Although bird songs are classic models for understanding the evolution of vocal communication, their global diversity has long made the development of a unifying framework challenging. By analyzing the acoustic architecture of songs from more than 3,000 passerine species worldwide, we show that this acoustic space can be structured around eight elemental motifs. The differential use of these motifs is driven by a combination of species’ biological traits (social organization, morphology, and mating system) and the physics of sound propagation. In tropical rainforests, environmental filtering for transmission efficiency favors structurally simple motifs, such as flat whistles.
Category: space – Page 26
Extragalactic positron-annihilation hotspots might mean Milky Way produces far more positrons than thought
Positrons—the antimatter counterpart of electrons—are created in high-energy cosmic processes. When normal matter meets its antimatter counterpart, they annihilate, or vanish, and produce a distinctive 511 keV gamma-ray signal. Scientists use this signal to detect where these annihilations occur.
Now, 20 years’ worth of this kind of data has revealed that positron annihilations might be happening in unexpected places and at far greater rates than previously thought. The new study, published in Astronomy & Astrophysics, describes how astronomers are interpreting a new positron annihilation map and whether the results represent true annihilations or just imaging artifacts.
Magnetic fingerprint of a cosmic explosion detected for the first time
Astronomers have made a series of landmark observations of one of the universe’s most violent events. Using the U.S. National Science Foundation Very Large Array (NSF VLA) radio telescope, which is operated by the U.S. National Science Foundation National Radio Astronomy Observatory (NSF NRAO), the team detected polarized light from a gamma-ray burst (GRB) afterglow for the first time at radio wavelengths.
It also marks the first time scientists have detected Faraday rotation in a GRB, a phenomenon in which magnetic fields cause the polarization of light to twist as it travels through space, revealing how the magnetic environment of these explosions interacts with the light they produce. The findings, led by researchers at the University of Arizona and the University of Utah, offer a new window into the extreme physics driving these titanic explosions.
The paper has been submitted to The Astrophysical Journal Letters and is available on the arXiv preprint server.
Quantum dots reveal hidden light waves on metal surfaces
Photographs can reveal things that are otherwise impossible for the naked eye to see, be they distant galaxies or microscopic cells. Researchers at Osaka Metropolitan University have developed a practical and versatile imaging technique that makes another usually invisible phenomenon visible: surface plasmon polaritons (SPPs), light waves that travel along metal surfaces.
The new method, published in the journal Nano Letters, could boost the development of next-generation optical and plasmonic technologies.
SPPs are electromagnetic waves that travel along the boundary between a metal and a dielectric material, such as air or glass. Unlike ordinary light, which spreads freely through three-dimensional space, SPPs remain tightly confined to this interface, allowing them to be guided and manipulated at the nanoscale. This unique property makes them fundamental to emerging technologies including ultrasensitive sensors, optical circuits and quantum devices.
Space Force Wants Commercial Bandwidth for SATCOM Experiments
The Space Force is planning a series of experiments to test concepts for broadening its narrowband SATCOM mission to medium-Earth orbit.
Universal structure of exceptional points revealed in nonlinear light‑based systems
Exceptional points, or EPs for short, are among the phenomena of modern physics. These are special points or locations at which the properties of matter, space or time change. In a new theoretical study, researchers from the Institute for Photonic Quantum Systems (PhoQS) at Paderborn University, in collaboration with researchers from the University of Arizona, have shown that exceptional points in nonlinear systems follow a universal geometric order—something that was previously unclear. Their findings have been published in the journal Nature Communications.
Exceptional points are points in physical systems at which not only two eigenvalues but also the corresponding states merge. Such phenomena occur in so-called non-Hermitian systems, which are characterized, for example, by amplification, loss or interactions with their environment. They are the subject of intensive research in fields including optics, lasers, quantum systems and polariton condensates.
Until now, EPs have mainly been studied in linear systems. In such systems, they can often be described as isolated points in parameter space. However, many real physical systems are nonlinear: Their properties depend on the intensity, occupation or state of the system itself.
Galaxy launches Bitcoin quantum computing initiative, commits up to $5 million in developer grants
Galaxy has launched the Bitcoin Quantum Readiness Initiative, including committing up to $5 million in developer grants.
Anthropic accuses Chinese AI labs of mining Claude as US debates AI chip exports
As one legal analyst noted, the settlement may be seen by the tech industry as simply “a price of conducting business in a fiercely competitive space”—a cost of doing business rather than a genuine deterrent. Meanwhile, the fair-use ruling on training means Anthropic retains the legal right to train on copyrighted works, as long as it doesn’t pirate them to do so.
Anthropic is accusing three Chinese AI companies of setting up more than 24,000 fake accounts with its Claude AI model to improve their own models.
The labs — DeepSeek, Moonshot AI, and MiniMax — allegedly generated more than 16 million exchanges with Claude through those accounts using a technique called “distillation.” Anthropic said the labs “targeted Claude’s most differentiated capabilities: agentic reasoning, tool use, and coding.”
The accusations come amid debates over how strictly to enforce export controls on advanced AI chips, a policy aimed at curbing China’s AI development.
Astronomers Discover Two Super Puff Planets Lighter Than Cotton Candy
Two giant planets lighter than cotton candy are giving astronomers a rare new window into the origins of some of the galaxy’s strangest worlds.
The Strange Case of Elias Thorne, the Imaginary Man AI Chatbots Are Obsessed With
No matter the company, AI chatbots were raving about the same guy named Elias Thorne. He must be pretty fascinating. And he is, at least on paper. Depending on the AI, he’s a lighthouse keeper, a clockmaker, a librarian, an explorer, and the star of countless stories. He’s appeared in books, music listings, YouTube videos, and even health guides. You’d think he was one of the most influential men on the planet.
But he doesn’t exist.
According to reporting by fine folks at 404 Media, researchers at Cornell University may have figured out why large language models invent and keep telling tales of the same fictional man. In a study examining roughly 20,000 AI-generated stories from all the big LLM models, including OpenAI, Anthropic, and Google, the research team found that the same handful of names and occupations kept cropping up. Specifically, names and words like Elias, Mara, Elara, lighthouse keeper, clockmaker, and librarian showed up in 88 percent of stories. Elias the lighthouse keeper appeared in nearly two-thirds of them.