THALES

1. THALES “Western philosophy begins with Thales.”

2. Personal Life • Not much is known about Thales’s early life including his date of birth and when he died. He is believed to be born around 624 BC in the city of Miletus, present day Turkey. • His death has been calculated to be around 547 B.C.

3. Mathematical Contributions • Thales is known as the first Greek philosopher, mathematician and scientist. • He founded the geometry of lines • Thought to be responsible for introducing the concept of abstract geometry- lines, points, planes, etc. that are not real objects but are studied to apply to real life situations • Thales is also credited for five theorems: • “A circle is bisected by its diameter.” • “Angles at the base of any isosceles triangle are congruent.” • “If two lines intersect, the opposite angles are congruent.” • If one triangle has two angles and one side congruent to that of another triangle, the two triangles are congruent” • Thales’ Theorem- “Any angle inscribed in a semicircle is a right angle.” IfAC is a diameter, then angle B is a right angle.

4. Interesting Facts • It is possible that many of Thales’ accomplishments were not actually his. • Most information about him are references from later mathematicians and philosophers. • Is believed to be the very first mathematician.

5. Story • One story about Thales is that he used his skills at recognizing weather patterns to predict that the next season's olive crop would be bountiful. He bought all of the olive presses in the area. When his prediction came true, he made a fortune.

6. Sources • http://www.mathopenref.com/thales.html • http://www.philosophy.gr/presocratics/thales.htm • http://en.wikipedia.org/wiki/Thales • http://www.philosophers.co.uk/thales-of-miletus.html