On this day in 585 BC a Greek philosopher named Thales successfully predicted a solar eclipse. The Greek historian, Herodotus, who was one of his contemporaries, tells us that the eclipse happened during a battle between the Medes and the Lydians. According to him, it began when someone cooked up someone else’s son and served him to the king for dinner. It was a war that had raged for six years without either side gaining any particular advantage. On this day, just as the battle was in full swing it suddenly grew dark. In Ancient Greece, a solar eclipse was taken as a sign that the gods were angry, so both sides put down their weapons and were eager to agree a peace.
Herodotus tells us that Thales had predicted only the year of the eclipse, but it seems impossible to predict the year of a solar eclipse without also knowing the day. In truth, we don’t really know how he did it, history doesn’t tell us. Aristotle regarded Thales as the first Greek philosopher to try to explain the world about him without falling back on mythology. None of his writing survives so we only know what other people said about him. We know that Thales thought the earth floated on water, in the same way that ships do. His theory was supported by the fact that people believed in, and had definitely seen, floating islands. He thought that earthquakes were caused by waves in the water that was holding us all up. He may not have been quite right, but it was a better guess than the ‘angry gods’ explanation that was the ‘go to’ answer for anything bad that happened. He managed to work out that the Earth was round though. He knew it must be spherical, because he had observed ships disappearing over the horizon.
There is a tale that he once fell into a well, because he was so busy looking up at the stars and wasn’t looking where he was going. The moral of the story being, that people should be a bit more practical and not have their head in the clouds. However, it is just possible that Thales got into the well on purpose. The Ancient Greeks knew that the stars were still in the sky during the day, but they were just not visible. Unless there was a solar eclipse of course. But they also knew that if you looked into a very deep well, you could sometimes see the stars reflected in the water. So if you are ever unlucky enough to find yourself at the bottom of a very deep well, look up and you will see that the sky looks dark and full of stars, even in the day time.
Maybe after this incident, he was keen to prove that philosophy had its practical advantages. Thales had managed to pinpoint the dates of the Summer and Winter solstices, and therefore, the length of the solar year. He also noticed the changing of the seasons. He must have kept an eye on the changing weather patterns too, because there was a year in which he managed to predict a particularly good olive harvest. He was so confident that he bought up all the olive presses in his home city of Miletus. These he either used himself or rented them out at a high price when everyone suddenly had loads of olives that needed pressing. Aristotle insists that he did this, not for his own gain, but to prove to people that philosophy was not as useless as they thought.