Solid hydrogen is a molecular quantum solid with unusual predicted properties. At very high pressures or densities it is predicted to become a monatomic metal and a possible high Tc superconductor. Atomic metallic hydrogen has never been experimentally observed, while theoretical predictions of the critical pressure for the transition are scattered over a large range. A recently predicted peak in the temperature versus pressure melt line has been considered as a precursor for metallization. We have used an innovative technique to extend the melt line to high temperature and pressures and observed a peak. In this talk I shall review some of the interesting properties of solid hydrogen, and discuss our recent results on its melt line.

Modulation is an important step in the acquisition of polarization measurements. In this talk I will present a new type of polarization modulator, the Variable-delay Polarization Modulator (VPM), that operates only in translation. This differs from the current industry standard, the half-wave plate (HWP), which operates in rotation. The VPM has many advantages over the HWP, and may be well-suited for air- or space-borne
applications. This new device was tested using the Hertz Polarimeter at the Submillimeter Telescope Observatory (SMTO).

The disks surrounding T Tauri Stars have long been assumed to be
environments of the first steps in planet formation, namely, dust
coagulation up to 1 mm in size. Multiwavelength polarization measurements in the submm-mm range may provide information about the sizes of the grains in the disk, and possibly the magnetic field orientation in these environments. I present the first polarization measurement of DG Tau at 350 microns, and compare this data with a previous measurment at 850 microns, as well as the current model available for these disks.

Douglas Allchin
"Teaching Science Lawlessly"
Boyle's law is the epitome of science in the classroom. Yet using recent philosophical perspectives on scientific laws, one can see that Boyle's law is not universal or invariant, as implied by the term 'law'. Indeed, Boyle's law—and other scientific "laws"—are not lawlike at all. In addition, from a cultural studies perspective, we might also examine why we teach laws in science and what it means to name them after someone. Science studies thus seems critically poised to inform science education. Indeed, properly understood, it might well lead us to revolutionize what and how we teach.

Naomi Scheman
"Objectivity as Trustworthiness"
Why does objectivity matter? I argue that its importance stems from epistemic dependency: we are irremediably dependent on others, including institutionally accredited experts, notably scientists, for much of what we need to know. Objectivity is supposed to allow scientists to serve as generic knowers, in part by bracketing the influence of social location. But traditional accounts of objectivity leave unexamined factors crucial to the actual trustworthiness of scientific claims: (1) broader questions of the trustworthiness of the institutions within which science is done; and (2) the relevance of diverse social locations for understanding how the world works.

Alan Gross
"Verbal–Visual Interaction in Science"
Department of Communications Studies, University of Minnesota
My current work focuses on the interaction of words and images in the creation of meaning in the sciences. Since the majority of scientific texts—from laboratory notebooks to published papers—consist of both words and images, an examination of their interaction seems a worthwhile means of illuminating scientific meaning. I approach the problem from the point of view Peirce’s semiotics viewed within the framework of a general theory of cognitive processing, Allan Paivio’s Dual Coding Theory. I ground my work in the philosophy of science of Martin Heidegger, a philosophy that, unlike analytical philosophy, does not privilege the proposition; rather, it places 'seeing as' at the center of the scientific enterprise.

Case-based reasoning (CBR) is the process of solving a real-world problem based on precedent examples and problems. Case-reuse promotes CBR by employing problem pairs that share similarities in deep structure. We conducted 8 focus group learning interviews and 2 individual interviews with 10 students in an algebra-based introductory physics class. During each focus group session, participants were paired together, and each asked to work on a different problem. All problems shared deep structure similarities but had surface differences. After students solved these problems, they were asked to discuss their solutions with their partner briefly and discuss the similarities and differences between each of the problems. During individual interviews, students were asked to rate problem pairs of varying degrees of deep-structure and surface similarity.For this talk, I will present the observations made during the focus group interviews and the results and implications of the similarity ratings. Data were also collected from five multiple choice examinations taken during the semester. While most of the exams focused on traditional problem solving, the last three questions on each examination were non-traditional tasks: jeopardy, text editing and problem posing. Individual scores for each examination question were analyzed, and those results will also be presented for this talk. This work is funded in part by the National Science Foundation under grant DUE – 06185459.

The 'high-Tc problem' remains one of the most important outstanding problems in condensed matter physics today. After two decades of intense research there is no consensus on the basic question: what is the mechanism that responsible for pairing? Even as we explore the possibility that pairing in these unconventional superconductors proceeds without the involvement of a bosonic glue, we have recently made exciting progress in identifying candidates that could potentially mediate pairing. In this talk, I will discuss our recent STM investigations of the electron-doped cuprate superconductor Pr0.88LaCe0.12CuO4-δ (PLCCO) (Tc = 24 K). Our spectra reveal superconducting gaps with coherence peaks that disappear above Tc. In addition, multiple step/peak-like features are observed outside the gap. Such features in STM spectra are suggestive of bosonic excitations that couple strongly to the electrons. Analysis of the data reveals bosonic modes at 10.5±2.5 meV and 3 meV which are much lower in energy than the bosonic mode observed in hole-doped Bi2212. These energy scales match the magnetic resonance modes (spin-excitations) in PLCCO measured by inelastic neutron scattering. I will show that both the local mode energy and the intensity are correlated with the local gap energy scale and discuss the implications of our observations on the pairing issue. I will also briefly discuss recent atomic resolution images and spectroscopy on the parent compound of a pnictide superconductor SrFe2As2. I will compare our data with contradictory LEED on identical samples and explore the possible reasons for this puzzling contradiction.

Semiclassical objects: solitons, bubbles, black holes, etc., can be viewed as field configurations consisting of very many quanta. In certain situations such objects can be formed spontaneously “out of nothing” or/and be produced in a thermal bath or in particle collisions. Some of them, if actually produced in a laboratory, may lead to catastrophic consequences. The impossibility of such a doomsday-type outcome of running high-energy accelerators has been fully tested “experimentally” by the cosmic ray collisions over the history of the Universe. I discuss possible theoretical explanations of this encouraging “experimental result”.

In galaxy clusters, non-thermal components such as magnetic field and high energy particles keep a record of the processes acting since early times till now. These components play key roles by controlling transport processes inside the cluster atmosphere and therefore have to be understood in detail. However including them in simulations is extremely challenging
as the structures in and around clusters are quite complex and span a very large dynamic range in scales. I will report the
status of what can be achieved in numerical simulations of the formation of galaxy clusters in cosmological context and our predictions for the magnetic field structure for different models of magnetic seed fields. This allows us to put constrains on the presence of cosmic ray protons in galaxy clusters by comparing in detail the induced radio emission in
these simulations with observations. Additional, such simulations can be used to constrain the transport and the deflection of UHECRs within clusters and large scale structures.

Niles Eldredge and Stephen Jay Gould's theory of punctuated equilibria is one of those rare scientific theories that has become a part of our broader culture. The theory has been invoked, attacked, explained, and dismissed so often and in so many contexts that it requires almost no introduction. However, despite the attention it has received over the years, a number of questions and misconceptions have persisted about the significance, originality, radicalism, and even authorship of the theory itself. This talk will attempt to peel back some of the layers of mystique, misunderstanding, and mythology that surround punctuated equilibria and will reconstruct-in part using recently-uncovered letters and drafts by Gould and Eldredge-an account of the inception and early development of the original 1972 paper. The talk will also explore the significance of punctuated equilibria for the broader movement of evolutionary paleobiology during the 1970s, and will examine and critique some of the themes in previous historical accounts of the theory.

Non-Gaussian effects in the cosmic microwave background (CMB) can arise either from the primordial phase of the universe or from the subsequent non-linear evolution. I will focus on the latter point and review the perturbation theory beyond linear order. I will detail how the kinetic theory can be used in cosmology to derive the evolution of perturbations for polarized radiation. Finally I will present why the collapse of dark matter is the main source of non-Gaussianity in the CMB on small scales.

A striking manifestation of quantum mechanics is the existence of a dissipationless current in a non-superconducting metal ring. The persistent current is analogous to electrons orbiting the nucleus in an atom, a more familiar quantum effect. The persistent current is a signature of electronic phase coherence around the ring and offers insight into many issues in mesoscopic physics such as coherence and electron interactions in metals. The prediction that an atom-like persistent current could be observed in a micron size metal ring generated considerable interest. However, the small magnitude of the current and the necessity of measuring it through its associated magnetic moment make persistent current experiments challenging. Few measurements have been reported and inconsistent results have left an unclear picture of the properties of persistent currents. In a novel approach to studying persistent currents we have developed a cantilever based torsional magnetometer capable of detecting a magnetic moment of 1 μB/Hz1/2 (and a force of 1.6 aN/Hz1/2) at a temperature of 300 mK. The rings are integrated directly onto the end of the cantilever. I present measurements of persistent currents in arrays of rings and single rings as a function of temperature, ring size, and magnetic field over a much broader range than previously possible. We compare our results to theory and previous experiments.

This colloquium will provide an introduction to the physics of spin transport in solids, with an emphasis on semiconductors. I will focus on the roles played by tunneling, spin-orbit coupling, and hyperfine interactions in the injection, transport and detection of spin-polarized electrons. Examples from experiments on ferromagnet-semiconductor junctions will be used to illustrate some of the unusual physics associated with these phenomena. The technological implications will be discussed briefly (and somewhat skeptically).

We develop an exact non-perturbative framework to compute the nonequilibrium steady state properties
of quantum impurities connected to leads subject to source-drain voltage. We show that in the open system limit the
non-equilibrium physics is captured by open system eigenstates de¯ned with boundary conditions set by the leads.
The eigenstates are current carrying and entropy producing, with the dissipation inherent in the limit.
We construct these eigenstates by means of a recently introduced Scattering (or Open) Bethe Ansatz approach, a
generalization to nonequilibrium of the Thermodynamic (or Closed) Bethe Ansatz. We compute the I(V) curve of the
Interacting Resonance Level and observe a Fermi Edge Singularity out of equilibrium as the impurity level approaches
resonance. We then apply the approach to the quantum dot (the nonequilibrium Anderson Impurity model) and
observe the formation of the Kondo peak as the gate voltage is decreased and the peak destruction as the source-drain
voltage is increased.

String theory is a candidate for the quantum theory of gravity. Being such, it is often used a theoretical tool to study general problems in contemporary theoretical physics. This talk will focus on branes, extended objects in space time, and the gauge theory that lives on their world volume - the so called "Quiver Gauge Theory", as a toy model for the Standard Model of particle interactions. Conformal Field Theories (CFT) are of interest in various areas of theoretical physics, and are most notably known for their applications to critical phenomena in 1+1 or perhaps 2 dimensions. This talk describes an original work of my research group, which was developed over a period of about a dozen years, that deals with periodic tilings of the two dimensional plane and discusses how they turn out to play a crucial role in the formulation and solution of the largest known class of Super CFT's (SCFT) in 3+1 and 2+1 dimensions. Methods from the study of "dimers", objects typically used in statistical mechanical systems and in combinatorics, are used to solve for the exact spectrum of the above mentioned SCFT's and provide a deep link with string theory and topics in pure mathematics such as algebraic geometry, shedding a new light on the study of Calabi-Yau singularities in 3 and 4 complex dimensions.

By focusing on long-term changes in societal interactions with one slice of nature--the nitrogen cycle--the "Story of N" provides a unique view of industrial society learning to interact with a complex earth system in a more sustainable fashion. Two centuries ago, flows of chemically active nitrogen through the biosphere differed significantly from the flows that exist today. Since then, humans have bypassed limits previously imposed by nitrogen-fixing bacteria and have roughly doubled the amount of chemically active nitrogen created each year. Our response to the resulting build-up of nitrogenous compounds and the associated concerns--including photochemical smog, hypoxic dead zones, nitrates in groundwater, acid rain, ozone depletion, and even climate change--suggests that learning to establish and manage ecological budgets is a key step on the road to sustainability.

We will continue last week's discussion on research topics in Physics Education both here at Minnesota and at other institutions, including an overview of current "hot topics" in the field.

The South Pole Telescope (SPT) is a 10-meter telescope optimized to study of dark-energy and inflation through arcminute resolution maps of the cosmic microwave background (CMB). Construction and commissioning were completed in January 2007, and since then we have acquired two years of data. Using these observations we recently published the first detection of galaxy clusters selected with the Sunyaev-Zel'dovich (SZ) effect. Through the SZ effect, we will detect a large number of clusters and trace the evolution of dark energy through its effect on the growth of large scale structure. In addition, the survey data will provide an improved measurement of the temperature power spectrum of the CMB up to arcminute scales which will
improve constraints on the power spectral index of primordial scalar perturbations. In this talk I provide an overview of the SPT instrument and discuss the prospects for cosmology.

First I will make a general introduction to neutrino physics, with emphasis in neutrino oscillation physics. Then I will review in detail the current status and results of the MINOS experiment, as well as its future prospects. At the last part of the talk I will focus on the remaining, challenging open questions related with neutrinos, and I will discuss how we plan to address them with near term, NOvA, as well as longer term, FNAL-TO-DUSEL long baseline neutrino oscillation experiments.

I present a nontechnical review of current understanding of the phenomenon of color confinement: from the conceptual roots of the idea related to Abrikosov vortices in superconductors to modern implementations of the dual Meissner effect in non-Abelian theories similar to quantum chromodynamics, the theory of hadrons. Supersymmetry was instrumental in recent developments. Efforts aimed at solving various aspects of QCD basing on supersymmetry and string-inspired ideas bring fruits. In a remarkable entanglement, theoretical constructions of the 1970s and 1990s combine with today's ideas to provide new insights.

Weakly interacting massive particles can annihilate and provide an important
heat source for the first stars to form in the Universe. The first phase of
stellar evolution may be Dark Stars, powered by dark matter heating rather
than fusion. This talk presents the story of these Dark Stars: how they
form, how long they might live, and what they might become at the end of
their life.

Electronic properties in strongly correlated systems often reveal strikingly enhanced features compared with those in conventional materials. Examples are the high transition temperature in cuprate superconductors and the colossal magnetoresistance in manganites. The layered triangular lattice cobaltates Na_x CoO_2 exhibit several interesting electronic phases such as superconductivity, charge ordering and high thermopower, as the Na content is varied. In this talk I will describe our experimental progress in the high Na doping range characterized by even steeper enhancement of thermopower, which makes this material a strong candidate for low temperature thermoelectric applications. Tim permitting, I will present recent data showing dramatic changes in transport upon very small variations in Na content, and discuss these findings in relation to a recent discovery of periodic Na ordering.

Instructors often wonder whether there is a diagnostic test or some other information that can be used to determine a student’s readiness for introductory college physics. To investigate this, we examine the correlation of pre-test scores from both the Force Concept Inventory and a Mathematics Skills Test with grades in introductory physics courses. Data is analyzed separately for males and females to test for gender differences in the predictive power of these diagnostic exams.

Cool, luminous stars such as M supergiants and AGB stars can tell us about the star formation history and chemical evolution of the central 100 pc of our Galaxy. Is star formation skewed towards massive stars in the Galactic Center? Where does the gas currently fueling star formation in the Galactic
Center come from? Can we detect the earliest phases of star formation in the Galactic Center? Infrared spectroscopy and imaging on Gemini-S and Spitzer help to answer these questions.

An unappreciated feature of nineteenth-century mesmerism is its role stimulating ideas about social relations and group behavior. Central to these developments is the rise of interest in sympathy. Nineteenth-century Americans made it one of their most resonant sentiments and imbued it with social agency. The prevailing view that a mesmerist could be put in sympathetic communication with entranced persons and thereby manipulate their bodies and minds raised troubling questions about the social vulnerability of people. This presentation will examine both the differentiation and development of sympathy as a social emotion and the mesmeric practices and theories addressing social vulnerability. Of particular interest is the mesmerist LaRoy Sunderland (1804-1885), who wove sympathy and mesmeric social phenomena into a psychological theory of urban crowd behavior, religious "manias" and social contagions (such as investment scheme crazes). As such, the study of mesmerism provides insights into the history of emotions and social psychology.

Noble liquid detectors are changing in a fundamental way the field of direct dark matter searches. They feature excellent discrimination between minimum ionizing events - due to background radioactivity - and nuclear recoils - the signature of WIMP dark matter interactions. Their unmatched promise of a rapid scaling of the target mass (by 2-3 orders of magnitude!) and of a corresponding increase in sensitivity is driving a large number of researchers into the field: it's the 21st century gold rush of astroparticle physics. Will they provide the first successful exploration of the dark sector? Finally, I will present very recent results from the Borexino solar neutrino experiment. I will also discuss how the technology developed in the context of solar neutrino searches will impact future direct dark matter searches.

The mechanism of electroweak symmetry breaking lies at the heart of the fundamental questions of contemporary physics. While many theories consider different scenarios for this mechanism, experimental evidence on its detailed workings is still to be found. This talk details some the studies performed at the Tevatron, currently the highest-energy hadron collider in the world, in the quest to find experimental evidence on this mechanism.

The non-perturbative dynamics of non-supersymmetric QCD-like and especially chiral gauge theories remained largely elusive despite much effort over the years. Recently, novel analytical techniques (such as deformations and non-thermal compactifications) which allow us to gain very detailed and at the same time intuitive understanding of gauge theories are developed. In certain cases, confinement and mass gap generation for gauge fluctuations can be understood by using abelian duality as in the supersymmetric examples. The types of topological excitations that appear on a cylinder are far richer than anticipated earlier. For example, a newly found composite referred to as magnetic bion with net magnetic charge +2 is responsible for the appearance of a mass gap in most QCD-like and chiral theories. What makes this excitation interesting is also an exotic mechanism of pairing, induced by fermion pair-exchange. Some of these techniques may find useful applications in two dimensional frustrated spin-systems (such as in Kagome antiferromagnets). In this talk, I will give a non-technical conceptual overview to these recent progresses.

We have constructed an instrument that records a complete time-domain laser fluorescence decay, resolved on the subnanosecond time scale, 10000 times per second, with high S/N and reproducibility. We are using this instrument to measure intramolecular and intermolecular distances in muscle proteins during their biochemical activities. This is accomplished by time-resolved fluorescence resonance energy transfer (TR-FRET), which can determine complex distance interprobe distributions in the range from 2 to 8 nm. When this experiment is performed following the rapid mixing of proteins and substrates, we record these signals resolved on the millisecond time scale of biochemical kinetics. This new experiment, called transient time-resolved FRET, (TR)2FRET, provides multidimensional structural information on the time scale of biochemical reactions. We have used it to define the internal structural dynamics of two muscle proteins during their ATP-driven energy transduction processes: myosin, which generates force in contraction, and the calcium pump, which relaxes muscle by removing calcium after a contraction. These studies are being used to determine how the molecular machine works, how it fails in disease, and how to repair it therapeutically.

Fermilab's Tevatron collider experiments (DZero and CDF) have devoted major efforts to find the elusive Higgs boson. Together, their results are just beginning to reach the level required to exclude potential Higgs boson masses. My presentation will cover the details of the Tevatron's road to the Higgs, including the recent Higgs mass exclusion of mH=170 GeV. I will also discuss the Tevatron's newest landmark in the Higgs search: the first evidence for semileptonic diboson decays (WW/WZ->lvjj) at a hadron collider.

I will present two examples of roles that theorists play during the dawn of the new experimental renaissance in high energy physics. The first will be based on model building and making predictions for the LHC. The second example will focus on the recent PAMELA/ATIC experimental anomalies and the role that theorists can play once data is released.

Darwin believed that his theory of evolution would stand or fall on its ability to account for human behavior. No species could be an exception to his theory without imperiling the whole edifice. One of the most striking features of human behavior is our very elaborate social life involving cooperation with large numbers of other people. The evolution of the ethical sensibilities and institutions of humans was thus one of his central concerns. Darwin made four main arguments regarding human morality: (1) that it is a product of group selection; (2) that an immense difference existed between human moral systems and those of other animals; (3) that the human social instincts were "primeval" and essentially the same in all modern humans; and (4) that moral progress was possible based on using the instinct of sympathy as the basis for inventing and favoring the spread of improved social institutions. Modern studies of cultural evolution suggest that Darwin's arguments about the evolution of morality are largely correct in their essentials.

Sponsored by the Minnesota Center for Philosophy of Science.

Problem solving is a complex skill that is important for learning physics. Unfortunately, there is no standard way to evaluate problem solving. An assessment tool commonly used for complex processes such as problem solving is a rubric, which divides a skill into multiple categories and defines criteria met to attain a score in each. Such rubrics are often difficult and time-consuming to use. I will report progress on the development of a general physics problem-solving rubric and give examples of the its application to student solutions from a calculus-based introductory physics course for science and engineering students. I will also examine the rubric's usefulness for different types of problems and solutions that span the multiple physics topics within a first-semester course.

The direct detection of gravitational waves will provide a
revolutionary new probe of the most energetic processes in the
universe. The 4 km long LIGO interferometers have demonstrated the sub-attometer displacement sensitivity (< 10^{-18} m/ Hz^{1/2}) required to place upper limits on the neutron star/neutron star merger out to the Virgo galaxy cluster. Such mergers are thought to be the progenitors of short gamma-ray bursts and provide an ideal "golden event" signal for direct GW detection. Compact binary coalescences also offer one of direct tests of the neutron star equation of state, of the internal dynamics of supernovae, and of strong field general relativity.
An aggressive R&D program, Advanced LIGO, is underway to increase the interferometer stored power 30-fold (to 750 kW), develop new low noise readouts, and increase the detector sensitivity by an order of magnitude.In the next 5 years, Advanced LIGO will observe neutron star mergers and other gravitational wave events regularly, beginning a new era of gravitational astronomy.

I will discuss a model of supersymmetry breaking in which supersymmetry is spontaneously broken in a strongly coupled hidden sector and transmitted to the Standard Model via semi-direct gauge mediation. This model is calculable via the gauge/gravity correspondence. The gravity dual is a background where supersymmetry is broken at the end of a warped throat, and then transmitted to the Standard Model via gauginos living in the bulk. The leading effect arises from the splitting of "messenger mesons", which are Kaluza-Klein modes on the D-branes supporting the Standard Model.

This model illustrates some applications of String Theory D-branes: engineering quantum field theories, understanding their (non-perturbative) dynamics and providing a tool for performing calculations at strong coupling via the gauge/gravity correspondence.

The Compact Muon Solenoid (CMS) Experiment is a general purpose particle detector experiment at the Large Hadron Collider (LHC)at CERN. The CMS detector is instrumented with a high precision, high granularity electromagnetic crystal calorimeter, which will allow for a wide range of physics studies with photons. Such studies include the search for the Higgs boson in the di-photon decay channel, as well as the quest for new physics beyond the Standard Model. In my talk I will describe the plans for CMS physics analyses with photons, also highlighting the use of photons as an important diagnostic and calibration tool in the LHC start-up phase.

The nature and identity of the dark matter of the Universe is one of the most challenging problems facing modern cosmology.
Supersymmetry offers a natural candidate for dark matter.
After a brief review of the evidence for dark matter, I will discuss the phenomenological consequences for supersymmetry both in the context of dark matter and upcoming experiments at the LHC.

A variety of condensed matter and cold atomic systems involving bosons on lattices exhibit the fascinating phenomenon of coexistent quantum states of matter. The presence of inhomogeneities in these systems can cause some regions to display superfluidity and others to display insulating behavior. This talk will discuss the basic physics underlying such coexistence, means of probing superfluid regions trapped between insulating regions, the collective properties of these trapped regions and the possibility of Josephson physics in these systems.

Hydrogen and helium accreted on a neutron star can undergo unstablethermonuclear burning, which is observable as a flash of X-rays. When fuel is accreted continuously, X-ray bursts occur with recurrence times of hours or days. We discuss what determines this timescale and show the puzzling observations of bursts with recurrence times of only minutes. Hydrogen and helium flashes build up a carbon-rich layer that extends down to the neutron star crust. When this layer burns in a flash, a so-called superburst can be observed. These are much rarer events than ordinary bursts. We place constraints on the superburst recurrence time of nine sources and show how they can be used to constrain models of the neutron star interior.

Large-scale structure has long been known to encode basic information about our universe. For example, the formation of the largest collapsed objects, clusters of galaxies, and the fraction of their mass in baryons constrain dark energy, the matter density, and the amplitude of matter fluctuations in the Universe. Clusters have a bright future as a probe of cosmology with several large, multiwavelength surveys ongoing or planned. However, to fully utilize the power of clusters as cosmological probes, we must improve our understanding of and our control of systematics in cluster observations, particularly with respect to deviations from equilibrium associated to cluster-cluster mergers. Using both observations and cosmological, hydrodynamic simulations, I show how we can quantify the frequency and importance of cluster mergers and how we can calibrate for their corresponding effects in cosmological studies. In addition, the recent launch of the Fermi Gamma-ray Space Telescope has opened an entirely new observational window on clusters. Gamma-ray emission related to shock-accelerated cosmic rays will further illuminate the violent merger past of clusters, and gamma-ray observations may even reveal light from dark matter annihilation.

Early-type stars lose mass throughout their lives via radiation-driven winds. These outflows are understood to be important agents of change because they alter (a) the evolutionary trajectory of an individual star through the H-R diagram; and (b) the evolution of their local interstellar environments through the deposition of energy, momentum, and chemically
enriched material. Consequently, hot-star winds are important ingredients in many astrophysical contexts. But how well do we know the mass loss carried by the wind of an O-type star?

In this talk, I will review the different techniques used to measure the mass-loss rates of early-type stars, and will describe the current state of confusion that results from the markedly different estimates provided by two "blue-ribbon" diagnostics. I'll discuss the likely resolution of this
mass-loss discrepancy; its implications for our understanding of the structure of hot-star winds; and how these new insights help (or hinder?) our understanding of other astrophysical problems.

Since the mid-1960s, researchers in computer science have famously referred to chess as the "drosophila" of artificial intelligence. What they seem to mean by this is that chess, like the common fruit fly, is an accessible, familiar, and relatively simple experimental technology that nonetheless can be productively used to produce valid knowledge about other, more complex systems. But for historians of science and technology, the analogy between chess and drosophilia assumes a larger significance. As Robert Kohler has ably described, the decision to adopt drosophila as the organism of choice for genetics research had far-reaching implications for the development of 20th century biology. In a similar manner, the decision to focus on chess as the measure of both human and computer intelligence had important and unintended consequences for artificial intelligence research. This paper explores the emergence of chess as an experimental technology, its significance in the developing moral economy of the AI community, and the unique ways in which the decision to focus on chess shaped the program of AI research in the decade of the 1970s. More broadly, it attempts to open up the virtual black box of computer software -- and of computer games in particular -- to the scrutiny of historical and sociological analysis.

The Modeling Instruction Program at Arizona State University
(http://modeling.asu.edu) has been rated as one of the top programs for research-based reform to K-12 science education. What is "Modeling" all about? What does it look like in the classroom? Dave will share his insights about the ASU program and describe how he uses Modeling Instruction in his high school physics classes.

Viewed at very high energies, the universe is a place of powerful astrophysical engines driving accelerators that reach far greater energies than anything built on earth. By studying the products of these accelerators (such as cosmic rays and gamma-rays), we can not only learn a great deal about the astrophysics of these sources, but probe a variety of questions in particle physics and cosmology. A new generation of imaging atmospheric Cherenkov telescopes (IACTs),designed to detect VHE (100 GeV-10 TeV) gamma-rays, has radically altered our picture of the very high-energy gamma-ray sky. One such instrument is the recently-commissioned IACT array VERITAS, which saw first light in April 2007. I will discuss results from the first two years of the VERITAS observing program and the guidance that they offer for the next few years of the VERITAS program. The impact of (and synergy with) the recently-launched Fermi satellite, which promises to similarly revolutionize gamma-ray astronomy in the 20 MeV to 300 GeV band, will also be discussed, along with long-term directions for the field.

In the Standard Model, quark mass, their mixing and CP violation
have a common origin, the spontaneous electroweak symmetry breaking due to the Higgs boson. Studying CP violation and flavor-changing interactions not only probes the electroweak scale, but also provides an excellent laboratory for us to search new physics beyond the Standard Model. In this talk, I will present the most recent measurements of CP violation in the B meson decays from Babar experiment. The main focus of the talk will be the determination of the Cabibbo-Kobayashi-Maskawa (CKM) phase: beta. I will also discuss the implication of the results of CP violation in B decays for the Standard Model and some of its extension.

Can we learn about New Physics with astronomical and
astro-particle data? Understanding how this is possible is key to
unraveling one of the most pressing mysteries at the interface of
cosmology and particle physics: the fundamental nature of dark matter. Rapid progress may be within grasp in the context of an approach which combines information from high-energy particle physics with cosmic-ray and traditional astronomical data. I discuss recent puzzling data on cosmic-ray electrons and positrons and their interpretation. I show how the Fermi Space Telescope will soon shed light on those data as well as
potentially on several dark matter particle properties. I then introduce a novel approach to particle dark matter searches based on the complementarity of astronomical observations across the electromagnetic spectrum, from radio to X-ray and to gamma-ray frequencies.

In the BCS paradigm for the superconducting state, electrons close to the Fermi level E_F form Cooper pairs which condense into a zero center of mass momentum state. This results in a gap in the electronic excitation spectrum that is symmetrically
centered about E_F . Above T_c where the condensate is lost, the pairs dissociate, the energy gap collapses, and the normal state Fermi surface appears. On the other hand,in the underdoped high temperature superconductors, instead of a complete Fermi
surface above T_c , only disconnected regions of the Fermi surface appear, separated by regions that still exhibit an energy (pseudo)gap. After introducing the technique of angle resolved photoemission, used to study the electronic excitations in materials, we show that in this pseudogap phase, the energy-momentum relation of electronic excitations near E_F behave as they do in a normal metal in regions with a Fermi surface, but like that of a superconductor in the gapped regions. We discuss these results in terms of competing order parameters, and the relationship between pairing and condensation

I will describe the measurements of asymmetric conductance and the current shot noise through a carbon nanotube quantum dot with one ferromagnetic and one normal-metal lead. The observed asymmetry is spin-dependent, and stems from the interplay between the spin accumulation and the Coulomb blockade on the quantum dot. The results imply that the current is spin-polarized for one direction of the bias, and that the degree of spin polarization is fully and precisely tunable using the gate and bias voltages. As the operation of this spin diode does not require magnetic fields or optics, it could be used as a building block for electrically controlled spintronic devices.

Modern cosmology is at once glorious and absurd - detailed measurements of various types all fit the now standard LCDM cosmological model, but this model demands that ordinary matter is sub-dominant to mysterious dark matter, and even more mysterious dark energy. This last is particularly troubling because it implies that the expansion of the Universe is accelerating, and will continue to do so forever! One of the main pillars of the standard cosmology is observations of the cosmic microwave background (CMB). After reviewing what
the CMB is and how it tells us about the Universe I will focus on a series of experiments conducted over the last ten years at the South Pole in Antarctica, and the push to the final frontier of CMB research --- the search for the polarized imprint of gravitational waves spawned in the first instant of creation.

Debris disks are dust disks produced by pulverizing sub-planetary
objects, such as asteroids, KBOs, and comets. Debris disks can be detected through IR excess, and because of their larger surface areas they are easier than planets to detect. For stars similar to the Sun, spectral types of F to K, Spitzer MIPS 24 and 70 micron observations can probe debris disks at locations of Asteroid Belt and Kuiper Belt, respectively. As a star evolve to its final state of white dwarf (WD), a significant fraction of the stellar mass has been ejected to form a planetary nebula, which is not gravitationally bound to the star and its planetary system. It is conceivable that a planetary system would dynamically evolve along the late stellar evolution. Debris disks have been detected around cool WDs (~10,000 K) at distances <<0.01 AU; their locations within the Roche limit and the enhanced metal abundances in the WD
atmospheres both point to an origin of tidally disrupted asteroids. A different type of debris disk is recently detected around the central hot WD (110,000 K) of the Helix Nebula. Spitzer MIPS observations revealed bright emission from this hot WD at 24 and 70 microns. This IR excess has been suggested to originate from a debris disk produced by collisions among KBOs. If true, the high temperatures of hot WDs, >100,000 K, provide a unique opportunity to take a last glimpse at the outer planetary system of a star. We have made a Spitzer MIPS 24 micron survey of 73 hot WDs and made follow-up IRS observations to probe the nature of the detected IR excesses. The results will be discussed.

During his lifetime, Herman Boerhaave gained a reputation as a great teacher, systematizer, and promoter of empiricism in medicine and chemistry. He was also an avid practitioner of alchemy. Boerhaave's extant papers include notes from hundreds of hours of alchemical experimentation performed periodically over forty years (c. 1696-1737). Among these records are included numerous attempts to induce metallic transmutation by various means and several tries to fabricate "philosophical" mercury, a necessary step in some recipes for the Philosophers' Stone. Yet, Boerhaave was not a naive believer in the power of alchemy. What began as an interest driven by curiosity and faith became a research program for the testing of alchemical claims, culminating in a series of papers published in the Philosophical Transactions. In his "De Mercurio experimenta" (1733-6), Boerhaave praised the alchemists for their "tenacious work," condemned them for their obscurity and secrecy, and set about to scrutinize their claims "for all to see." In this talk, I will examine the origins and execution of Boerhaave's program for testing alchemical claims, especially within the context of his philosophical and pedagogical view of chemistry as a whole. I will argue that Boerhaave rejected many alchemical claims simply by treating them like any other empirical claim in his chemical system (rather then privileging their factual status by relying on witness testimony or philosophical argument). Ultimately, this paper will contribute to an understanding of the complex relationship between alchemy, chemistry, and natural philosophy in the early Eighteenth Century.

Sponsored by Program in the History of Medicine.

A recent study published in Science and featured on NPR’s Science Friday radio program reported that Chinese students outperform U.S. students on tests of physics content knowledge, but both groups perform equally on a test of scientific reasoning skills. As a group we will discuss the study’s findings, differences in the China and U.S. education systems, and the implications of this study for science education.

Gravitational-waves are thought to be emitted by a wide variety of sources both astrophysical and cosmological in origin. While it is possible to identify individual nearby sources such as galactic pulsars or neutron-star/black-hole coalescences, other sources--each individually unresolvable--will conspire to produce a stochastic background. The angular distribution of the stochastic background is not easily predicted, and so we are faced with a challenge: stochastic searches should be flexible enough to accommodate a wide variety of distributions, but in doing so, they must not introduce so many parameters as to hamper the sensitivity of the search. In this talk I will present an algorithm that addresses the issue of how to detect an anisotropic stochastic background with little prior information about the nature of the anisotropy.

The year just finished witnessed the first beams of particles circulated in a new accelerator near Geneva, Switzerland -- the Large Hadron Collider (LHC). The event received remarkable media attention as well as intense scientific interest. This colloquium will discuss the physics goals of the collider, the experience of first beam, the subsequent failure of a portion of the machine, and the outlook for the near future both in the operation of the collider and the physics results to be expected.

There is now a large database on high-resolution observations of elemental abundances in old stars that reside in the halo of our Galaxy. This represents an exquisite record of chemical evolution of the early universe and has important implications for the stellar sources producing the various elements. The observational data will be reviewed, as well as the current stellar models for nucleosynthesis. It will be shown that three different types of massive stellar sources are required to explain the data. In particular, hypernovae with large explosion energies and Fe yields are an important player.

bstract: The converted 6.5m MMT Observatory has a powerful suite of new instrumentation accumulated over the last eight years. Instruments for all four configurations of the telescope such as the facility Red and Blue Channel spectrographs (R = 240 – 6600) and the visiting spectropolarimeter (SPOL) used with the f/9 secondary. Instruments using the f/5 spectroscopic configuration, the bench mounted 300-fiber spectrographs Hectospec (R=1000) and Hectochelle (R=30,000), and the single slit, cross-dispersed spectrograph MAESTRO (R=28,000 – 93,000). The f/5 imaging configuration offers Megacam, a 24' x 24' CCD mosaic camera and SWIRC, a YJH NIR imager. The MMT's pioneering f/15 adaptive secondary mirror enables high-resolution imaging and spectroscopy in the infrared with the ARIES, CLIO, PISCES and BLINC/MIRAC instruments. The AO system will shortly be significantly enhanced with the addition of a Rayleigh laser guide star system which is currently being commissioned. Upcoming instrumentation will include slit mask spectrographs in the infrared (MMIRS) and optical (BINOSPEC), and a polarimeter (MMTPol). This review talk presents all the current and future instruments capabilities, gives some recent science results and demonstrates how the observatory has become highly efficient at managing multiple secondary mirrors and a large instrument suite.

An introductory review of the foundations of the Attractor Mechanism in
extremal black holes in d=4 (ungauged) supergravity theories will be
given.
The issues of the classification of black hole attractors, of their
stability and of the definition of an effective potential in the scalar
manifold will be addressed.
Finally, some recent developments will be shortly considered, such as the
charge orbits and the moduli spaces of attractor solutions in N=2 and
extended supergravities, and the generalization of the Attractor Mechanism
to intersecting configurations of black branes in higher dimensions.

At present, the (quasi-)equilibrium structure of self-gravitating,
cold, collisionless material (a.k.a. dark matter) is studied using
N-body simulations, which give us the dynamical properties of DM
halos, like the radial density profile. However, the physics behind
this, i.e. the physics of collisionless relaxation is not fully
understood. I'll describe the recent progress in this field.

On December 11, 2008, the U.S. Department of Energy (DOE) announced “that Michigan State University (MSU) in East Lansing, MI has been selected to design and establish the Facility for Rare Isotope Beams (FRIB), a cutting-edge research facility to advance understanding of rare nuclear isotopes and the evolution of the cosmos.” In this talk I will provide a high-level summary of the envisioned science program, the facility layout and user interfaces for the planned facility. In addition, I will highlight existing and newly emerging rare isotope research opportunities for future FRIB users who can initiate or participate in cutting edge rare isotope research programs at the existing NSCL, which can seamlessly transition to FRIB.

Hydrogen and helium accreted on a neutron star can undergo unstable thermonuclear burning, which is observable as a flash of X-rays. When fuel is accreted continuously, X-ray bursts occur with recurrence times of hours or days. We discuss what determines this timescale and show the puzzling observations of bursts with recurrence times of only minutes. Hydrogen and helium burning builds up a carbon-rich layer that extends down to the neutron star crust. When this layer burns in a flash, a so-called superburst can be observed. These are much rarer events than ordinary bursts. We place constraints on the superburst recurrence time of nine sources and show how they can be used to constrain models of the neutron star interior.

The standard account of the two-slit experiment is presented, and that is followed by a careful examination of some of the key assumptions involved in the account. Logical, metaphysical, and probabilistic assumptions are revealed and then called into question. The standard logic of the experiment presupposes a particle model, and that leads to paradoxical probabilistic consequences. An alternative logical structure is proposed for the experiment; it is based on a wave model. That logical structure leads to a non-standard theory of probability that has distinct advantages, including the ability to give a coherent account of the two-slit experiment. That account explicitly involves a distinction between actual and virtual chances, which may have important interpretive consequences for the quantum realm and more broadly including such areas as economics, queuing theory, and psychology.

Sponsored by the Minnesota Center for Philosophy of Science.

The PhysTEC Program at the U of M is finishing its second year. We will discuss how the program has changed and grown during this time and will also consider what the future may hold for PhysTEC. A key component of this program has been the use of Learning Assistants (LAs). Their roles will be defined and discussed as well. Prior to the seminar, interested participants may want to read the feature article on PhysTEC in the February 2009 issue of "Physics Today". It can be found at: here

The WMAP team has recently published the results of five full years of observing the centimeter-wavelength sky (from 23 GHz to 93 GHz). In addition to cosmological information, the data provide a unique window into the behavior of three Galactic processes: synchrotron radiation, free-free emission from ionized hydrogen, and thermal dust radiation. I will present a new estimate of foreground emission in the WMAP data, using a Markov chain Monte Carlo (MCMC) method, which provides maps
and error-bars for each foreground component.

The first radio surveys of the sky discovered that some large clusters of galaxies contained powerful sources of synchrotron emission. Optical images showed that the intra-cluster medium was permeated by long linear filaments with bizarre emission line spectra. Recent observations in the infrared and radio show that these filaments have very strong emission lines of molecular
hydrogen and carbon monoxide. The mass of molecular material is quite large, the gas is quite warm, and the filaments have not formed stars despite their multi-Gyr age. I will discuss the general astrophysical context of large clusters of galaxies and how large masses of molecular gas can be heated to produce what we observe.

In 17th-century France during the reign of Louis XIV, a navigational canal was built across Languedoc to join the Mediterranean Sea to the Atlantic Ocean through the Garonne River. It was called the Canal du Midi. The project was massive and at its completion hailed as a wonder of the world. But its importance lay less in its splendor than in the kind of power that it embodied. This project was part of the effort by the king’s minister, Jean-Baptiste Colbert, to undercut the autonomy of the nobility and shore up the power of the state. He could not achieve this shift in power through traditional patrimonial politics, since nobles threatened the king’s reign precisely because of the autonomy they achieved through their tight patrimonial bonds. The alternative was to change the face of the French countryside to embody the authority of the monarch over his kingdom and to empower the state by giving it land over which to exercise authority. This was the switch to impersonal rule that I want to describe in this talk, a politics exercised through engineering. The engineering knowledge required for the work importantly did not come from the state even though it stood for its powers. It was a product of distributed cognition, the combined intelligence of different groups from Pyrenean women peasants to artisans to military engineers. Together they created an anonymous intelligence that represented the state at the local level and was used to change the conditions of possibility for local life. The Canal du Midi was a prime example of this infrastructural engineering and the politics of impersonal rule. Its history reveals tight connections between early technoscientific culture and state formation in 17th-century France.

Cosponsored by the Institute for Advanced Study and Theorizing Early Modern Studies.

Kawin Chaumklang will be presenting data from his Preliminary Dissertation study on the perceptions of student-centered teaching and learning among high school Physics teachers in Thailand. Brita Nellermoe will be presenting a summary of her experience with the Teaching Internship in Thailand in the summer of 2007, where she spent 3 1/2 weeks teaching Physics at a Thai High School.

Using Very Large Baseline Interferometry, it is now possible to use parallax to measure the distances to objects in the Milky Way to very high accuracy. This work suggests the Milky Way is about 50% more massive than previously thought and also shows conclusively that the Sgr A* is a black hole.

The electron carry not only an electrical charge but also a spin. The spin can be viewed as a tiny magnet and, actually, the magnetism of matter is mainly related to the orientation of the spin of the electrons. Spintronics is a new type of electronics exploiting not only the charge of the electrons but also the influence of the spin on their mobility in magnetic materials. We are already familiar with spintronics since we use everyday the "Giant Magnetoresistance" (GMR) to read the hard disc of our computer or listen to music on our I-Pod. The discovery of the GMR, 21 years ago, kicked off the development of spintronics which is expanding today in many very promising directions. I will describe the most recent advances. The current researches will probably lead to a new type of memory (STT-RAM) for our computer, to smart radio-wave emitters for our telephone and, perhaps, to qubits for quantum computing.

The usual materials of classical spintronics are magnetic and nonmagnetic metals, magnetic and nonmagnetic semiconductors and, for tunnel junctions, insulating materials like MgO or alumina. However, nowadays, promising results begin to be obtained with a new family of materials which includes carbon nanotubes, graphene and several types of magnetic or non-magnetic molecules. The general advantage of carbon-based materials is mainly their long spin lifetime related to the small spin-orbit coupling of carbon, but, as we will see, the very high electron velocity of some of them is also of great interest for spintronics. The first part of the talk will be an introduction on classical spintronics and a review of what can be done with molecular materials for TMR, spin transport in lateral structures, magnetic switching or microwave generation by spin transfer. In the second part of the lecture I will focus on the general problem of spin transport in a nonmagnetic lateral channel between a spin-polarized source and a spin-polarized drain, a structure which is at the basis of several concepts of logic devices or spin transistors. The main difficulty is related to the transformation of the spin information – related to the magnetic configuration of the electrodes- into a large electrical signal, ideally Δ V/V ≈ 1 or larger, if V is the bias voltage and Δ V some voltage variation induced by a change of the magnetic configuration. In experiments on structures in which the lateral channel is a metal or a semiconductor, Δ V/V does not exceed a few 1% and the electrical signal Δ V is generally in the μ V range. In contrast, in the experiments on carbon nanotubes between ferromagnetic contacts we will present, high values of Δ V/V ( above 70%) and large Δ V (of the order of 100 mV) can be obtained. After a description of the theoretical background, we will discuss the origin of the difficulties for semiconductors and explain why large values of Δ V/V and Δ V can be easily obtained with carbon nanotubes. We will emphasize the potential of carbon nanotubes, graphene and other molecules for spintronics, and conclude by presenting some next challenges for molecular spintronics.

The common wisdom suggests that simple small field models of inflation share similar properties such as red spectral index, undetectable gravitational waves (GW), undetectable running of the spectral index and undetectable non-gaussianity. In this talk I will explain the reasons for these properties and show that all of them are due to oversimplification of the models. I will demonstrate how one can design small single field models which cover all the parameter space allowed by WMAP5, for example, a small field model with detectable GW of r=0.2. Moreover, these models exhibit detectable non-gaussianity of f_{NL}>5 without exiting the slow-roll regime, making them easy targets for detection.

Ethology, the biological study of behavior, emerged as a modern scientific discipline in the 20th century thanks to the efforts of the Austrian biologist Konrad Lorenz and his Dutch counterpart Niko Tinbergen. As opposed to the collaboration of the famous twosome of James Watson and Frick Crick, which lasted only a year and a half, Lorenz and Tinbergen were critically engaged with one another for roughly four decades. This lecture explores the 20th-century origins of the discipline of ethology, paying particular attention to the interaction between Lorenz and Tinbergen, how their relations were affected by their contrasting wartime allegiances, and the enduring effects their respective research practices had on their views of what ethology was and what it could become.

The human brain is a network containing a hundred billion neurons, each communicating with several thousand others. As the wiring for neuronal communication draws on limited space and energy resources, evolution had to optimize their use. This principle of minimizing wiring costs explains many features of brain architecture, including placement and shape of many neurons. However, the shape of some neurons and their synaptic properties remained unexplained. This led us to the principle of maximization of brain's ability to store information, which can be expressed as maximization of entropy. Combination of the two principles, analogous to the minimization of free energy in statistical physics, provides a systematic view of brain architecture, necessary to explain brain function.

Eu-rich EuO, of recent interest for its possible use in spintronics applications, exhibits properties similar to those of well-studied manganite systems like La2/3Ca1/3MnO3, including an insulator to metal transition associated with the onset of ferromagnetism and a large negative magnetoresistance response. Our work focuses on exploring comparisons between the EuO system and the manganites, using the binary EuO compound as a simplified laboratory with less structural complexity than the manganites. In this talk, I will describe our experimental work in the growth of Eu-rich EuO thin films and how the transport and magnetotransport properties of the films depend on the growth conditions, as well as discussing how future work can inform our understanding of the theoretical Kondo-lattice model that has been developed to describe the EuO system.

Coffee is essential to human life, but at OSU Astronomy Department, coffee is also an important contributor to science. OSU's daily coffees seeds research across boundaries, and in this talk I will discuss three new ideas I have worked on resulting from OSU's astro-ph coffee discussions. The first idea, "Protecting Life in the Milky Way: Metals Keep the GRBs Away" formulates a strong hypothesis that gamma-ray bursts can only explode if the metallicity of parent star is below about 0.1 solar. The second, "The Future is Now: the Formation of Single Low Mass White Dwarfs in the Solar Neighborhood" discusses new aspects of stellar evolution when the stellar metallicity is highly super-solar. The third, "A Survey About Nothing: Monitoring a Million Supergiants for Failed Supernovae" examines how we could verify that all massive stars do indeed explode as core-collapse supernovae.

Jed Z. Buchwald
"Isaac Newton and the History of Civilization"
Abstract: Isaac Newton, who renovated the foundations of mathematics, optics, and mechanics in the 17th century, aimed also to overturn the entire history of civilization. Convinced that the Egyptians and the Greeks had studied at the feet of the ancient Hebrews, Newton set out to prove that Solomon’s kingdom set the pattern for all organized social life. He canvassed ancient texts for words that could be pruned and transformed into supporting evidence – deploying in the process the earliest known procedures for handling discrepant data. We will see how the most sophisticated of techniques can produce error when data is massaged to fit a strongly-held conviction.

Noel M. Swerdlow
"Galileo's Theory of the Tides"

A few percent of low-mass red giant branch and asymptotic giant branch stars show surface layers with high concentrations of lithium, generated sometime after the main sequence. As lithium is readily destroyed in stellar interiors, these observations have been the focus of both observational and theoretical investigations. Necessary conditions for lithium self-enrichment are the presence of a mechanism for rapid upward transport of material from weakly hydrogen-burning layers of the star to the surface layers and a stock of 3He as raw material. The possibility that magnetic flux tubes might provide a mechanism for rapid upward transport motivated a reinvestigation of the lithium problem using the phenomenological model of ?cool bottom processing? (CBP), which provides a formal structure for investigating both downward and upward transport with distinct rates. We present a semi-analytic model of how 3He is processed into lithium in a simple conveyor-belt model of CBP, compare its consequences with the observed compositions of stellar envelopes, and compare it with numerical calculations. It is shown that the high Li stars are readily explained by this mechanism. We discuss the conditions necessary for lithium-richness and the extent to which observations of lithium may diagnose the survival of 3He during late phases of stellar evolution. Some hints appear which suggest that the Spite plateau may simply reflect "normal high Li" stars and not the remains of Big Bang 7Li.

A few percent of low-mass red giant branch and asymptotic giant branch stars show surface layers with high concentrations of lithium, generated sometime after the main sequence. As lithium is readily destroyed in stellar interiors, these observations have been the focus of both observational and theoretical investigations. Necessary conditions for lithium self-enrichment are the presence of a mechanism for rapid upward transport of material from weakly hydrogen-burning layers of the star to the surface layers and a stock of 3He as raw material. The possibility that magnetic flux tubes might provide a mechanism for rapid upward transport motivated a reinvestigation of the lithium problem using the phenomenological model of ?cool bottom processing? (CBP), which provides a formal structure for investigating both downward and upward transport with distinct rates. We present a semi-analytic model of how 3He is processed into lithium in a simple conveyor-belt model of CBP, compare its consequences with the observed compositions of stellar envelopes, and compare it with numerical calculations. It is shown that the high Li stars are readily explained by this mechanism .We discuss the conditions necessary for lithium-richness and the extent to which observations of lithium may diagnose the survival of 3He during late phases of stellar evolution. Some hints appear which suggest that the Spite plateau may simply reflect "normal high Li" stars and not the remains of BB 7Li.

In this colloquium I will present a broad overview of humanity's 100 year search for higher transition temperature, and generally more useful, superconductors. Particular emphasis will be placed on the past 20 years. The talk will start with an introduction to superconductivity (historically, phenomenological, and theoretically) and then progress through several of the key discoveries of the past one-score years. The basic conclusion is that this is a field that is still dominated by highly intuitive searches and sudden discoveries. That being said, the past decade has seen several discoveries that seem to point toward a very promising and rich phase space. The talk is intended to be a light and fluffy review of an exciting field. Mildly off color jokes about one and all will be included free of charge.

I discuss the use of gauge/gravity duality in computing hydrodynamic dispersion relations for strongly coupled plasmas. I present recent work which has extended the computation of the sound mode dispersion relation up to third order in the momentum of the perturbation. Resulting formulas for the speed of sound, bulk viscosity, as well as some second order transport coefficients are presented for a specific class of gravity duals.

Galaxy clusters have the potential to be highly accurate probes of cosmological parameters. To do this, however, one has to be able to know the evolution of the galaxy cluster mass function to a high degree of precision. This is complicated by the fact that cluster mass is rarely measured directly - rather, observables such as X-ray temperature or luminosity, or Sunyaev-Zel`dovich temperature perturbation, are measured and then converted into masses. I will discuss recent efforts to understand the effects that correctly modeling gas in cosmological simulations has on these mass estimates, which will hopefully be useful in upcoming blind galaxy clusters surveys in the radio and X-ray. I will focus specifically on contributions from the warm-hot intergalactic medium (WHIM) and non-thermal components of the intracluster medium, including cosmic rays and magnetic fields.

In The Grammar of Science (1892), Karl Pearson explained the application of Darwinian evolutionary principles to the human species: "a capable and stalwart race of white men should replace a dark-skinned tribe which can neither utilize its land for the full benefit of mankind, nor contribute its quota to the common stock of human knowledge," and later clarified, "there is cause for human satisfaction in the replacement of the aborigines throughout America and Australia by white races of far higher civilization." This is problematic because if the choice is between genocide or creationism, the correct choice is obviously creationism. It is also problematic because if Pearson was misrepresenting Darwinism (and where were you when he laid the foundations of quantitative biology? – Job 38:4) then it undermines the credibility of other generations of scientists who also claim to speak authoritatively about evolution. Accepting that creationists seek to undermine science education in America, I will discuss the failure of biology to deal adequately with them. I will suggest that an anthropological, relativistic approach may have some value in identifying and solving some of the problems raised by the persistence of creationism.

Sponsored by the Minnesota Center for Philosophy of Science

The introductory physics labs at the University of Minnesota are
cooperative problem solving labs that deal with context rich problems. Qualitative and quantitative skills are two components of problem solving. Is it possible to obtain some measurements of the qualitative skill levels of students in these labs? Do these skill levels change during a two hour
lab period? Do they change from one lab to the next over a one or two week time interval? These questions will be discussed and some preliminary data will be presented.

Graphene: the magic of electrons in flatland
Eva Y. Andrei
Rutgers University

Graphene, a one-atom thick layer of crystalline carbon possesses extraordinary electronic properties which make it a prime candidate for novel nano-electronic devices, at the same time raising the prospect to observe phenomena hitherto unseen in bench top experiments. These unusual properties are due to charge-carriers that behave like ultra-relativistic particles, also known as massless Dirac fermions. I will present scanning tunneling microscopy and transport experiments that provide access to these particles and give new insights their unique world.

The recent discovery of methods to isolate graphene has opened an arena for new physics and applications stemming from charge carriers governed by quantum-relativistic dynamics. Because of the 2-d nature of graphene the relativistic properties of its charge carriers are easily obscured by environmental disturbances such as potential fluctuations induced by insulating substrates. I will describe scanning tunneling spectroscopy1,3 and transport2,4 experiments on suspended graphene decoupled from substrate fluctuations. Our findings include direct observation of Landau levels, measurement of the Fermi velocity, and evidence for electron-phonon and electron-electron interactions. In addition we find that, in contrast to non-suspended samples, Quantum Hall plateaus associated with valley-splitting interactions appear in suspended graphene at very low fields.

1. G. Li , E.Y. Andrei - Nature Physics,3, 623 (2007)
2. X. Du, G. Li, A. Barker, E. Y. Andrei, Nature Nanotecnology 3, 491 (2008)
3. G. Li, A. Luican, E. Y. Andrei arXiv:0803.4016
4. X. Du, I. Skachko, E.Y. Andrei, PRB 77,184507 (2008)

The Local Group of galaxies presents astronomers with a unique cosmic laboratory of dark matter structure and composition. I will discuss theoretical modeling of the formation of smallest galaxies in dark matter halos, with an emphasis on dwarf satellite galaxies in the Local Group. I will argue that the enigmatic "missing satellites problem" cannot be resolved simply by counting more galaxies and that it points towards a natural soft limit on the smallest mass halo able to become a galaxy. I will also show that detailed star formation histories of the Local Group galaxies, obtained recently with the HST, are consistent with the expectations of the hierarchical formation models.

Through much of the 1950s, Philadelphia was home to a live television show, "The Big Idea," which was aired every Sunday afternoon since 1948. Some communications scholars refer to Philadelphia as the "Hollywood" of early television production, the place where people experimented with the new medium, not quite certain what shows would appeal. The creator and host of "The Big Idea," Donn Bennett, believed television could be a medium not only for education but also for other socially valuable purposes--such as promoting invention. Inventors appeared on his show with a model of their invention, demonstrating it before a panel of engineers and the viewers; the targeted television audience were investors who Bennett and the inventors hoped would help bring the invention to market. Bennett and his assistants fielded about 5000 inquiries per year from inventors; as of 1955, about 500 inventions had been marketed. Bennett's role went far beyond hosting his television show, however. He helped the inventors find model builders or patent lawyers; he helped at least one immigrant get citizenship. He also testified before Congress on matters of patent law and invention, emphasizing the need to protect and help inventors. Both through his show and his wider activities, Bennett participated in a public debate about invention, patents, and their significance to American society, a debate that took place in the context of a resurgent consumer society and great faith in corporate R&D. Sources include newspapers and magazines, family-owned materials, and government documents.

Individual perceptions of teaching and learning shape a teacher's behavior in the classroom. Accurately measuring faculty perceptions of teaching and learning is a complex, and often inaccurate, process. This seminar will discuss current methods used in studying perceptions among Physics Faculty and will include a discussion about Ms. Nellermoe's doctoral study methodology.

Among the 117 White Papers submitted to the Cosmology and Fundamental Physics panel of the Decadal Review are several discussing expectations and prospects for detecting light from the first stars, galaxies and exotic objects. I will review some of the basic physics and astrophysics questions at stake, and the kinds of new facilities and experiments people are planning to address these issues. Note that this will be distinct set of papers from those I discussed in a recent astronomy journal club.

We do not know how auroral arcs are formed, whether or not there are different types of arcs (meaning different underlying physics), and what they correspond to in the magnetosphere. Given the ubiquity of arcs and their obvious importance to processes such as the substorm, resolving the questions we have about arcs has got to be one of the key questions in space physics. In this talk I will survey recent observations that I believe will be important to our ultimate understanding of this space physical phenomena. These observations included the differences between meso-scale (~10 km) and small-scale arcs, the orientation of arcs and their longitudinal extension across many hours of local time, the fact that arcs occur polewards of the ion isotropy boundary, waves that propagate along arcs, and the fact that some arcs oscillate and others do not. I will finish with an overview of how I think these observations relate to theories of arc formation.

Near-Earth space (or GeoSpace) is a plasma environment which sits between the Earth's atmosphere and the interplanetary medium. This region is populated by plasma that originates from the solar wind as well as our atmosphere, and is host to dynamic physical processes that are interesting not only in their own right, but also as examples of processes at work in the solar corona and more distant cosmic plasma systems. Large and small-scale electrodynamics are responsible for, among other processes, the Northern and Southern Lights, also known as the Aurora Borealis. While GeoSpace is close by, it is notoriously difficult to study. It is virtually impossible to image GeoSpace directly, and even fleets of satellites flown with state-of-the-art instrumentation provide point measurements within a vast region of space. The topology of the GeoSpace environment is largely controlled by the terrestrial magnetic field. The entire region is connected along magnetic field lines to the Earth's upper atmosphere, one consequence of that connection being the aforementioned Aurora Borealis. For more than fifty years, researchers have been struggling to develop the aurora as a means of remote sensing GeoSpace dynamics, providing a crucial compliment to direct satellite observations. In this talk, I will provide a brief overview of GeoSpace and some of the big questions that space physicists are addressing. I will focus on the aurora, and how we are now using state-of-the-art auroral observations to explore some specific questions such as how small-scale dynamics such as reconnection and MHD instabilities affect the global system topology in dramatic events called magnetic substorms.

The Lick Observatory Supernova Search (LOSS) conducted with the 0.76-m Katzman Automatic Imaging Telescope (KAIT) has been by far the world's most successful search for very nearby supernovae, having discovered over 700 of them during the past decade. The search and its results will be described. LOSS supernova rates as a function of host-galaxy Hubble type will be presented. As an aside, KAIT's utility in rapidly obtaining follow-up observations of the optical afterglows of gamma-ray bursts will also be illustrated. Finally, some follow-up studies of supernovae will be described, concentrating on several objects having massive progenitors. The extremely powerful SN 2006gy is perhaps the first pair-instability SN ever observed and could be a link to the earliest stars. SN 2006jc is a peculiar Type Ib supernova that had a luminous outburst 2 years before explosion and whose progenitor was probably a Wolf-Rayet star.

Observations of very distant exploding stars (supernovae) show that the expansion of the Universe is now speeding up, rather than slowing down due to gravity as expected. Other, completely independent data strongly support this amazing conclusion. Over the largest distances, our Universe seems to be dominated by a repulsive "dark energy" --- an idea Einstein had suggested in 1917, but renounced in 1929, anecdotally as his "biggest blunder." Dark energy stretches the very fabric of space itself faster and faster with time. But the physical origin of dark energy is unknown, and is often considered to be the most important unsolved problem in physics; it probably provides clues to a unified quantum theory of gravity.

I will briefly review, in a biased way, some of the work on environment, star formation histories, physical conditions of these local dwarf starburst galaxies. I will also present more recent results from integral field spectroscopy which describe their internal kinematics.

The Physics Education Research group at the University of Minnesota is designing web-based coaches to help students develop competent problem-solving skills in an introductory physics course. Based on the cognitive apprenticeship model, the coaches provide students with individualized guidance and feedback as they practice using an expert-like problem-solving framework to solve problems. This talk will describe an ongoing effort to develop and assess these computer coaches.

This work is supported by the National Science Foundation through
DUE-0715615.

This is the public portion of Mr. Brown's PhD thesis defense.

Abstract: Semiconductor quantum dots have a number of applications, and quantum coherent manipulation of the charge or spin of electrons is one really cool one. This talk will start with an introduction into quantum dots and the physics of both the Coulomb blockade and of quantum information, give a smattering of literature results on quantum coherent manipulation of electrons in Si and GaAs dots, and then finish with some of our recent data on electrostatically-gated Si devices including honeycomb stability diagrams.

Quantum computing based on many different types of qubits has become an important field of research. A quantum computer with its entangled qubits should provide a much more efficient technique for specific tasks such as finding prime factors of large numbers and searching a non-structured data base. We are investigating the use of Josephson junctions in a SQUID configuration for these qubits. For success, the time for logic gate operations must be shorter than the coherence times. In this talk reviews of our experiments to make better junctions and to study and eliminate the sources of decoherence will be presented. Investigations of coherence times via Rabi oscillations and the Ramsey effect will be described and the reason for using a SQUID phase qubit will be discussed. A significant improvement in coherence times during this year has been obtained.

Recent results showed that neutrinos undergo flavor oscillation and have finite masses. So far, two of the three neutrino mixing angles have been measured while the last one, theta13, remains to be discovered. Current evidence shows that the theta13 is rather small. The Daya Bay neutrino experiment will measure theta13 with high precision using the electron anti-neutrinos from the reactors at the Daya Bay Nuclear Power Plant in Guangdong, China. It is currently under construction and will start data-taking in the year 2010. In this talk, I will give an overview, current status and R&D work of the experiment.

The Sudbury Neutrino Observatory (SNO) was built to study solar neutrinos. Data collection was subdivided into three phases. Phase I ran with the acrylic vessel filled with pure D2O. Phase II included about 2 Kg of NaCl to enhance the Neutral Current signal. In Phase III, the dissolved NaCl in the D2O as been removed and an array of Neutral Current Detectors (NCDs), which are 3He proportional counters, inserted. Calibration of SNO for detecting neutrons from the neutral current signal is done using various radioactive sources such as 252Cf, 24Na and AmBe.

The Time Series analysis (TSA) has been developed as an independent and complementary means for determining various experimental parameters relevant to the calibration of the detector using the 252Cf source. A model based on an analytical formula describing the waiting time distribution between detected events for a 252Cf source in SNO has been developed. This model has as input the relevant parameters; such as neutron detection efficiency, lifetime and source strength; needed to calibrate the NCDs. Presented is the use of TSA techniques in calibrating SNO for various data collection phases.

In the past few years new published data for the pion production became avialable and a number of preliminary results have been reported based on the large samples of the neutrino interactions observed by the K2K, MiniBooNE and SciBooNE experiments. The new results might help to understand the long-standing discrepancy in four-momentum transfer observed between observed charged current pion production data and existing predictions as well as the difference in observed coherent pion production due to the neutral and charged currents. Pion production as a dominant background for the quasielastic interaction in a few GeV neutrino energy range is essential for experiments measuring neutrino oscillation parameters .
I will present an overview of the recent measurements of pion production reported by K2K, MiniBooNE and SciBooNE collaborations.

The universe as understood through particle physics has an underlying structure
that interconnects mass, flavor and chirality in complex ways.
The neutrino is a fundamental fermion that is uniquely suited as a probe of this structure. I will review some of the properties of Standard Model of particle physics that we wish to better understand and will present the physics potential and status of the NOvA experiment, a detector under construction in northern Minnesota that is designed to observe the phenomenon of neutrino oscillation.

Soon after the smectic-C_alpha* phase was discovered in one antiferroelectric liquid crystal compound, the molecular arrangements within this phase were claimed to have a “devil’s staircase” structure. Our resonant x-ray diffraction (RXRD) studies yield a much simpler molecular arrangement, namely, an incommensurate nano-scale helical pitch (INHP). Different temperature dependent INHP’s have been acquired by our research team. This summer our RXRD run in the smectic-C_alpha* range of two liquid crystal mixtures yields a surprising discovery of a novel phase having a six-layer structure.

I will present a systematic study of the microwave-induced oscillations in the magnetoresistance of a 2D electron gas for mixed disorder including both short-range and long-range components. I will discuss four distinct contributions to the photoconductivity tensor and show that the photoresponse depends crucially on the relative weight of the short-range component of disorder. Depending on the properties of disorder, the theory allows us to identify the temperature range within which the photoresponse is dominated by one of the mechanisms.

I will present a systematic study of the microwave-induced oscillations in the magnetoresistance of a 2D electron gas for mixed disorder including both short-range and long-range components. I will discuss four distinct contributions to the photoconductivity tensor and show that the photoresponse depends crucially on the relative weight of the short-range component of disorder. Depending on the properties of disorder, the theory allows us to identify the temperature range within which the photoresponse is dominated by one of the mechanisms.

The University of Minnesota Neutrino Group is participating in three experiments to better understand the properties of neutrinos and, ultimately, CP violation in the lepton sector. Current conjectures relate leptonic CP violation to the matter antimatter asymmetry in the Universe, one of the major unresolved questions in 21st Century physics. The MINOS Experiment, which is currently acquiring and analyzing data, using a 735 km neutrino beam from Fermilab, near Chicago, to the University's Underground Laboratory at Soudan MN. MINOS studies the differences in the neutrino beam between the 1 kT Near Detector at Fermilab and the 5.5 kT Far Detector at Soudan. A second experiment, called NovA, will search for the appearance in the same neutrino beam of electron-type neutrinos. NOvA will have a 15 kT Far Detector at a new laboratory under construction at Ash River MN. The third experiment is currently in the conceptual design phase. It would use a new neutrino beam from Fermilab to the Homestake Mine in South Dakota. This talk will describe both the physics and the opportunities for graduate students.

UMN Neutrino Group: Professors Cronin-Hennessy, Heller, Marshak and Poling

First results from a blind survey of galaxies at 870um in the Chandra Deep Field South (CDFS) using the 12-m APEX telescope in Chile. The study offers both improved and new insight into the properties of distant submillimeter galaxies, which trace the major events of star formination throughout the volume of the visible universe.

The small temperature anisotropy and polarization of the cosmic microwave background (CMB) radiation have been the target of numerous earth-based, baloon-born and satellite missions in the last two decades. Upcoming CMB experiments, equipped with higher sensitivity and better angular resolution, will provide us with high fidelity probes of CMB polarization state and secondaries, such as Comptonization of the CMB by the intracluster plasma, the Sunyaev-Zeldovich (SZ) effect. The CMB is essentially a snapshot of the universe at recombination and carries a valuable information about a much earlier process, cosmological inflation. Secondary effects that took place billions of years later, at redshifts of a few, such as gravitational lensing of the CMB by the intervening large scale structure and the SZ effect provide us with cosmological bounds on neutrino masses and chemical potentials as well as the dark energy equation-of-state. Rotation of the CMB polarization-plane, due to non-standard coupling of the electromagnetic field to other scalar fields, 'cosmological birefringence', can be used to set limits on the axion mass and coupling to electromagnetic fields.
Finally, spectral distortions in the SZ effect can be used to constrain non-standard scalings of the CMB temperature with redshift.

Recent technological advances have made it possible to carry out deep optical surveys of a large fraction of the visible sky. Such surveys enable a diverse array of astronomical investigations including: the search for small moving objects in the solar system, studies of the assembly history of the Milky Way, the establishment of tight constraints on models of dark energy using a variety of independent techniques and the exploration of the transient sky. The Large Synoptic Survey Telescope (LSST) is the most ambitious project of this kind that has yet been proposed. With an 8.4 m primary mirror, and a 3.2 Gigapixel, 10 square degree camera, LSST will provide nearly an order of magnitude improvement in survey speed over all existing surveys, or those which are currently in development. Over its ten years of operation, LSST will survey 20,000 square degrees of the sky in six optical colors down to the 27th magnitude. At least a thousand distinct images will be acquired of every field, enabling a plethora of statistical investigations for intrinsic variability and for control of systematic uncertainties in deep imaging studies. In this talk some of the science that will be made possible by the construction of LSST, especially dark energy science, and a brief overview of the technical design and current status of the project will be given.

Cochlear implants are the first device to successfully restore neural function. They have instigated a popular but controversial revolution in the treatment of deafness, and they serve as a model for research in neuroscience and biomedical engineering. In this talk the physiology of natural hearing will be reviewed from the perspective of a physicist, and the function of cochlear implants will be described in the context of historical treatments, electrical engineering, psychophysics, clinical evaluation of efficacy and personal experience. The social implications of cochlear implantation and the future outlook for auditory prostheses will also be discussed.

About the speaker:
Ian Shipsey is a particle physicist, and a Professor of Physics at Purdue University. He has been profoundly deaf since 1989. Recently he heard the voice of his daughter for the first time, and his wife's voice for the first time in thirteen years thanks to a cochlear implant.

The colloquium will be at the level of Scientific American.

Problem solving is a complex process that is important for everyday life and crucial for learning physics. Although there is a great deal of effort to improve student problem solving throughout the educational system, there is no standard way to evaluate written problem solving that is independent of the problem features, physics topic, or problem-solving format used by a student. Typically such complex processes are assessed by using a rubric, which divides a skill into multiple aspects and defines criteria to attain a score in each. This talk describes the development of a general problem solving rubric for the purpose of assessing written solutions to physics problems and presents evidence for the validity, reliability, and utility of scores on the instrument.

The problem of inhibiting viral DNA ejection from bacteriophages by multivalent counterions, especially Mg^{+2} counterions, is studied. Experimentally, it is known that MgSO_4 salt has a strong and non-monotonic effect on the amount of DNA ejected. There exists an optimal concentration at which the least DNA is ejected from the virus. At lower or higher concentrations, more DNA is ejected from the capsid. We propose that this phenomenon is the result of DNA overcharging by Mg^{+2} multivalent counterions. As Mg^{+2} concentration increases from zero, DNA net charge changes from negative to positive. The optimal inhibition corresponds to the Mg^{+2} concentration where DNA is neutral. At lower/higher concentrations, DNA genome is charged. It prefers to be in solution to lower its electrostatic self-energy, which consequently leads to an increase in DNA ejection. Our theory fits experimental data well. The strength of DNA - DNA short range attraction, mediated by Mg^{+2} , is found to be - 0.003 k_BT per nucleotide base. Results from expanded ensemble Monte-Carlo simulation of hexagonal DNA bundles are discussed and are shown to be in good agreement with theoretical results.

We explore the role played by the Coulomb interaction between the brush of positive N-terminal tails rooted at the inner surface of the capsid and the negative ss RNA molecule. In the first part of the talk we show that viruses are most stable when the total length of ss RNA is close to the total length of the tails. For such a structure the absolute value of total (negative) charge of ss RNA is approximately twice larger than the charge of the capsid. This conclusion agrees with available structural data.

The second part of the talk deals with the role of the strong Coulomb protein-RNA interaction in the kinetics of the virus elf-assembly. Capsid proteins stick to unassembled chain of ss RNA (which we call "antenna") and slide on it towards the self-assembly site. We show that due to such one-dimensional diffusion in an excess of proteins the virus self-assembly is more than ten times faster than the case involving only three-dimensional diffusion. In an excess of RNA the protein –RNA attraction leads to the opposite effect of kinetic trapping and slows down the assembly. We propose several experiments which are able to verify the predicted role of RNA antenna.

The role of interstellar magnetic fields in the process of stellar birth is at present very unclear. Observationally, one of the key goals is to determine the strength of the large-scale magnetic fields of giant molecular clouds. This is being addressed via Zeeman measurements of molecular lines as well as submillimeter polarimetric observations that probe magnetically aligned dust grains. For the latter technique, the main idea is to use the degree of order/disorder in the field as an indicator of the field strength, as was done for the diffuse Galactic field by Chandrasekhar and Fermi in 1953. I will review the current status of research on GMC fields and prospects for major advances with upcoming stratospheric observations.

Engineering is a philosophically inadequate profession. This is not to claim that engineering is inadequate insofar as engineers fail to do philosophy. Such a claim might be true but trivial. Why should engineers be philosophers? Instead, the argument is that engineering is caught in a fundamental difficulty that is revealed by philosophical inquiry and thus may be described as philosophical in character. Reflective or critical analysis of engineering reveals that the profession is committed to an end (public safety, health, and welfare) that is not in fact integral to it. This philosophical inadequacy or deficiency leads to misunderstandings and false expectations both within and without the profession.

We discuss the observational constraints on dynamical dark energy in the early Universe and the cosmological implications of its coupling to matter.

All seismic isolation systems developed for Gravitational Waves
Interferometric Detectors, such as LIGO, VIRGO, and TAMA, make use of Maraging steel blades. The dissipation properties of these blades have been studied at low frequencies, by using a Geometric Anti Spring (GAS) filter, which allowed the exploration of resonant frequencies below 100 mHz. At this frequency an anomalous transfer function was observed in GAS filter. Static hysteresis was observed as well. These were the first of several motivation for this work. The many unexpected effects observed and measured are explainable by the collective movement of dislocations inside the material, described with the
statistic of the Self Organized Criticality (SOC). At low frequencies, below 200 mHz, the dissipation mechanism can temporarily subtract elasticity from the system, even leading to sudden collapse. While the Young's modulus is weaker, excess dissipation is observed. At higher frequencies the appliedstress is probably too fast to allow the full growth of dislocation avalanches, and less losses are observed, thus explaining the higher Q-factor in this frequency range. The domino effect that leads to the release of entangled dislocations allows the understanding of the random walk of the VIRGO and TAMA IPs, the
anomalous GAS filter transfer function as well as the loss of predictability of the ringdown decay in the LIGO-SAS IPs. The processes observed imply a new noise mechanism at low frequency, much larger and in addition of thermal noise.

The BEPC-II accelerator is a two ring e+e- collider in Beijing, China. The collider's energy is tuned for the charm threshold region. First collisions were observed by the BES-III detector in July of 2008. These data will be used to test predictions of Lattice QCD, extract CKM matrix elements and search for exotic hadron states with gluonic content. I will describe the accelerator, detector and the physics goals of the experiment.

Can dark matter be stabilized by charge conservation, just as the electron is in the standard model? We examine the possibility that dark matter is hidden, that is, neutral under all standard model gauge interactions, but charged under an exact U(1) gauge symmetry of the hidden sector. Such candidates are predicted in WIMPless models, supersymmetric models in which hidden dark matter has the desired thermal relic density for a wide range of masses. Hidden charged dark matter has many novel properties not shared by neutral dark matter: (1) bound state formation and Sommerfeld-enhanced annihilation after chemical freeze out may reduce its relic density, (2) similar effects greatly enhance dark matter annihilation in protohalos at redshifts of z ~ 30, (3) Compton scattering off hidden photons delays kinetic decoupling, suppressing small scale structure, and (4) Rutherford scattering makes such dark matter self-interacting and collisional, potentially impacting properties of the Bullet Cluster and the observed morphology of galactic halos. We analyze all of these effects in a WIMPless model. We find that charged hidden dark matter is viable and consistent with the correct relic density for reasonable model parameters. At the same time, in the preferred range of parameters, this model predicts cores in the dark matter halos of small galaxies and other halo properties that may be within the reach of future observations. These models therefore provide a viable and well-motivated framework for collisional dark matter.

Metamaterials are artificially engineered structures that have properties, such as negative refractive index, n, nonexistent in natural materials. The recent development of metamaterials with negative n confirms that structures can be fabricated and interpreted as having a negative permittivity, ε, and a negative permeability, μ, simultaneously. Since the original microwave experiments for the demonstration of negative index behavior in split ring resonators (SRRs) and wire structures, new designs have been introduced, such as fishnet, that have pushed the existence of the negative refraction at optical wavelengths 1, 2. Most of the experiments with the fishnet structure measure transmission, T, and reflection, R, and use the retrieval procedure 3,4 to obtain the effective parameters, ε, μ, and n. Although, stacking of three 5, four 6, five 7 functional layers and recently fabricated 8 ten-functional layer fishnets (21 layers of silver and MgF2) have been realized, they do not constitute a bulk metamaterial. Even the thickest fabricated 8 fishnet structure only has a total thickness, 830 nm, half of the wavelength (λ=1700 nm). However, it is very important to study how the optical properties change as one increases the number of layers. How many layers are needed to achieve convergence of the optical properties? How do optical properties behave as one change the distance between two neighboring fishnets? If the distance is small, we have a strong coupling case. The convergence of optical properties is slow, and more importantly, it does not convergence to the isolated fishnet case. What is the mechanism for negative n in the strong coupling limit? Here, we report a detailed study of the weakly and strongly coupled fishnets to understand the origin of negative n, as well the mechanism of low losses (that is, high figure of merit (FOM)) for the strongly coupled fishnets. We also study the convergence of the retrieval parameter (ε, μ, and n) as the number of unit cells (layers) increases. For the weakly coupled structures, the convergence results for n and FOM are close to the single unit cell. As expected, for the strongly
coupled structures, hybridization is observed and the retrieval results for n and FOM are completely different from the single unit cell. We demonstrate that the high value of FOM for the strongly coupled structure is due to periodicity
effects.

With the third generation ground-based gamma-ray telescopes delivering over a hundred new TeV emitting objects and with the new Fermi satellite providing greatly improved sensitivity in the GeV energy regime, gamma ray astronomy is entering a golden age. I will review the basics of ground-based gamma-ray astronomy and the Air Cherenkov Telescope method of detection and then describe my work on VERITAS - an array of four gamma ray telescopes located at Mt. Hopkins, Arizona. I will describe some of the recent results from the first two years of the VERITAS observing program, paying attention to the observations of several new active galactic nuclei and the discovery of the starburst galaxy M82 in TeV gamma rays. I will then summarize investigations using data from the Sloan Digital Sky Survey and Fermi to look for potential new VHE gamma-ray targets.

Abstract:
We propose a Gaussian scalar field theory in a curved 2-D metric with an event horizon as the low-energy effective theory for a weakly confined, invariant Random Matrix ensemble. The presence of an event horizon naturally generates Hawking radiation, which introduces a finite temperature in the model in a non-trivial way. A similar mapping with a gravitational analogue model has been constructed for a Bose-Einstein condensate pushed to flow at a velocity higher than its speed of sound, with Hawking radiation as sound waves propagating over the cold atoms. All these systems share the same non-trivial 2-point correlation function, which breaks translational invariance. Our work suggests a three-fold connection between a moving BEC system, black-hole physics and unconventional RMEs.

Since July 2007, Galaxy Zoo has involved through the Internet ¼ million members of the general public in providing morphological classifications by eye of nearly a million galaxies from the Sloan Digital Sky Survey. Scientists utilizing this unique database produced by “citizen scientists” have published thirteen peer-reviewed papers to date and more are on their way. NASA and the NSF have recently funded an initiative called the Zooniverse to expand the Galaxy Zoo model and construct a virtual facility that centralizes the ability for researchers across many disciplines to utilize human perception and pattern matching acumen in data processing pipelines. In this talk, I will provide an overview of Citizen Science and describe why humans are needed to process the veritable flood of data arriving from telescopes, satellites, remote sensing devices and scanned print. I will then present the plans for the Zooniverse giving brief overviews of the exciting new “Zoos” we are launching over the next 18 months and describe some of the excellent education opportunities available through the Zooniverse.

Hydrogen storage remains one of the main challenges in the implementation of a hydrogen based energy economy. Although several different approaches are being pursued, sorption onto a porous high surface area material is a leading contender. Remarkably, recent experiments using the spillover method are operating at room temperature, and are approaching the real-world targets as set by the Department of Energy for potential use in fuel cell cars. Spillover works by using nanoscale metal catalysts distributed through the porous substrate material to break the hydrogen molecules into atomic hydrogen which then attaches to the substrate. The best results have been on metal-organic framework materials.

The sample preparation for these hydrogen spillover experiments is quite complex, and there has been significant scatter in the experimental results. Without clear predictions for saturation storage capacities, it has been difficult to evaluate the experimental results. It has also been difficult to improve the early and best results.

In this project, accurate predictions for saturation storage density at room temperature for a wide range of experimentally interesting materials will be determined using quantum chemistry calculations of binding energies for individual and multiple hydrogen atoms on model molecules. Instead of estimates based on surface area, we are counting specific binding sites on the crystal surface. Our current work shows that many of the experimental results are a factor of 3 below theoretical predictions. Therefore, these materials require further improvement in sample preparation in order to achieve their full hydrogen storage potential.

The project will also test new materials to improve storage density above useful DOE targets and to improve substrate durability. Preliminary work suggests that new metal-organic and covalent-organic substrate materials can have saturation storage densities above 6 wt%. Issues of lattice shrinkage and strain will also be addressed. New materials have also been proposed that are more resistant to water. Rolled and modified graphene based materials will also be investigated for their hydrogen storage potential.

These studies have a direct application to ongoing hydrogen storage experiments by spillover. Together the theory and experiment provide an exciting path forward for hydrogen storage at room temperature. Existing experimental results for spillover on IRMOF-8 with bridge building have provided the best storage results within the sorption framework at room temperature. The ability to provide significant sorption capability at room temperature is a giant step forward. These avenues provide an opportunity to meet or exceed the Department of Energy targets for useful hydrogen storage for mobile and transport applications of 6.5 wt %.

Contemporary structural realists are proposing a radical revision of our fundamental ontology: we should eliminate objects and replace them with "structure": the world, in and of itself, is structure. The argument for this ontological version of structural realism begins from an alleged "metaphysical underdetermination" afflicting standard "object-oriented" scientific realism. I think that the argument fails, and I will discuss one reason why (the most interesting one, of course). This discussion focusses our attention on the concepts of object and individual, and on a view of physical objects that, I argue, originated with Newton in his discussion of Descartes on bodies and motion.

There is a positive outcome for structural realists, however, because the resources that the ontic structural realist employs when developing the argument from metaphysical underdetermination can be re-deployed to create a more promising strategy.

The draft papers that I will draw on for my talk can be found at http://www.nd.edu/~kbrading/Research/research.html: the structural realism stuff is in the joint paper with Alex Skiles, and the Descartes/Newton stuff is in 'Newton's law-constitutive approach to bodies: a response to Descartes'.

Cosponsored by the Minnesota Center for Philosophy of Science.

Studies of semileptonic decays of the charmed mesons D0, D+, and Ds+ allow for precision measurements of two of the nine weak interaction Cabibbo-Kobayaski-Maskawa matrix elements. Because these decays are governed by both the weak and strong force, extraction of the matrix elements requires knowledge of the strong interaction effects. These effects are parametrized by form factors of the hadronic final state. Experimental measurements of these form factors are used to test various form factor predictions of charmed meson decays and also to verify the framework for form factor predictions of semileptonic decays of other particles. The CLEO-c experiment collected the products of e+e- annihilations with the e+e- beams provided by the Cornell Electron Storage Ring. Its final data samples consist of 5.4 million D0 D0bar + D+ D- events from direct production of the psi(3770) resonance and 550 thousand Ds+- Ds*-+ events from annihilations near the center-of-mass energy of 4170 MeV. I will present results of inclusive and exclusive semileptonic decays of
the D0, D+, and Ds+ mesons using these samples. This is a practice talk for my presentation to be given at the "International Workshop on e+e- Collisions from Phi to Psi" (PHIPSI09).

Using the history of understandings about gravity as a template Dr. Quinn talks about how science works and show how our understanding is driven forward by the interweaving of threads that arise in observations and in theory building. Dr. Quinn stresses the importance of seeking consistent interpretations of apparently inconsistent ideas or observations as a key to progress in science.

The lecture will be held at 7:00 p.m., Tuesday, October 6, 2009 in Memorial Hall, McNamara Alumni Center, 200 Oak Street S.E., Minneapolis. Dr. Quinn’s presentation is the fourth in the William I. Fine Theoretical Physics Institute’s annual Misel Family Lecture Series.

The William I. Fine Theoretical Physics Institute at the University of Minnesota is proud to host the Irving and Edythe Misel Lecture Series. Mr. Fine’s bold vision and generous gift to the University, inspired by his genuine interest in physics, were instrumental in the establishment of the Institute and its successful development over the past two decades.

The Misel Lecture Series is endowed by a generous gift from Irving and Edythe Misel. The Series honors the life-long friendship between Irving and Edythe Misel, their family, and William and Bianca Fine.

For more information, please visit www.ftpi.umn.edu

The laws of physics for matter and antimatter are very, very similar. Yet we live in a Universe where matter dominates over antimatter by many orders of magnitude. When and how did this imbalance occur? This is a question at the root of our existence, but one for which, as yet, we do not have a satisfactory answer. I will review the physics of this problem, and the possible answers that are suggested by our current understanding of the history of the Universe and of the differences between the behavior of matter and antimatter, known as CP violations.

A cell-free expression system is used to reconstruct genetic circuits in vitro. Reactions are carried out in batch mode to study quantitatively the properties of synthetic genetic circuits. The extract can be also encapsulated in synthetic phospholipids vesicles. This system is used as a model of protocell. Perspectives and limitations of this approach will be discussed.

The early proper motion surveys conducted by Willem Luyten discovered thousands of so-called common proper motion binary stars. Such loosely bound pairs have separations ranging up to ~0.1 parsecs, implying extremely long orbital periods and no significant interaction between components. In many ways such "fragile binaries" are like open clusters with only two components of the same age. They provide a largely overlooked avenue for the investigation of many astrophysical questions. For example, the orbital distribution of fragile binaries with two long-lived main sequence components provides limits on the cumulative effects of the Galactic environment. In pairs where one component is evolved, the orbits have been amplified by post-main-sequence mass loss, potentially providing useful constraints on the initial-to-final mass relation for white dwarfs. In addition, the cooling ages of white dwarf components provide useful limits on the ages of their main sequence companions, independent of other stellar age determination methods. This talk will summarize how fragile binaries provide useful leverage on these and other problems of astrophysical interest.

Galileo did himself in. True, he had help, whether from Paul V and Urban VIII, the Jesuits, the Dominicans, the Congregation of the Index or even the Inquisition, but his fate was still largely his own fault. This talk focuses on his two trials before the Roman Inquisition, first in 1615–16 and again in 1632–33, the second leading to his condemnation for violating an order given in 1616 to abandon the belief that the sun was the center of the universe. Unlike most previous approaches, mine does not assume that the outcome was inevitable. Nor does it assume that philosophical, scientific or even theological issues were necessarily determinative. Instead, it takes a legal and political approach beginning from the fact that Galileo arrogantly rejected a legal way out of his second trial. Since both of his investigations contained lots of legal oddities, examining the Inquisition’s procedures (which have almost been ignored until very recently) leads to a much different picture than the still dominant view that Galileo was a victim of intolerance and superstition. Unfortunately, the Vatican’s recent proposal to reopen the case (including yet another publication of its acts) rests on at least two fundamental misunderstandings of Inquisition procedure: the fact that three cardinals and the pope did not sign Galileo’s sentence is insignificant. Popes never signed sentences and at least some of the cardinals often did not. Some sentences were signed only by the Inquisition’s commissary. Despite Urban’s missing signature, in both trials the pope’s role turns out to be vital. But equally, in both cases Paul and Urban had to at least bend if not break the rules in order to bring Galileo to book. He gave them both plenty of provocation.

Cosponsored by the Center for Early Modern History.

In this seminar, I will discuss the main signatures of dark matter candidates which are described by effective quantum field theories. In this kind of models, the interaction of the dark matter particle is characterized by a dimension-full parameter, that offers different possibilities than the dimensionless coupling, typical of renormalizable quantum field theories. I will analyze the abundance and the main phenomenological signatures of these candidates from astrophysical observations and their interplay with high energy or precision experiments. I will illustrate all these ideas with a particular candidate motivated from brane-world scenarios: the branon.

Earth’s high latitude ionosphere, highly disturbed by the particle and energy inputs and associated aurora, is the stage for plasma wave activity across a wide range of frequencies. These waves often exhibit strikingly distinct time-frequency structure which can have relatively direct explanations based on the dispersion relations of the appropriate normal modes of the plasma. Hence, they present an opportunity to confirm basic plasma physics. Moreover, once a physical explanation is proven for these emissions, it is often possible to exploit the structured waves to either measure characteristics of the local plasma or remotely sense characteristics of plasmas through which the waves have propagated. Observations of structured HF emissions from three recent auroral sounding rockets are presented.Identifying the wavemode of observed emissions is the first step in characterizing them, and I will present a novel technique that has been developed to constrain the mode of observed emissions by taking advantage of the orientation of the electric field sensors. In addition, auroral rocket observations of two structured emissions having distinct frequency-time patterns, “swishers” and “stripes,” are investigated. Ray-tracing and growth rate calculations provide effective tests of the mode identification and possible generating mechanisms of these emissions. Lastly, rocket observations of waveform statistics and spectra of short intense bursts of Langmuir waves in the polar cusp ionosphere reveal information about the modulation of these waves and the density fluctuations in which they arise. Taken together, the observations of these dispersed features and the development of new techniques to constrain their modes and identify their generation mechanisms add to our existing knowledge of the auroral ionosphere and show promise in remote sensing plasma characteristics elsewhere in the Earth’s magnetosphere and beyond.

Particle collisions are expected at the Large Hadron Collider before the end of 2009, and the collision energy should reach 7 TeV in early 2010. Though the center of mass energy and luminosity will be well below the design values, the data will already be useful in the search for physics beyond the Standard Model. I will describe two proposed searches by the Compact Muon Solenoid (CMS) experiment that could observe new physics signatures with early data. One study searches for large missing energy in dijet events, which could be the result of pair production of squarks followed by the decay of each squark to a quark and a neutralino. The second study examines the data recorded when there are no proton-proton collisions at CMS in order to search for long-lived particles that come to rest within the detector volume.

A microscopic understanding of the Ferromagnetic/Antiferromagnetic (F/AF) direct exchange coupling or exchange biasing has been elusive for the over 50 years since its discovery. In part, the almost exclusive use of hysteresis loops to study the phenomenon has limited our understanding. We developed a new experimental technique to study the exchange coupling between a ferromagnet and antiferromagnet Appl. Phys. Lett. 69,3932-3931 (1996). This new technique enjoyed considerable success in explaining many general exchange bias features using Co/CoO as a model system J. Appl. Phys. _87_, 6418-20 (2000), J. Appl. Phys. _89_, 7543-5, (2001), and Phys. Rev. _B 65_(RC) 180406-10(2002). After the Co/CoO work we used variations of the technique to study the angular dependence of the interfacial energy in Fe/MnF_2 bilayers. We were able to explain the observations using a microscopic model Phys. Rev. _B 65_(RC), 100402, (2002), Phys. Rev. _B 68_, 054430 (2003). The microscopic model includes terms for the interfacial exchange coupling, uncompensated spin density in the AF, the AF spin-canting energy, and domain walls in the AF. Application of the model to the Fe/MnF_2 bilayer experimental data allows one to separately determine the fraction of uncompensated interfacial spins in the AF layer and the interfacial exchange coupling energy for the first time. An understanding of the spatial distribution of the microscopic energies allows for a simplification of the energy in which the physics is transparent.This work supported by the University of Minnesota MRSEC

Bhattacharya will discuss the distinguishability of the non-universal gaugino mass scenarios and the non-universal scalar mass scenarios, that arise in SUSY-GUTs or in phenomenological models constructed to satisfy several low-energy constraints, from the so-called minimal supergravity (mSUGRA) set-up in context of the LHC in the 'multilepton channel' signature space.

We use simple coexistence rules for the phase diagram of the iron arsenides to deduce the pairing state in these new superconductors. Recent experimental evidence in the iron arsenite superconductor Ba(FeCo)2As2 demonstrates that antiferromagnetic long range order coexists with bulk superconductivity. We show that static antiferromagnetism can be used to probe the Cooper pair wave function in this coexistence region. Magnetism leads to a Josephson like coupling between Cooper pairs in different Fermi surface sheets. The relative phase of the gap function then determines whether superconductivity and antiferromagnetism are merely competing or are mutually exclusive. While conventional superconductivity yields a phase diagram with a first order transition, terminating at a bicritical poing, a tetracritical point is only possible for unconventional pairing states, where the order parameter has different sign on different pieces of the Fermi surface. We demonstrate that the observed phase coexistence is not compatible with conventionalsuperconductivity and find strong evidence for superconductivity where the order parameter on different Fermi surface sheets is out of phase. The robustness of our conclusion is caused by the fact that the system is in the vicinity of an SO(6)-symetric fixed poing.

One of the current frontiers in magnetism is to understand the domain structure and the magnetization reversal in nanometer sized particles. Explorations at these length scales have been aided by the development of new magnetic imaging techniques 1 one of which is the magnetic force microscope (MFM), a variant of the atomic force microscope. We have utilized the high resolution MFM (30 nm) we developed 2 to increase our fundamental understanding of magnetism on this length scale. I will discuss the field induced magnetic reversal in stadia shaped particles on the order of hundreds of nanometers wide and about twice that in length. In general for the small aspect ratio stadia (length to width ratio) the magnetization reverses by the formation of a single vortex and its propagation down the length of a stadium (when the fields are applied perpendicular to the long axis). The surprising discovery is the importance of virtual particles (vortex-antivortex pairs) creation and annihilation in the magnetic reversal in larger aspect ratio stadia.

1. E. Dan Dahlberg and Jian-Gian Zhu, Physics Today _48_, 34 April 1995.

2. George D. Skidmore, Sheryl Foss, and E. Dan Dahlberg, Appl. Phys. Lett. _71_, 3293-3295 (1997).

Supported by ONR and the University of Minnesota MRSEC.

The interaction of psychiatry with culture and society at large, as well as with the sciences and technology make a fascinating subject matter for the historian. Ever since electricity became a object of science during the eighteenth century there has been speculation about the role of electricity in the nervous system and the use of electricity for therapeutic purposes in psychiatry. From this perspective I will address three topics: madness and electricity in the 18th century; the importance of electrophysiology and electrotherapy in establishing biological psychiatry and neurology in 19th century Germany and the debate on electroconvulsive therapy during the last decades of the 20th century.

Cosponsored by The Bakken Museum

I will discuss the design specifications that drove the design of the CMB polarization anisotropy experiment EBEX. In particular, I will focus on the need for detector sensitivity in order to measure the B-mode polarization signature to a chosen level, the ability to isolate and subtract foreground sources such as polarized dust signal, and need to reduce systematic error to reduce E-B mixing.

The thermodynamics and critical exponents and amplitudes of high temperature and dense matter near the chiral critical point is studied. The parameterized equation of state matches on to that calculated with lattice QCD at zero chemical potential and to the known properties of nuclear matter at zero temperature. The extent to which finite size effects wash out the phase separation near the critical point is determined. The degree to which the critical point acts as an attractor in high energy heavy ion collisions is also investigated.

Superconductivity is a powerful tool for the detection of electromagnetic radiation over an extraordinary range of frequencies. The superconducting transition-edge sensor (TES), for example, is an extremely sensitive detector over more than twelve orders of magnitude in frequency, from microwaves through gamma rays. The TES uses a superconducting film biased in the superconducting transition as a sensing element. TES arrays have evolved beyond the research and development phase, and they are providing improved sensitivity in applications as diverse as nuclear non-proliferation and forensics, nuclear and particle physics, and cosmology. These arrays are instrumented by superconducting quantum interference device (SQUID) amplifiers. I will discuss the development of these detectors, and highlight their use in nuclear non-proliferation and cosmology, where they are providing new capabilities for sensitive measurements of the elemental and isotopic composition of nuclear materials, and the power and polarization of the cosmic microwave background.

The superconductor-insulator transition in the presence of strong compensation was recently realized in La doped YBCO. Compensation of acceptors by donors makes it possible to change independently the concentration of holes n and the total concentration of charged impurities N. We propose a theory of the superconductor-insulator phase diagram in the (N, n) plane, which exhibits interesting new features in the case of strong coupling superconductivity, where Cooper pairs are compact, non-overlapping bosons. For compact Cooper pairs the transition occurs at a significantly higher density than in the case of spatially overlapping pairs. We establish the superconductor insulator phase diagram by studying how the potential of randomly positioned charged impurities is screened by by strongly bound Cooper pairs. The pairs are either delocalized or localized in the resulting self-consistent potential.

Research in the Thomas lab focuses on the structure, dynamics, and function of muscle proteins, using the tools of site-directed labeling, time-resolved spectroscopy and computational simulation. This lab has unique resources in instrumentation and expertise. Several projects will be described that are designed for Physics grad students who wish to explore opportunities in the rapidly growing field of biophysics.

email: ddt@umn.edu
http://ddt.biochem.umn.edu

* NOTE: Different location *

We often employ mathematics in science to bypass the accidents of human consciousness, but in representing time, mathematics may not only help physics, but also lead us astray just as surely as the limitations of our own organism.

Cosponsored by the Minnesota Center for Philosophy of Science and the Department of Philosophy.

Observational indications for different types of core-collapse supernovae
and their characteristic neutrino emission will be reviewed. The various
effects associated with neutrino oscillations will be discussed. The
neutrino signals expected from different types of supernovae will be
examined as probes of supernova physics and neutrino properties.

Please join us for The School of Physics and Astronomy Chili Cook
Off! Come and taste some delicious chili, vote for your favorites,
socialize, and raise some money for the CFD! Costumes are welcome!

During the 1970’s, it was discovered that adding hydrogen to amorphous silicon (a-Si), producing hydrogenated amorphous silicon (a-Si:H), drastically reduced the density of defect states, resulting in an improved material. This opened the door for many discoveries with important technological applications, including the observation of doping, previously thought to be impossible in amorphous semiconductors. Following this revolution in the field, unhydrogenated amorphous silicon (a-Si) was largely left behind despite unsolved questions concerning the transport mechanisms in the material. These questions cover both conductivity and the thermoelectric power. Our group isrevisiting these questions and will present a brief overview of the current knowledge, as well as some new research on unhydrogenated amorphous silicon.

The heavy ion collision experiments are in progress in order to
investigate how the Universe has evolved after the Big Bang. The recent
observations show that a nearly perfect fluid is produced after heavy
ion collisions. An appropriate incorporation of the relativistic
hydrodynamics and the field theory would help us to describe the
dynamics of QCD (Quantum Chromodynamics) matter under extreme
conditions, and to survey the expected phase transitions. Some efforts
to investigate the characteristics of the QCD plasma are devoted to an
ideal, non-dissipative one. To get the results which are highly in
accordance with the experiment, it is necessary to bring also in mind
the role of dissipation, particularly the second order dissipation,
because the first order dissipation will result in instabilities and
causality violation. We are to couple the field theory and the
hydrodynamics of the dissipative fluid in such a way that the effect of
second order dissipative coefficients in addition to the effect of the
fields will emerge in the properties of the quark-gluon plasma (QGP)
such as sound velocity. In this seminar, after deriving the
thermodynamical potential using the effective potential of the linear
sigma model, we will study the effect of second order dissipation on the
sound velocity in the QGP and its variation near the chiral phase
transition.

The discovery of CP Violation in kaon decays 1964 created quite a shock in the HEP community despite the fact that parity violation had been established a few years earlier. The impact of this discovery can be illustrated by the very peculiar theory that had been suggested for it: the KM ansatz seemed a priori unlikely to be correct. Yet since the turn of the Millenium it has been empirically validated in the decays of B mesons to an impressive degree -- while failing to provide a scenario for baryogenesis. This success of the Standard Model of HEP does not invalidate the experimental and theoretical arguments for its incompleteness. The task of uncovering the dynamics driving electroweak symmetry breaking provides our
generational challenge. It will be addressed by experiments undertaken at the LHC. A dedicated continuation of comprehensive studies of heavy flavour transitions will be a central element in confronting this challenge.

Title: Cyclic cosmologies: playing the devil's advocate

Abstract: Cyclic/Bouncing cosmologies offer an interesting non-singular and geodesically complete alternatives to inflation. However, there are several challenges that plague them to providing a theoretically consistent and phenomenologically viable model. I will attempt to give a brief overview of these issues before pointing to some of the possible future directions.

Complex oxides such as perovskites have emerged as one of the most important platforms for the discovery of new phenomena in condensed matter physics. Colossal magnetoresistance in the maganites, and high temperature superconductivity in the cuprates are classic examples. The extraordinarily diverse physical phenomena displayed by these materials is due in large part to the strong competition between the various active degrees of freedom, which leads to a subtle energy balance between the multitude of available ground states. It is perhaps unsurprising that under these conditions, particularly in randomly doped systems, nanoscopic electronic inhomogeneity is ubiquitous. “Magneto-electronic phase separation”, where multiple electronic and magnetic phases coexist spatially, even in the absence of chemical segregation, has been observed in a wide range of materials and is widely believed to be due to electronically-driven phase separation. In this talk I will elaborate on the features of the doped perovskite cobaltites (e.g. La1-xSrxCoO3) which make them model systems for the study of this nanoscopic phase separation. We have used single crystals of these materials to study the phenomenology, consequences, and origins, of the magnetically phase-separated state, mostly by neutron scattering, transport, and heat capacity. Our primary conclusions are that (i) the spontaneous magnetic nanostructuring has many interesting consequences including the existence of “GMR-type” effects in a bulk solid, and (ii) the magnetic phase separation is driven purely by the local doping fluctuations that are inevitable at these nanoscopic length scales. In essence the nanoscale inhomogeneity is doping fluctuation-driven rather than electronically-driven, challenging, at least in these materials, the commonly accepted electronic phase separation scenario

Nanomagnetism and quantum spintronics is an exciting field of research combining two traditional branches of physics: magnetism and electronics. Distinguishing and manipulating the up-spin and down-spin through nano-scale structuring of magnetic materials and devices is expected to add new dimensions to the practice of quantum electronics. This seminar will report recent advances made in author’s group on spintronic devices and magnetic nanoparticles and a discussion of research opportunities and challenges of this field. Spin Torque Transfer (STT) or so-called current-induced magnetization switching (CIMS) has advantages in the device scaling compared to the field-switching mechanism. Challenges for the spin-torque-transfer devices will be laid out and discussed for future Spin-RAM, Spin-Logic and Spin-Oscillator. Heterostructured magnetic/spintronic nanoparticles, with multiple functions and enhanced properties arising from the interaction of individual components within the single particle, have been designed and fabricated by a novel micro/nano-electronic compatible vacuum process in author’s group. An unusual surface nanomagnetism of L1_0 phase FePt nanoparticles has been discovered recently by the author and his student (Liu), which will be reported in this seminar too.

Biography

Dr. Jian-Ping Wang joined the faculty of Department of Electrical and Computer Engineering at University of Minnesota as an associate professor in Sept. 2002 and has been a professor since May 2009. He joined the graduate faculty of Physics Department at U of M in 2007. His current research programs focus on searching, fabricating and fundamentally understanding new nanomagnetic and spintronic materials and devices. He obtained his Ph. D degree from Institute of Physics of Chinese Academy of Sciences, Beijing, in 1995. He has built and run the Magnetic Media and Materials program in Data Storage Institute, Singapore, as the founding program manager, from 1998 to 2002. He has been graduate faculty member at National University of Singapore from 1996 to 2002. He has authored and co-authored more than 190 publications in peer-reviewed top journals and conferences and hold 12 US patents (9 granted and 3 pending). He has involved in program committees for several major magnetic and materials conferences such as MMM, PMRC, TMRC and MRS. He won the INSIC 2006 Technical Achievement Award.

Spectroscopic observations of novae date back a century, and the fundamental nature of the outburst has been understood for 50 years. Yet, recent observations suggest a possible significant modification to the standard nova paradigm. A high-resolution spectroscopic survey of novae has revealed short-lived heavy element absorption systems near maximum light consisting of Fe-peak and s-process elements. The spectroscopic evolution of novae is interpreted in terms of two distinct interacting gas systems in which the bright continuum is produced by the outburst ejecta but absorption and emission lines originate in gas ejected by the secondary star in a way that may explain dust formation and X-ray emission from novae. The absorbing gas is circumbinary and it pre-exists the outburst. Its origin appears to be mass ejection from the accretion disk or secondary star, and it may be initiating the nova outburst.

In 1909, Albert Einstein derived a formula for the mean square energy fluctuation in a small subvolume of a box filled with blackbody radiation. This formula is the sum of a wave term and a particle term. In a famous joint paper with Max Born and Werner Heisenberg submitted in late 1925, Pascual Jordan used the new matrix mechanics to show that one recovers both these terms in a simple model of quantized waves. So, contrary to what Einstein had concluded in 1909, the two terms do not require separate wave and particle mechanisms, but arise from a unified dynamical framework. This result not only solved Einstein's puzzle about the wave-particle duality of light, it also provided striking evidence for matrix mechanics, and can be seen as a strong argument for field quantization. After a brief review of Einstein's early work on fluctuations in blackbody radiation, I will present Jordan's result and the curious story of its reception. Rather than being hailed as a major contribution to quantum theory, Jordan's result met mostly with skepticism, even from his co-authors. I will argue that the skeptics were wrong. This talk is based on a joint paper with Anthony Duncan, "Pascual Jordan's resolution of the conundrum of the wave-particle duality of light." Studies in History and Philosophy of Modern Physics 39 (2008): 634-666.

The interesting interactions at the LHC require knowledge of the parton distribution functions (PDFs). The shape of the Z boson rapidity distribution is used as a direct probe of the PDFs, as each region of rapidity samples a different Z spectrum, and thus is sensitive to PDF variations. The measurement is particularly sensative to low |rapidity| and high |rapidity|. The results for 100 inv-pb of fully simulated data are presented, as well as a discussion on the statistical precision and systematic error contributions.

I use the AdS/CFT correspondence to explore the non-perturbative realms of a QCD-like theory at finite temperatures. One hopes the strongly-coupled Quark-Gluon Plasma (sQGP) could be succinctly described by such a model.

A few hundred thousand years after the Big Bang the primordial gas recombined, became transparent - the last light from that we now see as Cosmic Microwave Background. There was very little structure in the universe at that time, no source of light - we call it now the Cosmic Dark Ages. It would take several hundred million years before the first stars in the universe would form, making the first source of light after the big bang, when the "dark" matter could clump, collecting up baryonic matter that could cool down, and condense into the first stars. Still, the gas was quite warm, so it would take massive, big clouds to collapse under their own gravity, making big stars. At least, this is what out best theories tell us. But no one actually has ever observed this to date. So, is that story true? How big were the first star actually? What can we do to find out? Looking at the current universe, we do see that some quite big stars are still formed today, but they shed mass in massive winds and in giant eruptions and will die not quite as big as they were born. Is the same true for the first stars if born as big as the biggest stars we see today? Or were there even bigger stars, and how would the evolve and die? Could these latter once be the predecessors of the supermassive black holes harbored in the centers of even some of the earliest galaxies we see? So, how can we find out? At least part of the story we may be able to uncover now by looking at ashes of the first stars, the pattern of elements that made and that were incorporated in subsequent generations of stars. Observes now have found some very old stars in the halo of our galaxy, one of its oldest constituents, that likely have formed very early in the universe. These stars have only miniscule traces of heavy elements, they almost exclusively consist of the matter made by the big bang. We now believe that many of those likely have been "polluted" only by a few, maybe a single star. But the ratio of heavy elements that a star makes depends a lot on how massive is was, and how it died. So looking at the ashes of these first stars, as incorporated in the old stars we have found, may tell the story of the lives of those first stars. What will we discover?

Abstract :

We consider a left-right symmetric SU(4)_c X SU(2)_L X SU(2)_R (4-2-2) model with gravity mediated supersymmetry breaking. We find that with 4-2-2 compatible non-universal gaugino masses, t-b-tau Yukawa coupling unification is consistent with neutralino dark matter abundance and with constraints from collider experiments. The gluino mass lies close to that of the lightest neutralino, so that the gluino co-annihilation channel plays an important role in determining the neutralino relic abundance. We also explore regions of the parameter space in which the little hierarchy problem is partially resolved.

In certain very thin regimes of ferromagnetic materials, it is energetically favorable for vortices to condense. I will discuss how such vortices move when driven by the Landau-Lifschitz-Gilbert equations. I will show how such a result can be proven by understanding some intrinsic quantities and their conservation laws.

Proteins are nature’s nanomachines and perform the essential cellular processes that keep you and me alive. While much physical research has centered on characterizing the dynamics and behavior of isolated proteins, it has become increasingly clear that proteins are not loners, but team players. The modern view of cell function is based on intricate networks of protein-protein interactions. These networks are not the result of randomly colliding individual protein molecules. We now know that nearly every major cellular process is carried out by assemblies of protein molecules. Our lab develops techniques for the direct and quantitative characterization of protein assemblies inside living cells. I will introduce the experimental technique and discuss two applications: (1) the initial interactions that lead to gene activation, and (2) the assembly of the HIV retrovirus.

The Hercules Thick Disk Cloud (Larsen et al. 2009) was first initially
discovered as an excess in the number of faint blue stars between
quadrants I and IV of the Galaxy. The field stars responsible for the
excess, are between 2 and 4 kiloparsecs from the Sun, 1.2 kpc above the
Galactic plane, and the asymmetry feature or Cloud is kiloparsecs in
length -- a major substructure in the Galaxy. The origin of the Cloud
could be an interaction with the disk bar, a triaxial thick disk or a
merger remnant or stream. To better map the spatial extent of the Cloud
along the line of sight, we have obtained multi-color UBVR photometry
for 1.2 million stars in 67 fields of approximately 1 square degree
each. Our analysis of fields beyond the apparent boundaries of the
excess rule out a triaxial thick disk as a possible explanation for the
Cloud (Larsen et al., accepted). In this talk we present our results
for the counts over all of our fields and characterize the size of the
excess. Over the entire 500 square degrees of sky containing the Cloud,
we estimate about a quarter of a million F/G type stars, bringing the
estimated mass of the Cloud to over a million solar masses.
Additionally, one of our quadrant IV fields contains a blue horizontal
branch feature that implies that a large number of stars are clumped in
a small range of distances. We have tentatively identified this clump
with the Cetus Tidal Stream of Newberg et al. (2009).

The Institute of Technology was created in 1935 and will celebrate its 75th anniversary in 2010. The IT Dean's office has commissioned an engaging and illustrated book-length of IT's history -- including its notable faculty, alumni, research and teaching. This presentation will give an overview of our research, and present our findings on the distinct aspects of the Institute of Technology. We accent IT's notable achievements in science and engineering, and profile its colorful leaders and faculty members.

Thermonuclear flashes in the outer layers of accreting neutron stars are observed as X-ray bursts. These bursts are instrumental in learning more about the inner parts of the neutron star: the crust and core. Usually, a neutron star accretes matter for at least several hours, before enough fuel is accumulated to trigger a flash. In rare cases, however, bursts are observed with recurrence times as short as ten minutes. We discuss the clues we gathered to try to solve this decades-old mystery.

The spectral split is the most interesting feature of neutrino
flavor transformation from the neutrino-neutrino interaction, which is dominant in a supernovae environment. A simple model to explain this phenomenon will be discussed.

The most stringent tests of physical theories are often provided by extremes. The planet Mercury’s interaction with the solar wind provides one such case for magnetospheric physics. Mercury is unique in that it possesses no significant ionosphere, and owing to the planet’s comparatively small magnetic moment, yielding a surface field one percent of Earth’s, Mercury’s magnetosphere is small and entirely dominated by the solar wind interaction. In solar orbit from 0.31 to 0.47 AU heliocentric distance, Mercury is also exposed to solar wind densities four to ten times higher than at Earth, an interplanetary magnetic field (IMF) about three times stronger, and a predominantly radial IMF, which changes the basic nature of the bow shock structure and dynamics. Finally, length and time scales that are widely separated at Earth and other solar system magnetospheres merge in the Mercury system. Energetic (>20 keV) protons and even thermal heavy ions have gyroradii comparable to the radius of Mercury’s magnetosphere. The largest-scale fluid-mode waves have transit times through the magnetosphere comparable to ion gyro-frequencies. Thus the convenient scale ordering that applies to other systems breaks down at Mercury. This seminar provides a summary of the initial findings from NASA’s Mercury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. Launched in August 2004, the MESSENGER spacecraft has successfully completed six planetary gravity assist maneuvers, one at Earth, two at Venus, and three at Mercury, placing the spacecraft on target for insertion into orbit about Mercury in March 2011. Results from the three Mercury flybys reveal a rapid-fire electrodynamic system with a magnetic recirculation timescale of only tens of seconds, magnetic reconnection events at least an order of magnitude more intense than at Earth, and large-scale boundary structures unique to Mercury. The correspondence with ion-kinetic/electron-fluid simulations give tantalizing suggestions of new physical insights that will be gained once the comprehensive survey in Mercury orbit begins in 2011.

Magnetic correlations might cause the superconductivity in the cuprates, and they are generally believed to be antiferromagnetic and to arise from the underlying copper-oxygen planes. Using neutron scattering on the model compound HgBa2CuO4+δ, we recently discovered the existence of a prominent magnetic excitation with unusual characteristics: (i) the excitation appears to involve active degrees of freedom on both planar and apical oxygen; (ii) it is present throughout the entire Brillouin zone; (iii) it exhibits a weak doping dependence and dispersion, and (iv) a maximum energy of 56 meV at the antiferromagnetic point, where it meets the magnetic resonance, a well-known spin-one excitation that appears in the superconducting state; (v) furthermore, unlike the resonance, the new exciation maintains its integrity in the normal state up to the pseudogap temperature (T*), and thus appears to be associated with the novel magnetic order recently identified in the pseudogap phase. I will also discuss our recent finding of a universal relationship between the magnetic resonance energy (Er) and the superconducting pairing gap (&Delta) that is valid for the three different classes of unconventional superconductors, ranging from being close to the Mott-insulating limit to being on the border of itinerant magnetism.

The startup of the LHC will bring an opportunity to finally solve some of the long-standing questions of fundamental particle physics, and possibly also provide insight about the nature of the dark matter which is crucial in the development and dynamics of galaxies and large-scale structure. I will discuss the status of the LHC, the work underway in the Minnesota CMS group, and the prospects for the next few years.

Although originally conceived as primarily an extragalactic survey, the Sloan Digital
Sky Survey (SDSS-I), and its extensions SDSS-II and SDSS-III, continue to have a
major impact on our understanding of the formation and evolution of our host galaxy,
the Milky Way. The sub-survey SEGUE: Sloan Extension for Galactic Exploration
and Understanding, excuted as part of SDSS-II, obtained some 3500 square degrees of
additional broadband imaging, mostly at lower Galactic latitudes, in order to better sample
the disk systems of the Galaxy. Most importantly, it obtained over 240,000 medium-resolution
spectra for stars selected to sample Galactocentric distances from 0.5 to 100
kpc. In combination with stellar targets from SDSS-I, and the recently completed
SEGUE-2 program, executed as part of SDSS-III, the total sample of
SDSS spectroscopy for Galactic stars comprises some 500,000 objects.

The development of the SEGUE Stellar Parameter Pipeline has enabled the determination
of accurate atmospheric parameter estimates for a large fraction of these
stars. Many of the stars in this data set within 5 kpc of the Sun have sufficiently well-measured
proper motions to determine their full space motions, permitting examination
of the nature of much more distant populations represented by members that are
presently passing through the solar neighborhood. Ongoing analyses of these data are
being used to draw an increasingly clearer picture of the nature of our galaxy, and to supply
targets for detailed high-resolution spectrscopic follow-up with the world’s largest
telescopes. We discuss a few highlights of recently completed and ongoing investigations with these data.

This talk will begin by postulating that the early predilections and particular trajectories of women's history and business history have contributed to the dearth of historical literature on women entrepreneurs and the complete absence of historical literature on women and entrepreneurship in computing. The core of the talk (based on several case studies) will focus on a hitherto unexplored, but significant segment of the computer services industry—IT independent contractor brokerages—and the critical role of women in launching firms and subsequently leading the primary trade association in this industry (NACCB). In doing so, it will seek to balance the important, nascent historical studies emphasizing educational and workforce barriers to women in computing, with narratives where initial barriers give way to entrepreneurial moments, and the themes of women's agency and leadership come to the fore.

Electronic confinement at nanoscale dimensions remains a central means of science and technology. In this talk, I will describe a method for producing extreme nanoscale electronic confinement at the interface between two normally insulating oxides, LaAlO3 and SrTiO3. Using a conducting atomic-force-microscope probe, we can create nanoscale conducting islands, nanowires, tunnel junctions and field-effect transistors, with spatial dimensions comparable to the diameter of a single-wall carbon nanotube (~2 nm). These structures are created in ambient conditions at room temperature, and can be erased and rewritten repeatedly. This new, on-demand nanoelectronics platform has the potential for widespread scientific and technological exploitation.

The discovery of a high-mobility two-dimensional electron gas at the interface between a polar and non-polar insulating oxide has motivated transport experiments aiming at eliciting various quantum effects. At room temperature, an electric field-tunable hysteretic metal-insulator transition was discovered. At low temperatures (below 1 K), interfacial superconductivity and magnetism were reported. Here, I describe low-temperature magnetotransport experiments in a nanowire formed at the interface between LaAlO3 and SrTiO3. Distinct plateaus are observed and associated with quantized magnetoresistance at integer and fractional Landau level filling factors ν=2,3,...,9, and the fractional filling factors ν=7/3 and 11/5. The quasi-one-dimensional nature of the conducting channel, combined with the large electric field-tunable dielectric permittivity of SrTiO3, is believed to contribute to the stability of the integer and fractional quantum Hall states.

After a brief introduction to the field of magnetism, magnetic materials, and magnetism-based technologies I will give an overview of the research performed in my group on magnetic materials. This research is performed on a wide variety of materials across a large span of length scales, from bulk single crystals, through heterostructured thin films, to magnetic nanostructures. The work includes studies of magnetic phase separation in complex oxides, charge and spin transport in oxide heterostructures, development of half-metallic ferromagnets, spin injection in metallic nanostructures, and block copolymer lithography of magnetic nanostructure arrays.

More information is available at:
http://www.cems.umn.edu/about/people/facdetail.php?cemsid=20233

The evolution of systems driven outside of thermodynamic equilibrium is characterized by strong nonlinearity and the formation of complex spatio-temporal patterns. We illustrate several key concepts by focusing on three prototypical situations: Rayleigh-Benard convection, Faraday waves, and defect motion in soft matter. In the first case, we discuss the appearance of non variational effects in an otherwise overdamped dynamical system, and how they lead to spiral defect chaos, an extended spatio temporally chaotic state. In the second, weak dissipation effects in a near Hamiltonian system account for the formation of quasi crystalline patterns on the surface of a vibrated fluid layer. In the latter case, we discuss topological defect motion in modulated phases, and mechanisms underlying the emergence of long range order.

I will give a brief introduction to the field of space plasma physics and its relationship to plasma physics and astrophysics. I will describe some interesting new results from the Minnesota group on relativistic electron acceleration, structure of shock waves, reconnection and energy transport via Alfven waves. I will briefly review current and upcoming projects that can involve graduate students.

A lot of new evidence has emerged in the past few years that provides clues to the formation of the Galactic halo. The Λ CDM model, so succesful in the cosmological context,
failed spectacularly when initially applied to this problem, but recent work has largely resolved these discrepancies. I will discuss the newly emerging view of the relationship between the
dwarf spheroidal satellites of the Milky Way, the Galactic globular cluster system, and the stellar halo of our galaxy.

It is shown that the Smorodinsky-Winternitz potential, BC_2 rational model, 3-body Calogero model, Wolves potential are all the members of a continuous family of planar solvable and integrable Schroedinger equations marked by some continuous parameter. Their spectra is always linear in quantum numbers. Hidden algebra of the family for integer values of the parameter is uncovered. It is non-semi-simple Lie algebra gl(2)x R^{k+1} realized as vector fields on line bundles over k-Hirzebruch surface. Obtained potential admits quasi-exactly solvable (QES) generalization with the same hidden algebra gl(2) x R^{k+1}. The question about super-integrability of the QES potential remain open yet.

Classical-mechanical analogue of the family is presented. It has a property of integrability while the solvability is replaced by a feature that all finite trajectories are closed.

I will describe experiments that attempt to understand the physics of the big bang. The experiments are balloon borne and are designed to observe the polarization of the cosmic microwave background radiation. By employing thousands of detectors that collect data over two weeks of balloon flight over Antarctica we hope to clarify physical processes that occurred as early as 10e-35 seconds after the big bang.

There has recently been a dramatic increase in our understanding of the supermassive black hole at the dynamical center of our galaxy, first identified as the nonthermal radio source Sgr A. Stellar orbit measurements have shown a mass of four million solar mass coincident with Sgr A and a luminosity which is several orders of magnitude lower than the Eddington luminosity. To study the underluminous nature of Sgr A, we have been monitoring the variability of the emission from Sgr A by making simultaneous multi-wavelength observations. I will present highlights of these measurements which are providing us with insights on the nature of the flow very near the event horizon as well as the emission mechanism in different wavelength bands. Time permitting, I will also discuss the origin of one or two discs of massive stars found within 0.5 pc of Sgr A as well signatures of young massive star formation in the molecular ring orbiting Sgr A.

Cosponsored by the Minnesota Center for Philosophy of Science and the Conceptual Foundations of Evolutionary Biology Interdisciplinary Graduate Group.

The organism is the fundamental unit of life and yet there is surprisingly little debate, and even less agreement, about what it is. Following on the realization that new levels of organisms have evolved from groups of lower-level organisms, we propose a social definition. An organism is a biological entity that has very high cooperation among its parts, and very little conflict, and is thus the locus of adaptation. We explore the implications of this view for what we consider to be organisms, and argue its advantages relative to earlier views.