Black Hole Paradoxes Reveal a Fundamental Link Between Energy and Order

The physics of black holes has led to the discovery of a basic link between entropy and energy. The idea began when theoreticians spotted a paradox about Hawking radiation, Stephen Hawking’s calculation that black holes must lose mass over an extremely long time. But if a black hole is even slightly electrically charged, after shrinking for eons it will get to a point at which its electric charge is extremely concentrated — which should prevent it from shrinking further, and perhaps even lead it to split into two smaller black holes. While studying this problem, theoretical physicists stumbled on a formula linking any object’s energy to its entropy — a measure of the number of ways an object’s parts can be rearranged without changing its state.

Astronomers find 'missing' baryonic matter

Astronomers have detected much of the Universe’s ordinary matter, which had long been missing from accounts of its total mass. Not ‘dark matter’ — the mysterious, invisible stuff that makes up the majority of the Universe’s contents. This is normal matter, but it’s spread so sparsely across intergalactic space that more than three-quarters of it is almost undetectable. Using an array of 36 radio telescopes in remote Western Australia, researchers analysed the light from 6 fast radio bursts (FRBs), unusually energetic events that last just milliseconds and originate in other galaxies. The spectrum was sensitive enough to reveal the exceedingly thin matter that the FRBs met in their travels.

Balls of moss move like a flock

Squishy pillows of moss appear to slowly move across glaciers in a coordinated fashion, researchers have found. In a long-term study in Alaska, researchers tagged the rolling ‘glacier mice’ to monitor their motion. The herd seems to move in unison, at a speed of about 2.5 centimetres per day. Their motion didn’t align with the prevailing winds, and they weren’t rolling down a slope — so what propels them is still a mystery.

‘Molecular movie’ shows how electrons rearrange to kick-off a chemical reaction

Scientists in the US and UK are the first to observe electrons rearrange their positions in molecules during the early stages of a light-driven chemical reaction. They did so by firing ultrashort light and X-ray pulses at the molecules to create “movies” of electron motion. The technique promises to shed further light on chemical processes such as bond making and breaking. Their method could also be used to study other ultrafast processes in physics, chemistry, and biology.

Bumblebees Bite Plants to Induce Flowering

When pollen is scarce, bumblebees have their way of extorting more from plants. The insects bite into leaves with their mandibles and proboscises to induce flowering up to one month earlier than normal. Chemical ecologists spotted the unusual behaviour in Bombus terrestris during an unrelated laboratory experiment. Artificial cuts were not as effective, suggesting that some chemicals in the insects’ saliva could play a part.

A planet is born

Astronomers have captured stunning images of a planet forming at the heart of a spiralling disc of gas and dust near AB Aurigae, a star located around 520 light years from Earth. The snap was taken using a near-infrared camera on the Very Large Telescope in Chile. To get better contrast, researchers used a ‘coronagraph’ to block out the star’s light. But even then, it isn’t possible to glimpse the baby planet itself.

A major reboot for carbon dating

Radiocarbon dating is due to be recalibrated using a slew of new data from around the world, including those from tree rings, lake and ocean sediments, corals and stalagmites. The result could have implications for the estimated ages of many finds — such as Siberia’s oldest modern human fossils, which according to the latest calibrations are 1,000 years younger than previously thought.

Corkscrew light promises higher optical-communication data rates

Researchers have demonstrated that a photonic device can produce twisted pulses of light, meaning that their electromagnetic waves swirl in a vortex. The ring-shaped, microscopic ‘tunable vortex microlaser’ is a step towards faster optical communications. Contrary to the properties of light that are commonly used to encode information — wave phase and amplitude — vortices come in discrete types. This makes it harder to mistake one phase for another, which could help to increase the capacity of optical fibres.

Ancient genomes unravel history of East Asia

The first large ancient-genome studies of East Asia suggest that many of its inhabitants descend from two once-distinct populations. Two research groups analysed dozens of genomes from individuals who lived in the region, including what is now China, between 9,500 and 300 years ago. The genomes show that the two populations remained separate for thousands of years, but over time they began interbreeding. This could solve the mystery of how farming spread through the region — it was adopted as farmers and hunter-gatherers mixed. That’s different from what happened in western Eurasia; ancient-genome studies have found that farmers with Middle Eastern ancestry largely replaced hunter-gatherers in Europe.

A glimpse inside δ Scuti stars

Patterns in the vibrations of stars produce a sort of natural music that offers clues to the stars’ internal structure. Astronomers have identified such patterns for some δ Scuti stars, a group for which this music had been elusive.

Pions form a new kind of helium

The ability to make artificial atoms containing exotic particles in place of electrons is giving physicists a new way of probing fundamental interactions. Now researchers have created and interrogated a novel kind of helium atom in which one of the electrons is replaced by a sub-atomic particle known as a pion. The work could shed light on the nature of both pions and neutrinos – tiny, neutral particles for which certain attributes, including mass, remain relatively poorly understood.

Ultracold atomic comagnetometer joins the search for dark matter

A device will use the ‘fifth state of matter’ to search for axions, a relatively neglected candidate for dark matter. The ‘comagnetometer’ consists of two extremely sensitive magnetic-field detectors made from rubidium-87 atoms. The atoms are cooled to near absolute zero to create a Bose–Einstein condensate, so each essentially acts as a single atom. Because they have different spin states that respond differently to magnetic fields, any variation measured by the two detectors could signal the presence of axions.

First full-genome lion family tree

Geneticists have reconstructed the relationships of 20 lions, including several extinct ones, by sequencing their genomes. The results support the idea that lions migrated out of Africa, like humans did. Researchers took samples from both living and dead animals, including two 30,000-year-old cave lions (Panthera leo spelaea) preserved in permafrost in Siberia and Canada’s Yukon territory. The findings reveal details about how lions took over the world — they were once the most globally widespread mammal species — and where genetic diversity has been quashed by shrinking populations.

Closest black hole to Earth found 'hiding in plain sight'

A black hole merely 1,011 light years from our solar system is the closest ever discovered. Astronomers uncovered its presence while studying the binary star system HR 6819 in the constellation Telescopium. The central star orbits a mysterious object every 40 days or so, and the outer star encircles the central star and the object, which has a mass of 4.2 suns. A regular star of that size would shine brightly — so a black hole is the only option.

Dinosaur tail reveals gigantic swimming predator

A new fossil of one of the most unusual dinosaurs, Spinosaurus aegyptiacus, suggests it was a “river monster” powered by a fin-like tail. A new fossil found in Morocco has revealed long spines on the dinosaur’s tail that could have made it work like a giant fin. Hydrodynamic tests with plastic reconstructions of various tail shapes showed that the spinosaurus’s newt-like appendage would produce much more thrust than the tails of other dinosaurs. Spinosaurus aegyptiacus was probably even bigger than Tyrannosaurus rex.