Toggle light / dark theme

Get the latest international news and world events from around the world.

Log in for authorized contributors

Largest-ever survey of physicists puts Standard Model of cosmology under scrutiny

The largest-ever survey of physicists from around the world—released today—shows a distinct lack of consensus across many of physics’s most important questions, from the nature of black holes and dark matter, to the still-incomplete unification of Einstein’s theory of gravity with quantum mechanics.

Even the best theory of the universe’s expansion, known as the standard model of cosmology or ΛCDM (Lambda Cold Dark Matter), did not attain majority support. This surprising outcome is perhaps due to results from the Dark Energy Spectroscopic Instrument (DESI) last year, which hinted that dark energy may change over time, in opposition to the standard model’s conviction that dark energy remains constant.

But that wasn’t the only surprising outcome. The survey doesn’t seem to find much agreement anywhere.

Atoms vibrate on circular paths—with an unexpected twist

An international team of researchers, including scientists from HZDR and Fritz Haber Institute of the Max Planck Society, for the first time directly observed how angular momentum is transferred and conserved within a crystal lattice. Using intense terahertz laser pulses, the researchers were able to selectively control these processes, which unveiled a surprising effect: During the angular momentum transfer, the direction of rotation reverses—caused by the rotational symmetry of the material.

The results, published in Nature Physics, provide new insights into the foundation of magnetism and open up possibilities for tailored control of quantum materials.

Conserved quantities such as energy, momentum, and angular momentum determine the fundamental laws of nature. In a closed system, these quantities are always conserved: they cannot be created or destroyed, only transformed or transferred. While angular momentum is familiar in everyday life through rotating carousels or riding a bicycle, it plays a central role at the quantum level—for example, as the fundamental origin of magnetism.

Open-source ‘digital twin’ enables end-to-end testing of applications over wireless

Researchers at the University of California San Diego have developed an open-source “digital twin” of a wireless network, giving graduate students, startups and other innovators a free, easy-to-use way to test new technologies and get fast, realistic feedback. The platform could help accelerate the pace of wireless innovation.

“We are building a software replica of everything that happens when you use your phone, from the wireless signals traveling through the environment to the cellular network and apps that deliver data and services like video and Instagram,” said Dinesh Bharadia, associate professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering, an affiliate of the UC San Diego Qualcomm Institute and senior author of the paper.

“This will help industry and academia build new protocols and algorithms faster using software and AI, with less need for real-world experiments.”

How temperature changes light: New model could guide smarter LEDs, sensors and photonic devices

Technion researchers have developed, for the first time, a comprehensive physical model explaining how the properties of a radiating material, including absorption, emission, and quantum efficiency, affect the fundamental characteristics of the light it emits as a function of temperature. In essence, the emitted light changes its color, intensity, and randomness according to the material’s properties and its temperature. The discovery was published in Optica and opens new possibilities for designing advanced light sources, optical sensors, and thermally based photonic systems.

The research was led by M.Sc. student Tomer Bar-Lev and Prof. Carmel Rotschild from the Faculty of Mechanical Engineering and the Russell Berrie Nanotechnology Institute at the Technion. According to the researchers, the central phenomenon examined in this work is photoluminescence, a process in which a material emits light in response to incident illumination. In this phenomenon, light particles (photons) are absorbed by the material and re-emitted, forming the basis of many technologies, including LED lighting and optical sensors.

The Technion researchers demonstrated that the influence of fundamental physical laws formulated more than a century ago is far broader than previously thought.

New quantum protocol breaks distance and speed barriers in fiber networks

Scientists at the University of Science and Technology of China have successfully deployed a multi-mode quantum relay network, achieving matter–matter entanglement over 14.5 kilometers, according to media reports.

The system, known as Xinghan-2, was detailed in the journal Nature Photonics on May 7. It addresses a key bottleneck in quantum communication by achieving both high transmission rates and high fidelity at the same time.

Quantum relays are seen as essential for the future quantum internet, as they help prevent signal loss over long distances by dividing communication channels into shorter segments. Previous approaches often involved a trade-off between the high speeds of single-photon interference and the high precision of two-photon interference.

Giving X-ray vision a sense of direction

Whether in tooth enamel or in nanomaterials made of silicon, the orientation of tiny internal structures often determines the properties of a material. A new X-ray method can even make this nano-order visible when the structures are actually too small to be imaged directly. The method was developed by an international team led by the Helmholtz Center Hereon, and it opens up new possibilities to investigate materials and biological structures. The research is published in the journal Light: Science & Applications.

In medical X-ray imaging, the picture is created by the varying attenuation of X-rays in the body. In order to examine materials or biological tissue in detail, experts use advanced techniques that provide additional information, such as dark-field imaging. This technique exploits the fact that X-rays are scattered, i.e., deflected, at internal interfaces and irregularities. “The scattering reveals a lot about internal structures that are not directly visible in the actual image,” explains Hereon researcher Sami Wirtensohn, first author of the study.

To make these fine structures visible, the dark field method blocks the direct X-ray beam. This allows the detector to capture only the radiation scattered inside the sample. Until now, this method has only been able to show that such structures exist, but not how they are spatially aligned.

This Magnetic Field Trick Creates Entirely New Forms of Matter

Scientists have shown that changing magnetic fields in precise ways can create exotic quantum matter that does not normally exist. The discovery could eventually lead to more reliable quantum technologies and powerful new computing systems.

Quantum technology is widely seen as one of the most promising future tools for processing massive and complicated amounts of information. Although most quantum systems are still confined to laboratories and research facilities, scientists are steadily working toward applications that could eventually impact industries across the economy.

Magnetic fields and exotic quantum states.

/* */