It is often claimed by Islamic apologists that Quran explains the "creation" of Universe in a miraculously correct manner. Muslims often claim that Quran explains the Big Bang theory correctly despite being written over 1400 years ago. This is one of the most commonly cited "Scientific miracles of the Quran". However, a careful look at the verses of the Quran shows something entirely different. Apart from the fact that it doesn't explain the big bang, the Quran also appears to contradict it, and makes claims that go against basic scientific knowledge of the universe.
The following verse is the base of the Islamic claim:
21:30 - Have not those who disbelieve known that the heavens and the earth were joined together as one united piece, then We parted them? And We have made from water every living thing. Will they not then believe?
This is allegedly referred to as an explanation of the big bang. The fact is though that apart from claiming that Earth and "heavens" (it is claimed that the heavens refers to the rest of the universe) were together, there is nothing that remotely matches big bang here. The verse also inaccurately claims that the Earth was "separated" or "parted" from the heavens. This is a troublesome claim because the Earth didn't even exist until BILLIONS of years after the big bang. Imagine how grossly inaccurate the verse is. But of course the apologists don't give up just like that. They say that the verse doesn't really claim the Earth existed in its current form when the separation happened. This doesn't sound convincing at all and if that was a description of the big bang, then it is the worst possible description I have ever read. Let's look at another part of the Quran to see some more claims it makes about the universe.
41:10 - He placed therein (i.e. the earth) firm mountains from above it, and He blessed it, and measured therein its sustenance (for its dwellers) in four Days equal (i.e. all these four 'days' were equal in the length of time), for all those who ask (about its creation).
41:11 - Then He Istawa (rose over) towards the heaven when it was smoke, and said to it and to the earth: "Come both of you willingly or unwillingly." They both said: "We come, willingly."
41:12 - Then He completed and finished from their creation (as) seven heavens in two Days and He made in each heaven its affair. And We adorned the nearest (lowest) heaven with lamps (stars) to be an adornment as well as to guard (from the devils by using them as missiles against the devils). Such is the Decree of Him the All-Mighty, the All-Knower.
Look at the order of creation here. First Allah made the Earth, then he placed mountains and things for sustenance of life. Then he rose towards the heaven when it was nothing but a puff of smoke. Then he shaped them into seven heavens and made stars to decorate and "guard" the lowest heaven. These verses clearly claim that the Earth was formed before the stars, no matter how you look at it. This is in direct conflict with science. Science tells us that stars were formed billions of years before the formation of Earth.
CONCLUSION: The Quran makes huge scientific errors in its verses describing the universe and the claim of "scientific miracle" is an absolute joke. These are things that should become clear to anyone who has a basic understanding of what big bang and science tells us about the timeline of universe.