Archimedes of Syracuse
Archimedes of Syracuse (ca 287 - ca 212 BC) was an ancient Greek mathematician, physicist, engineer, astronomer, and inventor from the city of Syracuse.
His mathematical achievements include, among others, deriving the approximation:
223 / 71 < π < 22 / 7
with an accuracy of 2·10-5 and 4·10-5, respectively.
He devised a system using exponentiation for expressing very large numbers. Exponentiation is a mathematical operation involving two numbers, the base b and the exponent or power n. It is usually written as bn using a superscript.
In physics he proofed the law of the lever, the concept of center of gravity, and the law of buoyancy better known as Archimedes' principle.
In astronomy, he measured the apparent diameter of the Sun and the size of the universe. He is said to have built a planetarium device.
He is credited with designing the screw pump, the compound pulley, and defensive war machines.