Referring to the sun and the moon, the Qur'an tells us that both these heavenly bodies are moving in their own circular courses (falak) (36:40). Dr Maurice Bucaille, discussing these verses in detail, says that falak here has the scientific meaning of 'orbit,' while, 'floating' is the most appropriate term to describe the movement of celestial bodies in a vast and subtle space.

Dr Bucaille further writes:

It is shown that the sun moves in an orbit, but no indication is given as to what this orbit might be in relation to the Earth. At the time of the Qur'anic Revelation, it was thought that the Sun moved while the Earth stood still. This was the system of geocentrism that had held sway since the time of Ptolemy, in the second century B.C., and was to continue to do so until Copernicus in the sixteenth century A.D. Although people supported this concept at the time of Muhammad, it does not appear anywhere in the Qur'an, either here or elsewhere (p. 159).