Part 1 - On sun-rise and sun-set

In that period, at that time, there was a capital-city named Campā. Description. Outside the city of Campā, there was a caitya named Pūrṇabhadra. Description. Śramaṇa Bhagavān Mahāvīra came,...till the people dispersed.

In that period, at that time, Śramaṇa Bhagavān Mahāvīra had a senior-most disciple in a monk named Indrabhūti who belonged to the Gautama line,...dll he made the following submission:

Q. 1. Bhante! In the isle called Jambūdvīpa, does the sun rise in the north-east and set in in the south-east? Does it rise in the south-east and set in in the south-west? Does it rise in the south-west and set in in the north-west? Does it rise in the north-west and set in in the north-east?

A. 1. Yes, Gautama, the sun rises in the north-east,...till comes back to the north-east¹.

Q. 2. Bhante! When it is day in the southern portion of the isle named Jambūdvīpa, is it also day in the northern portion? And when it is day in the northern portion, is it night in the east and the west of Mount Meru in the isle named Jambūdvīpa?

A. 2. Yes, Gautama, when it is day in the southern portion of the isle named Jambūdvīpa,...till it is night, etc.

Q. 3. Bhante! When it is day in the east of Mount Meru in the isle called Jambūdvīpa, is it also day in the west? And when it is day in the west, then, is it night in the north and in the south of Mount Meru in the isle named Jambūdvīpa?

A. 3. Yes, Gautama, when it is day in the east of Mount Meru in the isle named Jambūdvīpa,...till it is night, etc.

Notes (based on commentary of Abhayadeva Sūri):

1. The rising and the setting of the sun in particular directions is only relative to our vision. The reality is that the sun is all the time on this earth, but when our vision is obstructed, we do not see the sun, and then we say, ‘the sun has set’. But just at that time when we do not see the sun, people in some other parts of this earth whose obstruction has been removed see the sun, and they say,‘the sun has risen’. Thus the rising and the setting of the sun are relative to our vision depending on whether the vision is obstucted or not.

As it has been said,

jaha jaha samaye samaye purao saṃcarai bhakkharo gayaṇe
taha taha io vi ṇiyamā jāyai rayaṇī ja bhāvattho
evaṃ ca sai ṇarāṇaṃ udayatthamaṇāiṃ hoṃti aṇiyayāiṃ
sayadesabhee kassai kinci vavadissai ṇiyaṃā

[As the sun moves forward in the sky, the sky in the rear becomes dark. So the rising and the setting of the sun depend on the movement of the sun. The rising and the setting of the sun are not uniform phenomena in relation to man, but differ according to his geographical location.]

The Sūtta [Sūta?] establishes that the sun moves in all directions in the sky. This rejects the common-sense view, ordinarily held that the sun rises in the east and sets in the west. If still we observe the night and the day, it is because of the fact that the rays of the sun reach upto a certain distance only, and the region beyond that distance remains dark.

In the Jaina view, there are two suns over the Jambū-dvīpa because of which there is simultaneous day in the north and the south on one side of it and simultaneous night in the north and the south on the other side of it, and vice versa. Had there been only one sun, it would have served only half of one side at a time, say, the north, on this side, and then the other three, viz., the south on this side, and both the north and the south on the other side, would be without the sun. The terms uttarārdha and dakṣinārdha [dakṣiṇārdha?] do not signify that one is above the other, but are the two directions of the globe; nor does the suffix ardha mean half, but it means ‘only’.