The Uniformity of Motions Should Be Referenced to the Fixed Stars Not to the Equinoxes

Since the equinoctial points and other cardinal points of the celestial sphere undergo significant changes, anyone who attempts to determine the uniformity of the annual revolution based on them is bound to be mistaken. Observations over different eras have shown variations in this measurement.

Hipparchus determined the length of the year to be 365 days and a quarter of a day. However, Albategnius, the Chaldean, found it to be 365 days, 5 hours, and 46 minutes, which is 13 minutes and 3/5 of a minute shorter than the value given by Ptolemy. Later, the astronomer from Seville measured it to be 365 days, 5 hours, and 49 minutes, making it longer by one-twentieth of an hour than Albategnius’ estimate.

To ensure that these differences did not arise merely from observational errors, one must carefully examine the data and will find that the variations have always corresponded with the shifting of the equinoctial points. For example, during Ptolemy’s era, the cardinal points of the heavens shifted by one degree every hundred years. At that time, the length of the year was as recorded by Ptolemy. However, in later centuries, as these points moved more rapidly due to interactions with the lower celestial motions, the year became progressively shorter in proportion to the increased motion of the cardinal points. The faster the shifting, the shorter the time needed to complete an annual cycle.

It is therefore more accurate to define the uniformity of the year in relation to the fixed stars rather than to the equinoxes. This is exactly what I have done with the star Spica in the constellation Virgo, and I have found that the year has always been 365 days, 6 hours, and nearly one-sixth of an hour—the same value as found in ancient Egyptian records. The same principle should be applied to the motions of the planets, as their apsides and the stable laws of motion under the firmament confirm, along with the celestial sphere itself, which serves as a reliable witness.