Lunar theory

By virtue of its proximity, small irregularities in lunar motion are discernible more easily than those of the planets, and Ptolemy was the first to discover that the Moon was subject to an anomaly that had not been detected by Hipparchus. As we have seen, Hipparchus treated the longitude and latitude theories for the Moon separately, and Ptolemy did the same but, whereas the latitude theory was not modified by Ptolemy, he found the longitude theory to be inadequate away from the syzygies.

As far as concerns the [moon's] syzygies ... we find that the hypotheses set out above for the first, simple anomaly is sufficient, even if we employ it just as it is, without any change. But for particular positions [of the moon] at other sun-moon configurations one will find that it is no longer adequate, since ... we have discovered that there is a second lunar anomaly, related to its distance from the

0 0

Post a comment