Physicists at the University of Innsbruck created and observed Bethe strings, quantum bound states that Hans Bethe predicted in 1931. The team cooled caesium atoms to a few billionths of a degree above absolute zero and split the cloud into thousands of narrow one-dimensional tubes. By tuning the interactions from repulsive to attractive, the atoms bound together into clusters of several sizes, some holding six or more particles. The strings survived collisions with one another but fell apart when released into three dimensions, which freed extra energy and confirmed their presence. The results appeared in Nature Communications.
Physicists at the National University of Singapore have built an optical atomic clock from a single lutetium ion and measured its frequency to 19 decimal places. The team reported an uncertainty of 1 x 10^-19, the lowest for any optical clock, in the journal Nature on September 23. Two independently built clocks ran side by side for 200 hours and agreed to within 5.7 x 10^-19, the most precise comparison of its kind. The design is unusually resistant to changes in temperature and magnetic fields. The researchers say such clocks could help redefine the second. Optical clocks are already used in laboratories to test relativity, and national metrology institutes are comparing designs to decide which one should replace caesium.
The Royal Swedish Academy of Sciences awarded the 2026 Nobel Prize in Chemistry to Henri B. Kagan and Kenso Soai for the discovery of non-linear effects and autocatalysis in asymmetric organic synthesis. Their work explains how reactions can be steered toward one of two mirror-image forms of a molecule, a problem that matters for making medicines, flavours and scents. The two share 12 million Swedish crowns, about $1.2 million. The prize is the third of this year's Nobel awards.
The Royal Swedish Academy of Sciences awarded the 2026 Nobel Prize in Physics to Francis Halzen of the University of Wisconsin-Madison. The citation praises his decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin. IceCube uses thousands of light sensors sunk into a cubic kilometre of Antarctic ice and was completed in 2011. In 2013 the collaboration reported the first high-energy neutrinos from beyond the solar system, and later work traced some of them to a blazar. Halzen is the sole recipient of this year's prize.
A new study from UCLA Health finds that patterns of gut bacteria and their chemical byproducts are linked to how quickly a person's brain appears to age. The researchers built a Brain Aging Index using brain scans from generally healthy adults. People with older-looking brains also scored lower on memory, focus and mood tests. Higher brain aging scores were tied to certain bacteria and metabolites, including specific fat molecules and lower levels of a hormone called estetrol. The study is cross-sectional, so it shows associations rather than cause and effect.
Biologists at the University of Massachusetts Amherst measured the calls of 123 bird species and found two that break 120 peak decibels. The bare-throated bellbird, which lives in the Amazon, reached about 131 decibels. The red-legged seriema, found across eastern South America, exceeded 120 decibels. Both are louder than a chainsaw or a jackhammer. The study, published in the journal Evolution, found that louder songs came from bigger birds with wider beaks, but found no clear link between volume and habitat or mating system. The results help explain why some birds call so much louder than others.
Researchers with the ATLAS experiment at CERN's Large Hadron Collider say they have found evidence of the Higgs boson decaying into a virtual photon and a real photon. The pathway is expected in only about one in 10,000 Higgs decays, making it one of the hardest to observe. The result helps physicists test how the Higgs particle interacts with other particles. Teams will collect more data to confirm the finding and sharpen their measurements.
Astronomers report the first radio waves seen coming from an exoplanet, a signal that hints at auroras in another solar system. The detection adds a new tool for studying the magnetic fields of planets beyond our own. In a separate advance, physicists used radioactive lutetium to build what they describe as the most accurate atomic clock ever, keeping time to 19 decimal places. Canada's CHIME telescope also produced a measurement of dark energy after seven years of work, and CERN's ATLAS team found evidence of an extremely rare Higgs boson decay.
A small fossil from Scotland that has been described for nearly 30 years as one of the earliest known reptiles belongs to a much older lineage, according to a study published on 30 September in Nature. Researchers at the American Museum of Natural History, the University of Oxford and the European Synchrotron Radiation Facility rebuilt the specimen, nicknamed Lizzie, in three dimensions. The scans showed internal gills and a fish-like mouth lined with thousands of tiny teeth, identifying it as a derived stem tetrapod rather than an early amniote. The find changes how the fossil can be used as evidence for the move onto land.
NASA and SpaceX are targeting 1 October for the launch of Crew-13 from Cape Canaveral. The Falcon 9 will carry four astronauts in a Dragon capsule that could reach the International Space Station in about seven hours and 50 minutes, which would be the fastest US crewed trip to the outpost on record. Docking is expected around 7 p.m. EDT. The mission was pushed back from September after engineers found an oxidiser leak in Dragon's propulsion system; teams replaced an oxidiser valve and completed readiness reviews.