BİRİNCİ FEN · İKİNCİ BÂB · BEŞİNCİ FASIL · Dördüncü Madde
Fourth Article
This section describes the speed, direction, slow movement, halting, return, and instability of the star Mars; its connection and proximity to the Sun.
Beloved! Know that astronomers have stated: Just as with other planets, it is observed that the star Mars sometimes exhibits rapid movement, at times a straight course, sometimes slowing down, sometimes stopping, sometimes reversing direction, and sometimes appearing unstable in its trajectory. The explanation for these occurrences is as follows: When the star finds itself upon its epicycle, if its own center's motion aligns with the center’s motion of the epicycle according to the rising of the signs, and they move together, then the star appears to be moving swiftly.
If the star inclines towards the side of the epicycle, it is observed to proceed in a straight direction. When the star descends toward the lower part of its epicycle, it appears to be moving slowly, for at that time, since the star’s center is descending, its motion is not visible, only the motion of the epicycle is seen. As the star approaches the lowest point of its epicycle, the movement of its own center coincides with the reverse of the continuous movement of the epicycle's carrier; these two movements being opposed and contrary to each other, the star appears to be at rest. When the star has completely descended to the lower part of the epicycle, its own center’s motion exceeds that of the epicycle’s center [45/b]. In this case, the star appears to be reversing direction. After the star's reversal is complete and the two motions again become equal, it then appears to be at rest a second time. Following this second apparent stillness, it appears once more to be moving slowly.
For when the star’s center has risen to the place of turning of the epicycle, its motion is again not visible, only the motion of the epicycle's center is seen. And after this slowing down, it then appears to be proceeding in a straight direction and swiftly.
However, this star also completes its revolution within its own epicycle, without doubt; for as has already been explained, the movements of all stars and spheres are similar with respect to their respective girdle-spheres, being simple and straightforward.
The first station is called the "first standing" before the star’s reversal, and the second standing is called the “second standing” after its reversal. The duration of Mars's period of reversal is two months and seventeen days. The duration of its straight movement is twenty-three years and three days. When the inclined sphere of this star is tilted one degree towards the south and north directions from the belt of signs, and when the epicycle’s mean apogee and apparent perigee are also tilted toward the south or north directions from that same inclined sphere by approximately two and a half degrees in latitude, the star appears to be wandering, and for this reason it is named "the bewildered."
The explanation of the connection and proximity occurring to the star Mars with respect to the sun-illuminating world is as follows: This star, like Saturn and Jupiter, always has its center’s extension from its own center to the mean apogee point of its epicycle in a position similar to the extension of the epicycle's mean apogee from the center of the Sun on the sphere of signs.
In this situation, Mars also, as with them, is always approaching the sun with a mean proximity (mukãrene-i vasatî) [498] when it is located at the mean apogee point of its epicycle. For as long as the center of the Sun is distant from the center of the epicycle, the star’s center will also be as far away as the distance of the sun from the epicycle's mean apogee point. Until the Sun meets the center of the epicycle (mukãbele) [499], the star will have descended to the epicycle’s Yerberi point. Their meeting occurs at the moment when Mars is at the Yerberi point of the epicycle. At that time, it has been observed that the distance of Mars from the Sun is greater and more than the distance at the time they are facing each other. For during the approach, the diameter of the epicycle between the Sun and Mars is calculated to be larger and longer than the diameter of the Sun’s Common-Meridian sphere at the moment they face each other.
Glory be to God, the Creator of all things with His wisdom and the One who has power over everything, whose power encompasses all things, for He has created the epicycle of Mars greater than the solar sphere, and He has made the Sun larger and more luminous than all the stars. May God Almighty, who arranges this immense operation with wisdom and artistry, be far removed from every imperfection. The time between Mars’s two approaches to the sun is calculated as two years and forty-nine days.