the sequence of day and night!
at a time when it was held that the earth was the centre of the world and that 
the
sun moved in relation to it, how could any one have failed to refer to the
sun's movement when talking of the sequence of night and day? this is not
however referred to in the qur'an and the subject is dealt with as follows:
--sura 7, verse 54: "(god) covers the day with the night which is in
haste to follow it..."
--sura 36, verse 37: "and a sign for them (human beings) is the night.
we strip it of 
the
day and they are in darkness." --sura 31, verse 29: "hast thou
not seen how god merges the night into the day and merges the day into the
night."
--sura 39, verse 5:
"...he coils the night upon the day and he coils the day upon the
night."
the first verse cited requires no comment. the second simply provides an image.
it is mainly the third and fourth verses quoted above that provide interesting
material on the process of interpenetration and especially of winding the night
upon the day and the day upon the night. (sura 39, verse 5)
'to coil' or 'to wind' seems, as in the french translation by r. blachere, to
be the best way of translating the arabic verb kawwara. the original meaning of
the verb is to 'coil' a turban around the head; thenotion of coiling is
preserved in all the other senses of the word. what actually happens however in
space? american astronautshave seen and photographed what happens from their
spaceships, especially at a great distance from earth, e.g. from the moon. they
saw how the sun permanently lights up (except in the caseof an eclipse) the
half of the earth's surface that is facing it, while the other half of the
globe is in darkness. the earth turnson its own axis and the lighting remains
the same, so that an area in the form of a half-sphere makes one revolution
around the earth in twenty-four hours while the other half-sphere, thathas
remained in darkness, makes the same revolution in the same time. this
perpetual rotation of night and day is quite clearlydescribed in the qur'an. it
is easy for the human understanding to grasp this notion nowadays because we
have the idea of thesun's (relative) immobility and the earth's rotation. this
process of perpetual coiling, including the interpenetration of one sector by another
is expressed in the qur'an just as if the concept of the earth's roundness had
already beenconceived at the time-which was obviously not the case. further to
the above reflections on the sequence of day andnight, one must also mention,
with a quotation of some verses from the qur'an, the idea that there is more
than one orient and one occident. this is of purely descriptive interest
becausethese phenomena rely on the most commonplace observations. the idea is
mentioned here with the aim of reproducing as faithfully as possible all that
the qur'an has to say on this subject. the following are examples:
--in sura 70 verse 40, the expression 'lord of orients andoccidents'.
--in sura 55, verse 17, the expression 'lord of the two orients and the two
occidents'.
--in sura 43, verse 38, a reference to the 'distance between the two orients',
an image intended to express the immense size ofthe distance separating the two
points. anyone who carefully watches the sunrise and sunset knowsthat the sun
rises at different point of the orient and sets at different points of the
occident, according to season. bearings taken on each of the horizons define
the extreme limits that markthe two
orients
and occidents, and between these there are points marked off throughout the
year. the phenomenon described here is rather commonplace, but what mainly
deserves attention in this chapter are the other topics dealt with, where the
description of astronomical phenomena referred to in thequr'an is in keeping
with modern data.
this is no less than a reminder to (all) the worlds. and you shall certainly
know the truth of it (all) after a while.(38:87-88).