Jean Heidmann – författare

The extragalactic universe, the immense world of a billion galaxies lying beyond out own, is the subject of this book. Our Sun is but a tiny star among a hundred billion other in our Galaxy, the Milky Way, which appears as a luminous veil trailing across the clear night sky. Beyond the Milky Way we will soar into space amid galaxies, clusters of galaxies, radio galaxies and quasars of enormous energy, out to the cosmological horizon which arrests our flight like an intangible barrier. Why do galaxies seem to fly from us? Is space so strongly curved that by going straight ahead we come up behind ourselves? Did it all begin with an enormous explosion, the famous Big Bang, which decided our fate in the first quarter of an hour? These are the questions which this rigourous and enthusiastic scientist tries to answer with complete honesty and non-technical clarity.

The immensity of the cosmos, the richness of the Universe, the limits of space and time: these are the themes of Cosmic Odyssey, which takes the reader on imaginary journeys through the past, present and future of our universe.

Des signaux artificiels venus d''ailleurs balaient-ils notre Terre ? En tentant de les capter, apprendrons-nous que nous ne sommes pas seuls dans l''univers ? Les explorateurs d''aujourd''hui traquent les messages radio de l''univers derrière leurs télescopes géants. Et notre génération est désormais capable d''entrer en communication avec l''« autre » par-delà les espaces intersidéraux. Jean Heidmann, astronome à l''Observatoire de Paris, est membre du comité SETI de l''Académie internationale d''astronautique.

This book collects together a selection of the best paperspresented at the Third International Bioastronomy Symposiumheld in 1990. The subject is bioastronomy, the search forlife in the universe, andthe book is devided according tothe five main stages of life as recognized by this newbranch of science: cosmic organic, prebiotic, primitivebiological, and advanced. Thereader will find here the mostrecent results obtained by top specialists from all over theworld on hot topics such as the formation and discovery ofplanets, organic chemistry in meteorites and comets,prebiotic chemistry in the atmosphere of Titan, the searchfor primitive life in the permafrost of Mars, and, SETIitself, the search for extraterrestrial intelligence.Complemented by live discussions each presentation formsa review of the state-of-the-art treatment of a particulararea and also looks toward those developments inbioastronomywhich will surely be realized in the next fewyears.