Seminars

Wednesday Colloquium

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The Colloquium takes place every Wednesday at 11:15 AM - Warsaw Copernicus Astronomical Centre online by means of Zoom platform. The Colloquium is given in English and chaired by dr Stanisław Bajtlik (bajtlik@camk.edu.pl)People from outside of the Copernicus Center are very welcome to participate. For technical detailes please contact Dr. Stanislaw Bajtlik.



09.02.2022

"Stability-Causality Theorems"

Lorenzo Gavassino (CAMK, Warsaw)

Relativistic hydrodynamics is tricky. There are pitfalls at every corner. Many authoritative textbooks, which are currently used as standard references both in physics and astronomy, present several hydrodynamic equations that lead to completely unphysical predictions (e.g., a glass of water should spontaneously detonate in 10^-34 seconds!). Among such books, we find Novikov-Thorne ("Astrophysics of black holes"), Misner-Thorne-Wheeler ("Gravitation"), Mihalas-Mihalas ("Foundations of radiation hydrodynamics"), and many others. Hence, it is not surprising that such incorrect equations have become part of the "common sense" of a considerable fraction of the astrophysical community, being used both in theoretical models and numerical simulations. How bad is the situation? For decades, some of the brightest minds (e.g. Carter, Israel, Lindblom, Geroch, Anile, Ruggeri) have been looking for more reliable equations, but nobody ever analyzed the problem in full generality. What makes a theory problematic? What makes a theory reliable? What happens if we simulate the wrong theory? Is there an intuitive explanation for all of this? I will provide the definitive answer to all these questions, and I will do it without writing a single equation.


 


Special seminars

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Journal Club

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Journal Club takes place on Mondays at 11:10 AM in the Barek room. The seminar is given in English and is chaired by Jonas Pereira.



 


The Bohdan Paczyński Memorial Colloquium

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GeoPlanet Seminars

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