Solar eclipses, when the moon passes between the sun and Earth and blocks solar rays, have had a major impact on global events, from wars to scientific breakthroughs. Here are a few instances in which the astronomical phenomenon has had an impact on world events.
In the spring of 585 B.C.E., two factions were battling over land in what is now modern-day Turkey when a total eclipse stopped them in their tracks. The Lydians and the Medes had been fighting for more than 10 years when the total solar eclipse caused them to lay down their weapons for good. According to accounts by the ancient Greek historian Herodotus, who was born in the Persian Empire's city of Halicarnassus (modern-day Bodrum, Turkey), the enemies interpreted the eclipse as an omen to end their warring ways, and so they did — immediately.
The event was known as the Eclipse of Thales, after the philosopher who supposedly predicted it, independent of the battle. Referring to the prediction — the first-ever for Western scientists — science writer Isaac Asimov called the date of this eclipse the "birth of science." Some historians, though, have suggested that in compiling his histories Herodotus may have confused the solar eclipse of 585 B.C.E. with one of the two lunar eclipses that occurred in the same region two and 24 years prior.
Forging a Star Physicist
In 1919, a total solar eclipse gave the United States an opportunity to test Einstein's theory of general relativity, which posited that massive objects — like planets — cause a distortion in space and time that is experienced as gravity. Simply put, the gravity of a planet pulls space rocks into its orbit. It's like putting a bowling ball on the middle of a trampoline, causing the fabric to stretch downward, then rolling a marble around the edge and watching it travel inward toward the bowling ball.
As scientists watched the May 29, 1919, total solar eclipse off the western coast of Africa, they were able to measure the locations of stars near the solar event and calculate the warping of space-time caused by the sun's mass, which proved Einstein's theory correct and helped make him a household name.
Establishing a Partnership
And in 1937, as World War II loomed, a remote island in the Pacific became the most valuable place for researchers to observe a solar eclipse. Canton Island — now called Kanton, but also known by the nicknames Mary Island and Swallow Island — was home to expeditions by both U.S. Navy seamen and a rival British team, and the captains of both parties briefly fired shots from the bow of their ships before being advised by their respective governments to settle things down.
Eventually, the Americans and Brits entered into a friendlier competition as they vied for the best vantage point from which to view the June 8, 1937, eclipse and gather data, and the rest of the expedition continued without incident. A few years later during World War II, the two countries teamed up to use the island as a shared refueling base due to its proximity to Japan.