A coordinate transformation devised for an expanding universe leads to new insights into how a collapsing protogalaxy acquires a large magnetic field.
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Humanoid robots master parkour and acquire human-like agility
Humanoid robots, robotic systems with a human-like body structure, have the potential of tackling various real-world tasks that are currently being completed by humans. In recent years, many robotics researchers and computer scientists have been trying to broaden these robots’ capabilities and improve how they move in their surroundings.
A research team at Amazon Frontier AI & Robotics (FAR) and University of California Berkeley (UC Berkeley) recently introduced perceptive humanoid parkour (PHP), a framework that could allow humanoid robots to move with remarkable agility, running, jumping and climbing over obstacles in urban or natural environments. Their proposed approach, outlined in a paper published on the arXiv preprint server, entails training computational models on recordings of humans engaging in parkour, a popular urban sport that allows practitioners to rapidly navigate environments using their agility and body strength.
“While recent advances in humanoid locomotion have achieved stable walking on varied terrains, capturing the agility and adaptivity of highly dynamic human motions remains an open challenge,” wrote Zhen Wu, Xiaoyu Huang and their colleagues in their paper.
Listening to the body’s quietest, yet most dynamic movements with a wearable sensor
The human body continuously generates a rich spectrum of vibrations—often without us ever noticing. Everyday unconscious activities such as breathing, speaking, and swallowing all produce subtle yet distinct mechanical signals. Although these faint vibrations carry valuable information about physiological state, they have long been difficult to capture accurately using conventional wearable devices.
Recently, a research team led by Professor Kilwon Cho of the Department of Chemical Engineering at Pohang University of Science and Technology (POSTECH), along with Ph.D. candidate Kang Hyuk Cho and postdoctoral researcher Dr. Jeng-Hun Lee, has developed a wearable vibration sensor capable of precisely detecting these subtle yet highly dynamic signals, without requiring any external power source. This breakthrough opens new possibilities for wearable medical and health care technologies and demonstrates strong potential as a core sensing platform for next-generation smart devices. The work was published in the inaugural issue of Nature Sensors.
Sounds produced by the human body span a wide range of frequencies. Physiological signals such as breathing, swallowing, and speech typically occur at lower frequencies, while sounds such as coughing or groaning emerge at relatively higher frequencies. Accurately capturing these signals requires precise detection of the minute vibrations transmitted to the skin surface across a broad frequency spectrum.
Can thermal noise train a computer? A new framework points to low-power AI
What if the thermal noise that hinders the efficiency of both classical and quantum computers could, instead, be used as a power source? What if computers could make use of the noise instead of suppressing or overcoming it? These are the goals of a relatively new branch of computing known as thermodynamic computing. A collaboration between researchers at the Molecular Foundry and the National Energy Research Scientific Computing Center (NERSC), both U.S. Department of Energy (DOE) user facilities located at Lawrence Berkeley National Laboratory (Berkeley Lab), is bringing them closer to reality.
In a paper published in Nature Communications, the researchers have proposed a design and training framework for a type of thermodynamic computer that mimics a neural network, which could drastically reduce the energy requirements of machine learning.
Modern computing requires energy: a single Google search, for example, consumes enough energy to power a six-watt LED for three minutes. This is partly because computers must contend with thermal noise—that is, the vibration of charge carriers, mostly electrons, within electronically conductive materials. In classical computers, even the smallest devices, such as transistors and gates, operate at energy scales thousands of times larger than that of this vibration.
Scientists create a hexagonal diamond that could be even harder than the real thing
To misquote a famous song, “Diamonds are industry’s best friend.” Cubic diamond is the hardest mineral on Earth and is used in everything from precision cutting tools to high-performance semiconductors as well as expensive jewelry. But there is a rare and potentially tougher form called hexagonal diamond (HD), which has long been the subject of theories and debate over its actual existence. But now researchers from China claim to have created this elusive form of carbon in the lab.
Hexagonal diamond (also known as lonsdaleite) is usually found at sites of meteorite impacts. But because the quantities are so small and mixed with minerals, some scientists doubted it was a distinct material. In a paper published in the journal Nature, researchers describe how they made a bulk piece of pure HD using extreme pressure and heat.
New LVK catalog adds 128 gravitational-wave candidates, more than doubling detections
When the densest objects in the universe collide and merge, the violence sets off ripples, in the form of gravitational waves, that reverberate across space and time, over hundreds of millions and even billions of years. By the time they pass through Earth, such cosmic ripples are barely discernible.
And yet, scientists are able to detect them, thanks to a global network of gravitational-wave observatories: the U.S.-based National Science Foundation Laser Interferometer Gravitational-Wave Observatory (NSF LIGO), the Virgo interferometer in Italy, and the Kamioka Gravitational Wave Detector (KAGRA) in Japan. Together, the observatories “listen” for faint wobbles in the gravitational field that could have come from far-off astrophysical smash-ups.
Now the LIGO-Virgo-KAGRA (LVK) Collaboration is publishing its latest compilation of gravitational-wave detections, presented in a forthcoming special issue of Astrophysical Journal Letters. From the findings, it appears that the universe is echoing all over with a kaleidoscope of cosmic collisions.
Neutrons reveal magnetic signatures of chiral phonons
Physicists in China have uncovered new evidence that chiral phonons and magnons can interact strongly inside magnetic crystals. Using neutron spectroscopy, a team led by Song Bao at Nanjing University mapped magnetic signatures linked to chiral phonons in a ferrimagnetic material, revealing a previously elusive relationship between lattice vibrations and magnetic excitations. Reported in Physical Review Letters, the results could help researchers better understand how heat, sound and spin interact in quantum materials.
Phonons are collective vibrations of atoms in a crystal lattice which carry quantized packets of sound and heat through a solid. As quasiparticles, they behave somewhat like particles moving through the material and can interact with other excitations. In some cases, phonons also exhibit chirality: where some property of a particle differs from its mirror image.
For phonons, chirality arises when ions move in circular motions as the lattice vibrates, which imparts both an angular momentum and a tiny magnetic moment, which rotates in a plane perpendicular to the phonon’s direction of travel. Crucially, however, the phonon’s properties will vary depending on whether this rotation is clockwise or anticlockwise.
Missing technosignatures? Turbulent plasma may blur ultra-narrow signals before they leave their home star systems
A new study by researchers at the SETI Institute suggests that stellar “space weather” could make radio signals from extraterrestrial intelligence harder to detect. Stellar activity and plasma turbulence near a transmitting planet can broaden an otherwise ultra-narrow signal, spreading its power across more frequencies and making it more difficult to detect in traditional narrowband searches. The paper is published in The Astrophysical Journal.
For decades, many SETI experiments have focused on identifying spikes in frequency—signals unlikely to be produced by natural astrophysical processes. But the new research highlights an overlooked complication: even if an extraterrestrial transmitter produces a perfectly narrow signal, it may not remain narrow by the time it leaves its home system.
In most technosignature searches, scientists account for distortions that happen as radio waves travel across interstellar space. This study focuses on what can happen closer to the source. Plasma density fluctuations in stellar winds, as well as occasional eruptive events such as coronal mass ejections, can distort radio waves near their point of origin, effectively “smearing” the signal’s frequency and reducing the peak strength that search pipelines rely on.