Perspectives of the Moon's Phases
Eclipses in History
Ancient Astronomical Eclipses
- At least from the time of King Nabonassar (747 B.C.) there was a dated canon of astronomical observations which were preserved at Babylon, including a record of eclipses.
- Such a document made it possible to accurately determine the intervals between eclipses and must have made it possible to discover the l8 years cycle (more exactly the cycle of 6,585N days, which the 10th-century Greek lexicographer Suidas called the saros) and its multiple, the 54 year's cycle of 19,756 days.
- These two cycles govern the recurrence of eclipses.
- Tables based on the saros go back to the 4th century B.C.
- Eclipses of the moon give more accurately the actual time when the sun and the moon are in opposition than any other kind of observation.
A Lunar Eclipse at the Siege of Syracuse
During the struggle between Athens and Sparta (or the Athenian Empire versus the Peloponnesian League) to gain greater power and commercial dominance, open fighting erupted in 431 B.C. and expanded into the Peloponnesian War.
In 415 B.C., ten years after The Peace of Nicias was arranged, Athens mounted an expedition to capture and plunder Syracuse, a colony of the Peloponnesian League on the east coast of Sicily. After reinforcements from Sparta strengthened the defenders, it became apparent that Athens couldn't win. A retreat was the only choice.
Then just before the army's departure, in 413 B.C., a lunar eclipse occurred. Nicias, the leader of the Athens' forces, saw it as a bad omen and was paralyzed by fear. He delayed his withdrawal for a lunar month to avoid what he considered a very bad sign from the gods. Syracuse used the delay in withdrawal to destroy the Athenian fleet. The Athenian army tried to escape by land, but all were killed or enslaved. The disaster at Syracuse resulted in a loss of 200 ships and 29,000 Athenian soldiers.
So it was that the Athenian fear of the eclipse resulted in an unconditional surrender to the league in 406 B.C.
Plutarch, a Greek biographer, wrote that the cause of solar eclipses was understood by the time of the Peloponnesian War, but that lunar eclipses were still mysterious to most Greeks. It was the fear of the unknown and unexplained which cost Athens the war.
A later lunar eclipse failed to deter an attack against the tyrant of Syracuse, because by then the cause of such eclipses was widely known.
Eclipses in Ancient Rome
Students of astronomy and also of the Roman calendar have been interested in something Cicero wrote about which he said occurred in a.u.c. 350 (404 B.C.). He says it was described by the poet Ennius: "On the Nones of June the sun was covered by the moon and night." This appears to have been the solar eclipse of June 21, 400 B.C., which reached a total, or almost total, phase at Rome a few minutes after sunset. The information seems to show that in that year the calendar month of June began 16 days later than it did after the Julian reform.
On June 21-22, 168 B.C., there was an eclipse of the moon which attracted considerable attention. At the time, the Romans were at war with Macedonia, and Polybius said that this eclipse was interpreted as an omen of the eclipse of a king and therefore encouraged the Romans and discouraged the Macedonians.
A Lunar Eclipse that Contributed to the Fall of Constantinople
The Roman emperor Constantine moved the capital of his realm, in a.d. 324, to the ancient city of Byzantium, which he renamed Constantinople. For more than a thousand years, the Byzantines ruled the eastern Mediterranean and the Black Sea, and provided a strong government and a continuation of the Roman Empire despite its collapse in all of the other parts of the world. By the fifteenth century, the empire was weakened by civil wars, attacks by Crusaders, excessive taxation, and the Black Plague.
Turkish sieges of Constantinople in 1402 and 1422 made no significant progress against the awesome walls of the city, but when a young sultan, Mohammed II, took over the Turkish throne in 1451, he make preparations for a fresh assault on Constantinople.
His new resolve was based on the acquisition of a new cannon which was developed by a Hungarian engineer whose design was rejected by Constantinople because of it was short of funds to pay for it. This abnormally large weapon was 27 feet (8.24 meters) long, shot stones weighing 1,300 pounds (590 kilograms), so even the thickest walls could be broken if pounded enough. Sultan Mohammed also had an army of 250,000 men, compared to an estimated 7,000 soldiers in the city.
In April, 1453, the Turkish army laid siege and blasted the city walls with his 1300 pound boulders. Despite such heavy stoning, the defenders were able to repair the damage to their walls every night. The also repulsed three major assaults. With time, regardless of their heroic defensive efforts, the small number of Constantinopolian defenders were worn out by wall repairs and repeated attacks.
At this time, the fighting morale of the defenders was of major importance. Their fighting spirit was maintained by an old prophecy that Constantinople could never fall while the moon was waxing. Then on May 22, the full moon rose in eclipse, crushing their morale. Some reports say the eclipse darkness lasted for three hours; however, this is considered impossible because the partial phase ended 75 minutes after moonrise.
Mohammed began his final assault six days later while the moon was waning gibbous. The rapidity with which the defense collapsed demonstrated the defeatist attitude which was brought about in part by the lunar eclipse. The sack and destruction of Constantinople lasted for three days. Just as the conflict at Syracuse, the side that saw the eclipse as a bad omen lost the battle.
What a day may bring, a day may take away.
Nothing there is beyond hope, nothing that can be sworn impossible, nothing wonderful, since Zeus, father of the Olympians, made night from midday, hiding the light of the shining sun, and sore fear came upon men.
Beam of the sun! O thou that seest afar, what wilt thou be devising? O mother of mine eyes! O star supreme, reft from us in the daytime! Why hast thou perplexed the power of man and the way of wisdom, by rushing forth on a darksome track?
Sources of information for Calendar, Moon Facts, Parts 1 to 6 are located at this Calendars Bibliography Unit.