On Thursday, February 25, 2021, at 6:30 p.m., the Science-Actions association invites you to discuss astronomy and astrophysics. The Science Café "Mysteries in the Sky" will be held via videoconference (instructions).
[Watch the web conference replay]
Mysteries in the sky
Observing the sky (astronomy) and explaining the phenomena observed by physics (astrophysics) often confuse our common sense as human beings, because the orders of magnitude and physical laws involved are extraordinarily far removed from what we know in our daily lives as terrestrial bipeds. Furthermore, scientists are unable to explain, at least with today's physical theories, what remain mysteries, for example, to name but a few:
- What is dark energy?
- What is this "missing" and invisible matter, dark matter?
- Where has all the visible matter in our daily lives gone—the elementary particles known as baryons—which we would expect to find in greater quantities throughout the universe?
- Why is the surface of the Sun so hot?
- Why isn't surprising antimatter as widespread in the universe as the matter we know?
- Why does the solar system consist of such different planets?
But knowledge is advancing and attempts to explain these mysteries are being proposed. For example, using recordings of very brief bursts of radio waves (FRBs, or Fast Radio Bursts) coming from space, it has been extrapolated that the space between stars and galaxies contains minute quantities of matter (1 baryon per cubic meter). Could this matter, which has so far escaped our observations due to its rarity, be the much sought-after dark matter? And, for that matter, do we have any idea what is emitting these FRBs with their phenomenal energy? Very recently, the Gran Sasso underground observatory in Italy reported the recording of a signal corresponding to a hypothetical extremely light particle, the axion, which could explain part of the missing dark matter: an extraordinary discovery or a measurement artifact? Even closer to home, observations of the planets in our solar system reveal extraordinary phenomena: for example, the small planet Ceres, which orbits Jupiter, has ice volcanoes on its surface that spew brine, much like lava from Earth's volcanoes.
Come and discuss this topic with experts in the field:
- Damir Buskulic, professor at the University of Savoie Mont Blanc, gravitational waves, LAPP Laboratory (CNRS/USMB), Annecy-le-Vieux
- Elisabeth Maris, president of the Céphée 73 astronomy club, Chambéry
- Gilles Maurin, Senior Lecturer at the University of Savoie Mont Blanc, gamma astronomy, LAPP laboratory (CNRS/USMB), Annecy le Vieux
- Pierre Salati, professor at the University of Savoie Mont Blanc, physicist, astrophysicist, LAPTH laboratory (CNRS/USMB), Annecy le Vieux
- Bernard Schmitt, Director of Research at the CNRS, Planetology, Grenoble Institute of Planetology and Astrophysics
SCIENCE CAFÉS
Science Cafés allow the general public to discuss a variety of topics, often related to current events, with experts, researchers, and professionals in a friendly atmosphere. They are organized by the Science-Actions association, in collaboration with:
- Savoie Mont Blanc University
- the city of Chambéry
- the Astrée cinema
- the Chambéry Youth and Culture Center