Whether it’s Katy Perry poaching dancers from once-BFF Taylor Swift or Clytemnestra orchestrating the murder of her husband Agamemnon, betrayal is a dark, persistent part of the human condition. Unlike garden-variety deception, betrayal happens in established relationships, destroying trust that has developed over time. It’s usually unexpected, and it yields a unique, often irreparable, wound. In fact, betrayers have a special place in hell, literarily: In Dante’s Inferno, they occupy the ninth and final circle; mere fraudsters dwell in the eighth.

While most of us are familiar with betrayal, investigating it is really hard. (Consider all the complications of a study that asks people in trusted relationships to betray each other.) Case studies of real betrayals can provide insight after-the-fact, but without a time machine, finding studies that reveal big picture patterns about the lead-up to treachery are scarce.

“We all know betrayal exists,” says Cristian Danescu-Niculescu-Mizil, a computer scientist at Cornell University who spends a lot of time thinking about what language reveals about relationships. “But finding relevant data is really hard.”

So when Danescu-Niculescu-Mizil heard about a Diplomacy, a strategy game rife with betrayal, he figured it might serve as a good proxy for real life treachery. And he was right: Studying the patterns of communication between the players revealed that betrayal is sometimes foreseeable. But like many relationships that collapse in betrayal, teasing out what goes wrong and who is at fault isn’t so easy.
Unlike Risk and other war games, Diplomacy is all about, well, diplomacy (John F. Kennedy and Henry Kissinger reportedly were fans). Set in Europe before World War I, the nations/players have to form alliances to win. But chance is removed from the equation; players don’t roll dice or take turns. There’s only diplomacy: a negotiation phase where players converse, form alliances and gather intelligence (these days, typically online), and a movement phase where everyone’s decisions are revealed and executed all at once. Betrayal is so integral to Diplomacy that, as noted on a “This American Life” episode, stabbing an ally in the back is referred to by the shorthand “stabbing.”

Danescu-Niculescu-Mizil, colleague and fan-of-the-game Jordan Boyd-Graber, and colleagues examined 249 games of Diplomacy with a total of 145,000 messages among players. When they used a computer program to compare exchanges between players whose relationships ended in betrayal with those whose relationships lasted, the computer discerned subtle signals of impending betrayal.

One harbinger was a shift in politeness. Players who were excessively polite in general were more likely to betray, and people who were suddenly more polite were more likely to become victims of betrayal, study coauthor and Cornell graduate student Vlad Niculae reportedJuly 29 at the Annual Meeting of the Association for Computational Linguistics in Beijing. Consider this exchange from one round:

Germany: Can I suggest you move your armies east and then I will support you? Then next year you move [there] and dismantle Turkey. I will deal with England and France, you take out Italy.

Austria: Sounds like a perfect plan! Happy to follow through. And—thank you Bruder!

Austria’s next move was invading German territory. Bam! Betrayal.

An increase planning-related language by the soon-to-be victim also indicated impending betrayal, a signal that emerges a few rounds before the treachery ensues. And correspondence of soon-to-be betrayers had an uptick in positive sentiment in the lead-up to their breach.
Working from these linguistic cues, a computer program could peg future betrayal 57 percent of the time. That might not sound like much, but it was better than the accuracy of the human players, who never saw it coming. And remember that by definition, a betrayer conceals the intention to betray; the breach is unexpected (that whole trust thing). Given that inherent deceit, 57 percent isn’t so bad.

When I spoke to Danescu-Niculescu-Mizil, he said that more important than the clues themselves is the shift in the balance of behavior in the relationship. Positive or negative sentiment of one player isn’t what matters, it’s the asymmetry of the behavior of the two people in the relationship. He likens the linguistic tells to body language: While you wouldn’t use it as a sole basis for decision-making, if you know how to interpret it, it might give you an advantage.

More work is needed to explore whether these patterns exist in real life. And while the research did reveal some patterns, it can’t say anything about cause and effect or who is at fault. Perhaps, for example, the extensive planning of the eventual victims came off as super bossy and frustrating to the eventual betrayer. After all, Clytemnestra’s betrayal of Agamemnon came after he killed their daughter Iphigenia. That kind of bad blood may be unforgivable.

Particles of twisted light that have been entangled using quantum mechanics offer a new approach to dense and secure data storage.

Holograms that produce 3-D images and serve as security features on credit cards are usually made with patterns laid down with beams of laser light. In recent years, physicists have found ways to create holograms with entangled photons instead. Now there is, literally, a new twist to the technology.

Entangled photons that travel in corkscrew paths have resulted in holograms that offer the possibility of dense and ultrasecure data encryption, researchers report in a study to appear in Physical Review Letters.
Light can move in a variety of ways, including the up-and-down and side-to-side patterns of polarized light. But when it carries a type of rotation known as orbital angular momentum, it can also propagate in spirals that resemble twisted rotini pasta.

Like any other photons, the twisted versions can be entangled so that they essentially act as one entity. Something that affects one of an entangled photon pair instantly affects the other, even if they are very far apart.

In previous experiments, researchers have sent data through the air in entangled pairs of twisted photons (SN: 8/5/15). The approach should allow high-speed data transmission because light can come with different amounts of twist, with each twist serving as a different channel of communication.

Now the same approach has been applied to record data in holograms. Instead of transmitting information on multiple, twisted light channels, photon pairs with different amounts of twist create distinct sets of data in a single hologram. The more orbital angular momentum states involved, each with different amounts of twist, the more data researchers can pack into a hologram.

In addition to cramming more data into holograms, increasing the variety of twists used to record the data boosts security. Anyone who wants to read the information out needs to know, or guess, how the light that recorded it was twisted.

For a hologram relying on two types of twist, says physicist Xiangdong Zhang of the Beijing Institute of Technology, you would have to pick the right combination of the twists from about 80 possibilities to decode the data. Bumping that up to combinations of seven distinct twists leads to millions of possibilities. That, Zhang says, “should be enough to ensure our quantum holographic encryption system has enough security level.”
The researchers demonstrated their technique by encoding words and letters in holograms and reading the data back out again with twisted light. Although the researchers produced images from the holographic data, says physicist Hugo Defienne of the Paris Institute of Nanosciences, the storage itself should not be confused with holographic images.

Defienne, who was not involved with the new research, says that other quantum holography schemes, such as his efforts with polarized photons, produce direct images of objects including microscopic structures.

“[Their] idea there is very different . . . from our approach in this sense,” Defrienne says. “They’re using holography to store information,” rather than creating the familiar 3-D images that most people associate with holograms.

The twisted light data storage that Zhang and his colleagues demonstrated is slow, requiring nearly 20 minutes to decode an image of the acronym “BIT,” for the Beijing Institute of Technology where the experiments were performed. And the security that the researchers have demonstrated is still relatively low because they included only up to six forms of twisted light in their experiments.

Zhang is confident that both limitations can be overcome with technical improvements. “We think that our technology has potential application in quantum information encryption,” he says, “especially quantum image encryption.”

The existing boundaries of national parks and other habitat preserves aren’t enough to protect more than three-quarters of the world’s well-studied insects.

The finding, reported February 1 in One Earth, shows that people who design nature preserves “don’t really think about insects that much,” says coauthor Shawan Chowdhury, an ecologist at the German Centre for Integrative Biodiversity Research in Leipzig.

That’s a problem because insect populations around the globe are plummeting, a growing body of research suggests, probably due to climate change and human development (SN: 4/26/22). For instance, insect abundance in Puerto Rico has dropped by up to 98 percent over the last 35 years.
Threats to insect survival could have ripple effects on plants and other animals. Insects help form the foundation for many ecosystems: They pollinate around 80 percent of all plant species and serve as a staple in the diets of hundreds of thousands of animals (and the occasional carnivorous plant).

One way to avert insect extinctions is to set aside the land they need to survive. But scientists know the ranges for only about 100,000 of the estimated 5.5 million insect species. To determine how well existing protected areas may be aiding insect conservation, Chowdhury and colleagues mapped the known habitats of about 89,000 of those species and compared the ranges with the boundaries of preserves from the World Database on Protected Areas.

Overall, these spaces don’t safeguard enough habitat for 67,384 insect species — about 76 percent of the species included in the study — the team found. Roughly 2 percent of species do not overlap with protected areas at all.

Conserving insects, Chowdhury says, will mean setting aside more insect-friendly spaces in the years ahead.

Our planet may have had a recent change of heart.

Earth’s inner core may have temporarily stopped rotating relative to the mantle and surface, researchers report in the January 23 Nature Geoscience. Now, the direction of the inner core’s rotation may be reversing — part of what could be a roughly 70-year-long cycle that may influence the length of Earth’s days and its magnetic field — though some researchers are skeptical.

“We see strong evidence that the inner core has been rotating faster than the surface, [but] by around 2009 it nearly stopped,” says geophysicist Xiaodong Song of Peking University in Beijing. “Now it is gradually mov[ing] in the opposite direction.”
Such a profound turnaround might sound bizarre, but Earth is volatile (SN: 1/13/21). Bore through the ever-shifting crust and you’ll enter the titanic mantle, where behemoth masses of rock flow viscously over spans of millions of years, sometimes upwelling to excoriate the overlying crust (SN: 1/11/17, SN: 3/2/17, SN: 2/4/21). Delve deeper and you’ll reach Earth’s liquid outer core. Here, circulating currents of molten metals conjure our planet’s magnetic field (SN: 9/4/15). And at the heart of that melt, you’ll find a revolving, solid metal ball about 70 percent as wide as the moon.

This is the inner core (SN: 1/28/19). Studies have suggested that this solid heart may rotate within the liquid outer core, compelled by the outer core’s magnetic torque. Researchers have also argued the mantle’s immense gravitational pull may apply an erratic brake on the inner core’s rotation, causing it to oscillate.

Evidence for the inner core’s fluctuating rotation first emerged in 1996. Geophysicist Paul Richards of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y., and Song, then also at Lamont-Doherty, reported that over a span of three decades, seismic waves from earthquakes took different amounts of time to traverse Earth’s solid heart.

The researchers inferred that the inner core rotates at a different speed than the mantle and crust, causing the time differences. The planet spins roughly 360 degrees in a day. Based on their calculations, the researchers estimated that the inner core, on average, rotates about 1 degree per year faster than the rest of Earth.

But other researchers have questioned that conclusion, some suggesting that the core spins slower than Song and Richards’ estimate or doesn’t spin differently at all.

In the new study, while analyzing global seismic data stretching back to the 1990s, Song and geophysicist Yi Yang — also at Peking University — made a surprising observation.
Before 2009, seismic waves generated by sequences and pairs of repeating earthquakes — known as multiplets and doublets — traveled at different rates through the inner core. This indicated the waves from recurring quakes were crossing different parts of the inner core, and that the inner core was rotating at a different pace than the rest of Earth, aligning with Song’s previous research.

But around 2009, the differences in travel times vanished. That suggested the inner core had ceased rotating with respect to the mantle and crust, Yang says. After 2009, these differences returned, but the researchers inferred that the waves were crossing parts of the inner core that suggested it was now rotating in the opposite direction relative to the rest of Earth.

The researchers then pored over records of Alaskan earthquake doublets dating to 1964. While the inner core appeared to rotate steadily for most of that time, it seems to have made another reversal in rotation in the early 1970s, the researchers say.

Song and Yang infer that the inner core may oscillate with a roughly 70-year periodicity — switching directions every 35 years or so. Because the inner core is gravitationally linked to the mantle and magnetically linked to the outer core, the researchers say these oscillations could explain known 60- to 70-year variations in the length of Earth’s days and the behavior of the planet’s magnetic field. However, more work is needed to pin down what mechanisms might be responsible.

But not all researchers are on board. Yang and Song “identif[y] this recent 10-year period [that] has less activity than before, and I think that’s probably reliable,” says geophysicist John Vidale of the University of Southern California in Los Angeles, who was not involved in the research. But beyond that, Vidale says, things get contentious.

In 2022, he and a colleague reported that seismic waves from nuclear tests show the inner core may reverse its rotation every three years or so. Meanwhile, other researchers have proposed that the inner core isn’t moving at all. Instead, they say, changes to the shape of the inner core’s surface could explain the differences in wave travel times.

Future observations will probably help disentangle the discrepancies between these studies, Vidale says. For now, he’s unruffled by the purported chthonic standstill. “In all likelihood, it’s irrelevant to life on the surface, but we don’t actually know what’s happening,” he says. “It’s incumbent on us to figure it out.”

MONTREAL — For the first time, scientists have precisely captured a map of the boisterous bang radiating from a lightning strike. The work could reveal the energies involved in powering some of nature’s flashiest light shows.

As electric current rapidly flows from a negatively charged cloud to the ground below, the lightning rapidly heats and expands the surrounding air, generating sonic shock waves. While scientists have a basic understanding of thunder’s origins, they lack a detailed picture of the physics powering the crashes and rumbles.
Heliophysicist Maher Dayeh of the Southwest Research Institute in San Antonio and colleagues sparked their own lightning by firing a long, Kevlar-coated copper wire into an electrically charged cloud using a small rocket. The resulting lightning followed the conductive wire to the ground. Using 15 sensitive microphones laid out 95 meters from the strike zone, Dayeh said he and his colleagues precisely recorded the incoming sound waves. Because sound waves from higher elevations took longer to reach the microphones, the scientists could create an acoustic map of the lightning strike with “surprising detail,” Dayeh said. He presented the results May 5 at a meeting of the American Geophysical Union and other organizations.

The loudness of a thunderclap depends on the peak electric current flowing through the lightning, the researchers found. This discovery could one day allow scientists to use thunder to sound out the amount of energy powering a lightning strike, Dayeh said.
SHOCK AND AWE Scientists shot a long copper wire into a lightning-prone cloud using a small rocket. The generated lightning followed the wire down to the ground, allowing the researchers to record the sound waves of the resulting thunder. The green flashes are caused by the intense heating of the copper wire. Credit: Univ. of Florida, Florida Institute of Technology, SRI

A flexible electronic implant could one day make pain management a lot more chill.

Created from materials that dissolve in the body, the device encircles nerves with an evaporative cooler. Implanted in rats, the cooler blocked pain signals from zipping up to the brain, bioengineer John Rogers and colleagues report in the July 1 Science.

Though far from ready for human use, a future version could potentially let “patients dial up or down the pain relief they need at any given moment,” says Rogers, of Northwestern University in Evanston, Ill.
Scientists already knew that low temperatures can numb nerves in the body. Think of frozen fingers in the winter, Rogers says. But mimicking this phenomenon with an electronic implant isn’t easy. Nerves are fragile, so scientists need something that gently hugs the tissues. And an ideal implant would be absorbed by the body, so doctors wouldn’t have to remove it.

Made from water-soluble materials, the team’s device features a soft cuff that wraps around a nerve like toilet paper on a roll. Tiny channels snake down its rubbery length. When liquid coolant that’s pumped through the channels evaporates, the process draws heat from the underlying nerve. A temperature sensor helps scientists hit the sweet spot — cold enough to block pain but not too cold to damage the nerve.

The researchers wrapped the implant around a nerve in rats and tested how they responded to having a paw poked. With the nerve cooler switched on, scientists could apply about seven times as much pressure as usual before the animals pulled their paws away. That’s a sign that the rats’ senses had grown sluggish, Rogers says.

He envisions the device being used to treat pain after surgery, rather than chronic pain. The cooler connects to an outside power source and would be tethered to patients like an IV line. They could control the level of pain relief by adjusting the coolant’s flow rate. Such a system might offer targeted relief without the downsides of addictive pain medications like opioids, Rogers suggests (SN: 8/27/19).

Now the researchers want to explore how long they can apply the cooling effect without damaging tissues, Rogers says. In experiments, the longest that they cooled rats’ nerves was for about 15 minutes.

“If treating pain, cooling would have to go on for a much longer period of time,” says Seward Rutkove, a nerve physiologist at Harvard Medical School who wasn’t involved in the study. Still, he adds, the device is “an interesting proof of concept and should definitely be pursued.”