Our galaxy, the milky way galaxy, includes one hundred billion stars situated in such a formation that the galaxy is shaped like a disc. This disc turns around its center like a gramophone record. Now, it is obvious that when a gramophone record turns, any point on the disc would move around and come back to its original position. Similarly, every star in the galaxy moves as the galaxy rotates on its axis. Therefore the stars that are away from the center of the galaxy orbit around the axis. The sun is one of those stars.
 

Dr. Bucaille explains that modern science has worked out the details of the sun's orbit as follows: "To complete one revolution on its own axis, the galaxy and the sun take roughly 250 million years. The sun travels roughly 150 miles per second in the completion of this" (The Bible, the Qur'an and Science, p. 162). After describing this, Dr. Bucaille comments:

Dr. Bucaille comments: "This shows just how incapable men were of understanding this concept of the sun's and moon's orbit." (The Bible, the Qur'an and Science, p. 161). 

From this it is clear that if the Qur'an was here expressing an idea already known to the people, the commentators would have easily understood it. But this, as Dr. Bucaille explains was "a new concept that was not to be explained until centuries later" (The Bible, the Qur'an and Science, p. 161) 

This confirms what God said to his prophet, on whom be peace: "This is of the tidings of the Unseen which we inspire in you (Muhammad). Neither you nor your people knew it before this" (Qur'an 11:49). 
 
 

THE SUN & MOON MOVE WITH THEIR OWN MOTION
 

The Qur'an makes the following statement about the sun and the moon: "Each one is travelling in an orbit with its own motion" (Qur'an 21:33; 36:40).  Why did the Qur'an say that the sun and moon move with their own motion? And, if that is true, where did the author of the Qur'an get this information? The fact is that the sun and moon rotate on their axes and are in part animated by this rotating motion.

 The phrase "travelling with its own motion" in the verses quoted above is a translation of the Arabic verb 'yasbahoon'. This could also be translated 'they swim.' In that case, the verse would read that the sun and the  moon, "Each swim in its own orbit." Those who translate the verse this way explain that the term swim refers to movement with one's own internally generated force. Furthermore the movement of a swimmer is graceful, measured, and smooth. This is a very fitting description for the movement of the stars and planets including the sun and the moon. 
After describing the scientific data concerning the rotation of the sun and the moon, Dr. Bucaille says: "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.... could have imagined them" (The Bible, the Qur'an and Science, p. 163). 

It is also amazing that the Qur'an uses a different term for the movement of the clouds and the mountains (see Qur'an 27:88). Obviously, the clouds and mountains are driven by external forces. The cloud is driven by the wind and the mountains move with the rotation of the earth. The sun and moon, however, move with their own motion, and therefore the Qur'an uses a peculiar term "they swim" to refer to their smooth, graceful, self-propelled movement. 

How did the author of the Qur'an know enough to make this choice of words that will reflect a modern scientific truth? The Qur'an is no less than a revelation from God. 
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, Sec-ond 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. 

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, im- practical 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 in 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. 

  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.