Many adversaries of the Quran criticize the scientific merit of the following verses.
[86:5] Let the human reflect on his creation. [86:6] He was created from ejected liquid. [86:7] From between the spine and the viscera.
Their argument against these verses is that the semen does not originate between the spine and the viscera, therefore this verse is scientifically false. But the error is not in the verse, but in their understanding.
The word that the Quran uses for semen is نُطْفَةٍ. This word is typically translated as “semen” or “tiny drop”. See 18:37, 22:5, 23:13, 35:11, 36:77, 40:67, 53:46, 80:19.
[16:4] He created the human from a tiny drop, then he turns into an ardent opponent.
خَلَقَ الْإِنْسَانَ مِنْ نُطْفَةٍ فَإِذَا هُوَ خَصِيمٌ مُبِينٌ
The other word that is used for semen is مَنِيٍّ
[75:37] Was he not a drop of ejected semen?
أَلَمْ يَكُ نُطْفَةً مِنْ مَنِيٍّ يُمْنَىٰ
But 86:6 does not use either the word نُطْفَةٍ or مَنِيٍّ. Instead, it uses the word مَاءٍ which means water or liquid. You will see this word used in the context of reproduction in the following verse as well:
[32:8] Then He continued his reproduction through a certain lowly liquid.
ثُمَّ جَعَلَ نَسْلَهُ مِنْ سُلَالَةٍ مِنْ مَاءٍ مَهِينٍ
But there is one other word that is used that will help clarify this matter for us, that can be found in 76:2.
[76:2] We created the human from a liquid mixture, from two parents, in order to test him. Thus, we made him a hearer and a seer.
إِنَّا خَلَقْنَا الْإِنْسَانَ مِنْ نُطْفَةٍ أَمْشَاجٍ نَبْتَلِيهِ فَجَعَلْنَاهُ سَمِيعًا بَصِيرًا
The Arabic uses the term نُطْفَةٍ which means tiny drop or semen, followed by the word أَمْشَاجٍ which means mixture. This makes sense as obviously a human is not created from just semen alone, but the mixture of semen plus the contents inside a women. This is further reinforced when it clarifies that the mixture is “from two parents.”
Therefore, when the term مَاءٍ (liquid / water) is used in the Quran, in the context of reproduction, it is understood to be from inside a women. This makes sense as the amniotic fluid that holds the developing child is also commonly called water, even in English. This expression is used when the amniotic sac bursts before delivery and we say that “her water broke.”
Additionally, if we read the Arabic of 86:6 it states:
خُلِقَ مِنْ مَاءٍ دَافِقٍ
The term دَافِقٍ means to pour forth or to pour out and is typically used for water or contents.
Therefore 86:6-7 is not in reference to semen, but it is identifying that a human is created between the spine and the viscera of a woman during pregnancy. And the human comes to this world through liquid poured out from the amniotic fluid. Now that this is clarified, I think a person would be hard-pressed to object to such a fact, even if that person is a disbeliever.