# Thales of Miletus and the wise men of antiquity

It was called Thales of Miletus (or Thales) because he lived in the city of Miletus, between 624 BC. - 546 B.C. He was one of the "seven wise men" of antiquity. There is no information about his writings and his life is known fractionally by the references of other authors. Philosopher of the Ionian School, author of a cosmology from which only some fragments have reached us.

He stood out mainly for his work in philosophy and mathematics. In the latter science, the first "demonstrations" of geometric theorems are attributed to him through logical reasoning and, therefore, he is considered the Father of Geometry.

According to Thales, the original principle of all things is water, from which everything proceeds and to which everything returns again. Thales is credited with using his knowledge of geometry to measure the dimensions of the Egyptian pyramids and calculate the distance from the coast to ships at sea.

There are six geometric theorems:
1.- All diameter bisects to the circumference.
2.- The angles at the base of an isosceles triangle are equal.
3.- The opposite angles of the vertex are equal.
4.- Two triangles that have two angles and one side respectively equal are equal.
5.- Every angle inscribed in a semicircle is straight.
6.- The famous "Thales theorem": the segments determined by a series of parallels cut by two transversal ones are proportional.

In astronomy he was an observer of the Little Bear and instructed the sailors to guide themselves with this constellation. He predicted the solar eclipse of 585 B.C., using Saros, a cycle of 18 years, 10 days and 8 hours.

Thales was the first to argue that the Moon shone by the reflection of the Sun and also determined the exact number of days the year has.

Thales was also the famous sage of history who fell into a pit to look at the stars and an old woman said: "You intend to observe the stars and do not even see what you have at your feet." Thales is also credited with the history of the mule that carried salt and that went into the river to dissolve it and lighten its weight; Thales took away that bad habit by loading it with sponges.

When asked about the reward he wanted for his discoveries, he replied: "I would consider myself well rewarded if the others did not attribute my findings, but recognize that they are mine."

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