Question: What does the following verse denote?
He is the Lord of two Easts and two Wests what is the meaning of this?[1]
Answer: In the Holy Qur’an the mention of East and West is done in the form of dual also. (i.e. two easts and two wests) and in the plural form of also e.g.
“But nay! I swear by the Lord of the Easts and the Wests that We are certainly able.”[2]
At one more place it is stated: “We gave the earth under the control of those people (i.e. organization (group) of Israelites), who had become weak and feeble.[3]
On this basis the words of East and West are used in the plural form also, which points out at numerous tenets. And in the dual form also which indicate towards two tenets.
The Commentators have given two meanings of those verses.
First is that two Easts and two Wests are two hemispheres (i.e. southern and northern or eastern and western). Some have considered this verse to be an indication to existence of one hemisphere (i.e. the great American continent before it was discovered, which is beyond the subject under discussion. In the same way by Easts and Wests is meant different points of the earth, in which every point with reference to one point is East, whereas the same point with reference to another point is West.
In other words, out of the peculiarities of the sphere, one is that its every point with reference to that point which is situated on its West side is counted as East and with reference to the point in front it is West. Therefore some people think that such verses are indication that the earth is round.
The other meaning is that Easts and Wests are many, that means the sun has so many points of its sunrise and sunset, because sun never rises and sets at the same point on any two days. And because of the Sun's inclination towards north and south (which is the result of the inclination of surface in relation to the moving earth around its axis and around the sun).
Sun rises everyday from one point and sets on the other. Therefore when we keep in mind the sum total of those Easts and Wests, then we should interpret them as the plural of easts and west. And when we keep in mind only the big northern inclination of sun to its last point (beginning of summer) and the big southern inclination's last point (beginning of winter), then we should interpret them as dual form of East and West.
This is the miracle of the Holy Qur’an that in a very short passage it draws the attention of people towards the astonishing mystery of creation.
Because we know that alterations in sunrise and sunset affect the nourishment and sustenance of foliage, flowers and fruits and generally on the common conditions of all living things and it has a deep effect on the decoration of the created world.

The Earth Being Spherical and the Holy Qur’an
Question: Is there evidence in the Holy Qur’an and traditions regarding the Earth being spherical?
Answer: Of the indications present in Qur’an regarding these mysteries is that the Earth is spherical. And this can be surmised from the following verses:
(1) And We made the people who were deemed weak to inherit the eastern lands and the western ones which We had blessed; and the good word of your Lord was fulfilled in the children of Israel because they bore up (sufferings) patiently…[4]
(2) The Lord of the heavens and the earth and what is between them, and Lord of the easts.[5]
(3) But nay! I swear by the Lord of the Easts and the Wests that We are certainly able to bring instead (others) better than them, and We shall not be overcome.[6]
Its explanation is this that, as indicated in the last discussion, this verse argues about Easts and Wests, and number of points of rising and setting of the sun, for which the earth should necessarily be spherical, because it is a universally admitted fact that if the earth had been flat there would have been only one East and one West. And only because the earth is round and inclined that every point of the earth can have a particular East and a separate West.
And the sun rising on a certain point from different points of the earth, just as sometimes it is necessary that it set on other part of the earth; therefore the Easts and Wests being many is clear proof of the earth being spherical.

Traditions regarding the earth being spherical
From the traditions that have come to us through the sinless Imams (a.s.) we can understand that the earth is spherical. One of such tradition from Imam as-Sadiq (a.s.) is given below:
Imam as-Sadiq (a.s.) said: In a journey, a man became a fellow traveler. He was habituated that he should pray the Evening Prayer in the darkness of the night, and pray the Morning Prayer in the complete darkness of the night (end of night).
But I was opposite to him. I used to pray the Evening Prayer when the sun set and perform the Morning Prayer at dawn break. He requested me to also pray in his manner and explained his act in this way: The sun before rising on our land rises on other places. And when it disappears from our land then too it shines on other places.
I told him: It is our practice that when the Sun disappears from our horizon, the Evening Prayer is prayed, and it is not necessary that we should wait for it to set in other places. And when the dawn breaks, we should pray the Morning Prayer, though the Sun may not have come out in other places. Because it is incumbent upon the people of all the places that they should offer their Prayers according to dawn and sunset of their horizons.[7]
Imam (a.s.) has described this fact in one more tradition: It is upon you that you should have the foundation of your deeds on your logical East and West.
And all this is said on the basis of the earth being spherical.

Rotation of the Earth
Question: Astronomers believe that the shape of the Earth is spherical and it revolves around its axis; is it confirmed by science or still undecided?
And if the Earth really revolves what are its scientific and perceptible signs?
What is the reason that the Polestar, by means of which direction of Qibla is ascertained, always shows up at the same location?
Other than this, is there any matter available in the Holy Qur’an and Islamic traditions that supports this?
Answer: In the present age it is scientifically proved that earth is spherical and it rotates around its axis and for this different arguments are given. The most evident proof of the movement of the earth is the “Proof of Pendulum”.
It is that if a heavy thing is hung with a rope that it can oscillate freely; when it is moved, it continues its movement for quite a long time. Now if the earth were immobile and without movement, then it is necessary that, the movement of the related thing should be up to a fixed line, but experience shows that the movement is not up to a fixed line and that it gradually moves away from the first line.
It is also known by this experience that the earth always moves from one fixed direction toward the other. The direction of this movement, which is from West to East, can be determined by the cause of lines. (For better understanding and explanation of this argument take the benefit of the books on astronomical science in which different sketches are present).
In the same way it is known by experience that if a stone is slowly left to fall from a height it does not fall in an exactly straight line but it falls slightly towards the West; and this shows that earth is moving from West to East.
Of course, what we see that the Polestar is always at one place, it is so because it is situated almost opposite to the axis of the earth. It is obvious that if a ball is turned round on its axis (for example a needle is pierced in the middle of an apple and the apple is rotated around the needle) then the point of the axis will always remain the same. For example the tip of the needle will always remain at the same place. That is reason that the polestar is always seen at one place.
As far as the behavior of earth is concerned, we should pay attention towards the point in front (lower part of the earth), since the shape of earth is almost like a ball. Wherever we go we will see its behavior as the same. That is we find the point above our head will be sky and the point below our feet will be earth and the gravitational pull keeps us on the land everywhere.
There are many stars, which are seen in the southern hemisphere and cannot be seen in the northern hemisphere and contrary to that planets also can be seen sometimes from one part and sometimes from other parts of the earth. The summary of this discussion is this that the logical behavior of the planet, which is opposite to us, is exactly like the one on which we live.
Following are some verses and traditions that support the theory of the rotation of the earth.
(1) And you see the mountains you think them to be solid, and they shall pass away as the passing away of the cloud - the handiwork of Allah who has made everything thoroughly.[8]
Sometimes it is considered that this verse has connection with Qiyamat. That man will see the mountains in that condition on the Day of Resurrection but the sentence; the handiwork of Allah who has made everything thoroughly, negates this, because this passage of writing is not concordant to the day of resurrection and the day of Qiyamat is not the day for Allah to be resolute; but it is the day when the Solar System would be destroyed. And at the end of the verse, Allah mentions the permanence of His creation in clear words not through the revolutionary changes, but it is denotes stability of the system.
The apparent meaning of the verse points out that the mountain is in motion, though they appear to be stationary and motionless. It is possible that here a question may be asked that why has Allah mentioned the movement of mountains instead of the movement of earth, whereas the movement of mountains is subordinate to the movement of earth? And wasn't it more appropriate that instead of (mentioning the) movement of the mountains the earth's movement were mentioned?
Nevertheless the answer to this question is clear, and it is that when a sphere rotates around its axis its movement is apparent by means of those teeth, and marks and paints, which are engraved on it. Other than that mountain is mentioned because it has always remained a sign of greatness and eminence and is a universally admitted fact that without the movement of the earth the movement of mountains does not have any meaning and sense.
One point worth attention is that instead of motionlessness, the word inertness is used, because this word, in this context is more according to the expression and the thought of the earth being stationary to express (regarding which the man gets engaged in misgivings) is more evident.
The reason Qur’an compares the movement of the mountains to the movements of clouds because the movement of the earth is just like the movement of clouds; being quiet, smooth and swift.
(2) (Allah) Who made the earth for you a cradle…[9]
The Holy Qur’an compares our earth to the cradle and it is possible that the reason of such comparison may be that the as the rocks softly in circulatory movement, the same is also the movement of the earth.

What Is The Exegesis of this Verse?
Question: What is the interpretation of the verse: Falaa uqsemo khunnasil jawaaril kunnase
But nay! I swear by the stars, that run their course (and) hide themselves?[10]
Answer: In the dictionary the meaning of Khunnas is one who returns and one who retreats. The meaning of Kunnas is one who gets concealed and Jaware is the plural of Jari (to continue, to flow) its meaning is the one who walks or moves.
As the verses before and after this verse show and the commentators also say that by these verses it is meant those planets, which can be seen (mercury, Venus, Mars, Jupiter and Saturn), because they are in motion, they appear sometimes and sometimes they disappear.
In the Holy Qur’an reference of those stars is given with an oath; and people's attention is drawn towards their special and distinct behavior and their movement and rotation and it calls attention towards the greatness of the Creator of the universe. This means, the type of those returning stars which moving and disappears.
We should also know that experts of astronomy have given those stars the name of “amaze stars” because, their movements are not on a straight line, and it seems that, they travel for certain period of time and then slightly they return, and again they continue their travel.
The reason of this behavior is discussed at length in the books of astronomy and it is possible that the indication of above-mentioned verses (which has mentioned about those stars in the style which are moving and coming back) may be towards these stars' capricious way (no doubt the way of this capricious travel has some logic which is beyond our comprehension at present).
Anyhow, these are the same wandering stars, whose special behavior makes them distinct.

Notes:
[1] Surah Rahman 55:17
[2] Surah Maarij 70:40
[3] Surah Aaraf 7:13
[4] Surah Aaraf 7:137
[5] Surah Saffaat 37:7
[6] Surah Maarij 70:40-41
[7] Wasailush Shia, Vol. I, p. 237
[8] Surah Naml 27:88
[9] Surah Taha 20:53
[10] Surah Takweer 81:15-16