The Babylonians lived in Mesopotamia, a fertile plain between the Tigris and Euphrates rivers (see Fig. 2.1). They developed an abstract form of writing based on cuneiform (wedge-shaped) symbols. Their symbols were written on wet clay tablets which were baked in the sun; many thousands of these tablets have survived to this day; an example is shown in Fig. 2.1.
The Babylonian apparently believed the Earth to be a big circular plane surrounded by a river beyond which lies an impassable mountain barrier, with the whole thing resting on a cosmic sea. No human may cross the river surrounding the Earth. The mountains support the vault of heaven, which is made of a very strong metal. There is a tunnel in the northern mountains that opens to the outer space and which also connects two doors, one in the East and one in the West. The sun comes out through the eastern door, travels below the metallic heavens and then exits through the western door; he spends the nights in the tunnel.
The creation myth is more lively than the Egyptian version. It imagines that the cosmic ocean Apsu mixed with chaos Tiamat and eventually generated life. For a while life was good for the gods but there came a time when Tiamat felt her domain was too small and made war against the other gods. All but Marduk were afraid of her, so Marduk, after getting all the powers from the frightened gods, fought Tiamat. When Tiamat opened her mouth to swallow him he thrust a bag full with hurricane winds into her so that she swelled and, taking advantage of her indisposition, Marduk pierced her with his lance and killed her. Then he split Tiamat's carcass making the lower half the earth and the upper the heavens. Finally Marduk mixed his own blood with the earth to make men for the service of the gods.
Babylonians and Chaldeans observed the motion of the stars and planets from the earliest antiquity (since the middle of the 23rd century B.C.). They cataloged the motion of the stars and planets as well as the occurrence of eclipses and attempted to fit their behavior to some numerical theories. Many of these observations were used for astrological prophesying and, in fact, they were the originators of astrology. They believed that the motions and changes in the stars and planets determine (or so they believed) what occurs on this planet.
The Babylonians excelled in computational mathematics, they were able to solve algebraic equations of the first degree, understood the concept of function and realized the truth of Pythagoras' theorem (without furnishing an abstract proof). One of the clay tablets dated from between 1900 and 1600 B.C. contains answers to a problem containing Pythagorean triples, i.e. numbers a , b, c with a2 + b2 = c2. It is said to be the oldest number theory document in existence. The Babylonians had an advanced number system with base 60 rather than the base 10 of common today. The Babylonians divided the day into 24 hours, each hour into 60 minutes, each minute into 60 seconds. This form of counting has survived for 40 centuries.