http://www.physics.umn.edu/rss/ Events for the week of Monday, February 13th 2012 en-us http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16721 <i>Speaker:</i> Renee Raphael, Department of History, University of Alabama<br/><i>Subject:</i> A Dialogic Revolution: Galileo, Jesuit Readers, and a New Experimental Reading<br/><br/><div class="wikitext"><p>This presentation will address long-held assumptions about the relationship (or lack there-of) between proponents of the 17th-century New Science and purportedly conservative practitioners of Aristotelian natural philosophy. It will do so through a case study that examines Jesuits’ reactions to Galileo’s final publication, his 1638 <em>Two New Sciences</em>. I will show how, even when Galileo embraced novel approaches, Jesuit readers eagerly attempted to integrate his findings within their own bookish natural philosophical enterprise. A closer examination of Galileo’s text, furthermore, reveals that Galileo encouraged such a reading. This case study suggests that current portrayals of seventeenth-century intellectual life require revision to take into account such patterns of dialogic interaction. In particular, I argue that out of such dialogues—like this one between Galileo and his readers—emerged new ways of reading and evaluating texts of the New Science, texts which explicitly invoked experience and experiment to support their claims.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16721 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16431 <i>Speaker:</i> Matthew Hayes (L'Institut de Recherche en Astrophysique et planetologie<br/><i>Subject:</i> Lyman-alpha diagnostics in the epochs of galaxy formation and cosmic reionization<br/><br/><div class="wikitext"><p>By necessity the epochs of rapid galaxy growth/assembly and cosmic reionization were coeval, at roughly redshift z~6-11. While the focus of huge observational onslaughts in the last decade, many pieces of this puzzle remain far from constrained empirically. A non-exhaustive list includes the gas and dust content of young galaxies, the geometry of the circumgalactic medium, the physical mechanisms by which dark matter haloes acquire the gas they need to form galaxies, and the reionization history. In my talk I will present and discuss new observational and modelistic methods by which all of these quantities can be studied, united by the common theme of a single emission line: the n=2-1 transition of neutral hydrogen (HI Lyman-alpha).</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16431 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16761 <i>Speaker:</i> Cynthia Cattell<br/><i>Subject:</i> Solar cycle and solar illumination dependence of auroral ion beams<br/><br/><div class="wikitext"></div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16761 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16351 <i>Speaker:</i> Professor Aviad Frydman, Bar Ilan University, Israel<br/><i>Subject:</i> The Superconducting Insulator<br/><br/><div class="wikitext"><p>The disorder induced superconductor-insulator-transition (SIT) is a rather old topic, however many of its characteristics are still not understood. Recently a number of dramatic experimental features were observed near the SIT such as a large peak in the magneto-resistance, peculiar I-V characteristics, simple activated temperature dependence of the resistance and traces of superconductivity at temperatures above TC leading to a revived interest in the field. One of the biggest puzzles of this topic is the nature of the insulator. In my talk I will present a number of findings obtained by our group as well by others indicating that remnant superconductivity persists into the insulating phase. These include a superconducting energy gap, vortices and little parks oscillations. I will discuss a few scenarios that try to clarify the origin of this "supercoducting insulator".</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16351 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16921 <i>Speaker:</i> Giovanni Franzoni, University of Minnesota<br/><i>Subject:</i> Search for the Higgs Boson in the Gamma Gamma Channel at CMS<br/><br/><div class="wikitext"><p>A search for a Higgs boson decaying into two photons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. This is one of the prominent channels for the Higgs boson discovery, and will continue playing a pivotal role in 2012. The search strategy is applied to the full dataset of 4.76 fb-1 of data collected by the CMS detector in 2011. Current limits on the production cross sections and prospects for 2012 of a Standard Model Higgs boson boson will be presented.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16921 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16731 <i>Speaker:</i> Bryce Beverlin<br/><i>Subject:</i> Coherent oscillations in modeled neuronal networks<br/><br/><div class="wikitext"><p>I present here the study of coherent oscillations in model neurons,<br /> specifically conductance based models and phase response curve (PRC)<br /> models. These individual neural oscillators are noisy so a<br /> functional relationship between the PRC and the variance of the PRC is<br /> developed. In order to study the synchronizability of a network of<br /> oscillators, a second-order connectivity framework is investigated to<br /> reveal the importance of certain connection motifs. The oscillator<br /> networks are then used to develop models of disease states such as<br /> Parkinson's and epilepsy. By periodically forcing the networks, one may<br /> control the degree of synchrony, depending on the frequency and amplitude<br /> of simulation. A closed loop feedback control system is shown to affect<br /> the seizure state and may be used for clinical deep brain stimulation<br /> therapy. This presentation is the public portion of Bryce's PhD final<br /> exam.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16731 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16851 <i>Speaker:</i> Clint Young, McGill University, Canada<br/><i>Subject:</i> Hard-scale probes of heavy-ion collisions<br/><i>Dr. Young is a candidate for a postdoctoral position.</i><br/><br/><div class="wikitext"><p>Hard probes are produced initially and perturbatively in heavy-ion collisions. Numerical simulation of their evolution throughout the collision is necessary, both because of the array of processes to which they are subject and because not all processes are easily simplified to analytic calculations. We use MARTINI for examining the evolution of dijets at the LHC, specifically examining how finite-temperature processes can lead to dijet asymmetry. We also modified MARTINI to simulate the flow of heavy quarks and quarkonium and to examine J/psi suppression. The ability of MARTINI to simulate full events allows for an examination of in-medium hadronization and recombinant production of heavy quarks, which leads to the prediction of significant B_c meson yields.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16851 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16911 <i>There will be no colloquium this week.</i><br/><br/><div class="wikitext"></div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16911 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16191 <i>Speaker:</i> Danielle Berg and Larry Rudnick<br/><br/><div class="wikitext"></div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16191 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=14711 <i>Speaker:</i> Daniel Krefl<br/><i>Subject:</i> B-Model Approach to Refined Partition Functions<br/><br/><div class="wikitext"><p>I will review the B-model approach to refined (aka Omega-deformed) N=2 gauge- and string-theory partition functions put forward in my work during the last 2 years. The B-model approach determines the deformed partition function via invoking special geometry and the holomorphic anomaly equation equipped with new boundary conditions. In particular, from this point of view the Omega-deformation can be interpreted as the radius deformation of the c=1 string. If time permits, I will further discuss some aspects of the decompactification limit, which is special in the sense that it also possesses an interpretation in terms of quantum geometry. The focus of the talk will be more about the general picture rather than on technicalities.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=14711 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=15451 <i>Speaker:</i> Andrey Varlamov, University of Rome<br/><i>Subject:</i> Quantum Fluctuations and Dynamic Clustering of Fluctuating Cooper Pairs<br/><br/><div class="wikitext"><p>We derive the exact expressions for the fluctuation conductivity in two dimensional superconductors as a function of temperature and magnetic field in the whole phase diagram above the upper critical field line Hc2(T). Focusing on the vicinity of the quantum phase transition near zero temperature we arrive to the conclusion that as the magnetic field approaches the critical field Hc2(0) from above, a peculiar dynamic state consisting of <br /> clusters of coherently rotating fluctuation Cooper-pairs forms. We estimate the characteristic size QF( H) and lifetime QF( H) of such clusters and indicate in the corresponding domain of the<br /> phase diagram, where such phenomenon can be observed. The derived values QF( H) and QF( H)<br /> allow us to reproduce qualitatively the available results for the quantum fluctuation<br /> contributions to the in-plane conductivity, magnetization, and the Nernst<br /> coefficient. Finally we predict the existence of a peak in the zero<br /> temperature transverse magneto-conductivity of layered superconductors at<br /> fields above Hc2(0).</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=15451 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=15761 <i>Speaker:</i> Brett L. Walker, Department of History, Philosophy, and Religious Studies, Montana State University, Bozeman<br/><i>Subject:</i> Toxic Archipelago: The Hybrid Causes of Industrial Disease in Japan<br/><i>Refreshments served in Room 216 Physics at 3:15 p.m.</i><br/><br/><div class="wikitext"><p>My lecture explores startling case studies of industrial pollution to demonstrate that industrial toxins that flow through engineered Earth and its technological and ecological systems render useless academic ruminations on the differences between wilderness areas and cities, organic and inorganic, nonhuman and human, biology and technology, or even nature and artifice. Industrial toxins, when finding their way to human bodies, reject such boundaries – even placental boundaries – and so it makes sense that we should, too, when tracing them. Everything on Earth, living or otherwise, is integrated into one interconnected, buffer-less web that is neither artifice nor nature. Some agencies are naturally occurring, others are anthropogenic: both remain relevant to understanding how industrial toxins function, sicken bodies, and cause pain. I argue that with the birth of the Industrial Age came the advent of <em>Homo sapiens industrialis</em>, a new breed of human utterly penetrated, engulfed, and transformed, often at the molecular level, by the engineering, industrializing, and poisoning of the environment in and around them. “The Toxic Archipelago” is the story of Japan’s place in this human transformation.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=15761 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16451 <i>Speaker:</i> Dr. Alberto Bolatto, U Maryland<br/><i>Subject:</i> The Large Scale Picture of Star Formation in Galaxies: Bright Gas, Dark Gas, and Galaxy Evolution<br/><br/><div class="wikitext"><p>The importance of understanding baryonic processes in galaxies to properly interpret large scale cosmological simulations has been known for some time. Only recently, however, has there been<br /> compelling evidence showing that "normal" galaxies evolve mostly not through major mergers (although those produce some truly spectacular examples) but via a combination of cold mode<br /> accretion and star formation. In this colloquium I will review the evidence for passive evolution of galaxies and discuss some of our efforts to better understand the relation between gas and star formation activity in galaxies at present times, and throughout cosmic history.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16451 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16941 <i>Speaker:</i> Leon Hsu, University of Minnesota<br/><i>Subject:</i> Using computer coaches in Fall2011 introductory physics<br/><br/><div class="wikitext"><p>The speaker will talk about the experimental design for using the computer coaches in fall 2011introductory physics class and share some results and feedback from the students.</p> </div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16941 http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16621 <i>Speaker:</i> Boris Shklovskii, University of Minnesota<br/><i>Subject:</i> Physics of super-capacitors<br/><br/><div class="wikitext"></div><br/> http://www.physics.umn.edu/calendar/spa.all/thisweek/index/calendar.html?item=16621