The information the Qur'an provides on this subject mainly deals with the solar system. References are however made to phenomena that go beyond the solar system itself: they have been discovered in recent times. There are two very important verses on the orbits of the Sun and Moon:
--sura 21, verse 33:
"(God is) the One Who created the night,and day, the sun and the moon. Each one is travelling in an orbit with its own motion."
--sura 36, verse 40:
"The sun must not catch up the moon, nor does the night outstrip the day. Each one is travelling in an orbit with its own motion."
Here an essential fact is clearly stated: the existence of the Sun's and Moon's orbits, plus a reference is made to the traveling of these bodies in space with their own motion. A negative fact also emerges from a reading of these verses: it is shown that the Sun moves in an orbit, but no indication is given as to what this orbit might be in relation to the Earth. At the time of the Qur'anic Revelation, it was thought that the Sun moved while the Earth stood still. This was the system of geocentrism that had held away since the time of Ptolemy, Second century B.C., and was to continue to do so until Copernicus in the Sixteenth century A.D. Although people supported this concept at the time of Muhammad, it does not appear anywhere in the Qur'an, either here or elsewhere.
The Existence of the Moon's and the Sun's Orbits.
The Arabic word falak has here been translated by the word 'orbit'; many French translators of the Qur'an attach to it the meaning of a 'sphere'. This is indeed its initial sense. Hamidullah translates it by the word 'orbit'. The word caused concern to older translators of tne Qur'an who were unable to imagine the circular course of the Moon and the Sun and therefore retained images of their course through space that were either more or less correct, or hopelessly wrong.
Si Hamza Boubekeur in his translation of the Qur'an cites the diversity of interpretations given to it: "A sort of axle, like an iron rod, that a mill turns around; a celestial sphere, orbit, sign of the zodiac, speed, wave . . .", but he adds the following observation made by Tabari, the famous Tenth century commentator:
"It is our duty to keep silent when we do not know." (XVII, 15).
This shows just how incapable men were of understanding this concept of the Sun's and Moon's orbit. It is obvious that if the word had expressed an astronomical concept common in Muhammad's day, it would not have been so difficult to interpret these verses. A new concept therefore existed in the Qur'an that was not to be explained until centuries later.
1. The Moon's Orbit.
Today, the concept is widely spread that the Moon is a satellite of the Earth around which it revolves in periods of twenty-nine days. A correction must however be made to the absolutely circular form of its orbit, since modern astronomy ascribes a certain eccentricity to this, so that the distance between the Earth and the Moon (240,000 miles) is only the average distance. We have seen above how the Qur'an underlined the usefulness of observing the Moon's movements in calculating time (sura 10, verse 5, quoted at the beginning of this chapter.) This system has often been criticized for being archaic, impractical and unscientific in comparison to our system based on the Earth's rotation around the Sun, expressed today in the Julian calendar.
This criticism calls for the following two remarks:
a) Nearly fourteen centuries ago, the Qur'an was directed at the inhabitants of the Arabian Peninsula who were used to the lunar calculation of time. It was advisable to address them in the only language they could understand and not to upset the habits they had of locating spatial and temporal reference-marks which were nevertheless quite efficient. It is known how well-versed men living in the desert are in the observation of the sky; they navigated according to the stars and told the time according to the phases of the Moon. Those were the simplest and most reliable means available to them.
b) Apart from the specialists in this, most people are unaware of the perfect correlation between the Julian and the lunar calendar: 235 lunar months correspond exactly to 19 Julian years of 365.25 days. Then length of our year of 365 days is not perfect because it has to be rectified every four years (with a leap year): With the lunar calendar, the same phenomena occur every 19 years (Julian). This is the Metonic cycle, named after the Greek astronomer Meton, who discovered this exact correlation between solar and lunar time in the Fifth century B.C.
2. The Sun.
It is more difficult to conceive of the Sun's orbit because we are so used to seeing our solar system organized around it. To understand the verse from the Qur'an, the position of the Sun in our galaxy must be considered. and we must therefore call on modern scientific ideas. Our galaxy includes a very large number of stars spaced so as to form a disc that is denser at the centre than at the rim. The Sun occupies a position in it which is far removed from the centre of the disc. The galaxy revolves on its own axis which is its centre with the result that the Sun revolves around the same centre in a circular orbit. Modern astronomy has worked out the details of this. In 1917, Shapley estimated the distance between the Sun and the centre of our galaxy at 10 kiloparsecs i.e., in miles, circa the figure 2 followed by 17 zeros. To complete one
revolution on its own axis, the galaxy and Sun take roughly 250 million years. The Sun travels at roughly 150 miles per second n the completion of this. The above is the orbital movement of the Sun that was already referred to by the Qur'an fourteen centuries ago. The demonstration of the existence and details of this is one of the achievements of modern astronomy.
Reference to the Movement of the Moon and the Sun
in Space With Their Own Motion.
This concept does not appear in those tranislations of the Qur'an that have been made by men of letters. Since the latter know nothing about astronomy, they have translated the Arabic word that expresses this movemcnt by one of the meanings the word has: 'to swirn'. They have done this in both the French translations and the, otherwise remarkable, English translation by Yusuf Ali. The Arabic word referring to a movement with a self-propelled motion is the verb sabaha (yasbahuna in the text of the two verses). All the senses of the verb imply a movement that is associated with a motion that comes from the body in question. If the movement takes place in water, it is 'to swim'; It is 'to move by the action of one's own legs' if it takes place on land. For a movement that occurs in space, it is difficult to see how else this meaning implied in the word could be rendered other than by employing its original sense. Thus there seems to have been no mistranslation, for the following reasons:
--The Moon completes its rotating motion on its own axis at the same time as it revolves around the Earth, i.e. 29.5 days (approx.), so that it always has the same side facing us.
--The Sun takes roughly 25 days to revolve on its own axis. There are certain differences in its rotation at its equator and
poles, (we shall not go into them here) but as a whole, the Sun is animated by a rotating motion.It appears therefore that a verbal nuance in the Qur'an refers to the Sun and Moon's own motion. These motions of the two celestial bodies are confirmed by the data of modern science, and it is inconceivable that a man living in the Seventh century A.D.--however knowledgeable he might have been in his day (and this was certainly not true in Muhammad's case)--could have imagined them. This view is sometimes contested by examples from great thinkers of antiquity who indisputably predicted certain data that modern science has verified. They could hardly have relied on scientific deduction however; their method of procedure was more one of philosophical reasoning. Thus the case of the Pythagoreans is often advanced. In the Sixth century B.C., they defended the theory of the rotation of the Earth on its own axis and the movement of the planets around the Sun. This theory was to be confirmed by modern sciece. By comparing it with the case of the Pythagoreans,it easy to put forward the hypothesis of Muhammad as being a brilliant thinker, who was supposed to have imagined all on his on his own what modern science was to discover centuries later. In so doing however, people quite simply forget to mention the other aspect of what these geniuses of philosophical reasoning produced, i.e. the colossal blunders that litter their work. it must be remembered for example, that the pythagoreans also defended the theory whereby the Sun was fixed in space; they made it the centre of the world and only conceived of a celestial order that was centered on it.
It is quite common in the works of the great philosophers of antiquity to find a mixture of valid and invalid ideas about the Universe. The brilliance of these human works comes from the advanced ideas they contain, but they should not make us over look the mistaken concepts which have also been left to us. From a strictly scientific point of view, this is what distinguished them from the Qur'an. In the latter, many subjects are referred to that have a bearing on modern knowledge without one of them containing a statement that contradicts what has been established by present-day science.
The Sequence of Day and Night.
At a time when it was held that the Earth was the centre of the world and that the Sun moved in relation to it, how could any one have failed to refer to the Sun's movement when talking of the sequence of night and day? This is not however referred to in the Qur'an and the subject is dealt with as follows:
--sura 7, verse 54:
"(God) covers the day with the night which is in haste to follow it..."
--sura 36, verse 37:
"And a sign for them (human beings) is the night. We strip it of the day and they are in darkness."
--sura 31, verse 29:
"Hast thou not seen how God merges the night into the day and merges the day into the night."
--sura 39, verse 5:
"...He coils the night upon the day and He coils the day upon the night."
The first verse cited requires no comment. The second simply provides an image. It is mainly the third and fourth verses quoted above that provide interesting material on the process of interpenetration and especially of winding the night upon the day and the day upon the night. (sura 39, verse 5)
'To coil' or 'to wind' seems, as in the French translation by R. Blachere, to be the best way of translating the Arabic verb kawwara. The original meaning of the verb is to 'coil' a turban around the head; the notion of coiling is preserved in all the other senses of the word. What actually happens however in space? American astronauts have seen and photographed what happens from their spaceships, especially at a great distance from Earth, e.g. from the Moon. They saw how the Sun permanently lights up (except in the case of an eclipse) the half of the Earth's surface that is facing it, while the other half of the globe is in darkness. The Earth turns on its own axis and the lighting remains the same, so that an area in the form of a half-sphere makes one revolution around the Earth in twenty-four hours while the other half-sphere, that has remained in darkness, makes the same revolution in the same time. This perpetual rotation of night and day is quite clearly described in the Qur'an. It is easy for the human understanding to grasp this notion nowadays because we have the idea of the Sun's (relative) immobility and the Earth's rotation. This process of perpetual coiling, including the interpenetration of one sector by another is expressed in the Qur'an just as if the concept of the Earth's roundness had already been conceived at the time-which was obviously not the case.
Further to the above reflections on the sequence of day and night, one must also mention, with a quotation of some verses from the Qur'an, the idea that there is more than one Orient and one Occident. This is of purely descriptive interest because these phenomena rely on the most commonplace observations. The idea is mentioned here with the aim of reproducing as faithfully as possible all that the Qur'an has to say on this subject. The following are examples:
--In sura 70 verse 40, the expression 'Lord of Orients and Occidents'.
--In sura 55, verse 17, the expression 'Lord of the two Orients and the two Occidents'.
--In sura 43, verse 38, a reference to the 'distance between the two Orients', an image intended to express the immense size of the distance separating the two points. Anyone who carefully watches the sunrise and sunset knows that the Sun rises at different point of the Orient and sets at different points of the Occident, according to season. Bearings taken on each of the horizons define the extreme limits that mark the two Orients and Occidents, and between these there are points marked off throughout the year. The phenomenon described here is rather commonplace, but what mainly deserves attention in this chapter are the other topics dealt with, where the description of astronomical phenomena referred to in the Qur'an is in keeping with modern data.