Good surprise and nostalgia! The legacy of major scientists, such as the astrophysicist Hubert Reeves and the paleoanthropologist Yves Coppens, provides keys to the future of research, an optimistic observation made during tributes that are anything but conventional to these two missing figures. Their discoveries open the way to new and more fundamental research, note their colleagues. As proof, this idea expressed on October 18 at the CNRS, of a return to studies devoted to cosmic deuterium, 13.8 billion years old, carried out more than fifty years ago by the author of Stardust.
Working on the early stages of the big bang, Hubert Reeves then devoted himself to the study of this heavy hydrogen (in addition to a proton, its nucleus has a neutron) which is used in nuclear fusion reactors such as ITER, dream of a sun artificial, the Holy Grail in the conquest of energy ad vitam aeternam… Cosmic deuterium has the virtue of being a formidable indicator. Its quantity makes it possible to determine one of the most fundamental data of the Universe: the relationship between ordinary matter – that of the atoms, planets and galaxies that we know – and the matter of the entire Universe. A prime guide to “dark matter” which has so far escaped detection.
What proposal do astrophysicists make? Return to the first measurements published in 1972 by Reeves and Johannes Geiss (former director of the International Space Science Institute in Bern), carried out in a brilliant way thanks to a detector made of mica sheets, placed on the Moon by the astronauts of Apollo, in order to analyze the solar wind. NASA had helped, the very powerful James-Webb telescope can today take up the torch of cosmic deuterium.
Back on earth, direction Ethiopia, on the Hadar site, and questions… of adaptation to the climate and the environment. On November 16 at the Musée de l'Homme, the fiftieth anniversary of the discovery in 1974 of Lucy the Australopithecus, 3.2 million years old – which “owes his fame in France to Yves Coppens”, underlines Raymonde Bonnefille, author of In Lucy's footsteps (Ed. Odile Jacob), member of the International Afar Research Expedition at the time.
-Then a specialist in pollens (more than 50,000 collected), the scientist now judges that“much remains to be elucidated about the landscapes” surveyed by the Australopithecus afarensis. Because the species has survived no less than 900,000 years, three times longer than us, the A wise man… Enough to wonder about the reasons for its “success”, about its ability to go through periods during which the climate and environment varied, a question that fascinated Coppens. Note, it is to this Pliocene period that we must go back to find a high percentage of CO2 in the atmosphere, comparable to that of today. Enough to challenge scientists, and not just anthropologists.
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