China's first Student (Youth) Games concluded on Wednesday in Nanning, South China's Guangxi Zhuang Autonomous Region. Drawing about 20,000 young players, the Games awarded 805 gold medals across various sports. 

The Games showcased outstanding athletic achievements and the deepening integration of sports and education in China. Young athletes from different regions and schools competed and interacted in a display of youthful vitality. 

The Games marked the merging and upgrading of the National Youth Games and the National Student Games, providing a high-level competitive platform for young sports talents in China. Notably, 11 world youth records were exceeded, one world record was tied, and three Asian records were bettered.

Among all the 69 delegations participating in the open group, 64 won medals, with 54 winning gold medals. Delegations from the Hong Kong and Macao Special Administrative Regions won gold medals in the equestrian events and swimming events, respectively.

Additionally, a number of national records, national youth records and national juvenile records were set in sports such as shooting, track and field and weightlifting. In the campus group, all 34 delegations won medals, with 30 winning gold.

The first gold medal of the Games was won in Beihai, Guangxi, where 19-year-old Huang Yaoshu from the Haikou team won the men's longboard surfing event, leading the runner-up by nearly five points. 

In less than half a year since he started surfing in July 2017, Huang was selected for the Provincial Surfing Team of Hainan, the southernmost island province of China. As a kid who grew up in a fishing village, he had a natural love for surfing, but he said that he was not a talented athlete and so had to train hard for a long time. He noted that mastering a new move gives him a sense of accomplishment.

In Mashan county of Guangxi, 14-year-old Li Yantan from Guling Town Junior High School, a rural school surrounded by cliffs and precipices, excelled in rock climbing. The girl from the Zhuang ethnic group improved her performance from 11.90 seconds in the preliminaries to 10.91 seconds in the finals, securing a gold medal. Her coach, Wu Guoyong, mentioned that Li had been training in rock climbing since primary school and had shown significant improvement over the past five years.

The Games serve as an important opportunity to showcase the development of youth sports in China and represent the latest attempt at integrating sports and education. This integration is crucial for the overall development and growth of young athletes in the country, sport commentator Luo Le told the Global Times.

Luo noted that the Games provide an excellent platform for selecting talents for China's competitive sports industry. It offers young athletes a rare opportunity to gain experience in major competitions, which is vital for their development and future success in sports.

Chinese star hurdler Wu Yanni, who won the women's 100-meter hurdles during the Games, hit back at online criticism after her win.

"Some people online were saying, 'Don't jump the gun again this time.' But I was thinking, even if I did, so what?" 

Wu was disqualified for a false start at the 19th Asian Games held in Hangzhou in October. She gained supports for her confidence and straightforwardness after her public push back at the Student (Youth) Games. 

The environment in which the current generation of young athletes is growing up is significantly different from that of earlier athletes. These athletes are maturing in an era dominated by new media, and they themselves are examples of how to spread the spirit and culture of sports to the wider youth community, experts said. 

"As representatives of the new generation and the future of China's sports industry, they play a pivotal role in guiding younger athletic talents. The channels through which they exert their influence and promote sports have evolved, reflecting the broader trends in societal development," said Luo.

"These athletes are not only embracing but also shaping the societal trends in sports, effectively communicating the values and culture of sports to the youth of today. The Games have also been a part of that chain," Luo said. 

NEW ORLEANS — In a primordial soup on ancient Earth, droplets of chemicals may have paved the way for the first cells. Shape-shifting droplets split, grow and split again in new computer simulations. The result indicates that simple chemical blobs can exhibit replication, one of the most basic properties of life, physicist Rabea Seyboldt of the Max Planck Institute for the Physics of Complex Systems in Dresden, Germany, reported March 16 at a meeting of the American Physical Society.

Within a liquid, small droplets of particular chemicals can separate out, like beads of oil in water. Such globules typically remain spherical, growing as they merge with other drops. But in simulations, Seyboldt and colleagues found that droplets might behave in a counterintuitive way under certain conditions, elongating and eventually dividing into two.
If additional droplet material is continuously produced in reactions in the primordial soup, chemicals will accumulate on either end of a droplet, causing it to elongate, the simulations show. Meanwhile, waste products from the droplet are eliminated from the middle, causing the droplet to pinch in and eventually split. The resulting pair of droplets would then grow and split again to create a new generation. In addition to the above reactions, the process requires an energy source, such as heat or chemicals from a hydrothermal vent, to get reactions going.

The study, which was also described in Nature Physics in December, is theoretical — the researchers didn’t select particular chemicals for study but simply showed that certain types of reactions could cause droplets to split.

How such droplets would have evolved into vastly more complicated cells is unknown. “This is really a minimal scenario that’s supposed to give the very first indications of something that goes towards life, but if you look at living cells today, they’re infinitely more complex,” Seyboldt said.

Some scientific anniversaries celebrate events so momentous that they capture the attention of many nonscientists as well — or even the entire world.

One such anniversary is upon us. December 2 marks the semisesquicentennial (75th anniversary) of the first controlled and sustained nuclear fission chain reaction. Only four years after German scientists discovered nuclear fission, scientists in America took the first step toward harnessing it. Many of those scientists were not Americans, though, but immigrants appalled by Hitler and horrified at the prospect that he might acquire a nuclear fission weapon.

Among the immigrants who initiated the American fission effort was Albert Einstein. His letter to President Franklin Roosevelt, composed at the request and with the aid of immigrant Leo Szilard from Hungary, warned of nuclear fission’s explosive potential. Presented with Einstein’s letter in October 1939, Roosevelt launched what soon became the Manhattan Project, which eventually produced the atomic bomb. It was another immigrant, Enrico Fermi from Italy, who led the initial efforts to show that building an atomic bomb was possible.

Fermi had arrived in the United States in January 1939, shortly after receiving the Nobel Prize in physics for his work on creating artificial elements heavier than uranium. Except that he hadn’t actually done so — his “new elements” were actually familiar elements produced by the splitting of the uranium nucleus. But nobody knew that fission was possible, so Fermi had misinterpreted his results. Chemists Otto Hahn and Fritz Strassmann, working in Germany, conducted experiments in 1938 that produced the element barium by bombarding uranium with neutrons. So Hahn and Strassmann got the credit for discovering fission, although they didn’t really know what they had done either. It was Lise Meitner, a former collaborator of Hahn’s who had recently left Germany to avoid Nazi anti-Semitism, who figured out that they had split the uranium nucleus.
Meitner’s nephew Otto Frisch revealed her insight to Niels Bohr, the world’s leading atomic physicist, just as he stepped aboard a ship for a visit to America. Upon arriving in the United States, Bohr informed Fermi and Princeton University physicist John Archibald Wheeler of Hahn’s experiment and Meitner’s explanation. Fermi immediately began further experimental work at Columbia University to investigate fission, as did Szilard, also at Columbia (and others in Europe); Bohr and Wheeler tackled the issue from the theoretical side.

Fermi and Szilard quickly succeeded in showing that a fission “chain reaction” was in principle possible: Neutrons emitted from fissioning uranium nuclei could induce more fission. By September, Bohr and Wheeler had produced a thorough theoretical analysis, explaining the physics underlying the fission process and identifying which isotope of uranium fissioned most readily. It was clear that the initial speculations about fission’s potential power had not been exaggerated.

“Almost immediately it occurred to many people around the world that this could be used to make power and that it could be used for nuclear explosives,” another immigrant who worked on the Manhattan Project, the German physicist Hans Bethe, told me during an interview in 1997. “Lots of people verified that indeed when uranium is bombarded by neutrons, slow neutrons in particular, a process occurs which releases tremendous amounts of energy.”
Bethe, working at Cornell University, did not immediately join the fission project — he thought building a bomb would take too long to matter for World War II. “I thought this had nothing to do with the war,” he said. “So I instead went into radar.”

Fermi, despite being an immigrant, was put in charge of constructing an “atomic pile” (nowadays nuclear reactor) to verify the chain reaction theory. He was, after all, widely acknowledged as the world’s leading nuclear experimentalist (and was no slouch as a theorist either); colleagues referred to him as “The Pope” because of his supposed infallibility. Construction of the pile began on a squash court under the stands of the University of Chicago’s football stadium. The goal was to demonstrate the ability to generate a chain reaction, in which any one fissioning nucleus would emit enough neutrons to trigger even more nuclei to fission.

“It became clear to Fermi almost immediately that in order to do this with natural uranium you had to slow down the neutrons,” Bethe said.

Fermi decided that the best material for slowing neutrons was graphite, the form of carbon commonly used as pencil lead. But in preliminary tests the graphite did not do the job as Fermi had anticipated. He reasoned that the graphite contained too many impurities to work effectively. So Szilard began searching for a company that could produce ultrapure graphite. He found one, Bethe recalled, that happily agreed to meet Fermi’s purity requirements — for double the usual graphite price.
Ultimately Fermi’s atomic pile succeeded, producing a sustained chain reaction on December 2, 1942. That success led to the establishment of the secret laboratory in Los Alamos, N.M., where physicists built the bombs that brought World War II to an end in 1945.

By then, Bethe had been persuaded to join the project. He arrived at Los Alamos in April 1943 and witnessed the first nuclear explosion, at Alamogordo, N.M., on July 16, 1945.

“I was among the people who looked at it from a 20-mile distance,” he said. “It was impressive.”

Historians frequently cite the report of J. Robert Oppenheimer, director of the Los Alamos project, who said that the explosion reminded him of a line from the Hindu Bhagavad Gita: “Now I am become Death, the destroyer of worlds.”

Bethe recalled a different response, from one of the military officials on the scene.

“One of the officers at the explosion said, ‘My god. Those longhairs have let it get away from them.’”

Honeybees and bumblebees have a way to resist toxic compounds in some widely used insecticides.

These bees make enzymes that help the insects break down a type of neonicotinoid called thiacloprid, scientists report March 22 in Current Biology. Neonicotinoids have been linked to negative effects on bee health, such as difficulty reproducing in honeybees (SN: 7/26/16, p 16). But bees respond to different types of the insecticides in various ways. This finding could help scientists design versions of neonicotinoids that are less harmful to bees, the researchers say.
Such work could have broad ramifications, says study coauthor Chris Bass, an applied entomologist at the University of Exeter in England. “Bees are hugely important to the pollination of crops and wild flowers and biodiversity in general.”

Neonicotinoids are typically coated on seeds such as corn and sometimes sprayed on crops to protect the plants from insect pests. The chemicals are effective, but their use has been suspected to be involved in worrisome declines in numbers of wild pollinators (SN Online: 4/5/12).

Maj Rundlöf of Lund University in Sweden helped raise the alarm about the insecticides. In 2015, she reported that neonicotinoid-treated crops reduced the populations of bees that fed from the plants. Rundlöf, who was not involved with the new study, says the new research is important because it clarifies differences between the insecticides. “All neonicotinoids are not the same,” she says. “It’s a bit unrealistic to damn a whole group of pesticides.”

Bass and his colleagues, which include scientists from Bayer, one of the main producers of neonicotinoids, investigated resistance to thiacloprid by looking at bees’ defense systems. The team focused on enzymes known as P450s, which can metabolize toxic chemicals, breaking them down before they affect the bee nervous system. The researchers used drugs to inhibit groups of P450 enzymes. When the family enzymes called CYP9Q was inhibited, bees became 170 times as sensitive to thiacloprid, dying from a much smaller dose, the researchers found. Discovering the enzymes’ protective power could lead to more effective ways to simultaneously avoid harming bees and help crops.
“We live in an era that uses pesticides,” Rundlöf says. “We need to figure out the ones that are safest.”

An ancient four-legged whale walked across land on hooved toes and swam in the sea like an otter.

The newly discovered species turned up in 2011 in a cache of fossilized bones in Playa Media Luna, a dry coastal area of Peru. Jawbones and teeth pegged it as an ancient cetacean, a member of the whale family. And more bones followed.

“We were definitely surprised to find this type of whale in these layers, but the best surprise was its degree of completeness,” says Olivier Lambert, a paleontologist at the Royal Belgian Institute of Natural Sciences in Brussels.
Jaw, tooth and spine features, described April 4 in Current Biology, don’t quite match anything else in the fossil record, setting the skeleton apart as a new species, dubbed Peregocetus pacificus (meaning “the traveling whale that reached the Pacific Ocean”). At 42.6 million years old, it’s the oldest whale skeleton found in the New World, though some fossilized whale teeth from North America may be even older.

Big, possibly webbed feet and long toes would have allowed P. pacificus to dog-paddle or swim freestyle. And like modern otters and beavers, this whale’s vertebrae suggest that its tail also functioned as a paddle. With tiny hooves and strong legs and hips, the animal could walk on land. But “it was definitely a better swimmer than walker,” Lambert says.

Whales got their start on land and gradually adapted to a water-dwelling lifestyle. The first amphibious whales emerged more than 50 million years ago near what’s now India and Pakistan. The new species shares some similar features with Maiacetus and Rodhocetus, two early whales from that area. P. pacificus’ age supports the idea that whales migrated across the South Atlantic and around South America to the Pacific Ocean in their first 10 million years of existence.

A nebulous void in Egypt’s Great Pyramid of Giza has been unveiled thanks to strange subatomic particles called muons.

Scientists first identified the void in 2016 using muons, heavy relatives of electrons that can penetrate through solid materials. Thought to be a corridor-shaped hole, the void was located near a chevron-shaped structure visible on the pyramid’s north face. Further muon measurements revealed new details of the void’s size and shape, scientists from the ScanPyramids team report March 2 in Nature Communications.
The new muon measurements indicate that the void is a 9-meter-long corridor about 2 meters wide by 2 meters tall, close to the pyramid’s north face. ScanPyramids researchers made additional measurements with ground-penetrating radar and ultrasonic testing, they reported March 2 in NDT & E International. The detailed measurements allowed the scientists to use an endoscope to take images inside the chamber, the team announced. The images reveal a corridor with a vaulted ceiling, presumably one that was hasn’t been seen by humans since the pyramid was built more than 4,500 years ago. The corridor’s purpose is still unclear.
Muons are created when high-energy particles from space called cosmic rays crash into the Earth’s atmosphere. Muons are partially absorbed as they rain down onto structures such as the pyramids. Using detectors placed inside the pyramid, scientists from ScanPyramids zeroed in on regions where more muons made it through, indicating they’d traversed less material, which let them map out the location of the void.

Scientists also recently used muons to probe an ancient Chinese wall (SN: 1/30/23), a nuclear reactor and various volcanoes (SN: 4/22/22).

Artificial intelligence has passed the last major milestone in mastering poker: six-player no-limit Texas Hold’em.

Games like poker, with hidden cards and players who bluff, present a greater challenge to AI than games where every player can see the whole board. Over the last few years, computers have become aces at increasingly complicated forms of one-on-one poker, but multiplayer games take that complexity to the next level (SN Online: 5/13/15).

Now, a card shark AI dubbed Pluribus has outplayed more than a dozen elite professionals at six-player Texas Hold’em, researchers report online July 11 in Science. Algorithms that can plot against several adversaries using such spotty information could make savvy business negotiators, political strategists or cybersecurity watchdogs.
Pluribus honed its initial strategy by playing against copies of itself, starting from scratch and gradually learning which actions helped to win. Then, the AI used that intuition for when to hold and when to fold during the first betting round of each hand against five human players.

During subsequent betting rounds, Pluribus fine-tuned its strategy by imagining how the game might play out if it took different actions. Unlike artificial intelligence trained for two-player poker, Pluribus didn’t speculate all the way to the end of the game — which would require too many computations when dealing with so many players (SN: 4/1/17, p. 12). Instead, the AI imagined several moves ahead and decided what to do based on those hypothetical futures and different strategies that players could adopt.

In 10,000 hands of Texas Hold’em, Pluribus competed against five contestants from a pool of 13 professionals, all of whom had won more than $1 million playing poker. Every 100 hands, Pluribus raked in, on average, about $480 from its human competitors.
“This is roughly the amount that elite human professionals aspire to beat weaker players by,” implying that Pluribus was a savvier player than its human opponents, says Noam Brown of Facebook AI Research in New York City. Brown, along with Tuomas Sandholm of Carnegie Mellon University in Pittsburgh, created Pluribus.

Now that AI has poker in the bag, algorithms could test their strategic reasoning in games with more complex hidden information, says computer scientist Viliam Lisý of the Czech Technical University in Prague, who was not involved in the work. In games like Kriegspiel — a chess spin-off where players can’t see each other’s pieces — the unknowns can become far more complicated than a few cards held close to opponents’ chests, Lisý says.

Video games like StarCraft, which allow many more types of moves and free players from rigid, turn-based play, could also serve as new tests of AI cleverness (SN: 5/11/19, p. 34).

Homo sapiens who reached Europe around 54,000 years ago introduced bows and arrows to that continent, a new study suggests.

Researchers examined tiny triangular stone points and other artifacts excavated at a rock-shelter in southern France called Grotte Mandrin. H. sapiens on the move probably brought archery techniques from Africa to Europe, archaeologist Laure Metz of Aix-Marseille University in France and colleagues report February 22 in Science Advances.

“Metz and colleagues demonstrate bow hunting [at Grotte Mandrin] as convincingly as possible without being caught bow-in-hand,” says archaeologist Marlize Lombard of the University of Johannesburg, who did not participate in the new study.
No bows were found at the site. Wooden items such as bows preserve poorly. The oldest intact bows, found in northern European bogs, date to around 11,000 years ago, Metz says.

Previous stone and bone point discoveries suggest that bow-and-arrow hunting originated in Africa between about 80,000 and 60,000 years ago. And previously recovered fossil teeth indicate that H. sapiens visited Grotte Mandrin as early as 56,800 years ago, well before Neandertals’ demise around 40,000 years ago and much earlier than researchers had thought that H. sapiens first reached Europe (SN: 2/9/22).

“We’ve shown that the earliest known Homo sapiens to migrate into Neandertal territories had mastered the use of the bow,” Metz says.

No evidence suggests that Neandertals already present in Europe at that time launched arrows at prey. It’s also unclear whether archery provided any substantial hunting advantages to H. sapiens relative to spears that were thrust or thrown by Neandertals.
Among 852 stone artifacts excavated in a H. sapiens sediment layer at Grotte Mandrin dated to about 54,000 years ago, 196 triangular stone points displayed high-impact damage. Another 15 stone points showed signs of both high-impact damage and alterations caused by butchery activities, such as cutting.

Comparisons of those finds were made to damage on stone replicas of the artifacts that the researchers used as arrowheads shot from bows and as the tips of spears inserted in handheld throwing devices. Additional comparative evidence came from stone and bone arrowheads used by recent and present-day hunting groups.

Impact damage along the edges of stone points from the French site indicated that these implements had been attached at the bottom to shafts.

The smallest Grotte Mandrin points, many with a maximum width of no more than 10 millimeters, could have pierced animals’ hides only when shot from bows as the business ends of arrows, the researchers say. Experiments they conducted with replicas of the ancient stone points found that stone points less than 10 millimeters wide reach effective hunting speeds only when attached to arrow shafts propelled by a bow.

Larger stone points, some of them several times the size of the smaller points, could have been arrowheads or might have tipped spears that were thrown or thrust by hand or launched from handheld spear throwers, the researchers conclude.

Lombard, the University of Johannesburg archaeologist, suspects that the first H. sapiens at the French rock-shelter hunted with bows and arrows as well as with spears, depending on where and what they were hunting. Earlier studies directed by Lombard indicated that sub-Saharan Africans similarly alternated between these two types of hunting weapons starting between about 70,000 and 58,000 years ago.

H. sapiens newcomers to Europe may have learned from Neandertals that spear hunting in large groups takes precedence on frigid landscapes, where bow strings can easily snap and long-distance pursuit of prey is not energy efficient, Lombard says.

But learning about archery from H. sapiens may not have been in the cards for Neandertals. Based on prior analyses of brain impressions on the inside surfaces of fossil skulls, Lombard suspects that Neandertals’ brains did not enable the enhanced visual and spatial abilities that H. sapiens exploited to hunt with bows and arrows.

That’s a possibility, though other controversial evidence suggests that Neandertals behaved no differently from Stone Age H. sapiens (SN: 3/26/20).If Grotte Mandrin Neandertals never hunted with bows and arrows but still survived just fine alongside H. sapiens archers for roughly 14,000 years, reasons for Neandertals’ ultimate demise remain as mysterious as ever.

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.”