If Muslims suggest that the understanding of science shown by their prophet Muhammad is so profound as to be supernatural, then they must accept that if Muhammad gets any science wrong, then he cannot be a messenger from God.
There are two particular statements which fall into my area of expertise:
1)where sperm/semen comes from
2) how many joints there are in the body
I will deal with the latter first as it is easier to deal with
“Aisha reported Allah’s Messenger (may peace be upon him) as saying: Every one of the children of Adam has been created with three hundred and sixty joints; so he who declares the Glory of Allah, praises Allah, declares Allah to be One, Glorifies Allah, and seeks forgiveness from Allah, and removes stone, or thorn, or bone from people’s path, and enjoins what is good and forbids from evil, to the number of those three hundred and sixty-four, will walk that day having removed himself from Hell. (Translation of Sahih Muslim, The Book of Zakat (Kitab Al-Zakat), Book 005, Number 2199)”
Narrated Buraydah ibn al-Hasib: “I heard the Apostle of Allah peace_be_upon_him) say: A human being has three hundred and sixty joints for each of which he must give alms. The people asked him: Who is capable of doing this? He replied: It may be mucus in the mosque which you bury, and something which you remove from the road; but if you do not find such, two rak’ahs in the forenoon will be sufficient for you. (Translation of Sunan Abu-Dawud, General Behavior (Kitab Al-Adab), Book 41, Number 5222)”
This is undeniably and provenly wrong. Even more revealing, we find that Chinese philosophers said there were 360 joints in the body. So we see that “Muhammad” had an earthly fallible source for his “amazing knowledge”.
We find in the Koran this:
“Now let man but think from what he is created! He is created from a drop emitted - Proceeding from between the backbone and the ribs:” S. 86:5-7
This also is very definitely not true! As everyone knows, the spermatazoa come from the testes, and the semen is produced by the addition of fluid from the seminal vesicles and the prostate. Nowhere near the ribs!
So again Mohammed is proved wrong!
So Mohammed did not hear from God, but the deceiver, the Father of Lies, the fallen angel, Lucifer himself.