Résumé / Abstract Seminaire_IAP
« On the Drake equation, the Fermi paradox and the Galactic habitable zone »

Nikos Prantzos
Institut d'Astrophysique de Paris (Paris, France)

I will discuss three different topics related to extraterrestrial life. The Drake equation and the Fermi paradox are now more than fifty years old and have largely contributed to the general discussion on intelligent life in the Universe. I will present a unified framework for a joint analysis of those topics, which enables for the first time a simultaneous, quantitative study of both of them. It appears that for
sufficiently long-lived civilizations, colonization of the Galaxy is the only reasonable option to gain
knowledge about other life forms. This argument allows one to define a region in the parameter space of the Drake equation where the Fermi paradox definitely holds ("Strong Fermi paradox"). I will also discuss the concept of Galactic Habitable Zone (GHZ) which was introduced about fifteen years ago as an extension of the older concept of Circumstellar Habitable Zone. However, the physical processes underlying the concept of GHZ are hard to identify and even harder to quantify. This makes it difficult at present to draw any conclusions on the validity or the importance of that concept.
vendredi 27 février 2015 - 11:00
Amphithéâtre Henri Mineur, Institut d'Astrophysique de Paris
Page web du séminaire / Seminar's webpage