Siddhanta Shiromani (Crown of Treatises)

...the stars situated in the region facing the poles original: "गोत्राभिमुखो" — referring to the mountain-like axis of the world are called the Poles dhruva.

Without the rotation of the Celestial Sphere bha-cakra The sphere of fixed stars and the zodiac., the determination of Planetary Motion graha-gati would not be possible. Therefore, although the "cage of the stars" bha-pañjara rotates much faster śīghratara toward the western horizon, the "sky-goers" nabhaścara A poetic term for the planets., moving at a slower speed, travel along their own paths.

By using the word "Therefore" original: "ततइति" — tata iti, the author indicates the placement of the planets within the celestial sphere as mentioned in the previous verse. Because these planets are moving within it, this is appropriate. For this reason, when the celestial sphere is struck by the Proelling Wind pravaha-anila The cosmic wind that drives the daily rotation of the heavens., it swivels toward the west. The planets, however, move with a slower motion. Because of this slower motion—which is the underlying cause—they appear like ants on a wheel.

The author uses the comparative suffix "faster" tara-pratyaya The commentator is noting the Sanskrit grammar: śīghra (fast) + tara (faster). to emphasize this speed. On their own paths, the planets are actually facing the east. How is this possible when they are part of the celestial cage that moves so much faster? It is because the rotation of the sphere—sixty Ghatis ghaṭī A unit of time equal to 24 minutes; 60 ghatis make one full day. per revolution—is perceived directly.

As the planets are carried by the faster celestial sphere toward the west, their actual eastward progress pūrvābhisāra is not immediately perceived due to their slower speed. The author will explain this further in the section on the Armillary Sphere gola. Just as a potter's wheel rotates, and an object on it might move in the opposite direction vama-gati, the planets appear to be losing ground. Although this is all stated here, it will be seen clearly at the end: the planets are constantly being "outrun" original: "जीयमाना" — literally "being conquered" or surpassed in a race. by the stars.