सिद्धान्तशिरोमणि: गणिताध्याय (भास्कराचार्य - ग्रहगणित, मध्यमाधिकार व स्पष्टाधिकार सटीक)

MADHYĀDHIKĀRA - KAKSHĀDHYĀYA
Verses 1, 2. The circumference of Akāsa---Kakshā.
Astronomers say that the circumference of Akāsa-
Kaksha is 18712069200000000 yojanas. Some say it is the
circumference of the universe whereas some say that it is
the circumference of the mountain which goes by the name
Lokāloka. Those who perceive the celestial sphere as a
fruit of the emblic myrobalan, (Known as Āmalaka in Sans-
krit) placed in the palm, say that it is the circumference of
the sphere of solar radiation ie the imaginary sphere whose
volume is filled by solar light.
Comm. Bhāskara, in the course of the Commentary
makes it clear that he does not subscribe to this idea which
is only mythological. Look at his words which are signifi-
cant and testify to his rational outlook “नाऽस्माकं मतमित्यर्थः,
प्रमाण शून्यत्वात्” ie “This is not our view; because it is
baseless”. A yojana will be seen to be equal to 5 miles
approximately.
Verse 3. He gives his personal view as follows.
The universe may be bounded or unbounded; our view
is that this dimension of the circumference is no other
than the distance covered by each planet in the Kalpa.
Comm. This was an assumption made by the ancient
Hindu Astronomers, as well as another assumption that the
distance covered by every planet during a day is the same.
This we shall see later.
Verse 4. The circumference of the universe given
above divided by the number of the sidereal revolutions in
a Kalpa of any planet gives the circumference of the plane-
tary orbit, so that in a Kalpa, the total distance covered is
the circumference of the universe.