Difference between Dhiyaa’ and Noor
1-2-2010 | IslamWeb
Question:
Salamalaikum its like i wanted to know the meaning of noor.is it reflected light or just light???? can a muslim keep his name as moinullah.........may allah reward you
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
The naming of the rays of the sun are mentioned in the Quran as Dhiyaa’ (shining light) and the rays of the moon are called Noor (reflected light). Recently, one researcher on scientific miraculousness [of the Quran] tried to find out the secret of this difference in wording and he said: “If we try to remember the information we learned about physics during our school days, we would find that the source of light is generally divided into two categories: Direct sources, like the sun, the stars, the lamp, the candle, and so forth, and indirect sources like the moon and the planets. This last category are the bodies that take its light from another source like the sun and then it reflects it [light] to us. As regards the sun and the lamp, they share the same characteristic, which is that they are considered as a direct source of light. It is for this reason that Allaah resembled the sun to the shining lamp and He did not resemble the moon as a lamp in any verses. Also, Allaah called the rays that the sun diffuses as Dhiyaa’. However, the moon does not have the same quality like them. The moon is an indirect source of light, it reflects the light of the sun to us, so we see it and we see its rays which Allaah, the All-Knowledgeable and the All-Wise named as Dhiyaa’.”
Therefore, the Noor is the reflected light. Moreover, we found that Al-Aloosi 
stated in his interpretation of the Quran that such a difference in wording is also discussed by whom he called as the Islamists among the philosophers, like Ibn Sina (Avicinna), Al-Faraabi (Alpharabius) and so forth.
As regards the second question, it is not permissible – Allaah Knows best – to be named with the name ‘Mu’eenu Allaah’ as it has a wrong meaning, which means that Allaah is incapable and He needs someone to help Him, while Allaah Says about Himself (what means): {…nor is there for Him from among them any assistant.}[Quran 34:22], which means that He has no assistant from among His Creation. For more benefit on the conditions of naming children, please refer to Fataawa 87262 and 82724.
If the person whom you mentioned in the question wanted a correct meaning derived from this word, he would call himself Al-Musta’een Billaah, or Mu’aan Allaah, which means the one who seeks the Help of Allaah, and this is acceptable religiously and linguistically.
Allaah Knows best.