The Friday Physics Colloquia at the Department of Physics are open to all. An important goal for the colloquia is to be a meeting place between faculty and students to learn about interesting developments in physics.

Undergraduate students are especially encouraged to attend. Speakers are asked to keep the talks at a level targeting a master student in physics.

Spring 2023 schedule
 

May 26th @ 14:15-15:00 in R10 (D5-171)

Speaker: Prof. Daan Frenkel, Department of Chemistry, University of Chemistry, Cambridge, UK. 

Title: Trying to catch up with Gibbs: How simulators run into problems that Gibbs had already solved.

Host: Raffaela Cabriolu, Materials Theory group at the Materials Physics section, IFY

Abstract: In 1990, the historian Martin Klein wrote an article about J. Willard Gibbs that contains the following passage:
In 1892 Rayleigh wrote to Gibbs urging him to expand on his ideas [DF: formulated in: “On the Equilibrium of Heterogeneous Substances – 1876/1878], saying that the original memoir was "too condensed and too difficult for most, I might say all, readers." Gibbs's answer strikes an unexpected note: He now thought that his memoir seemed "too long" and showed a lack of a "sense of the value of time, of my own or others, when I wrote it."

Shortly before his death, however, Gibbs did agree to a republication of his writings on thermodynamics, to which he planned to add some new material in the form of supplementary chapters. […] Unfortunately we have only the bare titles, "On Similarity in Thermodynamics" and "On Entropy as Mixed-up-ness," and we shall never know what Gibbs planned to write on either subject.

In my talk, I will discuss some aspects of colloidal crystal nucleation, illustrating that one ignores Gibbs at ones peril. 

Come earlier and enjoy a slice of pizza from 14.00 in D5-175

May 12th @ 14:15-15:00 in R10 (D5-171)

Speaker: Prof. Dmitry Chernyshov, Swiss-Norwegian Beamlines at ESRF, Grenoble, France. 

Title: Mapping and control of ferroelectric and anti-ferroelectric domains with in-situ single crystal diffraction of synchrotron

Host: Ragnvald Mathiesen, Porous Media Physics group, IFY

Abstract: Diffraction experiments for mapping of domains in ferroelectric and antiferroelectric crystals are presented and discussed. Dedicated in-situ sample cells allow probing structural evolution as a function of electric field, temperature, and strain. Diffraction data reveal a clear picture of domain configurations via Bragg reflection pattern while, via diffuse scattering, an information about deviations from the average structure and domain walls becomes available. Among other examples, the main emphasis will be given to the phase transitions in PbZrO3 and Pb(Zr,Ti)O3 crystals (2.4% of Zr), where diffraction experiments helped to develop an effective domain engineering scheme to control anti-ferroelectric domain patterns.

Pizza will be served from 14.00 in D5-175

March 24th @ 14:15-15:00 in R8 (AU1-111)

Speaker: Prof. Sera Markoff, University of Amsterdam, The Netherlands

Title: A tale of two black holes:  Sgr A* and M87*

Host: Manuel Linares, Astrophysics and Particle Physics Group, IFY

Abstract: Black holes are one of the most exotic consequences of Einstein’s General Relativity, yet they are also very common, ranging from stellar remnants up to beasts billions of times more massive than our sun. Despite their reputation as cosmic vacuum cleaners, they actually drive extremely complicated astrophysical systems that can majorly influence their surroundings. Via their powerful outflows in particular, black holes shape the way the Universe looks today...but not at all times.

Black holes undergo cycles of activity, so to understand their role over cosmological timescales we need to understand not only how they power these outflows from just outside their event horizons, but also what drives their cyclic behavior. Thanks to the Event Horizon Telescope (EHT) we have now directly imaged the event horizon region for two nearby supermassive black holes: Sgr A* in our own Galactic center, and M87* in the Virgo cluster of galaxies. After a brief review of the key results so far, I will put them into the context of our greater understanding of black hole activity, with emphasis on the gains made by combining EHT observations with those from other multi-wavelength facilities. I will also discuss the near- and longterm outlook for the studies of black hole astrophysics and their cosmic impact.

Pizza will be served from 14.00 in R8 (AU1-111)

March 10th @ 12:30-13:15 in R10 (D5-171)

Speaker:  Prof. Eirik Malinen, Department of Physics, University of Oslo

Title: Norwegian infrastructure for proton therapy research

Host: Kathrine Redalen, Professor and Deputy of research at the Department of physics

Abstract: Norway will have centers for proton therapy of cancer ready in Oslo and Bergen within early 2025. Both centers will have infrastructure for pre-clinical research, and open for experiments in biology, physics, technology and more. The talk will present the coming infrastructures and discuss research opportunities.

Pizza will be served from 12.15 in D5-175

January 13th @ 13:15-14:00 in R10 (D5-171)

Speaker:  Prof. Thomas Tauris, Aalborg University, Denmark

Title: Binary Compact Objects as Gravitational Wave Sources

Host: Manuel Linares, Astrophysics and Particle Physics Group, IFY

Abstract: In the first half of my talk, I will review the nature of gravitational waves: origin, physical characteristics, detection and history. In the second half of my talk, I will give examples of current research investigating the formation, characteristics, and number of binary compact object sources, including a few highlights of close binary star interactions. Finally, I will briefly discuss the future space-borne gravitational wave detector LISA, and also summarize my recent work on the spin orientations of colliding black holes.

Pizza will be served from 13.00 in D5-175