Eclipse Excerpt 3 of 6

In anticipation of Monday’s total eclipse, this week we’ve got a series of excerpts from the Svalbard chapter of Out in the Cold, in which we traveled up to 800 miles from the North Pole in search of totality in March, 2015. Get a copy of the whole book for yourself, or order the unabridged audiobook.

FIGURING OUT ECLIPSES

Besides being tiny bits of land surrounded by oceans, Svalbard and the west African island of Principe share vanishingly little, but just like the Solar Wind Sherpas are doing on Svalbard this week, a hardy team of British scientists set out a hundred years ago to made eclipse history on Principe.

On 8 March, 1919 Sir Arthur Stanley Eddington and his party sailed from Liverpool bound for the equator, and just north of there, on 23 April, landed in the Gulf of Guinea on a small, humid, buggy island around a hundred twenty miles west of the African coast.

Albert Einstein’s audacious 1915 theory of general relativity sorely needed testing. If it were proven right it would mean that space and time are pliable as the surface of a trampoline, twisting and bending all over the place.

Relativity predicted that light need not always travel straight, but rather should warp as it passes the gravitational field of an object in space, like the sun. But how to measure such a thing?

If light from stars behind the sun were bent by the sun’s gravitational field, those stars’ apparent position might be distorted so that they became visible. Their apparent position should be different from their position in the sky at night, when the sun is far away on the other side of the Earth.

But how to see behind the blinding light of the sun? Perhaps with the help of the moon, during an eclipse.

Two years after publication of Einstein’s theory, the British Astronomer Royal Sir Frank Watson Dyson worked out that during the eclipse of 29 May, 1919, the sun would cross the Hyades, a cluster of stars near enough that there would be a number of stars bright enough to see through a telescope, and that the island of Principe would be a fine place to watch it.

Dyson sent Eddington to test Einstein’s theory.

•••••

Scientific cooperation between countries waxes and wanes as surely as celestial bodies. Freed from Soviet restrictions, in the 1990s Russian scientists rushed to collaborate with their counterparts, eager to compare their science with the West. Some of that collegiality has since lessened.

Similarly, by 1919 the Great War had severed lines of scientific communication. A Russian mathematician knew of Einstein’s work but couldn’t participate from behind the walls of a German prison. A German astronomer couldn’t test the theory from his perch at a Russian prison camp. A naval blockade kept German scientific journals from crossing the English Channel. To Eddington that was plain wrong.

Eddington learned of Einstein’s work through a middleman mathematician in neutral Holland, whom Einstein could visit.

A British scientist’s aggressive work on the theories of a German physicist kicked up controversy, especially as Eddington, a Quaker, claimed conscientious objector status and needed the help of Dyson, his boss the Astronomer Royal, to stay out of jail. Packing Eddington off to do science on a remote island for several months was just the thing.

•••••

Eddington: “The baggage was brought … mainly by tram, but with a break of about a kilometer, where it had to be transported through the wood by native carriers.”

The party set up their viewing station at latitude one degree forty minutes north, using “freely” the “ample resources of labour and material” available locally.

Eddington noted that “Near the center” of this tiny six-by-ten mile island, “mountains rise to a height of 2,500 feet, which generally attract heavy masses of cloud.”

And so they did. “The days preceding the eclipse were very cloudy. On the morning of May 29 (eclipse day) there was a very heavy thunderstorm….”

But “about half-an-hour before totality the crescent sun (partial eclipse) was glimpsed occasionally.”

It would have been an awfully long trip to have come back empty, but in the end “16 (photographic) plates were obtained … by moving a cardboard screen unconnected with the instrument.”

Eddington compared a set of “true” positions of the stars – photos he had taken of the same patch of sky when the sun was nowhere around – with the set of photos he took during the eclipse. He could confirm Einstein’s theory.

•••••

The day after Eddington announced his findings, the New York Times of 10 November, 1919, ran these headlines:

LIGHTS ALL ASKEW IN THE HEAVENS

Men of Science More or Less

Agog Over Results of Eclipse

Observations.

__________

EINSTEIN THEORY TRIUMPHS

__________

Stars Not Where They Seemed

or Were Calculated to be,

but Nobody Need Worry.

•••••

Politics will forever hover over science. But in this case, right in the middle of the Great War, Arthur Eddington brought down barriers to advance the scientific standard, to explain Einstein’s theory and to spark the imagination of an otherwise war-distracted public.

As a bonus, the Eddington team saw the largest solar prominence to be seen at a total eclipse since. It extended some 100,000 kilometers beyond the surface of the sun.

Eclipse Excerpt 2 of 6

In anticipation of Monday’s total eclipse, this week we’ve got a series of excerpts from the Svalbard chapter of Out in the Cold, in which we traveled up to 800 miles from the North Pole in search of totality in March, 2015. Get a copy of the whole book for yourself, or order the unabridged audiobook.

MYTH

A great chariot carried the sun across the ancient Norse sky, and two wolves gave chase. Suppose they caught it? Some said that was when an eclipse occurred. In old French and German there are expressions like “God protect the moon from wolves.”

To Transylvanians, human failing caused the sun to shudder and turn away in disgust, covering herself with darkness. Putrid fogs gathered, poisonous dew fell from the sky and ghosts swarmed the earth. After an eclipse water and produce were thought contaminated and unsafe, even for livestock. The poisonous dew might bring plague.

Native Alaskans too believed eclipses sent something vile descending to earth. Whatever it was could cause sickness if it settled on cooking tools so women turned over their pots and hid the spoons underneath.

Into the nineteenth century humans would huddle indoors. If they had to go out they would cover their mouths and noses. All across the Carpathian mountains the more superstitious would even destroy clothing they’d left drying outdoors.

In the Faroe Islands 1954 eclipse “a woman named Erla Kirstin Viberg recalled her mother telling her to bring in the sheets from the clothesline so that they wouldn’t burn. ‘People were talking about total destruction,’” wrote Lavinia Greenlaw in The New Yorker.

Since they were accustomed to the sun disappearing for long stretches during the winter, it’s hard to say just how alarmed northern people became at the loss of the sun, but elsewhere people clanged and pounded on pots and pans, screamed, shouted and cried out to scare away whatever evil spirit had descended. The Chippewa shot fiery arrows into the sky hoping to rekindle the sun.

And whoever they were and whatever they did, in time the people were always successful. The demon always left the sun.

•••••

An often quoted statistic by laymen like we in Longyearbyen is the wonder-filled fact that total eclipses are possible only because the sun’s diameter is about 400 times that of the moon, while the moon is about 400 times closer to earth, allowing for the moon’s disk to just cover the sun’s. Consider the serendipity.

Further, we just happen to be here at the right moment in the cosmos.  The moon’s orbit drifts about four centimeters a year away from earth. Scientists have measured its retreat using tools left on the moon by the Apollo program. A billion years ago all eclipses entirely blotted out the sun, and in just fifty million years the moon will be too small when viewed from Earth to ever cover the sun. Even now it barely does. If the moon’s diameter were just 169 miles smaller total eclipses would be impossible.

•••••

Suppose that next Tuesday you wake up on the equator. Swinging in a hammock on the beach and turning with the earth, you will travel 24,901 miles that day, not counting the swinging.

Pull your calculator from your bathing suit, divide 24,901 by the length of a day, 23 hours, 56 minutes and four seconds, and you find that you and your hammock have been traveling 1,040 miles per hour.

Up here, more than the beachwear is different. At Longyearbyen the Earth’s circumference is just 5,101 miles. At 78 degrees north the Earth turns at a leisurely 215 miles per hour. The Central European time zone at Svalbard stretches just 212 miles. With the fastest car and a good road you could just about drive across the time zone before an hour was up and go back in time.

•••••

A legendary Welsh shepherd named Guto Nyth Bran was so fast that he could blow out a candle and be tucked into bed before the light faded. Like the shadow of the moon, he traveled faster than the fastest commercial jet. Except the Concorde.

The speed of the moon’s umbral shadow – the thing that causes totality – varies with the latitude at which it crosses Earth. It can move as slowly as 1,710 kilometers per hour, and Concorde’s maximum cruising speed was 2,200 kilometers per hour, which got scientists thinking. In 1973 a team aboard Corcorde flight 001 chased the moon’s shadow for an incredible 74 minutes of totality across Africa, besting by nearly ten times the maximum earthbound length of totality, which is about 7-1/2 minutes.

The Concorde didn’t go into passenger service until 1976, but in 1973 was in in-flight testing. Packed with gear from a British team headed by Dr. John Beckman with the Astrophysics Group at Queen Mary College, London, flight number 001 rose into the air for a rendezvous.

The pilot, André Turcat, and a crew of four were joined by seven astronomers, two assistants and a photographer for a mach 2.05, hour and fourteen minute totality like no other.

•••••

At the beginning of each lunar month we call the moon “new.” The sun, moon and Earth line up like you did in grade school, one behind the other. Out in space this happens every 29.5 days. Here on Earth the Gregorian calendar rules the business and legal world but the rhythm of the moon regulates more soulful realms like the Chinese and Vietnamese New Years, the Hindu Diwali festival, and the Islamic holy month of Ramadan.

At new moon the moon is between the Earth and the sun, so the sun shines on the side of the moon facing away from the Earth, and the moon is invisible to us, beginning its monthly cycle. The scientific word for this is syzygy, more a word I might connect with human reproduction, or questionable hygiene.

Eclipses occur in clusters. A bit of celestial mechanics shows why. The orbit of the moon is tilted about five degrees from the Earth’s orbit around the sun, so the plane of the moon’s path crosses the Earth’s twice a year on opposite sides of its orbit (called nodes), once ascending and once descending, in intervals of 30 to 37 days. This is when you see eclipses.

(Worthy digression: The moon doesn’t really orbit the Earth. They centrifugally pull each other around a common center of gravity roughly 3000 miles from the Earth’s center).

The orbits of the sun, Earth and moon don’t all sync up, so the sun crosses one of the moon’s nodes and returns to it every 346.62 days, not quite a year. As a result eclipse “seasons” march slightly backward across our Gregorian calendar, as does Ramadan, calculated by the 354 day lunar calendar.

Either the Chaldeans of Babylon were incredibly smart people, or there wasn’t much to do in Mesopotamia hundreds of years BCE. Studying the heavens, the Chaldeans determined that every 6,585.3 days the yearly cycle of the moon around the Earth around the sun repeats, and so every eighteen years ten days and eight hours (or 18 years 11 days eight hours, depending on some dense math about leap years) there occurs a very similar eclipse.

This discovery led to eclipses being grouped into families, each called a saros. Today there are 40 different saros series in progress. Our Svalbard eclipse belongs to saros 120.

For any two eclipses separated by one saros, the moon is nearly at the same position with respect to its node (that point at which the moon’s orbit crosses Earth’s orbit) and is also at almost the same distance from Earth. Not only that, the eclipse occurs at virtually the same time of year.

Saros series are not equal to a whole number of days (eighteen years ten days and eight hours). In those eight hours the earth rotates, so later eclipses are viewed by people a third of the globe away. The path for each successive eclipse in a saros series shifts about 120 degrees westward. Make your reservations for eighteen years from now accordingly.

•••••

Eclipse Excerpt 1 of 6

In anticipation of Monday’s total eclipse, this week we’ve got a series of excerpts from the Svalbard chapter of Out in the Cold, in which we traveled up to 800 miles from the North Pole in search of totality in March, 2015. Get a copy of the whole book for yourself, or order the unabridged audiobook.

ANTICIPATION

What an extraordinary run of fine weather! A woman in the grocery grabs my arm to emphasize how lucky this all is. It has almost always been cloudy “since I came up in February” (now it’s late March) – except this string of four or five fine days. The skies, the snow, the light all shine with a high latitude clarity. And it need only hold for one more day.

We are elated. If we pull this one off, we will be three for three viewing total solar eclipses, having blundered from Budapest down to Lake Balaton in a minibus in August, 1999 and then grilled kebabs out of a van on the plains wast of Nevsehir in Cappadocia, Turkey in March 2006. Almost exactly nine years later the last minute forecast is for fine weather. But it wasn’t a given that we’d be here.

Norwegian Air Shuttle pilots went on strike three weeks ago. They were our ride from Oslo to Svalbard and there was simply no question of getting here another way. The other airline flying there, SAS, was sold out when we tried to buy tickets two days after they went on sale.

It’s the damnedest thing, isn’t it? Everything works fine until it doesn’t. You plan as if your good money, paid in good faith, assures your progress around the globe, but sometimes forces of nature or the parochial affairs of men get in the way. In this case the pilots thought they could make a better living working for the parent company rather than the Balkanized series of subsidiaries that write their paychecks in the various countries Norwegian’s flights serves.

Some 700 pilots were striking and 800 cabin crew were sent home without pay. Tension rose on one particular horse farm in the southern United States. As we packed, the airline’s spokesperson, Anne-Sissel Skånvik, was less than hopeful. 

“We struggle to see how we can get to a solution,” she told Norway’s TV2.

There was some hope. An article in the Svalbard English language newspaper Icepeople reported that after missing two scheduled flights, the third, the Monday flight from Oslo, operated despite the strike. Norwegian flies the route on Mondays, Wednesdays and Fridays. Surely they would find a way to fly despite the strike.

In the end pilots and management hammered out an agreement a few days before the eclipse. Still, the strike exposed the perils of flying to an island at the end of the Earth. No backup.

•••••

Eclipse Week

Enjoy this video of the March 20, 2015 eclipse in Svalbard, beginning just before totality and running until shortly after. At the beginning, the sun appears to be out as usual while obviously something is up because meanwhile it’s getting dark on the ground.

This is why a partial eclipse just won’t do. Annie Dillard wrote that the difference between a partial eclipse and a total one is the difference between kissing a man and marrying him.

That’s it. The two just can’t be compared.

Annie Dillard’s Total Eclipse Essay

Timely reprint of this Annie Dillard essay reprinted in today’s online The Atlantic. In Out in the Cold, I quoted Ms. Dillard writing that a partial eclipse just won’t do, and what do you know, I wasn’t the only one.

“Seeing a partial eclipse bears the same relation to seeing a total eclipse as kissing a man does to marrying him, or as flying in an airplane does to falling out of an airplane.”