Tidal Locking

The Quran often cites scientific facts embedded in its verses. For instance, the Quran describes the orbit of planets when it makes the statement, “each floating in its own orbit” ( كُلٌّ فِي فَلَكٍ يَسْبَحُونَ ).

[36:40] The sun is never to catch up with the moon—the night and the day never deviate—each of them is floating in its own orbit.

(٤٠) لَا الشَّمْسُ يَنْبَغِي لَهَا أَنْ تُدْرِكَ الْقَمَرَ وَلَا الَّيْلُ سَابِقُ النَّهَارِ وَكُلٌّ فِي فَلَكٍ يَسْبَحُونَ

[21:33] And He is the One who created the night and the day, and the sun and the moon; each floating in its own orbit.

(٣٣) وَهُوَ الَّذِي خَلَقَ الَّيْلَ وَالنَّهَارَ وَالشَّمْسَ وَالْقَمَرَ كُلٌّ فِي فَلَكٍ يَسْبَحُونَ

What is interesting about this statement is the expression كُلٌّ فِي فَلَكٍ (each in its orbit) is a palindrome. This means the statement is the same if read forwards or backward, such that the letters are orbiting around one another.

In the following verse, the Quran describes that one of God’s signs is that length of our shadows is determined by the sun.

[25:45] Have you not seen how your Lord designed the shadow? If He willed, He could have made it fixed, then we would have designed the sun accordingly.
[25:46] But we designed it to move slowly.

(٤٥) أَلَمْ تَرَ إِلَىٰ رَبِّكَ كَيْفَ مَدَّ الظِّلَّ وَلَوْ شَاءَ لَجَعَلَهُ سَاكِنًا ثُمَّ جَعَلْنَا الشَّمْسَ عَلَيْهِ دَلِيلًا
(٤٦) ثُمَّ قَبَضْنَاهُ إِلَيْنَا قَبْضًا يَسِيرًا

Tidal locking between a pair of co-orbiting astronomical bodies occurs when one of the objects reaches a state where there is no longer any net change in its rotation rate over the course of a complete orbit. In the case where a tidally locked body possesses synchronous rotation, the object takes just as long to rotate around its own axis as it does to revolve around its partner.

For example, the same side of the Moon always faces the Earth. That’s because the Moon is so close to our planet that the side facing us experiences a much stronger gravitational pull to Earth. And it takes the Moon just as long to make one rotation on its own axis as it does to make a full orbit around the Earth. That makes the Moon tidally locked to our planet.

If God wanted to make the shadow fixed on Earth, He could have made the Earth tidal locked to the Sun. This would cause one side of the Earth to be perpetually day and the other side would be perpetually night. Not only would the seasons be obliterated, but one side of Earth would be uninhabitable due to heat that would cause the oceans on that side to boil and vaporize. While the other side of Earth would be frozen in bitter darkness. These extreme temperature shifts would cause huge differences in atmospheric pressure, which would cause hellish storms all over the planet, and could potentially cause Earth to lose its atmosphere altogether.

[28:71] Say, “What if GOD made the night perpetual, until the Day of Resurrection? Which god, other than GOD, can provide you with light? Do you not hear?”
[28:72] Say, “What if GOD made the daylight perpetual, until the Day of Resurrection? Which god, other than GOD, can provide you with a night for your rest? Do you not see?”

(٧١) قُلْ أَرَأَيْتُمْ إِنْ جَعَلَ اللَّهُ عَلَيْكُمُ الَّيْلَ سَرْمَدًا إِلَىٰ يَوْمِ الْقِيَامَةِ مَنْ إِلَٰهٌ غَيْرُ اللَّهِ يَأْتِيكُمْ بِضِيَاءٍ أَفَلَا تَسْمَعُونَ
(٧٢) قُلْ أَرَأَيْتُمْ إِنْ جَعَلَ اللَّهُ عَلَيْكُمُ النَّهَارَ سَرْمَدًا إِلَىٰ يَوْمِ الْقِيَامَةِ مَنْ إِلَٰهٌ غَيْرُ اللَّهِ يَأْتِيكُمْ بِلَيْلٍ تَسْكُنُونَ فِيهِ أَفَلَا تُبْصِرُونَ

For Earth to become tidal locked to the Sun, it would have to move closer to the Sun, and its rotation would be slowed down to match the rotation of the Sun, which takes ~25 days, such that one side of the Earth would always face the Sun.

When we look at the verses, we see that this is what is being described for such an event to be carried out. It states:

وَلَوْ شَاءَ لَجَعَلَهُ سَاكِنًا ثُمَّ جَعَلْنَا الشَّمْسَ عَلَيْهِ دَلِيلًا
[25:45] If we willed, we could have made it stationary, then we (would have) made the sun a guide for it.

ثُمَّ قَبَضْنَاهُ إِلَيْنَا قَبْضًا يَسِيرًا
[25:46] then we (would have) withdrawn it to us, withdrawing gradually.

The word dalīlan ( دَلِيلًا ) used in this 25:45 means a guide or directory, while the root for the words qabaḍnāhu ( قَبَضْنَاهُ ) and qabḍan ( قَبْضًا ) used in 25:46 means to withdraw, grasp, or contract. This states that if God wanted to make the shadow fixed, he would have the Sun direct the Earth’s orbit which would pull the Earth closer to the sun and contract its orbit.

Here is the word-by-word breakdown.

أَلَمْ	Do not	alam
تَرَ	you see	tara
إِلَىٰ	to	ilā
رَبِّكَ	your Lord	rabbika
كَيْفَ	how	kayfa
مَدَّ	He extended / drew forth / cast	castmadda
الظِّلَّ	the shadow?	l-ẓila
وَلَوْ	And if	walaw
شَاءَ	He willed,	shāa
لَجَعَلَهُ	surely He could have made it	lajaʿalahu
سَاكِنًا	stationary / fixed.	sākinan
ثُمَّ	Then	thumma
جَعَلْنَا	we (would have) made	jaʿalnā
الشَّمْسَ	the sun	l-shamsa
عَلَيْهِ	for it	ʿalayhi
دَلِيلًا	a director / guide.	dalīlan
ثُمَّ	Then	thumma
قَبَضْنَاهُ	we contracted / withdrawn it	qabaḍnāhu
إِلَيْنَا	for us,	ilaynā
قَبْضًا	contracting / drawing	qabḍan
يَسِيرًا	easily / gradual / slow.	yasīran