Gravitational lensing of galaxy cluster Abell 2390. (ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi)The fabric of space and time is not exempt from the effects of gravity. Plop in a mass and space-time curves around it, not dissimilar to what happens when you put a bowling ball on a trampoline.This dimple in space-time is the result of what we call a gravity well, and it was first described over 100 years ago by Albert Einstein's field equations in his theory of general relativity. To this day, those equations have held up. We'd love to know what Einstein was putting in his soup. Whatever it was, general relativity has remained pretty solid.One of the ways we know this is because when light travels along that curved space-time, it curves along with it. This results in light that reaches us all warped and stretched and replicated and magnified, a phenomenon known as gravitational lensing. This quirk of space-time is not only observable and measurable, it's an excellent tool for understanding the Universe. READ MORE...
The nearest single star to the Solar System has just yielded up a rare and wonderful treasure.
Around a red dwarf known as Barnard's star, which lies just 5.96 light-years away, astronomers have found evidence of an exoplanet.
And not just any exoplanet. This fascinating world, known as Barnard b, is tiny, clocking in with a minimum mass of 37 percent of the mass of Earth. That's a little shy of half a Venus, and about 3.5 Marses.
The reason it's so marvelous is that tiny exoplanets are really, really hard to find. Although Barnard b is not habitable to life as we know it, its discovery is leading us closer to the identification of Earth-sized worlds that may be scattered elsewhere throughout the galaxy. READ MORE...
An expedition to a deep-sea ridge, just north of the Hawaiian Islands, revealed a surprise discovery back in 2022: an ancient dried-out lake bed paved with what looks like a yellow brick road.
The eerie scene was chanced upon by the exploration vessel Nautilus, while surveying the Liliʻuokalani ridge within Papahānaumokuākea Marine National Monument (PMNM).
PMNM is one of the largest marine conservation areas in the world, larger than all the national parks in the United States combined, and we've only explored about 3 percent of its seafloor.
Researchers at the Ocean Exploration Trust are pushing the frontiers of this wilderness, which lies more than 3,000 meters below the waves, and the best part is, anyone can watch the exploration.
A highlight reel of the expedition's footage published on YouTube in April 2022 captured the moment researchers operating the deep-sea vehicle stumbled upon the road to Oz. READ MORE...
Outside of the Pantheon in Rome. (Mariordo/Wikimedia Commons/CC-SA-4.0)
The ancient Romans were masters of building and engineering, perhaps most famously represented by the aqueducts. And those still functional marvels rely on a unique construction material: pozzolanic concrete, a spectacularly durable concrete that gave Roman structures their incredible strength.
Even today, one of their structures – the Pantheon, still intact and nearly 2,000 years old – holds the record for the world's largest dome of unreinforced concrete.
The properties of this concrete have generally been attributed to its ingredients: pozzolana, a mix of volcanic ash – named after the Italian city of Pozzuoli, where a significant deposit of it can be found – and lime. When mixed with water, the two materials can react to produce strong concrete. READ MORE...
Deep beneath our feet, at a staggering depth of over 5,100km, lies Earth's inner core — a solid ball of iron and nickel that plays a crucial role in shaping the conditions we experience on the surface. In fact, without it we'd be unlikely to even exist.
But despite its significance, it's a bit of a puzzle how it formed and developed. We don't even know how old it is. Luckily, mineral physics is bringing us closer to solving the mystery.
The inner core is responsible for Earth's magnetic field, which acts like a shield, protecting us from harmful solar radiation. This magnetic field might have been important for creating the conditions that allowed life to thrive billions of years ago.
The Earth's inner core was once liquid, but has turned solid over time. As the Earth gradually cools, the inner core expands outwards at the surrounding iron-rich liquid "freezes". That said, it is still extremely hot, at least 5,000 Kelvin (K) (4726.85°C). READ MORE...
If you travel far enough away from the Sun, the Solar System becomes a lot more populated.
Out past the orbit of Neptune lies the Kuiper Belt, a vast, ring-shaped field of icy rocks. This is where Pluto resides, and Arrokoth, and countless other small objects in the cold and the dark.
These are known as Kuiper Belt objects or KBOs, and astronomers have just found hints of an unexpected rise in their density, between 70 and 90 astronomical units from the Sun, separated by a large, practically empty gap between it and an inner population of KBOs closer to the Sun.
It seems, almost, like there are two Kuiper Belts, or at least two components – something nobody was expecting to find.
"If this is confirmed, it would be a major discovery," says planetary scientist Fumi Yoshida of the University of Occupational and Environmental Health Sciences and Chiba Institute of Technology in Japan.
"The primordial solar nebula was much larger than previously thought, and this may have implications for studying the planet formation process in our Solar System." READ MORE...
The sex of human and other mammal babies is decided by a male-determining gene on the Y chromosome. But the human Y chromosome is degenerating and may disappear in a few million years, leading to our extinction unless we evolve a new sex gene.
The good news is two branches of rodents have already lost their Y chromosome and have lived to tell the tale. A 2022 paper in Proceedings of the National Academy of Science shows how the spiny rat has evolved a new male-determining gene.
How the Y chromosome determines human sex
In humans, as in other mammals, females have two X chromosomes and males have a single X and a puny little chromosome called Y. The names have nothing to do with their shape; the X stood for 'unknown'.
The X contains about 900 genes that do all sorts of jobs unrelated to sex. But the Y contains few genes (about 55) and a lot of non-coding DNA – simple repetitive DNA that doesn't seem to do anything. But the Y chromosome packs a punch because it contains an all-important gene that kick-starts male development in the embryo.
At about 12 weeks after conception, this master gene switches on others that regulate the development of a testis. The embryonic testis makes male hormones (testosterone and its derivatives), which ensures the baby develops as a boy.
This master sex gene was identified as SRY (sex region on the Y) in 1990. It works by triggering a genetic pathway starting with a gene called SOX9 which is key for male determination in all vertebrates, although it does not lie on sex chromosomes. READ MORE...
Since mindfulness is something, you can practice at home for free, it often sounds like the perfect tonic for stress and mental health issues.
Mindfulness is a type of Buddhist-based meditation in which you focus on being aware of what you're sensing, thinking, and feeling in the present moment.
The first recorded evidence for this, found in India, is over 1,500 years old. The Dharmatrāta Meditation Scripture, written by a community of Buddhists, describes various practices and includes reports of symptoms of depression and anxiety that can occur after meditation.
It also details cognitive anomalies associated with episodes of psychosis, dissociation, and depersonalisation (when people feel the world is "unreal").
In the past eight years there has been a surge of scientific research in this area. These studies show that adverse effects are not rare.
A 2022 study, using a sample of 953 people in the US who meditated regularly, showed that over 10 percent of participants experienced adverse effects which had a significant negative impact on their everyday life and lasted for at least one month.
According to a review of over 40 years of research that was published in 2020, the most common adverse effects are anxiety and depression. These are followed by psychotic or delusional symptoms, dissociation or depersonalization, and fear or terror. READ MORE...
Paleontologists in South Africa said they have found the oldest known burial site in the world, containing remains of a small-brained distant relative of humans previously thought incapable of complex behavior.
Led by renowned paleoanthropologist Lee Berger, researchers said in 2023 they had discovered several specimens of Homo naledi – a tree-climbing, Stone Age hominid – buried about 30 meters (100 feet) underground in a cave system within the Cradle of Humankind, a UNESCO world heritage site near Johannesburg.
"These are the most ancient interments yet recorded in the hominin record, earlier than evidence of Homo sapiens interments by at least 100,000 years," the scientists wrote in a series of preprint papers published in eLife.
The findings challenge the current understanding of human evolution, as it is normally held that the development of bigger brains allowed for the performing of complex, "meaning-making" activities such as burying the dead.
The oldest burials previously unearthed, found in the Middle East and Africa, contained the remains of Homo sapiens – and were around 100,000 years old.
Those found in South Africa by Berger, whose previous announcements have been controversial, and his fellow researchers, date back to at least 200,000 BCE. READ MORE...
Our Solar System is a pretty busy place. There are millions of objects moving around – everything from planets, to moons, to comets, and asteroids. And each year we're discovering more and more objects (usually small asteroids or speedy comets) that call the Solar System home.
Astronomers had found all eight of the main planets by 1846. But that doesn't stop us from looking for more. In the past 100 years, we've found smaller distant bodies we call dwarf planets, which is what we now classify Pluto as.
The discovery of some of these dwarf planets has given us reason to believe something else might be lurking in the outskirts of the Solar System. READ MORE...
To those who have kept tabs on nuclear fusion research the past decades beyond the articles and soundbites in news outlets, it’s probably clear just how much progress has been made, and how many challenges still remain.
Yet since not that many people are into plasma physics, every measure of progress, such as most recently by the South Korean KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak, is met generally by dismissive statements about nuclear fusion always being a certain number of decades away.
Looking beyond this in coverage such as the article by Science Alert about this achievement by KSTAR we can however see quite a few of these remaining challenges being touched upon.
Recently KSTAR managed to generate 100 million degrees C plasma and maintain this for 48 seconds, a significant boost over its previous record from 2021 of 30 seconds, partially due to the new divertors that were installed. READ MORE...
Scientists have long been on the lookout for 'glueballs', which are bound states of subatomic gluon particles on their own, without any quarks involved. Now, we may just have found them, hiding away in a particle accelerator experiment.
It promises to be a hugely significant breakthrough in physics, but for the benefit of everyone without a PhD in the subject, we'll start at the beginning. The main job of gluons is to hold quarks in place and keep atoms stable – quarks being the building blocks that make up protons and neutrons.
This role makes the gluon part of the strong nuclear force – one of the four fundamental forces of nature that hold the laws of physics together, along with gravity, electromagnetism, and the weak nuclear force. READ MORE...READ MORE...
With a name that means 'little brain' in Latin, the cerebellum comprises just 10 percent of the entire brain's mass. Don't let that small size fool you, though; with more than three-quarters of the brain's neurons packed within that small space, there's a lot going on inside.
Traditionally it's thought this part of the nervous system located at the base of the skull is mostly concerned with coordinating motor functions like balance and movement. Now new research backs up a hypothesis that's gathering momentum: it also plays a key role in learning.
In this new study, researchers from the University of Pittsburgh and Columbia University wanted to build on previous research identifying the cerebellum's posterior-lateral region as playing a role connecting what we see to the movements we make. READ MORE...
Why did humans take over the world while our closest relatives, the Neanderthals, became extinct? It's possible we were just smarter, but there's surprisingly little evidence that's true.
A new, precise measurement of the expansion rate of the Universe is in, and it's serving up a huge cosmic pickle.
Using Hubble data and new observations from the James Webb Space Telescope (JWST), a team led by physicist Adam Riess of Johns Hopkins University has confirmed that previous measurements are correct after all, despite years of debate.
Based on immense distances from our Solar System to Cepheid variable stars and Type Ia supernovae, which are used to create a 'cosmic distance ladder', our Universe does indeed appear to be expanding at 73 kilometers per second per megaparsec – a rate known as the Hubble constant. READ MORE...
The story of how life started on Earth is one that scientists are eager to learn. Researchers may have uncovered an important detail in the plot of chapter one: an explanation of how bubbles of fat came to form the membranes of the very first cells.
A key part of the new findings, made by a team from The Scripps Research Institute in California, is that a chemical process called phosphorylation may have happened earlier than previously thought.
This process adds groups of atoms that include phosphorus to a molecule, bringing extra functions with it – functions that can turn spherical collections of fats called protocells into more advanced versions of themselves, able to be more versatile, stable, and chemically active. READ MORE...
We finally know what brought light to the dark and formless void of the early Universe.
According to data from the Hubble and James Webb Space Telescopes, the origins of the free-flying photons in the early cosmic dawn were small dwarf galaxies that flared to life, clearing the fog of murky hydrogen that filled intergalactic space.
"This discovery unveils the crucial role played by ultra-faint galaxies in the early Universe's evolution," says astrophysicist Iryna Chemerynska of the Institut d'Astrophysique de Paris.
"They produce ionizing photons that transform neutral hydrogen into ionized plasma during cosmic reionization. It highlights the importance of understanding low-mass galaxies in shaping the Universe's history." READ MORE...
Scientists have identified a unique form of cell messaging occurring in the human brain, revealing just how much we still have to learn about its mysterious inner workings.
Excitingly, the discovery hints that our brains might be even more powerful units of computation than we realized.
Back in 2020, researchers from institutes in Germany and Greece reported a mechanism in the brain's outer cortical cells that produces a novel 'graded' signal all on its own, one that could provide individual neurons with another way to carry out their logical functions.
By measuring the electrical activity in sections of tissue removed during surgery on epileptic patients and analyzing their structure using fluorescent microscopy, the neurologists found individual cells in the cortex used not just the usual sodium ions to 'fire', but calcium as well. READ MORE...
Older people in ancient Greece and Rome may not have experienced severe memory problems like many who are aging today.
Researchers in California have combed through a slew of classical texts on human health written between the 8th century BCE and 3rd century CE, and found surprisingly few references to cognitive impairment in older folk.
According to Caleb Finch, who studies the mechanisms of aging at the University of Southern California, and historian Stanley Burstein from California State University, severe memory loss may have been an extremely rare outcome of growing old more than 2,000 years ago. READ MORE...
The ancient Romans were masters of building and engineering, perhaps most famously represented by the aqueducts. And those still functional marvels rely on a unique construction material: pozzolanic concrete, a spectacularly durable concrete that gave Roman structures their incredible strength.
Even today, one of their structures – the Pantheon, still intact and nearly 2,000 years old – holds the record for the world's largest dome of unreinforced concrete.
The properties of this concrete have generally been attributed to its ingredients: pozzolana, a mix of volcanic ash – named after the Italian city of Pozzuoli, where a significant deposit of it can be found – and lime. When mixed with water, the two materials can react to produce strong concrete. READ MORE...
