I agree with nj7 to some extent. To look for the source of this nonsense is to tacitly accept that the nonsense is sufficiently impressive so as to be worth looking for a possible source. It isnt really worth it, because there isnt anything impressive in the quran.
However, there are at least 2 reasons why it could be a good approach.
1. forcing the muslim to face the logical conclusion of his argument: that Aristotle (for example) must therefore be a prophet.
2. to show that the words and concepts similar to those in the quran have throughout history, been used to reference something utterly unscientific. For example, we could show that the quranic verse allegedly referring to the big bang, can very easily be understood in the context of pre Islamic creation myths where the sky (often a physical dome) was seperated from the (flat) earth and raised up to become 'the blue bit at the top'.
Egyptian
Ra seperated the eath from sky by placing the air god Shu between the sky god Nut, and the earth god Geb.
Greek
The earth (Gaia) gives birth to the sky (Uranus)
Babylonian
Marduk splits the corpse of Tiamat into two parts. the heavens and the earth.
Indian
Brahma is born in an egg, A year later, he splits the egg into two halves which become the heaven and earth
Chinese
Pan Gu is hatched from a cosmic egg. Half the shell is above him as the sky, the other half below him as the earth
Norse
Odin and his brothers kill Ymir. they split his body and making the earth from his flesh, and the heavens from his skull.
Maori
"It is by the strength of Tane that the sky and Earth were separated, and Light was born."
Sumerian
"After heaven had been moved away from earth,
After earth had been separated from heaven,
After the name of man had been fixed;"
As for the moon being reflected light, I think Hassan had a video explaining that it simply does not say that.
But to answer the actual question, the Greeks knew it anyway. They understood what an eclipse was. This requires knowledge that the moon reflects the sun's light
from wiki: "The ancient Greek philosopher Anaxagoras (d. 428 BC) reasoned that the Sun and Moon were both giant spherical rocks, and that the latter reflected the light of the former.[117][118] Although the Chinese of the Han Dynasty believed the Moon to be energy equated to qi, their 'radiating influence' theory also recognized that the light of the Moon was merely a reflection of the Sun,"
Topic: Scientific miracles: source of possibility