After the Big Bang it was all smoke.
The Christian Bible says that in the beginning God said "Let there be light" (Genesis 1:3). However this turned out to be false. After the Big Bang the universe was opaque and photons couldn't travel at all.
About 300,000 years after the big bang, the universe was like a smoke-filled chamber from which light could not escape. By the time the universe was a billion years old, the smoke - actually a gas of light-trapping hydrogen - had cleared almost entirely, allowing stars and galaxies to become visible. But exactly what cut through the haze has been one of the big questions in astrophysics. Now, by analyzing images taken by the Hubble Space Telescope, researchers have come close to confirming their best guess: the smoke was cleared away by a blaze of ultraviolet radiation from the earliest galaxies.
Science, How the Early Universe Cleared Away the Fog, 2010
The first 380,000 years the universe was opaque to visible light (non-transparent) and photons couldn't travel at all. Few minutes after the Big Bang the universe was primarily Hydrogen, Helium and a tiny bit of Lithium and Beryllium. But 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. It took 380,000 years for the universe to cool enough, and only then it became transparent to visible light. For other wavelengths it was opaque for a billion years.
So "Let there be light" of the Bible turned out to be false. However the Quran correctly said that in 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 in the beginning it was all smoke?