Physics and Astronomy Colloquium

All future


Thursday, February 21st 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Flavio Cavanna, Yale
Subject: Lifting the lid on DUNE, the new international mega-science project in the US

The experimental discoveries of the last half century have placed neutrinos in the spotlight to unlock the mysteries of the matter's abundance unbalance in the Universe and of the ultimate fate of the stars. The lack of direct observations of proton decays, on the other hand, keeps at bay the dream that the forces of nature were unified at the beginning of time.
The Deep Underground Neutrino Experiment (DUNE) is the new leading-edge, international mega-science experiment for neutrino science and proton decay search.
DUNE will consist of two paired neutrino detectors placed in the world’s most intense neutrino beam. One massive detector will be installed deep underground at the SURF laboratory, in South Dakota — 1,300 kilometers away from FERMILAB, where the second detector will be positioned just downstream the neutrino source. Detecting the energetic beam neutrinos at the far site and comparing with those detected at the near site can give insight about our matter dominated universe. The underground location of the far detector, screened from the overwhelming cosmic ray flow, may allow to detect tiny signals from neutrinos originated by a core-collapse supernova in the Milky Way and thus possibly peer inside a newly-formed neutron star. And finally, the extra-large amount of mass of the detector may allow primordial symmetries to occasionally resurface inside a proton and spontaneously morphing a quark into a lepton, with the proton instantly falling apart into a detectable flash of radiation.
But not only large mass and far distance matter to pursue this ambitious discovery plan: unprecedented detection technologies and a worldwide effort to build the detector are required. DUNE will use the state-of-the-art Liquid Argon TPC technology to instrument deep underground 70.000 tons of Liquid Argon at 87K, with millimeter scale 3D precision.
A 1 kTon precursor of the far LAr-TPC detector has been constructed and recently activated at the CERN Neutrino Platform, and is now taking data. A first look of the spectacular events collected will be shown.

Faculty Host: Roger Rusack

Thursday, February 28th 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Joerg Schmalian, Karlsruhe Institute of Technology
Subject: Failed Theories of Superconductivity

Superconductivity is one of the most fascinating quantum states of matter. Almost half a century passed between the discovery of superconductivity by Kamerlingh Onnes and the theoretical explanation of the phenomenon by Bardeen, Cooper and Schrieffer (BCS). During the intervening years the brightest minds in theoretical physics tried and failed to develop a microscopic understanding of the effect. A summary of some of those unsuccessful attempts to understand superconductivity not only demonstrates the extraordinary achievement made by formulating the BCS theory, but also illustrates that mistakes are a natural and healthy part of scientific discourse, and that inapplicable, even incorrect theories can turn out to be interesting and inspiring.

Faculty Host: Rafael Fernandes

Thursday, March 7th 2019
08:00 am:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Marc Pinsonneault, The Ohio State University
Faculty Host: Evan Skillman

Thursday, March 14th 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Alexander Grosberg, New York University
Subject: Statistical Mechanics of Active Particles

Active particles are the ones having a source of energy to drive them, in addition to the usual Brownian motion. It could be swimming bacteria, or artificial swimmers of various kinds. Statistical mechanics of such out-of-equilibrium systems presents many steep challenges and features many unexpected phenomena. While energy barriers is a staple in physics (Boltzmann limit), force barriers are important for active particles (Sisyphus limit), leading to rectification of random walks, repulsive depletion, etc. Activity can also cause separation of active particles from passive ones even when there is no energetic preference for segregation. The latter effect is particularly strong for polymers, promising interesting applications in the physics of cell nucleus.

Faculty Host: Boris Shklovskii

Thursday, March 21st 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
There will be be no colloquium this week due to spring break

Thursday, March 28th 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Jason Hogan, Stanford
Subject: TBD
Faculty Host: Roger Rusack

Thursday, April 4th 2019
3:35 pm:
Van Vleck Colloquium in Physics Tate B50
Speaker: Rob Kennicutt, Texas A&M University
Subject: The Schmidt Law at Sixty

Sixty years have passed since Maarten Schmidt's conjecture that star formation in galaxies was closely coupled to gas density, and since that time the Schmidt law has become an indispensable tool for interpreting, modeling, and simulating large-scale star formation in galaxies. Despite its success as a sub-grid "recipe" for the star formation rate, however, we remain far away from an ab initio theory of star formation, or even a clear understanding of the observed scaling laws themselves. This talk will review the current state of our observational understanding of star formation in galaxies, and the complexity which lies beneath the surface of the observed SFR scaling relations. We are witnessing an observational and theoretical renaissance in the subject, as multi-wavelength observations reveal the multi-scale nature of the star formation process and the complex interactions which are taking place between cosmological, gravitational, interstellar, and stellar feedback processes on these different scales. The picture which emerges is one in which the superficially simple star formation scaling laws are manifestations of a highly dynamic, complex, and self-regulating ecosystem in galactic disks.

Faculty Host: Ronald Poling

Thursday, April 11th 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Dimitar Sasselov, Harvard
Subject: TBD
Faculty Host: Evan Skillman

Thursday, April 18th 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Ian Tregillis, Los Alamos National Laboratory
Subject: TBD
Faculty Host: Thomas W. Jones

Thursday, April 25th 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Sanjay Reddy, University of Washington
Subject: TBD
Faculty Host: Joseph Kapusta

Thursday, May 2nd 2019
3:35 pm:
Speaker: Jack Harris (Yale University)
Subject: TBD
Refreshments in atrium after the Colloquium.
Faculty Host: Paul Crowell

Thursday, May 9th 2019
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: David Weinberg, The Ohio State University
Subject: TBD
Faculty Host: Clement Pryke

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.