US nuclear-fusion lab enters new era: achieving ‘ignition’ over and over

This year, the US National Ignition Facility (NIF) has lived up to its name by achieving ignition using lasers — not once, but four times. Ignition is a nuclear reaction that creates more energy than it consumes, similar to the hydrogen-fusion process that powers the Sun.

DeepMind AI outdoes human mathematicians on unsolved problem

An artificial intelligence (AI) system, called FunSearch, has improved on mathematicians’ previous solutions to problems inspired by the card game Set. Until now, researchers have used AI to solve mathematics problems with known solutions. This time, FunSearch went further than what had already been solved by humans in combinatorics, a field of mathematics that studies how to count the possible arrangements of sets containing finitely many objects.

Australian Indigenous genomes are highly diverse and unlike those anywhere else

Australian Indigenous communities are some of the most genetically distinct people on the planet, with the highest rate of genetic variation outside groups in Africa. A new pair of studies sought permission from 159 Indigenous Australians to add their genetic data to global databases, and found that as much as 12% of structural variants — variations that are at least 50 base pairs in size — are unique to these communities.

‘Biocomputer’ combines lab-grown brain tissue with electronic hardware

A computer that combines laboratory-grown human brain cells with conventional circuits can complete tasks such as voice recognition. Researchers trained the system on 240 recordings of eight people speaking. A machine-learning algorithm decoded the mini brain’s neural activity pattern to identify voices, with 78% accuracy. The technology could one day be integrated into artificial-intelligence systems or used to study neurological disorders.

Quantum-computing approach uses single molecules as qubits for first time

Physicists have used lasers as ‘optical tweezers’ to position molecules so precisely that the molecules can be used as qubits to process quantum information. Pairs of calcium monofluoride molecules were gingerly manoeuvred so that they became entangled and behaved as a single collective quantum system. The molecules were cooled to close to absolute zero, making them almost completely still. When their rotation was completely stopped, they represented the ‘0’ state of the qubit. Meanwhile, molecules allowed to rotate with just one quantum of rotational momentum represented the ‘1’ state. Molecules have some advantages over other qubit candidates, such as atoms. For example, molecules could be pushed into service as ‘qutrits’, which have three possible states: −1, 0 and +1.

‘Wobbly spacetime’ may help resolve contradictory physics theories

A new attempt to reconcile the physics of the very big and very small offers up a testable prediction: time itself might be ‘wobbly’. Physicists have long sought a unifying theory that integrates the spectacularly successful — but mathematically incompatible — general theory of relativity and quantum theory. The “postquantum theory of classical gravity” suggests that space-time is smooth and continuous, not ‘quantised’ into discrete chunks. But it has fluctuations — which could be revealed by precise table-top mass measurements.

Blogger Comments:

This theory is based on misunderstandings such as 'time flows' (dimensions don't flow, processes unfold) and 'curved spacetime' (it is the geodesic trajectory in space that is curved, not spacetime).

Gravitational waves from giant black-hole collision reveal long-sought ‘ringing’

Researchers have found the first evidence that ‘ringing’ vibrations are produced by colliding black holes. Newly merged black holes are lopsided, but quickly settle into the lowest-energy shape, a sphere. In the same way that a bell rings with specific frequencies determined by its shape, the stabilising black hole ‘rings down’, and radiates gravitational waves with frequencies that are determined by its mass and spin. A reanalysis of data from the largest black-hole merger ever detected, in 2019, indicates that it produced a black hole 250 times the mass of the Sun — much more massive than the original analysis suggested.

Dolphins feel electric fields

Bottlenose dolphins (Tursiops truncatus) can sense electricity using the pits left behind when the whiskers they are born with fall out. “Everybody thought these structures are vestigial — so without any function,” said zoologist and study co-author Guido Dehnhardt. His team trained two captive dolphins to place their snouts near submerged electrodes and swim away when they detected an electric field. The researchers found that the dolphins’ sensitivity to electricity was similar to that of platypuses. Electroreception could help the animals to find fish hiding in sand on the sea floor or to navigate the ocean using Earth’s magnetic field.

Tiny robots made from human cells heal damaged tissue

Using cells from the human windpipe, scientists have developed tiny self-propelling robots that might have therapeutic properties. When researchers placed the ‘anthrobots’ on a layer of neural tissue that had been scratched, the neurones underneath completely healed within three days. This suggests the potential for personalised regenerative medicine, say the researchers.

Part of sparrow's brain massively expands in preparation for mating

When it’s time to find a mate, the parts of songbird brains that are responsible for singing get bigger — and then shrink down again at the end of the season. But none do it quite like the Gambel’s white-crowned sparrow (Zonotrichia leucophrys gambelii). In males of the species, a brain area called the HVC nearly doubles in size, expanding from 100,000 neurons to 170,000. How the bird pulls off this feat is still a mystery — but it might one day point to ways of treating anomalies in the human brain.

The most powerful cosmic ray since the Oh-My-God particle puzzles scientists

Scientists have detected the highest-energy cosmic ray since the Oh-My-God particle in 1991. Cosmic rays are high-energy subatomic particles that often originate from a stellar explosion or black hole. The latest turbocharged particle, dubbed Amaterasu, seems to have come from a void-like region in space. One explanation could be that Amaterasu actually came from a different region and scientists’ models of what influences the course of cosmic rays are off. Another possibility is that the rays are produced by unknown physics.

Wi-Fi for neurons: first map of wireless nerve signals unveiled in worms

Researchers have charted a long-distance ‘wireless’ nerve network in Caenorhabditis elegans worms for the first time. The nervous system can be thought of as a web of neurons that pass on messages through direct links, called synapses. But neurons can also communicate over longer distances by releasing molecules called neuropeptides, which are intercepted by other neurons some distance away. Incorporating both ‘wired’ synaptic connections and wireless signalling better predicts how signals travel in the worm than does a model using synaptic connections alone.

Mysterious ‘Tasmanian devil’ space explosion baffles astronomers

Astronomers have observed an unprecedented space explosion that, months after the initial event, briefly flared at peak brightness more than a dozen times. Nicknamed the Tasmanian devil, it is one of several similar events whose cause remains unknown. The phenomena could be failed supernovae — massive stars that run out of fuel and collapse into a dense neutron star or a black hole before they can explode. The flashes could be caused by powerful jets of energy firing from their poles.

Earliest bird signs in southern hemisphere

Footprints preserved in the rocks of Australia’s south coast might have been left by ancient birds 128 million years ago — the earliest evidence for birds in the southern hemisphere. The 27 tracks would have been made when Australia was part of the Gondwana supercontinent; this particular bit of land was close to the South Pole. Features such as widely spread toes and a distinctive perching claw suggest the animals were birds, not dinosaurs.

AI Robot chemist could make oxygen on Mars

A robotic chemist powered by artificial intelligence (AI) can make oxygen from water using only materials found on Mars’s surface. The refrigerator-sized machine separated and analysed ore from Martian meteorites, and then found an effective oxygen-generating catalyst among the more than three million possible compounds — all without human intervention. A similar robot could be sent to Mars to remove the need for astronauts to carry oxygen, or the materials to generate it, from Earth.

Human migrations recorded in lice

One animal has accompanied humans on all of our great migrations: the louse (Pediculus humanus capitis). Its genetics might help to reveal the full extent of our travels. Researchers looked at the genetic variation in lice from around the world and found signs of a genetic link between lice in Asia and those in Central America that might be the mark of ancient humans’ arrival in the Americas. Supporting that theory, louse DNA seems to accurately reflect the known timeline of European settlers mingling with Indigenous Americans.

The rise of brain-reading technology

Prototype brain–computer interfaces have helped paralysed people to speak in their own voices, type at unprecedented speeds and walk smoothly. And companies are working on wearable brain-reading products that aim to help users to control their mental state or to interact with computers. Beyond the hype, researchers are well-aware of the risks: from the spectre of big-brother brain surveillance to the commodification of “the sanctuary of our identity”.

An asteroid with its own moon

NASA’s Lucy spacecraft has spotted the tiny 790-metre asteroid Dinkinesh’s even tinier companion, about 220 metres wide. Lucy is on a 12-year mission to take a close-up look at Trojan asteroids, which orbit the Sun near Jupiter.

Strange blobs in Earth’s mantle are relics of a massive collision

Two mysterious blobs of rock in Earth’s mantle could be remnants of the planetary smash-up that formed the Moon. The formations sit in the layer between the crust and the core, are thousands of kilometres long and are slightly denser than their surroundings. Computer simulations suggest that they are from the protoplanet Theia, which smashed into Earth 4.5 billion years ago. Some of Theia’s remnants were flung into orbit, where they coalesced into the Moon.

The Social Exchange Of Value In Plants

This video shows chemical signals passing along the leaves of an Arabidopsis thaliana plant as it senses the airborne volatile organic compounds, which are released by damaged plants. The signals are carried by calcium ions. The plants’ ability to detect their neighbours’ warning messages allows them to activate defences against herbivores. (Reference: Nature paper)

Lampreys had flesh-eating ancestors

Two superbly preserved Jurassic fossils suggest that the ancestors of lampreys — one of two surviving lineages of the once-diverse group of jawless fishes — were fearsome, flesh-eating predators. The discovery also hints that lampreys have evolved different life strategies over time.

Consciousness is still a mystery

The scientific debate around consciousness is livelier than ever: what it is, where it comes from and whether machines can have it. Cognitive neuroscientist Liad Mudrik reviews three books that tackle these thorny questions. The authors — philosopher Daniel Dennett, geneticist Kevin Mitchell and neuroscientist Joseph LeDoux — agree that consciousness gave humans an evolutionary edge. Dennett and LeDoux argue that consciousness can exist only in biological beings, but Mitchell suggests that artificial systems could follow our evolutionary trajectory: embodiment, sensing, acting, with some motivation and learning abilities, and a drop of indeterminacy. Whether this is a good idea, writes Mudrik, is a different question.

Blogger Comments:

From the perspective of Systemic Functional Linguistic Theory, human consciousness is the construal of experience as meaning and the enactment of the self in social relations as meaning. The content of consciousness is the content plane of language, with mental processes projecting meaning and verbal processes projecting wording. Language provided human consciousness and intelligence, not the reverse.

Did dust from the Chicxulub asteroid impact kill the dinosaurs?

Dust might have been responsible for the deadly dinosaur-killing global winter that came after an asteroid slammed into Earth 66 million years ago. Climate simulations suggest that the impact kicked up enough fine particles to block out the Sun and prevent plants from photosynthesising for up to two years. The dust might have stayed in the atmosphere for some 15 years, which resulted in global temperatures dropping by as much as 15 ℃.

First glimpse of the elusive isotope nitrogen-9

Physicists might have spotted an elusive isotope of nitrogen that stretches the definition of a nucleus. Nitrogen-9’s nucleus is composed of a helium-like core of two protons and two neutrons, surrounded by five ‘unbound’ protons — a wildly unbalanced arrangement that stretches the nuclear glue of the strong force to breaking point. The five untethered protons quickly escape and the isotope lasts a mere 10⁻²¹ seconds. The boundary beyond which an isotope is too lopsided to live is called the ‘drip line’. If the evidence of ⁹N is confirmed, it will test the limit of just where the drip line might be.

Menopausal chimpanzees deepen the mystery of why women stop reproducing

The females in a group of wild chimpanzees (Pan troglodytes) are the first non-human primates to be documented experiencing menopause. Toothed whales, such as orcas (Orcinus orca), are the only other wild mammals in which females are known to live long beyond their reproductive years. In captive animals, this seems to be more common: females in 6 out of 20 mammalian orders for which there are data experience cessation of ovulation. This includes European badgers (Meles meles), house mice (Mus musculus) and horses (Equus caballus). Why only some animals experience menopause is still a mystery.

Mars contains surprise layer of molten rock

In the interior of Mars, a layer of molten rock envelops the liquid-metal core, which is smaller than previously thought. Scientists discovered the unique layer by analysing the seismic energy that vibrated through the planet after a meteorite impact. The seismic waves’ speed depends on the types of material that they are travelling through. The molten-rock layer might be left over from a magma ocean that once covered the planet.

AI ‘breakthrough’: neural net has human-like ability to generalise language

An artificial intelligence (AI) system mimics the human ability to quickly fold new words into an existing vocabulary and use them in fresh contexts. By being programmed to learn from its mistakes, the neural network outperformed the chatbot ChatGPT at making generalisations about language, scoring as well as — and sometimes even better than — human volunteers.

The Moon could be 40 million years older

A lunar rock collected by Apollo 17 astronauts suggests that the Moon formed 40 million years earlier than thought. The Moon was born when a Mars-sized object slammed into Earth around 4.5 billion years ago, although the exact timeline of when the molten Moon solidified remains unclear. A re-analysis of one of these rock samples discovered what might be the oldest lunar material: 4.46-billion-year-old zircon crystals.

How grammar influences perception

Indigenous Australians who speak Murrinhpatha have shown how our mental processes can be shaped by the structure of our language. Murrinhpatha has free word order: subjects, objects and verbs can occur anywhere in a sentence. Eye-tracking studies show that Murrinhpatha speakers shown pictures of an event focus on the elements in a different order than English speakers do — all within milliseconds. Murrinhpatha is now thriving because of elders who survived brutal policies of forced assimilation. But many other Indigenous languages are dying or extinct, threatening to curtail our understanding of the diverse ways that humans can think.

Blogger Comments:

From the perspective of Systemic Functional Linguistics, thinking is the mental projection of the meanings of language. What we perceive is sensory impacts interpreted in terms of the meanings of language.

Brain-inspired chip supercharges AI

A computer chip with “mind-blowing” energy efficiency could speed up artificial intelligence (AI). The computing units in IBM’s NorthPole chip are wired together in a network inspired by connections between parts of the human brain. This eliminates the need to frequently access external memory, which is one of the major bottlenecks for faster processing. It beat existing AI machines by a substantial margin in benchmark image-recognition tests and consumed much less power.

Eight-billion-year journey for energy blast

When the Universe was around half the age it is today, a blast of fast radio waves — maybe caused by the collision of several galaxies — shot out into the void. Some eight billion years later, in 2022, astronomers detected it on Earth. The unusual reading is older and more powerful than we thought fast radio waves could be, and might lead to a better understanding of the parts of the Universe that are currently invisible to our telescopes.

‘Dark photons’ hint at nature of dark matter

Indirect evidence of ‘dark photons’ has been spotted in the shrapnel of thousands of particle-smashing experiments. This could provide a glimpse into the mysterious nature of dark matter — which seems to make up most of the mass of the universe but is almost impossible to observe, other than by its gravitational effects. Dark photons, if they exist, could weakly interact with normal matter, offering a window into the dark sector.

Neanderthals hunted cave lions

A spear mark on the 48,000-year-old skeleton of a cave lion (Panthera spelaea) is the oldest evidence of Neanderthals hunting the ice-age predators. The puncture crater on the big cat’s rib, initially thought to be a bite mark made by another animal, is probably the result of a fatal stab with a wooden spear. And Neanderthal hunters were probably after more than just meat: a set of cave-lion bones from about 190,000 years ago shows that care had been taken to preserve the cat’s paws and claws as part of the pelt.

The largest map of the human brain ever made

More than 3,000 cell types — many of them new to science — have been revealed in the largest-ever atlas of human neurones and other brain cells. One team that contributed to the huge project, which involved hundreds of scientists, sequenced the RNA of more than three million cells. Another uncovered links between certain types of brain cell and neuropsychiatric disorders.

AI reads text from ancient Herculaneum scroll for the first time

A 21-year-old undergraduate student has cracked a method for reading charred, unopenable scrolls from the ancient Roman city of Herculaneum. Luke Farritor trained a machine-learning algorithm on fragments of unrolled scrolls, detecting spots where the ink causes a tiny difference in texture. He then analysed closed scrolls that had been penetrated using X-ray computed tomography scans. The breakthrough could unlock the contents of hundreds of never-before-seen writings that were buried by Mount Vesuvius in October AD 79.

Asteroid sample ferried to Earth is rich in the building blocks of life

Samples of asteroid Bennu that were returned to Earth by the OSIRIS-REx mission contain some of the building blocks of life — carbon and water, trapped inside the crystal structure of clay minerals. And this is just what’s on the surface of the sample container — it hasn’t even been opened yet.

Further evidence points to footprints in New Mexico being the oldest sign of humans in Americas

Fossilised human footprints might be the oldest direct evidence that people lived in the Americas thousands of years earlier than thought — as early as 23,000 years ago. Researchers analysed pollen and sediment from the footprints and found that their ages matched estimates from 2021 that were based on the ages of seeds stuck in the fossils. The finding supports the idea that people skirted down the Pacific coast of the Americas after crossing the Bering land bridge, rather than waiting until ice-age glaciers retreated from inland routes. The timeline is also supported by indirect evidence, such as pendants carved from animal remains, but the footprints in New Mexico are special because they were undoubtedly made by people.

New kind of quantum computer made using high-resolution microscope

A new kind of quantum computer uses a high-resolution microscope to control titanium atoms sitting on a surface. The spins of the atoms’ electrons act as quantum bits (qubits), which are key to performing quantum computations. Researchers used microwave signals from a scanning tunnelling microscope to perform a simple two-qubit operation, which took just nanoseconds — faster than is possible with most other types of qubit. But the approach is unlikely to compete with the leading technologies, which are already being scaled up to hundreds of qubits.

Same-Sex Behaviour Evolved in Many Mammals to Reduce Conflict, Study Suggests

Same-sex sexual behaviour probably evolved independently several times in mammals as a way to smooth out social relationships when they started living in groups. An analysis of more than 6,000 mammalian species found that about 4% exhibited same-sex behaviours — including courtship, mating and forming long-term bonds — and these were particularly prevalent in non-human primate species. The researchers caution that the findings can’t explain the evolution of sexual orientation in humans.

Blogger Comments:

Firstly, evolution doesn't happen 'in order to' (purpose); it happens 'because' (reason).

Secondly, the only thing that survives from generation to generation is genes, and genes are passed on through heterosexual behaviour, not homosexual behaviour, so homosexual behaviour does not 'evolve' in species through natural selection. 

Instead, homosexual orientation can be explained developmentally through chromosomal crossover, or at least, some process of genetic recombination. That is, if a child inherits genes that probabilise sexual attraction from its opposite sex parent, then attraction to its same sex will be probabilised, as when a male inherits from the female, and the female from the male.

CERN experiment confirms antimatter falls down, not up

Antimatter experiences the same force of gravity as regular matter. Observing this simple phenomenon had eluded physicists for decades. Scientists at CERN made a thin gas of antihydrogen and dropped it from the top of a 3-metre-tall vertical shaft — a delicate task, because if the antiatoms come into contact with any regular matter, they both cease to exist.

Brainless box jellies learn from experience

Jellyfish have demonstrated that you don’t need a centralised nervous system to learn by association. Tiny Caribbean box jellyfish (Tripedalia cystophora) can be trained to associate the feeling of bumping into an obstacle with a visual cue, and to use the information to avoid future collisions. Learning happens in the jellies’ rhopalia — structures containing rudimentary eyes plus nerve centres that control swimming pulses.

How worlds are born: JWST reveals exotic chemistry of planetary nurseries

The James Webb Space Telescope (JWST) has turned its gaze to several planet-forming swirls of gas and dust surrounding young stars. Two of these ‘protoplanetary’ disks had large amounts of liquid water that can serve as a raw ingredient for planets forming. Another contained a surprisingly large amount of carbon, which could allow newly born planets to sweep up diverse ingredients. In the debris disc around the star Beta Pictoris, scientists discovered a ‘cat’s tail’ of dust that is probably the aftermath of a massive collision.

These ancient whittled logs could be the earliest known wooden structure

The remains of what might have been a wooden structure built by hominins roughly half a million years ago have been uncovered in Zambia. Researchers can’t definitively identify the possible structure — it might have been a raised platform, a shelter or something else entirely. Whatever it was, it pre-dates the evolution of Homo sapiens by more than 100,000 years.

Jawbone hints at new human species

A 300,000-year-old jawbone discovered in a cave in eastern China could represent a new branch of the human family tree. The bone bears a curious mix of modern and archaic features: it’s thick along the jawline, a feature shared with early human species, and lacks the true chin of Homo sapiens. But the side of the mandible is more reminiscent of that of modern humans. The finding deepens the mystery of which ancient human species inhabited East Asia during the Pleistocene, and whether any of them could be ancestors of modern humans.

‘Weird’ dinosaur prompts rethink of bird evolution

The fossil of a bird-like dinosaur that lived around the same time as Archaeopteryx — considered by many palæontologists to be the first bird — has been found in what is now southeastern China. Fujianvenator prodigiosus adds to mounting evidence that there were plenty of different birds living in the Late Jurassic period. Dinosaurs might have diversified into different kinds of bird to occupy different ecological niches, says palæontologist Hailu You. Fujianvenator’s particularly elongated hindlimbs suggest that it was all about running or wading, instead of flying.

Were these stone balls made by ancient human relatives?

Mysterious, spherical bashed-up rocks litter the archaeological record, popping up at many early human sites. Researchers analysed 150 baseball-sized limestone spheroids from what is now northern Israel and say that the balls were crafted on purpose — rather than by natural processes or being formed over time by being used as hammers, for example.

Black holes keep 'burping up' stars they destroyed years earlier, and astronomers don't know why

Many black holes that consume a star seem to ‘burp up’ energy long after the fact. When the star is ripped apart, some the stellar material forms a swirling accretion disk that orbits the hole. Sometimes, material is flung out from this disk, which is detectable as a wash of radio waves. Astronomers observed 24 star-destroying black holes and were surprised to find radio signals indicating that 10 of them emitted these outflows years after the initial event — although we don’t yet know why.

AI predicts chemicals’ smells from their structures

An artificial-intelligence system can describe how compounds smell simply by analysing their chemical structures. The neural network can provide descriptions, such as ‘grassy’, for hundreds of molecules, including some that don’t exist in nature. Smell is the only sensory input that goes directly from the sensory organ to the brain’s memory and emotional centres without passing through other brain regions — which is why scents can evoke specific, intense memories.

Human ancestors nearly went extinct 900,000 years ago

Roughly 900,000 years ago, climate changes sweeping the globe might have pushed our distant ancestors to the brink of extinction. The unknown human-like species was reduced to just 1,280 breeding individuals, creating a genetic bottleneck that is still detectable in the DNA of modern-day humans. The population didn’t expand for more than 100,000 years, after which it bloomed again and the progenitors of our species and of our extinct relatives, the Denisovans and the Neanderthals, emerged.

Rare oxygen isotope detected at last — and it defies expectations

Physicists have for the first time detected oxygen-28 — an isotope of oxygen that has 12 extra neutrons packed into its nucleus. Scientists have long predicted that this isotope is unusually stable. But initial observations of the ²⁸O nucleus suggest that this isn’t the case: it disintegrates rapidly after creation. If the results can be replicated, physicists might need to update theories of how atomic nuclei are structured.