Science X Newsletter

Dear olivier hartmanshenn,

Here is your customized Science X Newsletter for week 14:

	Cosmologists collaborate to sharpen measurements of the Hubble constant An international collaboration has established a unified, statistically rigorous method for combining different measurements of the Hubble constant, achieving 1% accuracy. The resulting value remains in significant tension—over five standard deviations—with predictions from early-universe models, confirming the persistence of the Hubble tension and highlighting unresolved physics in cosmic expansion.

	Pairs of atoms observed existing in two places at once for the first time Helium atoms have been experimentally observed in a quantum superposition, existing in two places at once while entangled in motion. This achievement, previously demonstrated only with massless photons, confirms that massive particles can display such quantum behavior. The findings provide a new platform for exploring the interplay between quantum mechanics and gravity.

	Unexplained sky flashes from the 1950s: Independent analysis supports their existence Independent analysis of 1950s photographic plates from the Hamburg Observatory confirms the existence of brief, unexplained sky flashes previously detected by the Palomar Observatory. These transients, lasting less than a second and predating artificial satellites, exhibit properties inconsistent with known astrophysical sources, suggesting possible reflection from flat, rotating objects near Earth.

	Global human population is pushing Earth past its breaking point Earth’s current population and consumption patterns have exceeded the planet’s sustainable capacity, intensifying pressures on food security, climate, and ecosystems. Population growth rates began declining in the 1960s, but total numbers are projected to peak at 11.7–12.4 billion by 2070, far above the estimated sustainable level of 2.5 billion. Both population size and consumption drive environmental stress, underscoring the need for urgent changes to resource use and global cooperation to ensure long-term stability.

	Thirty previously unpublished verses by Empedocles discovered on a papyrus from Cairo A 2,000-year-old papyrus from Cairo contains 30 previously unknown verses by Empedocles, providing the first direct textual evidence of his work, particularly on particle effluvia and sensory perception. This discovery clarifies his influence on later thinkers and suggests he anticipated atomist ideas, offering new insights into the development of Greek philosophy.

	Recovery from sudden permafrost collapse ranges from 10 years to a century, study suggests Recovery of vegetation after sudden permafrost collapse varies widely, from about 10 years in low-Arctic regions to up to a century in high-Arctic or high-elevation areas. Recovery time is closely linked to a site's gross primary productivity. While plant cover can return, original species composition is slower to reestablish. Woody plants may help stabilize soil and enhance carbon storage post-collapse.

	Graphene 'scaffold' recruits bone cells and helps the body regenerate fractures Graphene-based scaffolds, combined with chitosan, significantly enhance bone regeneration by acting as bioactive, temporary structures that stimulate cell adhesion, vascularization, and osteogenic differentiation. In rat models, these materials achieved nearly 90% bone repair within one month, outperforming other tested biomaterials. Future applications may include integration with stem cells for improved bone healing.

	Terraforming Mars: Modeling engineered aerosols to warm the planet Modeling of engineered aerosols, such as graphene disks and aluminum rods, in the Martian atmosphere indicates that their global distribution could raise surface temperatures by up to 35°C within 15 Mars years, potentially enabling liquid water. The warming effect is relatively insensitive to release rate and season, but uncertainties remain regarding feedbacks involving water vapor, dust, and aerosol removal processes.

	Cannabis and tobacco use linked to smaller brain volume Cannabis and tobacco use are associated with reduced brain volumes in specific regions, including the amygdala, insula, pallidum, and overall gray matter. Regular use of either substance correlates with accelerated decline in gray matter, and higher tobacco consumption is linked to a smaller hippocampus. These structural changes may impact cognitive and emotional functions.

	Gut bacteria may influence social behavior through smell Gut bacteria in mice produce trimethylamine (TMA), a pungent molecule detected by the TAAR5 olfactory receptor, which influences social behaviors such as aggression and hierarchy formation. Disrupting TMA production or TAAR5 function reduces aggression and delays hierarchy establishment, demonstrating a direct pathway from gut microbes to social behavior via smell. Similar mechanisms may exist in other species, including humans.

	Gravity from positivity: Single massive spin-3/2 particle makes gravity logically inevitable, study claims The existence of a single massive spin-3/2 particle in a quantum theory, under the requirements of causality and unitarity, necessitates the presence of gravity and uniquely determines supergravity structure. Supersymmetry and specific relations among physical constants arise as logical consequences, and for charged particles, the theory enforces charge gauging and g = 2.

	The secrets of black holes and the Higgs mass could be hidden in a 7-dimensional geometry A 7-dimensional Einstein-Cartan gravity model with torsion predicts that black hole evaporation halts at a stable remnant, preserving quantum information and resolving the information paradox. The remnant's structure encodes information in its quasi-normal modes and may contribute to dark matter. Dimensional reduction of this geometry naturally yields the electroweak scale, linking black hole physics to the Higgs mass.

	Gravitational waves as possible candidates for the origin of dark matter Gravitational waves present in the early universe could have contributed to dark matter production by converting into massless or nearly massless fermions, which later acquired mass and became dark matter particles. This mechanism offers a novel explanation for dark matter's origin, distinct from previously explored scenarios, and suggests new directions for theoretical and numerical investigation.

	Tiny African fish caught climbing to the top of a 50-foot waterfall Shellear fish (Parakneria thysi) in the upper Congo Basin have been documented climbing 15-meter waterfalls, using specialized fin pads and muscles to adhere to wet rock. Only individuals under 48 mm can complete the ascent, which takes nearly 10 hours and involves frequent resting. This migration occurs during flooding, likely for habitat recovery or predator avoidance, but faces threats from illegal fishing and habitat loss.

	The depths of Neptune and Uranus may be 'superionic' Simulations indicate that under the extreme pressures and temperatures inside Uranus and Neptune, carbon hydride (CH) may form a quasi-one-dimensional superionic state, where hydrogen atoms move along spiral pathways within an ordered carbon framework. This state could affect heat and electrical conductivity in planetary interiors and informs understanding of exotic matter phases.

	Ripples in spacetime and the universe's most controversial number The Hubble constant, which quantifies the universe's expansion rate, yields conflicting values depending on measurement method: about 67 km s⁻¹ Mpc⁻¹ from the cosmic microwave background and about 73 km s⁻¹ Mpc⁻¹ from supernovae. A new approach using gravitational wave "dark sirens" gives an intermediate value of 69.9 km s⁻¹ Mpc⁻¹, offering an independent constraint and highlighting possible gaps in current cosmological models.

	The most pristine star yet found in the known universe SDSS J0715-7334 is identified as the most pristine star known, with less than 0.005% of the Sun’s metal content and extremely low iron and carbon abundances. This second-generation star, about 80,000 light-years away, provides insight into early star formation and chemical evolution in the universe, being 40 times more metal-poor than the most iron-poor previously known star.

	Ghostly particles: Dark radiation may have masqueraded as neutrinos Cosmological observations interpreted as evidence for strongly interacting neutrinos may instead result from a portion of early-universe neutrinos transforming into dark radiation. This dark radiation, indistinguishable from neutrinos in cosmological data, could explain observed anomalies without conflicting with laboratory constraints and may impact unresolved issues such as neutrino mass and the Hubble tension.

	Spectacular fossil treasure trove pushes back origins of complex animals Fossils from the Jiangchuan Biota in southwest China indicate that many complex animal groups, including early deuterostomes and bilaterians, existed at least 4 million years before the Cambrian Period, pushing back the timeline for animal diversification to the end of the Ediacaran (554–539 million years ago). Exceptional preservation reveals anatomical details and suggests previous fossil gaps may be due to preservation bias.

	Early data from Vera C. Rubin Observatory reveals over 11,000 new asteroids Preliminary observations from the Vera C. Rubin Observatory have identified over 11,000 new asteroids and 380 trans-Neptunian objects (TNOs), including two with highly elongated orbits extending nearly 1,000 AU from the Sun. The survey also found 33 new near-Earth objects (NEOs), none posing a threat. Rubin’s advanced capabilities are expected to significantly expand the known populations of asteroids and TNOs.