Physics

News & Events

Thursday, March 30, 2017

Targeting Mitochondria for the Treatment of Neurodegenerative Disease

Sara Lagalwar, Skidmore College


Time: 12:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Thursday, March 30, 2017

From the Ham Sandwich to the Pizza Pie:
An Introduction to Topological Combinatorics

Steve Simon, Mathematics Program

Given any 3 shapes in R3 (e.g., a piece of ham, a hunk of cheese, and a slice of bread), does there exist a single plane that simultaneously cuts each shape into two pieces of equal volume? Can any shape in R2 be dissected into four pieces of equal area by some pair of perpendicular lines? By exploiting hidden geometric symmetries, we will show how equipartition problems such as these can be solved using powerful techniques from the seemingly unrelated eld known as algebraic topology. For instance, the positive answer to the rst problem above { the so-called Ham Sandwich" Theorem { ultimately reduces to a very deep result of Borsuk and Ulam: for any continuous map from a sphere to a plane, there must exist a pair of antipodal points on the sphere whose images coincide. While fairly advanced mathematics is not too far away, this talk requires only a familiarity with the intermediate value theorem to be understood. All are welcome to attend!
Time: 4:45 pm
Location: Hegeman 308
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Thursday, March 30, 2017

Protein Folding: Seeing is Deceiving

 

Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth. -Sherlock HolmesGeorge RoseJenkins Dept. of BiophysicsJohns Hopkins University 

We challenge the time-honored conviction that proteins realize their native folds via specific favorable interactions, proposing instead that an imprint of the fold is selected primarily by elimination of unfavorable interactions.  Two types of energetically disfavored interactions are considered here: steric clashes and polar groups lacking hydrogen-bond partners. Both types are largely excluded from the thermodynamic population, winnowing that population progressively as the protein becomes compact.  Compaction is accompanied by the entropically favored release of solvent shells around apolar groups.  Remarkably, both solvent shell release and excluding interactions are somewhat non-specific, yet together they promote highly specific chain organization.  For example, exhaustive conformational enumeration of a test hexapeptide reduces 1.5x1012 conceivable conformations to the experimentally-determined dominant population in aqueous solution – this despite deliberate neglect of attractive interactions.
 
Time: 7:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Thursday, April 6, 2017

Canaries in the Saltmarsh:
Tidal Marsh Conservation in the Face of Sea Level Rise

Chris ElphickUniversity of Connecticut


Time: 12:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Thursday, April 6, 2017

Healing, Service, Research, Activism:
An Introduction to the Health Professions

Helen Epstein, Professor of Human Rights and Global Public Health


Time: 5:00 pm
Location: RKC 115
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Thursday, April 13, 2017

Psychosocial Adversity the Epigenetic Origins of Health Disparities

Allison Appleton, SUNY Albany 


Time: 12:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Thursday, April 13, 2017

Early Life Adversity and the Risk of Depression in Young Adulthood

Melissa Tracy, SUNY Albany


Time: 4:45 pm
Location: RKC 111
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Thursday, April 20, 2017

The Ecology of West Nile Virus in the United States

 

Sarah Bowden, Cary Institute for Ecosystem Studies 


Time: 12:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Thursday, April 27, 2017

Molecular mechanisms of SLUG-induced Chemotherapeutic Resistance in Triple-negative Breast Cancer (TNBC)

 

Charvann BaileyVassar College


Time: 12:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Thursday, April 27, 2017

Is Empathy Necessary for Morality?

Dr. Jean Decety | University of Chicago

Empathy, the ability to perceive and be sensitive to the emotional states of others, motivates prosocial and caregiving behaviors, plays a role in inhibiting aggression, and facilitates cooperation between members of a similar social group. This is probably why empathy is often and wrongly confused with morality. Morality refers to prescriptive norms regarding how people should treat one another, including concepts of justice, fairness, and rights. Drawing on empirical research and theory from evolutionary biology, psychology and social neuroscience, I will argue that our sensitivity to others’ needs has been selected in the context of parental care and group living. One corollary of this evolutionary model is that empathy produces social preferences that can conflict with morality. This claim is supported by a wealth of empirical findings in neuroscience and behavioral economics documenting a complex and equivocal relation between empathy, morality and justice. Empathy alone is powerless in the face of rationalization and denial. It is reason that provides the push to widen the circle of empathy from the family and the tribe to humanity as a whole.

 
Time: 4:45 pm
Location: RKC 111
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Thursday, May 4, 2017

Collective Dynamics of Microbes in Natural Sediment

Alexander PetroffRockefeller University


Time: 12:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Thursday, May 11, 2017

Fragments, Fungi, and Feedbacks:
Can Fungal Pathogens Help Maintain Prairie Plant Diversity in Fragmented Landscapes?

Michelle HershSarah Lawrence College 


Time: 12:00 pm
Location: Reem-Kayden Center Laszlo Z. Bito '60 Auditorium
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Friday, May 19, 2017

Marco Spodek senior recital


Time: 8:00 pm
Location: Blum Hall
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Monday, March 12, 2018

Getting in to Medical School…And What I Learned on the Way!

Matthew Lampeter, class of 2017


Time: 4:30 pm
Location: RKC 111
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Past Events

  • 2017
  • 2016
  • 2015
  • 2014
  • 2013
  • 2012
  • 2011
  • 2010
  • 2009
  • 2008

    • 2014

      Senior Project Poster Session

      December 11
      Reem-Kayden Center

      Students presenting: 

      Oliver Bruce, Michael DiRosa, Jacob Fauber, Andy Huynh, Caitlin Majewski, Henry Meyers, Cameron West, Clare Wheeler

      Advisers:
      Rebecca Thomas, Matthew Deady, Keith O’Hara, James Belk, Csilla Szabo, Sven Anderson, Sarah Dunphy-Lelii, Christopher LaFratta



      Watching the Wave Function Collapse

      December 3
      Hegeman 107

      Recent advances in superconducting quantum bits and quantum limited amplifiers have enabled a number of experiments that probe fundamental questions in quantum optics, open quantum systems, and continuous measurement. I will describe recent experiments where we use weak, continuous measurement to monitor the evolution of a superconducting qubit as it evolves in competition between driven evolution and the random evolution associated with measurement. By tracking individual quantum trajectories that evolve between an arbitrary choice of initial and final states we can deduce the most probable path through quantum state space. These results reveal the rich interplay between measurement dynamics, typically associated with wave function collapse, and unitary evolution of the quantum state as described by the Schrödinger equation.


      Using the Earth as a Polarized Electron Source to Search for Long-Range Spin-Spin Interactions

      November 19
      Hegeman 107

      Many extensions of the standard model of particle physics predict the existence of long-range spin-spin interactions. We have developed an approach which uses the Earth as a polarized spin source to investigate these interactions.  We combine recent deep-Earth geophysics and geochemistry results with precise tabulations of the geomagnetic field to create a comprehensive map of electron polarization within the Earth.  We examine possible long-range interactions between these spin-polarized geoelectrons and the spin-polarized electrons and nucleons in three laboratory experiments.  By combining our model and the results from these experiments we establish new stringent bounds on torsion gravity and possible long-range spin-spin forces associated with the virtual exchange of either spin-one axial bosons or unparticles.  The resulting bound on the spin-spin force between an electron and a neutron is one million times smaller than their gravitational attraction.



      Believing We're Seeing the Big Bang*
      (*or, a time shortly thereafter)

      November 12
      Hegeman 107

      Not long after the Big Bang (in cosmic time), the universe went through a transition from being filled with hot, glowing, opaque plasma to being a dark and transparent nursery for the formation of stars and galaxies. An afterglow of light from that early plasma epoch still lingers, giving us a glimpse of a very different universe more than thirteen billion years ago. Observations of this microwave-wavelength light (called the Cosmic Microwave Background, or CMB) have enabled profound insights into cosmic structure and history and helped to establish the current standard cosmological model.  

      In recent years, some of the most important CMB discoveries have been made by ground-based telescopes, including the South Pole Telescope. Studying the CMB from the ground is exceptionally difficult because the earth's atmosphere glows in microwaves — ten million times brighter than the faint signals we hope to discern from deep space. In this talk I will describe some clever observing and data analysis tricks we use to disentangle CMB signal from atmospheric noise, and reveal what goes on behind the scenes to turn raw and messy South Pole Telescope data into something we "believe" — compelling new evidence to test and refine cosmological models.


      Quantum Mechanics in Non-Inertial Reference Frames

      October 22
      Hegeman 107

      Among the key physical principles that underlie quantum mechanics are the principle of superposition (quantum states can be combined to produce other states) and the principle of relativity (all inertial reference frames are equivalent). These two principles are synthesized and implemented in quantum theory by means of unitary representations of the relevant spacetime symmetry group—Galilei group in the nonrelativistic case and the Poincare group in the relativistic case. In fact, much of the essential structure of quantum mechanics is determined by these group representations. They provide us with a means to derive and understand emblematic features of the theory, such as the Heisenberg commutation relations, Schrodinger equation and discrete values of angular momentum.  However, since the principle of relativity as encoded in Galilei and Poincare groups is a statement about inertial reference frames, a quantum theory based on these groups is also a theory, much like Newton's mechanics,  that holds in inertial reference frames. In this talk, I will present my recent attempts to expand the notion of relativity to include accelerating, noninertial reference frames and develop a quantum theory grounded on the unitary representations of the groups of transformations that tie together noninertial reference frames. I will discuss how the resulting formalism allows us to understand the nature and role of some signature features of noninertial reference frames, including fictitious forces and the equivalence principle,  in the quantum setting.

      The Invention of Blue: The 2014 Nobel Prize in Physics

      October 15
      Hegeman 107

      Fall in the Hudson Valley and the trees are displaying their full array of colors, but noticeably absent from this spectrum is blue. A similar absence had for many decades left a vacancy in the production of artificial light. While the semiconductor revolution brought with it computational advances in the form of transistors, energy advances in the form of photovoltaic solar panels, and illumination advances in the form of light emitting diodes, the creation of a solid state source of purely blue light remained elusive. In this talk I’ll give an overview of how Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura, the 2014 Nobel Laureates in physics, overcame technical and non-technical barriers to create the first sources of blue light, and explain why this color holds the key to setting off a 21st century revolution in energy efficiency.


      Relaxation and Thermalization in Isolated Interacting Quantum Systems

      October 8
      Hegeman 107

      We consider one-dimensional isolated interacting quantum systems that are taken out of equilibrium instantaneously. Three aspects are addressed: (i) the relaxation process, (ii) the size of the temporal fluctuations after relaxation, (iii) the conditions to reach thermal equilibrium. The relaxation process and the size of the fluctuations depend on the interplay between the initial state and the Hamiltonian after the perturbation, rather than on the regime of the system. They may be very similar for both chaotic and integrable systems. The general picture associating chaos with the onset of thermalization is also further elaborated. It is argued that thermalization may not occur in the chaotic regime if the energy of the initial state is close to the edges of the spectrum, and it may occur in integrable systems provided the initial state is sufficiently delocalized.

      Bard Summer Research Institute Poster Session

      September 23
      Reem-Kayden Center

      Join faculty and students who participated in this year's Bard Summer Research Institute in presenting their work!


      Maker Faire!

      September 20

      The Science, Mathematics & Computing Division will be sending a bus down to the New York Hall of Science in Queens, NY on Saturday, September 20. Space on the bus is LIMITED. The bus will depart RKC promptly at 9 a.m. and return to campus at approximately 7 p.m.

      Tickets to get into the Faire and a spot in the van are $30.00.  

      CASH ONLY, EXACT CHANGE ONLY.
      Reservations will be accepted until Friday, September 12

      TO RESERVE YOUR TICKET AND A SPOT IN THE VAN, 
PLEASE SEE MEGAN KARCHER, RKC 219. Office hours are Monday-Friday, 8:00-4:00 p.m.


      Planetary Science From the Top Down:

      The Exoplanet Opportunity

      September 17
      Hegeman 107

      What started as a trickle in the mid 1990's is now a torrent, with over one thousand extrasolar planets currently known, and thousands of candidates awaiting confirmation. The study of exoplanets has already revolutionized our view of planet formation, and will soon do the same to our understanding of planetary atmospheres and interiors. The diversity of exoplanets gives us the leverage to crack hard problems in planetary science: cloud formation, atmospheric circulation, plate tectonics, etc. However, the characterization of exoplanets presents a challenge familiar to astronomers: our targets are so distant that we only see them as unresolved dots. I will describe how we can extract spatially-resolved snapshots of planets from such observations. These data are sufficient to constrain low-order climate models and therefore give us insight into the effects of clouds, heat transport, and geochemical cycling. Coarse measurements for a large number of planets are the perfect complement to detailed measurements of Solar System worlds. That is the exoplanet opportunity.

      Summer Research Presentations

      September 10
      Hegeman 107

      Quantum and Fractional Quantum Hall Effects in Hybrid Graphene
      Bard Nanolab,  Bard College
      By: Andrés Martinez de Velasco, Daniel Waldo, Maya Weingrod Sandor
      Graphene is a two-dimensional allotrope in which the classical Hall Effect exhibits a quantization of available electronic states in the material which produces ballistic--zero resistance--conduction. This can be seen in Hall voltage measurements at high magnetic fields where dips to zero in the transverse resistance and plateaus in the longitudinal resistance appear. This phenomenon is known as the Quantum Hall Effect and requires strong magnetic fields and very low temperatures for its observation. In order to study this phenomenon, samples of graphene on Boron Nitride were fabricated using a variety of techniques and procedures, ultimately yielding samples with various four terminal measurement options available.
      Transportation of Ultra-Stable Light via Optical Fiber Laser Interferometer Gravitational-Wave Observatory (LIGO)
      California Institute of Technology
      By: Emily Conant
      It has been demonstrated that polarization-maintaining single mode optical fiber can be used to transport frequency-stable light. It is desired to transport stable light to other labs in the building to serve as a frequency reference for various experiments investigating different sources of noise in gravitational-wave detectors. Stable light has been obtained from ultra-stable Fabry-P'{e}rot cavities by use of the Pound-Drever-Hall locking technique. We have mode matched stable light into the fiber and are using a double-pass acousto-optic modulator (AOM) configuration to cancel fiber phase noise. We use a beamsplitter to interfere the stable light and double passed light onto a photodiode as a homodyne detection, which is connected to a phase-locked loop (PLL) to measure the beat frequency. From there, we analyze the noise in the system by measuring the power spectral density of the PLL control signal with a spectrum analyzer. We have measured the expected dominant sources of noise in the system by using a similar PLL set-up and suppressed them.  We cancel the fiber phase noise by locking the optical beat to the signal generator in the PLL.  
      Characterization of Nanowires for Red LASER on {001} Silicon
      Center for Photonics and Multiscale Nanomaterials
      University of Michigan
      By: Trevor LaMountain
      As technology decreases in size, electronic systems, like those found on a microchip, encounter a scaling problem.  The resistance of a current carrying wire is inversely proportional to its cross-sectional area.  This large resistance in microelectronic systems leads to slower, less efficient devices.  Fortunately, photonics systems, using photons to carry information instead of electrons, do not encounter such scaling problems.  It is therefore desirable to replace certain components of microelectronic systems with photonics.  However, in order to create such an integrated system, we require a coherent light source (LASER) that can be constructed on the same {001} silicon substrate that modern microchips use.  In this talk I discuss the novel methods used to create a red-emitting laser structure on {001} silicon, and in particular highlight the material characterization methods used to measure the composition of alloys used in this device.

      Summer Research Presentations

      September 3
      Hegeman 107

      Single-molecule Conductance as a Tool for Understanding Solar Cell Efficiency
      Columbia University with the Energy Frontier Research Center 
in the Applied Physics and Mathematics Division
      By: Ingrid Stolt

      In this project, Scanning Tunneling Microscope-Break Junction (STM-BJ) techniques were used to measure the single-molecule conductance of a group of compounds each containing a different central unit (a molecule sandwiched  between a distinct pair of atom chains). Many of these central units have been implemented in the design of organic semiconductors for Organic Photovoltaic (OPV) devices. The goal was to use these conductance measurements to gain an understanding of the structural and electronic properties of these compounds in order to further understand why the central units lead to high/low  efficiency when used in OPVs. The presentation will be a summary of the measurements done on one particular compound and how the results can be interpreted.


      Electron spin resonance on-a-chip
      National High Magnetic Field Laboratory
      By: Henry Clark Travaligni

      We discuss Electron Spin Resonance Spectroscopy (ESR), and develop a room temperature measurement set up for ESR measurements performed on a high dielectric substrate.




      Pre-health Professions 101: How to Prepare

      August 25
      RKC 101

      Professor Frank Scalzo
      Health Professions Adviser, Bard CollegeProfessor Scalzo will introduce the pathways leading to post-baccalaureate degrees in the health professions, including allopathic medicine, osteopathic medicine, veterinary medicine, dentistry, optometry, etc. etc. The discussion will be tailored to the interests of the audience.  If you are interested in a health profession, but have not attended a similar previous discussion, you should attend this one.


      Senior Project Poster Session

      May 15
      Reem-Kayden Center

      Exploring Nanoscale Material Properties through Quantum Mechanics and High-Performance Computing

      April 22
      RKC 115

      Density functional theory (DFT) is a powerful method used to obtain solutions to the many-electron Schrӧdinger equation in condensed matter systems, and calculations using DFT are particularly well-suited for parallelization over as many as several thousand computer cores. DFT can be used to study the structural, electronic and vibrational properties of nano-structured materials from a first-principles perspective without the need for experimental parameterization. In this talk, I will discuss various DFT calculations and their applications to nano-materials of technological relevance, in particular materials for future device technology. Specific applications include mapping the free energy landscape for impurity diffusion across semiconductor interfaces, understanding the enhanced electrical conductance of ultra-small metallic  nanowires, and tuning the electronic properties of carbon nanotubes through the dielectric environment. These studies suggest new ways of manipulating quantum transport in atomic scale materials.


      Inelastic Collisions of NaK and NaCs Molecules with Atomic Perturbers

      April 17
      Hegeman 107

      I will discuss our studies of inelastic collisions of gas phase NaK and NaCs molecules with various atomic perturbers (Ar, He, K, Cs) using the spectroscopic technique optical-optical double resonance. The experiment is conducted by means of laser induced fluorescence (LIF) and polarization labeling (PL) spectroscopy. From the combination of LIF and PL spectra, we can determine certain properties of the inelastic collision. Such properties include perturber dependent collision rate coefficients, observations of strong propensities for ΔJ=even transitions in some cases, fraction of orientation lost in rotationally inelastic collisions, rate coefficients for vibration changing collisions, and collision line-broadening rates.