Alain Picard 
IN SHORT Gamma bursts: among the most powerful explosions in the universe. Result from the collapse of massive stars into black holes. Produce jets of radiation with high energy. Violent events: kilonovas and hypernovas. Recent observations thanks to the James Webb telescope. Contribute to the understanding of cosmic formation. Potential danger to Earth, despite the … Read more
IN BRIEF Galactic magnetic fields: possibility of accelerating cosmic rays. Interplanetary magnetic field: values between 10−10 and 10−8 T. Impact of solar wind on the magnetic field. Cosmic magnetic fields influence the structure of stars and galaxies. Variations in the magnetic field of stars: information about their geometry. Study of magnetic fields is crucial for … Read more
IN BRIEF Reexamination of fundamental notions: substance, time, causality. Study of the concepts of evolution regarding the universe and societies. Analysis of the foundations and methods of philosophy of science. Questioning the value and consequences of scientific research. Exploration of the philosophical and spiritual implications of modern physics. Cosmology as a physical system raising philosophical … Read more
IN BRIEF Pulsar: a dense neutron star rotating rapidly Emits electromagnetic radiation like a beacon Radiation linked to its magnetic field and rotation Beam of radio waves sweeps space Interval between pulses varies, typically per second Pulsars can exist in binary systems Ability to recycle itself by absorbing mass from a companion star Gamma pulsars … Read more
IN BRIEF Exploration of the solar system: impact on scientific thinking Discovery of Neptune by Urbain le Verrier in 1846 Comprehensive overview of planets, moons, and other celestial bodies by Peter Bond Role of probes and spacecraft in understanding our system Importance of observation tools: telescopes and remote-controlled probes Rapid evolution of exploration in the … Read more
IN BRIEF Origin of galaxies: results from small fluctuations in density in the primitive universe. Formation: process by merging dwarf galaxies and gravitational collapse. Types of galaxies: include spiral galaxies, with a disk of gas, dust, and stars. Evolution: linked to each galaxy’s ability to create stars. Environment: evolution depends on local physical and chemical … Read more
IN BRIEF Critical density : key value characterizing the energy of the Universe. Relationship between the density of the Universe and its curvature. Impact of a density lower than critical density: eternal expansion. Consequences of a density higher : possibility of a Big Crunch. Standard cosmological model based on general relativity. Measurement of critical density: … Read more
IN BRIEF Cosmic filaments: thread-like structures made up of galaxies and galaxy clusters. Comprise the cosmic web, a complex network of empty spaces surrounded by walls of matter. Filaments can extend for hundreds of millions of light-years. First observed, they reveal the largest cosmic structures in rotation. Organize the matter of the Universe on a … Read more
IN SHORT The interaction between galaxies results from the gravitational field of other galaxies. Galactic collisions generate instabilities promoting the formation of spiral arms. Following a merger, stars ignite, and supermassive black holes activate. These events cause superwinds and cosmic chaos, but not total disaster. Many galaxies have already experienced interactions in their history. The … Read more
IN BRIEF Earth observation satellites: tools for geophysical and geographical data. Remote sensing: modern technique for monitoring the planet. TILBA® laser communication: receiving data at very high speeds. Instantaneous observation: covering large areas in seconds. Varied missions: from crop inventory to volcanic studies. Geostationary orbits: constant monitoring of the same region. Multiple applications: navigation, communications, … Read more