Physics and Astronomy Colloquium

semester, 2020


Thursday, January 23rd 2020
3:35 pm:
Speaker: Jos Uffink, University of Minnesota
Subject: Schrödinger and the prehistory of the Einstein-Podolsky-Rosen (EPR) argument
Refreshments in atrium after the Colloquium.

Although Schrödinger only coined the term "entanglement" (Verschränkung) in 1935, he had been worrying about the phenomenon of (what we now call) entanglement for composite systems since 1927. Indeed, he gave up on his original interpretation of the wave function precisely for this reason. At that time, he thought that Born's statistical interpretation of the wave function did not suffer from the same problem. In November 1931, his unpublished notebooks show that, in response to a lecture in Berlin by Einstein on the photon box experiment, he already developed all essentials of what we now know as the EPR argument, (Einstein, Podolski and Rosen, 1935). I will argue that Schrödinger’s role in the development of this argument have not yet been sufficiently appreciated until now.

Also, I will comment on the differences between Schrödinger’s and Einstein’s views on the conclusions to be drawn from this argument.

Faculty Host: Michel Janssen

Thursday, January 30th 2020
3:35 pm:
Speaker: Andrew Furmanski, University of Minnesota
Subject: Neutrino oscillations - the path to new physics?
Refreshments in atrium after the Colloquium.

The standard model of particle physics gives neutrinos no mass. The discovery that neutrinos can change flavor tells us they must have non-zero mass. In the 20 years since its discovery, ever more precise measurements of neutrino oscillations, including by two large experiments in Minnesota, have brought us to an era of precision measurements that may begin to explain the asymmetry between matter and antimatter in the universe, as well as potentially opening a window to entirely new physics. This talk will describe the history of neutrino oscillation measurements, and discuss two new experiments, DUNE and SBN, which are hoping to discover new physics through neutrino oscillations.


Thursday, February 6th 2020
3:35 pm:
Speaker: Frank Bates, University of Minnesota (CEMS)
Subject: Diblock Copolymer Melts Mimic Metallurgy
Refreshments in atrium after the Colloquium.

Block copolymers have captured the interest of scientists and engineers for more than half a century. In general, the phase behavior of diblock copolymers, the simplest category of such self-assembling macromolecules, has been accepted as thoroughly understood. Until several years ago, sphere forming diblock copolymers seemed particularly simple, with universal ordering on a body-centered cubic (BCC) lattice as predicted 40 years ago. Experiments with low molecular weight poly(isoprene)-b-poly(lactide) (PI-PLA) diblock copolymer melts have disrupted this picture, revealing remarkable phase complexity in the limit of asymmetric compositions, 0.15 < fL < 0.30, where fL signifies the volume fraction of PLA. Small-angle X-ray scattering (SAXS) measurements conducted in the vicinity of the order-disorder transition have demonstrated the formation of several topologically close-packed Frank-Kasper (FK) phases, including the , C14 and C15 phases, and a dodecagonal quasicrystal (QC), in addition to BCC packing. This lecture will explore the underlying molecular and geometric factors that drive this fascinating complex phase behavior. A central feature is the tendency for self-assembled micelles to be spherical, which is frustrated by the necessity for soft materials to fill space at constant density leading to the formation of space filling polyhedral particles. A surprising analogy will be drawn with the underlying competition between electronic structure and ordered state symmetry that contributes to the formation of FK and QC phases in various metals and alloys. This work highlights extraordinary opportunities for uncovering the principles governing symmetry breaking in soft and hard materials by exploiting the unparalleled control over molecular structure associated with block copolymers.

Faculty Host: Rafael Fernandes

Thursday, February 13th 2020
3:35 pm:
Speaker: Cynthia Keppel, Thomas Jefferson National Accelerator Facility
Subject: Nuclear Science: from Fundamental Physics to Medical Technology
Refreshments in atrium after the Colloquium.

Discoveries and technological advances spurred by the demands of nuclear and particle physics research find applications in many disciplines, including providing benefit to society through the treatment and diagnosis of disease. An overview of the connection between nuclear physics and medicine will be presented, with some emphasis on landmark and recent technological developments. As an example, proton radiation therapy is a precise form of radiation treatment for cancer. Due to the characteristic Bragg peak associated with ion energy deposition, proton therapy provides the radiation oncologist an improved method of treatment localization within a patient, as compared with conventional radiation therapy using X-rays. This can be accomplished only in concert with advances in tumor identification and localization, patient motion and positioning, treatment planning and evaluation, and a host of supporting technologies that can leverage nuclear and particle physics detection and data processing techniques.

Faculty Host: Shaul Hanany

Thursday, February 20th 2020
3:35 pm:
Speaker: Shri Kulkarni, Caltech
Refreshments in atrium after the Colloquium.
Faculty Host: Liliya L.R. Williams

Thursday, February 27th 2020
3:35 pm:
Speaker: Xavier Siemens, University of Wisconsin-Milwaukee
Refreshments in atrium after the Colloquium.
Faculty Host: Vuk Mandic

Thursday, March 5th 2020
3:35 pm:
Speaker: Roger Blandford, Stanford University
Refreshments in atrium after the Colloquium.
Faculty Host: Clement Pryke

Wednesday, March 11th 2020
3:35 pm:
No Colloquium this week, spring break.

Thursday, March 19th 2020
3:35 pm:
Speaker: Ray Orbach, University of Texas at Austin
Refreshments in atrium after the Colloquium.
Faculty Host: E. Dan Dahlberg

Thursday, March 26th 2020
3:35 pm:
Speaker: Tomasz Skwarnicki, Syracuse University
Refreshments in atrium after the Colloquium.
Faculty Host: Mikhail Voloshin

Thursday, April 2nd 2020
3:35 pm:
Speaker: Taekjip Ha, Johns Hopkins University
Refreshments in atrium after the Colloquium.
Faculty Host: Elias Puchner

Thursday, April 16th 2020
3:35 pm:
Speaker: Michael Riordan, University of California Santa Cruz
Refreshments in atrium after the Colloquium.
Faculty Host: Michel Janssen

Thursday, April 23rd 2020
3:35 pm:
Speaker: Liang Fu, MIT
Student Award ceremony before colloquium. Refreshments in atrium after the Colloquium.
Faculty Host: Rafael Fernandes

Thursday, April 30th 2020
Speaker: Robin Canup (Southwest Resarch Institute)
Time will probably shift by 1/2 hour.

Thursday, October 22nd 2020
3:35 pm:
Speaker: Rai Weiss, MIT.
Refreshments in atrium after the Colloquium.

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