30th October 2020 at 14.15: Joonas Nättilä

For our first Physics Colloquium of the new academic year, we will have a presentation to be given by Joonas Nättilä. In his colloquium, entitled Astrophysical turbulence: from stirring coffee to illuminating black holes, Joonas will give an overview on how supercomputer simulations can help shed new light on astrophysical turbulence.

Joonas Nättilä is a postdoctoral research scientist at Columbia University and a Flatiron Research Fellow at the Flatiron Institute’s Center for Computational Astrophysics in New York, USA. His research interests lie in high-energy astrophysics and plasma physics, focusing particularly on modelling the physics of neutron stars.

The event will be held on Friday 30.10.20 at 14:15, on the following University Zoom meeting:

Here is his abstract:

Turbulence – the seemingly chaotic flow of fluids and plasmas – is said to be one of the most important unsolved problems of contemporary physics and mathematics. It is a ubiquitous physical phenomenon operating in all kinds of environments, from mixing liquids in coffee cups to energizing astrophysical plasmas around black holes and neutron stars. In my talk, I will review some of the latest insights we have gained in understanding astrophysical turbulence from first principles by utilizing new state-of-the-art particle-in-cell supercomputer simulations.

In the spirit of our usual cocktail reception, we encourage all attendees to join us with a glass of your favourite tipple. Cheers!



13th December 2019 at 14.15 in E204: Filip Tuomisto

Our last colloquium of the Fall 2019 season will be another inaugural lecture by a new professor in our department, Filip Tuomisto.

Filip is Professor of Experimental Materials Physics here in Helsinki. In his research, he focuses on the development and applications of positron annihilation spectroscopy for studying the atomic-scale structures of materials for future technologies.

In his presentation, titled Antimatter: does it matter? Filip will tell us about the use of positrons in probing the structure of matter and in medical imaging.

Here is the abstract of his talk:

The fundamental question in materials science is: Why is matter what it is? More precisely, if one takes a piece of some material, why does it look what it looks like, why does it respond to external electromagnetic fields in the way it does, why does it yield in the way it does when a force is applied? Many other similar questions can be thought of. In all simplicity, all these properties are dictated by the identities of the atoms constituting the material, and their positions in space. In practice, however, a macroscopic amount of material contains by far too many atoms in order to address the issue atom-by-atom. A wide variety of experimental methods has been developed for studying the atomic-level structure of matter, most of them based on shooting something (electromagnetic waves, particles) at a piece of material, and then observing what (electromagnetic waves, particles) comes out and how. In addition to light, electrons and ions, the probing can be performed also using antimatter. Positrons can be injected into matter, and the positron-electron annihilation gamma radiation analyzed, giving various kinds of information on the local environment of the positron at the time of its demise. In this colloquium, I will give a short introduction to the utilization of positrons in materials science and medical imaging. Antimatter may indeed matter.

After the 30 minute talk, there will be a cocktail reception. Welcome!

1st November 2019 at 14:15 in Exactum B123: Minna Huotilainen

Our next colloquium will take place on 1st November 2019.  Our speaker will be Professor Minna Huotilainen, from the Cognitive Brain Research Unit of the University of Helsinki.  She is a researcher in psychology and cognitive science, working in particular on the development of human cognition. Her research interests include for example the role of music and sounds on brain development, and how to optimise brain work and its recovery. She is the author of a popular science book on brain research and its applications to education and learning, Näin aivot oppivat.

In her talk, titled Can brain research be helpful in advancing physics – optimising scientific work, she will tell us about brain health and how to improve it. Here is her abstract:

Neuroscience is advancing in its technologies and also research methods, allowing more applied questions to be addressed with brain research. One interesting field to scientists is optimising scientific work, aiming at the wellbeing of the brain in the long term as well as high functionality in the work context both for cognitive capabilities as well as for creativity. This talk reviews some of the major findings in this field, allowing the audience to develop their own work and recovery habits.

After the 30 minute talk, there will be a cocktail reception. Welcome!

12th April 2019 at 14.15 in D101: Pauline Gagnon

Image credit: CERN

Our next colloquium will be held on 12th April. The speaker will be Pauline Gagnon,  retired Senior Research Scientist in particle physics from Indiana University and popular science writer.

Pauline Gagnon has conducted most of her research career at CERN, searching for dark matter particles. She has also contributed to the construction of a tracking device for the ATLAS detector.  She is strongly involved in science communication to the general public, and is the author of a popular science book on particle physics: Who Cares about Particle Physics: Making Sense of the Higgs boson, the LHC and CERN. In the recent years, she has been giving numerous public talks about diversity issues in physics.

In her presentation, titled The tragic destiny of Mileva Marić Einstein, she will tell us more about the little-known story of a hidden female figure in physics history.

Here is the abstract of her talk:

What were Albert Einstein’s first wife’s contributions to his extraordinary productivity in the first years of his career? A first biography of Mileva Marić Einstein was published in Serbian in 1969 but remained largely unknown despite being translated first in German, then in French in the 1990’s. The publication of Mileva and Albert’s love letters in 1987 revealed how they lived together while two recent publications shed more light on Mileva Marić’s life and work. I will review this evidence in its social and historical context to give a better idea of her contributions. In this presentation, I avoid all type of speculation and do not attack Albert Einstein personally, but rather strictly stick to facts. The audience will be able to appreciate why such a talented physicist has been so unkindly treated by history.

After the 30 minute talk, there will be a cocktail reception. Welcome!

8th February 2019 at 14.15 in D101: Peter Johansson

Our next colloquium will be held on 8th February. Our next talk is an inaugural lecture by another new professor in our department, Peter Johansson.

Peter is Professor of Astrophysics here in Helsinki. His research interests range from supermassive black holes to galaxy evolution. He recently received an ERC Consolidator Grant to study the dynamics of supermassive black holes in galactic-scale hydrodynamical simulations and estimate their gravitational wave signatures.

In his talk, titled The birth, life and death of astrophysical black holes, he will discuss exactly those topics.

Here is the abstract of his talk:

Black holes are an important component of the Universe. Stellar-mass black holes are found in abundance throughout galaxies, whereas supermassive black holes reside in the centres of galaxies. In this presentation I will discuss the formation and evolution of different types of black holes and what impact they have on the surrounding galaxy. I will also discuss how black holes and their immediate surroundings can be observed using both electromagnetic and gravitational wave signals. The presentation will be rounded off by a discussion on what is going to happen to black holes in the very distant future and whether they will exist forever.

After the 30 minute talk, there will be a cocktail reception. Welcome!