“I was talking with my colleagues at a conference 10 years ago and I just casually said that everyone loves music,” recalls Josep Marco Pallarés, a neuroscientist at the University of Barcelona. But it was a statement he started to question almost immediately, given there were clinical cases in psychiatry where patients reported deriving absolutely no pleasure from listening to any kind of tunes.

So, Pallarés and his team spent the past 10 years researching the neural mechanisms behind a condition they called specific musical anhedonia: the inability to enjoy music.

The wiring behind joy

When we like something, it is usually a joint effect of circuits in our brain responsible for perception—be it perception of taste, touch, or sound—and reward circuits that give us a shot of dopamine in response to nice things we experience. For a long time, scientists attributed a lack of pleasure from things most people find enjoyable to malfunctions in one or more of those circuits.

You can’t enjoy music when the parts of the brain that process auditory stimuli don’t work properly, since you can’t hear it in the way that you would if the system were intact. You also can’t enjoy music when the reward circuit refuses to release that dopamine, even if you can hear it loud and clear. Pallarés, though, thought this traditional idea lacked a bit of explanatory power.

“When your reward circuit doesn’t work, you don’t experience enjoyment from anything, not just music,” Pallarés says. “But some people have no hearing impairments and can enjoy everything else—winning money, for example. The only thing they can’t enjoy is music.”

https://arstechnica.com/science/2025/08/for-some-people-music-doesnt-connect-with-any-of-the-brains-reward-circuits/

Understanding the wakes and vortices that jellyfish produce as they swim is crucial, according to Wu, et al. Particle image velocimetry (PIV) is a vital tool for studying flow phenomena and biomechanical propulsion. PIV essentially tracks tiny tracer particles suspended in water by illuminating them with laser light. The technique usually relies on hollow glass spheres, polystyrene beads, aluminum flakes, or synthetic granules with special optical coatings to enhance the reflection of light.

These particles are readily available and have the right size and density for flow measurements, but they are very expensive, costing as much as $200 per pound in some cases. And they have associated health and environmental risks: glass microspheres can cause skin or eye irritation, for example, while it’s not a good idea to inhale polystyrene beads or aluminum flakes. They are also not digestible by animals and can cause internal damage. Several biodegradable options have been proposed, such as yeast cells, milk, micro algae, and potato starch, which are readily available and cheap, costing as little as $2 per pound.

Wu thought starch particles were the most promising as biodegradable tracers and decided to study several different kinds of starches to identify the best candidate: specifically, corn starch, arrowroot starch, baking powder, jojoba beads, and walnut shell powder. Each type of particle was suspended in water tanks with moon jellyfish, tracking their movement with a PIV system. They evaluated their performance based on the particles’ size, density, and laser-scattering properties.

Of the various candidates, corn starch and arrowroot starch proved best suited for PIV applications, thanks to their density and uniform size distribution, while arrowroot starch performed best when it came to laser scattering tests. But corn starch would be well-suited for applications that require larger tracer particles since it produced larger laser scattering dots in the experiments. Both candidates matched the performance of commonly used synthetic PIV tracer particles in terms of accurately visualizing flow structures resulting from the swimming jellyfish.

DOI: Physical Review Fluids, 2025. 10.1103/bg66-976x  (About DOIs).

https://arstechnica.com/science/2025/08/scientists-are-building-cyborg-jellyfish-to-explore-ocean-depths/

The dissents

The primary dissent was written by Chief Justice Roberts, and joined in part by the three Democratic appointees, Jackson, Kagan, and Sotomayor. It is a grand total of one paragraph and can be distilled down to a single sentence: “If the District Court had jurisdiction to vacate the directives, it also had jurisdiction to vacate the ‘Resulting Grant Terminations.’”

Jackson, however, chose to write a separate and far more detailed argument against the decision, mostly focusing on the fact that it’s not simply a matter of abstract law; it has real-world consequences.

She notes that existing law prevents plaintiffs from suing in the Court of Federal Claims while the facts are under dispute in other courts (something acknowledged by Barrett). That would mean that, as here, any plaintiffs would have to have the policy declared illegal first in the District Court, and only after that was fully resolved could they turn to the Federal Claims Court to try to restore their grants. That’s a process that could take years. In the meantime, the scientists would be out of funding, with dire consequences.

Yearslong studies will lose validity. Animal subjects will be euthanized. Life-saving medication trials will be abandoned. Countless researchers will lose their jobs. And community health clinics will close.

Jackson also had little interest in hearing that the government would be harmed by paying out the grants in the meantime. “For the Government, the incremental expenditure of money is at stake,” she wrote. “For the plaintiffs and the public, scientific progress itself hangs in the balance along with the lives that progress saves.”

With this decision, of course, it no longer hangs in the balance. There’s a possibility that the District Court’s ruling that the government’s policy was arbitrary and capricious will ultimately prevail; it’s not clear, because Barrett says she hasn’t even seen the government make arguments there, and Roberts only wrote regarding the venue issues. In the meantime, even with the policy stayed, it’s unlikely that anyone will focus grant proposals on the disfavored subjects, given that the policy might be reinstated at any moment.

And even if that ruling is upheld, it will likely take years to get there, and only then could a separate case be started to restore the funding. Any labs that had been using those grants will have long since moved on, and the people working on those projects scattered.

https://arstechnica.com/science/2025/08/deeply-divided-supreme-court-lets-nih-grant-terminations-continue/

A local Neolithic community in northeastern France may have clashed with foreign invaders, cutting off limbs as war trophies and otherwise brutalizing their prisoners of war, according to a new paper published in the journal Science Advances. The findings challenge conventional interpretations of prehistoric violence as bring indiscriminate or committed for pragmatic reasons.

Neolithic Europe was no stranger to collective violence of many forms, such as the odd execution and massacres of small communities, as well as armed conflicts. For instance, we recently reported on an analysis of human remains from 11 individuals recovered from El Mirador Cave in Spain, showing evidence of cannibalism—likely the result of a violent episode between competing Late Neolithic herding communities about 5,700 years ago. Microscopy analysis revealed telltale slice marks, scrape marks, and chop marks, as well as evidence of cremation, peeling, fractures, and human tooth marks.

This indicates the victims were skinned, the flesh removed, the bodies disarticulated, and then cooked and eaten. Isotope analysis indicated the individuals were local and were probably eaten over the course of just a few days. There have been similar Neolithic massacres in Germany and Spain, but the El Mirador remains provide evidence of a rare systematic consumption of victims.

Per the authors of this latest study, during the late Middle Neolithic, the Upper Rhine Valley was the likely site of both armed conflict and rapid cultural upheaval, as groups from the Paris Basin infiltrated the region between 4295 and 4165 BCE. In addition to fortifications and evidence of large aggregated settlements, many skeletal remains from this period show signs of violence.

Friends or foes?

Archaeologist Teresa Fernandez-Crespo of Spain’s Valladolid University and co-authors focused their analysis on human remains excavated from two circular pits at the Achenheim and Bergheim sites in Alsace in northwestern France. Fernandez-Crespo et al. examined the bones and found that many of the remains showed signs of unhealed trauma—such as skull fractures—as well as the use of excessive violence (overkill), not to mention quite a few severed left upper limbs. Other skeletons did not show signs of trauma and appeared to have been given a traditional burial.

https://arstechnica.com/science/2025/08/neolithic-people-took-gruesome-trophies-from-invading-tribes/

Insects are more influential than we realize

By showing that ant- and termite-based diets evolved repeatedly, the study highlights the overlooked role of social insects in shaping biodiversity. “This work gives us the first real roadmap, and what really stands out is just how powerful a selective force ants and termites have been over the last 50 million years, shaping environments and literally changing the face of entire species,” Barden said.

However, according to the study authors, we still do not have a clear picture of how much of an impact insects have had on the history of life on our planet. Lots of lineages have been reshaped by organisms with outsize biomass—and today, ants and termites have a combined biomass exceeding that of all living wild mammals, giving them a massive evolutionary influence.

However, there’s also a flip side. Eight of the 12 myrmecophagous origins are represented by just a single species, meaning most of these lineages could be vulnerable if their insect food sources decline. As Barden put it, “In some ways, specializing in ants and termites paints a species into a corner. But as long as social insects dominate the world’s biomass, these mammals may have an edge, especially as climate change seems to favor species with massive colonies, like fire ants and other invasive social insects.”

For now, the study authors plan to keep exploring how ants, termites, and other social insects have shaped life over millions of years, not through controlled lab experiments, but by continuing to use nature itself as the ultimate evolutionary archive. “Finding accurate dietary information for obscure mammals can be tedious, but each piece of data adds to our understanding of how these extraordinary diets came to be,” Vida argued.

Evolution, 2025. DOI: 10.1093/evolut/qpaf121 (About DOIs)

Rupendra Brahambhatt is an experienced journalist and filmmaker. He covers science and culture news, and for the last five years, he has been actively working with some of the most innovative news agencies, magazines, and media brands operating in different parts of the globe.

https://arstechnica.com/science/2025/08/mammals-that-chose-ants-and-termites-as-food-almost-never-go-back/

Chinese media reports suggest the Guowang satellites could accommodate a range of instrumentation, including broadband communications payloads, laser communications terminals, synthetic aperture radars, and optical remote sensing payloads. This sounds a lot like a mix of SpaceX and the NRO’s Starshield fleet, the Space Development Agency’s future constellation, and the proposed MILNET program.

In testimony before a Senate committee in June, the top general in the US Space Force said it is “worrisome” that China is moving in this direction. Gen. Chance Saltzman, the Chief of Space Operations, used China’s emergence as an argument for developing space weapons, euphemistically called “counter-space capabilities.”

“The space-enabled targeting that they’ve been able to achieve from space has increased the range and accuracy of their weapon systems to the point where getting anywhere close enough [to China] in the Western Pacific to be able to achieve military objectives is in jeopardy if we can’t deny, disrupt, degrade that… capability,” Saltzman said. “That’s the most pressing challenge, and that means the Space Force needs the space control counter-space capabilities in order to deny that kill web.”

The US military’s push to migrate many wartime responsibilities to space is not without controversy. The Trump administration wants to cancel purchases of new E-7 jets designed to serve as nerve centers in the sky, where Air Force operators receive signals about what’s happening in the air, on the ground, and in the water for hundreds of miles around. Instead, much of this responsibility would be transferred to satellites.

Some retired military officials, along with some lawmakers, argue against canceling the E-7. They say there’s too little confidence in when satellites will be ready to take over. If the Air Force goes ahead with the plan to cancel the E-7, the service intends to bridge the gap by extending the life of a fleet of Cold War-era E-3 Sentry airplanes, commonly known as AWACS (Airborne Warning and Control System).

But the high ground of space offers notable benefits. First, a proliferated network of satellites has global reach, and airplanes don’t. Second, satellites could do the job on their own, with some help from artificial intelligence and edge computing. This would remove humans from the line of fire. And finally, using a large number of satellites is inherently beneficial because it means an attack on one or several satellites won’t degrade US military capabilities.

https://arstechnica.com/space/2025/08/china-may-have-taken-an-early-lead-in-the-race-for-a-military-megaconstellation/

In the end, the chihuahua recovered nicely, and the vets advised the owners to fit him out with a basket muzzle when he was not being actively monitored, to protect the dog from its impulse to eat bad things. The case is interesting in part because of the dog’s low heart rate in response to the cocaine; the drug typically causes the heart rate to race much faster than normal. “The net cardiovascular effect of cocaine in canines remains complex,” the authors concluded, calling for further research into the long-term effects on the cardiovascular system for dogs accidentally ingesting the drug.

Per Johnson, there are several common-sense preventive measures dog owners can take to protect their pets. For instance, keep your dog on a leash during walks and monitor anything the animal happens to pick up and/or consume. Training dogs to respond promptly to commands like “leave it!” or “drop it!” are also valuable and could potentially save an animal’s life. And if your dog does happens to ingest cocaine or similar substances despite these efforts, take them to the vet immediately and be completely honest about the circumstances—yes, even if the drugs were yours.

“A major misconception in toxicology research, particularly with illicit substances, is that veterinarians will judge owners or report them to authorities if they admit their pet may have ingested drugs,” said Johnson. “This fear prevents crucial information sharing that could save lives. Being honest about potential exposure can be lifesaving. The more information you can provide about what, when, and how much your pet may have consumed, the better we can tailor treatment and monitor for specific complications. What matters most is getting your pet immediate help, not assigning blame.”

DOI: Frontiers in Veterinary Science, 2025. 10.3389/fvets.2025.1622850  (About DOIs).

https://arstechnica.com/science/2025/08/the-case-of-the-coke-snorting-chihauhua/

Erin’s central pressure was in the 990s this time yesterday, and it’s now in the 920’s heading for the teens.

This will make Erin the fastest deepening Atlantic hurricane before Sept 1st. Beating Emily 2005, by a lot.

[image or embed]

— Sam Lillo (@samlillo.bsky.social) August 16, 2025 at 9:29 AM

With a central pressure of 917 mb on Saturday, Erin ranks as the second-most intense Atlantic in the last 50 years prior to today’s date, behind only Hurricane Allen in 1980.

Rapid intensification becoming more common

Storms like Erin are predicted to become more common due to climate change, scientists say. One study in 2019 found that, for the strongest 5 percent of Atlantic hurricanes, 24-hour intensification rates increased by about 3–4 mph per decade from 1982 to 2009. “Our results suggest a detectable increase of Atlantic intensification rates with a positive contribution from anthropogenic forcing,” the authors of the study, in Nature Communications, wrote.

Hurricane scientists generally agree that although the overall number of tropical storms and hurricanes may not increase in a warmer world, such background conditions are likely to produce more intense storms like Erin.

According to the US government’s Climate.gov website, this increase in intensity of tropical cyclones (TCs) is happening due to human-caused climate change.

“The proportion of severe TCs (Category 4 & 5) has increased, possibly due to anthropogenic climate change,” a coalition of authors wrote. “This proportion of intense TCs is projected to increase further, bringing a greater proportion of storms having more damaging wind speeds, higher storm surges, and more extreme rainfall rates. Most climate model studies project a corresponding reduction in the proportion of low-intensity cyclones, so the total number of TCs each year is projected to decrease or remain approximately the same.”

To date this year the tropical Atlantic has seen lower overall activity than usual. But with Erin’s longevity and intensity this season should soon reach and surpass normal levels of Accumulated Cyclone Energy, a measurement of a season’s total activity. The Atlantic season typically peaks in early September, with the majority of storms forming between early August and early October.

Forecast models indicate the likely development of more hurricanes within the next two weeks, but there is no clear consensus on whether they will impact land.

https://arstechnica.com/science/2025/08/hurricane-erin-sets-early-season-intensification-record-becomes-category-5-storm/

It’s even possible that neutrinos can act as their own antiparticles—that is, that neutrinos could turn into antineutrinos and vice versa. This scenario, which the discovery of right-handed neutrinos would support, would make neutrinos fundamentally different from more familiar particles like quarks and electrons. If antineutrinos can turn into neutrinos, that could help explain where the antimatter went during the universe’s earliest moments.

One way to test this idea is to look for an unusual type of radioactive decay — theorized but thus far never observed—known as “neutrinoless double-beta decay.” In regular double-beta decay, two neutrons in a nucleus simultaneously decay into protons, releasing two electrons and two antineutrinos in the process. But if neutrinos can act as their own antiparticles, then the two neutrinos could annihilate each other, leaving only the two electrons and a burst of energy.

A number of experiments are underway or planned to look for this decay process, including the KamLAND-Zen experiment, at the Kamioka neutrino detection facility in Japan; the nEXO experiment at the SNOLAB facility in Ontario, Canada; the NEXT experiment at the Canfranc Underground Laboratory in Spain; and the LEGEND experiment at the Gran Sasso laboratory in Italy. KamLAND-Zen, NEXT, and LEGEND are already up and running.

While these experiments differ in the details, they all employ the same general strategy: They use a giant vat of dense, radioactive material with arrays of detectors that look for the emission of unusually energetic electrons. (The electrons’ expected neutrino companions would be missing, with the energy they would have had instead carried by the electrons.)

While the neutrino remains one of the most mysterious of the known particles, it is slowly but steadily giving up its secrets. As it does so, it may crack the puzzle of our matter-dominated universe — a universe that happens to allow inquisitive creatures like us to flourish. The neutrinos that zip silently through your body every second are gradually revealing the universe in a new light.

“I think we’re entering a very exciting era,” says Turner.

This article originally appeared in Knowable Magazine, a nonprofit publication dedicated to making scientific knowledge accessible to all. Sign up for Knowable Magazine’s newsletter.

https://arstechnica.com/science/2025/08/how-a-mysterious-particle-could-explain-the-universes-missing-antimatter/

Engineers recreated the diffuser failure on the ground during the investigation, and then redesigned the part to better direct pressurized gas into the main fuel tank. This will also “substantially decrease” strain on the diffuser structure, SpaceX said.

The FAA, charged with ensuring commercial rocket launches don’t endanger public safety, signed off on the investigation and gave the green light for SpaceX to fly Starship again when it is ready.

“SpaceX can now proceed with Starship Flight 10 launch operations under its current license,” the FAA said.

“The upcoming flight will continue to expand the operating envelope on the Super Heavy booster, with multiple landing burn tests planned,” SpaceX said in an update posted to its website Friday. “It will also target similar objectives as previous missions, including Starship’s first payload deployment and multiple reentry experiments geared towards returning the upper stage to the launch site for catch.”

In the aftermath of the test flight in May, SpaceX hoped to fly Starship again by late June or early July. But another accident June 18, this time on the ground, delayed the program another couple of months. The Starship vehicle SpaceX assigned to the next flight, designated Ship 36, exploded on a test stand in Texas as teams filled it with cryogenic propellants for an engine test-firing.

The accident destroyed the ship and damaged the test site, prompting SpaceX to retrofit the sole active Starship launch pad to support testing of the next ship in line—Ship 37. Those tests included a brief firing of all six of the ship’s Raptor engines August 1.

After Ship 37’s final spin prime test Wednesday, workers transported the rocket back to a hangar for evaluation, and crews immediately got to work transitioning the launch pad back to its normal configuration to host a full Super Heavy/Starship stack.

SpaceX said the explosion on the test stand in June was likely caused by damage to a high-pressure nitrogen storage tank inside Starship’s payload bay section. This tank, called a composite overwrapped pressure vessel, or COPV, violently ruptured and led to the ship’s fiery demise. SpaceX said COPVs on upcoming flights will operate at lower pressures, and managers ordered additional inspections on COPVs to look for damage, more proof testing, more stringent acceptance criteria, and a hardware change to address the problem.

https://arstechnica.com/space/2025/08/spacex-reveals-why-the-last-two-starships-failed-as-another-launch-draws-near/