SPICE Student ColloquiumWhat is SPICE?SPICE: Student Projects for Intellectual Community Enhancement. Graduate students in physics and applied physics received a grant from the Office for the Vice Provost for Graduate Education "to develop innovative activities to expand the intellectual community of their department or program." As part of our program, we created a student colloquium, open to all students interested in physics and applied physics. See the main page for the Physics and Applied Physics SPICE program.The SPICE Student Colloquium is designed to bring graduate students in our departments together to learn about research outside of our fields and to foster a vibrant intellectual community. We strongly encourage questions from the audience and discussion after the talks. For this reason, we suggest limiting talks to about 30 minutes. We hope the relaxed atmosphere and interesting colloquia will become a long-lasting part of the graduate experience in Physics and Applied Physics at Stanford. Got an idea for a talk or a suggestion for the organization? Contact the organizer, Paul, to get on the schedule. Sign up for our email list so that you get reminders about upcoming events and changes to the schedule. Unsubscribe at the link above if you get tired of hearing from us. Unless otherwise noted, all colloquia are on the first Thursday of the month, at 12:00 p.m. in Physics & Astrophysics 102. Lunch will be provided, but come on time before it runs out. Summer 2009June 11Josh Weinstein The Physics of the Immune System Five hundred million years ago, in an aquatic forest of enormous ecological diversity, a common ancestor to all jawed vertebrates was born with the biological hardware to repel pathogens by trial and error. This microcosm of evolution, which we call the adaptive immune system, was so successful in defending this ancient organism and its progeny that it has been conserved for eons. Such conservation allows us to study our own body’s defenses in the form of one of our simplest evolutionary cousins: the zebrafish. This talk will focus on the burgeoning use of the adaptive immune system in zebrafish as a case study in the dynamics of evolving populations of cells. Specifically, new “high-throughput” sequencing technologies will be shown capable of measuring precisely the diversities and distributions of antibodies: the molecular machines responsible for maintaining immune “memory” in an organism. The surprising result of universality in the distributions of antibody abundances will lead into a discussion of simple but powerful models of immune dynamics. Spring 2009May 7Doug Applegate Dark Matter: What do we actually know? What is dark matter? This is one of the most important questions in basic physics today. Its been more than seventy years since dark matter was originally postulated, with many theories tested and discarded. Even in the last year, we have seen a flurry of results from a diverse range of experiments giving (possibly false) leads in this mystery. So what do we actually know about dark matter? In this talk, I will review the experimental evidence for dark matter as a weakly interacting massive particle. I will also discuss the results that have captured science headlines in the last year, from direct detection of dark matter experiments to cosmic ray excesses from the decay of dark matter, and separate out the questionable conclusions from the hints of exciting new physics. April 2 George Karakonstantakis Transport in 1D Quantum Systems Quantum 1D systems are a lot different from 2D or 3D systems in many aspects. One of them is that they have unusual transport properties. Some of them such as electrical conductivity, spin conductivity and thermal conductivity will be examined in two prototype models which are very pedagogic too: Heisenberg model and Hubbard model. We will investigate various aspects of these models done with many different analytical and numerical methods. At the end we will present a modern and very elegant way of treating these models which is using non-relativistic field theory. Winter 2009Feb. 12Brian Wilt Advances in Light Microscopy in Neuroscience Light microscopy is a versatile tool for studying the cellular and molecular processes underlying fundamental neural phenomena such as learning, memory, development, and disease. Investigators have developed a wide range of optical probes to label and report these processes. Others have pursued optical techniques for non-invasively extracting these signals tucked deep (0.5 mm – 0.75 mm) inside biological specimens. In this talk, we will first briefly motivate some neuroscience and optics background. Next, we will explore bleeding-edge technology that will enable neuroscientists to interrogate the brain with unprecedented resolution, speed, and precision. In particular, we will discuss new imaging techniques for studying the brain in vivo faster, deeper, and in 3D, as well as exciting new tools which can probe sub-diffraction limited length scales (“superresolution”). Fall 2008Naoko Kurahashi Acoustic Detection of Ultra-high Energy Neutrinos What do you get when you mix neutrino physics, particle astrophysics, oceanography, and acoustics, and sprinkle in a touch of US Navy submarines and sunshine from the Bahamas? The SAUND experiment! I'll explain why particle physics predicts ultra-high energy cosmic rays to be neutrinos, what they imply in terms of astrophysics, and the challenge of acoustically detecting these neutrinos in an oceanic noise environment. Nov. 13 Joseph Maciejko How to Take the Square Root of an Electron In 1572, Rafael Bombelli introduced imaginary numbers, although, in his own words, "to many this will appear an extravagant thing". If his boldness in taking the square root of a negative number was rewarded by creating one of the most important fields of mathematics, what kind of "extravagance" can we expect if we are to take the square root of an electron? In this talk, I will discuss how electrons can be broken apart in topologically non-trivial states of condensed matter, such as the quantum spin Hall state which was predicted theoretically at Stanford in 2006 and experimentally discovered last year. Dec. 4 Matt Larson Single-molecule biophysics; Yanking, pushing, and bullying nature's tiniest molecular motors Motion drives life. The synthesis of proteins in our cells, the division and replication of these cells, and even the contraction of individual muscle fibers, are all powered by molecular motors. Using single-molecule techniques, biophysicists are able to observe and bias the motion of these nanometer-sized motors in real time. In my talk I will be discussing the mechanics of RNA polymerase (RNAP), one of nature's most highly regulated motors and the molecule responsible for transcribing the information stored in our DNA into a transient RNA message. Specifically, I will explain how the application of load using optical tweezers has helped to unravel the mechanism by which an otherwise stable molecular complex – consisting of RNAP, the DNA of a specific gene, and the RNA message – quickly dissolves upon reaching a termination signal at the end of a gene. |
| We thank the Office for the Vice Provost for Graduate Education, the Physics Department, and the Applied Physics Department for providing funding for this program. |