Physics Colloquia

Dr. Vincent Smith, Honorary Research Fellow; University of Bristol (UK)
CERN: An In-Depth Look

CERN (near Geneva, Switzerland) was founded in 1954 by 12 European countries and now has 22 “member states.” I have been fortunate to have worked on experiments there since 1976, when the new Super Proton Synchrotron was commissioned. Since the late 1990’s, I have been a member of the Compact Muon Solenoid collaboration, one of the big experiments on CERN's Large Hadron Collider. I worked initially on the development, installation and commissioning of the Electromagnetic Calorimeter, a system of over 75,000 crystals of Lead Tungstate (PbWO_4) to measure the energy and direction of high energy gamma rays, electrons and positrons from collisions in the center of the detector.

As the University is currently on Spring Break, there is no colloquium scheduled for Friday, March 22.

There is no Physics colloquium currently scheduled for this date.

Aaron Viets, PhD Candidate, University of Wisconsin-Milwaukee

Optimizing Advanced LIGO's Scientific Output with Fast, Accurate, Clean Calibration

Fast, accurate calibration of Advanced LIGO data is an essential part of gravitational-wave astronomy, necessary for prompt electromagnetic follow-up of gravitational-wave events and reliable estimation of source parameters.

Victor Muñoz, University of California-Merced

Lessons About Biomolecular Rate Theory from Ultrafast Kinetics and Single-Molecule Spectroscopy of Fast-Folding Proteins

Natural proteins fold and unfold with rates that define their biological properties and vary vastly from protein to protein. Understanding how these rates are determined is essential to decipher the mechanisms of protein folding, but is also a convenient system to explore the fundamental aspects of biomolecular rate theory. Protein (un)folding rates are described as diffusion on a free energy surface obtained by projecting the protein-solvent hyper-dimensional phase space (or folding energy landscape) onto one or few order parameters that capture the reaction’s progress.

Piotr Marszalek, Duke University

Nanomechanics of Biopolymers Beyond Their Entropic Elasticity Regime

Compared to other single-molecule techniques, AFM-based force spectroscopy uses stiff force transducers and it may apply large stretching forces to molecules, enabling their structural modifications and capturing high energy conformations that cannot be examined by (for example) X-ray crystallography or NMR. In my talk, I will present our AFM stretching and relaxation studies, supported by computer simulations of individual molecules of DNA and proteins.

Professor Naomi McClure-Griffiths, Professor at the Research School of Astronomy & Astrophysics in the College of Science – Australian National University

The Milky Way and Magellanic Clouds as Laboratories for Understanding the Evolution of Galaxies

Galaxies are not closed box systems. Their evolution is impacted by gas accreted via inflow, gas lost from the disk via large-scale outflows and gas circulations via the halo. Many simulations of galaxy formation and evolution have highlighted the importance of feedback in reproducing the observable Universe. In this talk, I will present an overview of observational evidence for outflows within the Milky Way and Magellanic Clouds.

Daniel J. Kennefick, University of Arkansas

No Shadow of Doubt: The 1919 Eclipse and General Relativity

This is the centenary year of the celebrated eclipse expeditions of 1919 which confirmed Einstein's theory of General Relativity. In recent decades, the story of these expeditions has focused on Arthur Stanley Eddington and the question of his alleged bias in favor of Einstein’s theory. It has been alleged that Eddington threw out data which did not favor Einstein’s theory.

There is no Physics colloquium currently scheduled for this date.

Goutam Sheet, Dept. of Physical Sciences, Indian Institute of Science Education & Research (IISER)

Tip-induced Superconductivity

It has been recently observed that certain novel phases of matter, like superconductivity, emerge at mesoscopic interfaces between elemental metals and topologically nontrivial systems such as topological insulators and topological Dirac and Weyl semimetals. In this talk, I will review some of our published results on such mesoscopic superconducting phases with special emphasis on tip-induced superconductivity (TISC). A TISC phase is known to emerge under the point of contact between a sharp tip of a (non-superconducting) normal metal and a material with topologically non-trivial band structure.