Solar Eclipse Myths

The Demons of Darkness Will Eat Men, and Other Solar Eclipse Myths[1]

An annular eclipse as seen from Arizona in 2012. Many ancient civilizations saw eclipses as bad omens. Credit Stan Honda/Agence France-Presse — Getty Images

 

We understand the cosmic calculus that leads to solar eclipses like the one that enchanted many Americans on Monday, August 22, 2017

But even for the most jaded skygazers, a solar eclipse can provoke a visceral sense of wonder that the phenomenon provoked long before it was understood.

Here’s a glimpse at the way that populations around the world understood solar eclipses, and used them to reinforce cultural norms and values.

An aberration

“This is something wrong. We’ve got to figure out what.”

That, said Dr. David Dearborn, an astrophysicist at Lawrence Livermore National Laboratory in Livermore, Calif., was frequently the response of ancient civilizations to the onset of a solar eclipse, particularly when they were unaware that the phenomenon would occur.

“If you were the Greeks, before they came to have an understanding of eclipses, you might think it was a bad omen, something the gods were telling you you had done wrong,” he said. “If you were the Chinese, you thought dragons were eating the Sun.”

“If you read the ‘Anglo-Saxon Chronicle’ — which is a really boring read — but if you scan through it, you’ll find lots of instances of eclipses, all related to other bad things,” he added.

Anthony Aveni, a cultural astronomer and the author of the 2017 book In the Shadow of the Moon: The Science, Magic and Mystery of Solar Eclipses, said that in every culture that he was aware of, solar eclipses were seen as cosmic “interruptions.”

For instance, he said, the Arapaho Plains Indians, who saw the celestial bodies as siblings, a brother Sun and a sister Moon, were alarmed to see that the two were suddenly converging. An obvious question was prompted, Mr. Aveni said: “What are they doing having sex in the sky?”

Understandably, the eclipse was thought by many cultures to herald the apocalypse. Susan Milbrath, the curator of Latin American art and archaeology at the Florida Museum of Natural History, provided a list of those who believed that solar eclipses could signal end times.

The Ch’orti’, indigenous Mayas, believed “an eclipse of the Sun that lasts more than a day will bring the end of the world, and the spirits of the dead will come to life and eat those on earth,” she wrote in an email, drawing on her book, Star Gods of the Maya: Astronomy in Art, Folklore, and Calendars.

Other Mayas including the Yucatec and the Lacandón associated eclipses with total destruction, she said. The Lacandón, who still live in what is now the Mexican state Chiapas, expected that Earth would split and that jaguars would emerge “and eat most of the people.”

The Florentine Codex, a ethnographic study of 16th-century Aztecs in Mexico, described a solar eclipse in particularly vivid terms:

There were a tumult, and disorder. All were disquieted, unnerved, frightened. Then there was weeping. The commonfolk raised a cup, lifting their voices, making a great din, calling out shrieking. People of light complexion were slain as sacrifices; captives were killed. All offered their blood. They drew straws through the lobes of their ears, which had been pierced. And in all the temples there was the singing of fitting chants; there was an uproar; there were war cries. It was thus said: “If the eclipse of the Sun is complete it will be dark forever. The demons of darkness will come down. They will eat men!”

Biting, eating, swallowing

Laura Danly, an astrophysicist and the curator of the Griffith Observatory, was one of many researchers who pointed out how commonly people interpreted solar eclipses as the Sun being eaten by some horrible creature.

“It’s a natural thing to think if you’ve ever seen one,” Dr. Danly said. ”The Moon literally looks like it’s taking a bite out of the Sun until it consumes it completely.”

Since the Sun always reappears, she said, “some throwing up or regurgitation is often a part of the story as well.”

An intricate version of the story related by Dr. Danly involved the Sun being eaten by a decapitated head of a Hindu demon, Rahu. The god Vishnu, warned by the Sun and the Moon, caught Rahu drinking the elixir of life and as punishment sliced off the demon’s head before the elixir passed through his throat. The immortal head takes his revenge on the celestial bodies by devouring them, but because he has no body, they re-emerge after he swallows them.

Not all the tales are quite so elaborate. Many involve predators in a given region devouring the Sun: in North America, dogs and coyotes; in South America, big cats like pumas; in what we now call Vietnam, unusually, a very large frog.

Reinforcement of cultural norms

Mr. Aveni pointed out that when we understand how myths functioned for the peoples who created them (rather than outsiders interpreting their tales), it is easy to see how they helped to reinforce cultural norms.

For instance, for the Arapaho, he said, the coupling of the Sun and the Moon prompted a discussion of sex and incest. In the Andes, where an Inca-related people believed that the Moon was whispering lies into the Sun’s ear, solar eclipses provided an occasion for a discussion about the evils associated with lying.

“I think we need to pay more attention to how these other cultures around the world regard nature instead of tending as we do to dismiss their ideas as silly,” Mr. Aveni said.

And finding the eclipse moving—and a little terrifying—is not an experience that was left behind with premodern people.

Dr. Danly is traveling to Jackson Hole, Wyo., where she used to spend time as a child, for the eclipse. She expected to experience an intensity of meaning that the myths may have helped accommodate.

“In our modern day, to give it meaning, you’ve really got to see the thing,” she said. “It’s so beautiful, it’s life-changing. And in that way makes us connect to what our ancestors might have felt and experienced.”

[1] See Jonah Engel Bromwich, “The Demons of Darkness Will Eat Men, and Other Solar Eclipse Myths,” The New York Times (August 18, 2017). A version of this article appears in print on August 19, 2017, on Page A13 of the New York edition with the headline: “The Demons of Darkness Will Eat Men, and Other Solar Eclipse Myths.” Follow Jonah Bromwich on Twitter: @Jonesieman

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Painting an Eclipse

Celestial Brushwork[1]

A 1925 painting by Howard Russell Butler in “Transient Effects: The Solar Eclipses and Celestial Landscapes of Howard Russell Butler,” at the Princeton University Art Museum. Credit Princeton University Art Museum

 

 

A third of the way through “Macbeth,” right after the antihero murders the king of Scotland, two noblemen look up into the sky and behold a celestial horror. “By the clock, ’tis day,” says the Thane of Ross, “And yet dark night strangles the traveling lamp.” The Sun has been blotted out over the Highlands, and Ross has a sense of why; the political has become astronomical, and crimes on Earth are reflected above.

On Monday, August 21, 2017, the Sun goes out over America, as a total solar eclipse passes over the width of the continental United States for the first time since 1918. It may be tempting, for some, to take a Macbethian reading of the country plunged into waking darkness for the first time since World War I—but now we know better (don’t we?) than to blame governments for the transit of heavenly bodies. A solar eclipse occurs whenever the Moon passes between Earth and the Sun; they are so predictable that NASA offers a search engine of future eclipses out to the year 3000.

 

 

A 1923 painting of a solar eclipse by Butler. Credit Princeton University Art Museum

 

 

When that 1918 eclipse passed over the United States, a team of astronomers invited the artist Howard Russell Butler to join them at an observatory in Oregon, and to document what will appear in untold millions of blurry Instagrams on Eclipse Day afternoon. It was the first of four eclipses that he saw, and his paintings of lunar transits and other celestial phenomena are on view in “Transient Effects: The Solar Eclipses and Celestial Landscapes of Howard Russell Butler,” a small, lovely show at the Princeton University Art Museum. His soft-colored, scrupulously accurate paintings of the occluded Sun were among the first artistic depictions of individual eclipses, and they document just what an observer in a given spot would have seen. They offer a jolly curtain raiser for Monday’s eclipse, and also continue a recent vogue for exhibitions that marry art and science.

 

 

 

 

 

 

 

 

 

 

 

 

Butler’s “Northern Lights, Ogunquit, Maine.” Credit Princeton University Art Museum

 

Butler (1856-1934) was a prosperous alumnus of Princeton’s science school, but in his 20s he turned to painting and arts advocacy. (He was president of Carnegie Hall for nearly a decade.) At first he concentrated on portraiture and landscape, but his scientific training came in handy when he beheld an aurora borealis off the coast of Maine. Rather than attempt to paint the streaks of green, turquoise and violet while outside, he quickly sketched the shapes and contours of the aurora and then made exacting notes on its shades. A century before Photoshop taught us to designate colors via numerical values of hue, saturation and luminosity, Butler employed formulas to designate what colors went where, and used both his notes and his sense memories to paint the cosmos.

 

 

 

 

 

 

 

A document detailing some of Butler’s notes from the 1918 total eclipse of the Sun. Credit Princeton University Art Museum

 

That piece-by-piece approach was essential for Butler when he joined the eclipse exhibition of 1918. Like most of the Americans who will see the totality of Monday’s eclipse, Butler had never seen the Sun obscured before, and he had only two minutes to watch the Moon block all of its light except for the blazing corona. While a Navy officer stood by with a stopwatch, Butler worked in 10- or 20-second blocks as he drew the outline of the corona, assessed the colors of the sky and Moon, and sketched the contours of the gaseous prominences that bloomed from the eclipse’s edge. Only then did he begin to paint.

In Butler’s painting of the 1918 eclipse, a corona of burnished orange encases the void of the blacked-out Sun, while the sky is mottled by gray-black clouds that recall the light effects of Frederic Edwin Church, Albert Bierstadt and other American landscape artists. It hangs here as part of a triptych of eclipse “portraits.” His painting of the solar eclipse of 1923, which Butler observed from California, includes a flash of yellow on the border of the black Sun: one of the so-called Baily’s beads, a phenomenon just before the totality when the disappearing Sun condenses into a single excrescence of blinding light. Two years later, in Connecticut, he saw another eclipse, this one resulting in especially long shafts of white that cut through the cloud cover. Those are the ectoplasmic wisps of the corona that scientists obsess over, and that more art-inclined observers may see as recalling the glowing halos of Renaissance painting.

 

 

Butler’s “Mars as Seen from Phobos.” Credit Princeton University Art Museum

 

In an age before photography could fully capture solar eclipses, Butler’s paintings were hailed as not just a personal impression but as a vital scholastic tool. In the mid-1920s he began to consult for the American Museum of Natural History in New York, and he designed a large astronomical wing whose construction was scuppered by the Depression. During this time Butler painted a number of otherworldly celestial scenes: our blue marble of a planet seen from the craggy lunar surface, or a vermilion Mars as viewed from its own two Moons. Here observation gives way to imagination—the surface of Deimos, the outer Martian satellite, appears as parched clay—but these too relied on models and calculations of atmosphere, shadow and light refraction.

He did allow himself one indulgence, though. At the bottom of “Mars as Seen From Phobos,” in the shadow of the red planet, is the outline of a human head. Presumably it’s the artist’s own, painting en plein air where there’s no air to speak of.

If you can’t make it to Princeton, check out the robust website devoted to “Transient Effects,” which features not only Butler’s beguiling paintings but also centuries of art, not on view at the museum, engaged with eclipses and the relationship between heaven and Earth. Long before Shakespeare set his eclipse upon Scotland, the Gospel of Luke described the lights going out after the death of Christ, and eclipses frequently appear in Crucifixion scenes by painters such as Matthias Grünewald (who may have seen an eclipse in 1502). Japanese printmakers used eclipses to heighten the spookiness of ghost scenes, while modern artists from Joseph Cornell to Roy Lichtenstein and Alma Thomas painted eclipses with both an awe for science and a freedom reserved for artists. They were, perhaps unwittingly, following in the tradition of Howard Russell Butler, for whom painting had a vocation as fundamental as the Sun.

[1] Jason Farago, “How Do You Paint an Eclipse? Work Fast in the Dark,” New York Times (Aug. 17, 2017). A version of this review appears in print on August 18, 2017, on Page C13 of the New York edition with the headline: “Celestial Brushwork”

The Illuminating Power of Eclipses

The Illuminating Power of Eclipses[1]

With the Sun obscured, eclipses can be revelatory: Starting at least over 2,000 years ago, they have been fodder for significant discoveries.

Hipparchus, the Greek astronomer and mathematician who lived more than 2,000 years ago, used the solar eclipse to solve a celestial geometry problem.

He knew that at a spot in northwestern Turkey an eclipse had totally blocked the Sun. But in Alexandria, about 600 miles away, only about four-fifths of the Sun had been covered. From that tidbit, he calculated the distance between the Earth and Moon to within roughly 20 percent of the correct figure.

Hipparchus was among the earliest scholars to take advantage of eclipses for science. In more recent centuries, scientists have used these celestial events as opportunities to study the Solar System, especially the Sun itself.

Usually, the Sun is too bright for scientists to see anything in its immediate vicinity. Only during eclipses does its radiant halo, the corona, become visible.

In 1605, the German astronomer Johannes Kepler mused that the corona observed during an eclipse might be a consequence of an atmosphere around the Moon scattering the passing Sunlight. (Eventually, scientists figured out that the corona surrounded the Sun, not the Moon.)

Observers also reported gigantic arcs rising out of the Sun, solar prominences now known to stretch hundreds of thousands of miles into space.

The invention of the spectroscope in the mid-19th century brought new solar discoveries. A glass prism splits light into a rainbow of colors emitted by specific atoms and molecules—bar codes, in a way, that identify the elements making the light.

In 1868, a French scientist, Pierre Janssen, traveled to India to view an eclipse through a spectroscope. The Sun’s prominences, he concluded, are largely made of hot hydrogen gas.

But a bright yellow line seen through the spectroscope, initially thought to be an identifier of sodium, did not match the wavelength of sodium.

That signified the discovery of helium, the universe’s second most common element. It would not be found on Earth for another 13 years.

During a total solar eclipse in 1869, two American scientists, Charles Augustus Young and William Harkness, independently observed an unexpected faint green line in the corona.

Scientists hypothesized it might be the emission of a new element, which was given the name coronium. It wasn’t until the 1930s that researchers realized coronium was not a new element, but rather iron with half of the atom’s 26 electrons stripped away.

That finding hinted at ultrahot temperatures on the Sun—and at a new mystery.

The lines of color seen on a spectrometer can also be used to measure temperature. The temperature of the surface of the Sun is about 10,000 degrees Fahrenheit.

Yet measurements of the corona, begun during a 1932 eclipse, put the temperature there much higher—millions of degrees. Ever since, solar scientists have been puzzling over precisely how the corona gets so hot.

Eclipses have taught scientists much about how our Solar System works. But the events have also brought down some firmly held ideas.

Astronomers long ago discovered that Mercury, the innermost planet, wobbled in its orbit more than Newton’s laws of motion indicated it ought to. In the 19th century, many thought there must be another little planet inside the orbit of Mercury that was pulling it around. They called it Vulcan.

Various observers reported seeing a small dot cross in front of the Sun, and many were convinced. “Vulcan exists, and its existence can no longer be denied or ignored,” The New York Times reported in September 1876.

During the darkness of a total solar eclipse two years later, two astronomers—one stationed in Wyoming, the other in Colorado—separately claimed to have spotted planets within the orbit of Mercury.

But they were wrong—they probably had seen well-known stars that become visible in the darkness of the eclipse. By the end of the century, most scientists doubted Vulcan was there, and in 1915, Einstein’s theory of general relativity provided a plausible explanation for Mercury’s wobble: a distortion in space-time caused by the Sun.

Einstein’s ideas set the stage for the most famous eclipse experiment of all time, in 1919, during which Sir Arthur Eddington observed the bending of starlight around the Sun. The findings verified the theory’s predictions.

Solar eclipses have been used not just to deduce what is going on in the Solar System but also to study Earth.

In 1695, the astronomer Edmund Halley discovered that modern calculations did not quite predict eclipses reported in ancient times. As it turned out, that is because the Earth’s spin has been slowing.

Credit Science & Society Picture Library/Getty Images

 

Chinese historical records provided clues needed to figure out how much. In the fourth century B.C., a Chinese philosopher, Mozi, wrote that “the Sun rose at night,” describing an epic battle that had occurred about 1,500 years earlier.

While paging through the text at the University of California, Los Angeles, a couple of decades ago, Kevin D. Pang, a former NASA scientist, realized this was not a poetic account of a fiery combat, but a description of a total eclipse.

The eclipse, which occurred close to sunset, indicated a passage into night, and the re-emergence of the Sun was thus a sunrise at night.

The day and place of the battle were known. Computer simulations determined how much slowing of Earth’s rotation rate was needed to make the shadow of an eclipse that occurred that day pass over the battlefield.

If the Earth was spinning faster back then, the day was shorter—by 0.07 of a second.

Eclipses also provide a test of weather models. “We’re not normally in a position to turn something off and see what the response is in a nice cause-and-effect sort of way,” said Giles Harrison, a professor of atmospheric physics at the University of Reading in England.

When the Sun disappears, temperatures drop and winds calm. Using weather station data from the 1900 eclipse that crossed North America, a meteorologist named H. H. Clayton noticed that the winds also appeared to change direction.

[1] Kenneth Chang, “The Illuminating Power of Eclipses,” New York Times (August 14, 2017).

Starmus Festival IV

Starmus Festival IV: Life And The Universe

The Starmus International Festival was held this year, June 18–23, 2017, in Trondheim, Norway. Starmus is an international gathering focused on celebrating astronomy, space exploration, music, art, and allied sciences such as biology and chemistry. It was founded by Garik Israelian, an astronomer at the Institute for Astrophysics in Tenerife, Canary Islands, Spain. The Festival has featured Buzz Aldrin, Neil Armstrong, Richard Dawkins, Stephen Hawking, Alexei Leonov, Jim Lovell, Brian May (English musiciaN), Jill Tarter, Kip Thorne, and Rick Wakeman among others. This year Brian Eno gave the keynote speach opening the Festival.

History

In 2007 Brian May, founding guitarist of the rock band Queen, completed his PhD dissertation, which was left unfinished in 1974 when Queen began to achieve significant success. May’s work focused on zodiacal dust in the Solar System. He had studied at Tenerife earlier through Imperial College in London, and resumed work there more than 30 years later. In 2007, his new advisor was Garik Israelian, and the two struck up a friendship, Israelian also being a musician. This led to the founding of the Starmus Festival—the name paying homage to stars and music—and the stage was set for the first Festival, which would occur four years later.

Concept

The festival has occurred in 2011, 2014 and 2016 in Tenerife, Spain. The fourth Starmus festival was held in Trondheim, Norway from June 18 to 23, 2017, under the title “Life And The Universe”.

The festival is described as an event where “the greatest minds in space exploration, astronomy, cosmology, and planetary science get together for a week of incredible talks, sharing of information, and appreciation of the knowledge we have of space and the universe.” This year there were enough brains and Brians to fill the multiverse

Brians Cox, Eno and May joined Stephen Hawking and Richard Dawkins in Tenerife to celebrate the synergy between astronomy and music, while astronaut Chris Hadfield, interviewed below, talked of our innate instinct to explore

In Starmus IV, gathered around the giant pool of the Mediterranean Palace hotel in Tenerife, hundreds of people focused on a familiar star. As pounding bass-filled music booms out of the PA, a great mass of the young, the middle-aged and the old are all glazed with submission as they appear to seek the meaning of the universe in the transformative process of ultraviolet radiation.

A few yards away in a darkened auditorium beneath a strange mock pinkish pyramid the Starmus festival was under way. Dedicated to celebrating a synthesis between astronomy and music that is of a more transcendent kind than that practiced around the Mediterranean Palace pool, it has drawn hundreds of people focused on very different but no less familiar stars: Brian Cox, Richard Dawkins, Brian May and, the greatest scientific supernova of them all, Stephen Hawking.

These, along with 11 Nobel laureates, were some of the leading speakers at the third Starmus festival at the Pirámide de Arona, an island of vaulting intellectual aspiration surrounded by tourist hotels with armies of sunbathers fastened to their poolside loungers as if by superglue.

Starmus is an unusual affair, but not necessarily for its setting. It’s not a typical science conference for academics at which new papers are presented. Nor is it a typical public talk designed to popularize established academic theories. Instead it’s a sort of hybrid—at once specialist and popularizing, openly public, and yet sufficiently off-circuit to feel discreetly private. It also seeks to bridge the separate worlds of science and the arts or, more specifically, music and cosmology.

The original idea was to do a concert at La Palma observatory, which features the world’s largest optical and infrared telescope. A disarming 53-year-old with a scattershot charm, Israelian had been working at NASA “trying to get acoustic sound waves in stellar atmospheres” and wondered if musicians might be able to use his collection. He approached Jean-Michel Jarre, who was keen on the idea, only for the concert to be cancelled when the Canary Islands government withdrew funding.

Undeterred, Israelian decided to commemorate the 50th anniversary of Yuri Gagarin’s first space flight with a festival in 2011. That was the first Starmus. In one sense it was a tremendous success because the keynote speaker was Neil Armstrong, the first man to walk on the moon and someone whose public appearances were so rare as to raise suspicion of their authenticity.

“When we announced Neil Armstrong was coming,” Israelian recalls, “we completely lost our credibility because no one believed he was going to be there. People said we were crazy. It was the worst thing we could do. And then he came!”

Armstrong’s fellow crew member Buzz Aldrin was also there, as well as Jim Lovell, commander of the ill-fated Apollo 13 who was played by Tom Hanks in the eponymous film. In addition there was the progressive electronic band Tangerine Dream.

However, in financial terms it was a disaster. Admission was free for most visitors, there was no sponsorship, and Israelian and his co-producers were left to pick up a hefty bill. But that didn’t stop them holding a second Starmus, again on Tenerife. This time Stephen Hawking came. He was a massive draw, but once again the festival lost money. Israelian talks darkly of broken promises by the Canary Islands government and the disappointing lack of sponsorship.

They say that one definition of madness is to keep doing the same thing and to expect different results. If so, then Israelian is mad in the best tradition of mad professors, because he came back for a third time with a cast list that was starrier than ever.

Not until you’ve seen Brian Cox at a gathering of science buffs can you appreciate how much the awe-filled physicist and TV personality is adored by his public. To walk alongside him though the Pirámide de Arona is to be submerged by a sea of autograph hunters and selfie-takers. Unlike Dawkins, who looks as if he can’t wait to get to the green room, Cox seems to relish the attention. What did he think of his first Starmus?

“It’s brilliant,” he says, tucking into an ice-cream. “There’s a lot of time to talk to the speakers. And you don’t normally get people like Brian Eno, Brian May and Hans Zimmer in the same room as Stephen Hawking and Joe Stiglitz.”

Starmus IV featured a lecture by Brian Eno. Eno’s discussed the intimate relationship between science and art, one the legendary music producer and former Roxy Music synthesizer player characterized as “science discovers and art digests”.

“He’s right,” says Cox. “If you look at the history of astronomy, these ideas of finding our place in the universe have had a massive social impact. The obvious one is the relegation of the Earth from the centre of it. That battle to define whether or not we’re special was one of the defining battles of the 17th century onward. Our physical demotion is now widely accepted, but what of the emotional impact if you start talking as Brian Greene and Martin Rees [two other speakers] did about the multiverse. What does it mean if there are an infinite number of these pocket universes? If that’s the case, we’re not geographically significant. We’re not even lucky. We’re just inevitable. Does that matter?”

Good question, but I’m not sure that I’ve fully mastered the concept of an infinite number of pocket universes, so I silently nod with as much sagacity as I can muster.

“The fact that we’re in an insignificant physical speck in a possibly infinite universe,” he continues, “is as easy or difficult to accept as that we are a very tiny temporal speck in a possibly infinite time span. We know how to deal with that, with death and a finite life time. There is an interesting parallel to be drawn. But it’s a conversation that won’t be had by physicists. It’s a conversation that’s best had in art, philosophy, literature and theology. That’s where the meaning of the things we discover about the universe is teased out.”

Israelian was asked if the lack of diversity was an issue for him. “No, no. I don’t think about such things,” he said, irritated by the question. “I invited many female scientists and they couldn’t come. I’ve got limited time—I cannot keep inviting people to get 50%. That’s not my problem.”

The round table debate turned out to be quite dull, with everyone speaking in optimistic platitudes or pessimistic generalities. It’s not a forum for deep expertise but strong opinion and it turns out that in a group debate the sum is less than its parts.

The debate is streamed live on the internet and also into the auditorium beneath the pyramid in Tenerife, which is about half full. The crowd at Starmus is much younger on average than the speakers and, in terms of gender at least, much more representative of the outside world.

A 40-year-old physics student, Raquel Rodriguez, was interviewed. If you were looking for a stereotype of an astro-nerd, then Rodriguez is not where you’d start. She looks like Sharon Stone in Basic Instinct and said her favorite area of discussion is “dark matter and quantum physics”.

Then there’s a 32-year-old Norwegian nurse called Guro Nygård. Her brother brought her for the week as a birthday present. She’s fascinated by astronomy, she says, though this is the first time she’s been to such an event. Her personal highlight from the week was seeing Hawking. “He’s unbelievable,” she says. “His personal history is truly amazing.”

Both women noticed the imbalance between men and women but both believed the key thing was to get the best people and that gender, in the short term, was a secondary issue.

Thirty-six-year-old Sam Alexandroni was talking to a neuroscientist, a brain surgeon and a rocket sci-entist. He used to be a journalist at the New Statesman, he said, but now he’s writing a novel. “My teachers did a miserable job at school of communicating the wonder of science. Having discovered it later in life, events like this are brilliant for communicating ideas,” he says. As for combining the sciences and the arts, Alexandroni is all for it, though he says he’s “yet to experience the synergy” at Starmus.

Starmus IV highlighted moonwalkers and women scientists.

Tiny World Beyond Pluto

Chasing Shadows for a Glimpse of a Tiny World Beyond Pluto[1]

An artist’s rendering of one possible version of the Kuiper belt object 2014 MU69, the next flyby target for NASA’s New Horizons mission. Credit Alex Parker/NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

 

 

 

 

 

 

This summer [2017], scientists crisscrossed two oceans, braved wind and cold and deployed two dozen telescopes—all for five blinks of starlight that lasted a second or less.

For the team working with NASA’s New Horizons spacecraft, which made a spectacular flyby of Pluto two years ago, those smidgens of data provide intriguing hints about the spacecraft’s next destination, a distant frozen world that is believed to be a pristine, undisturbed fragment from the earliest days of the solar system.

New Horizons will fly past it on Jan. 1, 2019.

But the object is so far away—a billion miles beyond Pluto—and so small—no more than 20 miles wide—that almost nothing was known about it.

From the five blinks, obtained with exhausting effort, scientists now know that it has an odd shape.

Instead of round like a ball it appears to be more like a long, skinny potato—or maybe two objects in close orbit around each other, possibly even touching.

“It’s like, wow, this is going to be really cool,” said Marc W. Buie, an astronomer at the Southwest Research Institute in Boulder, Colo., who led the observations. “We don’t know what we’re going to find.”

While Pluto is the biggest object in the ring of icy debris beyond Neptune known as the Kuiper belt, this object with the designation 2014 MU69 is among the smallest. It orbits more than four billion miles from the Sun, and it is like a time capsule, promising clues about how the planets formed.

Astronomers using the Hubble Space Telescope first spied it three years ago as they searched for somewhere for New Horizons to visit after Pluto.

All Hubble could see was a slowly moving speck of light—enough to calculate an orbit and determine that New Horizons could reach it. But almost everything else about MU69 was a mystery or a guess. Not even the largest, most powerful telescopes on Earth can see it at all.

The New Horizons scientists could, however, learn more about it during a few chance moments when a star in the night sky momentarily vanished because MU69 passed in front of it.

From the distance to MU69, its speed and how long the star winks out, astronomers can calculate the width of the object.

It turned out that a bonanza of three such events, which are known as occultations, were expected to occur within a two-month period this year [2017], on June 3, July 10 and July 17, as MU69 passed in front of three different stars.

“That’s just crazy,” Dr. Buie said. “That’s just how the dice rolled on this one.”

But they did not have the data—sufficiently precise star locations—to know exactly where to set up telescopes to observe the events.

“We say it’s hard, and it is,” Dr. Buie said. “If you’re not in the shadow, you don’t see it. Even a year ago, this would have been categorically impossible.”

But they were lucky again because a European Space Agency mission called Gaia was methodically mapping more than a billion stars in the Milky Way galaxy. New Horizons scientists got an early look at the catalog in late April.

Dr. Buie had been scrambling to gather equipment and observers, and on June 3, 50 team members turned 24 telescopes on two continents, in Argentina and South Africa, to the sky.

One of the telescopes that tried to observe the occultation of the object on June 3 from South Africa. This attempt failed, but scientists succeeded in July from Argentina. Credit Henry Throop, via NASA, Johns Hopkins Applied Physics Laboratory and Southwest Research Institute

The telescopes took more than 100,000 images of the star, waiting for MU69 to pass in front of it.

But the star never vanished. The scientists had completely missed the shadow.

“I was physically and emotionally exhausted, psychically damaged,” Dr. Buie said.

In late June and early July, Hubble made additional observations of MU69 that refined the orbit.

The July 10 [2017] occultation track mostly passed over the southern Pacific. This time, the New Horizons scientists took off from Christchurch, New Zealand, in Sofia, a NASA 747 equipped with an 8.2-foot-diameter telescope. They headed north, toward Fiji, to intercept the shadow and returned 10 hours later.

Again, the star never disappeared. They had missed the opportunity again.

They immediately headed back to Argentina for one more try.

  1. Alan Stern, the principal investigator of New Horizons, said he was confident, with the additional Hubble measurements, that they would capture the vanishing of a star this time. But mission managers also always worry about the so-called unknown unknowns. Perhaps something unanticipated in the Hubble data was deceiving them about MU69’s position.

The July 17 shadow was predicted to pass over Comodoro Rivadavia, a city along the Atlantic coast of South America. Comodoro’s nickname is “the capital of wind.” In the middle of winter, the weather was also cold.

“It was a pretty intense event,” Dr. Stern said. “Your telescopes were shaking.”

At several observing sites, tractor-trailer trucks served as windbreaks, as did contraptions made of poles and canvas.

A highway was shut for a couple of hours so that the headlights of cars and trucks would not spoil the observations.

The skies were clear, and the time of the shadow, 12:50 a.m., passed.

A few hours later, Amanda M. Zangari, one of the Southwest Research Institute scientists on the New Horizons team, was staring blearily at her laptop analyzing the data from one of the telescopes.

In her exhaustion, the data was not making sense to her. Then it hit her. “I realized it didn’t make any sense, because the occultation star was missing,” she said.

This is what she saw:

To learn more about Kuiper belt object 2014 MU69, astronomers focused on the star at the center. When MU69 passed in front of it, it blocked out the starlight for less than half a second. The time difference between frames is 0.2 seconds. NASA/JHUAPL/SwRI

Five telescopes, it turned out, had detected the star’s vanishing for up to about a second.

The success also confirmed that the Sofia observations a week earlier had barely missed the occultation and were close enough to the shadow to be useful. Preliminary analysis found no signs of dimming, indicating there are no clouds of debris in the neighborhood of MU69 that could imperil New Horizons.

The five blinks established the odd shape. If it is one skinny potato, MU69 is no more than 20 miles long. If it is two spheres circling each other, each is about nine to 12 miles wide.

Many Kuiper belt objects in this region are binaries, although most are considerably larger than MU69. If one this small can be a binary, that may change the understanding of how Kuiper belt objects formed.

Mission managers can still tweak the flyby time of the New Horizons spacecraft by a couple of hours. Ideally, they want to view the broad side of MU69 and optimize geometry of tracking stations on Earth during the flyby.

“We’re working through all those mathematical issues,” Dr. Stern said.

Another occultation is possible in August next year [2018]. The scientists have not decided whether they will chase the shadow one more time.

[1] See Kenneth Chang, New York Times (August 8, 2017). A version of this article appears in print on August 10, 2017, on Page A14 of the New York edition with the headline: Chasing Shadows of a Tiny World Beyond Pluto.

History of Solar Eclipses

History of Solar Eclipses[1]

Ugarit Eclipse (1223 B.C.E.)

The oldest known record of a total solar eclipse may be a cuneiform tablet from Ugarit. Mesopotamian historians in Ugarit, a port city in Northern Syria, recount that the Sun was “put to shame” during this total eclipse.

Then, a report in the journal Nature in 1989 suggested, in fact, the eclipse actually occurred on March 5, 1223 B.C. That new date was based on an historical dating of the tablet as well as an analysis of the tablet’s text, which mentions the visibility of the planet Mars during the eclipse.

The presence of Mars in the sky helped astronomers fix the date. Even without the detailed orbits of Earth and Moon, Babylonians predicted lunar eclipses by observing the event’s natural periodicity. Solar eclipses stumped them, probably because they occurred less frequently and their narrow shadows are less widely visible.

 

 

Antitkythera Mechanism (2nd Century, B.C.E.)

A ship sinks off the coast of Antikythera, bearing a palm-size bronze mechanism used to calculate the positions of the Sun, Moon, and planets, and the timing of the Olympiads–and used to predict lunar and solar eclipses. Divers recovered the device during an expedition in 1900 and 1901. According to the historian, Herodotus, Thales of Miletus predicted a solar eclipse in 585 B.C.E., but modern historians are skeptica

 

Aztec Calendar (1325 C.E.)

The Sun Stone, Stone of the Five Eras, or sometimes (erroneously) called Aztec calendar stone is a late post-classic Mexican sculpture housed in the National Anthropology Museum in Mexico City, and is perhaps the most famous work of Aztec sculpture.

Shortly after the Spanish conquest, the monolithic sculpture was buried in the Zócalo, the main square of Mexico City. It was rediscovered on December 17, 1790 during repairs on the Mexico City Cathedral. Following its rediscovery, the calendar stone was mounted on an exterior wall of the Cathedral, where it remained until 1885. Most scholars think that the stone was carved some time between 1502 and 1521, though some believe that it is several decades older than that.

The calendar is found in the year of a 99 percent solar eclispe. The Aztecs recorded many eclipses, often those connected to cultural or political events. A 260-day Aztec calendar stone may depict the death of the Sun god Tonatiuh at the hands of an eclipse monster, whose claws clutch at human hearts, according to Susan Milbrath, emeritus curator at the Florida Museum of Natural History.

 

 

Ming Dynasty Imperial Calendar (1384)

The Ming dynasty in China officially adopted the Imperial Calendar, which included predictions for solar and lunar eclipses. Chinese astronomers had been predicting eclipses by the third century C.E. By the fifth century C.E., they were accurate to within three hours and by the 12th century C.E. were spot on. Many of the solar eclipses they predicted didn’t happen, possibly, some historians think, because the consequences for failing to warn of a solar eclipse far outweighed the consequences of false positives.

 

 

 

 

Erhard Weigel’s Map [1654]

The German astronomer, Erhard Weigel, made the first map of the shadow path of a solar eclipse before the event itself. Weigel’s map had the shadow on a straight-line path; in fact, it made an arc across the top of Scotland and Denmark and southward to what is now Iran and India. The circles represent the shadow of the moon (penumbra) and the path of the total solar eclipse is the line annotated as “Via Umbra Luna”. A curious feature of this map is that the path of the eclipse is shown as a straight line instead of the sweeping arc which results from the combined motion of the Moon’s shadow and the Earth’s rotation about a tilted axis. This map can be best understood as a snapshot of the view of the Earth during the middle of eclipse. While it’s difficult to judge whether the greater error is in the geographic positions of continents or in the eclipse calculations, Weigel’s map is a credible depiction of this total solar eclipse.

While Weigel’s was the first such printed map ever produced. This honor is usually falsely accredited to Edmund Halley for his 1715 eclipse map.

 

Edmund Halley, Path and Timing of Solar Eclipse (1715)

Edmond Halley, the astronomer who forecast the return of the comet that now bears his name, predicted the path and timing of a 1715 solar eclipse, from the southwest of England to the northeast, running straight over London. He published engravings of his map in part to warn citizens to keep calm and to solicit help in recording how log the totality of the eclipse lasts. Two dozen people responded. These citizen-science observations helped him refine his model and improve his predictions.

Wikipedia will tell you that this is known as Halley’s Eclipse, after Edmond Halley, who produced accurate predictions of its timing and an easily-read map of the eclipse’s path. Halley did not live to see the confirmation of his predictions of a returning comet–a 1759 triumph for the Newtonian system–but he was able to enjoy his 1715 calculations, which were within 4 minutes, and to improve on them with a corrected map (above). He observed the eclipse from the Royal Society’s building in Crane Court on a morning with a sky of “perfect serene azure blew”.

Halley, however, also used his map to inform the less knowledgeable, and to trumpet the successes of natural philosophy:

    The like Eclipse having not for many ages been seen in the Southern Parts of Great Britain, I thought it not improper to give the Publick an Account thereof, that the sudden darkness, wherein the Starrs will be visible about the Sun, may give no surprize to the People, who would, if unadvertized, be apt to look upon it as Ominous, and to interpret it as portending evill to our Sovereign Lord King George and his Government, which God preserve. Hereby they will see that there is nothing in it more than Natural, and no more than the necessary result of the Motions of the Sun and Moon; And how well those are understood will appear by this Eclipse.

 

 

 

Baily’s Beads (1836)

The English astronomer, Francis Baily, traveled to Jedburgh, Scotland, to observe a total solar eclipse and noted that, as the Sun disappears, a strong of irregularly sized and randomly spaced lights shine in an arc connecting the tips of the Sun’s crescent. The effect, now known as Baily’s beads, occurs when sunlight shines through the valleys of the Moon.

Warren de la Rue Photographed 1842 Eclipse

Warren de la Rue, an English inventor, made the most ambitious attempt to photograph an eclipse since photographers started chasing the phenomenon in 1842. He led an expedition to Rivabellosa, in northern Spain, hauling a telescope and glass plates through the mountains and setting up a darkroom under a canvas tent.

Pierre Janssen (1868)

The French astronomer Pierre Janssen used a newfangled instrument, a spectroscope, to observe a total eclipse in Guntur, India. The spectroscope, by breaking light from the Sun down into its component colors, gave Janssen clues as to the chemical composition of the Sun’s atmosphere. A yellow band of light betrayed the existence of a new element, helium.

“Two splendid protuberances appeared—one of them … shone of a splendour which is difficult to imagine,” said Pierre Janssen after looking at the solar eclipse of 1868 through his rudimentary spectroscope. He, along with several other astronomers on the Indian expedition, had stumbled across the D3 line. Unremarkable to the naked eye, this solitary spectral signature was, in fact, the solar fingerprint for helium. Helium would not be found on Earth for another 27 years.

The graphic below is a photograph of the Sun’s surface (left) that was taken by Janssen (shown to the right). From helium to relativity, eclipses have a history of producing big finds

Total Eclipse Crosses North America (1878)

A total eclipse, much anticipated in the press, crossed North America from Alaska to Louisiana. During the blackout, the astronomer James Watson claimed to have spotted a new inner planet, Vulcan, that had been the target of hunts by amateurs and professionals. The proposed planet would explain why Mercury seemed to deviate from Newton’s laws of motion. Later, Einstein explained Mercury’s behavior with his theory of general relativity.

Mendeleev First to Attempt to view Eclipse from the Air (1887)

Mostly known in the West for creating the Periodic Table of Elements, Dmitry Mendeleev’s contribution to science is huge. A real Renaissance man, his areas of study ranged from chemistry to aeronautics to Arctic exploration to demographics.

Mendeleev’s greatest contribution to science is certainly the Periodic Table of Elements, which says the properties of basic elements repeat periodically when they are arranged by their atomic number. He made the discovery in 1869 during his work on a textbook on chemistry basics. The first edition of the book published a year later had the periodic table in it. Mendeleev’s further study resulted in prediction of the properties of elements that had not yet discovered at the time, like gallium or germanium.

A good example of Mendeleev’s lifestyle as a field researcher rather than a “bookworm professor” was his balloon flight in 1887. The hydrogen-filled balloon was meant to lift the scientist high enough to have unobstructed view of a solar eclipse, a rare chance to study the solar corona. However the day of the event was rainy, the balloon got wet and too heavy to lift both the pilot and the scientist.

Scientifically the trip was in vain, the aerostat failing to rise over the clouds, but it was a success as a publicity stunt. The dramatic story of a famous scientist risking his life and forced to make repairs during his first ballooning experience was so daring that the French aerostat meteorology academy awarded him a medal for it. It is worth mentioning that meteorology was among the many areas of interest for Mendeleev.

 

 

 

Refined Calculations of the Moon’s Diameter (1925)

Eclipse watchers took to rooftops one Saturday morning in Upper Manhattan in anticipation of an eclipse. Astronomers knew that Harlem would see totality but Times Square would not. Exactly where the dividing line would fall was unknown. Observers set up along Riverside Drive to watch for the shadow’s edge. An onlooker at Riverside Drive near 96th Street saw totality briefly, but another at Riverside and 85th Street did not. The experiment allowed17 Man astronomers to refine their calculations of the Moon’s diameter.

[1] Suggested by an article by Katie Peek, “A Brief Celestial History.” In New York Times Magazine (August 6, 2017, p. 5)

The Universe in Motion

The Universe in Motion[1]

The mathematics section of the National Academy of Sciences lists 104 members. Just four are women. As recently as June, that number was six.

Marina Ratner and Maryam Mirzakhani could not have been more different, in personality and in background. Dr. Ratner was a Soviet Union-born Jew who ended up at the University of California, Berkeley, by way of Israel. She had a heart attack at 78 at her home in early July, 2017.

Success came relatively late in her career, in her 50s, when she produced her most famous results, known as Ratner’s Theorems. They turned out to be surprisingly and broadly applicable, with many elegant uses.

In the early 1990s, when Amie Wilkinson was a graduate student at Berkeley, a professor tried to persuade Dr. Ratner to be her thesis adviser. She wouldn’t consider it: She believed that, years earlier, she had failed her first and only doctoral student and didn’t want another.

Dr. Mirzakhani was a young superstar from Iran who worked nearby at Stanford University. Just 40 when she died of cancer in July, she was the first woman to receive the prestigious Fields Medal.

[Image left: Marina Ratner in Moscow in 1991. Credit via Anna Ratner; Image right: Maryam Mirzakhani in 2014, the year she won the Fields Medal. Credit Seoul ICM 2014, via Agence France-Presse—Getty Images]

 

Amie Wilkinson first heard about Dr. Mirzakhani when, as a graduate student, she proved a new formula describing the curves on certain abstract surfaces, an insight that turned out to have profound consequences—offering, for example, a new proof of a famous conjecture in physics about quantum gravity.

Wilkinson was inspired by both women and their patient assaults on deeply difficult problems. Their work was closely related and is connected to some of the oldest questions in mathematics.

The ancient Greeks were fascinated by the Platonic solid—a three-dimensional shape that can be constructed by gluing together identical flat pieces in a uniform fashion. The pieces must be regular polygons, with all sides the same length and all angles equal. For example, a cube is a Platonic solid made of six squares.

Early philosophers wondered how many Platonic solids there were. The definition appears to allow for infinite possibilities, yet, remarkably, there are only five such solids, a fact whose proof is credited to the early Greek mathematician Theaetetus. The paring of the seemingly limitless to a finite number is a case of what mathematicians call rigidity.

Something that is rigid cannot be deformed or bent without destroying its essential nature. Like Platonic solids, rigid objects are typically rare, and sometimes theoretical objects can be so rigid they don’t exist—mathematical unicorns.

In common usage, rigidity connotes inflexibility, usually negatively. Diamonds, however, owe their strength to the rigidity of their molecular structure. Controlled rigidity—that is, flexing only along certain directions—allows suspension bridges to survive high winds.

Dr. Ratner and Dr. Mirzakhani were experts in this more subtle form of rigidity. They worked to characterize shapes preserved by motions of space.

One example is a mathematical model called the Koch snowflake, which displays a repeating pattern of triangles along its edges. The edge of this snowflake will look the same at whatever scale it is viewed.

The snowflake is fundamentally unchanged by rescaling; other mathematical objects remain the same under different types of motions. The shape of a ball, for example, is not changed when it is spun.

[A Koch snowflake. via Wikimedia Commons]

Dr. Ratner and Dr. Mirzakhani studied shapes that are preserved under more sophisticated types of motions, and in higher dimensional spaces.

In Dr. Ratner’s case, that motion was of a shearing type, similar to a strong wind high in the atmosphere. Dr. Mirzakhani, with Wilkinson’s colleague Alex Eskin, focused on shearing, stretching and compressing.

These mathematicians proved that the only possible preserved shapes in this case are, unlike the snowflake, very regular and smooth, like the surface of a ball.

The consequences are far-reaching: Dr. Ratner’s results yielded a tool that researchers have turned to a wide variety of uses, like illumining properties in sequences of numbers and describing the essential building blocks in algebraic geometry.

The work of Dr. Mirzakhani and Dr. Eskin has similarly been called the “magic wand theorem” for its multitude of uses, including an application to something called the wind-tree model.

More than a century ago, physicists attempting to describe the process of diffusion imagined an infinite forest of regularly spaced identical and rectangular trees. The wind blows through this bizarre forest, bouncing off the trees as light reflects off a mirror.

Dr. Mirzakhani and Dr. Eskin did not themselves explore the wind-tree model, but other mathematicians used their magic wand theorem to prove that a broad universality exists in these forests: Once the number of sides to each tree is fixed, the wind will explore the forest at the same fundamental rate, regardless of the actual shape of the tree.

There are other talented women exploring fundamental questions like these, but why are there not more? In 2015, women accounted for only 14 percent of the tenured positions in Ph.D.-granting math departments in the United States. That is up from 9 percent two decades earlier.

Dr. Ratner’s theorems are some of the most important in the past half-century, but she never quite received the recognition she deserved. That is partly because her best work came late in her career, and partly because of how she worked—always alone, without collaborators or graduate students to spread her reputation.

Berkeley did not even put out a news release when she died.

By contrast, Dr. Mirzakhani’s work, two decades later, was immediately recognized and acclaimed. Word of her death spread quickly—it was front-page news in Iran. Perhaps that is a sign of progress.

Wilkinson first met Dr. Mirzakhani in 2004. She was finishing her Ph.D. at Harvard, and Wilkinson was a professor at Northwestern, pregnant with her second child.

Given her reputation, I expected to meet a fearless warrior with a single-minded focus. Wilkinson was quite disarmed when the conversation turned to being a mathematician and a mother.

“How do you do it?” she asked. That such a mind could be preoccupied with such a question points, Wilkinson thinks, to the obstacles women still face in climbing to math’s upper echelons.

At Harvard, the number of tenured women research mathematicians is currently zero. At Wilkinson’s institution, the University of Chicago, until 2011 only one woman had ever held such a position.

Women are only gradually joining the ranks, in what might be called a “trickle up” fashion.

Students often tell Wilkiknson that her presence on the faculty convinces them that women belong in mathematics. Though she would have shrugged it off, Wilkinson was similarly inspired by Dr. Ratner.

Wilkinson hopes she played this role for Dr. Mirzakhani. And for all of her reticence about being famous, Dr. Mirzakhani has inspired an entire generation of younger women.

There are a surprising number of social pressures against becoming a mathematician. When you’re in the minority, it takes extra strength and toughness to persist. Dr. Ratner and Dr. Mirzakhani had both.

For the inspiration they provide, but above all for the beauty of their mathematics, we celebrate their lives.

[1] Amie Wilkinson, “With Snowflakes and Unicorns, Marina Ratner and Maryam Mirzakhani Explored a Universe in Motion,” New York Times (August 7, 2017). Marina Ratner, émigré mathematician died at 78. Her death was reported in the New York Times, July 25, 2017. Amie Wilkinson is a professor of mathematics at the University of Chicago. A version of this article appears in print on August 8, 2017, on Page D1 of the New York edition with the headline: The Universe in Motion.