New hints of dark matter, high-energy entanglement, and living Martian concrete

September’s “almost-missed” roundup underscores that tension, presenting four studies that are simultaneously tantalising and tentative. All are drawn from the same Ars Technica feature link.

A tentative dark-matter signal

Physicists estimate that dark matter comprises roughly 85 percent of the universe’s matter, with weakly interacting massive particles (WIMPs) remaining the leading candidate. The LUX-ZEPLIN detector, operating deep in a South Dakota gold mine, reported a single event that could be a WIMP striking a xenon nucleus. The signal lies well below the statistical threshold needed for a discovery claim, and the collaboration openly described it as a “hint” that might be a fluke.

The event’s nuclear recoil energy was higher than standard WIMP models predict, meaning the detector should have also recorded lower-energy recoils—none were seen. The authors note that theorists are already proposing alternatives, such as energy-dependent interaction rates or internal structure within WIMPs. Parallel experiments at Italy’s Gran Sasso (XENONnT) continue data collection, while China’s PandaX detector is still under construction.

Entanglement at the energy frontier

Quantum entanglement, once dubbed “spooky action at a distance,” now underpins quantum computing and precision sensing. In 2023, ATLAS at the Large Hadron Collider (LHC) demonstrated entanglement between top-quark pairs. The new paper extends that work to Z bosons, particles produced when a Higgs boson decays and that decay within a zeptosecond. By reconstructing the angular distribution of the resulting electrons and muons, ATLAS physicists inferred the spins of the parent Z bosons and concluded that the pair was entangled. The authors claim this is the highest-energy entanglement observed to date.

Living concrete for the Red Planet

Transporting construction material to Mars is prohibitively expensive, prompting engineers to seek in-situ solutions. A team from Hong Kong University of Science and Technology mixed Martian-analog sand with a gelatin-yeast binder, the yeast being coated in mussel-inspired adhesive proteins. In simulated Martian pressure and temperature, the mixture was extruded through a nozzle, freeze-drying into a porous foam. The resulting domes, roughly the size of wine corks, exhibited a compressive strength of 10 to 12 megapascals—sufficient for one- to two-story structures on Earth, where gravity is three times stronger than on Mars. The process consumes far less energy than melting regolith into bricks, and the yeast can be reclaimed from deconstructed elements for reuse.

Psychoactive habits in deep time

Archaeologists have long linked hallucinogens to ritual practices, but new evidence pushes the timeline further back. Two early human forager skeletons from Sulawesi, dated to between 25,000 and 16,000 years ago and 7,600–6,300 years ago, display deep, rounded dental grooves. Researchers attribute these marks to prolonged sucking on whole betel nuts, a practice that releases the psychoactive compound arecoline when the seed contacts slaked lime. Laboratory simulations suggest the released arecoline could mildly alter brain function, while the abrasive nature of the nuts likely caused the observed dental wear. The authors propose that the habit may have begun as a pain-relief measure for toothaches, eventually becoming a self-reinforcing cycle.

Our read: The findings broaden the geographic and chronological scope of psychoactive substance use, hinting that early humans experimented with mind-altering agents far earlier and more widely than previously documented.