The eclipse that ended a war and shook the gods forever

In the spring of 585 BC in the eastern Mediterranean, the moon came out of nowhere to hide the face of the sun, turning day into night.

Back then, solar eclipses were shrouded in frightening uncertainty. But a Greek philosopher is said to have predicted the disappearance of the sun. His name was Thales. He lived on the Anatolian coast – now in Turkey but then the cradle of the first Greek civilization – and was said to have acquired his unusual power by abandoning the gods.

The eclipse had an immediate worldly impact. The kingdoms of the Medes and Lydians had fought a brutal war for years. But the eclipse was interpreted as a very bad omen and the armies quickly laid down their weapons. The terms of the peace included the marriage of the daughter of the king of Lydia to the son of the king of the Medes.

Thales' impiety had a more lasting impact, his reputation soaring over the centuries. Herodotus related his prediction. Aristotle called Thales the first person to explore nature. The classical age of Greece honored him as the most important of his seven sages.

Today, the story illustrates the ancients' amazement at the disappearance of the sun and their great surprise that a philosopher knew about it in advance.

The episode also marks a turning point. For centuries solar eclipses were feared as portents of calamity. The kings trembled. Then, about 2,600 years ago, Thales led a philosophical charge that replaced superstition with rational eclipse prediction.

Today, astronomers can determine, to the second, when the sun will disappear on April 8 across North America. Weather permitting, it is expected to be the most-watched astronomical event in American history, surprising millions of skywatchers.

“Everywhere you look, since modern times, everyone wanted to predict” what the heavens would hold, said Mathieu Ossendrijver, an Assyriologist at the Free University of Berlin. He said the Babylonian kings “were scared to death of eclipses.” In response, rulers scanned the skies in an effort to anticipate bad omens, appease the gods, and “strengthen their legitimacy.”

By all accounts, Thales initiated the rationalist vision. He is often considered the world's first scientist, the founder of a radically new way of thinking.

Patricia F. O'Grady, in her 2002 book on the Greek philosopher, called Thales “brilliant, truthful, and courageously speculative.” She described his great achievement in seeing that the fraught world of human experience arises not from the whims of the gods but from “nature itself,” beginning civilization's hunt for his secrets.

Long before Thales, the ancient landscape bore clues to a successful eclipse prediction. Modern experts say Stonehenge – one of the world's most famous prehistoric sites, whose construction began around 5,000 years ago – may have been able to warn of lunar and solar eclipses.

While the ancient Chinese and Mayans noted the dates of eclipses, few ancient cultures learned to predict their disappearances.

The first clear evidence of success comes from Babylon, an empire in ancient Mesopotamia where court astronomers made nocturnal observations of the moon and planets, typically in relation to the gods and magic, astrology, and numerical mysticism.

Starting around 750 BC, Babylonian clay tablets record accounts of eclipses. Thanks to eclipse counts, the Babylonians were able to discern patterns of celestial cycles and eclipse seasons. Court officials could therefore warn of God's displeasure and seek to avoid punishments, such as the downfall of a king.

The most extreme measure was to employ a scapegoat. The substitute king performed all the usual rites and duties, including those of marriage. The replacement king and queen were then killed as a sacrifice to the gods, while the real king remained hidden until the danger passed.

Initially, the Babylonians focused on recording and predicting eclipses of the moon, not the sun. The different sizes of the eclipse shadows allow us to observe a greater number of lunar disappearances.

Earth's shadow is so large that, during a lunar eclipse, it blocks sunlight from an immense region of outer space, making the moon's disappearance and reappearance visible to everyone on the planet's night side. The size difference is reversed in a solar eclipse. The Moon's relatively small shadow makes observation of totality – the complete disappearance of the Sun – quite limited in geographical terms. In April, the overall route over North America will vary in width between 108 and 122 miles.

Long ago, the same geometry reigned. So the Babylonians, for opportunity, focused on the moon. Ultimately, they noticed that lunar eclipses tend to repeat every 6,585 days – or roughly every 18 years. This led to groundbreaking breakthroughs in predicting the probabilities of lunar eclipses, despite knowing little about the cosmic realities behind the disappearances.

“They could predict them very well,” said John M. Steele, a historian of ancient science at Brown University and contributor to a recent book, “Eclipse and Revelation.”

This was the world into which Thales was born. He grew up in Miletus, a Greek city on the western coast of Anatolia. He was a maritime power. The city's fleets established extensive trade routes and large numbers of tribute-paying colonies, making Miletus wealthy and a star of early Greek civilization before Athens rose to prominence.

Thales was said to have come from one of the illustrious families of Miletus, to have traveled to Egypt and perhaps Babylon, and to have studied the stars. Plato said that Thales had once fallen into a well while he was examining the night sky. A servant, he reported, mocked the thinker because she was so eager to know the sky that she ignored what lay at her feet.

It was Herodotus who, in the “Histories,” told of Thales predicting the solar eclipse that ended the war. He said that the ancient philosopher had anticipated the date of the sun's disappearance “within the year” of the actual event – ​​far from today's precision.

Modern experts, since 1864, however, question the ancient statement. Many considered it apocryphal. In 1957 Otto Neugebauer, a historian of science, called it “very doubtful”.

In recent years the thesis has received new acclaim. The updates are based on knowledge of the type of observation cycles that Babylon pioneered. These models are believed to allow Thales to make solar predictions that, if unsure, may still be successful from time to time.

If Stonehenge could do it occasionally, why not Thales?

Mark Littmann, an astronomer, and Fred Espenak, a retired NASA astrophysicist who specialized in eclipses, argue in their book, “Totality,” that the date of the war eclipse was relatively easy to predict, but not its exact location. Consequently, they write, Thales “could have warned against possibility of a solar eclipse.”

Leo Dubal, a retired Swiss physicist who studies artifacts from the ancient past and recently wrote about Thales, agrees. The Greek philosopher could have known the date with great certainty despite being unsure of the places where the eclipse could have been visible, for example on the front lines of war.

In an interview and a recent essay, Dr. Dubal argued that generations of historians have confused the philosopher's informed intuition with the precision of a modern prediction. He said that Thales understood perfectly, just as the ancient Greeks claimed.

“He was lucky,” Dr. Dubal said, calling this a regular part of the discovery process in scientific investigation.

Over the centuries, Greek astronomers learned more about the Babylonian cycles and used that knowledge as a basis to advance their own work. What was marginal in Thales' time became more reliable, including advance knowledge of solar eclipses.

The Antikythera Mechanism, an extraordinarily complex mechanical device, is a testament to Greek progress. It was made four centuries after Thales, in the 2nd century BC, and was found off the coast of a Greek island in 1900. Its dozens of gears and dials allow it to predict many cosmic events, including the dates of solar eclipses, although not , as usual, their precision. paths of totality.

For centuries, even into the Renaissance, astronomers continued to update their eclipse predictions based on what the Babylonians had first experienced. The 18-year cycle, said Dr. Steele of Brown University, “has had a really long history because it has worked.”

Then came a revolution. In 1543, Nicolaus Copernicus placed the Sun – and not the Earth – at the center of planetary motions. His breakthrough in cosmic geometry led to detailed studies of the mechanics of eclipses.

The superstar was Isaac Newton, the towering genius who in 1687 unveiled the universe with his law of gravitational attraction. His discovery made it possible to predict the exact paths of not only comets and planets, but also the sun, moon and Earth. As a result, the accuracy of eclipse predictions has skyrocketed.

Newton's good friend Edmond Halley, who lent his name to a bright comet, showed off the new powers to the public. In 1714 he published a map showing the expected path of a solar eclipse across England the following year.

Halley asked observers to determine the actual extent of totality. Scholars are calling it history's first large study of a solar eclipse. In terms of accuracy, his predictions surpassed those of the Astronomer Royal, who advised the British monarchy on astronomical matters.

Today's specialists, using Newton's laws and banks of powerful computers, can predict the movements of stars millions of years in advance.

But closer to home, they have difficulty making eclipse predictions for such long periods of time. This is because the Earth, Moon, and Sun are in relative proximity and therefore exert a relatively strong gravitational force on each other that changes slightly in strength over the eons, slightly altering planetary rotations and positions.

Despite such complications, “it is possible to predict eclipse dates more than 10,000 years into the future,” Dr. Espenak, a former NASA expert, said in an interview.

He created the space agency's web pages that list solar eclipses to come, including some nearly four millennia from now.

So if you're excited about the totality of April 8, you might consider what's in store for anyone living in what we now call Madagascar on August 12, 5814. According to Dr. Espenak, that date will be characterized by the phenomenon of day turning to night and again in the day: a spectacle of nature, not of evil gods.

Perhaps it is worth reflecting for a moment because, if nothing else, it represents yet another testimony to Thales' wisdom.

Leave a Reply

Your email address will not be published. Required fields are marked *