Elon Musk’s Mars project is the ultimate symbol of our throwaway culture | Life and style Elon Musk made some rather wild promises at the International Astronautical Congress last week: his SpaceX company is going to start sending people to Mars by 2024, and in 40 to 100 years, he will have a million of us living there. I have one big question about this. Why bother? Mars is a rotten place to live. You can’t breathe, eat, drink or go outdoors; the soil’s toxic, constant radiation streams in from space, and the average temperature is -60C. It looks rather bleak to me, but for some people I suppose the clincher would be that messages home would take 15 minutes, and “it would be hard to Skype with anybody”, according to Ashwin Vasavada of Nasa’s Mars Science Laboratory. But Musk is determined to plough on, make us a “multi-planet species” and turn Mars into “a really nice place to be”. There is being adventurous and curious, and then there is being overambitious, verging on potty.
3 days fasting Des chercheurs d'une équipe de l'Université de Californie du sud (USC) affirment avoir trouvé le moyen de contraindre le corps humain à se régénérer. Une découverte annoncée comme «capitale». Jeûner pendant 72 heures peut permettre de reconstruire l’ensemble du système immunitaire même chez les personnes âgées ou gravement malades telle est la conclusion de cette nouvelle étude scientifique. Si jeûner est considéré comme néfaste pour l’organisme par les nutritionnistes, priver le corps de nourriture pendant trois jours contraindrait ensuite la moelle osseuse à produire de grandes quantités de globules blancs qui combattent les infections. Selon les chercheurs d’USC, jeûner lance un processus de régénération. Les jeûnes prolongés contraignent en fait le corps à consommer ces réserves de glucoses et de graisses mais aussi détruisent une proportion importante des globules blancs.
Gravitational waves: breakthrough discovery after two centuries of expectation | Science Physicists have announced the discovery of gravitational waves, ripples in the fabric of spacetime that were first anticipated by Albert Einstein a century ago. “We have detected gravitational waves. We did it,” said David Reitze, executive director of the Laser Interferometer Gravitational-Wave Observatory (Ligo), at a press conference in Washington. The announcement is the climax of a century of speculation, 50 years of trial and error, and 25 years perfecting a set of instruments so sensitive they could identify a distortion in spacetime a thousandth the diameter of one atomic nucleus across a 4km strip of laserbeam and mirror. The phenomenon detected was the collision of two black holes. At the beginning of the signal, their calculations told them how stars perish: the two objects had begun by circling each other 30 times a second. The observation signals the opening of a new window on to the universe. Thursday’s announcement was the unequivocal first detection ever of gravity waves.
cosmic dawn Astronomers have detected a signal from the first stars as they appeared and illuminated the universe, in observations that have been hailed as “revolutionary”. The faint radio signals suggest the universe was lifted out of total darkness 180m years after the big bang in a momentous transition known as the cosmic dawn. The faint imprint left by the glow of the earliest stars also appears to contain new and unexpected evidence about the existence and nature of dark matter which, if confirmed by independent observatories, would mark a second major breakthrough. “Finding this minuscule signal has opened a new window on the early universe,” said Judd Bowman of Arizona State University, whose team set out to make the detection more than a decade ago. “It’s unlikely we’ll be able to see any earlier into the history of stars in our lifetime.” In practice, detecting this signal has proved hugely challenging, however, and has eluded astronomers for more than a decade.
'A new way to study our universe': what gravitational waves mean for future science | Science You wait 100 years for a gravitational wave and then four come along at once. Or so it must seem to those who spent decades designing and building the exquisite instruments needed to sense the minuscule ripples in spacetime that Albert Einstein foresaw in his 1905 theory of general relativity. The first gravitational wave bagged by physicists reached Earth on 14 September 2015 and sent a quiver through the US-based Laser Interferometer Gravitational-Wave Observatory (Ligo). The second hit three months later, on Boxing Day, followed by a third in January this year. When the fourth wave arrived in August, both Ligo and a second observatory in Italy, named Virgo, recorded the moment. Each of the gravitational waves had been set in motion by violent collisions between black holes more than a billion years ago. “This is a story in two parts,” said Sheila Rowan, director of the Institute for Gravitational Research at the University of Glasgow. Gravitational waves are not so easily blocked.
un cas de chimérisme © Kristin Klein. En temps normal, l'histoire, racontée sur le site Buzzfeed, pourrait n'être que la mise au jour d'un banal cocufiage. Elle commence ainsi : Monsieur et Madame X (ils ont voulu rester anonymes) sont américains et ont un fils, né en juin 2014. Or l'on s'aperçoit que ce dernier est du groupe sanguin AB alors que ses parents sont tous les deux du groupe A. Un test de paternité effectué à partir de cellules de Monsieur X récoltées à l'intérieur de sa joue confirme qu'il n'est pas le père. La conclusion la plus élémentaire conduit à penser qu'à moins qu'il y ait eu un improbable échange d'enfant à la maternité sur le mode La vie est un long fleuve tranquille, Madame X a trompé son mari avec un monsieur qui a fourni le B au bébé. Les résultats sont à tomber par terre. Voici ce qui s'est très probablement passé : dans le ventre de sa mère, Monsieur X avait un faux jumeau – porteur, dans son groupe sanguin, du fameux B dont tout est parti.
Why are astronomers interested in gravitational waves? (Intermediate) - Curious About Astronomy? Ask an Astronomer When you look up at the night sky, you see a very particular view of the Universe. You see electromagnetic radiation, light, at optical wavelengths from objects like stars. If your eyes could see radio waves, which are another wavelength of light, they would see a very different picture of the Universe. The sources of radio light are different than the sources of optical light. Astronomers want to build all different kinds of telescopes to see the entire spectrum of electromagnetic radiation. For almost the entire history of astronomy, we viewed the Universe through an electromagnetic window. On February 11th, 2016, the Laser Interferometer Gravitational-Wave Observatory (LIGO) collaboration announced the detection of gravitational waves from a black hole binary.
quantum supremacy For Google it was a historic announcement: a declaration that it had won the race to achieve “quantum supremacy” – the moment that a futuristic quantum computer performed a task that stumped even the most powerful standard computer in the world. But for all the fanfare, which saw Google’s CEO Sundar Pichai compare the feat to building the first rocket to reach space, the claim has sparked a bunfight. The tech firm’s rival, IBM, was swift to dismiss the excitement. Google has not, it asserts, achieved the highly prized goal of quantum supremacy. Google published its claim in the journal Nature on Wednesday after an earlier report on the work appeared briefly on a Nasa website last month. The paper describes how a team led by John Martinis, leader of the research team working on quantum supremacy, built a superconducting quantum processor named Sycamore that harnesses the weirdness of quantum physics to crunch through thorny problems. Not so, say the IBM researchers.