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If you cook on a gas stove, the food heats faster when it's closer to the flame. But in seeming defiance of thermodynamics, that doesn't work when you're talking about the sun. While the solar surface is about 10,000 degrees Fahrenheit, the atmosphere can hit a whopping 9 million degrees in its outer reaches, called the corona, and scientists have been asking, "What's up with that?" for decades.
Now a team at the École Polytechnique in France thinks they have at least part of the answer. Using new computer models, they posit that the ultimate source of the corona's searing heat is a "mangrove forest" of magnetism that lies just underneath the surface we see, called the photosphere.
"Everyone knows that the energy is coming from below, and we know it's a lot of energy," says study leader Tahar Amari. The question has been what creates that energy and how it travels from the surface to the corona. That's where the new model, described this week in Nature, steps in.
The sun is made mostly of plasma, hot gas made of atoms that have had their electrons stripped away, creating a charge. When that kind of gas is rotating, it acts like an electrical generator, or a dynamo. In the new model, the sun's plasma creates these dynamos as it roils and churns. The dynamos in turn generate magnetic fields, which can store energy. All this occurs in the upper 900 miles of the sun—a small fraction of its 432,000-mile radius. The dynamos don't last long, about eight minutes on average, but it's enough that they can sometimes feed larger structures.
When the resulting magnetic fields twist, turn and cross each other, they can release their energy in a phenomenon called reconnection. Put two or more fields near each other, and the poles of those fields try to create new magnetic field lines with their nearest neighbors, rearranging the shapes of the fields in the process. Excess energy then gets expelled as heat, electromagnetic waves or kinetic energy, and that in turn gets pumped into the chromosphere, the layer extending about 1,200 miles from the photosphere to a region that transitions into the corona.
According to the model, the energy dump fuels eruptions of plasma into the chromosphere, which make waves akin to sound waves moving through the air. These are called Alfvén waves, after physicist Hannes Alfvén, who first proposed their existence in the 1940s. The Alfvén waves' energy gets dissipated in the corona, which then gets hot enough to reach the millions of degrees we observe.A model of the complex magnetic field sprouting from the sun’s surface highlights the resemblance to the roots and branches of mangrove trees. (Tahar Amari /Centre de physique théorique.CNRS-Ecole Polytechnique.FRANCE)
Amari likens the whole system to a mangrove forest. At the bottom are the roots, which come together to form the trunks of the trees. The top of the trees is where the energy gets deposited. He noted that to get the kind of coronal heating we see, you need about 4,500 Watts per square meter from the surface, and that's what his model produces.
For now, the work is only a computer simulation, and there isn't yet a direct way to observe what's happening, Amari says. However, existing indirect observations of the sun make his model plausible. For instance, the coronal temperature doesn't seem to vary much with the 11-year sunspot cycle. "Sunspots are sensitive to the cycle—this magnetic field is not," Amari says. Sunspots are magnetic disturbances rooted deeper in the sun, so if the two phenomena are not linked, that would support Amari's model of a relatively shallow driver for coronal heating.
Another factor is the discovery of solar tornadoes, which show that some phenomena can transport energy from the surface to the chromosphere and corona, bolstering the model. In addition, observations of the solar surface show that the spectral lines of some elements are split into two or more components, which happens if there's a strong local magnetic field like the one the model describes.
Last year Jeff Brosius, a solar physicist at the NASA Goddard Space Flight Center in Greenbelt, Maryland, proposed that tiny flares called nanoflares were responsible for coronal heating. Nanoflares are caused by huge magnetic fields that loop through the corona. The magnetic field lines sometimes cross, creating current sheets that release energy as heat.
While the two versions differ in their specifics, they aren't necessarily contradictory. "The mechanism of the nanoflares is an open question," says Jim Klimchuk, a research astrophysicist at Goddard who wasn't involved in either study. "It could involve the reconnection of magnetic fields in the corona (the same process that creates Amari's mini eruptions below the solar surface and that causes them to deposit most of their energy in the chromosphere), or it could involve the dissipation of waves that are launched into the corona from below. I'm sure both things are happening. It's just a question of proportion."
According to Klimchuk, the new model is an important step in understanding this vexing solar mystery. "To my knowledge, [the dynamos producing eruptions in the chromosphere] have not been seen in other simulations, so it will be important to work out the details of this behavior and verify that it is correct," he says. "The chromospheric and coronal heating problem is not solved, but these results may provide important clues as to the path forward."
EDITOR'S NOTE: This article has been updated to clarify that dynamos have been seen before in solar models.
Lord Rosse directing the conveyance of the Great Speculum to its position at the Base of the Tube, North Side
Imagine you just got married, and a few months later you had the opportunity to relive your celebration three more times with a different crowd of guests. One real wedding followed by three recreations.
This was the case for newlyweds Mariam Hovhannisyan and Stepan Toroyan, who were married in Armenia a year before flying out to Washington, D.C., to participate in the 2018 Folklife Festival. Both members of Yerevan-based dance troupe Menq, they played the role of bride and groom in this festive recreation of a traditional Armenian wedding, known as a harsanig. The hour-long celebration combined a mélange of rituals accompanied by music, dance, and a narration that revealed a world of symbolism.
The piercing sounds of the zurna (woodwind instrument) and kopal (large, double-headed drum) provided an insistent invitation for Folklife Festival community to come together and celebrate. Accompanied by these euphoric tunes, participants performed several folk dances with choreographic variations as they wove in and out of crowds, at times encircling the bride and groom.
A couple of dance highlights included the shabash and yarkhushta. During shabash, guests typically throw money to the bride and groom, wishing them wealth and prosperity. They don’t get to keep the money, though—it is swept up later and given to the musicians. The yarkhushta, the masculine militant “clap dance,” also drew a lot of attention. Men face each other in pairs and rapidly approach one another resembling leaping goats. This produced an irresistible adrenaline rush, for both dancers and spectators.
As the public observed these dances and other rituals, program curator Levon Abrahamian reminded them that each region in Armenia has its own wedding ceremony style. Despite the slight variations, much of the symbolism remains the same. Here are a few other rituals and symbols that were part of the recreated ceremony:
Lavash flatbread: The mother-in-law places lavash on the shoulders of the bride and groom as a sign of prosperity and abundance.
Breaking plates: The bride and groom break plates before entering their new home as a way to cast off any evil. According to tradition, whoever breaks the plate first assumes authority in the house!
Honey and walnuts: As they enter the groom’s house, the mother-in-law gives the bride and groom a spoonful of honey and walnuts, wishing them a sweet life.
Flourished apple: Known in Armenian as tzaghkatz khndzor, the groomsman holds a knife with an apple at the top (seen in video) filled with dimes and quarters, which were traditionally real gold and silver coins. The rest of the sword is draped with red and green ribbon (red for the bride, and green for the groom) as well as other candies, signifying the start of a sweet life for the new couple.
Wedding gata: This sweet Armenian pastry is given to young, unmarried girls as a symbol of prosperity and blessing.
Khorovatz: Participants sway khorovatz, or grilled meat on a stick, in the air as they dance their way through the crowds.
Toastmaster: An Armenian wedding is not complete without the toastmaster tradition. Both the godfather and mother-in-law express beautiful words of appreciation for the bride and groom, followed by poetry and song (in the video, notice the red and green ribbon on the toasting glasses).
Bride’s dowry: The bride’s family presents various items to the groom’s family, including a cover for the bed, a tablecloth, a blanket for the baby, and a silk rug (considered the dowry’s masterpiece!). All these pieces, handmade by the bride (or in our case, by other Festival participants), are symbols of her patience and reveal the strength of her eyesight, because it takes a lot of effort and hard work to create these works of art.
Click on the photo above to view full slideshow
The real beauty of this harsanig ceremony on the National Mall was how the community of Armenian compatriots came together in a collective spirit to share this tradition with visitors, inspiring intercultural dialogue and curiosity among spectators. The stone carvers, carpet weavers, needle workers, and lavash bakers, among others, expressed such joy and enthusiasm as they immersed themselves in their roles during the ceremony. As a spectator, you would have thought they were two real families celebrating a real wedding.
In reality, however, most of the wedding festivity roles were spontaneous and improvised. The only information they received in advance was that a session on traditional Armenian weddings would take place. The rest was left to their own memory and traditional knowledge.
Micaela A. Nerguizian is a production consultant in the performing arts and intern at the Smithsonian Center for Folklife and Cultural Heritage. She is completing her graduate degree at the Middlebury Institute of International Studies, with a focus on cultural diplomacy and international education. As an Argentine of Armenian descent who has attended several Armenian weddings, she has never experienced a ceremony quite like this one.
Two young men dressed in white kneel on the ground, ready to begin their duel. Eyes lock onto those of his opponent. Hearts beat faster. Ancestral sounds echo forth from the berimbau, a single-stringed bow-shaped instrument. Only then do the two shake hands, and the match may commence. With a dynamic, animal-like force, the two exchange movements of attack and defense in a constant flow of exploring and exploiting each other’s strengths and weaknesses, fears and fatigues. They wait and watch patiently for that careless moment in which to drive home a decisive blow.
Capoeira developed in Brazil, derived from traditions brought across the Atlantic Ocean by enslaved Africans and fueled by the burning desire for freedom. It soon became widely practiced on the plantations as a means of breaking the bonds of slavery, both physically and mentally. During this time, the art was considered a social infirmity and officially prohibited by the Brazilian Penal Code. The identification of “the outlaw” with capoeira was so widespread that the word became a synonym for “bum,” “bandit,” and “thief.” However, that did not stop the capoeiristas from practicing. They moved to marginal places and camouflaged the martial art as a form of dance.
Today, we find people all over the world practicing capoeira, not only in parks and studios but also universities and professional institutions. It took a central role at this year’s Smithsonian Folklife Festival, where the On the Move program explored the journeys people take to and within the United States and the cultures, stories, and experiences they carry with them. Capoeira is a result of the phenomenon of people migrating to new lands. As Mestre Jelon Vieira explained during the Festival, “Capoeira was conceived in Africa and born in Brazil.”
The Tradition: Resistance and Resilience
Between 1500 and 1815, Brazil was a colony of the Portuguese Crown—an empire sustained by slave labor. The business of capturing and selling humans brought enormous wealth to the Portuguese Crown, but it brought huge numbers of enslaved Africans to the New World. Hundreds of people were packed into overcrowd, infected holds of slave ships in order to maximize profit. As a result of the perilous and unhealthy conditions during the three-month journey, more than half of the enslaved lost their lives, their limp bodies tossed overboard.
Upon arrival, they were sold at the Sunday market and sent to work in the hot, humid, and harsh conditions of the plantations, where many would be worked to death. The high mortality rates among the enslaved populations in Brazil, along with an increased demand for Brazilian raw materials like sugar, gold, and diamonds, spurred the importation of growing numbers of Africans. An estimated four million enslaved people were shipped to Brazil until the mid-nineteenth century.
The enslaved resisted in various forms: armed revolt, poisoning their owners, abortion, and escape. The vastness of the Brazilian inlands made it possible for individuals on the run to hide. Some escaped and formed clandestine communities in the backlands of the rainforest, independent villages known as quilombos. Here, the Africans and their descendants developed an autonomous socio-cultural system in which they could sustain various expressions of African culture. Historians surmise that capoeira emerged from these communities as a means for defense under the oppressive Portuguese regime.
By the mid-1800s, the towns and cities of Brazil experienced an unprecedented urbanization. Cities grew in population but lacked adequate economic planning and infrastructure, resulting in a growing population of vagrants. The Paraguayan War between 1864 and 1870 brought a flood of veterans and refugees from destroyed quilombos into the cities. These people were attracted to capoeira not only for its sport and play but also for its powerful means of attack and defense for their survival.
Capoeira became a widespread practice at the beginning of the twentieth century—outlaws, bodyguards, and mercenaries used it. Even some politicians practiced as a way to sway constituents. In this time, strong social pressure throughout the country slowly transformed capoeira into a less aggressive weekend pastime. Eventually capoeiristas were meeting in front of bars, playing an apparently inoffensive kind of dance accompanied by berimbaus.
The oppression of capoeira diminished significantly during the 1930s. During this time, a particular mestre—or master—had been working toward restoring the dignity and historical perspective of the capoeira of his time. Mestre Bimba was born in 1899 in Bahia, in northwestern Brazil. In 1932 he became the first master to open a formal capoeira school called Luta Regional. By 1937, the school received official recognition by the government. The course of capoeira had changed.
Mestre Bimba established a disciplined method of teaching and legitimized capoeira as a form of self-defense and athletics. He developed a style called capoeira regional, which emphasized the technicality of movements and a dance-like nature. When he was summoned by the government to perform in front of distinguished guests, Mestre Bimba became the first to publicly present capoeira as an official cultural practice.
Capoeira on the Move
Mestre Bimba’s success sparked the growth of new schools in Bahia. As capoeira received more and more public affirmation, the younger mestres found better environments for new expression. Many of them left Bahia to teach in places like Sao Paulo and Rio de Janeiro, taking the opportunity to develop their own styles. Contemporary capoeira was distinguished by its emphasis on cleanliness and articulation, a paramount fighting technique but also an innovative, spectacular visual show.
The 1960s marked a major turning point for the tradition. In 1964, Mestre Acordeon created the Grupo Folclórico da Bahia to share capoeira in a more organized and formal way. He and his group toured the country, reached into local schools, and won recognition in international competitions. Soon after, he founded the World Capoeira Association with the goals of promoting exchange through workshops, educational trips, and publications, and codifying a body of rules for the understanding and respect for the history, rituals, traditions, and philosophy.
In 1972, the Brazilian government recognized capoeira as on official sport. The regulations laid down rules, definitions, bylaws, a code of ethics, recognized movements, and a graded classification chart for students. It also established rhythms for the music and guidelines for the role of the berimbaus during competition.
This institutionalization and systemization of capoeira did not sit well with many mestres. They were opposed to such formalizing efforts, which they saw as an attempt to remove the art from its more organic, grassroots environment. Despite their opposition, capoeira was already engaged in a tremendous process of adapting to a changing society.
Capoeira was growing, spreading to different parts of Brazil and soon around the world. It took root in the United States in the mid-1970s when Mestre Jelon Vieira and Mestre João Grande introduced their art to new audiences. Since then, these two influential masters have dedicated their lives to growing a community of capoeiristas.
Mestre Jelon Vieira was born in 1953 in Bahia, Brazil. He moved to New York City in 1975 and planted the first seeds of capoeira in the United States. Aside from touring the country, the Caribbean, and Europe with his company, DanceBrazil, Vieira has been teaching in under-resourced communities and at institutions of higher learning such as Columbia University, Yale, Harvard, and New York University. He is sure to immerse his students not only in the techniques of capoeira but also in the philosophy. Many people suggest that Mestre Jelon may be responsible for the incorporation of capoeira movements into modern-day breakdancing.
Encouraged by Mestre Jelon, Mestre João Grande, also from Bahia, founded his own academy in New York City in 1990, where he has trained thousands of students in the tradition of capoeiraAngola. Both men have been recognized for their mastery and commitment to passing on their traditions of capoeira with the National Endowment for the Arts National Heritage Fellowship, our nation’s highest honor in folk and traditional arts.
Mestre Jelon and Mestre João Grande were featured in the Folklife Festival, where they discussed and demonstrated their art for visitors on the National Mall. They brought students in their academies from around the United States to Washington, D.C., and led interactive lessons with the public. The Festival provided a platform to share the voices and experiences of an ancient and unique tradition of Afro-Brazilian descendants. In a discussion session, Mestre João Grande explained his inspiration and how he first learned capoeira.
“I looked everywhere to learn capoeira,” he said. “When I couldn’t find capoeira, I started to observe nature—how the animals survive, how they fly, how they hunt, how the animals behave, how the fish swim, how they fight in the water, how the birds fly and never touch each other, how the wind hits the trees, how the trees move then become still again, how the snake moves on the ground, how the dogs play with humans and each other, how the hurricane turns.
“That is what inspired me—nature. Capoeira is nature.”
Juan Goncalves-Borrega is a curatorial intern at the Center for Folklife and Cultural Heritage working with the 2017 On the Move program. He is pursuing a bachelor of arts in history and a bachelor of science in anthropology at Virginia Commonwealth University.
Coretta Scott King observes the program from her seat with actor Harry Belafonte and members of her family
Consists of: Edison Diamond Disc.
2011.81.2: Edison diamond disc.
Side 1: This is a recording of a vaudville comedy sketch of a conversation on a train between two African American porters. It is likely a blackface performance. One is confronting the other after finding him in the observation car not working. They begin comically discussing the various passengers they're serving. The humor of the sketch plays on one of the porter's laziness and igorance.
Side 2: This is a recording of a vaudville comedy sketch of two African American men in a rowboat. It is likely a blackface performance. The two men have been rowing for many hours, but appear to be going in circles. The humor of the sketch plays on one of the men's ignorance and confusion with language.
13.8 billion years ago, in a cacophonous event, our universe was born.
Yet new planets are still condensing from swirling clouds of hydrogen and helium and filling the sparking horizons. With increasingly bigger, and better telescopes, astronomers have even identified a handful of planets that could be ripe for potential life. But according a recent study, 92 percent of possible Earth twins have yet to be born, reports Sid Perkins for Science.
This surprising statement comes from two researchers based at the Space Telescope Science Institute in Baltimore, Maryland, Peter Behroozi and Molly S. Peeples. To guess the universe's planetary potential, the duo developed a model that uses known information about the ethos—like how planets form, the age of observed galaxies, and estimates for the amount of matter in the universe.
The result? The universe has potential to form more than ten times the number of planets than exist today, according to their study recently published in the Monthly Notices of the Royal Astronomical Society.
"Our main motivation was understanding the Earth's place in the context of the rest of the universe," Behroozi says in a press release. Earth is a fairly young planet in astronomical time, but on a larger scale, this research suggests that it will eventually be the older sibling of the universe.
Since the beginning of our universe, the rate of planet formation has slowed overtime. But there’s still plenty of material for the birth of many more planets and stars. According to the model, the last star in the universe shouldn’t burn out until 100 trillion years in the future, writes Pete Spotts for The Christian Science Monitor.
As those many, many millennia churn on, chances become increasingly better that life will arise somewhere other than Earth (if it hasn’t already).
The universe is already full of wondrous planets—waterworlds, diamond planets and molten infernos. But these discoveries are only a small fraction of what is out there, an an even smaller one of what is yet to come.
In 1925, 24-year-old high school teacher John Thomas Scopes was tried in Dayton, Tennessee, for teaching about evolution, in violation of a newly enacted state law.
During the first week of June 1925, 29-year-old Watson Davis, managing editor of Science Service, a Washington, D.C.-based science news organization, traveled to Dayton to meet Scopes. The journalist then returned the following month to report on the trial, which began on July 10.
On Monday, July 20, 1925, 19-year-old William Silverman, who had just graduated from high school in nearby Chattanooga, went to Dayton with one of his science teachers to observe the proceedings. Fortunately, like Davis, Silverman took along his camera.
This special slide show, weaving together the photographs of Davis and Silverman, is presented by the Smithsonian Institution Archives to mark the 90th anniversary of the Scopes Trial and to honor the work of two photographers who preserved these fascinating glimpses of people, places, and events.
- New Donation of Scopes Trial Photos to the Smithsonian Archives, The Bigger Picture blog, Smithsonian Institution Archives
- Tennessee v. John Thomas Scopes photographs, Smithsonian Flickr Commons
- Accession 10-042: William Silverman Photographs, 1925, Smithsonian Institution Archives
- Science Service collections at the Smithsonian Institution Archives
The stamps were issued in panes of thirty and have a perforation of 13 1/4 x 14. IPS, Rome, printed 1,600,000 complete sets in five colors, offset, on glossy white paper.
"Centenary of the Universal Postal Union." Vatican Notes 23, no. 1 (July-August 1974): 1.
Robots are getting better at everything. Including sex. Vibrator technology is advancing swiftly, with products like Vibease, which adjusts its speed based on voice cues from erotic e-books, and teledildonic apps that can control a vibrator from afar. It won’t be long until sex robots move from being experimental, fringe-bots to widely available technology—and nearly 10 percent of people are ready for it. In a survey by YouGov and the Huffington Post, 9 percent of participants said they would have sex with a robot if they could.
But there is a whole suite of questions that arise when sex robots become a reality. For instance, is having sex with a robot cheating? Forty-two percent of respondents said that it would be, while 31 percent said it wouldn’t. A quarter of people, however, were unsure. Which is characteristic of these sorts of questions. At FastCo Labs, Michael Grothus writes about this weird conundrum:
Sex with a vibrator = not cheating.
Sex with a vibrator that has legs and eyes and a face = cheating.
Ironically, it’s the possibility of sex with inhuman robots that reveals something very human about our concept of what sex is. To humans sex is more than mechanics and pleasure; it’s emotion and connection, which are primarily conveyed through human-only traits, like eye contact, empathy, and a partner’s careful observation. But one day machines will be able to convey those traits, and when that happens is when the real debate over sex and technology begins.
Once sex robots become available, it’s likely that more than 9 percent of people will at least consider trying them out. And when they do exist, we’ll have to face these questions of machine infidelity head on.
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