By Louise Lerner | Photo copyright Wikimedia Commons

Eclipses have fascinated people since the earliest days of recorded history.

These rare astronomical events have helped explain the world around us—from ancient Mesopotamia, where they were believed to foretell the deaths of kings, all the way to the 20th century, when they helped prove Einstein’s theory of general relativity.

Such interest hasn’t dimmed. People across the United States will have an opportunity on Aug. 21 to witness the first total solar eclipse from coast to coast in 99 years. UChicago faculty, students and alumni are among the hordes of enthusiasts traveling across the country toward the area of “totality,” the 70-mile-wide stripe stretching from Oregon to South Carolina in which the moon will fully block the sun.

Ahead of this historic event, UChicago News asked scholars in fields ranging from theoretical cosmology to Islamic studies to discuss eclipses and their power. 

Prof. Michael Turner discusses solar eclipses and how the historic event has made everyone scientists for a day. Video Link: (Video by UChicago Creative)

The eclipse that proved Einstein was right

Michael Turner, Bruce V. & Diana M. Rauner Distinguished Service Professor in Physics

“Astronomers have learned a lot from eclipses, including one in 1919 that proved Einstein was right.

At the time, only a handful of people were aware of general relativity; Sir Arthur Eddington was one of them.  He led an eclipse expedition into the Atlantic to find out whether gravity would bend starlight, as predicted by general relativity. What you want to do is look at stars very close to the sun, and see whether the light coming toward us is bent by the sun’s gravity. With the moon blocking the sun, you can get that measurement, and it was exactly what Einstein predicted. The scientific community was agog. It instantly put general relativity on the map, and made Einstein a rockstar.

We’re still learning things from eclipses. One thing people will study during this event is the corona of the sun, which is the glowing aura of gases that surrounds the sun. There are still things we don’t understand about it—such as exactly why it actually burns hundreds of times hotter than the surface of the sun itself. 

A few years from now, NASA will launch a probe named after UChicago’s own Eugene Parker that will explore the sun’s corona—closer than any probe has ever come to the sun.”

Clay tablet
A clay cuneiform tablet on full moons for approximately the years 191/190-188/187 B.C. (The tablet is read at a 90 degree counterclockwise rotation) (Photo courtesy of Oriental Institute)

The royal omen

John Wee, Assistant Professor of Assyriology

“Neo-Assyrian politics were swayed by the movements of sun, moon and planets. The courts of Kings Esarhaddon (681 – 669 B.C.) and Assurbanipal (668 – c. 627 B.C.), in particular, were full of scholars who competed for the king’s favor by issuing advice based on astronomical predictions.

To ancient Mesopotamians, eclipses portended misfortune, and their dramatic manifestations constituted omens of enough significance to affect the entire land or the king himself. Even a partial eclipse could be as interesting—if not more so—than a full eclipse. Depending on the quadrant of the sun or moon obscured, misfortune was directed toward lands in the north, south, east or west. Because the moon was sometimes compared to a ‘crown,’ lunar eclipses especially foretold the deaths of kings. 

But there were ways of averting the misfortune. Certain prayers and incantations implored the gods to mitigate the omen. A so-called substitute king ritual furnished an escape for the king whose death had been foretold by eclipse: The real king leaves the court and is addressed as ‘the farmer,’ while a prisoner is dressed up and put on the throne for a short time before he’s executed—thereby fulfilling the prophecy.

So, bad for the prisoner, but eclipses are very useful for us historians. A famous solar eclipse, dated by modern methods to 15 June 763 B.C., provides a fixed point on which to anchor the chronology of Mesopotamian history in the first millennium B.C.”

Eclipse dragon
This 13th-century Middle Eastern brass candlestick base inlaid with silver and copper shows knotted serpentine dragons, a classic design for the medieval 'eclipse dragon.' (Courtesy of the Metropolitan Museum of Art, Edward C. Moore Collection, Bequest of Edward C. Moore, 1891)

Eclipse dragons

Persis Berlekamp, Associate Professor of Art History

“Astrology informed a great deal of medieval Islamic art. It references the solar calendar, which in any preindustrial society, is extremely important—it tells you when to plant, when to go to war, when to lay foundations for buildings. Any court had its astrological advisors, who had their own fans and enemies. 

One motif you see in both the art and architecture of the 12th and 13th centuries, particularly from Anatolia to Iraq, is called an eclipse dragon. It appears as a stylized knotted dragon, and it’s a reconciliation of ancient Near Eastern belief and what the astronomers of the day knew about the science of eclipses. 

According to ancient mythology, an eclipse happened when a giant celestial dragon swallowed the sun and the moon. But the medieval astronomers knew it happened when the sun and moon and the earth all lined up. So they reconciled these ideas by creating this invisible, theoretical entity, the ‘eclipse dragon,’ moving around in the sky. When its head and tail correspond to the ‘nodes’ where the courses of the heavenly bodies cross when eclipses happen, that’s when the dragon swallows the moon and sun. 

They’re associated with chaos, occlusion, uncertainty. It’s an idea that really resonated in the 12th and 13th centuries because that was a very tumultuous period for this area. The Mongols were moving across Central Asia toward Baghdad, and each time they advanced, they pushed waves of refugees further west. It was a violent time with a lot of social upheaval. 

So it’s exactly at this time that these dragons appeared on all sorts of objects, and also on civic architecture, like bridges and city walls. They were expected to help protect against the sudden onset of darkness that they represent. The most famous example is the ‘Talisman Gate’ of medieval Baghdad. The prince is holding back the forces of chaos and darkness, shown as eclipse dragons.

It’s very different from how we think about mythology and science today. In our world, it is necessary and important that educated people uphold the boundary between them. But this is an example from another era when intelligent, educated people answered to both simultaneously. If we can get our heads around that, it really expands our understanding of the range of ways art has mattered in the long, varied, history of human experience.”

Lunar eclipse
Moon phases and eclipse illustrated by the great tenth-century Persian scholar Al-Biruni. (Photo courtesy of Wikimedia Commons)

Ordinary end-of-days

Alireza Doostdar, Assistant Professor of Islamic Studies and the Anthropology of Religion

“In the Islamic tradition, a solar eclipse is both ordinary and extraordinary. It is extraordinary in the sense that it disrupts our everyday expectation of night and day and their regularity; in this sense, it is another sign of God's power. It is ordinary in the sense that it is part of a divine plan and has no significance beyond its attestation of divine omnipotence.

There is a famous story about a solar eclipse that occurred right after the death of the prophet Muhammad’s child Ibrahim. Some in the Muslim community took this to be an omen or a sign that the sun was grieving. But Muhammad insisted that an eclipse was merely a sign of God, and people should take the opportunity to pray. To this day, many Muslims pray the ‘salat al-kusuf’ (solar eclipse prayer) or ‘salat al-ayat” (prayer of signs) when a solar eclipse occurs in their vicinity. 

While eclipses are ordinary in the sense I have described, Islamic descriptions of the end times and Judgment Day often include phenomena that resemble a lunar or solar eclipse (or both at the same time). For example, Chapter 75 of the Qur’an reads, in part: ‘So when vision is dazzled, and the moon darkens, and the sun and the moon are joined, man will say on that Day, ‘Where is the escape?’ No! There is no refuge. To your Lord, that Day, is the place of permanence.’

With these end-times accounts in mind, we can see a solar eclipse as yet another kind of sign: A reminder that the end of our world may have something to do with the death of our sun, and that ultimately, even something as seemingly permanent as the sun will one day cease to be.”

Eclipse gif

Originally published on August 15, 2017.