News & Events

Friday, June 22, 2018

Sewage, Sewage, Everywhere: Land, Air, and Water Exchange of Sewage Bacteria in the Saw Kill Watershed

M. Elias Dueker, Assistant Professor of Environmental Science

The extra-enteric ecology of sewage-indicating bacteria presents complexities for their use in management of water resources. Once released into the environment, these indicators may persist in sediments, and participate in multidirectional microbial exchange among water, sediment, and air. This complicates sewage pollution detection in public waterways, particularly in shallow freshwater tributaries prone to sediment resuspension. To address these challenges, we compared bacterial communities in sediment, water, and air in a small tributary of the Hudson River, above and below a sewage outflow. Using both culture-based and culture-independent methods, we found that sewage-associated bacteria, including sewage indicators, were present in sediment, water, and air on this waterway. Microbial communities from these ecological compartments were distinct, with sediment samples harboring greater microbial diversity than overlying water. Microbial communities responded to precipitation events, with water and sediment samples increasing in similarity with increases in waterway turbidity. While sediment samples clearly harbored sewage-indicating bacteria, they maintained a lower diversity of sewage-associated bacteria when compared to overlying water, suggesting that sediments may selectively promote environmental persistence of sewage-indicating bacteria.
Time: 3:30 pm – 4:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Friday, June 29, 2018

Beyond the Diffraction Limit: Imaging and Writing 3D Polymer Nanostructures with Visible Light

Chaitanya K. Ullal, Rensselaer Polytechnic Institute

Recent developments in far-field microscopy have enabled imaging at nanoscale resolutions using visible light. The circumvention of the diffraction limit opens the benefits of optical microscopy to polymer systems at the relevant nanometer length scales. These benefits include the ability to non-destructively provide local, dynamic and three-dimensional structural information. Specific examples related to colloidal crystals and block copolymers that would be challenging to image with contemporary techniques are used to highlight the potential of subdiffraction far-field fluorescence microscopy for the polymer and nanosciences. Ongoing work on imaging of nanoscale variations in cross-link density of colloidal gels and the application of super-resolution optics to lithography will also be presented.

Chaitanya Ullal is an assistant professor in the Department of Materials Science and Engineering at the Rensselaer Polytechnic Institute. He got his PhD in materials science and engineering at MIT and did a postdoc in the lab of Stefan Hell, at the MPI-BPC in Germany. He is a recipient of the NSF CAREER Award and the ACS PRF New Investigator Award. His research interests are related to unconventional nanofabrication, optics and polymers. A current emphasis of the group is the use of optical microscopy with nanoscale resolution to image and pattern nanostructured polymers.
Time: 3:00 pm – 4:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Past Events

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    • 2016

      Senior Project Poster Session

      December 13
      Reem-Kayden Center

      Astrophysics Student Presentation

      December 9
      Hegeman 107

      Astrophysics Student Presentation

      December 9
      Hegeman 107

      Into the Heart of the Milky Way: A Multiwavelength View of Sgr A*

      December 9
      Hegeman 107

      Sagittarius A* is the closest example of a supermassive black hole (SMBH) buried within a dense, massive stellar cluster. Sgr A* is more than 100 times closer than any other SMBH, and our proximity allows us to detect emission from its accretion flow in the radio, submillimeter (submm), near infrared (NIR), and X-ray regimes. These rich multiwavelength, time-resolved data have the power to probe the physical processes that underlie rapid flares originating near the black hole's event horizon. During ambitious Chandra X-ray and VLA radio monitoring campaigns over the last several years, we have detected the brightest-ever X-ray flares from Sgr A*. However, despite years of observational and theoretical study, we do not have a complete, unique model to explain these high-energy flares, or their relationship to variability at other wavelengths. Viable models range from the tidal disruption of asteroids to gravitational lensing to magnetic reconnection, motivating observers to place tighter constraints on the timing and multiwavelength properties of these outbursts. X-ray flares may also help us relate Sgr A* to weakly accreting black holes across the mass spectrum. I will discuss the possible origins and continuing mysteries surrounding Sgr A*'s high-energy flares and give a brief update on the X-ray and radio view of the Sgr A*/G2 interaction.

      Senior Prospectus Talks

      December 2
      Hegeman 107

      12 p.m. - 1 p.m.
      Eleanor Turrell
      Loren Jackson
      “Plasma Striations in Vacuum Tubes”
      Nowell Stoddard
      "Modeling the Nonlinear Cochlear”

      3 p.m. - 4 p.m.
      Victoria Chayes
      “Kerr Black Holes and the Reflected Light Problem”
      Max Meynig
      “Complex Trajectories and Semiclassical Methods”

      Quantum Foundations and the Minimal Modal Interpretation


      November 18
      Hegeman 107

      The language of random variables makes possible a formal analogy between classical probability theory and quantum theory that better highlights their key similarities and differences. I'll use this formulation to clarify the underlying problems that have long obstructed the development of a satisfactory interpretation of quantum theory, suggest changes in how we teach students quantum theory, discuss important new requirements for future work on quantum foundations, provide a helpful classification scheme for the various prominent interpretations, and motivate a novel "minimal" modal interpretation. This new interpretation is minimal in the sense that its fundamental ingredients are only those that either have clear counterparts in classical physics or are familiar from the traditional formulation of quantum theory. The rules governing the underlying dynamics of this interpretation are based on a class of newly discovered quantum conditional probabilities whose detailed properties I will discuss in depth. I'll conclude with a summary of open questions and implications for issues of importance to the foundations of physics.

      "Perfect Descriptions of Invisible Objects"

      November 16
      Olin, Room 102

      A tacit ideal of many a natural philosopher has been to find a perfect description – a complete, accurate reckoning – of part or all of the physical world. This ideal has led many scientists to search for the fundamental objects that make up reality and the rules that govern them. However, a gradual evolution in the understanding of the rules of quantum mechanics has fostered a rethinking of what it means to perfectly describe something, what it means to be fundamental, and even what it means to be an object. In this talk, Professor Cadden-Zimansky will discuss some key points of this evolution and describe how experimental research into states of matter in different dimensions has helped to illuminate the quest for perfect descriptions.

      *Please join us for a reception prior to the event beginning at 6:30 p.m. in the Olin Atrium

      The Small Scale Structure of Spacetime

      November 11
      Hegeman 107

      The general theory of relativity tells us that what we call gravity is really a manifestation of the geometry of space and time.  The 100-year-old unsolved problem of quantum gravity is to understand the structure of this spacetime at the smallest scales. Several recent lines of evidence hint that spacetime at very small distances may undergo “spontaneous dimensional reduction,” behaving as if it had only two dimensions rather than four.  I will summarize some of the evidence for this strange behavior, complete with a few pictures of quantum fluctuations of spacetime, and talk about what it means for “dimension” to be a physical observable.  Although the scales involved are tiny — a billionth of a billionth of the size of a proton — it is conceivable that this effect could be measurable; I’ll talk about that possibility, and what it would mean for physics.

      Astronomy Night!

      November 3
      Stevenson Athletic Center, Soccer Field

      We will observe the Moon, Venus, Mars and if we are lucky, the Orionid meteor shower. (In case the sky is not clear the event moves to the next Thursday, same time and place)
      For more information contact Eleni Kontou at

      The Bard College and Columbia University Engineering Partnership: Information Session on the Combined Plan Program

      October 21
      Hegeman 204

      Rebecca Schiavo, Senior Assistant Director from Columbia's Office of Undergraduate Admissions, will be coming to talk about the 3+2 and 4+2 BA/BS Combined Plans. This is an ideal opportunity to get definitive answers to your specific questions. She visits only once in two years, so don't miss her talk.  


      Testing the Hydrogen Bomb:
      The Marshall Islands Story

      October 21
      Hegeman 107

      In the 1940s and 1950s, the United States performed 67 nuclear weapons tests in the Marshall Islands, including the detonation of the largest hydrogen bomb (15 megatons), named Bravo. Seventy years later, the impact of these tests on the Marshallese people is still apparent. As an example, the more recent challenge of rising sea levels coupled with the remaining nuclear waste represents a particularly chilling problem. Here, we discuss our recent publication on this topic as well as future research plans.


      You're Just Going Through a Phase:
      The 2016 Nobel Prize in Physics

      October 7
      Hegeman 107

      This year's Nobel Prize in physics, awarded to David Thouless, Duncan Haldane, and Michael Kosterlitz, recognizes how simple, but often hidden, numbers, can underlie apparently complex phenomena. Touching on superconductivity, magnetism, physics in other dimensions, and the many ways to get lost in the woods, I'll give a general audience introduction to the theories of topological order that the laureates developed, and discuss how these theories both explained puzzles of the past and have helped predict new effects, materials, and devices that may form the foundation for tomorrow's technologies.
      Pizza and refreshments will be provided!

      Bard Summer Research Institute Poster Session

      September 29
      Reem-Kayden Center

      Summer Research Presentations

      September 23
      Hegeman 107

      Testing the quantum hall effect in hybrid graphene
      Nowell Stoddard and Kai Naor
      Bard Nanolab
      Mentor: Paul Cadden-Zimansky

      Over the summer we worked in the Bard Nanolab to fabricate graphene samples and create devices capable of measuring hall resistance at low temperature and high magnetic field. The goal of these devices was to study the quantum hall effect, a unique property of two dimensional semiconductors at high magnetic field. This effect has been studied extensively in monolayer graphene but our aim was to study it in Hybrid graphene, that is, graphene that contains both a single and a double atom layer on the same piece. On the last week were able to go to down to the national magnet lab to test our devices.

      Modelling Exoplanetary Microlensing
      Eleanor Turrell
      Quantum Gravity Group, Marseille France
      Bard College & ISSI Bern Switzerland
      Mentors: Eleni Kontou & Hal Haggard

      Exoplanets act as gravitational lenses by bending light as it moves from a distant source star toward Earth. We created hypothetical light curves to characterize exoplanets if microlensing is observed. We looked at configurations including one lens, two lenses, and plan to examine three lens configurations next.

      Pre-Processing and Classification of Hyperspectral Imagery Via Selective Inpainting
      Victoria Chayes
      University of California, Los Angeles
      Mentors: Wei Zhu, Andrea Bertozzi, & Stan Osher

      We devise a semi-supervised means to classify and sharpen a hyperspectral image. Hyperspectral imagery (HSI), wherein sensors capture data at hundreds of different wavelengths, has numerous applications in agriculture, environmental science, mineralogy, medical imaging, and surveillance, because of its fundamental ability to allow the identification of separate objects or materials that cannot be differentiated on sight. By discarding identified "noisy" pixels and applying an accelerated proximal gradient inpainting scheme, we are able to de-noise pixel signatures and sharpen bands, leaving a clear enough hyperspectral image that clusters can be identified purely by Euclidean distance from pre-known endmembers.

      Pizza and refreshments will be provided!

      Teaching Physics as a Pursuit

      September 16
      Hegeman 107

      The assumption remains pervasive that the core objective of science instruction is a body of canonical knowledge. It underlies instructional practices, assessments of learning, and even progressive “inquiry-based” curricula. Meanwhile, for many students, physics class is still disconnected from genuine pursuit of understanding.

      The assumption, I suggest, is a “misconception” of the community as a system. If “physics is what physicists do,” then physics is a pursuit of understanding. But, like a student who keeps thinking force causes motion, the physics education community keeps thinking the goal is a particular set of concepts.   

      I argue for concerted effort to address the misconception, of research as well as of design and politics. The point is not to eliminate the canon but genuinely to prioritize students’ learning physics as a pursuit. I will discuss challenges and possibilities for curriculum, assessment, and responsive teaching, with video examples from a college introductory courses.

      Astronomy Night!

      September 15
      Lorenzo Ferrari Soccer Complex

      We will observe the Moon, Saturn, Mars and more with the Physics Program’s telescope. (In case the sky is not clear the event moves to the next Thursday, same time and place)
      For more information contact Eleni Kontou at

      Are you a first-year NOT majoring in a science*?

      September 12
      RKC second floor pods

      The assessment is done in pairs, takes a little more than 90 minutes to complete, is designed to see how you go about finding the answer to a science-related question, and is pretty fun to do! Treats provided for all who participate!

      **science majors are always welcome!**

      Bring a laptop for the assessment

      Summer Research Presentations

      September 9
      Hegeman 107

      A Detection Algorithm for Microlensing Events in Wide-Field Surveys
      Daniel Godines Alcantara
      Las Cumbres Observatory in Santa Barbara, California
      Mentors: Rachel Street and Etienne Bachelet

      I used recently released data from the Palomar Transient Factory (PTF) to model microlensing events with the goal of ultimately creating an algorithm that could detect these events as they began to occur. Using statistics to differentitate between different object classes (ie supernova, galaxies, RR Lyrae, etc..) I wrote a program that compares lightcurve statistics to those known to be microlensing, and then decides whether it is a microlensing lightcurve or not. We hope to have the software running at high efficiency in 2017, as the next phase of the survey (ZTF) is released.

      Complex Trajectories and Quantum Mechanics
      Max Meynig
      Quantum Gravity Group, Marseille France
      Mentor: Hal Haggard

      Feynman’s path integral provides a beautiful conceptual link between the quantum and classical realms. A particularly useful manifestation of this link is in the semiclassical approximation where certain classical trajectories can be used to approximate the path integral. Semiclassics breaks down when tunneling problems are treated as there are no classical trajectories connecting opposing sides of the barrier. To properly treat tunneling problems with semiclassical methods the classical dynamics must be extended to the complex plane.

      Improving the performance of automated program repair using learned heuristics
      Liam Schramm
      University of Colorado, Colorado Springs
      Mentor: Jugal Kalita

      Pizza and refreshments will be provided!

      Senior Project Poster Session

      May 17
      Reem-Kayden Center

      Novel Electronic Transport in Topological Insulators and 2D Semimetals

      May 13
      Hegeman 107

      The notion of symmetry-protected topological order in electronic systems has transformed our understanding of condensed matter systems. This notion led to the prediction and discovery of quantum spin Hall systems, 3D topological insulators, topological semimetals, and more. However, electronic transport measurements of such systems have been notoriously challenging due to the difficulty of synthesizing high purity crystals and fabricating devices without causing degradation. To surmount these challenges, we have developed techniques for fabrication of van der Waals heterostructure devices in a controlled environment. In our electronic transport measurements, conducted at cryogenic temperatures, we utilize electrostatic gates and large magnetic fields as powerful experimental knobs. First, I will present our work on the realization of independently accessible surface states on the 3D topological insulator Bi1.5Sb0.5Te1.7Se1.3. Second, I will discuss  our more recent experiments on WTe2, which is expected to be a quantum spin Hall system in the monolayer and has a large, non-saturating magnetoresistance in its 3D form. By thinning the crystal to a few atomic layers, the magnetoresistance can be turned on and off by changing the carrier density, which can be modeled as a transition from a semimetal to a simple metal. This is a promising step toward the realization of 2D van der Waals topological systems.

      Much Ado About Nothing:
      Creating Particles from Vacuum

      April 29
      Hegeman 107

      The quantum vacuum is not empty: in fact it is inherently unstable, and the application of an external electric field can lead to the production of electron-positron pairs. This "Heisenberg-Schwinger effect" was one of the first non-trivial predictions of quantum electrodynamics (QED), but the effect is so weak that it has not yet been directly observed. However, new developments in ultra-high intensity lasers come tantalizingly close to opening a new window on this unexplored extreme ultra-relativistic regime. This has prompted a fresh look at both experimental and theoretical aspects of this and other nonlinear QED effects. I review the basic physics of the problem and describe some recent theoretical ideas aimed at making the elusive Heisenberg-Schwinger effect observable, by careful shaping of laser pulses. This is an example of an emerging new field using ultra-intense lasers to probe fundamental problems in particle physics, gravity and quantum field theory.

      Physics and Complex Numbers

      April 15
      Hegeman 107

      Mathematicians have found it enlightening to extend the real number system to the complex number system. Complex numbers are fascinating in their own right and furthermore they help us to understand the nature of the real numbers. It has been my life's work as a theoretical physicist to examine what happens when we extend real physical theories to complex physical theories. This talk explains in simple terms some of the remarkable insights that we gain by doing so.

      How Will Rainfall Change with Global Warming?

      April 1
      Hegeman 107

      Computer simulations show that global average rainfall increases with surface warming at a rate of roughly 1-3% per Kelvin, but we lack the understanding to estimate this number without resorting to complicated numerical models. This talk will review the basic physics governing mean precipitation, as well as present a new theoretical framework which allows us to intuitively understand as well as quickly estimate this quantity.

      Distinguished Scientist Scholar Award
      Application Guidelines

      March 10 - April 1

      Please see the link below for information on applying for a Distinguished Scientist Scholar Award.
      Application deadline is Friday, April 1

      Direct Detection of 
Gravitational Waves from the Cataclysmic Dance of Two Black Holes

      February 19
      Hegeman 107

      The first ever direct detection of ripples in the fabric of spacetime was reported on February 11th, 2016. This thrilling measurement not only confirms Einstein's prediction of these ripples, but is the first observation of a pair of black holes that dance and merge in the sky. I will recall the surprising history of Einstein's prediction and explain the technological ingenuity and perseverance that the Laser Interferometer Gravitational-Wave Observatory (LIGO) team brought to the measurement of these waves.