Date

Talk

Thursday
Sept 13

Student Summer Research Poster Session

Union College Summer Research Students

Students will present posters about their summer research projects.

Thursday
Sept 20

Tracing Galaxy Evolution over 9 Billion Years with the FLAMINGOS Extragalactic Survey

Eric McKenzie
Colgate University

The FLAMINGOS Extragalactic Survey (FLAMEX) is a major photometric near-infrared galaxy survey with over 50,000 galaxies to date. I will give an overview of this survey and its partner surveys in optical and mid-infrared light. I'll also discuss how I'm using FLAMEX to expand our knowledge of galaxy evolution. In the local universe, galaxies in dense regions are much more likely to have reddish colors (and thus less star formation) and elliptical shapes. This density-color-morphology relation gives us some insight into how environment affects the development of galaxies, but hammering out the details of the physical processes can be tricky. I trace how the density-color relation has been changing across the past 9 billion years to place constraints on evolutionary timescales.

Thursday
Sept 27

Talk is Cancelled and will be Rescheduled for Later Date!

Development of Single Electron Devices & Hybrid Nanostructures

Kim M. Lewis
RPI

My research program develops nanotechnology as it relates to the emergence of hybrid nanostructures and single electron devices (SEDs). In particular, we study prophyrin molecules for its energy storage and light harvesting capabilities, which are properties essential for solar cell devices. Topography and electrical characteristics of the molecule are studied using conductive atomic force microscopy. Finally, chemical sensors are being developed to detect volatile organic compounds (VOCs) and chemical warfare agents (CWAs) based on the use of gold nanoparticles as the sensing element.

Thursday
October 4

Semiconductor Quantum Dots - New Ideas in Energy Conversion

Peter Persans
RPI

TBA

Thursday
October 11

Galaxy Transformation in the Virgo Cluster

Hugh Crowl
U. Mass. Amherst and Hampshire College

The nearby Virgo Cluster provides an ideal laboratory to study galaxy-galaxy and galaxy-cluster interactions at a level of detail impossible at larger distance. I will present results of a study on where and when Virgo spiral galaxies are stripped of their star-forming gas. Through the use of optical imaging, UV imaging, and optical spectroscopy, we are able to gain insight into the locations of gas stripping in the Virgo Cluster and how that stripping progresses. In two cases, we have been fortunate enough to catch galaxies in the process of being transformed, and I will talk in detail about those "case studies." Additionally, I will present a larger sample of galaxies and discuss implications for galaxy transformation in Virgo.

Thursday
October 18

Silicon Microprobes for Arrhythmia Detection

Fred von Stein, '01
Cornell University

Sudden cardiac death remains a leading cause of mortality in the US and other developed countries, with over a quarter million deaths a year in the US alone. Despite decades of intensive investigation, the underlying causes of the lethal arrhythmia ventricular fibrillation (VF) still remain unknown. Recently, several promising hypotheses regarding the mechanism for VF have been introduced. However, it has not been possible using currently available experimental techniques to determine which theory (or theories) is most applicable to VF. Current models of VF are based off of experimental data which have been limited to the surfaces of the heart. We have used nanofabrication techniques to build silicon-based microprobes which can measure electrical activity below the surface with high spatial and temporal resolution. These microprobes can be used in an array to record from multiple sites, creating an activation-repolarization map in three dimensions. The results of this study will lead to advances in understanding wave propagation in cardiac tissue during normal cardiac rhythm and the changes that occur during VF.

Thursday
October 25

Deriving Newton's F = ma from Information Theory

Ariel Caticha
University at Albany

The laws of physics are not laws of nature. Weird? Outrageous? But what if the laws of physics were nothing more than rules to process information about the world? Would we be able to tell? Yes, because then it would be possible to derive physics directly from standard rules of inference applied to the information that is relevant to the physical question at hand. Newtonian dynamics is derived from prior information codified into an appropriate statistical model. The basic assumption is that there is an irreducible uncertainty in the location of particles so that the state of a particle is defined by a probability distribution. The corresponding configuration space is a statistical manifold the geometry of which is defined by the information metric. The trajectory follows from a principle of inference, the method of Maximum Entropy. There is no need for additional "physical" postulates such as an equation of motion, or an action principle, nor for the concepts of mass, momentum and of phase space, not even the notion of time. The resulting "entropic" dynamics reproduces the Newton's mechanics for any number of particles interacting among themselves and with external fields. Both the mass of the particles and their interactions are explained as a consequence of the underlying statistical manifold.

Thursday
November 1

The ALFALFA Survey: A Hunt for Low-mass and Starless Galaxies

Sabrina Stierwalt
Cornell University

I will present recent results from the ongoing, blind HI survey ALFALFA which uses the sensitivity and angular resolution of the Arecibo telescope to study the HI content of the local universe. ALFALFA promises to detect ~30,000 HI-bearing objects including high velocity clouds of unknown origins circling the Milky Way, tidal streams ripped from galaxies during galactic collisions, and galaxies with largely extended HI disks. By looking for gas, ALFALFA also detects very low-mass and low surface brightness dwarf galaxies that were missed by previous optical surveys.