Editor's Note:

Chinese people believe that letters are as valuable as gold. For thousands of years, letters, across mountains and oceans, have been delivering the writers' sentiments and conveying friendship and expectations.

Xi Jinping, general secretary of the Communist Party of China (CPC) Central Committee and Chinese president, has managed to find time to reply to some of the letters sent to him from different sectors of the society and different parts of the world despite of his busy work schedule.

Through his letters, Xi has corresponded with people from all walks of life on numerous occasions, part of a series of excellent China stories in the new era.

The Global Times traced and contacted some of the recipients of Xi's letters, to hear the inspiring stories behind the letters and their communications with the Chinese president.

In this installment, the Global Times speaks with teachers and students from Muscatine High School in Iowa, the US, who shared their experiences and insights from their visit to China for exchanges after being invited by President Xi, as well as their hopes for future youth exchanges between China and the US.

"I'm extremely thankful that President Xi spent time to write to us. It was very touching he was able to hear about the amazing times on our trip," Seinna Stonking, a freshman at Muscatine High School in the central US state of Iowa, told the Global Times.

This spring, Stoneking felt inspired and fruitful. She, together with more than 20 other students from her school, received a special gift - a letter from Chinese President Xi Jinping after they concluded their visit to China, which they considered as a "life-changing" and "eye-opening" journey.

On February 24, which marked the Chinese Lantern Festival of the Year of the Dragon, Xi replied to a letter from the students of Muscatine High School who visited China in late January and sent them New Year cards in return.

In the letter, the Chinese president encouraged the Muscatine High School students to revisit China and encouraged more American youths to come to China for exchanges and study, where they can get first-hand experience of a real China in a multi-dimensional and comprehensive manner, foster genuine friendship with the Chinese youth, and learn from each other so that they can jointly contribute to a stronger friendship between the people of the two countries.

Over the years, notwithstanding setbacks in China-US relations, Xi has consistently championed people-to-people exchanges with the US. He has written letters to Americans, stressing that the hope of the China-US relationship lies in the people, its foundation is in grass-roots connections, its future depends on the youth, and its vitality comes from subnational exchanges.

In tandem with the fervent hopes of the Chinese people, an increasing number of young Americans are immersing themselves in the vibrant tapestry of China. They're not merely visiting the nation, but also securing this chance to embrace the country's rich culture, and feel a profound connection between the two countries.

'Dear Grandpa Xi'

In an interview with the Global Times, students from Muscatine High School weren't bashful about their gratitude to President Xi.

"In my and my classmates' letter to President Xi, we wanted to highlight how eye-opening this trip truly was. To add on to this, how grateful we were to be able to have this once-in-a-lifetime opportunity," Stonking said.

With Xi's support, several Muscatine High School students paid an exchange visit to Beijing, Shanghai, and Hebei Province, among other places in China from January 24 to 30, becoming the first group of American students to visit China under a program Xi announced at Welcome Dinner by Friendly Organizations in the US, in San Francisco during his visit to the country in November 2023. The program aimed at inviting 50,000 American youths over the next five years to China for exchanges and study.

One of their gifts to Xi upon their arrival in Beijing was a school flag of Muscatine High School with the words "Grandpa Xi, Here We Are" written in Chinese.

Behind the phrase "Here We Are" was the excitement most students feel when coming to China for the first time, where they climb the Great Wall, visit the Forbidden City, and experience traditional Chinese culture such as writing Chinese calligraphy and weaving Chinese knots.

"It was a new experience for me; it was life-changing and I loved the Great Wall and Shanghai. I had a great time meeting all the teachers and students," Leo Regennitter, a sophomore at the school, told the Global Times.

"The most memorable experience for me will always be the opportunity I got to make a connection with many students I met. All the students and teachers were so unbelievably kind and hardworking. The many places I went to like the Great Wall or the Shanghai Tower took my breath away and were so beautiful," Stonking recalled.

On January 28, before the end of our visit to China, the children discussed what gifts they could give President Xi, to express their gratitude for inviting them to visit China and share with him the joy of their visit, Heidi Kuo, a Chinese language teacher at Muscatine High School, told the Global Times.

Then, a letter featuring beautifully written Chinese characters to "Dear Grandpa Xi" was born.

"Many students poured their heart into their letters, sketching the awe-inspiring highlights of their China journey. From the majestic Great Wall to the cuddly panda, each illustration breathed life into their experiences. There was also a vivid strokes of a hand-painted Chinese dragon in the letter that truly captured their belief in its symbolic representation of China," shared Kuo.

"China is really huge, just like the US. Thank you for giving us the opportunity to come to China," said the letter signed by over 20 students, with hearts drawn next to their signatures.

An 'eye-opening' trip
According to Muscatine Journal, on February 28, during their monthly work session, the Muscatine School Board had the opportunity to hear directly from some of the students and chaperones who visited China for a week, where both Regennitter and Stoneking had the chance to speak about some of their experiences.

Regennitter shared the wonderful experiences the group had at the Shijiazhuang Foreign Language School, which is Muscatine's sister school, where they played table tennis and learned to make Chinese knots. The group also had the opportunity to celebrate Chinese New Year at the Zhang Yuan Garden, where they were joined by college students from the US.

"I told so many people in my life it was an amazing experience that I'll never forget. If any student was thinking of going and was unsure, I would them to go for it and they won't regret it," Stoneking told the Global Times. "It's a completely different experience to see China in person," she emphasized.

While also citing the Chinese saying "seeing is believing" in his reply letter, Xi said the warm and friendly American people he met during his first visit to the US in 1985 have given him an indelible impression.

The same touching experience has happened after three decades, among a group of high school students.

"While in China, I've never felt safer and did not view the country as it can sometimes be portrayed in American media," Stoneking said.

Many US media outlets reported that the students' trip to China came amid increased tensions between the US and China in the wake of a series of fractious actions.

However, American students who come to China see that Chinese and American students have forged deep friendships and are eager to communicate with and learn about each other.

"From what I experienced, the people of the US and China are more similar than different and we can learn a lot from each other," Stonking stressed.

Stonking said she felt the trip to China was "so motivating," and encouraged her to learn more about the Chinese language and the culture, "If I get the opportunity I would love to go to college in China and I hope to be a fluent speaker (of Chinese) someday."

Friendship continues to flourish

Muscatine is honored to have sent the first batch of students in the youth exchange program. The encouragement of interactions between the young people of the two countries is a continuation of the nearly 40-year friendship between Xi and the people of Muscatine, American entrepreneur Gary Dvorchak told the Global Times.

In the spring of 1985, Xi, at that time a county leader in Zhengding, in China's northern province of Hebei, took his initial steps on US soil.

From then on, Xi never forgot his American friends and believes that people hold the key to state-to-state relations.

During his trip to the US in November 2023, Xi recalled the story of this friendship with his old friends, mentioning that the house number during his stay was No. 2911 Bonnie Drive.

Today, 2911 Bonnie Drive, just two kilometers from Muscatine High School, has a more familiar name among locals - Sino-US Friendship House.

Dvorchak, owner of the house, and son of Eleanor and Thomas Dvorchak, the family that hosted Xi during his 1985 visit to Muscatine, believed that President Xi's warm response to the school students shows the value he sees in having young people from both countries getting to know each other personally and better understanding the values we share as human beings.

Dvorchak believes that the 50,000 young people exchange program and the Sino-US Friendship House getting more attention shows that people-to-people exchanges are all signs of building positive momentum.

"My hopes are high that the level of interaction will grow, producing tighter bonds among the people of our two great countries. This effort is critical to improving the relations between our countries," he said.

Kuo, in her seventh year of teaching Chinese at Muscatine High School, has witnessed a remarkable shift in student interest toward China and its rich culture. From once being unfamiliar, more and more students now eagerly embrace the allure of China.

Excitingly, the school is gearing up to send more students on a trip to China this coming April.

"After returning from our trip and watching the videos we captured, many students expressed a strong desire to visit China," Kuo shared.

Some Chinese schools also expressed their interest in fostering a sister school relationship with Muscatine High School. "We are eager to see students from both countries build even stronger bonds of friendship," she said.

In ancient times, shells served as decorations, tools, religious artifacts and currency, as well as canvases for art. However, archaeological evidence of this practice has been scarce, and research in this area has been lacking.

Recently, Chinese scholars for the first time recreated images of shell paintings from over 2,000 years ago, based on findings at an archaeological site dating from the Warring States period (475BC-221BC). 

A paper authored by Professor Luo Wugan and a team from the University of Chinese Academy of Sciences and several other universities was recently published in the prestigious Journal of Cultural Heritage. It traces the history of shell paintings, a unique art form, back to at least the Warring States period in China.

Observations through three-dimensional video microscopy revealed that the production of the shell paintings began with precise delineation and positioning of images using raised lines. This technique is reminiscent of methods widely used in jade carving. The intricacy and precision of the craftsmanship on such small and fragile shells is highly impressive.

Subsequent comprehensive analysis using X-ray fluorescence and Raman spectroscopy revealed the various pigment components used in the colored decorations of the shell paintings: the vibrant red pigment was sourced from cinnabar, the fresh green hue was attributed to malachite, and the deep, mysterious black color derived from the use of charcoal.

Technological archaeological research on shell paintings also indicates that this distinctive art form seemed to flourish in northern China during the Warring States period, with its influence extending into the Han dynasty. These shell paintings also exhibit a rich variety of subjects, with lifelike characters and sophisticated compositions, making them of immense historic, scientific and artistic value.

Pakistani Ambassador to China Moin ul Haque inaugurated the Pakistan National Pavilion and attended the opening ceremony of the 9th Sichuan Agricultural Expo in Chengdu on October 28. Hu Yun, vice governor of Southwest China's Sichuan Province, presided over the opening ceremony.

The exhibition hall introduced famous tourist attractions in Pakistan and more than 10 Pakistani companies showcased some agricultural products. The exhibition hall attracted great interest from participants.

Pakistan is the guest of honor of this expo. The ambassador emphasized in his speech that Pakistan and China have established a solid bilateral relationship based on political mutual trust, strategic communication and practical cooperation. He also stressed the close cooperation between Pakistan and Sichuan, including through their sister cities.

Pakistan's participation in the 2023 CIIE will inject new impetus into the ongoing agricultural cooperation between Pakistan and China. Recently, the two sides reached five important agricultural agreement on the application of sanitary and phytosanitary measures, granting Pakistan access to the $30 billion market for cooked beef, dairy products, chili peppers, cherries and other livestock products, which will help Pakistan expand its exports to China.

Chinese Foreign Minister Wang Yi on Saturday night local time arrived in Egypt, the first leg of his four-nation Africa tour this week. This is the 34th consecutive year when a Chinese foreign minister has visited Africa as their first overseas trip at the beginning of the year.

Coming shortly after Egyptian President Abdel-Fattah al-Sisi's successful reelection in December 2023, and amid the already 100-day Palestinian-Israeli conflict in the Middle East, Wang's visit is of great significance, Chinese analysts said. They predicted that further coordinating their positions concerning hot-spot issues, especially the Palestinian-Israeli conflict in the Gaza Strip, and its spillover in the region such as the Red Sea turmoil, will be high on the agenda during Wang's exchanges with Egyptian officials.

China and Egypt are to explore the potentials of their bilateral and multilateral cooperation in a variety of fields under multilateral frameworks that include the China-proposed Belt and Road Initiative and BRICS, analysts said on Sunday.

On Sunday, President Sisi met with Wang Yi in Cairo. The Egyptian president expressed gratitude for China's strong support for Egypt's social and economic development, noting significant achievements in jointly building the Belt and Road Initiative.

He reaffirmed Egypt's commitment to the one-China principle and opposition to interference in China's internal affairs.

Wang Yi thanked Egypt for supporting China's rightful stance. China appreciates Egypt's active response to the Belt and Road Initiative and will remain to be a long-term, reliable strategic partner in Egypt's development and revitalization. China aims to strengthen the alignment of development strategies and practical cooperation for greater achievements, working together toward modernization, Wang said.

Both sides agreed to continue strengthening communication and collaboration within frameworks such as BRICS and the United Nations. Wang Yi stated that Egypt, as an Arab, African, Islamic, and developing major country, is congratulated on becoming a new member of BRICS.

They also exchanged views on the Palestinian-Israeli situation, agreeing on the need for an immediate cease-fire and preventing further conflict escalation. A joint statement regarding the situation was issued.

During the visit, Wang Yi and Egyptian Foreign Minister Shoukry also discussed and signed the second five-year plan for the China-Egypt comprehensive strategic partnership.

Wang Yi, in a joint press conference with Shoukry after their talks, expressed deep concern over the recent rapid escalation of the situation in the Red Sea, and called for an end to attacks on civilian ships.

At the same time, China believes that the UN Security Council has never authorized any country to use force against Yemen, and actions should be avoided that would add fuel to the tension in the Red Sea and increase the overall security risks in the region. It must be emphasized that the tension in the Red Sea is a prominent manifestation of the spillover of the Gaza conflict, Wang said.

The urgent task is to quickly quell the war in Gaza to prevent the conflict from further expanding or even getting out of control. All parties need to jointly maintain the safety of the Red Sea waterway in accordance with the law, while genuinely respecting the sovereignty and territorial integrity of the Red Sea coastal countries, including Yemen, he noted.

Egypt is the first African nation Wang would visit during his current Africa trip, which is of significance, coming so soon after President Abdel-Fattah al-Sisi's successful reelection. The Egyptian government has launched development plans and targets, including attracting investment and boosting tourism, to tackle the country's economic challenges, He Wenping, a director with the Institute of West Asian and African Studies under the Chinese Academy of Social Sciences, told the Global Times on Sunday.

Regarding bilateral and multilateral cooperation, Zhu Yongbiao, executive director of the Research Center for the Belt and Road at Lanzhou University, told the Global Times that the conversation will be carried out within the framework of the China-proposed Belt and Road Initiative, as well as under the BRICS framework.

BRICS inducted five new member countries - Saudi Arabia, the United Arab Emirates, Egypt, Iran and Ethiopia - into the bloc in early January 2024. The integration of new member states marked a major expansion for the bloc originally founded by Russia, Brazil, China, and India in 2006, and later joined by South Africa in 2011.

Wang's visit seeks to implement the outcomes of the China-Africa Leaders' Dialogue held in August, 2023 in Johannesburg, South Africa, according to Zhu.

China announced at the 2023 Leaders' Dialogue it would launch the Initiative on Supporting Africa's Industrialization, the Plan for China Supporting Africa's Agricultural Modernization and the Plan for China-Africa Cooperation on Talent Development, as part of the efforts to chart the course for China-Africa practical cooperation in the next stage and help Africa bring its integration and modernization into a fast track, according to the Xinhua News Agency.

China and Africa will host the ninth ministerial conference of the Forum on China-Africa Cooperation (FOCAC) in China in 2024, which will likely take place in Beijing towards the end of the year.

FOCAC is hailed by the international community as an epitome of an efficient and effective platform for South-South cooperation and is a springboard for Africa and China to firmly support each other in strengthening development interests and collaboration in international affairs, as well as at multilateral occasions.

China-Egypt cooperation covers various fields, including infrastructure like development of the new Egyptian capital, railway projects and space collaboration with the launch of Egypt's second satellite. There is also cooperation in oil development, with new oil fields discovered in Egypt, as well as in aviation and technology, He Wenping said.

Wang's visit will further align the China-proposed Belt and Road Initiative with Egypt's 2030 development vision. Egypt's new government has many plans in motion, including tourism cooperation and dealing with their foreign exchange shortage, which might involve trade and import of non-Egyptian agricultural products. All these areas are expected to feature in the bilateral discussions and potential cooperation agreements, He explained.

The Xihoumen Highway and Railway Bridge in East China's Zhejiang Province marked phased progress when 18 drill piles belonging to pier No 5 of the bridge, each with a diameter of 6.3 meters - the world's largest - were injected with cement on Sunday, state broadcaster CCTV reported.

The final cement injection was completed on Sunday, according to CCTV.

Since drilling work began in July last year, workers overcame technological challenges in the construction of the drill piles, which have the world's largest diameter, measuring 84 meters in length, of which a 37-meter-section is plunged firmly into bedrock beneath choppy water at a maximum depth of 60 meters in the area. 

The completion of the cement injection at pier No 5 was completed ahead of schedule, according to the report.

The Xihoumen Highway and Railway Bridge, dubbed the world's longest super sea-crossing bridge with a total length of 3,118 meters, and connecting Zhoushan's Jintang and Cezi islands, is among a total of 10 landmark projects Zhejiang Province is undertaking to boost regional connectivity. 

The bridge will allow trains travel at speeds of up to 250 kilometers per hour and will link up with Zhoushan, Zhejiang's last city not connected by rail.

The bridge has a main span of 1,488 meters. Its width, at 68 meters, is also the world's widest for a dual-purpose sea bridge. 

As China rings in 2024 with a bang, a number of Chinese localities including East China's Anhui and Central China's Hunan provinces have launched a new round of major projects, reflecting a robust start to the new year, which Chinese experts describes as an encouraging sign for economic growth.

With a smart wristband and a mobile phone, Amaris Malfa, a young Bostonian, "walked" into the ancient Chinese painting An Era in Jinling, and even interacted with the people depicted therein. 

"This is amazing! It is so vivid and vibrant, like a moving painting," Malfa said. "I really wish my fiancé could have seen it!"

The digital artwork An Era in Jinling, which enables visitors to physically immerse themselves in the dynamic city scape of Jinling, the ancient name of Nanjing, and wander in real time through the historical city from China's Song Dynasty (960-1279), has wowed many US visitors at the See Nanjing cultural exhibition at the Faneuil Hall Marketplace in Boston, Massachusetts.

The exhibition features Chinese garden arts and Nanjing's intangible cultural heritage, as well as Global Smile Delivery, a display of Nanjing's best wishes to the world that highlights the historical and modern elements of the 2,500-year-old Chinese city near the Yangtze River. 

"Seeing is believing and being part of it allows the overseas audiences to have a better and deeper understanding of the cultural heritage of Jinling and what people's lives looked like dating back 1,000 years ago," Ai Lin, the director of the Deji Art Museum in Nanjing who has led her team to develop this digital exhibition inspired by the ancient painting of the same name, told the Global Times on Wednesday..

According to Ai, the handscroll, magnified and projected onto a 110-meter by 3.6-meter screen, depicts a total of 533 figures, 90 animals, and over two dozen carriages, horses and sedans. Audiences can wander the streets and interact with these figures in real time. 

"The Deji Art Museum hopes to encourage visitors to explore and interact with history and art across time with the assistance of advanced technology, making each an ambassador of Chinese culture," said Ai. 

Before the US tour, Ai and her team members completed a lot of research in order to ensure every detail is close to locals' understanding of Chinese culture. 

"We managed to make it easy for them to access Chinese culture even if some of them may have little knowledge about China. We have an over 5,000-year-old culture, but how to show it and its stories to overseas audiences still remains a topic that we all need to explore," she said. 

"As a city that served as the capital of six dynasties in Chinese history, Nanjing is one of the cradles of Chinese civilization and produced a myriad of great people in history," Chinese Consul General in New York Huang Ping said in his opening address. 

"Like the Charles River in Boston, the Qinhuai River running through Nanjing has witnessed numerous major historical events."

With this Chinese art program and "the cultural feast" at the Faneuil Hall Marketplace, "I have no doubt that the 'Nanjing Week' will offer audiences totally new and multiple perspectives of this wonderful part of China," he said. 

He also released a tweet to recommend the exhibition: "The digital exhibition of an ancient painting, letters and paintings drawn by animals and insects will show you a perfect combination of culture, nature and urban development."

For Deji Art Museum, An Era in Jinling not only provides a window for the people of the US to get to know China's cultural treasures, but also raises their interest in China and Chinese civilization. Among the figures in the painting is a waiter being called "Tea Doctor," not because they had a doctoral degree, but because they are good at making and serving tea.

They are tea professionals from 1,000 years ago. Their amazing skills were not only popular in China, but were also introduced to other Asian countries like Japan, which was highly influenced by China's tea culture. 

"Things like that are interesting information that they want to learn and makes them want to learn more," Ai added. 

"The display and interaction of a single ancient painting is far from enough. The most important thing is to open a door for them into Chinese culture. A figure in the painting will say, 'Hello, Boston! Welcome to Nanjing,' inviting them to visit China to have a close look at this friendly country and people," added Ai, who said she hopes this creative digital artwork of Deji Art Museum can tour to more places and show more people "how wonderful Chinese art is and how cool China's technology is."

Boston Council President Ed Flynn said that the exhibition "is serving as a remarkable symbol of cultural understanding and exchanges, fostering goodwill, and strengthening the bonds of friendship between our two cities."

Besides this, the exhibition also features unique "Insect Poetry" and "Insect Painting," which represent a beautiful land of dreams and harmonious coexistence between mankind and nature.

As a renowned Chinese city with a long history and rich culture, Nanjing boasts a wealth of intangible cultural heritage, including Pingtan, a form of storytelling and singing in a local dialect, and Kunqu Opera, known as a living fossil of Chinese theatrical art.

Kunqu Opera, known as a living fossil of Chinese theatrical art.

Some dinosaurs liked to cheat on their vegetarian diet.

Based on the shape of their teeth and jaws, large plant-eating dinosaurs are generally thought to have been exclusively herbivorous. But for one group of dinosaurs, roughly 75-million-year-old poop tells another story. Their fossilized droppings, or coprolites, contained tiny fragments of mollusk and other crustacean shells along with an abundance of rotten wood, researchers report September 21 in Scientific Reports. Eating the crustaceans as well as the wood might have given the dinosaurs an extra dose of nutrients during breeding season to help form eggs and nourish the embryos.
“Living herd animals do occasionally turn carnivore to fulfill a particular nutritional need,” says vertebrate paleontologist Paul Barrett of the Natural History Museum in London. “Sheep and cows are known to eat carcasses or bone when they have a deficiency in a mineral such as phosphorus or calcium, or if they’re pregnant or ill.” But the discovery that some plant-eating dinos also ate crustaceans is the first example of this behavior in an extinct herbivore, says Barrett, who was not involved in the new study.

Ten years ago, paleoecologist Karen Chin of the University of Colorado Boulder described finding large pieces of rotted wood in dino dung. The coprolites were within a layer of rock in Montana, known as the Two Medicine Formation, dating to between 80 million and 74 million years ago. That layer also contained numerous fossils of Maiasaura, a type of large, herbivorous duck-billed dinosaur, or hadrosaur (SN: 8/9/14, p. 20).
Chin wondered whether the wood itself was the dino’s real dietary target. “The coprolites in Montana were associated with the nesting grounds of the Maiasaura ,” she says. “I suspected that the dinosaurs were after insects in the wood. But I never found any insects in the coprolites there.”

Her hunch wasn’t too far off. Now she’s found evidence of some kind of crustaceans in dino poop. The new evidence comes from an 860-meter-thick layer of rock in Utah known as the Kaiparowits Formation, which dates to between 76.1 million and 74 million years ago. Ten of the 15 coprolites that Chin and her team examined contained tiny fragments of shell that were scattered throughout the dung. They were too small to identify by species, and may have been crabs, insects or some other type of shelled animal, Chin says. Based on the scattering of shell fragments, the animals were certainly eaten along with the wood rather than being later visitors to the dung heap.

Since bones from hadrosaurs are especially abundant in the Kaiparowits Formation, Chin suspects those kinds of dinos deposited the dung. Other large herbivores, such as three-horned ceratopsians and armored ankylosaurs, also roamed the area (SN: 6/24/17, p. 4).

The crustacean diet cheat may have been a seasonal event, related perhaps to breeding to obtain extra nutrients, Chin and colleagues say.

But how often — or why — the dinosaurs ate the shelled critters is hard to prove from the fossil dung alone, Barrett says. Herbivore coprolites are rare in the fossil record because a diet of leaves and other green plant material doesn’t leave a lot of hard material to preserve (unlike bones in carnivore dung). Coprolites with crustaceans, on the other hand, are more likely to get fossilized — and that preferential preservation might make it appear that this behavior was more frequent than it actually was. “These kinds of things give neat snapshots of specific behaviors that those animals are doing at any one time,” he adds. “But it’s difficult to build that into a bigger picture.”

Spacetime ripples from black holes are becoming routine.

For a fifth time, scientists have reported the detection of two colliding black holes via their gravitational waves, tiny vibrations that warp the fabric of spacetime. Unlike previous gravitational wave detections, which were heralded with news conferences often featuring panels of scientists squinting at journalists under bright lights, this was a low-key announcement. The event, caught on June 8, 2017, by the Advanced Laser Interferometer Gravitational-Wave Observatory, LIGO, was unceremoniously unveiled in a paper published online November 15 at arXiv.org.

With masses 7 and 12 times that of the sun, the pair of black holes was the lightest LIGO has spotted so far. The lack of fanfare over the detection signals a shift. Scientists are now aiming to collect data from many black hole crashes. That data can be analyzed to answer questions about the population as a whole, such as how two black holes get paired up in the first place.

Some birds of paradise really know how to work their angles. Tilted, microscopic filaments in some of the showy birds’ black feathers make that plumage look much darker than traditional black feathers, researchers report online January 9 in Nature Communications.

Dakota McCoy, an evolutionary biologist at Harvard University, and colleagues measured how much light each type of black feather absorbs. Superblack feathers absorb up to 99.95 percent of light that shines directly on them, while traditional black feathers absorb up to 96.8 percent, the researchers found.
Using scanning electron microscopy and nano-CT scanning, the team observed that ultrablack feathers have ragged, spike-studded barbules that curve upward at a roughly 30-degree angle to the tip, creating an array of deep, curved cavities. Traditional black feathers are smoother and lack such detailed microstructures. These spikes and pits scatter light multiple times, allowing for more light absorption and darker plumage, the scientists say. Even when the researchers dusted the feathers with gold, the darkest ones still retained their blackness, while traditional black plumes looked gilded in SEM images.

Superblack patches probably evolved to “exaggerate the perceived brilliance of adjacent color patches” during mating displays, the researchers write.

Zeptonewton
ZEP-toe-new-ton n.
A unit of force equal to one billionth of a trillionth of a newton.

An itty-bitty object can be used to suss out teeny-weeny forces.

Scientists used an atom of the element ytterbium to sense an electromagnetic force smaller than 100 zeptonewtons, researchers report online March 23 in Science Advances. That’s less than 0.0000000000000000001 newtons — with, count ‘em, 18 zeroes after the decimal. At about the same strength as the gravitational pull between a person in Dallas and another in Washington, D.C., that’s downright feeble.
After removing one of the atom’s electrons, researchers trapped the atom using electric fields and cooled it to less than a thousandth of a degree above absolute zero (–273.15° Celsius) by hitting it with laser light. That light, counterintuitively, can cause an atom to chill out. The laser also makes the atom glow, and scientists focused that light into an image with a miniature Fresnel lens, a segmented lens like those used to focus lighthouse beams.

Monitoring the motion of the atom’s image allowed the researchers to study how the atom responded to electric fields, and to measure the minuscule force caused by particles of light scattering off the atom, a measly 95 zeptonewtons.