It's not a question of whether mankind had proved these facts or not. The Qur'an hadn't proved them either, it had simply alluded to them in vague verses.
The thing is that these 'facts' whether actually proved by mankind or not, had certainly been known about, discussed and written down before the Qur'an had ever been thought about.
The thing is that these 'facts' whether actually proved by mankind or not, had certainly been known about, discussed and written down before the Qur'an had ever been thought about.