The scientific news that caught our attention this week.
The American observatory Ligo and the European Virgo, working together, have formalized the detection of four new gravitational waves. This is proportionally a lot, since only six had been recorded and confirmed to date. These four waves of waves were detected in a tight time between July 29 and August 23, 2017. They all come from mergers of black holes – like what, this event must be frequent in the universe if the it is also often discovered by listening attentively.
The wave of July 29, for example, named GW170729, comes from the "The most massive and distant source ever observed for a gravitational wave" it dates from 5 billion years ago. A black hole with a mass of about 51 suns collided with another black hole of 34 solar masses. The fruit of their union is a mega black hole of 80 solar masses. Where did the 5 solar masses lost in the addition go? They have been dissipated in the form of energy, like a shock wave that vibrates the universe and distorts the geometry of space-time in its path. It is this deformation that the Ligo and Virgo interferometers measure … and this one is a record: the nine other waves recorded showed an energy of the order of 1 to 3 suns.
The next season of Ligo and Virgo will begin in the spring of 2019.
To readGravitational waves: "We are only at the beginning"
500 wolves in France, a viable minimum … in the short term
The French population of wolves should exceed 500 individuals by the end of winter, said Thursday the National Office of Hunting and Wildlife (ONCFS). The figure is important: it "Corresponds to a first threshold of demographic viability" for this protected animal at European level, and the objective of the government "wolf plan" set for 2023.
A common gray wolf in captivity in Belgium, 2011. Photo Caves of Han, CC BY SA
72 packs were found in 85 areas of permanent presence, compared with 57 packs in 74 areas last year. The improvement is indisputable, but it is not enough either: the scientific expertise commissioned by the Ministry of the Environment and made early 2017 (here in PDF) reminds that 500 wolves correspond "To an increase in consanguinity of 1% per generation, which is enough to severely increase the risk of extinction in 20-25 generations". To avoid this, it would be necessary that these 500 wolves are not the total population figure, but that of the "effective size", that is to say the number of animals "Potentially breeding at a given moment". The ratio depends on the age of the wolves, their sex, their fragmentation in space, variations in their reproductive success, seasonal fluctuations in numbers, etc. In fact, it is estimated (according to three studies cited in the report) that effective size represents 0.1 to 0.2% of the total population. It would therefore require 2,500 to 5,000 French wolves "To enable the population to adapt to future changes and thus ensure its long-term viability". Underneath, they will not be able to survive without our help.
Vanilla does not come from America
Where does vanilla come from? His history "Is associated with that of chocolate"says Wikipedia based on the authoritative studies to date: the spice comes from the Mayas and Aztecs, who simmered vanilla chocolate mugs for their nobles and warriors, and were imported to the rest of the world by the Spaniards in the XVIe century. Except that vanilla has just been found in funerary jars in Israel, far from the Americas.
"Tomb 50" jars containing traces of vanilla. Photo Melissa Cradic. Megiddo
"We did not expect such a discovery in the Levant 3,600 years ago!" testified to Science and Future the director of the Megiddo archaeological site, Israel Finkelstein, of Tel Aviv University. The jars come from a burial discovered in 2016. The analyzes revealed traces of olive oil, vanillin and 4-hydroxybenzaldehyde, two chemical components present in vanilla. The Canaanites did not wait for the return of the Spaniards to extract the pods of orchids …
The book of the week: "My thesis in 2 boards"
And if we asked all these obscure students to explain to us clearly the object of their research? The idea was born in 2008 at the University of Queensland, Australia, and she quickly toured the world. In all the faculties, the rules of the "Three Minute Thesis" contest are about the same: the volunteer doctoral students have three minutes to decipher to an audience the impendable title of their thesis, to great reinforcement of funny metaphors and one – only one! – slide to project. The performances are filmed and broadcast on YouTube, where the brightest have their small success.
The head of the scientific and technical team at the University of Lorraine, Nicolas Beck, has been involved in the project since it was imported to France in 2014. "Chick, we make a comic with theses!" he said to himself one day while talking with Peb & Fox, writer and cartoonist Nancy Comic. For three years, the duo has been working on adapting some presentations of Lorraine students in boxes and bubbles, and 33 of them have been released this year in a hardcover compilation at EDP Sciences.
Excerpts from the comic book "My Thesis in 2 Plates"
Instead of the three minutes, each doctoral student has two boards, a double page. The young researcher is staged in the process of explaining his work, and if the popularization exercise is uneven, as in the competition, humor is always present and the diversity of subjects (from climate to climate change). computing going through maths and forests) refreshing.
Peb and Fox, My thesis in 2 boards, EDP Sciences. 80 pages, 17 euros.
The photo of the week
"IT'S PIKACHU !!!!!", exclaims a surfer on Facebook, in front of the photo published by the veterinary clinic of Boronia, in suburbs of Melbourne. It is true that there is an air … The clinic explains that this opossum of Australia, whose congeners are usually brown-gray, has too little melanin because of a rare genetic mutation. "This bright color makes it special to us, but it also attracts predators!" Fortunately for him, the animal will go live in a sanctuary of wildlife after his care.
Photo Boronia Veterinary Clinic And Animal Hospital
At the end of the year, the National Center for Space Studies (Cnes) offers us five posters to download in high definition, and to print to line our walls. Ariane under the spotlights, take off for Mercure, Insight on Mars … The images tell of recent missions in which France took part, and the style is inspired by NASA space posters, themselves in tribute to posters produced by the US government between 1936 and 1943 to promote national parks.
A text by researcher Etienne Klein: To go further, the particle accelerator lifts the foot. The huge CERN machine will shut down for two years – a period called "long shutdown" – for maintenance and improvement work. It will thus be able to get closer to the conditions of the primordial universe, to collide with very high energy protons and to understand reality more finely.
Back in space for the Soyuz rocket. Less than two months after the October 11 accident, which forced two astronauts to land on Earth urgently, the Russian launcher sent a new crew to the space station on Monday.
Osiris-Rex arrives on an asteroid to make the dust. After two years of travel and two million kilometers traveled, the American spacecraft has arrived near Benou, a potentially dangerous asteroid rich in clues about planet formation. It will collect a sample of rocks in 2020.
SpaceX breaks records for recycling and carpooling. The private space operator on Monday launched a rocket already used twice this year, and has still recovered successfully. It has put into orbit a fleet of 64 mini satellites, unpublished in the United States.