- Babylonian astronomy was developed primarily as mathematical theory, and in later times observation played a surprisingly minor role.
A partial list of the records of observations which have survived would include:
- Venus tablets of Ammizaduga (c. 1500 B.C.).
- Eclipse records (from very early times).
- New-moon records (from equally early times).
These records were essential in the initial stages of Babylonian astronomy but, as that science developed, the taking of new observations apparently became increasingly less important. That is, observational astronomy gave way to the mathematical analysis of the records of ancient observations, which in turn led to the mathematical prediction of current and future astronomical phenomena.
- Most characteristic of the entire effort was their solution of the problems of the motions of the sun and moon. This focus was undoubtedly due to the problem of the calendar.
Establishment of a reliable lunar calendar was essential to the Babylonians. Both solar and lunar phenomena had therefore to be understood, since a strictly lunar calendar would be of little use if lunar “months” were to get out of phase with solar “years” (seasons).
- In connection with the planets, the Babylonians were interested in isolated events such as first and last visibilities. This is in sharp contrast with the Greek approach, which was methodologically opposite.
The motions of the planets are rather complicated when viewed from earth. We believe we know why on the basis of Newtonian physics, as amended by Einstein. But the Babylonians never developed a physics in our sense of the term. Their interest, in this instance, was probably motivated by religious-philosophical reasons: Irregular, isolated occurrences among celestial bodies might foretell human fate. At this point their astronomy took a decidedly mathematical turn in an effort to predict future planetary phenomena.
- We have no evidence that the Babylonians suggested any geometrical ‘model’ of the cosmos which might support these theories. The problems were solved arithmetically, without recourse to Greek-type cosmologies.
In the most simplified view, this means that at the height of its creativity (Seleucid era), Babylonian astronomy was reduced essentially to arithmetic. Where our first thought when the term astronomy is mentioned is of telescopes and other observational devices, the Seleucid astronomer was metaphorically blind. Even so, his arithemetical models were extremely effective, leading to highly precise predictions.