BIOMIMETISME - Innovations inspirées par la Nature - Des éoliennes imaginées à partir des nageoires des baleines

Leur taille n'empêche pas les baleines à bosse d'être agiles et gracieuses. Leurs nageoires pectorales, qui peuvent atteindre près d'un tiers de leur taille, leur permettent de réaliser d'impressionnants sauts au-dessus de la surface. Outre leur taille, les nageoires des baleines possèdent une autre caractéristique qui est intéressante en biomimétique : des protubérances, ou bosses, sur toute sa longueur.

Cette particularité anatomique a été utilisée pour concevoir des pales d'éoliennes afin de limiter le risque du décrochage, ce moment où l'angle de la pale n'est plus optimal et où la portance diminue drastiquement et donc ses performances aérodynamiques. Grâce à l'ajout de protubérances, les pales inspirées des baleines ont une meilleure résistance au décrochage, supérieure de 40 % par rapport aux pales classiques. La société canadienne WhalePower a conçu des éoliennes selon ce principe.

© Whit Welles, Wikimedia Commons, CC by-sa 3.0

FuturaSciences

O FUTURO NO PRESENTE - O carro voador chegou (2)

O carro voador mistura elementos importantes de dois veículos bastante úteis: o automóvel e o helicóptero. Este veículo singular realiza uma transformação incrível, passando de veículo terrestre para veículo de voo. Bastam cerca de 5 minutos para o veículo possibilitar essa grande vantagem, voar.

Tendo em conta essa prerrogativa, a transformação é bastante rápida. Ora, tendo em conta as constantes evoluções na tecnologia, futuramente esse tempo ainda será encurtado nos próximos anos.

NCultura

ASTRONOMY - Quadrantids of the North

 2024 January 11

Quadrantids of the North
Image Credit & Copyright: 염범석 Yeom Beom-seok

Explanation: Named for a forgotten constellation, the Quadrantid Meteor Shower puts on an annual show for planet Earth's northern hemisphere skygazers. The shower's radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That location is not far from the Big Dipper asterism, known to some as the Plough, at the boundaries of the modern constellations Bootes and Draco. In fact the Big Dipper "handle" stars are near the upper right corner in this frame, with the meteor shower radiant just below. North star Polaris is toward the top left. Pointing back toward the radiant, Quadrantid meteors streak through the night in this skyscape from Jangsu, South Korea. The composite image was recorded in the hours around the shower's peak on January 4, 2024. A likely source of the dust stream that produces Quadrantid meteors was identified in 2003 as an asteroid.

ASTRONOMY - The Light, the Dark, and the Dusty

 2024 January 10

The Light, the Dark, and the Dusty
Image Credit & Copyright: Gábor Galambos

Explanation: This colorful skyscape spans about three full moons across nebula rich starfields along the plane of our Milky Way Galaxy toward the royal northern constellation Cepheus. Near the edge of the region's massive molecular cloud some 2,400 light-years away, bright reddish emission region Sharpless (Sh)2-155 is at the center of the frame, also known as the Cave Nebula. About 10 light-years across the cosmic cave's bright walls of gas are ionized by ultraviolet light from the hot young stars around it. Dusty bluish reflection nebulae, like vdB 155 at the left, and dense obscuring clouds of dust also abound on the interstellar canvas. Astronomical explorations have revealed other dramatic signs of star formation, including the bright reddish fleck of Herbig-Haro (HH) 168. At the upper left in the frame, the Herbig-Haro object emission is generated by energetic jets from a newborn star.

O FUTURO NO PRESENTE - O carro voador chegou (1)

Antigamente, era impensável as pessoas andarem com um objeto na mão que serve para tudo, mas o telemóvel tornou-se indispensável. É um escritório, uma máquina fotográfica, uma agenda…

Este ano poderá representar o início de uma revolução na área dos veículos. Ter um carro a voar parece coisa de ficção científica, mas é para lá que se caminha.

A imagem que se cria do futuro começa com os sonhos de hoje. O carro voador da Holanda chegou a ser um sonho longínquo, mas o seu desenvolvimento foi algo bem real. Mais recentemente, este veículo singular já se encontrava a encantar nas presenças que realizava em showrooms.

Contudo, será já em 2024 que ele começará a ser vendido. O carro voador começou a ser fabricado por uma startup da Holanda. Este veículo gerou logo interesse, após deixar muitas pessoas boquiabertas. Será já este ano que o carro voador começará a ser entregue aos clientes. Portanto, no futuro, pode não haver filas de espera; pode não haver perda de horas de trânsito infernal.

NCultura

LE JARDIN MERVEILLEUX DES EPICES - Le macis, cousin de la noix de muscade

Le macis est une épice peu connue. Il s'agit en réalité tout simplement de l'enveloppe qui entoure la noix de muscade. Sa saveur est pourtant plus généreuse et raffinée. Avec une petite note d'amertume tout de même. Pour le plaisir des yeux, il prend une belle couleur rouge vif lorsqu'il est frais. Plus orangée et même ambrée, lorsqu'il est séché.

Sachez que le macis fait partie des ingrédients de l'hypocras, la célèbre boisson médiévale. Et on lui prête quelques vertus digestives notamment. Il aiderait ainsi à lutter contre les nausées et les diarrhées. Mais à forte dose, il présente des effets hallucinogènes, voire toxiques.

© emuck/vaitekune, Fotolia ; charlesricardo, Pixabay, CC0 Creative Commons

FuturaSciences

ASTRONOMY - Thor's Helmet

 2024 January 9

Thor's Helmet
Image Credit & Copyright: Ritesh Biswas

Explanation: Thor not only has his own day (Thursday), but a helmet in the heavens. Popularly called Thor's Helmet, NGC 2359 is a hat-shaped cosmic cloud with wing-like appendages. Heroically sized even for a Norse god, Thor's Helmet is about 30 light-years across. In fact, the cosmic head-covering is more like an interstellar bubble, blown with a fast wind from the bright, massive star near the bubble's center. Known as a Wolf-Rayet star, the central star is an extremely hot giant thought to be in a brief, pre-supernova stage of evolution. NGC 2359 is located about 15,000 light-years away toward the constellation of the Great Overdog. This remarkably sharp image is a mixed cocktail of data from narrowband filters, capturing not only natural looking stars but details of the nebula's filamentary structures. The star in the center of Thor's Helmet is expected to explode in a spectacular supernova sometime within the next few thousand years.

ASTRONOMY - The Phases of Venus

 2024 January 8

The Phases of Venus
Image Credit & License: Stéphane Gonzales

Explanation: Venus goes through phases. Just like our Moon, Venus can appear as a full circular disk, a thin crescent, or anything in between. Venus, frequently the brightest object in the post-sunset or pre-sunrise sky, appears so small, however, that it usually requires binoculars or a small telescope to clearly see its current phase. The featured time-lapse sequence was taken over the course of six months in 2015 from Surgères, Charente-Maritime, France, and shows not only how Venus changes phase, but changes angular size as well. When Venus is on the far side of the Sun from the Earth, it appears angularly smallest and nearest to full phase, while when Venus and Earth are on the same side of the Sun, Venus appears larger, but as a crescent. This month Venus rises before dawn in waxing gibbous phases.

LE JARDIN MERVEILLEUX DES EPICES - La badiane, une épice étoilée

Le goût de la badiane est incontestablement anisé. C'est d'ailleurs pour cela -- et pour sa forme particulière -- que l'on appelle aussi la badiane, anis étoilé. Mais attention, à ne pas confondre ce fruit du badianier de Chine avec la badiane japonaise. Cette dernière en effet est une plante toxique.

On attribue à la badiane toute une série de propriétés médicinales. Elle est ainsi reconnue pour ses propriétés antivirales. Consommée en infusion ou ajoutée aux plats ou aux desserts, la badiane aiderait également à atténuer les troubles gastro-intestinaux. Elle agirait aussi sur la fatigue physique et l'anxiété. 

© Daria-Yakovleva, Pixabay, CC0 Creative Commons ; Daderot, Wikimedia Commons, CC0 Creative Commons

FuturaSciences

ASTRONOMY - The Cat's Eye Nebula in Optical and X-ray

 2024 January 7

The Cat's Eye Nebula in Optical and X-ray
Image Credit: NASA, ESA, Hubble Legacy Archive; Chandra X-ray Obs.;
Processing & Copyright: Rudy Pohl

Explanation: To some it looks like a cat's eye. To others, perhaps like a giant cosmic conch shell. It is actually one of the brightest and most highly detailed planetary nebula known, composed of gas expelled in the brief yet glorious phase near the end of life of a Sun-like star. This nebula's dying central star may have produced the outer circular concentric shells by shrugging off outer layers in a series of regular convulsions. The formation of the beautiful, complex-yet-symmetric inner structures, however, is not well understood. The featured image is a composite of a digitally sharpened Hubble Space Telescope image with X-ray light captured by the orbiting Chandra Observatory. The exquisite floating space statue spans over half a light-year across. Of course, gazing into this Cat's Eye, humanity may well be seeing the fate of our sun, destined to enter its own planetary nebula phase of evolution ... in about 5 billion years.