This infinite tiling pattern could end a 60-year mathematical quest

After 60 years of searching, mathematicians might have finally found a true single aperiodic tile — a shape that can cover an infinite plane and never make a repeating pattern. In March, a team of hobbyist and professional mathematicians found a shape that, together with its mirror image, could be used to build infinite aperiodic tilings. The same team has now modified the shape so it doesn’t need its mirror image to create the never-repeating pattern.

Brain–spine interface allows paralysed man to walk using his thoughts

A wireless connection between the brain and the spinal cord allows a paralysed man to walk using his thoughts. Gert-Jan Oskam, whose legs were paralysed after a cycling accident, received a spinal implant in 2018 that generated robotic movement through pre-programmed electrical stimulation. He has now received head implants that detect brain activity and transmit the signal to a backpack computer, which decodes the information and activates the spinal pulse generator. This brain–spine interface gives Oskam full control over the stimulation, so he can walk and climb stairs.

The Closest Living Relative of the First Animal Has Finally Been Found

Ctenophores, also called comb jellies, are the sister group of all living animals, scientists have discovered. The team compared the comb jelly Bolinopsis microptera to sponges — another contender for the most ancient creature on Earth — along with three unicellular relatives of animals. The pattern of genes on the jellies’ chromosomes revealed that they evolved first. That means that early animals were surprisingly complex: they had a well-developed nervous system, and could probably swim around freely.

JWST spots biggest water plume yet spewing from a moon of Saturn

The James Webb Space Telescope (JWST) has spotted Saturn’s moon Enceladus spraying out a huge plume of very cold water vapour, far bigger than any previously seen there. The enormous cloud could carry the chemical ingredients of life: the salty ocean that lies beneath Enceladus’s icy surface is a possible haven for organisms, which could be sustained by hydrothermal vents.

Human evolution has no single birthplace

Humans did not emerge from a single region of Africa, but from several populations that moved around the continent one million years ago and intermingled for millennia. The widely held idea of a single origin of Homo sapiens is based in part on fossil records. Computer modelling and genome data from modern African and European populations revealed that “our roots lie in a very diverse overall population made up of fragmented local populations”, says evolutionary archaeologist Eleanor Scerri. This means human evolution looks more like a tangled vine than a ‘tree of life.’

Blogger Comments:

Where did the local populations come from?

Astronomers capture largest cosmic explosion ever witnessed

Astronomers have observed the most energetic explosion ever: a fireball 100 times the size of the Solar System and 2 trillion times brighter than the Sun, which has existed for 3 years. The event, dubbed AT2021lwx, might have been caused by an enormous star or cloud of gas being gobbled up by a black hole. The reason why night hasn’t been turned to day here on Earth is that the party is happening 2.5 billion parsecs away. It’s not the brightest event ever seen — that would be the γ-ray burst known as GRB 221009A — but that lasted only a few minutes.

First human ‘pangenome’ aims to catalogue genetic diversity

The first draft of a human ‘pangenome’ has been published. Unlike the first complete human genome sequence, which was derived mostly from the DNA of just one person, the pangenome is drawn from 47 people from around the globe, including individuals from Africa, the Americas, Asia and Europe. More genomes are being added — 350 will be analysed by mid-2024. They will allow geneticists to identify variations in the genomes of diverse populations and investigate links between genes and disease.

Physicists create long-sought topological quantum states

An interlocked ring pattern of virtual exotic particles called non-Abelian anyons — or nonabelions for short — has been created in a quantum computer for the first time. The particles’ paths form Borromean rings, three interlocking rings that can’t be pulled apart but don’t contain any linked pairs. The rings exist only as information inside a quantum computer. They could make the machines more robust to perturbations that create errors in their calculations.

Language model builds better antibodies

A protein language model, a generative artificial intelligence similar to ChatGPT, can improve antibody therapies against viruses such as COVID-19, Ebola and influenza. The models suggested changes to existing antibody therapies that boosted their ability to recognise and block the proteins that viruses use to infect cells. Many of the alterations were outside the regions that are usually the focus of engineering efforts.

New organelle discovered inside animal cell

Biology textbooks look set for an update: researchers have just discovered a new kind of organelle, a tiny organ-like structure inside cells. Researchers made the discovery while investigating the role of phosphate in cell renewal in the guts of fruit flies (Drosophila melanogaster). The new organelle acts as a reservoir for phosphate, a nutrient that is essential for life.

Prehistoric pendant’s DNA reveals the person who held it

A woman who held a deer-tooth pendant some 20,000 years ago left her genetic calling card on the ancient treasure. Scientists unearthed the pendant in Denisova Cave in Siberia, Russia, which was once home to several ancient human species, including the Denisovans. To glean details about who made or wore the pendant, researchers coaxed DNA from inside pores of the tooth — without damaging the priceless item — then compared the genetic sequences with other sets of ancient DNA. The woman was a member of our own species, Homo sapiens, and had north Eurasian ancestry.

Mind-reading machines are here

Scientists have developed the first non-invasive method of determining the gist of imagined speech, presenting a possible communication outlet for people who cannot talk. The thought-to-speech technology relies on functional magnetic resonance imaging and large language models. Researchers used it to decode imagined speech in volunteers while they listened to podcasts. But the results were hit-and-miss, and it was easy to trick the technology. Neuroethicists are split on whether the latest advance represents a threat to mental privacy.

A sapphire Schrödinger’s cat shows that quantum effects can scale up

A sliver of a sapphire crystal close to half the mass of an eyelash has been put in a ‘cat state’: a state of quantum superposition in which its atoms move in two directions at once. This is reminiscent of Schrödinger’s cat, a thought experiment that illustrates quantum superposition by means of a feline that appears to be simultaneously dead and alive until it is observed. The sapphire cat is more than 100 trillion times the mass of the molecules previously put in cat states.

Blogger Comments:

To be clear, the quantum superposition of Schrödinger's Cat is of potential states, alive or dead, one which is instantiated when it is observed.

This research, in contrast, is concerned with actual observed states, not potential unobserved states.

Black-hole image reveals details of turmoil around the abyss

The first image of a black hole blew us away in 2019, showing a ‘ring of fire’ of radio-wavelength emissions swirling around an abyss called M87*. Now, a machine-learning algorithm maximises the resolution of the image to show a substantially thinner ring. And fresh data reveal that a stupendously bright jet of superheated matter, which was observed long before the black hole was imaged, actually emerges from the ring. Astronomers know that jets are ejected from the region surrounding black holes, but it’s still not fully understood how that happens.

James Webb Space Telescope spots planet-making ingredients

The building blocks of planetary formation have been detected in a surprising galaxy, where scientists once thought planets might not emerge. The discovery, made by NASA’s James Webb Space Telescope (JWST), suggests that planet formation could be more common throughout the Universe than previously thought.

Ancient-human genome count surpasses 10,000

More than 10,000 ancient-human genomes have now been sequenced. In 2010, the first ancient-DNA sequence was published, of a man who lived 4,000 years ago. Since 2018, thanks to technological advances, there has been an explosion in the number of ancient genomes sequenced. The vast majority come from people who lived in Europe, Russia and the Middle East.

Comb jellies’ unique fused neurons

Ctenophores, or comb jellies, have surprised scientists with their unusual nervous system: some of their neurons are fused directly to each other. In other animals, neurons are separate cells that communicate through synapses. The discovery suggests that comb jellies’ nervous systems evolved independently of that of all other animals.

Penfold's ‘homunculus’ redrawn to include complex movements

The iconic ‘homunculus’ diagram, which shows how the brain controls individual body parts, has been overhauled to include complex movements. Since the 1930s, the diagram has been used to show a brain region called the primary motor cortex and how it dedicates much more space to some body parts, such as the hands and mouth, than others. Now, hours of magnetic resonance imaging have revealed three interconnected areas that aren’t specific to any one body part. Instead, they connect to parts of the brain that are responsible for critical thinking, maintaining the body’s physiology and planning actions.

Bacterial DNA a key component of vertebrate vision

An ancient gene that our ancestors snatched from bacteria some 500 million years ago became a key component in all vertebrates’ vision. The gene encodes a protein that shuttles light-reactive molecules between cells and is found in all vertebrates — but not in invertebrates. It most closely resembles a class of bacterial genes that encode protein-recycling proteins. Bacteria are known to swap genes, and vertebrates can also incorporate microbial DNA.

Astronomers Spy a Giant Runaway Black Hole’s Starry Wake

Some 40 million years ago, a supermassive black hole escaped the clutches of its host galaxy, leaving a sparkling trail of young stars as it sped away into space. The rogue black hole was first picked up by the Hubble Space Telescope as a faint linear trail. Further observations made with the W. M. Keck Observatory in Hawaii revealed that the streak was a stream of blue stars stretching across a staggering 200,000 light years. The object weighs 20 million Suns and is travelling at more than 1,500 kilometres a second.

Crazy ants’ strange genomes are a biological first

Male yellow crazy ants (Anoplolepis gracilipes) are all chimæras: they are composed of two warring cell lineages with two entirely different sets of genomes. Usually, an organism’s cells all carry the same genes. In yellow crazy ants, some cells carry only maternal and others only paternal genetic material. Chimærism can happen by accident in other animals, but the ants are the first known animal for which this property is an essential aspect of life — although it’s not clear why.

Light waves squeezed through ‘slits in time’

A celebrated experiment in 1801 showed that light passing through two thin slits interferes with itself, forming a characteristic striped pattern on the wall behind. Now, physicists have shown that a similar effect can arise with two slits in time rather than space: a single mirror that rapidly turns on and off causes interference in a laser pulse, making it change colour. The result adds a new twist to the classic double-slit experiment first performed by physicist Thomas Young.

Ancient DNA illuminates Swahili culture’s origins

Genomes point to the diverse origins of Swahili culture, with people carrying a mix of local African, Middle Eastern and South Asian ancestry. Researchers analysed the genomes of 54 individuals buried in Kenya and Tanzania between 1250 and 1800 and found that they were descended from people who began mixing around 1000. Nearly all the East African ancestry seemed to come from women, whereas most of the Asian ancestry was contributed by men from Persia. The results support the oral traditions of Swahili people and dispel the colonial idea that Swahili civilisation is “essentially an Arab civilisation”.

T. rex had lips

Analysis of the teeth and skull of this king of the dinosaurs showed that, unlike its more recent relatives, the crocodiles, Tyrannosaurus rex probably had lips covering its formidable teeth. Most lizards have lips to keep their tooth enamel moist and their delicate dentition protected, and palæontologists have wondered for years whether T. rex was lippy like a lizard or lipless like a croc.

Stressed plants ‘cry’ — and some animals can probably hear them

Thirsty or stressed plants produce ultrasonic clicks that, when processed to make them audible to humans, sound like popping popcorn. Tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum) plants that needed water, or that had recently had their stems cut, produced up to roughly 35 clicks per hour. Well-hydrated and uncut plants made only about one sound per hour. The noises possibly come from air bubbles forming or breaking in the plants’ xylem, the tubes that transport water and nutrients from the roots to the stems and leaves. The sounds could be used to monitor plants in farming and horticulture.

Molecular syringe ferries proteins into human cells

Researchers have repurposed a bacterium’s molecular ‘syringe’ to deliver proteins, such as the genome-editing Cas9 or a cancer-killing toxin, into human cells or the brains of mice. The bacterium Photorhabdus asymbiotica’s injection system usually works only on insect cells. The team modified the structure of the system so that it would recognize other species’ cells and accept payloads including the Cas9 protein, which is five times larger than the syringe’s usual cargo. The method could be a way to administer protein-based drugs and address one of gene editing’s major bottlenecks: delivering the CRISPR–Cas9 system to where it’s needed.

Brightest gamma-ray burst ever detected defies explanation

The brightest γ-ray burst ever detected is defying theoretical expectations. Since the blast of radiation was first spotted in October 2022, astronomers have been studying its afterglow to learn more about the mechanisms behind it. In two new studies, researchers report that the evolution of the radio waves emitted by the enormous burst was much slower than models predicted.

Best view yet of planet in hotly pursued star system

The exoplanet TRAPPIST-1b — one of seven roughly Earth-sized planets in the TRAPPIST-1 system — probably doesn’t have an atmosphere. It’s not surprising: TRAPPIST-1b is the closest to its star and is blasted by four times as much radiation as Earth receives from the Sun. But the work shows the transformational power of the James Webb Space Telescope (JWST) to observe the system, which offers a unique laboratory for studying planetary environments and how they might become suitable for life.

Brain prosthesis improves memory

A ‘memory prosthesis’ seems to boost people’s ability to remember new information. It consists of a deep-brain electrode that records and then mimics the electrical activity pattern of the hippocampus, a brain region that has a crucial role in memory. Twenty-four people, who had already had electrodes implanted to study their epilepsy, volunteered to try the device: it improved their performance in short- and long-term memory tests by up to 54%.

A fish can sense another’s fear

Zebrafish (Danio rerio) become afraid when they see other members of their species in distress. This fear mirroring is regulated by oxytocin: fish that lack the genes to produce and absorb the hormone fail to detect others’ anxiety but regain the ability when they receive an oxytocin injection. Oxytocin has the same effect in mice, and is known to affect humans’ social responses, meaning it’s likely that this empathy mechanism evolved many millions of years ago, before fish and mammals diverged on the tree of life.

Mathematicians have finally discovered an elusive ‘einstein’ tile

Researchers have discovered the first example of a single shape that can cover a surface with an infinite pattern that never repeats. The shape is surprisingly simple: a 13-sided polykite that the team has dubbed ‘the hat’. The hat’s sides can vary in length without it losing the ability to create ‘aperiodic tiling’. Previous examples of aperiodic tilings, such as Penrose tiles, required two or more shapes.

Fruit flies are first known animals that can taste alkaline foods

Fruit flies (Drosophila melanogaster) have surprised researchers with an entirely new taste receptor that allows them to detect alkaline — or basic — substances and avoid toxic meals and surfaces. The flies have an unusual mechanism: a receptor protein that, in the presence of a base, opens a cell-membrane channel through which negatively charged chloride ions escape the neuron. Most sensory receptors involve channels that let positively charged ions flow into the cell. Some studies in people and cats suggest that they, too, experience alkaline as a type of taste.

How humans settled the roof of the world

Modern inhabitants of the Tibetan Plateau are descendants of people who have lived there for 5,000 years. In the biggest study of its kind, researchers sequenced ancient genomes from the remains of 89 individuals unearthed from 29 archæological sites. The genomes suggest that Tibet’s first settlers arrived from the east — in contrast to the rest of South and Central Asia. And researchers saw the increasing prevalence of a variant of the EPAS1 gene that allows people to thrive at high altitudes.

How stem cells make a human brain

Scientists have followed the developmental destiny of individual human brain cells as they progress from stem cells to specialised structures in the brain. In a technical “tour de force”, the team painstakingly purified and classified undifferentiated brain cells from human fœtuses. The cells were injected into mouse brains, and, six months later, the researchers analysed the cellular identities that the cells’ progeny had taken.

Volcano eruption spotted on Venus

Scientists think they’ve spotted a volcano erupting on Venus. Radar images taken 8 months apart by NASA’s Magellan spacecraft in the early 1990s show changes to a volcanic vent that suggest an eruption or magma flow. Venus is covered in volcanoes, and this is some of the strongest evidence yet that at least one of them is still active. Venus doesn’t have plate tectonics that could drive volcanic activity, so it could be caused by heat released from radioactive elements.

Heartbeat May Shape Our Perception of Time, Study Shows

Our perception of time might be in part driven by heartbeats. When 45 students were asked to estimate the length of audio tones, the people with long intervals between their heartbeats perceived the tone as longer, whereas the people with shorter intervals thought it was shorter.

First full brain map of a complex animal

Scientists have mapped all 3,016 neurons and 548,000 connecting synapses in a young fruit fly’s (Drosophila melanogaster) brain. It’s the first complete brain map of a complex animal that can learn, and weigh the risks and benefits of its actions. The only other animals whose brains have been completely mapped are two worm species and the larva of a sea squirt. The neural circuit diagram will help researchers to study how the brain works and neurological diseases.

Asteroid lost 1 million kilograms after collision with DART spacecraft

The asteroid that was deliberately hit with NASA’s Double Asteroid Redirection Test (DART) spacecraft last September lost one million kilograms of rock, gained a 1,000-kilometre-long debris tail and now completes its orbit 33 minutes faster than before the collision. A detailed analysis of what happened when DART smashed into the Great-Pyramid-sized asteroid Dimorphos has revealed how successful this first test of planetary defence really was. The spacecraft hit a spot close to the asteroid’s centre and caused a large spray of rubble to fly outwards, which maximised the impact’s force and added momentum.

Ancient genomes show how humans escaped Europe’s last ice age

European hunter-gatherers holed up in what is now Spain to escape the last ice age, which covered large parts of the continent with glaciers for several millennia. Researchers analysed DNA from 356 individuals who lived in Europe and western Asia between 35,000 and 5,000 years ago. The humans who had sought out the warmer climate on the Iberian Peninsula repopulated Western Europe after the deep freeze ended. This explains how a genetic signature that first showed up in 35,000-year-old remains popped up again in populations tens of thousands of years later — a fact that had remained a mystery until now.

The molecule that kickstarted life

For more than 15 years, scientists have been on a quest: create a functional ‘protoribosome’, a reconstructed version of the protein-building machine that many think might have helped to kickstart life on Earth. The modern ribosome is a key ingredient of life as we know it because it translates genetic information into proteins. At its heart sits a small RNA pocket that some think might be closest to what the very first ribosome looked like. Now, there’s proof that some reconstructed protoribosome-like RNAs can link amino acids — the first step to making proteins. Some scientists say there are other ways for proteins to emerge, without a ribosome. But others are already thinking about repurposing these simple machines to manufacture new kinds of biomolecule.

Physicists Use Quantum Mechanics to Pull Energy out of Nothing

Researchers have shown that energy can be pulled out of empty space by taking advantage of random fluctuations in the quantum fields that fill the vacuum. Physicists exploited quantum entanglement to swap information about the fluctuations, gathered in one place, with energy hoovered up somewhere else. In one experiment, they used radio pulses to link two carbon atoms in a way that effectively teleported energy across microscopic distances for a few milliseconds. A separate experiment tested quantum energy teleportation using several of IBM's superconducting quantum computers.

How dinosaurs got big (and small)

Extinct theropod dinosaurs, which include iconic species such as Tyrannosaurus rex, used more than one evolutionary trick to become big: some had explosive growth spurts, whereas others grew slowly over time. Palæontologists had always assumed that dinosaurs developed like modern birds and mammals, in which larger species grow faster during their most rapid growth period. Now, researchers who analysed growth rings in the shin bones of 42 dinosaur species have discovered that this is true for only 31% of theropods — 28% showed prolonged growth similar to that of modern crocodiles. Of the species that became smaller than their ancestors, 21% did so by shortening their growth spurts and 19% by slowing their growth.

Europe’s earliest evidence of the use of bows and arrows

The first Homo sapiens to arrive in Europe might have hunted with bows and arrows, around 10,000 years earlier than was thought. In a 54,000-year-old-cave in southern France, alongside a H. sapiens tooth and tools, researchers found hundreds of stone points resembling arrowheads — the smallest of which were so tiny that they would have had enough force to kill an animal only if they were shot with a bow. The technology could have been unique to humans: Neanderthals might have inhabited the area at the same time, but there is no evidence that they also took up archery.

Blogger Comments:

Neanderthals were humans, and absence of evidence is not evidence of absence.

Quakes reveal secrets of Earth’s inner core

Measurements of earthquake reverberations have revealed that our planet’s inner core — a solid ball of iron nickel — has two distinct layers made mainly of differently structured iron crystals. The way these oscillations are distorted as they bounce back and forth through the centre of the planets allowed his team to figure out the core’s structure. The finding will help researchers to understand how the core formed millions of years ago and what role it might have had in shaping the magnetic field.

Snakes' hearing ability

Researchers have dispelled the myth that snakes are deaf to airborne sound and can ‘hear’ only ground vibrations. Snakes were placed in a soundproofed room, and sounds with different frequencies were played on speakers. Death adders (Acanthophis), taipans (Oxyuranus) and brown snakes (Pseudonaja) tended to back away from the source of the sound. Woma pythons (Aspidites), however, often approached the speakers — possibly because they’re large nocturnal snakes with few predators, unlike the others. The experiment suggests that snakes can indeed hear sounds in the frequency range and volume of a human voice.

‘Mirror neurons’ fire up during mouse battles

A type of brain cell that is crucial for triggering fights is also activated in mice when they watch other mice fight. Because these cells fire both when an animal observes a behaviour and when it performs that behaviour, some scientists have argued that they might be involved in complex social functions, such as empathy.

Blogger Comments:

"Mirror" neurons are not a 'type' of brain cell. They are the same as other neurons. The claim here is one of function, not form, and the claim of a "mirror" function of neurons rests on the mistaken notion that perceptual categorisation is merely sensory, rather than sensorimotor, as Edelman has theorised and demonstrated with robot simulations.

Microraptor might have hunted like hawks

A crow-sized, feathered dinosaur might have used its feet to snag prey, like modern hawks do. Scientists who compared the fossilised feet of several non-avian dinosaur species found that Microraptor’s protruding toe pads, covered with spiky scales, most resembled those of birds of prey. Other researchers say that toe pads alone aren’t enough to declare that the dinosaur was an aerial hunter. If Microraptor could really fly rather than glide, it would support the debated hypothesis that flight evolved not just in birds, but several times among dinosaurs.

Tree rings reveal drought that might have doomed the Hittites

Three years of severe drought could have contributed to the mysterious collapse of the ancient Anatolian empire of the Hittites 3,000 years ago. Tree rings from ancient juniper timber revealed that there was little rainfall in the area from 1198 to 1196 BC, which could have forced the Hittites to abandon their capital, perhaps dooming the civilisation. Some researchers agree with this assessment, but others think it misses the fact that 1190 BC was the beginning of a 200-year mega-drought that extended from Spain to India.

Sea life bounced back fast after the ‘mother of mass extinctions’

Marine life bounced back surprisingly quickly after the ‘mother of mass extinctions’ killed 81% of marine species 251.9 million years ago. More than 1,000 fossils uncovered in southern China show fish, ancient lobsters and prehistoric crab-like creatures existed just a million years after volcanic activity heated the atmosphere and acidified the oceans. It challenges the idea that complex ecosystems took millions of years to recover in a stepwise fashion, from self-sufficient organisms to apex predators.

Ancient stone tools suggest early hominins dined on hippo

Archæologists in Kenya have unearthed dozens of stone tools scattered around the butchered bones of ancient hippopotamus-like creatures. The site dates to between 2.6 and 3 million years ago, and pushes back the known start of large-animal butchering by early human relatives by at least 600,000 years. The tools are the earliest known example — by around 700,000 years — of Oldowan tools, which became widespread across Africa and Asia. The tools were found alongside the teeth of an ancient human relative from the genus Paranthropus, raising the possibility that Paranthropus, rather than a member of the modern-human genus Homo, used the tools.

How Scientists Are Using AI to Talk to Animals

Digital geographer Karen Bakker says that technology such as digital recording and artificial intelligence will give us the ability to hear and understand animal communication on its own terms.

Fish can recognise themselves in photos, further evidence they may be self-aware

The bluestreak cleaner wrasse (Labroides dimidiatus) seems to recognise its own face — an indication of self-awareness that has so far been found only in humans and a few other species. Each fish was shown composite images: its own head photoshopped onto another fish’s body, and its own body with another fish’s head. The fish were less aggressive towards their own faces, even on another fish’s body, suggesting that this fish forms a mental image of its countenance.

Quantum computing with atoms

In the race to build practical quantum computers, systems based on individual neutral atoms are moving toward the front of the pack. For years, quantum bits (qubits) made from either superconducting loops or trapped ions have been the frontrunners. Increased computing power came from cramming more and more qubits into devices. This has limits because each qubit needs a separate controlling unit, and it can be tricky to get the right qubits to interact at the right time. Now, neutral-atom qubits can be created in bundles of hundreds, held in place and manipulated by laser beams called optical tweezers. Once an underdog, the technology’s pace of improvement has surprised researchers.