Category: physics – Page 2
Physicists capture first direct evidence of a Floquet topological state
A new study published in Nature Physics reports the first direct experimental evidence of a Floquet topological state, a novel light-induced phase of matter that, until now, has existed only on paper and in simulations. Topological insulators can conduct electricity along their surface while remaining insulating throughout their bulk. Physicists have spent years developing Floquet engineering, a technique that uses intense, rapidly oscillating light fields to temporarily reshape a material’s electronic structure.
Combining the two ideas seemed like a natural next step: use light to coax an otherwise ordinary material into behaving like a topological insulator on demand. A scheme for realizing such a “Floquet topological insulator” in a semiconductor was proposed in 2011, but pinning down the effect experimentally proved elusive. The predicted state would be short-lived, easy to mistake for other light-matter effects and difficult to disentangle from a material’s ordinary electronic behavior.
Now, researchers have closed that gap using tin telluride (SnTe), a semiconductor that sits close to a topological phase transition. Using femtosecond laser pulses, the team captured direct evidence of the transition.
The global biogeography of passerine songs
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.
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.
How Meta’s AI Models Are Powering the First Wave of Genesis Mission Projects
Lawrence Berkeley National Laboratory — one of the US Department of Energy’s premier research laboratories, known for Nobel Prize-winning work in physics, chemistry, and materials science — operates some of the most advanced scientific facilities on the planet. Among them is the Advanced Light Source (ALS), a football field-sized facility that produces intensely bright beams of X-ray light, allowing researchers to study materials from the atomic and molecular scale all the way to plants. The ALS’s instruments, known as beamlines, generate enormous quantities of data — and as recent facility upgrades have dramatically increased their resolution and speed, the volume of data has exploded beyond what scientists can keep up with.
Magnetic clues inside atomic nuclei help explain how elements form in stars
A scientific team led by Facility for Rare Isotope Beams, or FRIB, has identified the origin of a mysterious excess of low-energy gamma rays emitted by the nucleus zinc-70. They found that the excess is caused by magnetic transitions within the nucleus. The study, “Magnetic Character of the Low-Energy Enhancement in 70 Zn,” published in Nature, sheds light on a long-standing puzzle in nuclear physics and has far-reaching implications for astrophysics.
The collaboration included scientists from 25 institutions in the United States, Canada, Italy, Germany, Norway and South Korea.
Charlie Stross: The World is Complicated. Elegant Narratives Explaining Everything Are Wrong!
Fifteen years ago, I interviewed Charlie Stross about a short story called “Lobsters.”
This spring, a thousand people queued outside Tencent’s Shenzhen headquarters to raise one.
June 2011, Singularity 1 on 1. Back then, “singularity” was a word most people filed under astrophysics, not #AI. Charlie’s 2001 story “Lobsters,” which grew into Accelerando, was one of the sharpest early maps of what happens when intelligence stops being exclusively biological. Uploaded minds. Post-scarcity economics. Legal personhood for software. An economy run by optimization processes no human fully follows.
He wrote it six years before the iPhone.
Now look at 2026. OpenClaw, the open source agent built by Austrian developer Peter Steinberger, now at OpenAI, became the fastest-growing project in GitHub history. In China, installing it is called 养龙虾, “raising lobsters,” after the red logo. Shenzhen, Wuxi and Changshu rushed out subsidy packages. Retirees, schoolkids and office workers lined up for help. A grey market of house-call technicians appeared within days.
Any connection to Charlie’s story? None. The logo is a claw pun on Claude.
Philosophy Of Physics (@PhilosophyOfPhy) on X
The continuity equation was not the work of a single physicist. Its development grew from early hydraulic studies and the work of Daniel and Johann Bernoulli. In the eighteenth century, Jean le Rond d’Alembert produced the first partial-differential expression of mass conservation in fluid motion, and Leonhard Euler soon placed it in the general mathematical framework that became the foundation of modern fluid mechanics. It should therefore not be attributed solely to Giovanni Battista Venturi, whose later work concerned flow through constricted tubes. Its general form is ∂ρ/∂t + ∇·(ρv) = 0 where ρ is fluid density and v is the velocity field. The equation says that mass cannot simply appear or disappear: any change in the amount of fluid inside a region must be explained by fluid entering or leaving it. For steady flow through a pipe, this becomes ρ₁A₁v₁ = ρ₂A₂v₂ If the fluid is effectively incompressible, its density remains constant, giving the familiar form: A₁v₁ = A₂v₂ The meaning is simple. The same volume of fluid must pass through every section of the pipe each second. When the pipe becomes narrower, the fluid must move faster; when it becomes wider, the fluid slows down. This equation is fundamental to the study of pipes, nozzles, rivers, aircraft flow, circulation systems and computational fluid dynamics. More broadly, continuity equations appear throughout physics wherever something locally conserved, such as mass or electric charge, moves through space. The equation is not merely about fluids; it is the mathematical language of the principle that what flows into a region must either flow out or remain inside.
