research roundup

It’s a regrettable reality that there is never enough time to cover all the interesting scientific stories we come across each month. In the past, we’ve featured year-end roundups of cool science stories we (almost) missed. This year, we’re experimenting with a monthly collection. June’s list includes the final results from the Muon g-2 experiment, re-creating the recipe for Egyptian blue, embedding coded messages in ice bubbles, and why cats seem to have a marked preference for sleeping on their left sides.

Re-creating Egyptian blues

Artists in ancient Egypt were particularly fond of the color known as Egyptian blue—deemed the world’s oldest synthetic pigment—since it was a cheap substitute for pricier materials like lapis lazuli or turquoise. But archaeologists have puzzled over exactly how it was made, particularly given the wide range of hues, from deep blue to gray or green. That knowledge had long been forgotten. However, scientists at Washington State University have finally succeeded in recreating the recipe, according to a paper published in the journal npj Heritage Science.

The interdisciplinary team came up with 12 different potential recipes using varying percentages of silicon dioxide, copper, calcium, and sodium carbonate. They heated the samples to 1,000° Celsius (about what ancient artists could have achieved), varying the time between one and 11 hours. They also cooled the samples at different rates. Then they analyzed the samples using microscopy and other modern techniques and compared them to the Egyptian blue on actual Egyptian artifacts to find the best match.

Their samples are now on display at the Carnegie Museum of Natural History in Pittsburgh. Apart from its historical interest, Egyptian blue also has fascinating optical, magnetic, and biological properties that could prove useful in practical applications today, per the authors. For instance, it might be used for counterfeit-proof inks, since it emits light in the near-infrared, and its chemistry is similar to high-temperature superconductors.

npj Heritage Science, 2025. DOI: 10.1038/s40494-025-01699-7  (About DOIs).

World’s smallest violin

It’s an old joke, possibly dating back to the 1970s. Whenever someone is complaining about an issue that seems trivial in the grand scheme of things, it’s tradition to rub one’s thumb and forefinger together and declare, “This the world’s smallest violin playing just for you.” (In my snarky circles we used to say the violin was “playing ‘My Heart Bleeds for You.'”) Physicists at Loughborough University have now made what they claim really is the world’s smallest violin, just 35 microns long and 13 microns wide.

There are various lithographic methods for creating patterned electronic devices, such as photolithography, which can be used either with a mask or without. The authors relied on scanning probe thermal lithography instead, specifically a cutting-edge nano-sculpting machine they dubbed the NanoFrazor. The first step was to coat a small chip with two layers of a gel material and then place it under the NanoFrazor. The instrument’s heated tip burned the violin pattern into the gel. Then they “developed” the gel by dissolving the underlayer so that only a violin-shaped cavity remained.

Next, they poured on a thin layer of platinum and rinsed off the chip with acetone. The resulting violin is a microscopic image rather than a playable tiny instrument—you can’t even see it without a microscope—but it’s still an impressive achievement that demonstrates the capabilities of the lab’s new nano lithography system. And the whole process can take as little as three hours.

Muon g-2 anomaly no more?

The Muon g-2 experiment (pronounced “gee minus two”) is designed to look for tantalizing hints of physics beyond the Standard Model of particle physics. It does this by measuring the magnetic field (aka the magnetic moment) generated by a subatomic particle known as the muon. Back in 2001, an earlier run of the experiment at Brookhaven National Laboratory found a slight discrepancy, hinting at possible new physics, but that controversial result fell short of the critical threshold required to claim discovery.

Physicists have been making new measurements ever since in hopes of resolving this anomaly. For instance, in 2021, we reported on data from the updated Muon g-2 experiment that showed “excellent agreement” with the discrepancy Brookhaven recorded. They improved on their measurement precision in 2023. And now it seems the anomaly is very close to being resolved, according to a preprint posted to the physics arXiv based on analysis of a data set triple the size as the one used for the 2023 analysis. (You can watch a video explanation here.)

The final Muon g-2 result is in agreement with the 2021 and 2023 results, but much more precise, with error bars four times smaller than those of the original Brookhaven experiment. Combine that with new predictions by the related Muon g-2 Theory Initiative using a new means of calculating the muon’s magnetic moment, and the discrepancy between theoretical prediction and experiment narrows even further.

While some have declared victory, and the Muon g-2 experiment is completed, theorists are still sounding a note of caution as they seek to further refine their models. Meanwhile, Fermilab is building a new experiment designed to hunt for muon-to-electron conversions. If they find any, that would definitely comprise new physics beyond the Standard Model.

arXiv, 2025. DOI: 10.48550/arXiv.2506.03069 (About DOIs).

Message in a bubble

Forget sending messages in a bottle. Scientists have figured out how to encode messages in both binary and Morse code in air bubbles trapped in ice, according to a paper published in the journal Cell Physical Science. Trapped air bubbles are usually shaped like eggs or needles, and the authors discovered that they could manipulate the sizes, shapes, and distribution of those ice bubbles by varying the freezing rate. (Faster rates produce egg-shaped bubbles, slower rates produce needle-shaped ones, for example.)

To encode messages, the researchers assigned different bubble sizes, shapes, and orientations to Morse code and binary characters and used their freezing method to produce ice bubbles representing the desired characters. Next, they took a photograph of the ice layer and converted it to gray scale, training a computer to identify the position and the size of the bubbles and decode the message into English letters and Arabic numerals. The team found that binary coding could store messages 10 times longer than Morse code.

Someday, this freezing method could be used for short message storage in Antarctica and similar very cold regions where traditional information storage methods are difficult and/or too costly, per the authors. However, Qiang Tang of the University of Australia, who was not involved in the research, told New Scientist that he did not see much practical application for the breakthrough in cryptography or security, “unless a polar bear may want to tell someone something.”

Cell Physical Science, 2025. DOI: 10.1016/j.xcrp.2025.102622 (About DOIs).

Cats prefer to sleep on left side

The Internet was made for cats, especially YouTube, which features millions of videos of varying quality, documenting the crazy antics of our furry feline friends. Those videos can also serve the interests of science, as evidenced by the international team of researchers who analyzed 408 publicly available videos of sleeping cats to study whether the kitties showed any preference for sleeping on their right or left sides. According to a paper published in the journal Current Biology, two-thirds of those videos showed cats sleeping on their left sides.

Why should this behavioral asymmetry be the case? There are likely various reasons, but the authors hypothesize that it has something to do with kitty perception and their vulnerability to predators while asleep (usually between 12 to 16 hours a day). The right hemisphere of the brain dominates in spatial attention, while the right amygdala is dominant for processing threats. That’s why most species react more quickly when a predator approaches from the left. Because a cat’s left visual field is processed in the dominant right hemisphere of their brains, “sleeping on the left side can therefore be a survival strategy,” the authors concluded.

Current Biology, 2025. DOI: 10.1016/j.cub.2025.04.043 (About DOIs).

A mobile ultrasonic brain imaging helmet

Brain imaging is a powerful tool for both medical diagnosis and neuroscience research, from noninvasive methods like EEGs, MRI,  fMRI, and diffuse optical tomography, to more invasive techniques like intracranial EEG. But the dream is to be able to capture the human brain functioning in real-world scenarios instead of in the lab. Dutch scientists are one step closer to achieving that goal with a specially designed 3D-printed helmet that relies upon functional ultrasound imaging (fUSi) to enable high-quality 2D imaging, according to a paper published in the journal Science Advances.

Unlike fMRI, which requires subjects to remain stationary, the helmet monitors the brain as subjects are walking and talking (accompanied by a custom mobile fUSi acquisition cart). The team recruited two 30-something male subjects who had undergone cranioplasty to embed an implant made of polyetheretherketone (PEEK). While wearing the helmet, the subjects were asked to perform stationary motor and sensory tasks: pouting or brushing their lips, for example. Then the subjects walked in a straight line, pushing the cart for a minute up to 30 meters while licking their lips to demonstrate multitasking. The sessions ran over a 20-month period, thereby demonstrating that the helmet is suitable for long-term use. The next step is to improve the technology to enable mobile 3D imaging of the brain.

Science Advances, 2025. DOI: 10.1126/sciadv.adu9133  (About DOIs).

It’s a regrettable reality that there is never time to cover all the interesting scientific stories we come across each month. In the past, we’ve featured year-end roundups of cool science stories we (almost) missed. This year, we’re experimenting with a monthly collection of such stories. March’s list includes fascinating papers on such topics as how the brain responds to speaking Klingon (or Dothraki, or Navi), the discovery of creepy preclassic Salvadoran puppets, the effectiveness of “dazzle camouflage,” and how male blue-lined octopuses manage not to be cannibalized by their chosen mates.

Wind Cave’s rocks fluoresce under black light

South Dakota’s Wind Cave gets its name from the flow of air moving continually through its many passages and equalizing the atmospheric pressure between the air inside and outside—almost like the cave is “breathing.” Its rock and mineral formations also boast a unique chemistry that fluoresces when exposed to black light, according to talks presented at the spring meeting of the American Chemical Society in San Diego. That fluorescence could shed light on how life can thrive in extreme environments, including that of Jupiter’s moon, Europa.

University of Northern Iowa astrobiologist Joshua Sebree and several students have been mapping new areas of Wind Cave (as well as other caves in the US), recording the passages, rock formations, minerals, and lifeforms they encounter in the process. They noticed that under UV light, certain parts of Wind Cave took on otherworldly hues, thanks to different concentrations of organic and inorganic fossilized chemical compounds. Those areas seem to indicate where water once flowed, carrying minerals into the cave from the surface 10,000 to 20,000 years ago, according to their analysis of the fluorescent spectra. Sebree et al. found that Wind Cave was likely carved out by waters rich in manganese, producing zebra stripes that glow pink under UV light, revealing the calcites that grew within as a result of those waters.

The physics of swing-top beer bottles

So-called kitchen science is all the rage these days, with champagne, wine, and beer being particularly favorite subjects for experimentation. German physicist Max Koch of the University of Goettingen is as passionate about home brewing as he is about fluid dynamics. So naturally, Koch became fascinated by the distinctive “pop and slosh” sounds produced whenever he opened one of his home-brewed swing-top beer bottles. His experiments used a high-speed camera to capture the acoustics and underlying physics, augmented by audio recording and computer simulations.

Rather than producing a single shockwave, Koch and his co-authors discovered that the unique sound occurs because popping the lid produces a vibrating standing wave, thanks to condensation within the bottleneck, according to a paper published in the journal Physics of Fluids. They were surprised to find that the frequency of the pop was significantly lower than the resonance produced by blowing across the open bottle top, which they attributed to the sudden expansion of the carbon dioxide and a strong cooling effect that reduces sound speed. The sloshing is due to the bottle’s motion, and it’s possible that the lid hitting the glass after popping could produce more bubbles and hence gushing.

Physics of Fluids, 2025. DOI: 10.1063/5.0248739  (About DOIs).

How effective was WWI “dazzle paint”?

During World War I, ships were often painted with complex geometric shapes in contrasting and intersecting colors, dubbed “dazzle camouflage” and usually attributed to British marine artist Norman Wilkinson. The objective was to confuse enemy U-boat captains trying to determine the speed and direction of those ships, and a 1919 study seemed to support that hypothesis. Aston University researchers have revisited that original study and concluded that the horizon effect—in which ships viewed from a distance seem to be traveling along the horizon—is a more effective means of confusing enemy combatants, according to a paper published in the journal i-Perception.

The author of the 1919 study was an MIT marine engineering student named Leo Blodgett, who painted model ships in those geometric patterns and observed them with a model periscope in a mechanical test theater to see if he could determine whether an observer’s perception of the direction of travel was markedly different from the actual direction. He concluded that this was indeed the case and therefore dazzle paint was effective.

But according to the Aston scientists, Blodgett’s experiment did not have a solid control condition to warrant such a conclusion. So they revisited his 105-year-old data and ran their own version of Blodgett’s experiment, comparing results from his photographs showing the original dazzle camouflage with versions that had the camouflage patterns edited out. The results: the dazzle camouflage did work via a twist on perspective, but it was a small effect. The horizon effect had a much stronger confounding effect.

i-Perception, 2025. DOI: 10.1177/20416695241312316  (About DOIs).

Early Salvadoran clay puppets

Archaeologists excavating the San Isidro pyramid in El Salvador have discovered five carved clay figurines dating back to around 400 BCE that may have been controlled with string like modern marionettes. Such “Bolinas” figures have also been found at a Mayan burial site in Guatemala, suggesting the two areas may have shared culture and civilization, according to a paper published in the journal Antiquity.

Three of the puppets were about a foot tall, with the other two measuring about 18 centimeters. The larger ones had adjustable heads connected to their bodies via matching sockets. The carved faces feature tongues, tattoos, and facial expressions that shift depending on the viewing angle: fearful when viewed from below and grinning from above, for example. The authors suggest that these puppets weren’t used as toys, but as “clay actors” in ritualistic funeral performances. “The universal impetus for creating scaled-down humanoid figures appears to be mimetic—that is, imbuing these handheld objects with deeper meanings that are readily decoded by the intended audience,” they concluded, although the shared cultural “code” for interpreting those meanings has been lost.

Antiquity, 2025. DOI: 10.15184/aqy.2025.37  (About DOIs).

This is your brain on Esperanto and Klingon

J.R.R. Tolkien invented two Elvish languages (Quenya and Sindarin) when writing The Lord of the Rings trilogy. Star Trek has Klingon, the Avatar films have Na’vi, and Game of Thrones boasts two constructed languages, or conlangs: Dothraki and High Valyrian. There are even hardcore fans who have diligently become proficient in those invented languages. And apparently conlangs activate the same parts of the brain as their native tongues, according to a paper published in the Proceedings of the National Academy of Sciences.

MIT neuroscientist Evelina Fedorenko previously spearheaded studies on how the brain responds to stimuli that share certain language features—music, gestures, facial expressions, and computer programming languages like Python. None seemed to engage the language-processing areas of the brain. Curious about what makes natural language unique, Fedorenko et al. turned to conlangs. They organized a weekend conference featuring conlang creators as speakers and invited people fluent in Esperanto, Klingon, Na’vi, Dothraki, and High Valyrian to participate. They scanned 44 conlang speakers with fMRI as they listened to sentences in both their chosen conlang and their native tongue, performing nonlinguistic tasks as a control.

The results: The same language regions lit up regardless of whether they were speaking in their chosen conlang or native natural language. This helped the group determine that language responses appear to be driven in part by how they convey meaning about the interior and exterior world—objects, properties of objects, events, etc. Python, by contrast, is highly symbolic and abstract, disconnected from the everyday “real” world we experience. The group next plans to study how the brain responds to a different conlang called Lojban, created in the 1990s, to learn more about which language features activate the brain’s language centers.

PNAS, 2025. DOI: 10.1073/pnas.2313473122  (About DOIs).

Venom as a protective strategy for male octopuses

Sexual cannibalism—in which a female of the species consumes the male after copulating—is a very real thing in nature, seen in insect species like mantises and spiders, certain crustaceans and gastropods, and even certain species of octopus. Case in point: the blue-lined octopus (Hapalochlaena fasciata), a tiny creature found in shallow waters whose venom can be quite deadly, especially to humans. The females of the species might be the size of golf balls, but they are nonetheless significantly larger than the males and have a tendency to eat their mates.

Fortunately, the males have developed an effective defense strategy, according to a paper published in the journal Current Biology: They inject their chosen females with tetrodotoxin (a venom also produced by pufferfish) just before mating, temporarily paralyzing the females so the males can avoid being eaten. Scientists at the University of Queensland studied the behavior of mating blue-lined octopuses in the lab and noticed that males would bite the females near the aorta as the mating ritual commenced, flooding their systems with the venom.

This immobilized the females for the duration of the mating sessions (which lasted between 40 and 75 minutes); they largely stopped breathing, turned pale, and did not respond to visual stimuli during that time. The males actually increased their respiration rate as they used a specialized mating arm to deposit their sperm into the females’ oviducts to fertilize the eggs. The effects of the venom eventually wore off sufficiently for the females to push the males away without suffering any permanent effects. The authors suggest that female blue-lined octopuses may have evolved a tolerance to tetrodotoxin, ensuring they survive to lay their eggs and propagate the species.

Current Biology, 2025. DOI: 10.1016/j.cub.2025.01.027  (About DOIs).

Rubber hand illusion alleviates pain

One of the many strange things to come out of 21st-century neuroscience is the so-called rubber hand illusion, in which a subject’s hand is hidden and replaced by a rubber hand in the position where the real hand would be. When both the real and fake hands are stroked simultaneously, subjects respond as if the rubber hand were part of their body. Threaten the rubber hand by attempting to stab it with a dagger, for instance, and the participants exhibit an involuntary startle or fear response. It’s the combination of visual and tactile feedback that does it, and it only takes a few seconds for the illusion to kick in. And it’s not a purely psychological effect; there have been measurable physiological responses as well.

Scientists in Bochum, Germany, have now shown that the rubber hand illusion can also alleviate pain, according to a paper published in the journal Pain Reports. They recruited 34 right-handed subjects, evaluated their individual pain thresholds, then placed the subjects’ left hands behind a screen. A left rubber hand was placed in front of the subjects, which could be lit from below with red light. Then heat was applied at different temperatures to the hidden hand, while red light increased on the visible rubber hand. Subjects were asked to rate their pain in response.

The results: subjects’ perception of pain decreased noticeably when the rubber hand illusion was used, compared to control conditions. The authors don’t yet know what the underlying mechanism might be but suggest it could be related to visual analgesia, in which pain is considered less intense if someone can see the part of the body that is being hurt.

Pain Reports, 2025. DOI: 10.1097/PR9.0000000000001252  (About DOIs).