It is apparent from the history of science, that few-body problems have an interdis ciplinary character. Newton, after solving the two-body problem so brilliantly, tried his hand at the Sun-Earth-Moon system. Here he failed in two respects: neither was he able to compute the motion of the moon accurately, nor did he understand the reason for that. It took a long time to understand the fundamental importance of Newton's failure, and only Poincare realised what was the fundamental difficulty in Newtons programme. Nowadays, the term deterministic chaos is associated with this problem. The deep...