Ars Technica Science

Our leading hypothesis for how our memories are stored is that when you learn something, the connections among neurons involved get stronger and physically larger, and that constitutes the memory. The trouble is that these connections significantly change over time—they’re plastic. “If you compare the arrangement of these connections on day one with the same on day four or five, it's very, very different," says Kazumasa Tanaka, a neuroscientist at the Okinawa Institute of Science and Technology

Pause for a moment and listen. What do you hear? Chances are, somewhere in the background, is the ever-present hum of a road. More than 4.2 million miles of public roads crisscross the lower 48 states—enough to reach the Moon and back almost nine times. This vast network of roads spiderwebs its way across the contiguous US, leaving only about 5 percent as an inventoried roadless area or wilderness. Now, some of those last remaining lands free of roads are under threat from the Trump administrati

Most of what we know about the Earth's interior comes from observing seismic waves. These travel at somewhat different speeds depending on the details of the rock they're moving through—whether it's solid or semi-molten, how much water is present, whether it's fractured or solid material, and so on. Get enough data from enough seismic events, and you can start piecing together a picture of what's present at different depths below the surface. In many cases, we can get this data from naturally oc

Elon Musk’s talk about maintaining a million-strong AI data center satellite megaconstellation may not exactly be practical or economical, but it might be unique. It’s about the closest we’ve come to confronting a scheme that would export a considerable amount of valuable materials into space. Humans aren’t doing a great job of material sustainability, but normally we’re talking about stuff escaping a recycling pipeline rather than escaping Earth’s gravitational pull. The commercial space sector

Sgr A* is the name we've given to the supermassive black hole that sits at the center of the Milky Way. We've known about its presence since the 1970s but only managed to image it within the past few years. In the intervening time, most of our understanding of the object was obtained by watching a group of stars that orbit the black hole, helping us get a good estimate of its mass and size. In essence, those stars acted as instruments that let us peer into an environment we couldn't study any ot

SpaceX's most recent Starship test flight may have ended July 24, but its mission isn't over yet. The spacecraft splashed down in the Indian Ocean intact after flying halfway around the world from SpaceX's launch base in South Texas. Engineers expected the ship's life to end with a fiery disintegration after toppling over, just as past Starships have done following splashdown. Numerous onboard sensors and cameras, along with buoys and drones in position at the splashdown zone, have provided impo

CT scan of a narwhal tusk. Credit: Adrian Rodriguez Palomo/CC BY-NC CT scan of a narwhal tusk. Credit: Adrian Rodriguez Palomo/CC BY-NC Narwhals are toothed whales, renowned for their distinctive straight, spiraling tusks, which many people in medieval times believed were the horns of unicorns and thus held magical healing properties. That belief was debunked long ago, but the tusks remain popular souvenirs in Canada and Greenland

Solar storms, like the one in August 1972 that hit during the gap between the Apollo 16 and Apollo 17 missions, throw bursts of protons intense enough to raise an astronaut's cancer risk or even cause radiation sickness. Earth's atmosphere and magnetic field absorb this radiation, but crews heading to the Moon or Mars won't have that protection, and no spacecraft built so far has enough shielding to stop it. A team led by Jordan Houri and Oren Milstein of StemRad, an Israeli-American startup dev

Physicists with the Beijing Spectrometer III (BES III) experiment have uncovered convincing new evidence of the existence of so-called glueballs, an elusive composite particle made entirely of gluons predicted by quantum theory. The results appeared in a preprint posted to arXiv last month and were also presented last week at the International Conference on High Energy Physics (ICHEP). All the stuff we see around us is made up of quarks held together by gluons (carriers of the nuclear strong for

The Cambrian explosion may have been fueled by poop. The first animals on Earth emerged about 600 million years ago, and 60 million years later, those simple early animals evolved in wildly different directions, branching out into a diverse menagerie of complicated new forms and conquering new ecological niches. Known as the Cambrian Explosion, this flurry of rapid evolution produced most of the animal phyla and ecosystems we see around us today. And it may have taken off because some of those e

Global warming is leading to more extremely hot weather. There is perhaps no more obvious consequence of climate change. But changing how we analyze this problem can still help scientists think about it in a different way that may yield surprises. Generally, studies on heat extremes work with some combination of daily minimum, maximum, and mean temperatures. Sometimes they focus on multi-day heatwaves using those metrics, since the discomfort and health impacts increase for longer events. There

In October 2025, a storm brewed over the Caribbean Sea. Weather models differed on its trajectory. Would it remain weak and end up in Haiti, or would it intensify and head to Jamaica? Artificial intelligence model WeatherNext, developed by Google’s DeepMind and Google Research, went with the latter. Five days before landfall, it predicted with 80 percent confidence that the storm system would hit Jamaica as a Category 5 hurricane. Hurricane Melissa was catastrophic, causing flooding and landslid

A walk down the tarmac at the National Air and Space Museum of France is guaranteed to thrill aviation enthusiasts. Several civilian and military aircraft of the past and the present are showcased in this museum, located at the Paris-Le Bourget airport. One of them is the legendary Concorde F-WTSS 001 prototype, the sight of which should give goosebumps to science enthusiasts as well. That’s because right behind its long nose is a painted map that traces the path of a June 1973 total solar eclip

Snails are well-known for their mucus. The slime is highly valued as an anti-inflammatory and anti-aging ingredient in certain skin care products, and snails can secrete different kinds of mucus with properties tailored to specific functions. A team of German scientists has determined a recipe for how snails achieve that so-called tunability: Collagen and calcium work in tandem to achieve the varying mechanical properties, according to a new paper in the journal Science. Snail mucus is mostly wa

Wherever two fluids slide past each other at different speeds, the boundary between them buckles, then curls, then rolls up into vortexes. It’s called the Kelvin-Helmholtz instability, and the physics behind it was worked out in the late 1860s. We know this instability explains why wind causes ripples on the surface of water and clouds shear into a row of curves. For decades scientists argued the same thing must be happening with plasma on the surface of the Sun, and yet nobody had been able to

On Thursday, a US District Court in Oregon ordered the US government to restart the process of approving wind projects. All new wind development in the US has been on hold since August 2025, when the Department of Defense (DoD) stopped participating in a process that allows it to compel developers to alter projects in order to limit their interference with radar equipment. The court ruled, however, that the DoD's national security claims did not allow it to opt out of a process that is legally m

A lot of the AI work in biology has been focused on designing proteins. That's partly because proteins do most of the business of life, catalyzing the interesting chemistry and structuring cells. So, figuring out how to make a new protein can mean directly tinkering with biochemistry, providing new and potentially useful functions. Since the genetic code provides a layer of abstraction between DNA and proteins, it wasn't obvious what a model trained on DNA could do. Yet people went ahead and mad

The parasitic fungi in the Cordyceps genus are a favorite subject of nature documentaries. They've also infiltrated popular culture via the zombie-apocalypse video game The Last of Us (2013) and its TV adaptation, in which a parasitic fungus mutates to infect humans. Scientists are keen to study Cordyceps to learn more about the origins and intricate mechanisms underlying these pathogen-based diseases. The latest finding: DNA analysis revealed the same fungus in both parasitized insects and surr

The city of Houston, where I live, has been ground zero for the 2026 Atlantic hurricane season. So far this year there have been two named storms, Arthur and Bertha, that have formed. And the centers of both have passed near or directly over Houston. Two "strikes" in a year might seem notable, but like the middling hurricane season to date, Arthur and Bertha were both middle-of-the road tropical storms in terms of intensity. As a resident of a coastal region prone to hurricanes, one never wants

D-Wave is a bit of an oddity in the quantum computing space, having been founded back in the last century. And its initial offering wasn't a quantum computer like those being developed by IBM or Google. Instead, the company built what's now called a quantum annealer, a machine that isn't general-purpose but can solve a large class of optimization problems. While the hardware shares some similarities with the qubits used in gate-based quantum computers, it operates in a fundamentally different wa