En bref, non, pas pour un usage en chatbot, car si le M5 va 25% plus vite que le M4, l'accélération énorme (jusqu'à 4 fois plus rapide) promise n'est que pour l'ingestion des Tokens du Prompt (l'entrée donc), pas pour le traitement subséquent.
Avec mon prompt maintenant célèbre "Que faire un week-end de vacances à Limoges?" il n'y aura aucune accélération visible, hors les meilleures perfs du M5 face au M4, grâce à sa meilleure bande-passante mémoire. Mais pas nécessairement un meilleur week-end !
Donc en général, non, MLX sous macOS 26.2 n'accélèrera pas grand chose...
The V2 is the first case from the brand that really feels like APNX is coming into its own in terms of design and functionality. Equipped with three glass panes and sporting four 140 mm fans and a controller, it already checks off most boxes. But the unique interior layout is the star of the show. All this at a price point that seems too good to pass up.
Astronomers have long puzzled over the cause of a mysterious “glow” of very high energy gamma radiation emanating from the centre of our galaxy. One possibility is that dark matter – the unknown substance thought to make up more than 25% of the universe’s mass – might be involved. Now, a team led by researchers at Germany’s Leibniz Institute for Astrophysics Potsdam (AIP) says that a flattened rather than spherical distribution of dark matter could account for the glow’s properties, bringing us a step closer to solving the mystery.
Dark matter is believed to be responsible for holding galaxies together. However, since it does not interact with light or other electromagnetic radiation, it can only be detected through its gravitational effects. Hence, while astrophysical and cosmological evidence has confirmed its presence, its true nature remains one of the greatest mysteries in modern physics.
“It’s extremely consequential and we’re desperately thinking all the time of ideas as to how we could detect it,” says Joseph Silk, an astronomer at Johns Hopkins University in the US and the Institut d’Astrophysique de Paris and Sorbonne University in France who co-led this research together with the AIP’s Moorits Mihkel Muru. “Gamma rays, and specifically the excess light we’re observing at the centre of our galaxy, could be our first clue.”
Models might be too simple
The problem, Muru explains, is that the way scientists have usually modelled dark matter to account for the excess gamma-ray radiation in astronomical observations was highly simplified. “This, of course, made the calculations easier, but simplifications always fuzzy the details,” he says. “We showed that in this case, the details are important: we can’t model dark matter as a perfectly symmetrical cloud and instead have to take into account the asymmetry of the cloud.”
Muru adds that the team’s findings, which are detailed in Phys. Rev. Lett., provide a boost to the “dark matter annihilation” explanation of the excess radiation. According to the standard model of cosmology, all galaxies – including our own Milky Way – are nested inside huge haloes of dark matter. The density of this dark matter is highest at the centre, and while it primarily interacts through gravity, some models suggest that it could be made of massive, neutral elementary particles that are their own antimatter counterparts. In these dense regions, therefore, such dark matter species could be mutually annihilating, producing substantial amounts of radiation.
Pierre Salati, an emeritus professor at the Université Savoie Mont Blanc, France, who was not involved in this work, says that in these models, annihilation plays a crucial role in generating a dark matter component with an abundance that agrees with cosmological observations. “Big Bang nucleosynthesis sets stringent bounds on these models as a result of the overall concordance between the predicted elemental abundances and measurements, although most models do survive,” Salati says. “One of the most exciting aspects of such explanations is that dark matter species might be detected through the rare antimatter particles – antiprotons, positrons and anti-deuterons – that they produce as they currently annihilate inside galactic halos.”
Silvia Manconi of the Laboratoire de Physique Théorique et Hautes Energies (LPTHE), France, who was also not involved in the study, describes it as “interesting and stimulating”. However, she cautions that – as is often the case in science – reality is probably more complex than even advanced simulations can capture. “This is not the first time that galaxy simulations have been used to study the implications of the excess and found non-spherical shapes,” she says, though she adds that the simulations in the new work offer “significant improvements” in terms of their spatial resolution.
Manconi also notes that the study does not demonstrate how the proposed distribution of dark matter would appear in data from the Fermi Gamma-ray Space Telescope’s Large Area Telescope (LAT), or how it would differ quantitatively from observations of a distribution of old stars. Forthcoming observations with radio telescopes such as MeerKat and FAST, she adds, may soon identify pulsars in this region of the galaxy, shedding further light on other possible contributions to the excess of gamma rays.
New telescopes could help settle the question
Muru acknowledges that better modelling and observations are still needed to rule out other possible hypotheses. “Studying dark matter is very difficult, because it doesn’t emit or block light, and despite decades of searching, no experiment has yet detected dark matter particles directly,” he tells Physics World. “A confirmation that this observed excess radiation is caused by dark matter annihilation through gamma rays would be a big leap forward.”
New gamma-ray telescopes with higher resolution, such as the Cherenkov Telescope Array, could help settle this question, he says. If these telescopes, which are currently under construction, fail to find star-like sources for the glow and only detect diffuse radiation, that would strengthen the alternative dark matter annihilation explanation.
Muru adds that a “smoking gun” for dark matter would be a signal that matches current theoretical predictions precisely. In the meantime, he and his colleagues plan to work on predicting where dark matter should be found in several of the dwarf galaxies that circle the Milky Way.
“It’s possible we will see the new data and confirm one theory over the other,” Silk says. “Or maybe we’ll find nothing, in which case it’ll be an even greater mystery to resolve.”
Les mises à jour logicielles des consoles de jeu et lecteurs multimédia NVIDIA SHIELD TV se font désormais rares mais ont le mérite de se poursuivre. Le dernier firmware SHIELD Experience 9.2.1 est en effet sorti au printemps dernier pour offrir le streaming de jeux en 1080p à 120 FPS depuis le serv...
Razer proposait début septembre 2025 plusieurs mises à jour logicielles pour certains casques audio des gammes Barracuda, BlackShark et Kraken afin de leur ajouter la compatibilité avec la console de jeu Nintendo Switch 2.
Quelques semaines plus tard, ce fut au tour du casque BlackShark V2 Pro (m...
Si, comme nous, vous avez particulièrement adoré l’époque de l’ascension des Survival-Horror, nous vous conseillons plus que chaudement de lire ce test de Tormented Souls 2. Ode à l’ère de la 3D précalculée et des énigmes, le nouvel opus de Dual Effect. Tout petit studio chilien fondé en 2019, il signe avec cette suite une belle expérience néo-rétro que nous invitons à découvrir plus en détails dans les lignes suivantes.
Test de Tormented Souls 2 | Ce qu’il faut savoir
Jeu d’horreur en vue à la 3ème personne. Vous incarnez Caroline, qui accompagne sa sœur malade dans une bourgade reculée du sud du Chili. Vous allez rapidement vous retrouver seul dans Villa Hess, ville quasi totalement désertée de ses âmes…
Disponible dès maintenant sur PC, PS5 et Xbox Series X|S
Prix de lancement : 30€
Durée de vie : Entre 25 et 30 heures en mode normal pour un premier run
Testé sur PC, via une clé Steam offerte par l’éditeur
Configuration du test : i9-9900KF, 32GO RAM, SSD, RTX 4070
Les gros points forts de Tormented Souls 2
Un Survival-Horror à l’ancienne comme on les adorait à l’époque de Resident Evil, Silent Hill, Dino Crisis, Galerians et compagnie !
Graphiquement, c’est vraiment très souvent magnifique
Les angles de vues et de caméra sont toujours bien choisis
Des énigmes faciles, moyennes, difficiles qui sont toujours bien dosées, et surtout très bien documentées. En cherchant bien, on s’en sort toujours
Un équilibre parfait entre exploration, énigmes, combats et aventure
L’histoire est vraiment passionnante. Racontée aussi bien en scènes cinématiques qu’en notes à trouver un peu partout. C’est très complet !
Une palanquée d’armes à trouver qui offre un inventaire vraiment complet et dévastateur
Les combats de boss sont très bien faits, avec des points faibles à trouver pour chacun
La difficulté globale est bien dosée en mode normal. Vous pouvez également avoir droit à des sauvegardes automatiques en mode facile
Plusieurs fins. Pour avoir la meilleure, il faut vraiment se creuser les méninges et avoir le sens de l’observation !
Une durée de vie exceptionnelle pour un jeu du genre ! Et sans aucune lassitude
Les environnements sont très variés : couvent, bunker, labo
Des inspirations des cadors du genre des années 90 / début 2000 dans tous les sens
Pas énormément d’aller-retours, c’est tant mieux
Des ennemis qui vont flipper ! Moi qui ne sursaute quasi jamais, Tormented Souls 2 a réussi à m’avoir deux ou trois fois !
Doublage en anglais de qualité. Sous-titre français faciles à lire
Bande son très agréable, qui accompagne bien les phases de jeu
On ne manque jamais vraiment de munitions en mode « normal », même s’il ne faut toutefois pas trop en gaspiller
Les points faibles de Tormented Souls 2
Des vilains bugs bloquants ! A deux reprises, j’ai été obligé de lancer une version plus ancienne du jeu sur Steam. Si vous êtes bloqués à la tombe du cimetière et devant l’œil de l’église, pensez-y !
Les personnages sont vraiment beaucoup moins beaux que les environnements somptueux
Le premier tiers de l’aventure est bien plus compliqué que la suite en termes de munitions. Un petit équilibrage serait le bien vu !
Quelques problèmes de déplacements du personnage lorsque l’on a besoin d’esquiver rapidement un ennemi et que l’angle de caméra change (le personnage semble ivre)
Pas de résolution supérieure au 1440P
Pas de prise en charge des écrans 21:9 et 32:9
Vous adorerez le jeu, si :
Vous adorez les vieux Resident Evil, Silent Hill et compagnie
Vous aimez les énigmes logiques, mais pas toujours simples
Vous avez envie de revivre de vieilles sensations, modernisées !
Test de Tormented Souls 2 | Verdict : 18/20
Que l’on soit clair : si Tormented Souls 2 était sorti en 1998, il aurait certainement reçu l’éloge de toutes les critiques, étant encore meilleur que les cadors de l’époque. Nous sommes aujourd’hui en 2025, et le moins que l’on puisse dire est que le titre de Dual Effect fonctionne parfaitement bien. Pour les « vieux de la vieille ». Pour les néophytes, ils risqueront de trouver un jeu rigide, au gameplay « bizarre », mais avec un rythme moderne.
N’ayant fait que partiellement le premier opus, je ne peux que vous conseiller d’investir 30 petits euros dans cette suite qui le surpasse en tous points. Une belle leçon de Survival-Horror à l’ancienne que j’ai vraiment adoré parcourir du début à la fin !
It is book week here at Physics World and over the course of three days we are presenting conversations with the authors of three fascinating and fun books about physics. Today, my guest is the physicist Daniel Whiteson, who along with the artist Andy Warner has created the delightful book Do Aliens Speak Physics?.
Is physics universal, or is it shaped by human perspective? This will be a very important question if and when we are visited by an advanced alien civilization. Would we recognize our visitors’ alien science – or indeed, could a technologically-advanced civilization have no science at all? And would we even be able to communicate about science with our alien guests?
Whiteson, who is a particle physicist at the University of California Irvine, tackles these profound questions and much more in this episode of the Physics World Weekly podcast.
This episode is supported by the APS Global Physics Summit, which takes place on 15–20 March, 2026, in Denver, Colorado, and online.
Are you a science writer attending the 2025 World Conference of Science Journalists (WCSJ) in Pretoria, South Africa? To mark the International Year of Quantum Science and Technology, Physics World (published by the Institute of Physics) and Physics Magazine (published by the American Physical Society) are teaming up to host a special Quantum Pitch Competition for WCSJ attendees.
The two publications invite journalists to submit story ideas on any aspect of quantum science and technology. At least two selected pitches will receive paid assignments and be published in one of the magazines.
Interviews with physicists and career profiles – either in academia or industry – are especially encouraged, but the editors will also consider news stories, podcasts, visual media and other creative storytelling formats that illuminate the quantum world for diverse audiences.
Participants should submit a brief pitch (150–300 words recommended), along with a short journalist bio and a few representative clips, if available. Editors from Physics World and Physics Magazine will review all submissions and announce the winning pitches after the conference. Pitches should be submitted to physics@aps.org by 8 December 2025, with the subject line “2025WCSJ Quantum Pitch”.
Whether you’re drawn to quantum materials, computing, sensing or the people shaping the field, this is an opportunity to feature fresh voices and ideas in two leading physics publications.
A 3D-printed structure called a kagome tube could form the backbone of a new system for muffling damaging vibrations. The structure is part of a class of materials known as topological mechanical metamaterials, and unlike previous materials in this group, it is simple enough to be deployed in real-world situations. According to lead developer James McInerney of the Wright-Patterson Air Force Base in Ohio, US, it could be used as shock protection for sensitive systems found in civil and aerospace engineering applications.
McInerney and colleagues’ tube-like design is made from a lattice of beams arranged in such a way that low-energy vibrational modes called floppy modes become localized to one side. “This provides good properties for isolating vibrations because energy input into the system on the floppy side does not propagate to the other side,” McInerney says.
The key to this desirable behaviour, he explains, is the arrangement of the beams that form the lattice structure. Using a pattern first proposed by the 19th century physicist James Clerk Maxwell, the beams are organized into repeating sub-units to form stable, two-dimensional structures known as topological Maxwell lattices.
Self-supporting design
Previous versions of these lattices could not support their own weight. Instead, they were attached to rigid external mounts, making it impractical to integrate them into devices. The new design, in contrast, is made by folding a flat Maxwell lattice into a cylindrical tube that is self-supporting. The tube features a connected inner and outer layer – a kagome bilayer – and its radius can be precisely engineered to give it the topological behaviour desired.
The researchers, who detail their work in Physical Review Applied, first tested their structure numerically by attaching a virtual version to a mechanically sensitive sample and a source of low-energy vibrations. As expected, the tube diverted the vibrations away from the sample and towards the other end of the tube.
Next, they developed a simple spring-and-mass model to understand the tube’s geometry by considering it as a simple monolayer. This modelling indicated that the polarization of the tube should be similar to the polarization of the monolayer. They then added rigid connectors to the tube’s ends and used a finite-element method to calculate the frequency-dependent patterns of vibrations propagating across the structure. They also determined the effective stiffness of the lattice as they applied loads parallel and perpendicular to it.
The researchers are targeting vibration-isolation applications that would benefit from a passive support structure, especially in cases where the performance of alternative passive mechanisms, such as viscoelastomers, is temperature-limited. “Our tubes do not necessarily need to replace other vibration isolation mechanisms,” McInerney explains. “Rather, they can enhance the capabilities of these by having the load-bearing structure assist with isolation.”
The team’s first and most important task, McInerney adds, will be to explore the implications of physically mounting the kagome tube on its vibration isolation structures. “The numerical study in our paper uses idealized mounting conditions so that the input and output are perfectly in phase with the tube vibrations,” he says. “Accounting for the potential impedance mismatch between the mounts and the tube will enable us to experimentally validate our work and provide realistic design scenarios.”
Black Friday 2025 : Valerion casse les prix sur ses projecteurs laser haut de gamme
À l’occasion du Black Friday, Valerion dégaine une salve de promotions particulièrement agressives, valables du 20 novembre au 1er décembre. La marque lifestyle spécialisée dans les projecteurs laser haut de gamme veut clairement rendre l’expérience home cinéma premium plus accessible que jamais.
La première salve de remises concerne la prestigieuse gamme VisionMaster, équipée d’un laser RVB triple, de 2 500 à 3 000 lumens ISO et d’un contraste pouvant grimper jusqu’à 15 000:1. Pensés pour transformer un salon en véritable salle obscure, ces projecteurs affichent un ensemble de technologies habituellement réservées au très haut de gamme : zoom optique, lens shift vertical, compatibilité Dolby Vision, HDR10+ ou encore IMAX Enhanced. Le tout dans un châssis au design volontairement épuré.
Pour les utilisateurs à la recherche d’un projecteur plus polyvalent et compact, Valerion applique également de belles remises sur sa gamme StreamMaster, elle aussi équipée d’un laser RVB triple et d’une définition 4K UHD. Avec ses 1 650 à 2 000 lumens ISO, son contraste de 10 000:1 et une couverture colorimétrique REC.2020 à 110 %, la série mise sur une image vibrante et dynamique. Les joueurs y trouveront aussi leur compte grâce à une latence de 4 ms en 1080p / 240 Hz.
Avec cette opération Black Friday, Valerion confirme son ambition : rendre le home cinéma laser premium plus abordable sans sacrifier l’innovation. La marque, sous-division haut de gamme d’AWOL Vision, s’est spécialisée dans les projecteurs laser aux optiques de précision et aux performances spectaculaires, avec notamment la VisionMaster, désormais référence sur le marché haute focale.
Une chose est sûre : cette année, le Black Friday s’annonce comme le moment idéal pour équiper son salon d’une vraie expérience cinéma… sans exploser son budget.
À l'occasion du Black Friday, notre partenaire Surfshark propose des promotions conséquentes sur ses produits dès aujourd’hui et pendant les prochaines semaines.
Surfshark est un VPN (réseau privé virtuel) qui vous permet de naviguer en toute sécurité et anonymat sur Internet. Grâce à un chiffrement avancé et une interface simple à utiliser, même les débutants peuvent protéger facilement leurs données personnelles et leur vie privée en ligne.
Vous pouvez protéger tous vos appareils : un seul abonnement peut être activé sur un nombre illimité d’appareils Mac, iPhone, iPad, Apple TV et plus encore sans aucune limitation de bande passante. Aucun autre service ne facilite autant la protection complète d’un foyer.
N’oublions pas ses outils de confidentialité intégrés, comme :
CleanWeb : bloque pubs et trackers
MultiHop (double VPN)
Kill Switch
Protection complète possible avec Surfshark One+ (antivirus, protection d’identité et surveillance de fuite de données)
Surfshark est donc maintenant en offre promotionnelle, vous permettant d'économiser 88 % sur un forfait de 2 ans. Un seul abonnement pouvant être utilisé sur un nombre illimité d'appareils sans contrôle de débit - Mac, iPhone, et Apple TV inclus.
Voici en détails l’offre VPN Black Friday 2025 Surfshark :
Surfshark VPN : abonnement de 2 ans pour 1,99€/mois + 3 mois supplémentaires gratuits
Surfshark One : abonnement de 2 ans pour 2,19€/mois + 3 mois gratuits (inclut VPN, antivirus et fonctionnalités avancées de protection)
Surfshark One+ : abonnement de 2 ans pour 4,19€/mois + 3 mois gratuits
C’est l’un des tarifs les plus bas jamais proposés pour un VPN dit "premium".
Physics Around the Clock: Adventures in the Science of Everyday Living By Michael Banks
Why do Cheerios tend to stick together while floating in a bowl of milk? Why does a runner’s ponytail swing side to side? These might not be the most pressing questions in physics, but getting to the answers is both fun and provides insights into important scientific concepts. These are just two examples of everyday physics that Physics World news editor Michael Banks explores in his book Physics Around the Clock, which begins with the physics (and chemistry) of your morning coffee and ends with a formula for predicting the winner of those cookery competitions that are mainstays of evening television. Hamish Johnston
Quantum 2.0: the Past, Present and Future of Quantum Physics By Paul Davies
You might wonder why the world needs yet another book about quantum mechanics, but for physicists there’s no better guide than Paul Davies. Based for the last two decades at Arizona State University in the US, in Quantum 2.0 Davies tackles the basics of quantum physics – along with its mysteries, applications and philosophical implications – with great clarity and insight. The book ends with truly strange topics such as quantum Cheshire cats and delayed-choice quantum erasers – see if you prefer his descriptions to those we’ve attempted in Physics World this year. Matin Durrani
Can You Get Music on the Moon? the Amazing Science of Sound and Space By Sheila Kanani, illustrated by Liz Kay
Why do dogs bark but wolves howl? How do stars “sing”? Why does thunder rumble? This delightful, fact-filled children’s book answers these questions and many more, taking readers on an adventure through sound and space. Written by planetary scientist Sheila Kanani and illustrated by Liz Kay, Can you get Music on the Moon? reveals not only how sound is produced but why it can make us feel certain things. Each of the 100 or so pages brims with charming illustrations that illuminate the many ways that sound is all around us. Michael Banks
2025 Puffin Books
A Short History of Nearly Everything 2.0 By Bill Bryson
Alongside books such as Stephen Hawking’s A Brief History of Time and Carl Sagan’s Cosmos, British-American author Bill Bryson’s A Short History of Nearly Everything is one of the bestselling popular-science books of the last 50 years. First published in 2003, the book became a fan favourite of readers across the world and across disciplines as Bryson wove together a clear and humorous narrative of our universe. Now, 22 years later, he has released an updated and revised volume – A Short History of Nearly Everything 2.0 – that covers major updates in science from the past two decades. This includes the discovery of the Higgs boson and the latest on dark-matter research. The new edition is still imbued with all the wit and wisdom of the original, making it the perfect Christmas present for scientists and anyone else curious about the world around us. Tushna Commissariat
In this episode of Physics World Stories, theoretical physicist, cosmologist and author Paul Davies discusses his latest book, Quantum 2.0: the Past, Present and Future of Quantum Physics. A Regents Professor at Arizona State University, Davies reflects on how the first quantum revolution transformed our understanding of nature – and what the next one might bring.
He explores how emerging quantum technologies are beginning to merge with artificial intelligence, raising new ethical and philosophical questions. Could quantum AI help tackle climate change or tackle issues like hunger? And how far should we go in outsourcing planetary management to machines that may well prioritize their own survival?
Davies also turns his gaze to the arts, imagining a future where quantum ideas inspire music, theatre and performance. From jazz improvized by quantum algorithms to plays whose endings depend on quantum outcomes, creativity itself could enter a new superposition.
Hosted by Andrew Glester, this episode blends cutting-edge science and imagination in trademark Paul Davies style.
Photodetectors convert light into electrical signals and are essential in technologies ranging from consumer electronics and communications to healthcare. They also play a vital role in scientific research. Researchers are continually working to improve their sensitivity, response speed, spectral range, and design efficiency.
Since the discovery of graphene’s remarkable electrical properties, there has been growing interest in using graphene and other two-dimensional (2D) materials to advance photodetection technologies. When light interacts with these materials, it excites electrons that must travel to a nearby contact electrode to generate an electrical signal. The ease with which this occurs depends on the work functions of the materials involved, specifically, the difference between them, known as the Schottky barrier height. Selecting an optimal combination of 2D material and electrode can minimize this barrier, enhancing the photodetector’s sensitivity and speed. Unfortunately, traditional electrode materials have fixed work functions which are limiting 2D photodetector technology.
PEDOT:PSS is a widely used electrode material in photodetectors due to its low cost, flexibility, and transparency. In this study, the researchers have developed PEDOT:PSS electrodes with tunable work functions ranging from 5.1 to 3.2 eV, making them compatible with a variety of 2D materials and ideal for optimizing device performance in metal-semiconductor-metal architectures. In addition, their thorough investigation demonstrates that the produced photodetectors performed excellently, with a significant forward current flow (rectification ratio ~10⁵), a strong conversion of light to electrical output (responsivity up to 1.8 A/W), and an exceptionally high Ilight/Idark ratio of 10⁸. Furthermore, the detectors were highly sensitive with low noise, had very fast response times (as fast as 3.2 μs), and thanks to the transparency of PEDOT:PSS, showed extended sensitivity into the near-infrared region.
This study demonstrates a tunable, transparent polymer electrode that enhances the performance and versatility of 2D photodetectors, offering a promising path toward flexible, self-powered, and wearable optoelectronic systems, and paving the way for next-generation intelligent interactive technologies.
Quantum Conference Key Agreement (QCKA) is a cryptographic method that allows multiple parties to establish a shared secret key using quantum technology. This key can then be used for secure communication among the parties.
Unlike traditional methods that rely on classical cryptographic techniques, QCKA leverages the principles of quantum mechanics, particularly multipartite entanglement, to ensure security.
A key aspect of QCKA is creating and distributing entangled quantum states among the parties. These entangled states have unique properties that make it impossible for an eavesdropper to intercept the key without being detected.
Researchers measure the efficiency and performance of the key agreement protocol using a metric known as the key rate.
One problem with state-of-the-art QCKA schemes is that this key rate decreases exponentially with the number of users.
Previous solutions to this problem, based on single-photon interference, have come at the cost of requiring global phase locking. This makes them impractical to put in place experimentally.
However, the authors of this new study have been able to circumvent this requirement, by adopting an asynchronous pairing strategy. Put simply, this means that measurements taken by different parties in different places do not need to happen at exactly at the same time.
Their solution effectively removes the need for global phase locking while still maintaining the favourable scaling of the key rate as in other protocols based on single-photon interference.
The new scheme represents an important step towards realising QCKA at long distances by allowing for much more practical experimental configurations.
Schematic representation of quantum group network via circular asynchronous interference (Courtesy: Hua-Lei Yin)
Découvrez notre sélection de jouets pour ce Noël 2025 !
Aujourd’hui, Vonguru s’est penché pour vous afin de vous donner des idées sur les nouveaux jouets à mettre sous le sapin pour ce Noël 2025 ! Après tout, il y a des parents parmi nos lecteurs, alors il faut bien leur proposer quelques petites idées et nouveautés sympas !
Dans cette nouvelle sélection d’idées cadeaux pour Noël nous vous proposerons 15 nouveautés sorties cette année pour offrir à vos enfants ou à ceux de vos proches.
Découvrez notre sélection !
Kit Sven Disney Frozen
Le kit de soin Sven Disney Frozen, c’est le rêve des petits fans de La Reine des Neiges ! Dès 3 ans, les enfants peuvent prendre soin de leur renne préféré avec plein d’accessoires inspirés de l’univers magique de Frozen. Conçu en plastique sans BPA, ce jeu d’imitation à la fois sûr et éducatif développe l’imagination et promet des moments de jeu féeriques tout droit sortis d’Arendelle.
Le coffret Clementoni Stylos Stitch à personnaliser va faire fondre tous les petits fans de Disney ! Dès 6 ans, les enfants peuvent laisser libre cours à leur créativité en décorant leurs stylos grâce à plus de 25 accessoires fun et colorés. Une activité DIY ludique et relaxante, parfaite pour stimuler l’imagination et créer des stylos uniques à l’image de Stitch — une super idée cadeau pour les petits artistes
Le coffret Bluey – Quad de plage avec figurine de Bandit apporte un vrai air de vacances dans les séances de jeu ! Avec son quad robuste, sa planche de surf et la figurine de Bandit (7,6 cm), les enfants peuvent imaginer des aventures fun au bord de la mer. Un set pour les petits fans du dessin animé, parfait pour stimuler l’imagination et rejouer les scènes adorées de Bluey.
La Meccano – Voiture de course F1 2 en 1 plonge les enfants dans l’univers palpitant de la mécanique, de la construction et de la vitesse. Avec ses pièces métalliques et son système d’assemblage emblématique, ils peuvent construire deux modèles différents, pour deux fois plus de fun et de défis. Un kit parfait pour booster la logique, la patience et la créativité, tout en se glissant dans la peau d’un vrai ingénieur en herbe.
Le Photo Creator Mini Cam Rose, c’est le premier vrai appareil photo des petits créateurs ! Facile à prendre en main et pensé spécialement pour les enfants, il leur permet de capturer leurs propres photos et vidéos comme des grands. Un super moyen de développer leur créativité tout en s’amusant et en immortalisant leurs plus jolis souvenirs
La poupée BABY born Emma, c’est le bébé dont rêvent tous les petits parents en herbe. Avec ses 10 fonctions ultra réalistes — elle boit, pleure, fait pipi et ferme même les yeux — elle offre une expérience de jeu plus vraie que nature, et tout ça sans piles ! Livrée avec plein de petits accessoires trop mignons (biberon, pot, assiette, cuillère, couche, etc.) et sa grenouillère toute douce, elle est parfaite dès 3 ans pour stimuler les jeux d’imitation, la motricité fine et, surtout, la tendresse.
Hitster, c’est LE jeu d’ambiance qui va animer vos vacances de Noël ! Le principe est simple : tu écoutes un extrait musical et tu dois le replacer dans la bonne chronologie. Facile ? Pas vraiment, surtout quand les décennies s’enchaînent ! Avec plus de 100 ans de hits, de la chanson rétro aux tubes d’aujourd’hui, c’est un voyage musical plein de fous rires à faire en famille ou entre amis. Parfait pour les soirées où tu veux prouver que c’est bien toi le vrai mélomane du groupe.
Boule Miniverse – Harry Potter Make It Mini Potions
Le MGA’s Miniverse Make It Mini Potions – Harry Potter, c’est la rencontre parfaite entre magie et DIY ! Ce coffret permet de créer ses propres mini potions en résine, inspirées de l’univers d’Harry Potter, avec un réalisme bluffant. Un vrai plaisir de collectionneur et une activité créative captivante dès 8 ans, pour tous ceux qui rêvent d’avoir leur petit coin de Poudlard à la maison.
Le Ravensburger Play+ – Mes premières brochettes à empiler, c’est un jeu d’éveil coloré et ludique qui ravira les tout-petits dès 18 mois ! Grâce aux pièces faciles à attraper, les enfants s’amusent à empiler, enfiler et créer leurs propres brochettes, tout en développant leur motricité fine et leur coordination. Un jouet malin, 100 % adapté aux petites mains, pour apprendre en s’amusant dès le plus jeune âge.
Le puzzle recto-verso Kididoc Châteaux forts et Chevaliers de Nathan est une aventure médiévale pleine de découvertes ! Avec ses 35 pièces de qualité supérieure et un encastrement parfait, il est idéal pour les enfants dès 4 ans. En plus, il est recto-verso : deux illustrations à assembler pour deux fois plus de plaisir et d’apprentissage tout en développant la concentration et la logique.
Clementoni – Puzzle Carte du Monde Magnétique en Bois
Le puzzle magnétique du Monde de Clementoni transforme la découverte de la planète en un jeu interactif passionnant ! Dès 4 ans, les enfants placent les magnets pour reconnaître animaux, monuments et continents, tout en s’amusant à explorer le globe. Un jeu éducatif et ludique qui éveille la curiosité, enrichit les connaissances et donne envie de voyager.
Le jeu d’apprentissage Dessineo BD de Nathan transforme le dessin en véritable aventure créative ! Compact et pratique avec ses 27 x 27 x 6 cm, il permet aux enfants de créer leurs propres histoires en bande dessinée tout en s’amusant. Une activité ludique et éducative qui stimule la créativité, l’imagination et le sens de la narration dès le plus jeune âge.
Le kit scientifique L’Observatoire des Insectes de Clémentoni transforme chaque sortie en véritable exploration de la nature ! Conçu pour les enfants dès 7 ans, il inclut une loupe, une boîte d’observation et des fiches explicatives pour découvrir insectes et petites bêtes de près. Une activité ludique et éducative qui éveille la curiosité, stimule l’esprit scientifique et fait aimer la biologie dès le plus jeune âge.
Le kit Clementoni Star Wars R2-D2 Robot permet aux enfants dès 8 ans de construire leur propre droïde emblématique ! Avec plus de 50 pièces et une application de programmation, ils peuvent le faire bouger et interagir, alliant jeu et apprentissage. Un jouet éducatif et immersif, parfait pour stimuler la logique, la créativité et les compétences en codage, tout en plongeant dans l’univers Star Wars.
Les PLAYMOBIL Icon Cars offrent aux enfants la chance de plonger dans l’univers passionnant des voitures de collection . Chaque véhicule est détaillé et prêt à l’action, parfait pour des heures de jeu imaginatif seul ou entre amis. Un jouet élégant et ludique qui stimule la créativité, la motricité et la passion pour les voitures dès le plus jeune âge.
Non, on ne parle pas ici de la prochaine saison de la série Stranger Things qui arrive sur Netflix le 27 novembre prochain… mais bien d’une enquête de chez Dossiers Criminels… En effet, le désormais célèbre jeu d’enquêtes (on les a toutes faites!), s’est associé à Netflix pour proposer une nouvelle intrigue dans l’univers de la série avec une histoire inédite…
Quelque chose dérange l’équilibre fragile de la ville de Hawkins… A nous de parcourir la ville, mener l’enquête et élucider le mystère… Mais au début, on ne sait pas vraiment ce qui se passe… qui a disparu? Quand? Où?… Alors, quand on connait la série on se doute bien de ce qui se trame… mais l’intrigue se dévoile au fur et à mesure, enveloppe par enveloppe…
En effet, le jeu s’articule autour d’un site web qui fait office d’ordi des années 80 dans lequel on aura des infos et autre documents à lire ou bien des choses à écouter grâce à un walkman… et c’est particulièrement en progressant sur la carte de Hawkins fournie qu’on pourra avancer, en proposant un lieu sur la carte via le site web, on pourra débloquer la suite…
Bien sûr, comme dans toute bonne enquête Dossiers Criminels, les enveloppes contiennent tout un tas de documents ou même objets… On trouve des coupures de journaux, des photos, des brochures, etc…
Par rapport aux enquêtes qu’on connait dans la collection, il y a moins à lire ici et les documents sont plus faciles à appréhender car davantage visuels. Aussi, on pourra résoudre pas mal d’énigmes à base de signes ou autres visuels à bien analyser sous tous les angles.
L’enquête, d’une difficulté de 2 sur 5 est ainsi très abordable à tous types de joueuses et joueurs. La progression est rythmée et plutôt addictive avec une bonne immersion dans l’univers de Strangers Things par ses visuels et l’ambiance sonore de certains messages. Un effort particulier a été fait en ce qui concerne la réalisation des documents avec beaucoup d’allusions aux personnages de la série.
Il vous faudra environ 1h30 pour terminer cette enquête, idéalement à 3 joueurs ou plus (à partir de 14 ans). L’enquête est accessible et bien ficelée avec une réalisation de haute volée pour une immersion dans l’univers qui ravira les fans (il est même parfois question de jeu de rôles…). Si vous ne connaissez pas les Dossiers Criminels c’est un excellent moyen pour découvrir ces enquêtes à faire à la maison!
Coherent crystalline interfaces Atomic-resolution image of a superconducting germanium:gallium (Ge:Ga) trilayer with alternating Ge:Ga and silicon layers demonstrating precise control of atomic interfaces. (Courtesy: Salva Salmani-Rezaie)
The ability to induce superconductivity in materials that are inherently semiconducting has been a longstanding research goal. Improving the conductivity of semiconductor materials could help develop quantum technologies with a high speed and energy efficiency, including superconducting quantum bits (qubits) and cryogenic CMOS control circuitry. However, this task has proved challenging in traditional semiconductors – such as silicon or germanium – as it is difficult to maintain the optimal superconductive atomic structure.
In a new study, published in Nature Nanotechnology, researchers have used molecular beam epitaxy (MBE) to grow gallium-hyperdoped germanium films that retain their superconductivity. When asked about the motivation for this latest work, Peter Jacobson from the University of Queensland tells Physics World about his collaboration with Javad Shabani from New York University.
“I had been working on superconducting circuits when I met Javad and discovered the new materials their team was making,” he explains. “We are all trying to understand how to control materials and tune interfaces in ways that could improve quantum devices.”
Germanium: from semiconductor to superconductor
Germanium is a group IV element, so its properties bridge those of both metals and insulators. Superconductivity can be induced in germanium by manipulating its atomic structure to introduce more electrons into the atomic lattice. These extra electrons interact with the germanium lattice to create electron pairs that move without resistance, or in other words, they become superconducting.
Hyperdoping germanium (at concentrations well above the solid solubility limit) with gallium induces a superconducting state. However, this material is traditionally unstable due to the presence of structural defects, dopant clustering and poor thickness control. There have also been many questions raised as to whether these materials are intrinsically superconducting, or whether it is actually gallium clusters and unintended phases that are solely responsible for the superconductivity of gallium-doped germanium.
Considering these issues and looking for a potential new approach, Jacobson notes that X-ray absorption measurements at the Australian Synchrotron were “the first real sign” that Shabani’s team had grown something special. “The gallium signal was exceptionally clean, and early modelling showed that the data lined up almost perfectly with a purely substitutional picture,” he explains. “That was a genuine surprise. Once we confirmed and extended those results, it became clear that we could probe the mechanism of superconductivity in these films without the usual complications from disorder or spurious phases.”
Epitaxial growth improves superconductivity control
In a new approach, Jacobson, Shabani and colleagues used MBE to grow the crystals instead of relying on ion implantation techniques, allowing the germanium to by hyperdoped with gallium. Using MBE forces the gallium atoms to replace germanium atoms within the crystal lattice at levels much higher than previously seen. The process also provided better control over parasitic heating during film growth, allowing the researchers to achieve the structural precision required to understand and control the superconductivity of these germanium:gallium (Ge:Ga) materials, which were found to become superconducting at 3.5 K with a carrier concentration of 4.15 × 1021 holes/cm3. The critical gallium dopant threshold to achieve this was 17.9%.
Using synchrotron-based X-ray absorption, the team found that the gallium dopants were substitutionally incorporated into the germanium lattice and induced a tetragonal distortion to the unit cell. Density functional theory calculations showed that this causes a shift in the Fermi level into the valence band and flattens electronic bands. This suggests that the structural order of gallium in the germanium lattice creates a narrow band that facilitates superconductivity in germanium, and that this superconductivity arises intrinsically in the germanium, rather than being governed by defects and gallium clusters.
The researchers tested trilayer heterostructures – Ge:Ga/Si/Ge:Ga and Ge:Ga/Ge/Ge:Ga – as proof-of-principle designs for vertical Josephson junction device architectures. In the future, they hope to develop these into fully fledged Josephson junction devices.
Commenting on the team’s future plans for this research, Jacobson concludes: “I’m very keen to examine this material with low-temperature scanning tunnelling microscopy (STM) to directly measure the superconducting gap, because STM adds atomic-scale insights that complement our other measurements and will help clarify what sets hyperdoped germanium apart”.
It is book week here at Physics World and over the course of three days we are presenting conversations with the authors of three fascinating and fun books about physics. First up is my Physics World colleague Michael Banks, whose book Physics Around the Clock: Adventures in the Science of Everyday Living starts with your morning coffee and ends with a formula for making your evening television viewing more satisfying.
As well as the rich physics of coffee, we chat about strategies for finding the best parking spot and the efficient boarding of aeroplanes. If you have ever wondered why a runner’s ponytail swings from side-to-side when they reach a certain speed – we have the answer for you.
Other daily mysteries that we explore include how a hard steel razor blade can be dulled by cutting relatively soft hairs and why quasiparticles called “jamitons” are helping physicists understand the spontaneous appearance of traffic jams. And a warning for squeamish listeners, we do talk about the amazing virus-spreading capabilities of a flushing toilet.
This episode is supported by the APS Global Physics Summit, which takes place on 15–20 March, 2026, in Denver, Colorado, and online.
Début 2025, un gigantesque incendie a ravagé plus de la moitié de l’île Amsterdam. De retour sur place plusieurs mois après, des scientifiques tentent d’en estimer les conséquences sur ce havre de biodiversité à la croisée de l’océan Indien et de l’Antarctique.
Marstek lance Venus E 3.0, la batterie qui récupère enfin tout votre surplus solaire
Marstek s’attaque à l’un des plus grands gâchis du photovoltaïque résidentiel : le surplus d’énergie perdu chaque jour faute de solution de stockage adaptée. Avec sa nouvelle batterie Venus E 3.0, la marque propose une réponse étonnamment simple : il suffit de la brancher sur une prise 230 V. Pas besoin de changer d’onduleur, ni de toucher à l’installation existante.
Une fois connectée, la Venus E 3.0 absorbe automatiquement l’excédent d’électricité produit la journée pour le restituer le soir. Elle s’appuie sur une compatibilité étendue avec la majorité des compteurs intelligents afin d’éviter toute injection réseau, assurant ainsi une autoconsommation à 100 % – un argument fort pour les foyers souhaitant optimiser leurs économies.
Mais la force du produit réside surtout dans son mode « AI Optimization » : une gestion intelligente qui planifie en temps réel la charge et la décharge en fonction des habitudes du foyer, du prix de l’électricité ou encore des prévisions météo. L’utilisateur n’a rien à faire : la batterie choisit les moments les plus rentables pour stocker ou restituer l’énergie. Les profils plus techniques pourront toutefois passer en mode manuel et définir eux-mêmes les plages et puissances de charge selon les tarifs horaires.
Positionnée à un prix compétitif pour une capacité de 5,12 kWh, la Venus E 3.0 mise également sur la durabilité. Elle s’appuie sur des cellules LFP (Lithium Fer Phosphate) qui supportent plus de 6 000 cycles, soit près de 15 ans d’utilisation. De quoi en faire un investissement fiable, à la fois économique et écologique.
Adaptée à tous les environnements – balcon, garage ou local technique –, la Venus E 3.0 s’inscrit pleinement dans l’ambition de Marstek : rendre le stockage d’énergie plus intelligent, plus sûr et plus accessible. Pour soutenir son expansion en France, la marque s’appuie désormais sur l’agence WEMOOVE, spécialisée dans les nouvelles technologies et le lifestyle.
Fondée en 2009, Marstek est aujourd’hui un acteur international majeur du stockage énergétique, avec une gamme allant des systèmes résidentiels aux batteries portables, en passant par les solutions pour balcons et les piles Li-ion AA/AAA. Présente en Chine, en France, aux États-Unis, au Japon et en Afrique, la marque poursuit un objectif clair : simplifier l’accès à l’énergie propre.
“This is one of the big remaining frontiers in astronomy,” says Phil Bull, a cosmologist at the Jodrell Bank Centre for Astrophysics at the University of Manchester. “It’s quite a pivotal era of cosmic history that, it turns out, we don’t actually understand.”
Bull is referring to the vital but baffling period in the early universe – from 380,000 years to one billion years after the Big Bang – when its structure went from simple to complex. To lift the veil on this epoch, experiments around the world – from Australia to the Arctic – are racing to find a specific but elusive signal from the earliest hydrogen atoms. This signal could confirm or disprove scientists’ theories of how the universe evolved and the physics that governs it.
Hydrogen is the most abundant element in the universe. As neutral hydrogen atoms change states, they can emit or absorb photons. This spectral transition, which can be stimulated by radiation, produces an emission or absorption radio wave signal with a wavelength of 21 cm. To find out what happened during that early universe, astronomers are searching for these 21 cm photons that were emitted by primordial hydrogen atoms.
But despite more teams joining the hunt every year, no-one has yet had a confirmed detection of this radiation. So who will win the race to find this signal and how is the hunt being carried out?
A blank spot
Let’s first return to about 380,000 years after the Big Bang, when the universe had expanded and cooled to below 3000 K. At this stage, neutral atoms, including atomic hydrogen, could form. Thanks to the absence of free electrons, ordinary matter particles could decouple from light, allowing it to travel freely across the universe. This ancient radiation that permeates the sky is known as the cosmic microwave background (CMB).
But after that we don’t know much about what happened for the next few hundred million years. Meanwhile, the oldest known galaxy MoM-z14 – which existed about 280 million years after the Big Bang – was observed in April 2025 by the James Webb Space Telescope. So there is currently a gap of just under 280 million years in our observations of the early universe. “It’s one of the last blank spots,” says Anastasia Fialkov, an astrophysicist at the Institute of Astronomy of the University of Cambridge.
This “blank spot” is a bridge between the early, simple universe and today’s complex structured cosmos. During this early epoch, the universe went from being filled with a thick cloud of neutral hydrogen, to being diversely populated with stars, black holes and everything in between. It covers the end of the cosmic dark ages, the cosmic dawn, and the epoch of reionization – and is arguably one of the most exciting periods in our universe’s evolution.
During the cosmic dark ages, after the CMB flooded the universe, the only “ordinary” matter (made up of protons, neutrons and electrons) was neutral hydrogen (75% by mass) and neutral helium (25%), and there were no stellar structures to provide light. It is thought that gravity then magnified any slight fluctuations in density, causing some of this primordial gas to clump and eventually form the first stars and galaxies – a time called the cosmic dawn. Next came the epoch of reionization, when ultraviolet and X-ray emissions from those first celestial objects heated and ionized the hydrogen atoms, turning the neutral gas into a charged plasma of electrons and protons.
Stellar imprint
The 21 cm signal astronomers are searching for was produced when the spectral transition was excited by collisions in the hydrogen gas during the dark ages and then by the first photons from the first stars during the cosmic dawn. However, the intensity of the 21 cm signal can only be measured against the CMB, which acts as a steady background source of 21 cm photons.
When the hydrogen was colder than the background radiation, there were few collisions, and the atoms would have absorbed slightly more 21 cm photons from the CMB than they emitted themselves. The 21 cm signal would appear as a deficit, or absorption signal, against the CMB. But when the neutral gas was hotter than the CMB, the atoms would emit more photons than they absorbed, causing the 21 cm signal to be seen as a brighter emission against the CMB. These absorption and emission rates depend on the density and temperature of the gas, and the timing and intensity of radiation from the first cosmic sources. Essentially, the 21 cm signal became imprinted with how those early sources transformed the young universe.
One way scientists are trying to observe this imprint is to measure the average – or “global” – signal across the sky, looking at how it shifts from absorption to emission compared to the CMB. Normally, a 21 cm radio wave signal has a frequency of about 1420 MHz. But this ancient signal, according to theory, has been emitted and absorbed at different intensities throughout this cosmic “blank spot”, depending on the universe’s evolutionary processes at the time. The expanding universe has also stretched and distorted the signal as it travelled to Earth. Theories predict that it would now be in the 1 to 200 MHz frequency range – with lower frequencies corresponding to older eras – and would have a wavelength of metres rather than centimetres.
Importantly, the shape of the global 21 cm signal over time could confirm the lambda-cold dark matter (ΛCDM) model, which is the most widely accepted theory of the cosmos; or it could upend it. Many astronomers have dedicated their careers to finding this radiation, but it is challenging for a number of reasons.
Unfortunately, the signal is incredibly faint. Its brightness temperature, which is measured as the change in the CMB’s black body temperature (2.7 K), will only be in the region of 0.1 K.
a A simulation of the sky-averaged (global) signal as a function of time (horizontal) and space (vertical). b A typical model of the global 21 cm line with the main cosmic events highlighted. Each experiment searching for the global 21 cm signal focuses on a particular frequency band. For example, the Radio Experiment for the Analysis of Cosmic Hydrogen (REACH) is looking at the 50–170 MHz range (blue).
There is also no single source of this emission, so, like the CMB, it permeates the universe. “If it was the only signal in the sky, we would have found it by now,” says Eloy de Lera Acedo, head of Cavendish Radio Astronomy and Cosmology at the University of Cambridge. But the universe is full of contamination, with the Milky Way being a major culprit. Scientists are searching for 0.1 K in an environment “that’s a million times brighter”, he explains.
And even before this signal reaches the radio-noisy Earth, it has to travel through the atmosphere, which further distorts and contaminates it. “It’s a very difficult measurement,” says Rigel Cappallo, a research scientist at the MIT Haystack Observatory. “It takes a really, really well calibrated instrument that you understand really well, plus really good modelling.”
The EDGES instrument is a dipole antenna, which resembles a ping-pong table with a gap in the middle (see photo at top of article for the 2024 set-up). It is mounted on a large metal groundsheet, which is about 30 × 30 m. Its ground-breaking observation was made at a remote site in western Australia, far from radio frequency interference.
But in the intervening seven years, no-one else has been able to replicate the EDGES results.
The spectrum dip that EDGES detected was very different from what theorists had expected. “There is a whole family of models that are predicted by the different cosmological scenarios,” explains Ravi Subrahmanyan, a research scientist at Australia’s national science agency CSIRO. “When we take measurements, we compare them with the models, so that we can rule those models in or out.”
In general, the current models predict a very specific envelope of signal possibilities (see figure 1). First, they anticipate an absorption dip in brightness temperature of around 0.1 to 0.2 K, caused by the temperature difference between the cold hydrogen gas (in an expanding universe) and the warmer CMB. Then, a speedy rise and photon emission is predicted as the gas starts to warm when the first stars form, and the signal should spike dramatically when the first X-ray binary stars fire up and heat up the surrounding gas. The signal is then expected to fade as the epoch of reionization begins, because ionized particles cannot undergo the spectral transition. With models, scientists theorize when this happened, how many stars there were, and how the cosmos unfurled.
2 Weird signal
(Courtesy: SARAS Team)
The 21 cm signals predicted by current cosmology models (coloured lines) and the detection by the EDGES experiment (dashed black line).
“It’s just one line, but it packs in so many physical phenomena,” says Fialkov, referring to the shape of the 21 cm signal’s brightness temperature over time. The timing of the dip, its gradient and magnitude all represent different milestones in cosmic history, which affect how it evolved.
The EDGES team, however, reported a dip of more than double the predicted size, at about 78 MHz (see figure 2). While the frequency was consistent with predictions, the very wide and deep dip of the signal took the community by surprise.
“It would be a revolution in physics, because that signal will call for very, very exotic physics to explain it,” says de Lera Acedo. “Of course, the first thing we need to do is to make sure that that is actually the signal.”
A spanner in the works
The EDGES claim has galvanized the cosmology community. “It set a cat among the pigeons,” says Bull. “People realized that, actually, there’s some very exciting science to be done here.” Some groups are trying to replicate the EDGES observation, while others are trying new approaches to detect the signal that the models promise.
The Radio Experiment for the Analysis of Cosmic Hydrogen (REACH) – a collaboration between the University of Cambridge and Stellenbosch University in South Africa – focuses on the 50–170 MHz frequency range. Sitting on the dry and empty plains of South Africa’s Northern Cape, it is targeting the EDGES observation (Nature Astronomy 6 984).
The race to replicate REACH went online in the Karoo region of South Africa in December 2023. (Courtesy: Saurabh Pegwal, REACH collaboration)
In this radio-quiet environment, REACH has set up two antennas: one looks like EDGES’ dipole ping-pong table, while the other is a spiral cone. They sit on top of a giant metallic mesh – the ground plate – in the shape of a many-pointed star, which aims to minimize reflections from the ground.
Hunting for this signal “requires precision cosmology and engineering”, says de Lera Acedo, the principal investigator on REACH. Reflections from the ground or mesh, calibration errors, and signals from the soil, are the kryptonite of cosmic dawn measurements. “You need to reduce your systemic noise, do better analysis, better calibration, better cleaning [to remove other sources from observations],” he says.
Desert, water, snow
Another radio telescope, dubbed the Shaped Antenna measurement of the background Radio Spectrum (SARAS) – which was established in the late 2000s by the Raman Research Institute (RRI) in Bengaluru, India – has undergone a number of transformations to reduce noise and limit other sources of radiation. Over time, it has morphed from a dipole on the ground to a metallic cone floating on a raft. It is looking at 40 to 200 MHz (Exp. Astron.51 193).
After the EDGES claim, SARAS pivoted its attention to verifying the detection, explains Saurabh Singh, a research scientist at the RRI. “Initially, we were not able to get down to the required sensitivity to be able to say anything about their detection,” he explains. “That’s why we started floating our radiometer on water.” Buoying the experiment reduces ground contamination and creates a more predictable surface to include in calculations.
Floating telescope Evolution of the SARAS experiment and sites up to 2020. The third edition of the telescope, SARAS 3, was deployed on lakes to further reduce radio interference. (Courtesy: SARAS Team)
Using data from their floating radiometer, in 2022 Singh and colleagues disfavoured EDGES’ claim (Nature Astronomy 6 607), but for many groups the detection still remains a target for observations.
While SARAS has yet to detect a cosmic-dawn signal of its own, Singh says that non-detection is also an important element of finding the global 21 cm signal. “Non-detection gives us an opportunity to rule out a lot of these models, and that has helped us to reject a lot of properties of these stars and galaxies,” he says.
Raul Monsalve Jara – a cosmologist at the University of California, Berkeley – has been part of the EDGES collaboration since 2012, but decided to also explore other ways to detect the signal. “My view is that we need several experiments doing different things and taking different approaches,” he says.
The Mapper of the IGM Spin Temperature (MIST) experiment, of which Monsalve is co-principal investigator, is a collaboration between Chilean, Canadian, Australian and American researchers. These instruments are looking at 25 to 105 MHz (MNRAS 530 4125). “Our approach was to simplify the instrument, get rid of the metal ground plate, and to take small, portable instruments to remote locations,” he explains. These locations have to fulfil very specific requirements – everything around the instrument, from mountains to the soil, can impact the instrument’s performance. “If the soil itself is irregular, that will be very difficult to characterize and its impact will be difficult to remove [from observations],” Monsalve says.
Physics on the move MIST conducts measurements of the sky-averaged radio spectrum at frequencies below 200 MHz. Its monopole and dipole variants are highly portable and have been deployed in some of the most remote sites on Earth, including the Arctic (top) and the Nevada desert (bottom). (Courtesy: Raul Monsalve)
So far, the MIST instrument, which is also a dipole ping-pong table, has visited a desert in California, another in Nevada, and even the Arctic. Each time, the researchers spend a few weeks at the site collecting data, and it is portable and easy to set up, Monsalve explains. The team is planning more observations in Chile. “If you suspect that your environment could be doing something to your measurements, then you need to be able to move around,” continues Monsalve. “And we are contributing to the field by doing that.”
Aaron Parsons, also from the University of California, Berkeley, decided that the best way to detect this elusive signal would be to try and eliminate the ground entirely – by suspending a rotating antenna over a giant canyon with 100 m empty space in every direction.
His Electromagnetically Isolated Global Signal Estimation Platform (EIGSEP) includes an antenna hanging four storeys above the ground, attached to Kevlar cable strung across a canyon in Utah. It’s observing at 50 to 250 MHz. “It continuously rotates around and twists every which way,” Parsons explains. Hopefully, that will allow them to calibrate the instrument very accurately. Two antennas on the ground cross-correlate observations. EIGSEP began making observations last year.
More experiments are expected to come online in the next year. The Remote HI eNvironment Observer (RHINO), an initiative of the University of Manchester, will have a horn-shaped receiver made of a metal mesh that is usually used to construct skyscrapers. Horn shapes are particularly good for calibration, allowing for very precise measurements. The most famous horn-shaped antenna is Bell Laboratories’ Holmdel Horn Antenna in the US, with which two scientists accidentally discovered the CMB in 1965.
Initially, RHINO will be based at Jodrell Bank Observatory in the UK, but like other experiments, it could travel to other remote locations to hunt for the 21 cm signal.
Similarly, Subrahmanyan – who established the SARAS experiment in India and is now with CSIRO in Australia – is working to design a new radiometer from scratch. The instrument, which will focus on 40–160 MHz, is called Global Imprints from Nascent Atoms to Now (GINAN). He says that it will feature a recently patented self-calibrating antenna. “It gives a much more authentic measurement of the sky signal as measured by the antenna,” he explains.
In the meanwhile, the EDGES collaboration has not been idle. MIT Haystack Observatory’s Cappallo project manages EDGES, which is currently in its third iteration. It is still the size of a desk, but its top now looks like a box, with closed sides and its electronics tucked inside, and an even larger metal ground plate. The team has now made observations from islands in the Canadian archipelago and in Alaska’s Aleutian island chain (see photo at top of article).
“The 2018 EDGES result is not going to be accepted by the community until somebody completely independently verifies it,” Cappallo explains. “But just for our own sanity and also to try to improve on what we can do, we want to see it from as many places as possible and as many conditions as possible.” The EDGES team has replicated its results using the same data analysis pipeline, but no-one else has been able to reproduce the unusual signal.
All the astronomers interviewed welcomed the introduction of new experiments. “I think it’s good to have a rich field of people trying to do this experiment because nobody is going to trust any one measurement,” says Parsons. “We need to build consensus here.”
Taking off
Some astronomers have decided to avoid the struggles of trying to detect the global 21 cm signal from Earth – instead, they have their sights set on the Moon. Earth’s atmosphere is one of the reasons why the 21 cm signal is so difficult to measure. The ionosphere, a charged region of the atmosphere, distorts and contaminates this incredibly faint signal. On the far side of the Moon, any antenna would also be shielded from the cacophony of radio-frequency interference from Earth.
“This is why some experiments are going to the Moon,” says Parsons, adding that he is involved in NASA’s LuSEE-Night experiment. LuSEE-Night, or the Lunar Surface Electromagnetics Experiment, aims to land a low-frequency experiment on the Moon next year.
In July, at the National Astronomical Meeting in Durham, the University of Cambridge’s de Lera Acedo presented a proposal to put a miniature radiometer into lunar orbit. Dubbed “Cosmocube”, it will be a nanosatellite that will orbit the Moon searching for this 21 cm signal.
Taking the hunt to space Provisional illustration of the CosmoCube with its antenna deployed for the 21 cm signal detection, i.e. in operational mode in space. This nanosatellite would travel to the far side of the Moon to get away from the Earth’s ionosphere, which introduces substantial distortions and absorption effects to any radio signal detection. (CC BY 4.0 Artuc and de Lera Acedo 2024 RAS Techniques and Instruments4 rzae061)
“It is just in the making,” says de Lera Acedo, adding that it will not be in operation for at least a decade. “But it is the next step.”
In the meanwhile, groups here on Earth are in a race to detect this elusive signal. The instruments are getting more sensitive, the modelling is improving, and the unknowns are reducing. “If we do the experiments right, we will find the signal,” Monsalve believes. The big question is who, of the many groups with their hat in the ring, is doing the experiment “right”.
Un tout nouveau jeu multijoueur est disponible depuis le début du mois et c’est le phénomène du moment !
Arc Raiders vous propose une expérience intense et immersive dans un futur post-apo dans lequel les robots sont les maîtres de cet univers. A noter, que ce titre n’est pas un free-to-play et il vous faudra débourser la somme de 39,99€ pour profiter de cette expérience. Le jeu enregistre des records de fréquentation sur ses serveurs et si vous êtes à la recherche de jeux à découvrir avec vos amis, Arc Raiders tombe au bon moment.
Un jeu multi jouable en solo !
Arc Raiders est un jeu multijoueur d’extraction shooter qui mélange PvP et PvE. Cette nouvelle franchise propose un univers unique qui vous permet d’incarner un Raiders à la recherche de ressources pour contribuer à la survie de votre abri. Arc Raiders ne propose pas une histoire classique mais ponctue la narration de son lore par des textes à lire et des quêtes à réaliser.
Vos parties peuvent être jouées à plusieurs avec un maximum de 3 personnes par équipe. Cependant si vous souhaitez jouer en solitaire, c’est possible mais les phases de gunfight entre les différentes équipes du jeu sont assez dures à gérer. Il vous faudra vous infiltrer pour récupérer le maximum de ressources sans vous faire tuer ou vous allier avec d’autres joueurs pour rentrer sain et sauf à votre base. Personnellement j’ai essayé de jouer seul et à chaque fois je suis mort, je préfère jouer avec des inconnus pour augmenter mes chances de survie et c’est toujours sympa de discuter avec des personnes du monde entier. C’est ainsi que j’ai rencontré un joueur italien avec qui on a réussi nos premières missions. Le jeu propose un chat de proximité, ce qui favorise l’immersion et permet de discuter avec des joueurs ennemis pour tenter d’apaiser les conflits.
Avant chaque début de mission dans Arc Raiders, vous allez pouvoir choisir la carte sur laquelle vous souhaitez être déployé. Chaque environnement est assez différent et propose des situations plus ou moins urbaines. Au début, vous allez jouer sur une carte qui mélange forêt et désert avec très peu de bâtiments mais plus vous allez progresser dans le jeu plus vous aurez accès à certaines parties de ville. Il vous faudra faire attention car les villes regorgent de cachettes pour les joueurs ennemis et les robots présents sur ces cartes sont plus agressifs. Dans Arc Raiders, la gestion de vos ressources, de votre sac à dos et de vos armes sont des éléments indispensables pour préparer une bonne game. L’inventaire reste limité et il vous faudra choisir entre un équipement optimisé pour le combat ou la récolte de ressources. A noter que chaque mort dans une partie vous fait perdre l’ensemble de vos équipements et ressources obtenus. Arc Raiders ne pardonne pas et reste un jeu assez punitif. Dans le jeu, ce ne sont pas les humains dont il vous faudra faire attention mais les robots. Embark Studios chargé du développement a intégré une IA incroyable et redoutable. Les robots vous traquent à chaque instant et sont capables de vous détecter si vous émettez n’importe quel bruit. Des boss de zones sont aussi présents sur chacune des cartes et il vous faudra vous allier avec le maximum d’équipes pour en venir à bout si vous souhaitez obtenir des plans pour le craft et obtenir de nouveaux équipements et armes légendaires. Concernant l’extraction, il vous faudra regarder votre carte pour connaître les lieux de rendez-vous. Cependant il faut faire attention car certains moyens d’extraction demandent du temps pour s’ouvrir et émettent un son qui attire les robots et les joueurs. D’autres moyens plus discrets sont disponibles mais demandent des ressources ou des clés spécifiques pour s’ouvrir et mettre fin à la game.
Arc Raiders est une excellente découverte et si vous êtes adeptes de jeux multijoueurs je vous le recommande chaudement. Embark Studio avait fait déjà très fort en proposant The Finals qui avait su plaire aux fans de fast-fps compétitif et monte d’un cran avec un jeu d’extraction-shooter de qualité. Si le multi ne vous intéresse pas, il est possible de jouer en solitaire et d’avancer dans le scénario sans soucis. Cependant l’aspect social est mis en avant et j’ai trouvé sympa de nouer des amitiés avec des étrangers ou de m’allier avec des ennemis lors de moments difficiles. Arc Raiders propose une expérience unique et permet aux néophytes du genre d’embarquer dans une expérience sociale incroyable.
Team effort Based at the University of Innsbruck, Ben Lanyon’s group has created a novel qubit register by trapping ten ions. (Courtesy: Victor Krutyanskiy/University of Innsbruck)
Researchers in Austria have entangled matter-based qubits with photonic qubits in a ten-ion system. The technique is scalable to larger ion-qubit registers, paving the way for the creation of larger and more complex quantum networks.
Ions in motion Each ion (large object) is moved one at a time into the “sweet spot” of the optical cavity. Once there, a laser beam drives the emission of a single photon (small object), entangled with the ion. The colours indicate ion–photon entanglement. (Courtesy: Universität Innsbruck/Harald Ritsch)
Quantum networks consist of matter-based nodes that store and process quantum information and are linked through photons (quanta of light). Already, Ben Lanyon’s group at the University of Innsbruck has made advances in this direction by entangling two ions in different systems. Now, in a new paper published in Physical Review Letters , they describe how they have developed and demonstrated a new method to entangle a string of ten ions with photons. In the future, this approach could enable the entanglement of sets of ions in different locations through light, rather than one ion at a time.
To achieve this, Lanyon and colleagues trapped a chain of 10 calcium ions in a linear trap in an optical cavity. By changing the trapping voltages in the trap, each ion was moved, one-by-one, into the cavity. Once inside, the ion was placed in the “sweet spot”, where the ion’s interaction with the cavity is the strongest. There, the ion emitted a single photon when exposed to a 393 nm Raman laser beam. This beam was tightly focused on one ion, guaranteeing that the emitted photon – collected in a single-mode optical fibre – comes out from one ion at a time. This process was carried out ten times, one per ion, to obtain a train of ten photons.
By using quantum state tomography, the researchers reconstructed the density matrix, which describes the correlation between the states of ions (i) and photons (j). To do so, they measure every ion and photon state in three different basis, resulting in nine Pauli-basis configurations of quantum measurements. From the density matrix, the concurrence (a measure of entanglement) between the ion (i) and photon (j) was found to be positive only when i = j, and equal to zero otherwise. This implies that the ion is uniquely entangled with the photon it produced, and unentangled with the photon produced by other ions.
From the density matrix, they also calculate the fidelity with the Bell state (a state of maximum entanglement), yielding an average 92%. As Marco Canteri points out, “this fidelity characterizes the quality of entanglement between the ion-photon pair for i=j”.
This work developed and demonstrated a technique whereby matter-based qubits and photonic qubits can be entangled, one at a time, in ion strings. Now, the group aims to “demonstrate universal quantum logic within the photon-interfaced 10-ion register and, building up towards entangling two remote 10-ion processors through the exchange of photons between them,” explains team member Victor Krutyanskiy. If this method effectively scales to larger systems, more complex quantum networks could be built. This would lead to applications in quantum communication and quantum sensing.
Connexion
