WHO annual air quality guideline of 20 μg·m−3, and values exceeded the 24-h mean PM10 guideline of 50 μg·m−3 on 83, 100, and 86% of the sampling days. Higher concentrations were observed during dry seasons at all sites. Seasonal differences were statistically significant at Rubindi and Kyebando. Bimodal peaks were observed in the particulate levels as a function of time of day with higher morning peaks at Mbarara and Kyebando, which points to the impact of traffic sources, while the higher evening peak at Rubindi points to the influence of dust suspension, roadside cooking and open-air waste burning. Long-term measurement showed unhealthy ambient air in all three locations tested in Uganda.

Thursday, Feb 20, at 4:00 PM

Medical Physics in Radiation Oncology

Tom Mazur (U'07)

Department of Radiation Oncology, Washington University School of Medicine in St. Louis

Applications of physics pervade medicine. Contemporary “Medical Physics” refers mostly to careers in nuclear medicine, radiology and radiation oncology departments that provide support for the safe and effective delivery of radiation to cancer patients for both diagnostics and therapy. Day-to-day responsibilities specifically in radiation oncology can be highly variable and diverse. Medical physicists provide support in nearly all aspects of a patient’s treatment including “simulation” CT and MRI imaging prior to treatment, treatment planning where radiation is designed to achieve a physician’s prescription, and radiation delivery (e.g. at a linear accelerator, brachytherapy procedure, or radiopharmaceutical administration). Beyond patient treatments, physicists implement new tools and technologies into clinics and ensure the equipment and procedures in use maintain high quality standards. Through these core responsibilities, opportunities arise for innovating and implementing novel technologies that can contribute toward improving outcomes for cancer patients. Medical physics thus is a unique field that combines a day-to-day job with core responsibilities with impactful research opportunities. In this talk, I will describe careers in medical physics, including necessary pre-requisites and training, day-to-day responsibilities, various technologies, and opportunities for research.

Thursday, Feb 27

Physics and material science of blood: from insects to humans

Pavel Aprelev (U'13)

University of Pennsylvania School of Medicine

Physics is an excellent tool to study the world around us. When physics is applied towards understanding of materials, it is called materials science. Some materials are artificial, some occur naturally; but everything around us is made out of these materials. In this seminar, a Union College physics alum will talk about how he used the skills he acquired in the physics classroom at Union to study various biological and artificial liquid materials. He will discuss the discoveries he made in the materials science of clotting insect blood to get his PhD. He will also discuss how he is using physics currently to advance the groundbreaking research in the field of nanomedicine.

Thursday,, Mar 5

Theoretical Physics of Viruses

Jef Wagner

Department of Physics and Astronomy, Union College

Viruses are small biological agents that replicate using the machinery already present in a living cell. As we have all experienced when viruses infect the cells of an organism, the organism (i.e. you) get sick. But viruses can be used for more than just making you sick. The virus's ability to infect and deliver a cargo into a cell has been used for targeted drug delivery and gene therapy. Understanding how viruses work at a fundamental level can help both understand treatment for viral infections as well as engineer novel uses for viruses going forward. In this talk, I will show how we can use the tools of mathematics and theoretical physics to model the fundamental behavior of viruses.

Thursday, Mar 12

YORP Unexpectedly Revealed: Science from Asteroid Lightcurves

Stephen Slivan

Massachusetts Institute of Technology

Asteroids represent relatively primitive material in the solar system, and thus can provide information related to solar system formation that is unavailable from studying the larger planets. However, the asteroids have experienced evolution processes of their own, and understanding those processes is important to unraveling information about the past from observations of the asteroids as they are today. I will describe how a long-term observation program that was conducted mainly from three different small telescopes in the Northeast
inventoried the spin properties of members of the Koronis family of asteroids, surprised asteroid experts by revealing the previously unsuspected effect of a spin evolution process now known as YORP, and how ongoing observations continue to be a source of projects that are well-suited to undergraduates learning astronomy hands-on at teaching observatories.

Thursday, April 16, Virtual Colloquium via Zoom

A Guide for Using Dead Stars to Find Black Holes: Detecting Gravitational Waves with Pulsar Timing Arrays

Brent Shapiro-Albert (U'16)

West Virginia University

Pulsars are rapidly rotating neutron stars with extremely stable periodic radio emission. The radio emission from some pulsars is so stable that it can be measured and predicted down to sub-microsecond timescales, making them some of the best clocks in the Universe. There are many interesting experiments and tests of fundamental physics that can be done with pulsars, including using an array of millisecond pulsars spread across the galaxy (known as a pulsar timing array) to detect ripples in spacetime from gravitational waves. These gravitational waves are likely emitted by supermassive black hole binaries at the center of galaxy mergers spread across the Universe. In this talk I will discuss the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) group’s current efforts to detect these gravitational waves, including an overview of how NANOGrav uses millisecond pulsars to look for gravitational waves, and in particular focus on the various noise processes that are part of our galaxy sized gravitational wave detector. I will also show the current best results from the NANOGrav collaboration and discuss future prospects for detection.

Thursday, April 23

No Colloquium

Thursday, April 30

The Quantum Physics of an Ordinary Morning

Chad Orzel

Department of Physics & Astronomy

Union College

We tend to think of quantum mechanics as an abstract and arcane area of physics that only applies in the exotic situations found in physics labs, billion-dollar particle accelerators, or near black holes. In fact, though, the development of quantum physics has its roots in very mundane, everyday phenomena. In this talk, I'll describe how quantum physics manifests in the kind of situations you regularly encounter in the course of getting up and getting ready to face the day.

Thursday, May 7

No colloquium (Steinmetz week)

Thursday, May 14, Virtual Colloquium via Zoom

Student Presentations

Isothermal Crystallization of Poly(Vinyl Alcohol-co Ethylene)

Jillian Guthrie (U'20)

Isothermal crystallization of the copolymer Poly(Vinyl Alcohol-co-Ethylene) was studied, with an ethylene content of 27%. Using a differential scanning calorimeter (DSC), the copolymer was crystallized between 160 and 180 degrees C. The crystallization kinetics were analyzed using the Avrami and Hoffman-Weeks methods. The overall morphology and crystal growth were determined from fitting parameters.

Turbulent Flow Over Homogeneous Canopies with Gaps of Various Lengths

Adam Peterlein (U'20)

The fluid flow within a canopy of uniform, densely packed elements containing a gap of various length was measured using planar particle image velocimetry. The model was submerged within a water channel in an open channel configuration with a flow depth three times the height of the canopy. The canopy included a gap which measured 0.5, 1, 2, 3, or 4 times the canopy height. The Reynolds number based on the submergence depth of the flow was found to be 12,600. Based on mean flow quantifications and turbulence statistics, the flow within the gap was found to fall into two regimes based on the ratio of the gap length to gap height. For the short gap regime, the shear layer at the top of the gap does not experience vertical growth and therefore the turbulence does not penetrate into the gap; however, for the long gap regime, the shear layer experiences significant vertical growth and enhances mixing within the gap. When compared to a solid cavity, significant differences are found in the behavior of the shear layer that develops at the top of the gap. Finally, a fluctuating velocity cross-correlation was preformed to analyze the structure of vortices across the top of the canopy and over the canopy gap and additional differences were noted in the development of vortical structures over the gap when compared to the solid cavity.

Rutherford Backscattering Spectrometry of Lead-Iron Diffusion

Jack Schlater (U'20)

Accurate constraints of the diffusion closure temperature in radioisotope thermal-chronometers of early Solar System allow for greater accuracy in the dating of rocky bodies. These closure temperatures can be estimated based on the composition and geometry of the body, along with information about the diffusion coefficient and activation energy of the specific radioisotopes inside the body. Thin film diffusion experiments were performed on nine samples of pure iron pellets coated with 100nm of lead. These samples were subjected to heating at either 600°C for up to ten days, or 750°C for up to twenty-three hours, allowing for sufficient diffusion of the coating into the medium. The diffused samples were analysed at the University of Albany Ion Beam Laboratory using Rutherford Backscattering spectrometry (RBS). RBS spectra were processed using SIMNRA, an ion beam analysis program for Windows, to generate concentration profiles of the diffused lead. These profiles were fit to the thin-film solution to Fick's Second Law linear diffusion equation, returning diffusion coefficients for Pb in Fe 600°C and 750°C. Our results give an activation energy of 364±53 kJ/mol, within reason of expected values for diffusion in metals. This information can be used in tandem with other work in this ongoing project.

Thursday, May 21

No colloquium

Thursday, May 28

Probing the organization and dynamics of two DNA chains trapped in a nanofluidic cavity

Xav Capaldi (U'16)

Department of Physics

McGill University

Using familiar principles from classic soft-lithography devices, we have developed a pneumatically-actuated nanofluidic platform that has the capability of dynamically controlling the confinement environment of macromolecules in solution. The system uses pneumatic pressure to deflect a thin nitride lid into a nanoslit, confining molecules in an array of cavities embedded in the slit. We use this system to quantify the interactions of multiple confined DNA chains, a key problem in polymer physics with important implications for nanofluidic device performance and DNA partitioning/organization in bacteria and the eukaryotes. In particular, we focus on the problem of two-chain confinement, using differential staining of the chains to independently assess the chain conformation, determine the degree of partitioning/mixing in the cavities and assess coupled diffusion of the chain center-of-mass positions. We find that confinement of more than one chain in the cavity can have a drastic impact on the polymer dynamics and conformation.

Thursday, June 4

Sigma Pi Sigma Induction

Colloquium Schedule

Thursday April 4, 2019

1st week of classes: no seminar

Math, ECBE, Physics and Astronomy joint seminar

Thursday April 11, 2019

during common hour

Karp 005

Towards Cyber-Physical Electrical Power Systems: where the laws of nature and the rules of algorithms collide!

Luigi Vanfretti
Electrical, Computer, and Systems Engineering, RPI

Electrical power networks are undergoing unprecedented changes. On one hand, the adoption of distributed energy resources (DER) and renewable energy sources (RES), both of which have a large degree of variability in small time-scales, puts challenges to the traditional, historical-and-experience-based design and operation of electrical power networks. On the other hand, digitization and automation, opens opportunities for a more carbon neutral electrical energy system by helping to harmonize these new energy sources with the rest of the power grid, not without also bringing along the potential threats of the cyber world. This talk aims to give an overview of these challenges, and to present different research efforts conducted by the presenter to address how to transform today’s electrical grid into a cyber-physical power system. This includes the development of an experimental facility to conduct, real-time hardware-in-the-loop simulation experiments of power networks with “cyber” assets. This approach allows to characterize how the interaction of systems governed by the laws of nature will interact with engineered systems governed by rules of algorithms. Finally, with the rise of electrification in transport, and in particular aircraft, and the rise of more autonomous machines, the talk will also discuss the need for development of a new course on modeling and simulation for cyber-physical systems (CPS) and the teaching approach adopted which brings a “digital” toolbox and know-how to the next generation of electrical engineers that will have to increasingly deal with complex CPS.

Please note the new location: Karp 005

Thursday April 18, 2019 during common hour in S&E N304

The dark side of the force: searching for dark sector physics

Andre Sterenberg Frankenthal, Cornell University

Dark matter is one of the greatest puzzles facing physics today. Our attempts to find a dark matter particle have so far come up empty-handed, and the theoretical models that have guided these efforts for the last 30 years are increasingly suspect. We still have few clues as to its nature. In this talk, I will explore two new and complementary experimental methods to look for evidence of a dark sector which are currently underway. Both methods search for the hypothetical dark photon, a mediator of a fifth force similar to ordinary electromagnetism that could provide the long-sought bridge between ordinary and dark sector physics. I will discuss prospects for the two experiments, experimental challenges, and perspectives for future dark matter-related new physics efforts.

Thursday May 2, 2019 during common hour in S&E N304

COMPRES lecture in Geophysics:Core Crystallization and its Impact on Planetary Cooling

Anne Pommier
Scripps Institute of Oceanography, UC San Diego

Core crystallization is a crucial ingredient in the evolution of terrestrial planets and moons and is controlled primarily by chemistry and temperature. Crystallization within a metallic core releases latent heat and gravitational energy, influencing significantly the processes responsible for the presence of a magnetic field. The diversity of magnetic fields observed in small terrestrial bodies, such as the Moon, Mars, Mercury or Ganymede suggests different core cooling history. Past space missions have observed that Mars and the Moon do not currently possess an internally-generated magnetic field but likely had one early in their history, while Mercury currently possesses a weak magnetic field and Ganymede is characterized by a strong one. The origin of this diversity is not well understood and seems to depend highly on the onset, depth, and rate of crystallization. This presentation will focus on the effect of chemistry on core crystallization and its implications for the magnetic field. All results will be compared to the magnetic history and available observational constraints on the core structure, temperature and composition of Mars, the Moon, Mercury and Ganymede.

Thursday May 16, 2019 during common hour in S&E N304

Supporting the Advances in Nanoscale Science and Engineering

Jason E. Sanabia, Ph.D.
President & CEO, Raith America, Inc.

My appreciation for teamwork has grown over the years. In high school and college, I thought I could do physics all by myself as an individual. Having a good teacher was prerequisite, of course, and even taken for granted. During graduate school, this individuality started giving way as I worked closely with another generous graduate student. As a postdoc, I found that individuality would really break down, and I succeeded only because I was part of a positive environment where each postdoc was really helping the other to succeed. Now I work at Raith.

Nanoscale problems are just too hard to solve without cooperation between smart and positive people. Teamwork therefore underlies the significant advances in nanoscale science and engineering. Much like the teamwork between students, postdocs, professors, universities, and technology companies, there is the cooperation between Raith and our customers. Raith is committed to enabling the success of our customers, who are advancing quantum physics and computing, photonics, plasmonics, biotechnology, nanoelectronics, 1D and 2D nanomaterials and systems, compound semiconductors, superconducting devices, nanofabrication, x-ray microscopy, electron/ion microscopy, metrology, maskless ion implantation, ion-solid interactions, communications, energy, security and cybersecurity, reverse engineering, and neuroscience.

The essence of Raith’s contribution towards advancing these fields is to place complex patterns of charged particles at resolutions and accuracies down to the order 100 nanometer over areas spanning 108 nanometers, and do so after the instrument has shipped over a distance of the order 1015 nanometers. As part of its mission in supporting the advances in nanoscale science and engineering, Raith associates can make these instruments perform to their fullest potential, have a practical understanding of e.g. how thermal expansion coefficients and imperfections in charged particle optical systems can wreak havoc at the nanoscale, and how the same technology that was recently used to detect gravitational waves is practically employed for ultra-accurate sample motion. Raith is an excellent alternative to a career in academia because we have a similar mission.

Thursday May 23, 2019 during common hour

Please note the change in location. This will be in Olin 115.

Biomechanical Insights Into Flexible Wings From Gliding Mammals

Gregory Byrnes

Biology Department, Siena College

Gliding evolved at least nine times in mammals. Despite the abundance and diversity of gliding mammals, little is known about their convergent morphology and mechanisms of aerodynamic control. Many gliding animals are capable of impressive and agile aerial behaviors and their flight performance depends on the aerodynamic forces resulting from airflow interacting with a flexible, membranous wing (patagium). Although the mechanisms that gliders use to control dynamic flight are poorly understood, the shape of the gliding membrane (e.g., angle of attack, camber) is likely a primary factor governing the control of the interaction between aerodynamic forces and the animal’s body. Data from field studies of gliding behavior, lab experiments examining membrane shape changes during glides and morphological and materials testing data of gliding membranes will be presented that can aid our understanding of the mechanisms gliding mammals use to control their membranous wings and potentially provide insights into the design of man-made flexible wings.

Thursday May 30, 2019 during common hour in S&E N304

Fast Neutron Resonance Radiography for Elemental Imaging

David Russell Perticone
MIT

We present experimental evidence supporting the technique of Fast Neutron Resonance Radiography (NRR). A set of neutron attenuation images collected at several different neutron energies are transformed into a set of elemental maps, indicating the presence and quantity of a fixed set of basis elements. Here we report on the construction, calibration, and results from a prototype NRR imaging system. We discuss the utility of elemental maps for automated detection of materials as well as standoff non-destructive classification of chemical compounds. The initial application is explosive detection in air cargo containers.

Thursday June 6, 2019

Sigma Pi Sigma Induction: No seminar

Colloquium Schedule

Thursday January 10, 2019

Research Opportunities for Students.

Jef Wagner
Department of Physics and Astronomy, Union College

This is an information session. Prof. Wagner will discuss REU opportunities at the Department and outside the department. Members of the department will share their research and announce research opportunities in their team. Notes of the presentation are available through this link.

Thursday January 24, 2019

Life After Physics

Brandon Bartell ’10 (Union College)

Beyond academia and applied sciences in industry, career options for physicists are varied and non-formulaic. This presentation follows the journey and decision-making of an aspiring academic physicist turned business consultant turned data scientist. The audience should expect to leave with a foundational understanding of consulting as a business model and as a career, data science and its applications in industry, and how a background in physics can prepare individuals for an alternative career beyond the physical sciences.

Thursday January 31, 2019

Please note the change in location. This will be in Olin 115.

Geothermal Heating and Cooling Systems: The Foundation of Zero-Emission Buildings

John Ciovacco
President of Aztech Geothermal, LLC

Geothermal heating and cooling systems (also known as, ground source heat pump systems) will be a significant contributor to society’s conversion away from fossil fuels. Geothermal space conditioning systems heat and cool homes and institutions at extremely high efficiencies by leveraging the constant temperatures found underground. The session will explain how geothermal works, why many institutions are undergoing geothermal conversions to achieve carbon reduction goals, and why New York’s electric utilities are specifically promoting the expansion of geothermal technology.

Thursday February 7, 2019

Optical imaging of atomic wave functions with diffraction-breaking resolution

Yang Wang
Joint Quantum Institute,University of Maryland

Optical trapping and imaging of atoms plays an essential role in cold-atom physics, ranging from precision measurement to the study of correlated many body systems. Due to the diffraction limit, trapping and imaging are typically limited to length scales on the order of the wavelength of the light. The nonlinear response of three-level atoms, however, supports a dark state with spatial structures much smaller than the wavelength. In this talk, I will present the experimental use of such dark state spatial structure to probe the atomic wave function with a resolution of lambda/50 (lambda is the wavelength of the imaging light), far below the diffraction limit. The coherent nature of our approach also provides a fast temporal resolution (500 ns), with which we could observe the quantum motion of atoms “live” inside the unit cell of an optical lattice.
Reference:
[1] arXiv: 1807.02871
[2] PRL 120, 083601 (2018)

Thursday February 14, 2019

Cosmic Lego: Making molecules on stardust

Gianfranco Vidali
Physics Department, Syracuse University

Where did we come from? This question might not have an answer yet, but, as proposals for a non-terrestrial origin of life have gained some traction, astrophysicists and astrochemists have begun to ask whether there are molecules in space that are complex enough to be used as building blocks of life.
I always like to show how we learn about the physical world based on observations, experimentation and deduction. In this presentation, I’ll give a brief survey of space environments where molecules have been found and show that key molecules for origin of life do form, and they do on stardust. Then I’ll show how observations, laboratory work and computer simulations can be used to uncover the physical and chemical processes of molecule formation in space, and how they can help guide observations.

Thursday February 28, 2019

INNOVATION, INTELLECTUAL PROPERTY & ENTREPRENEURSHIP LAW

Shahrokh Falati, Ph.D., J.D.
Director of Programs for Intellectual Property, Tech. Transfer, Innovation & Entrepreneurship Law, Albany Law School

Bio: Shahrokh (Seve) Falati’s area of legal expertise includes Patent Law; Trademark & Unfair Competition Law; Intellectual Property Law; and the interdisciplinary legal fields governing legal representation of entrepreneurs and innovators (aka Entrepreneurship Law). Prof. Falati is the Director of Programs for Intellectual Property, Technology Transfer & Entrepreneurship Law at Albany Law School. Prior to joining the faculty at Albany Law School, for over a decade, Professor Falati worked in private practice, focusing exclusively on representing clients on Intellectual Property Law and related legal matters at two large prominent law firms in New York (Jones Day, and HRFM). He maintains a small private practice. He is admitted to practice law in New York and Massachusetts, before the United States District Court for the District of Massachusetts, and as a registered patent attorney before the United States Patent & Trademark Office.

Thursday March 14, 2019

Revealing Light-Matter Interactions at the Nanoscale using Single-Molecule Super-Resolution Microscopy

Esther A. Wertz
Department of Physics, Applied Physics & Astronomy, RPI

Metal nanoparticles (NPs) sustain a collective oscillation of their free electrons, called a localized surface plasmon resonance (LSPR), when excited by an electromagnetic wave. When this incident wave is resonant with the LSPR frequency, the field intensity is strongly increased in the near field of the NP. Plasmonics thus provides a unique tool for the manipulation and confinement of light well beyond the diffraction limit. This has opened up a wide range of applications based on extreme light concentration, including nanophotonic lasers and amplifiers, optical metamaterials, biochemical sensing, and antennas transmitting and receiving light signals at the nanoscale. However, many difficulties remain in experimentally measuring the shape, size, and enhanced field properties of the localized electromagnetic modes in the vicinity of the NPs due to the limitations of optical microscopy. In this seminar, I will discuss how we can unravel the coupling of light to a nano - antenna through single - molecule fluorescence imaging. This technique is a powerful tool to optically study structures beyond the diffraction limit by localizing isolated fluorophores and fitting the emission profile to the microscope point-spread function. By using the random motion of single dye molecules in solution to stochastically scan the surface, and by assessing emission intensity, wavelength, and density of emitters as a function of position, we gain new insight into the properties of these systems and pave the way for the development of better plasmonic devices.

Colloquium Schedule

Thursday September 06, 2018

1st week of classes: no seminar

Thursday September 13, 2018 during common hour in S&E N304

Student Poster Presentation

Department of Physics and Astronomy, Union College

The department hallways will be decorated by posters by Union College physics majors who participated in summer research this year. The authors will stand by their posters to discuss their work and answer our questions while we all enjoy lunch during our first official colloquium of the new academic year.

Thursday September 20, 2018 during common hour in S&E N304

The Physics of the Exposure of Photoresists to Extreme Ultraviolet (EUV, 13.5 nm) Light

Robert L. Brainard
Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute

For the past fifty years, the microelectronics industry has been on a relentless pace to improve the performance of integrated circuits by fabricating more transistors onto every chip. One key technology which has made these dramatic improvements possible has been photoresists (Figure 1A). Central to improving the resolution capability of photoresists has been the successive reduction in the wavelength of light used to expose them. Currently, the microelectronics industry is undergoing a jump in wavelength from 193 to 13.5 nm. This new wavelength is called Extreme Ultraviolet (EUV)) light. This large change in wavelength comes with a concomitant change in photon energy (6.4 to 92 eV) which creates several interesting problems for chemists and physicists to solve. This presentation will start with a broad introduction to photoresists and EUV lithography. It then will describe how 92 eV EUV photons ionize molecules in resists, creating holes and free electrons, and identify and discuss the individual interactions that occur with atoms (Figure 1B). However, the number of electrons created, their reaction mechanisms, their lifetimes and their reaction cross-sections are not well known. The presentation will discuss experimental results and provide insight into these poorly understood aspects of EUV exposure mechanisms (Figure 1C). Lastly, the presentation will discuss the challenges associated with the low numbers of high-energy photons that are available during exposure relative to the longer wavelength 193-nm lithography that proceeded EUV. These low numbers of photons create statistical-noise problems described as shot-noise and related to Poisson statistics. These statistics ultimately place a limit to the ultimate resolution, line-roughness, and sensitivity of this imaging technology.

Joint Seminar with Chemistry and Mechanical Engineering

Thursday October 4, 2018 during common hour: Location Olin 115

X-ray Optics Development at NASA Marshall Space Flight Center

David Broadway
Research Physicist, NASA MSFC, Huntsville, AL

The path toward the development of X-ray optics for the next generation of high resolution, large collecting area space-borne telescopes is discussed. A leading technological challenge associated with this development is due to the intrinsic stress in the nanometer-scale thin film coatings that are deposited to enhance the reflective performance of the optics. The coating stress causes severe distortion of the thin (~400 µm), precisely figured substrates and degrades the imaging resolution of the optics. Therefore, a novel optical method for the in-situ measurement of thin film stress has been developed to help identify process mechanisms for reducing or eliminating film stress. The device utilizes a fiber optic displacement sensor (FODS) to measure the evolving substrate curvature during the deposition process. The measured substrate curvature is proportional to the integrated film stress as described by the Stoney equation. The minimum detectable integrated stress of the device is presented and compared to other state-of-the-art optical methods of in-situ stress measurement. The reproducibility and sensitivity of the apparatus is demonstrated through stress measurements of tungsten (W) and amorphous silicon (Si) single and multilayer thin-films deposited on 100µm thick Schott D263 glass substrates by the process of magnetron sputtering. Additionally the use of silica aerogels produced by Union College’s rapid supercritical extraction technique as a potential method for replicating unprecedented ultra-lightweight mirrors from precision optical quality molds is discussed.

Thursday October 11, 2018 during common hour in S&E N304

The Physics of Wetting and Spreading at the Nanoscale

Mesfin Tsige
Department of Polymer Science, University of Akron, Akron, Ohio, USA

There is a tremendous need for a greater understanding of the properties of matter at the nanometer scale mainly driven by the unprecedented impact of nanoscale materials in current industrial products. It is well known that matter behaves in complex ways and exhibits exotic properties at nanometer length scales. However, understanding the behavior of matter at such length scales using experimental methods has in general been very difficult. Computer simulations have proven very useful in predicting properties of novel materials yet to be synthesized as well as predicting difficult to measure or poorly understood properties of existing materials. The most commonly used computational technique for investigating structural and dynamical properties of nanoscale materials is molecular dynamics simulations. I will discuss the physics embedded in this computational tool and its use for simulating soft materials behavior at the atomic scale. Specifically, I will talk about my group’s current effort in quantifying the dynamics of hydrogen bonding and its effect on the spreading behavior of nanoscale water droplets on polymer surfaces using molecular dynamics simulations. Hydrogen bonding is very critical to a wide range of systems, from the existence of liquid water at room temperature to the structure of DNA (double helix) and many other biomolecules. Understanding the strength and dynamics of hydrogen bonds has stimulated a large and growing body of experimental and theoretical work. However, despite much research progress made over the years on this topic, our understanding of the dynamics of hydrogen bonds, especially at surfaces and interfaces, is still work in progress.

Thursday October 18, 2018 during common hour in S&E N304

Lattices, Supersymmetry and Strings

Joel Giedt
Department of Physics, Applied Physics & Astronomy, RPI

In this talk I will explain why lattice discretizations of spacetime can help us to study challenging theories like supersymmetric gauge theories numerically. Some aspects of the high-end computing platforms that we use will also be discussed. Questions about quantum gravity and remarkable dualities can be addressed using techniques that were first developed to study the strong nuclear interaction. I will finish the talk by describing how string compactifications may be used to describe models of dark matter that is self-interacting, and may also provide tools to understand interactions with the Standard Model.

Thursday November 1, 2018 during common hour in S&E N304

Liquid-liquid phase separation in concentrated protein mixtures, with application to cataract

George Thurston
School of Physics and Astronomy, RIT

Liquid-liquid phase separation, the solution analogue of the liquid-vapor transition, has long been demonstrated to occur in aqueous solutions and in membranes of biological molecules. Recently, there has been a rapid pace of discoveries of liquid-liquid phase separation that are important in physiology and disease. We will introduce liquid-liquid phase separation for a general audience, and will describe our own studies of its occurrence in concentrated aqueous mixtures of eye lens proteins, which are important in cataract disease. We will then describe our ongoing studies of how charge regulation affects liquid­-liquid phase separation of the eye lens protein gamma crystallin. For gamma crystallin, our grand­-canonical distribution model indicates that hundreds of coexisting, equilibrium charging patterns have enough probability to affect protein interactions. We describe a theoretical framework for studying the resulting, simultaneous liquid-liquid phase separation and multiple chemical equilibrium, which resembles the situation that occurs in micellar and microemulsion solutions. Supported by NIH R15EY018249.

Thursday November 8, 2018 during common hour in S&E N304

Research Opportunities for Students.

Jef Wagner
Department of Physics and Astronomy, Union College

This is an information session. Prof. Wagner will discuss REU opportunities at the Department and outside the department. Members of the department will share their research and announce research opportunities in their team. Notes of the presentation are available through this link.

Thursday April 5, 2018

1st week of classes: no seminar

Thursday April 12, 2018 during common hour in S&E N304

The Fate of Exploding White Dwarfs

Robert Fisher
Department of Physics, University of Massachusetts Dartmouth

Type Ia supernovae play an important role as standardizable candles for cosmology, providing one of the most important probes into the nature of dark energy. Yet, the nature of the stellar progenitors which give rise to Type Ia supernovae remains elusive. For decades, the leading model explaining Type Ia supernovae properties consisted of a white dwarf accreting to near the Chandrasekhar mass, in the single-degenerate channel. More recently, a variety of lines of evidence point instead towards merging binary white dwarfs in the double-degenerate channel as the progenitors of most Type Ia supernovae. In this talk, I will focus upon recent advances at the interface between observation and theory which will help crack the Type Ia progenitor problem.

Thursday April 19, 2018

No Seminar

Thursday April 26, 2018 during common hour in S&E N304

A Gamified Approach to Online Astronomy Education

Danny Barringer
Union College ‘11, M.S./M.Ed. Penn State

Online education is the way of the future! Or so we keep hearing. As schools race to increase their online course offerings, scholarship on innovative ways to use this new educational space is relatively lacking. I will be talking about the state of the online education field broadly, including an overview of the role that games can fill in educational settings. I present on some work I've done evaluating student performance in an online, gamified version of introductory astronomy taught at Penn State since 2014, and how the most gamified aspects contribute (or not) to student learning. I close with my own thoughts about how we can most effectively use these new educational platforms and what challenges still need to be properly addressed.

Thursday May 3, 2018 during common hour in S&E N304

Why Physics?

Hal Tugal
BS Physics Union College ’71, MS Physics UNH ’73; PhD Engineering UNH ’77

After spending childhood in Europe and growing up in NY (Brooklyn, NY, then Ardsley, NY in Westchester Country), Hal Tugal realized that no matter how much he liked arts, he was better suited for physics. He attended Union College in Schenectady, NY, went to the University of New Hampshire to earn MS in physics (Space Science), and finally a PhD in Theoretical and Applied Mechanics in the Mechanical Engineering Department. He spent over 30 years in industry applying classical physics to solve problems in the power, metal and glass containers, defense, aerospace and semiconductor industries. His brief talk today will be on, Why physics?

Thursday May 10, 2018

Steinmetz week: No seminar

Thursday May 17, 2018 during common hour in S&E N304

A Modeling Study of Low-Level-Jets over the Mid-Atlantic Region

Mengsteab H. Weldegaber
Department of Physics & Astronomy, Howard University

A modeling study of the Low-Level-Jets over the mid-Atlantic region is presented. The Low-Level-Jets were observed during the Water Vapor Validation Experiments (WAVES), a NASA Satellite validation experiment, at Howard University Beltsville research Campus in summer 2006/07. The objective of this research is to understand the dynamics and the strength the winds during the observed Low-Level-Jets over Baltimore-Washington area; and also to test and evaluate the Weather Research and Forecasting (WRF) model. The observed high-resolution wind profiles from Maryland Department of Environment; radio soundings and lidar observations at Beltsville; and lidar observations at University of Maryland Baltimore County are used to validate the simulated wind and moisture profiles. Sensitivity simulations using different boundary layer schemes in WRF model with the Advanced Research WRF (ARW) dynamic core will be discussed.

Thursday May 24, 2018 during common hour in S&E N304

Determining Stellar Properties using Asteroseismology

Lucas Viani ‘14
Yale Center for Astronomy and Astrophysics, Yale University

Asteroseismology, the study of stars using stellar oscillations and pulsations, allows astronomers to derive stellar properties such as mass, radius, and age more accurately and precisely than ever before. Additionally, unlike with isochrone fitting, stellar properties can be determined without the need for distance or extinction estimates. The basic asteroseismic parameters provide valuable information about a star’s interior and can be determined even in poor signal-to-noise observations, making them readily available for a large number of stars. Here we show how asteroseismology can be used to determine stellar properties and examine the accuracy and pitfalls of such methods. Additionally, we use Kepler data to improve how convection is modeled in star.

Thursday May 31, 2018 during common hour in S&E N304

The Modern Alchemy of Converting Office Supplies into Smart Materials

Kevin Cavicchi
Department of Polymer Engineering, University of Akron

Shape-morphing materials are one class of smart materials that adjust their shape in response to an external stimuli. These materials find application as sensors and for remote manipulation of materials in industries ranging from aerospace to biomedical to consumer products. This talk will discuss two types of shape morphing polymers: shape memory polymers (SMPs) and actuators. In an SMP a range of elastic deformation is temporarily locked into place through a programming sequence of heating, deformation, and cooling and triggered to return to its initial shape upon the application of an external stimulus. Actuators, on the other hand are able to oscillate between two shapes in response to an environmental trigger (e.g. heat, humidity). This talk will describe facile methods to fabricate these materials by blending commercial elastomers and waxes. This compounding approach allows each component to synergistically contribute separate functions to the shape morphing materials, which simplifies the design of the individual components and opens up the ability to fine-tune the shape morphing properties through the blend formulation. Two examples will be presented where first, the wax forms a solid networks to gel the surrounding elastomer and fix elastic deformation, and second, the melting and expansion of the wax dilates the surrounding elastomer to actuate the shape.

Thursday June 7, 2018

Sigma Pi Sigma Induction: No seminar

Thursday January 05, 2017

Summer research opportunities

we will provide information to students about research opportunities at Union and outside Union.

Thursday February 9, 2017 -- Moved to April 27 due to Weather

A Career in Big Data: Physics and the Software Industry

Jason Slaunwhite '04

During this talk I will share a few short stories from my career in Big Data. After graduating from Union in 2004, I did research in High Energy Particle Physics and went on work at the CERN laboratory in Switzerland. I have continued to work with Big Data as a software developer for an analytic database company. I hope that by sharing a few of my experiences with current physics majors, I can provide some perspective on the different opportunities that they may consider pursuing after graduation.

Thursday February 16, 2017

Synchronization in Networks of Biomimetic Artificial Neurons

Harold M Hastings
Division of Science, Bard College at Simon’s Rock, and Department of Physics and Astronomy, Hofstra University

There has been a long tradition of the study of model neurons, beginning with pioneering work of Hodgkin and Huxley. Subsequently FitzHugh, Nagumo and colleagues developed a simplified two variable conductance model for neuronal dynamics, consisting membrane potential whose (fast) dynamics reflect a non-linear sodium current and a (slow) gate variable (potassium current). FitzHugh-Nagumo neurons can display either excitable (sufficiently large stimuli generate action potentials before returning to steady state) or oscillatory dynamics, depending upon parameter values. We explore the dynamics networks of FitzHugh-Nagumo neurons and analogues, especially Keener’s modification of the original Nagumo circuit and the Belousov - Zhabotinsky chemical reaction, the prototype chemical oscillatory system. A wide variety of complex synchronization and emergent behavior is seen. There are potential applications to computer science, biology, and biomedicine.

Selected References:

• Alford, S.T., Alpert, M.H., A synaptic mechanism for network synchrony. Frontiers Cellular Neuroscience 8, doi.org/10.3389/fncel.2014.00290 (2014)
• Arumugam, E.M.E., Spano, M.L., A chimeric path to neuronal synchronization. Chaos 25, 013107 (2015)
• Belair, J., et al., Dynamical disease: identification, temporal aspects and treatment strategies of human illness. Chaos 5, 1 (1995)
• Beuter, A., Bélair, J., Labrie, C., Feedback and delays in neurological diseases: a modeling study using dynamical systems. Bull. Math. Biol. 55, 525 (1993).
• FitzHugh, R., Impulses and physiological states in theoretical models of nerve membrane. Biophys. J. 1, 445 (1961).
• Hastings, H.M., Field, R.J., Sobel, S.G., Microscopic fluctuations and pattern formation in a supercritical oscillatory chemical system. The Journal of chemical physics, 119, 3291 (2003).
• Hastings, H.M., et al., Bromide control, bifurcation and activation in the Belousov − Zhabotinsky Reaction. J. Phys. Chem. A 112, 4715-4718 (2008).
• Hastings, H.M. et al., Oregonator Scaling Motivated by Showalter-Noyes Limit. J. Phys. Chem. A 120, 8006 (2016).
• Hastings, H.M. et al., Dynamics of Biomimetic Electronic Artificial Neural Networks, Proceedings of the 4th International Conference on Applications in Nonlinear Dynamics (ICAND 2016), Ed: V. In, P. Longhini, A. Palacios, Springer (in press, to appear in 2017).
• Keener, J.P., Analog circuitry for the van der Pol and FitzHugh-Nagumo equations. IEEE Trans. Systems Man Cybernetics 5, 1010 (1983).
• Nagumo, J., Arimoto, S., Yoshizawa, S., An active pulse transmission line simulating nerve axon. Proc. IRE 50, 2061 (1962).
• Tompkins, N., et al., Creation and perturbation of planar networks of chemical oscillators. Chaos 25, 064611 (2015).
• Tuma, T., et al., Stochastic phase-change neurons. Nature Nanotech. 11, 693 2016).

Thursday February 23, 2017

Founders Day

Thursday March 2, 2017

Craig Luckfield
PASCO scientific

Thursday March 9, 2017

Synthesis of Device-Quality Graphene Films

Carl A. Ventrice, Jr.
Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY

Graphene is a single atomic layer of carbon that is crystallized in the honeycomb configuration. It has many unique properties that are of particular interest for the development of nanoscale electronic devices and sensors. In particular, it is a semi-metal whose charge carrier density can be continuously tuned from n-type to p-type by applying an external electric field and has a linear energy-momentum dispersion in the vicinity of the Dirac point, which results in carrier mobilities that are higher than almost all semiconductors. It also has a very large in-plane thermal conductivity and exceptional mechanical properties. However, one of the primary issues that must be addressed before nanoscale electronic devices and sensors can be routinely fabricated is the development of methods for growing large-scale, device-quality, graphene films with uniform thickness at a relatively low cost. An overview will be given of the techniques currently used for graphene synthesis and the research being done in my laboratory to synthesize single crystal films of graphene.

Thursday September 07, 2017
1st week of classes: no talk scheduled

Thursday September 14, 2017

Effects of Supplementary Information on Solution Methods to Kinematics Problems

Evan Halstead
Physics Department, Skidmore College

A student once told me that the formula sheets I provided for tests always made her want to immediately jump to the formula sheet for every problem instead of thinking about it first. That got me wondering whether I was inadvertently influencing all of my students' solution methods with subtle cues. To answer this question, a team of students and I devised an experiment in which participants solved three kinematics questions while having access to either relevant equations, irrelevant equations, an image, or no supplementary information at all. They were then asked to describe their solution process. Answers were grouped by solution method in order to see if the type of supplementary information that was provided correlated with the solution method. I present and comment on the results.

Thursday September 21, 2017

Summer Student Poster Day

The department hallways will be decorated by posters by Union College physics majors who participated in summer research this year. The authors will stand by their posters to discuss their work and answer our questions while we all enjoy lunch during our first official colloquium of the new academic year.

Thursday September 28, 2017

Signal Processing Using Chaos

Chandra Pappu
Electrical, Computer and Biomedical Engineering, Union College

A new, rich class of oscillators namely chaotic oscillators with nonlinear behavior have tremendous potentials in the field of signal processing. Due to its self-synchronizing capabilities these oscillators can be used in network synchronization, receiver-transmitter synchronization etc. In addition, chaotic waveforms generated by chaotic systems are noise like and wideband in nature. The potentials of these chaotic systems are illustrated considering few examples. Firstly, I illustrate the application of chaos for secret communications. Secondly, I show the advantages of using chaotic frequency modulated signals in jamming/interference environment. Finally, I demonstrate the high resolution capability of chaotic waveform considering BOEING 777 airplane.

Please note the change in location. This seminar will be in Lippman 017.

Thursday October 05, 2017

A Classical, Magnetic, Many-Body System
or
Adventures in Desk Toy Physics

Nelia Mann
Department of Physics & Astronomy, Union College

®Buckyballs are small, strong, spherical magnets sold in sets as popular desk toys. Each separate magnet can be well modeled as a magnetic dipole, and thus interactions between pairs of magnets are easily understood in terms of classical electrodynamics. In larger numbers, the magnets form structures that can be thought of as analogous to structures of atoms or molecules within bulk materials. In this talk, I will utilize some of the traditional tools of solid state physics along with numerical techniques to analyze this “toy system”. The results suggest that insight into real solid state systems might be gained through comparison to this system.

Thursday October 12, 2017

Superconducting qubits for quantum processors

Daniela Bogorin
National Research Council Fellow, Air Force Research Laboratory

In the last two decades remarkable advances have been made in quantum information processing. There are many technologies that are being developed for the physical realization of a quantum bit (qubit), each with its own advantages and disadvantages. These technologies include optical photons, trapped ions, superconducting qubits, neutral atoms, molecules, quantum dots, nuclear spins, and NV centers in diamond among others. Superconducting qubits based on Josephson Junctions superconducting circuits is one of the leading technologies. Progress in the development of superconducting qubits in the last five years demonstrates a viable path towards quantum processors with tens of qubits, required for proving quantum supremacy and ultimately towards a fault tolerant quantum computer. Superconducting qubits have high coherences ~ 100 μs and are manipulated by fast gates ~ few ns and are fabricated using semiconductor technology. In this talk I will present a short overview of the field and an introduction of superconducting qubit technology.

Thursday October 19, 2017

Confining colloids: From dynamic artificial cells to luminescent nanodiamond sensors

Viva Horowitz
Department of Physics, Hamilton College

Watching nano- and microscale particles in confined environments can reveal new physics, whether we create a dynamic system that mimics cellular motion or use the quantum spin of nanodiamonds to explore a magnetic environment. In the first part of this talk, we’ll explore the possibilities of using self-propelled particles to create a super-diffusive system that beats Brownian motion, much like the interior of cells. We’ll discuss how to investigate the motion of these particles using holography and other optical techniques, and see how these particles can be encapsulated in lipid vesicles or in droplets. The dynamics and transport processes of this artificial cytoplasm may prove necessary to sustain gene expression, growth, and reproduction in future artificial cells. In the second part, we’ll explore how nitrogen-vacancy color centers embedded in nanoparticle diamonds have electronic quantum spin states that are sensitive to magnetic fields via electron spin resonance. When we pick up these nanodiamond probes using optical tweezers, we can measure and map the magnetic environment despite the motion and random orientation of nanodiamonds levitated by the laser beam. However, challenges remain: these spin states are sensitive to impurities in the diamond crystal and surroundings. We need to find the best diamond particles for spin-based magnetic, electric, and thermal sensing in fluidic environments and biophysical systems. Toward this end, we are building a microfluidic device to sort nanodiamonds according to their optical properties.

Please note the change in location. This seminar will be in N300.

Thursday October 26, 2017

Nucleation in Undercooled Metal Droplets –Applications in the Microelectronics Industry

Eric Cotts
Physics and Materials Science, Binghamton University

Most of the metallic materials that we use in daily life are prepared by casting from the melt. We seek to understand and control the physics of such solidification processes. Classical nucleation theory reflects the essence of the nucleation and initial growth of crystals from an undercooled melt. It works best for systems with simpler bonding mechanisms, such as Lennard-Jones and many transition metals. For more complex systems, such as Sn, metastable precursors form first from the melt at nanometer length scales. These metastable inoculants can affect the entire structure of solids, and their properties (for instance in microelectronic interconnects). We explore the nucleation of undercooled Sn droplets as a function of impurity concentration, and examine effects on the microstructure, and properties, of interconnects in electronic packages.

Thursday November 02, 2017

Physics in Radiation Oncology

Tom Mazur (class of 2007)

Applications of physics pervade medicine. “Medical Physics” refers to careers in radiology and radiation oncology that provide support for the safe and effective delivery of radiation to cancer patients for both diagnostics and therapy. A conventional career trajectory for a medical physicist begins with a post-graduate degree in Medical Physics that covers a specialized curriculum tailored to a career in a clinical setting. Many clinics, especially in academic settings, increasingly value candidates with non-conventional backgrounds in basic sciences like physics. After graduating from Union College, I attended graduate school in the physics department at The University of Texas at Austin where I studied atomic physics. After graduate school, I was a post-doctoral researcher in the radiation oncology department at the Washington University School of Medicine in St. Louis. I now am a researcher and clinical trainee in the same department. In this talk I will describe careers in medical physics, including necessary pre-requisites and training, day-to-day responsibilities, various technologies, and opportunities for research.

Thursday November 09, 2017 No: seminar

The Department is hosting the NYSSAPS and ASNY joint Fall meeting on Gravitational Waves on November 10 and 11. For more information and registration, visit www.nyssaps.org.

Congratulations Prof Rainer Weiss on Winning the 2017 Nobel Prize in Physics!

Thursday March 30, 2017

Fractals and the Drip Paintings of Jackson Pollock

Katherine Brown (Jones-Smith)
Physics Department, Hamilton College

In the late 1990s, a group of physicists analyzed some of the most famous drip paintings by the celebrated Abstract Expressionist painter Jackson Pollock. Assuming Pollock underwent a particular type of chaotic motion, they found that every layer of every painting they analyzed possessed the same fractal characteristics. From this they conjectured that Pollock was able to create a unique fractal 'signature' in his work, and that fractal analysis could therefore be used as an authentication tool in paintings of disputed origin. It turns out that this hypothesis of 'Fractal Expressionism' is flawed in several important ways. I will present an account of the techniques used in fractal analysis and the pitfalls which ensue from applying them to Pollock's drip paintings. I will also discuss several new findings from the realm of fractal mathematics which were motivated by this work.

Thursday April 6, 2017

Excitons in Small Molecules Crystalline Thin Films

Madalina Furis
Physics Department, University of Vermont

Organic electronics, an interdisciplinary research area traditionally more connected to organic synthetic chemistry and polymer science than condensed matter physics, is currently undergoing a major transformation. The advent of high mobility small molecule semiconductors and new avenues for scalable thin film and device fabrication introduce a new paradigm in the way we think about the future of electronics.

At the University of Vermont my research group focuses on exploring crystalline organic semiconducting thin films using condensed matter experimental approaches (such as low temperature, polarization-resolved, ultrafast spectroscopy) on a quest for signatures of many-body physics in these systems. Recent results include: i) the observation of a low temperature coherent exciton state [1] ii) the surprising discovery of excitonic states localized at the grain boundary that may provide new insight on exciton diffusion in these systems,[2]

1. Rawat, N., et al. J.Phys. Chem. Lett. 2015, 6(10), 1834-1840.
2. Pan, Z., et al. Nat.Commun. 2015, 6.

Email Contact: Madalina.Furis@uvm.edu

Thursday April 13, 2017

Topology of the Universe: Hearing the Shape of a drum

Eric Greenwood
Geology and Physics Department, University of Southern Indiana

Observationally, we know that the universe is locally flat. This does not tell us, however, the overall shape of the universe; that is, it does not tell us anything about the global shape of the universe (topology). There are many different global shapes which yield the same local shape. The question of the structure and size of the universe is both an intellectually interesting and an important question in modern cosmology since the answer to these questions could give us insight into the ultimate fate of our universe. Additionally, knowledge of the shape and size of the universe will give us information about the metric of the universe, which has many implications such as implications toward quantum gravity. In this talk, we will investigate how to reconstruct the topology of the universe using the spectrum of eigen modes dictated by a particular topology; that is, we will investigate how to "hear the shape of a drum."

Thursday April 20, 2017

The God Quasiparticle: the Plasmon and Protein Spectroscopy

Shyamsunder Erramilli
Department of Physics, Boston University

How do we get an infrared vibrational spectrum of a protein molecule at attomole concentrations at room temperature? The absorption cross-section of the molecule is ~ 10-21 cm2, about 6 orders of magnitude smaller than methods based on fluorescent labels. To enhance the probability of absorption, we can exploit the very first quantum quasi-particle that was ever discovered, the plasmon. Nanoantenna can be used to enhance selected vibrational bands. Recently a collaboration with Dal Negro has used fractal structures for enhancing multiple infrared absorption band in the mid-infrared “fingerprint” region. The interaction between the phonon in the protein and the plasmon leads to extraordinary new phenomena. Plasmon-enhanced infrared spectroscopy has the potential to study changes in protein conformation without using labels, with discoveries of great interest to the Biological Physics community as well as the Biomedical community.

Thursday April 27, 2017

A Career in Big Data: Physics and the Software Industry

Jason Slaunwhite '04

During this talk I will share a few short stories from my career in Big Data. After graduating from Union in 2004, I did research in High Energy Particle Physics and went on work at the CERN laboratory in Switzerland. I have continued to work with Big Data as a software developer for an analytic database company. I hope that by sharing a few of my experiences with current physics majors, I can provide some perspective on the different opportunities that they may consider pursuing after graduation.

Thursday May 4, 2017

Thursday May 11, 2017

Steinmetz Symposium Week

Thursday May 18, 2017

Searching for the Sources of the Highest-Energy Cosmic Neutrinos

Colin Turley
Department of Physics, Penn State

We present two archival analyses attempting to identify gamma-ray counterparts to the public neutrino data from the IceCube neutrino observatory. Our first analysis is a targeted search for correlated neutrino and gamma-ray emission from six bright northern blazars. These blazars were subject to long-term monitoring campaigns by the VERITAS TeV gamma-ray observatory. We use the publicly-available VERITAS light-curves to identify periods of excess and flaring emission to serve as active temporal windows in a search for an excess of neutrinos, relative to Poisson fluctuations of the near-isotropic atmospheric neutrino background. Our second analysis searches for an excess of statistically significant coincidences between Ice-Cube neutrinos from the 40 and 59 string configurations and gamma-rays detected by the Fermi LAT satellite. Both analyses are examples of more general multi-messenger studies that the Astrophysical Multi-messenger Observatory Network (AMON) aims to perform. For both analyses, we present the component neutrino and gamma-ray datasets, the statistical approaches, the results of the analyses, and future extensions to these studies.

Thursday May 25, 2017

Optics and electronics in two-dimensional (2D) materials

Swastik Kar
Department of Physics, Northeastern University

In the past decade, atomically-thin, layered or 2D materials have generated enormous interest within the science and engineering community. The unique nature of charge carriers, often experiencing strong interactions within a 2D confinement has led to spectacular new physical observations. At the same time, remarkable new applications have been shown to be possible within these materials with atomically-thin form-factors. This talk will outline some of the recent developments in our research group in the synthesis of 2D materials and their heterostructures, characterizations of their novel optical and electronic properties, and development of applications in the nanoelectronics, optoelectronics, sensing, detection, actuation, energy, and other areas. The aim will be to motivate how the novel physics of quantum matter can be potentially harnessed to develop applications with unprecedented performances.

Thursday June 1, 2017

Sigma Pi Sigma Induction

Thursday January 05, 2017

Summer research opportunities

we will provide information to students about research opportunities at Union and outside Union.

Thursday February 9, 2017 -- Moved to April 27 due to Weather

A Career in Big Data: Physics and the Software Industry

Jason Slaunwhite '04

During this talk I will share a few short stories from my career in Big Data. After graduating from Union in 2004, I did research in High Energy Particle Physics and went on work at the CERN laboratory in Switzerland. I have continued to work with Big Data as a software developer for an analytic database company. I hope that by sharing a few of my experiences with current physics majors, I can provide some perspective on the different opportunities that they may consider pursuing after graduation.

Thursday February 16, 2017

Synchronization in Networks of Biomimetic Artificial Neurons

Harold M Hastings
Division of Science, Bard College at Simon’s Rock, and Department of Physics and Astronomy, Hofstra University

There has been a long tradition of the study of model neurons, beginning with pioneering work of Hodgkin and Huxley. Subsequently FitzHugh, Nagumo and colleagues developed a simplified two variable conductance model for neuronal dynamics, consisting membrane potential whose (fast) dynamics reflect a non-linear sodium current and a (slow) gate variable (potassium current). FitzHugh-Nagumo neurons can display either excitable (sufficiently large stimuli generate action potentials before returning to steady state) or oscillatory dynamics, depending upon parameter values. We explore the dynamics networks of FitzHugh-Nagumo neurons and analogues, especially Keener’s modification of the original Nagumo circuit and the Belousov - Zhabotinsky chemical reaction, the prototype chemical oscillatory system. A wide variety of complex synchronization and emergent behavior is seen. There are potential applications to computer science, biology, and biomedicine.

Selected References:

• Alford, S.T., Alpert, M.H., A synaptic mechanism for network synchrony. Frontiers Cellular Neuroscience 8, doi.org/10.3389/fncel.2014.00290 (2014)
• Arumugam, E.M.E., Spano, M.L., A chimeric path to neuronal synchronization. Chaos 25, 013107 (2015)
• Belair, J., et al., Dynamical disease: identification, temporal aspects and treatment strategies of human illness. Chaos 5, 1 (1995)
• Beuter, A., Bélair, J., Labrie, C., Feedback and delays in neurological diseases: a modeling study using dynamical systems. Bull. Math. Biol. 55, 525 (1993).
• FitzHugh, R., Impulses and physiological states in theoretical models of nerve membrane. Biophys. J. 1, 445 (1961).
• Hastings, H.M., Field, R.J., Sobel, S.G., Microscopic fluctuations and pattern formation in a supercritical oscillatory chemical system. The Journal of chemical physics, 119, 3291 (2003).
• Hastings, H.M., et al., Bromide control, bifurcation and activation in the Belousov − Zhabotinsky Reaction. J. Phys. Chem. A 112, 4715-4718 (2008).
• Hastings, H.M. et al., Oregonator Scaling Motivated by Showalter-Noyes Limit. J. Phys. Chem. A 120, 8006 (2016).
• Hastings, H.M. et al., Dynamics of Biomimetic Electronic Artificial Neural Networks, Proceedings of the 4th International Conference on Applications in Nonlinear Dynamics (ICAND 2016), Ed: V. In, P. Longhini, A. Palacios, Springer (in press, to appear in 2017).
• Keener, J.P., Analog circuitry for the van der Pol and FitzHugh-Nagumo equations. IEEE Trans. Systems Man Cybernetics 5, 1010 (1983).
• Nagumo, J., Arimoto, S., Yoshizawa, S., An active pulse transmission line simulating nerve axon. Proc. IRE 50, 2061 (1962).
• Tompkins, N., et al., Creation and perturbation of planar networks of chemical oscillators. Chaos 25, 064611 (2015).
• Tuma, T., et al., Stochastic phase-change neurons. Nature Nanotech. 11, 693 2016).

Thursday February 23, 2017

Founders Day

Thursday March 2, 2017

Craig Luckfield
PASCO scientific

Thursday March 9, 2017

Synthesis of Device-Quality Graphene Films

Carl A. Ventrice, Jr.
Colleges of Nanoscale Science and Engineering, SUNY Polytechnic Institute, Albany, NY

Graphene is a single atomic layer of carbon that is crystallized in the honeycomb configuration. It has many unique properties that are of particular interest for the development of nanoscale electronic devices and sensors. In particular, it is a semi-metal whose charge carrier density can be continuously tuned from n-type to p-type by applying an external electric field and has a linear energy-momentum dispersion in the vicinity of the Dirac point, which results in carrier mobilities that are higher than almost all semiconductors. It also has a very large in-plane thermal conductivity and exceptional mechanical properties. However, one of the primary issues that must be addressed before nanoscale electronic devices and sensors can be routinely fabricated is the development of methods for growing large-scale, device-quality, graphene films with uniform thickness at a relatively low cost. An overview will be given of the techniques currently used for graphene synthesis and the research being done in my laboratory to synthesize single crystal films of graphene.

Thursday September 08, 2016
1st week of classes : No talk scheduled

Thursday September 15, 2016

Summer Student Poster Day

The department hallways will be decorated by posters by Union College physics majors who participated in summer research this year. The authors will stand by their posters to discuss their work and answer our questions while we all enjoy lunch during our first official colloquium of the new academic year.

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Thursday September 22, 2016

Few-Layer Black Phosphorus: a Material with tunable properties

Vincent Meunier
Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute

Black phosphorus (or “phosphorene” at the monolayer limit) has attracted significant attention as an emerging 2D material due to its unique properties compared with well-studied graphene and transition metal dichalcogenides such as MoS2 and WSe2. In bulk form, this monoelemental layered structure is a highly anisotropic semiconductor with a bandgap of 0.3 eV which presents marked differences in optical and electronic properties depending on crystalline directions. In addition, black phosphorus possesses high carrier mobility, making it promising for applications in high frequency electronics. A large number of characterization studies have been performed to understand the intrinsic properties of BP. Here I will present a number of investigations where first-principles modeling was combined with scanning tunneling microscopy (STM), Raman spectroscopy, and transmission electron microscopy (TEM) to assist in the design of phosphorene-based devices.

Thursday September 29, 2016

Dark matter: All your questions answered...with more questions!

Matthew Bellis
Department of Physics and Astronomy, Siena College

Over the last 50+ years, we have definitively learned that the motions of galaxies and clusters and the curvature of light on cosmological scales cannot be explained solely by the gravitational attraction of the baryonic matter in the universe. The leading theory to explain this discrepancy proposes a particle that does not interact through the strong or electromagnetic interaction: dark matter. However, no definitive experimental evidence for this particle has been found. This talk will give an introductory overview of the experimental searches for dark matter with an emphasis on WIMP (Weakly Interacting Massive Particle) models.

Wednesday October 05, 2016

Amorphous Materials: From Two-Dimensional Glass to Bubble Rafts

Kristen M. Burson
Physics Department, Hamilton College

Glass is a pervasive material in daily life, from windows, to fiber optics, to kitchen ware. Due to the abundant utility of glass there is much interest in answering the question: “What is the atomic structure of glass?” For crystalline materials, diffraction techniques can be used to determine the atomic configuration. But glass evades definitive atomic structure determination with the same techniques because it is complex and amorphous. SiO2 in its amorphous form is commonly known as glass for every-day uses. In this talk I’ll discuss recent work to determine the atomic structure of glass using scanning probe microscopy. I’ll show atomic resolution images of bilayer silica (SiO2), a model for glass, and present an assessment of the structure of model glass under application relevant conditions. Finally, this talk will explore the similarities between glass and other amorphous networks with special emphasis on a comparison between millimeter-scale bubble raft network structures and the atomic-scale silica network structure.

Thursday October 13, 2016

Mechanics of Fibrous Materials

Catalin R. Picu
Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute

Many biological and man-made materials have a fiber network as their structural component. Examples from the living world include the cellular cytoskeleton and various types of connective tissue. Examples from the non-living world include paper, rubber, insulation and consumer products, such as baby diapers. In this presentation I will review the mechanical behavior of various materials of this type. Further, the relationship between the microstructure and the mechanical properties of the network will be outlined, with emphasis on identifying regimes in which large changes of the system scale behavior are triggered by small changes of the system parameters. The discussion will underline differences between the behavior of fibrous materials and that of continuum bodies.

Thursday October 20, 2016

Phyllosilicate Emission from Protoplanetary Disks – The Indirect Detection of Extrasolar Water

Melissa Morris
Physics Department, SUNY Cortland

Phyllosilicates are hydrous minerals formed by the interaction between rock and liquid water and are commonly found in meteorites originating in the asteroid belt. These products of aqueous alteration of primitive planetesimals are believed to be the source of the majority of Earth’s water. The spectrum of the zodiacal dust in our Solar System (thought to result from collisions of planetesimals and sublimation of comets) has been modeled with the inclusion of phyllosilicates. Collisions between planetesimals in extrasolar protoplanetary disks may also produce dust containing phyllosilicates, indicating the presence of liquid water. It has been demonstrated that the characteristic emission features of these hydrous minerals are detectable in the infrared using instruments on board the Spitzer Space Telescope. In this talk, I discuss the phyllosilicates commonly found in meteorites, and describe our simple 2-layer radiative transfer disk code used to produce model spectral energy distributions (SEDs) of disks. I discuss how archived data from the Spitzer Space Telescope can be used to compare model SEDs of protoplanetary disks to observations. In this manner, we can determine whether liquid water is indicated in these extrasolar systems, and therefore, the possibility for life.

Thursday October 27, 2016

Explorations in the Geometry of Thinking

Kurt Przybilla
The Molecularium Project, Rensselaer Polytechnic Institute

Model building inspired by the works of Buckmister Fuller, the visionary inventor of geodesic domes and namesake of "Bucky Balls", led to the accidental discovery and patenting of the world's first spinning tops with more than one axis of spin. Co-creator, writer and producer of the Molecularium Project at RPI, Kurt Przybilla, shares a fast-paced, fun story of tetrahedrons, toys and the primary structural systems of the Universe.

Thursday November 03, 2016

String Theory in the Age of Duality

Cindy Keeler
Neils Bohr Institute

After a brief review of string theory and its genesis as a “Theory of Everything”, we will discuss the nature and use of dualities in modern string theory and quantum gravity. Dualities provide two (often very different!) descriptions of the same physical system. We will study an example of duality in Maxwell's equations, and then explore how these dualities have led to broad applications of string-inspired physics, far beyond its initial high energy physics beginnings.

Thursday November 10, 2016

From Ultracold Plasmas to White Dwarf Stars

Thomas C. Killian
Department of Physics & Astronomy, Rice University, Houston, TX 77005

Some of the most extreme environments in the universe can be described as strongly coupled plasmas, which are characterized by an average Coulomb interaction energy between neighboring particles that exceeds the thermal kinetic energy. This is the case in dense laboratory and astrophysical plasmas, such as in inertial-confinement-fusion experiments, white dwarf stars, and gas-giant-planet interiors. Strong interactions limit our ability to model and understand these systems because they violate fundamental assumptions underlying the standard theoretical description of collision rates and transport coefficients. They also lead to spatial correlations and surprising equilibration dynamics. I will describe how we can study the physics of strongly coupled plasmas in a system created by photoionizing laser-cooled atoms [1]. This creates the coldest neutral plasmas in existence, with temperatures barely one degree above absolute zero. Strong coupling is obtained at relatively low density, which slows the dynamics and makes short-timescale processes (compared to the inverse collision rate) experimentally accessible. This combination of atomic and plasma physics opens a new direction in the study of “dense” plasmas, which has traditionally been the playground of astrophysics and large national facilities. In particular, I will describe recent experiments studying the breakdown of standard kinetic theory and the measurement of self-diffusion [2,3].

This work is supported by the National Science Foundation, Department of Energy, and the Air Force Office of Scientific Research.

[1] “Ultracold Neutral Plasmas,” T. C. Killian and S. L Rolston, Phys. Today 63, 46 (2010).
[2] “Velocity relaxation in a strongly coupled plasma,” G. Bannasch, J. Castro, P. McQuillen, T. Pohl and T. C. Killian, Phys. Rev. Lett. 109, 185008 (2012).
[3] “Experimental measurement of non-Markovian dynamics and self-diffusion in a strongly coupled plasma,” T. S. Strickler, T. K. Langin, P. McQuillen, J. Daligault, and T. C. Killian, arXiv.org/1512.02288 (2015).