After the Big Bang the universe was primarily Hydrogen, Helium and a tiny bit of Lithium. However when a gas is too hot it becomes ionized (loses the electrons) and becomes opaque (like today's smoke). In the beginning the universe was opaque to visible light (non-transparent). After 380,000 years the universe cooled enough and it became transparent to visible light. For other wavelengths it was opaque for a billion years. So "Let there be light" turned out to be false. However the Quran correctly said that at the beginning it was SMOKE, that is, a hot non-transparent gas:
[Quran 41.11] Then He directed himself to the Heaven when it was SMOKE, and then said to it and to Earth: "Come willingly or by force" they said "We do come willingly"
How could an illiterate man who lived 1400 years ago have known that it was just smoke after the Big Bang?
The universe was created in a Big Bang 13.7 billion years ago, is still expanding today, and billions of years from now it might recollapse by its own gravity with a Big Crunch (or continue expanding forever, Big Chill). Moslems say that this is what Allah says. The Quran says that on the first day of creation, God made the heavens and the Earth meshed together, tight and compact (Big Bang), continues to expand it into the universe we know today and at the last day God will recompress it into its original state (Big Crunch). About the first day (Big Bang), Allah says:
[Quran 21.30] Do not those who disbelieve see that the heavens and the Earth were meshed together then We ripped them apart? And then We made of water everything living? Would they still not believe?
In the Quran the Heavens expanded from a single point.
Cosmologists just confirmed the existence of "Dark Energy", a mysterious repulsive force that acts in opposite to gravity. As the distance increases, the attractive gravitational force decreases but this mysterious repulsive force increases. This repulsive force is pushing galaxies apart; the greater the distance the greater the repulsion. Scientists today do not know what this "Dark Energy" is, but they know that it is causing the entire universe to expand at an increasing rate.
[Quran 51.47] And the heaven, We built it with craftsmanship and We are still expanding.
The Quran told us about this expansion 1400 years before it was discovered.
There are three possibilities to how the universe could end: Big Crunch (Quran), Big Chill and the Big Rip. NASA recently ruled out the third scenario (No Big Rip; see also: Universe Today). This leaves the universe with only two possible endings: Big Chill or Big Crunch, depending on what this Dark Energy turns out to be. Learn more: Expansion of Universe in Quran. In the Quran God promises to make the Big Crunch:
[Quran 21.104] On the day when We will fold the heaven, like the folder compacts the books, and as We originated the first creation We shall return it; a promise (binding on Us); surely We will deliver.
Here God promises to make this Big Crunch however not by gravity but rather by folding the Heavens like a book, that is, by the same mechanism He controls wormholes. This means that this Big Crunch can begin and end in a fraction of a second!
Also after this Big Crunch is over, God promises to recreate those heavens and Earth once more before Judgment Day:
[Quran 14.48] On the day when Earth will be swapped by another Earth and so will be the heavens; and all (creatures) will resurrect before the One Dominant God.
[Quran 36.81] Is He not, who created the heavens and the Earth, capable of creating others like them? Yes, indeed! He is the All-Knowing Creator. His command, if He wanted a thing, is that He only says to it, "BE" and it becomes! So glorified is He in whose hands is the dominion of all things, and to Him you shall be returned.