le 5 septembre 2025, 10h45 à 12h45, Arturo Lopez-Ariste, salle Lyot, OMP, site Belin Summary: The phase of a wave can only be defined unambiguously for complex waves. This strange quantity appears at the core of all physics: from the quantification of atomic levels or of the electric charge to the source of the electromagnetic […]
le 12 septembre 2025, 10h45 à 12h45, Katia Ferrière, salle Lyot, OMP, site Belin Summary: I will take you on a cosmic journey from the Earth to the far reaches of the observable Universe. We will first spend some time in the solar system, where I will show how the radius of the Earth and […]
Le 19 septembre 2025, Luigi Tibaldo, 10h45 à 11h45, Salle Jules Verne, OMP, site Belin Summary: Cosmic rays are energetic particles first observed around the Earth with energies ranging from MeV to above 10^20 eV and with approximately isotropic arrival directions. A most remarkable change of the cosmic-ray spectrum occurs around 10^15 eV. Below this […]
Le 19 septembre 2025, Luigi Tibaldo, 11h45 à 12h45, Salle Jules Verne, OMP, site Belin Summary: The fundamental laws of physics known to date suggest that equal amounts of matter and antimatter should have been produced, and annihilated, during the Big Bang. Yet, cosmic-ray measurements and gamma-ray observations show that antimatter is present at most […]
Le 26 septembre 2025, Alain Blanchard, 10h45 à 12h45, Salle Jules Verne, OMP, site Belin Summary: Over the course of the twentieth century, cosmology revealed the presence of an unknown form of matter, undetectable on Earth or in laboratories: dark matter, which in fact constitutes the main material component of the Universe. But over the […]
Le 3 octobre 2025, Sylvie Vauclair, 10h45 à 12h45, Salle Jules Verne, OMP, site Belin Summary: Since the beginning of the 20th century, the scientific knowledge on the formation of the chemical elements in the Universe, from Big-Bang to Earth, have evolved in spectacular manner, thanks to close interconnections between atomic physics, « sub-atomic » and then […]
Le 10 octobre 2025, Charlotte Géhan, 10h45 à 12h45, Salle Jules Verne, OMP, site Belin Summary: The advent of ultra-high photometry space missions has revolutionized our understanding of the physical processes governing stellar evolution by enabling to directly probe stellar interiors through asteroseismology. CoRoT and Kepler have provided outstanding results for thousands of pulsating stars, […]
Le 17 octobre 2025, Victor Réville, 10h45 à 12h45, Salle Jules Verne, OMP, site Belin Summary: Magnetic reconnection is a fundamental process in astrophysics. It allows converting magnetic into thermal and kinetic energy in astrophysical plasmas. In the solar atmosphere, it has been associated with solar storms, flares, and the release of energetic particles and […]
Le 7 novembre 2025, Christine Joblin & Hassan Sabbah, 10h45 à 12h45, Salle Jules Verne, OMP, site Belin Summary: With the groundbreaking infrared capabilities of the James Webb Space Telescope, we can now observe the emission from polycyclic aromatic hydrocarbons (PAHs) with unprecedented precision in star- and planet-forming regions. In parallel, sample return missions are […]