The Barrier Between Two Seas

The Quran states in 55:19-20: "He has let free the two bodies of flowing water, meeting together: Between them is a Barrier which they do not transgress."

Modern oceanography proves that when two seas meet, a barrier (halocline) forms due to density differences, preventing complete mixing.

Sources:
• Quran 55:19-20
• Quran 25:53
• NOAA: Ocean Fronts

Great Islamic commentators including Allamah Tabatabai in Al-Mizan and Ayatollah Makarem Shirazi in Tafsir Nemuneh have considered this verse as a reference to the continuous expansion of the universe. The word "lamūsiʿūn" comes from the root "awsa'a" meaning to expand and is in the intensive form, indicating the continuity of this expansion.

This article claims that the Holy Quran, more than 1400 years ago, referred to the scientific fact of the expansion of the universe; a fact that humanity only achieved in the 20th century through Edwin Hubble's observations.

The following scientific evidence supports this claim:

In the 7th century CE, the common belief was that the universe was static and eternal. Aristotle and Ptolemy had presented the geocentric model, and this belief continued until the 16th century and the Copernican revolution. In 1929, Edwin Hubble proved through his observations that galaxies are moving away from each other.

Based on scientific and Quranic evidence, it can be concluded that the Holy Quran has remarkably referred to scientific facts that were discovered centuries later. This harmony is a sign of the miracle of the Quran and an invitation to reflect on the divine verses.