Konwersatorium im. Jerzego Pniewskiego i Leopolda Infelda
2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024
Informacje na temat wcześniejszych spotkań dostępne są tutaj:
2021-06-07 (Poniedziałek)
Zapraszamy do sali 0.03, ul. Pasteura 5 o godzinie 16:30 
Prof. dr Grzegorz Pietrzyński (Centrum Astronomiczne im. Mikołaja Kopernika PAN)"Precise determination of the cosmic distances and the Universe’s expansion mysteries"
After the detection of the accelerated expansion of the Universe (Nobel prize 2011) and the introduction of an enigmatic “dark energy” component of the matter-energy content of the Universe the physical explanation of the nature of dark energy has become a major challenge for astronomers and physicists. The recent empirical determinations of the Universe expansion based on standard candles (Cepheids, Supernovae Ia) complicated even more our understanding of the Universe since they differ by about 4σ from the value obtained from Planck data and the ΛCDM model, which suggest that new physics might be required in the models. However before one can claim the revision in modern physics all systematic errors affected the determination of the expansion rate must be very carefully investigated and accuracy, and not only precision must be reached.
In my presentation I will discuss the most precise and accurate methods for cosmic distance determinations. I will also explain how these methods can be used to calibrate other long-range distance indicators, which allow us to calibrate Supernovae Ia. Finally I will discuss how accurately we expect to determine the expansion rate of the Universe in the near future, and how this will impact the current discrepancy between different values of the expansion rate of the Universe as obtained with different techniques.
Pobierz nagranie / Download the recording
In my presentation I will discuss the most precise and accurate methods for cosmic distance determinations. I will also explain how these methods can be used to calibrate other long-range distance indicators, which allow us to calibrate Supernovae Ia. Finally I will discuss how accurately we expect to determine the expansion rate of the Universe in the near future, and how this will impact the current discrepancy between different values of the expansion rate of the Universe as obtained with different techniques.
Pobierz nagranie / Download the recording
2021-04-26 (Poniedziałek)
Zapraszamy do sali 0.03, ul. Pasteura 5 o godzinie 16:30
Dr Brendan Kiburg, Fermilab and Prof. Dominik Stoeckinger, TU DresdenFirst results from the Muon g-2 experiment at Fermilab and theory predictions and interpretations
Dr Brendan Kiburg (Fermilab): First results from the Muon g-2 experiment at Fermilab
The Muon g-2 Experiment recently reported a new measurement of the anomalous magnetic moment of the muon with a precision of 0.46 parts-per-million. This result is in good agreement with the previous experimental measurement from Brookhaven National Laboratory and has increased the tension with the Standard Model calculation to 4.2 standard deviations, strengthening hints of New Physics. This talk will give a brief description of the experimental history and will provide an overview of the measurement challenges and analysis techniques.
Pobierz prezentację / Download the slides
Prof. Dominik Stoeckinger (TU Dresden): Theory predictions and interpretations of the Fermilab g-2 result.
The quantity g-2 of the muon is sensitive to all known elementary particles and all forces between them. In the Standard Model of particle physics a highly precise prediction is possible. The observed deviation from the Standard Model might be due to additional, so far unknown particles or forces. The talk will briefly explain the status of the Standard Model prediction and give an overview of potential implications for physics beyond the Standard Model.
Pobierz prezentację / Download the slides
Pobierz nagranie (brak pierwszych 2 minut) / Download the recording (delayed by 2 mins)
2021-03-29 (Poniedziałek)
Zapraszamy do sali 0.03, ul. Pasteura 5 o godzinie 16:30
Aleksandra Kardaś (Wydział Fizyki UW)Climate change - which way forward?
Global climate change introduces vast changes in environmental conditions all around the world. Changing weather patterns and the rising sea level make life harder for all beings accustomed to specific local conditions. The change is happening very quickly, which makes adaptation difficult and expensive, in some cases impossible. To limit the costs, we should stop the warming as soon as possible. What actions need to be taken? We will discuss these issues in the context of the Intergovernmental Panel on Climate Change special report „Global Warming of 1,5°C”.
Pobierz plakat / Download the poster
Pobierz nagranie / Download the recording
2021-01-25 (Poniedziałek)
Zapraszamy do sali 0.03, ul. Pasteura 5 o godzinie 16:30
Prof. dr Tomasz Lipniacki (Instytut Podstawowych Problemów Techniki PAN)SARS CoV 2 super-spreaders and super-spreading Variant of Concern 202012/01
The basic reproduction number R0 of the coronavirus disease 2019 has been estimated to range between 2 and 4. We used an SEIR model that properly accounts for the distribution of the latent period and, based on empirical estimates of the doubling time in the near-exponential phases of epidemic progression in China, Italy, Spain, France, UK, Germany, Switzerland and New York State, we estimated that R0 lies in the range 4.7–11.4. We explained this discrepancy by performing stochastic simulations of model dynamics in a population with a small proportion of super-spreaders.
The novel SARS-CoV-2 Variant of Concern (VOC)-202012/01 (also known as B.1.1.7), first collected on September 20, 2020, in Kent, UK, is a rapidly growing lineage. Based on GISAID we estimated that the replicative advantage of the VOC-202012/01 lineage is in the range of 1.85–2.17 with respect to the 20A.EU1 variant (dominating in England in November 2020) and in the range of 1.99–2.36 with respect to other non-VOC-202012/01 strains. Such significant replicative advantage and the fact that London serves as major international transportation hub suggest that the VOC-202012/01 strain will likely become globally dominant, hindering containment of the COVID-19 epidemics prior to mass vaccinations.
The novel SARS-CoV-2 Variant of Concern (VOC)-202012/01 (also known as B.1.1.7), first collected on September 20, 2020, in Kent, UK, is a rapidly growing lineage. Based on GISAID we estimated that the replicative advantage of the VOC-202012/01 lineage is in the range of 1.85–2.17 with respect to the 20A.EU1 variant (dominating in England in November 2020) and in the range of 1.99–2.36 with respect to other non-VOC-202012/01 strains. Such significant replicative advantage and the fact that London serves as major international transportation hub suggest that the VOC-202012/01 strain will likely become globally dominant, hindering containment of the COVID-19 epidemics prior to mass vaccinations.
https://doi.org/10.1098/rsos.200786
https://doi.org/10.1101/2020.12.28.20248906
The colloquium will take place via ZOOM. For the parameters, see the October 26, 2020 lecture.
2020-12-21 (Poniedziałek)
Zapraszamy do sali 0.03, ul. Pasteura 5 o godzinie 16:30
dr Anna Karnkowska oraz dr Dorota Skowron (Wydział Biologii UW; Obserwatorium Astronomiczne UW)Lectures by the two (ex aequo) laureates of the 2020 Marek Pieńkowski Scientific Prize
Exploring microbial diversity to understand the evolution of eukaryotic cell
The emergence of eukaryotes, cells with organelles such as nucleus and mitochondria or plastids, had a revolutionary impact on the subsequent history of life, leading to the evolution of complex multicellular organisms. I will discuss the endosymbiotic origin of mitochondria and plastids from bacteria, and their subsequent evolution. Finally, I will focus on our discovery of a unicellular organism Monocercomonoides, the first known eukaryote with no mitochondrion. Investigation of Monocercomonoides allowed us to understand how endosymbiosis can be undone and how this affects the cellular complexity.
Pobierz prezentację dr Anny Karnkowskiej / Download the presentation of dr Anna Karnkowska
A three-dimensional map of the Milky Way based on classical Cepheids
We know that the Milky Way is a spiral galaxy, but methods used to describe it in more detail have been indirect and based on various assumptions. This, combined with the fact that we live within the disk and observe it through clouds of gas and dust, makes it very difficult to make a precise map of our Galaxy. However, there is a class of young variable supergiant stars, called classical Cepheids, to which we can measure distances with a great accuracy. I will show how we used a large sample of these stars to create a new, detailed map of the Milky Way in three dimensions, and what they can tell us about the recent history of our Galaxy.
Pobierz prezentację dr Doroty Skowron / Download the presentation of dr Dorota Skowron [.odp]
Pobierz prezentację dr Doroty Skowron / Download the presentation of dr Dorota Skowron [.pdf]
The colloquium will take place via ZOOM. For the parameters, see the October 26, 2020 lecture.
Pobierz plakat / Download the poster
The emergence of eukaryotes, cells with organelles such as nucleus and mitochondria or plastids, had a revolutionary impact on the subsequent history of life, leading to the evolution of complex multicellular organisms. I will discuss the endosymbiotic origin of mitochondria and plastids from bacteria, and their subsequent evolution. Finally, I will focus on our discovery of a unicellular organism Monocercomonoides, the first known eukaryote with no mitochondrion. Investigation of Monocercomonoides allowed us to understand how endosymbiosis can be undone and how this affects the cellular complexity.
Pobierz prezentację dr Anny Karnkowskiej / Download the presentation of dr Anna Karnkowska
A three-dimensional map of the Milky Way based on classical Cepheids
We know that the Milky Way is a spiral galaxy, but methods used to describe it in more detail have been indirect and based on various assumptions. This, combined with the fact that we live within the disk and observe it through clouds of gas and dust, makes it very difficult to make a precise map of our Galaxy. However, there is a class of young variable supergiant stars, called classical Cepheids, to which we can measure distances with a great accuracy. I will show how we used a large sample of these stars to create a new, detailed map of the Milky Way in three dimensions, and what they can tell us about the recent history of our Galaxy.
Pobierz prezentację dr Doroty Skowron / Download the presentation of dr Dorota Skowron [.odp]
Pobierz prezentację dr Doroty Skowron / Download the presentation of dr Dorota Skowron [.pdf]
The colloquium will take place via ZOOM. For the parameters, see the October 26, 2020 lecture.
Pobierz plakat / Download the poster
2020-11-23 (Poniedziałek)
Zapraszamy na spotkanie o godzinie 16:30
Prof. Jerzy Lewandowski i dr hab Łukasz Wyrzykowski (Wydział Fizyki UW)The 2020 Nobel Prize in Physics
The 2020 Nobel Prize in Physics has been awarded to Sir Roger Penrose (half of the Prize), Reinhard Genzel and Andrea Ghez (jointly, the other half of the Prize) for their work on black holes. Sir Roger Penrose received the award “for the discovery that black hole formation is a robust prediction of the general theory of relativity". To this end, he used innovative methods of space-time geometry, which he partially created and developed himself. Importantly for the audience of our Faculty, Penrose employed the geometry of null geodesics used earlier in general relativity by Ivor Robinson and Andrzej Trautman. The methods and results will be presented by prof. Jerzy Lewandowski from the Faculty of Physics, University of Warsaw.
Experimentalists Reinhard Genzel and Andrea Ghez have been prized for their observations of the Centre of the Galaxy and for proving the existence of a massive compact object there. Methodology and results of the two groups led by Genzel and Ghez will be presented and consequences and future of such studies will be discussed by dr hab. Łukasz Wyrzykowski from the Astronomical Observatory, Faculty of Physics, University of Warsaw.
The colloquium will take place via ZOOM. For the parameters, see the October 26, 2020 lecture.
Pobierz plakat / Download the poster
Pobierz prezentację prof. Lewandowskiego/ Download the presentation of prof. Lewandowski
Pobierz prezentację dr hab. Wyrzykowskiego/ Download the presentation of dr hab. Wyrzykowski
Experimentalists Reinhard Genzel and Andrea Ghez have been prized for their observations of the Centre of the Galaxy and for proving the existence of a massive compact object there. Methodology and results of the two groups led by Genzel and Ghez will be presented and consequences and future of such studies will be discussed by dr hab. Łukasz Wyrzykowski from the Astronomical Observatory, Faculty of Physics, University of Warsaw.
The colloquium will take place via ZOOM. For the parameters, see the October 26, 2020 lecture.
Pobierz plakat / Download the poster
Pobierz prezentację prof. Lewandowskiego/ Download the presentation of prof. Lewandowski
Pobierz prezentację dr hab. Wyrzykowskiego/ Download the presentation of dr hab. Wyrzykowski
2020-10-26 (Poniedziałek)
Zapraszamy na spotkanie o godzinie 16:30
dr Janusz Pętkowski (Massachusetts Institute of Technology)The search for life as we (do not) know it
For thousands of years, inspired by the star-filled dark night sky, people have wondered what lies beyond Earth. Today, the search for signs of life is a key factor in modern-day planetary exploration, both for in situ exploration of our own Solar System's planets and moons and for remote sensing via telescopes of exoplanets orbiting nearby stars. However, the search for life outside Earth is not a trivial task. We aim to detect gases in planetary atmospheres that might be attributed to life by means of transmission spectroscopy. A suitable "biosignature gas" must: be able to accumulate in an atmosphere against atmospheric radicals and other sinks; have strong atmospheric spectral features; and have limited a biological false positives. But how do we know what signs of life to look for? A fundamental goal of biology is to understand the rules behind life's use of chemistry. We do not know how chemically diverse life really can be. Can life be so chemically different from life on Earth that it uses entirely different chemical building blocks, or even solvents different than water? In my talk we will discuss these possibilities. We will conclude the discussion by trying to put the recent discovery of phosphine in the clouds of Venus in a broader astrobiological context.
Pobierz plakat / Download the poster
Pobierz prezentację / Download the presentation
The colloquium will take place via ZOOM
https://us02web.zoom.us/j/93881687598?pwd=UmFhVUdVSXhnQ2tIVVozNmowSUNtZz09
Meeting ID: 938 8168 7598
Passcode: prv316.
If you do not have ZOOM installed, after clicking the link the browser will show the page "Launch Meeting". Let the page open the zoom.us application, then click "cancel". You will see an option "Join from your browser", then show that "you are not a robot", type your name, and then you are connected!
Pobierz plakat / Download the poster
Pobierz prezentację / Download the presentation
Pobierz nagranie / Download the recording
The colloquium will take place via ZOOM
https://us02web.zoom.us/j/93881687598?pwd=UmFhVUdVSXhnQ2tIVVozNmowSUNtZz09
Meeting ID: 938 8168 7598
Passcode: prv316.
If you do not have ZOOM installed, after clicking the link the browser will show the page "Launch Meeting". Let the page open the zoom.us application, then click "cancel". You will see an option "Join from your browser", then show that "you are not a robot", type your name, and then you are connected!