From Tintin to Shakespeare: solar eclipses, between science, myth and superstition
These astronomical phenomena have been read as divine omens, political weapons, and scientific evidence. Their history is also that of the transition from myth to knowledge.
Tintin, Professor Calculus and Captain Haddock are on the pyre, waiting for the Incas to light it with a large magnifying glass to concentrate the sun's light. But Tintin addresses the king of the stars and asks him to cover himself with a veil if he does not wish for his death. The sun completely darkens, causing panic among the Incas. Tintin asks the sun to shine again. The star lights up and all three are freed.
It is one of the passages from The Temple of the Sun. Tintin had read that on that day and at that hour there would be a total eclipse and had predicted that it could impress the Incas. It is very curious that a religion based on the worship of the Sun did not know how to predict an eclipse. It is very different from what happens in a story by the Guatemalan writer—born in Honduras—Augusto Monterroso: The Eclipse. Fray Bartolomé Arrazola is about to be sacrificed on an altar in Guatemala, therefore, in Mayan territory. Knowing that there would be a total eclipse that day, he tries to impress the indigenous people by telling them that he can make the sun darken. Shortly after, the blood from the religious man's heart was flowing over the altar while one of the indigenous people recited the dates on which solar and lunar eclipses would occur and which the Mayan astronomers had predicted.
Reality is much closer to Monterroso's story than to Hergé's adventure. For a long time, some peoples knew how to predict eclipses. It was all based on centuries of sky observations and pattern analysis. Around the 7th century BC, the Chaldeans had established a period called Saros. They had measured the time that passed between two eclipses. It was 6,585.3211 days, a time when three lunar cycles coincided again: the orbital period, its phase, and the nodal period—the moments when its orbit crosses the ecliptic. But they also took into account correction factors, such as the true anomaly—the angle of the satellite with respect to the perigee, the moment when the Moon is closest to the Earth, and the mean anomaly, the fraction traveled since its last passage through perigee.
The Greek Thales of Milet used, between the 7th and 6th centuries BC, a method for calculating eclipse dates. It is not known how he did it, but it is believed that he based it on systems described by Babylonians and Egyptians. About three centuries later, Aristotle did not predict eclipses, but he did use them as proof that the Earth was spherical. He deduced this from the shadow that the Earth casts on the satellite during a lunar eclipse.
The Maya also, unfortunately for Fra Bartolomeo, knew how to predict eclipses. In a study published last October in Science Advances, archaeologists John Justeson and Justin Lowry, from the State University of New York, proposed that the Maya had developed a mathematical model that served as a lunar calendar, but which later allowed them to predict these phenomena with great accuracy.
The authors analyzed in detail the Dresden Codex, a hieroglyphic manuscript dating from the 11th or 12th century which is one of the four surviving pre-Columbian Mayan books and the oldest, a copy of another book written three or four centuries earlier. It covers 405 months. Besides ritual calendars, ceremonial instructions, representations of deities, and a description of illnesses and cures, it contains extraordinarily precise astronomical tables. Thanks to the analysis of a prediction table with 69 new moon dates, the authors have concluded that it allowed predicting solar eclipses that occurred over seven centuries.
"...the sun covered the moon and one could see seven stars in the sky clearly", we can read in The Book of Deeds, by King James I, in reference to an eclipse observed in Montpellier. Computer calculations have made it possible to verify that the eclipse occurred on Friday, June 3, 1239, as Francisco Pavía Alemany and Marcelino Álvarez Villarroya explain in detail in the spring issue of the scientific popularization magazine Daualdeu, published by the Meridià Zero Association in the Marina Alta region.In the Crown of Aragon, several monarchs were interested in eclipses and in astronomy and astrology in general. In the 1290s, under the reign of James II, eclipse predictions were made, and the king himself had a Liber de eclipsi in Latin, which echoed the supposed cyclical repetition of historical events. In the 14th century, Peter the Ceremonious commissioned his astrologers Pere Engilbert and Dalmau Sesplanes to create new tables, calculated from the coordinates of Barcelona.Later, other detailed calculations appeared, such as the Perpignan Tables of 1361, by the Jewish astrologer from Perpignan, Jacob ben David Bonjom. They allowed for the precise determination of solar and lunar eclipses. They were originally written in Hebrew and later translated into Latin, Catalan, Greek, and Spanish. A century later, in 1485, the Valencian doctor Joan de Bònia created a table of solar and lunar eclipses for the municipal scrivener's office in Valencia.Calendars derived from the continuous observation of the firmament were also applied to medicine. Lunar calendars were used for so-called astrological medicine, based on the belief that health was influenced by celestial movements and the positions of the stars. Gradually, this part of traditional medicine was overshadowed by scientific practice, which was based on new knowledge in anatomy and the role of certain drugs.
The eclipse that stopped a war
The Maya called eclipses Pa’al K’in, broken sun. Both they and the Aztecs considered them predictions of catastrophes or very negative events, as in many other cultures —probably the majority. But on one occasion an eclipse promoted peace. It was in the year 585 BC, during a brutal confrontation between the armies of King Alyattes of Lydia, in present-day Turkey, and King Cyaxares of Media, in present-day Iran. In a cruel confrontation on the Halys River —currently the Kızılırmak River—, in Anatolia, a total solar eclipse occurred. Both sides thought it was a message from the gods, displeased with the war, and they suddenly stopped fighting. This forced the two monarchs to draw up and sign a peace treaty.
The view of eclipses as an omen of disasters spans centuries and various works by William Shakespeare corroborate this. The English author often speaks of astrology and in act 4 of King Lear the Earl of Kent states that “the stars above us govern our conditions.” The Earl of Gloucester thinks the same, who in the first act considers that “these late eclipses of the Sun and Moon portend no good.” The contrast is offered by his illegitimate son Edmund, who represents rational thought. Also in the first act he calls the idea foolishness and an excuse, and says that “we make the Sun, the Moon, and the stars guilty of our disasters,” as if we were “drunkards, liars, and adulterers by a forced obedience to planetary influence.” The same idea is forcefully expressed by Caius in the first act of Julius Caesar: “The fault, dear Brutus, is not in our stars, but in ourselves.”
On a clay tablet with cuneiform writing, dated around the 7th century BC, the court astrologer explains that King Ashurbanipal has asked him to predict a possible eclipse and to draw out the possible consequences that this phenomenon would have for the kingdom.A poem written on a papyrus by the Greek Archilochus of Paros describes an eclipse, dated by researchers to April 6, 647 BC, when Zeus “turned midday into night, hiding the light of the bright Sun” and adds that since then, “anything is believable and to be expected/ by humans”.In 1926, the German artist George Grosz painted a picture of a total solar eclipse, with the dollar sign above the star’s disk. He wanted to criticize the drama of the First World War and the demands of the Treaty of Versailles of 1919, with the economic interests behind it, which once again favored the rich.These are three of the more than one hundred cultural elements from all over the world and all eras that are collected in the digital map “A World of Eclipses,” created by the Spanish Astronomical Society (https://sea-mundoeclipses.es). History, science, literature, and art appear in this attractive showcase that offers testimonies of the more or less scientific attempts to explain the phenomenon, the beliefs it generated, and even its metaphorical use to criticize the society of the time.
The dragon that devoured the Sun
Shakespeare's life practically coincided with the Elizabethan era. Eclipses were still seen as omens of destruction or acts of malevolent powers. In Macbeth it is explained that one of the main components of the witches' potions are yew twigs gathered during a lunar eclipse. But in the 16th and 17th centuries, the Copernican model gradually became established, and science in general, and astronomy in particular, progressed to try to eliminate these superstitions. The astronomer and mathematician Thomas Digges and the peculiar John Dee, who was also an occultist, demonstrated the possibility of accurately predicting when solar or lunar eclipses would occur.
After Newton, astronomical calculations gained precision, and today computers allow us to know the year, day, hour, duration, and locations where an eclipse will be visible many years in advance. Thus, prediction can neither be used to save oneself from the pyre or the sacrificial altar, nor will it happen to astronomers as it did to Hsi and Ho. It is documented that in October of the year 2137 BC, an eclipse occurred in China. At that time, the Chinese thought that the culprit was a dragon that was devouring the Sun. So, people made a lot of noise to drive it away. It seems the system always worked, because the eclipse ended in a few seconds or at most in a few minutes. But Emperor Chung K'ang was not at all pleased that his two astronomers had not predicted it, and he had them executed. Of course, knowing how to predict it also did not help Fra Bartolomeo in Monterroso's short story.