The eclipse of Thales was a

solar eclipse A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of Earth, totally or partially. Such an alignment occurs approximately every six months, during the eclipse season i ...

in the early 6th century BC that was, according to the ancient Greek historian

Herodotus Herodotus (; BC) was a Greek historian and geographer from the Greek city of Halicarnassus (now Bodrum, Turkey), under Persian control in the 5th century BC, and a later citizen of Thurii in modern Calabria, Italy. He wrote the '' Histori ...

(writing about 150 years later), accurately predicted by the Greek philosopher

Thales of Miletus Thales of Miletus ( ; ; ) was an Ancient Greek pre-Socratic philosopher from Miletus in Ionia, Asia Minor. Thales was one of the Seven Sages, founding figures of Ancient Greece. Beginning in eighteenth-century historiography, many came to ...

. If Herodotus' account is accurate, this eclipse is the earliest recorded as being known in advance of its occurrence. The only solar eclipse matching the presumed place, era, and conditions of visibility necessary to explain the historical event is the eclipse of 28 May 585 BC. How exactly Thales could have predicted a solar eclipse remains uncertain, and modern scholars are skeptical of the story's veracity. Some have argued for different dates, or for other interpretations of Herodotus's account. According to Herodotus, the change of day into night was interpreted as an omen, and interrupted a battle (sometimes called the "Battle of the Eclipse") in a long-standing war between the

Medes The Medes were an Iron Age Iranian peoples, Iranian people who spoke the Median language and who inhabited an area known as Media (region), Media between western Iran, western and northern Iran. Around the 11th century BC, they occupied the m ...

and the

Lydians The Lydians (Greek language, Greek: Λυδοί; known as ''Sparda'' to the Achaemenids, Old Persian cuneiform Wikt:𐎿𐎱𐎼𐎭, 𐎿𐎱𐎼𐎭) were an Anatolians, Anatolian people living in Lydia, a region in western Anatolia, who spo ...

Anatolia Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...

(present-day

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

). American writer

Isaac Asimov Isaac Asimov ( ; – April 6, 1992) was an Russian-born American writer and professor of biochemistry at Boston University. During his lifetime, Asimov was considered one of the "Big Three" science fiction writers, along with Robert A. H ...

described this battle as the earliest historical event whose date is known with precision to the day, and called the prediction "the birth of science".

Ancient accounts

writes that in the sixth year of the war, the Lydians and the Medes were engaged in an indecisive battle when suddenly day turned into night, leading to both parties halting the fighting and negotiating a peace agreement. Herodotus also mentions that the loss of daylight had been predicted by

. He does not, however, mention the location of the battle. As part of the terms of the peace agreement, Alyattes's daughter Aryenis was married to Cyaxares's son Astyages, and the

Halys River Halys may refer to: * Health-adjusted life years (HALYs), a type of disability-adjusted life year which are used in attempts to quantify the burden of disease or disability in populations * Halys River, a western name for the Kızılırmak River ...

(present-day

Kızılırmak River The Kızılırmak (, Turkish language, Turkish for "Red River"), once known as the Halys River () and Alis River, is the longest river flowing entirely within Turkey. It is a source of hydroelectric power and is not used for navigation. Geogra ...

) was declared to be the border of the two warring nations. Other ancient sources after

also mention the eclipse.

Diogenes Laërtius Diogenes Laërtius ( ; , ; ) was a biographer of the Greek philosophers. Little is definitively known about his life, but his surviving book ''Lives and Opinions of Eminent Philosophers'' is a principal source for the history of ancient Greek ph ...

(3rd century AD) says that

Xenophanes Xenophanes of Colophon ( ; ; – c. 478 BC) was a Greek philosopher, theologian, poet, and critic of Homer. He was born in Ionia and travelled throughout the Greek-speaking world in early classical antiquity. As a poet, Xenophanes was known f ...

, who lived in the same century as Thales, was impressed with the prediction, and he also gives additional testimonies from the

pre-Socratic Pre-Socratic philosophy, also known as early Greek philosophy, is ancient Greek philosophy before Socrates. Pre-Socratic philosophers were mostly interested in cosmology, the beginning and the substance of the universe, but the inquiries of the ...

Democritus Democritus (, ; , ''Dēmókritos'', meaning "chosen of the people"; – ) was an Ancient Greece, Ancient Greek Pre-Socratic philosophy, pre-Socratic philosopher from Abdera, Thrace, Abdera, primarily remembered today for his formulation of an ...

and

Heraclitus Heraclitus (; ; ) was an Ancient Greece, ancient Greek Pre-Socratic philosophy, pre-Socratic philosopher from the city of Ephesus, which was then part of the Achaemenid Empire, Persian Empire. He exerts a wide influence on Western philosophy, ...

Cicero Marcus Tullius Cicero ( ; ; 3 January 106 BC – 7 December 43 BC) was a Roman statesman, lawyer, scholar, philosopher, orator, writer and Academic skeptic, who tried to uphold optimate principles during the political crises tha ...

(1st century BC) mentions that Thales was the first man to successfully predict a solar eclipse during the reign of Astyages, the last king of the Median empire.

Pliny the Elder Gaius Plinius Secundus (AD 23/24 79), known in English as Pliny the Elder ( ), was a Roman Empire, Roman author, Natural history, naturalist, and naval and army commander of the early Roman Empire, and a friend of the Roman emperor, emperor Vesp ...

(1st century AD) mentions as well that Thales had predicted a solar eclipse during the reign of

Alyattes of Lydia Alyattes (Lydian language: ; ; reigned c. 635 – c. 585 BC), sometimes described as Alyattes I, was the fourth king of the Mermnad dynasty in Lydia, the son of Sadyattes, grandson of Ardys, and great-grandson of Gyges. He died after a re ...

Modern interpretations

If the description by Herodotus of the event is read as a solar eclipse, then based on modern astronomical calculations, it can be identified with an eclipse on 28 May 585 BC which peaked over the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

at , whose umbral path reached southwestern

in the evening hours. For the location of the battle, some scholars assume the

, as it was located in the border region between both kingdoms, and is just within the error margin of the eclipse's computed path. However, such a reading is disputed by some historians of science. At the time of

Thales Thales of Miletus ( ; ; ) was an Ancient Greek philosophy, Ancient Greek Pre-Socratic philosophy, pre-Socratic Philosophy, philosopher from Miletus in Ionia, Asia Minor. Thales was one of the Seven Sages of Greece, Seven Sages, founding figure ...

' purported prediction, it was not yet known that eclipses were caused by the Moon coming between the Earth and the Sun, a fact that would not be discovered until over a century later by either

Anaxagoras Anaxagoras (; , ''Anaxagóras'', 'lord of the assembly'; ) was a Pre-Socratic Greek philosopher. Born in Clazomenae at a time when Asia Minor was under the control of the Persian Empire, Anaxagoras came to Athens. In later life he was charged ...

Empedocles Empedocles (; ; , 444–443 BC) was a Ancient Greece, Greek pre-Socratic philosopher and a native citizen of Akragas, a Greek city in Sicily. Empedocles' philosophy is known best for originating the Cosmogony, cosmogonic theory of the four cla ...

. If the account is true, it has been suggested that Thales would have had to calculate the timing of any eclipse by recognizing patterns in the periodicities of eclipses. It has been postulated that Thales may have used the Saros cycle in his determination, or that he may have had some knowledge of

Babylonian astronomy Babylonian astronomy was the study or recording of celestial objects during the early history of Mesopotamia. The numeral system used, sexagesimal, was based on 60, as opposed to ten in the modern decimal system. This system simplified the ca ...

. However, Babylonians were far from being able to predict the local conditions of solar eclipses at that point, which makes this hypothesis highly unlikely. At the time, there was no known cycle that could be reliably used to predict an eclipse for a given location and, therefore, any accurate prediction would have been down to luck. Others are skeptical of other details of the story. The eclipse would have occurred shortly before sunset at any plausible site of the battle, and it was very uncommon for battles to take place at that time of day. Furthermore, based on the list of Medean kings and their regnal lengths reported elsewhere by Herodotus, Cyaxares died 10 years before the eclipse. Otta Wenskus
''Die angebliche Vorhersage einer Sonnenfinsternis durch Thales von Milet. Warum sich diese Legende so hartnäckig hält und warum es wichtig ist, ihr nicht zu glauben.''
In: ''Hermes.'' vol. 144, no. 1, 2016, pp. 2–17 (German). An alternative theory is that the solar eclipse story is a misinterpretation of Herodotus's text, and that the battle might have instead been disrupted by a eclipse just before moonrise, at dusk.Thomas D. Worthen, "Herodotus's Report on Thales's Eclipse," ''Electronic Antiquity'' vol. 3.7 (May 1997)

and Thomas De Voe Worthen,
The Eclipse of 585 BCE
" If the warriors had planned their battle activities expecting a full moon as in the previous few days, it would have been a shock to have dusk fall suddenly as an occluded moon rose. If this theory is correct, the battle's date would not be 585 BC (date given by Pliny based on date of solar eclipse), but possibly 3 September 609 BC, or 4 July 587 BC, dates when such dusk-time lunar eclipses did occur.

References

External links

Wired.com: May 28, 585 B.C.: Predicted Solar Eclipse Stops Battle
{{Solar eclipses, state = expanded 585 BC

6th century BC Ancient astronomy 6th-century BC conflicts Battles involving Lydia Battles involving the Median kingdom

Ancient accounts

Modern interpretations

See also

References

Further reading

External links