You Must read part 7,6,5 before you read this.
One of our sisters drawn our attention that we considered the cosmic day: 24 hours and every hour is 3600 second, on what bases was that consideration? The answer is that is a human diligence and our objective is to understand the koranic signal about the speed of light , and the cosmic day may be not like that and also there maybe many signs in that Aya about another high cosmic speeds.
As our God be He blessed told us about the speed of the divine order and He be blessed associated it with the eye twinkling, God says: (And Our Commandment is n but one as the twinkling of an eye.)(Sûrat Al-Qamar – Aya 50). In another Aya which talks about the coming of the day of resurrection as that day will come so quickly, God says :( And to Allah belongs the Unseen of the heavens and the earth. And the matter of the Hour is not but as a twinkling of the eye, or even nearer. Truly! Allah is Able to do all things.)(Sûrat An-Nahl- Aya 77)
Also God says: (He manages and regulates (every) affair from the heavens to the earth; then it (affair) will go up to Him, in one Day, the space whereof is a thousand years of your reckoning (i.e. reckoning of our present world’s time))( Sûrat As-Sajdah- Aya5) and says in another Aya: (The angels and the Rûh [Jibrîl (Gabriel)] ascend to Him in a Day the measure whereof is fifty thousand years.)(Sûrat Al-Ma‘ârij-Aya 4)
The first one who demonstrated this idea is DR/ Mohamed Dodah in a published research in the website of "Commission on Scientific Signs of Qur'an & Sunnah"
The precise speed of light is : 299792.458 meter per second but we used the speed as: 299792 to facilitate calculations , with taking into consideration that usually the full speed of the light is in the empty space but the speed became much slower when penetrating liquids or glasses .
Moon Motion, http://www.aerospaceweb.org/
Speed of Light ,Wikipedia.
ON THE CONSTANCY OF THE SPEED OF LIGHT, www.ldolphin.org