Solar eclipses have been recorded throughout history. Because we are now able to calculate when and where they will happen, they are a great way for historians to determine exactly when other events occurred.
People tend to react to a total solar eclipse according to their cultural beliefs. The Chinese believed a dragon was swallowing the Sun during an eclipse, and therefore they banged drums and symbols and shot arrows skywards to scare the dragon away. The Athenians of ancient Greece saw an eclipse (solar or lunar) as being caused by angry gods, and therefore they were regarded as bad omens. The last book of the Christian Bible predicts that an eclipse will occur, accompanied by earthquakes. Emperor Louis, head of the Frankish Empire of Western Europe, is said to have been so awestruck by the total solar eclipse of 5 May 840, that he died shortly afterwards.
Chinese astrologers wrote of an eclipse occurring over 4,000 years ago. Historians and astronomers believe that this was an eclipse that happened on 22 October 2137 BC. Two astrologers at the time, Hsi and Ho, had apparently failed to predict this eclipse, and as a result were beheaded. Another eclipse recorded in ancient history was in Mesopotamia (now Iraq and Syria), and was seen in the town of Ugarit. It is now known to have occurred on 3 May 1375 BC.
In more recent times, astronomers have used solar eclipses to help in astronomical calculations, and to discover a new element. During the eclipse of 18 August 1868, Pierre Janssen of France discovered the telltale signs of helium in the Sun’s corona. Helium became the first chemical element to be discovered outside the Earth and takes its name from the Greek word for Sun - Helios. On 29 May 1919, a total solar eclipse was used to prove Einstein’s theory of general relativity by showing that gravity can bend light.