FIRST SCIENCE · SECOND CHAPTER · FIFTH SECTION · Third Article
Third Article
This article explains the aphelion and perihelion of the luminous sun, the nodes which are the equinox points (nokta-i itidal), and its slow and rapid movement.
O dear one! It should be known that the scholars of astronomy have said as follows: The location of the aphelion of the sun, the lamp of the cosmos, in the zodiacal sphere was determined in the year [Ğasîr] of the Rūmī calendar at the twenty-seventh degree of the sign of Gemini. In the same year, the location of the perihelion was determined at the twenty-seventh degree of the sign of Sagittarius.
Currently, [in the year when Maʿrifetnāme was composed], the Rūmī calendar has reached the year 2069, and the Hijrī calendar has reached the year 1170. Thus, according to what has been explained above, each of the aphelion and perihelion points has advanced approximately eight degrees up to the aforementioned date. Therefore, the sun's aphelion has reached the fourth degree of the sign of Cancer, and the perihelion has likewise reached the fourth degree of the sign of Capricorn.
This is because the eccentric sphere of the luminous sun is located on the surface of the zodiacal belt. Therefore, the ascending and descending nodes have only been considered as the two intersection points of the zodiacal belt and the equator, one of which is Aries and the other is Libra. Thus, when the Sun is at the beginning of Aries, it has reached the ascending node. When it is at the beginning of Libra, it has reached the descending node.
As for the other planets; their aphelion points are found at the two opposite points formed by the intersection of their own deferent spheres with the zodiacal belt. From this belt, the place where the deferent spheres incline towards the north direction is called the ascending node; the place where they incline towards the south direction is called the descending node. As has been detailed above, for this reason, there is never any difference in latitude observed in the sun, whereas in the movements of the other planets, a difference in latitude has been observed. In the sun, only a difference in longitude has been observed. That is to say, the Sun moves slowly in the signs of Aries, Taurus, Gemini, Cancer, Leo, and Virgo, which are in the northern hemisphere. In the signs of Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces, which are in the southern hemisphere, it moves rapidly.
In essence, although the movements of all the other spheres resemble each other and even sometimes appear to be equal in a certain uniformity, the reasons for the acceleration and deceleration observed in the sun's movements are as follows: when the sun's aphelion is at the beginning of Cancer in the zodiacal sphere, and the perihelion is at the beginning of Capricorn, the time it takes to traverse the signs in the southern hemisphere is one week longer than the time it takes to traverse the signs in the northern hemisphere. The reason for this delay is as follows: the center of the sun revolves and moves around a circle whose center is outside the center of the cosmos. Therefore, in one half of the zodiacal sphere, the Sun remains longer than it does in the corresponding half of the eccentric sphere. And this is the half in which the sun's aphelion is calculated. In the other half of the zodiacal sphere, less than half of the eccentric sphere remains. This is the half where the sun's perihelion is located. For the Sun cannot traverse half of the zodiacal sphere with its own movement until it has passed the corresponding half of its own circle.
Thus, the time it takes for the sun to traverse one half of the zodiacal sphere must necessarily differ from the time it takes to traverse the second half. In this case, the movement of the sun from the half of the zodiacal sphere that is the perihelion towards the other half that is the aphelion appears slower. For the time to traverse the aphelion half is eight days longer than the time to traverse the perihelion half. However, the sun's movement in its eccentric sphere is not different; it is circular, continuous, and similar. All these phenomena occur "by the decree of Allah, the Mighty and All-Knowing, in the truest sense." (See Yā Sīn 36:38, al-Anʿām 6:96)
"We glorify Allah, Who creates His creatures with wisdom and artistry. Exalted is His majesty." [47/b]