There is considerable agreement that Thales was born in Miletus in Greek Ionia in the 624 BCE and died in about 546 BCE. His parents are said by some to be from Miletus but others report that they were Phoenicians. It is reported that Thales predicted an eclipse of the Sun in 585 BC. .. Thales was much involved in the problems of astronomy and provided a number of explanations of cosmological events which traditionally involved supernatural entities. Thales's prediction of the 585 BC eclipse was probably a guess based on the knowledge that an eclipse around that time was possible. [Thales] even succeeded in measuring the pyramids by observation of the length of their shadow at the moment when our shadows are equal to our own height. This appears to contain no subtle geometrical knowledge, merely an observation that at the instant when the length of the shadow of one object coincides with its height, then the same will be true for all other objects.

Thales is said to have travelled in Egypt, and to have thence brought to the Greeks the science of geometry. . He is unanimously ascribed the introduction of mathematical and astronomical sciences into Greece Thales of Miletus was the first known Greek philosopher, scientist and mathematician. Some consider him to be the teacher of of Pythagoras, though it may be only that he advised Pythagoras to travel to Egypt and Chaldea. None of his writing survives; this makes it is difficult to determine his philosophy and to be certain about his mathematical discoveries. He is credited with five theorems of elementary geometry. Aristotle described Thales as the founder of natural philosophy

Thales of Miletus taught that 'all things are water'. Thales believed that the Earth floats on water and all things come to be...