na vai maharaja bhagavato maya-guna-vibhuteh kastham manasa vacasa vadhigantum alam vibudhayusapi
purusas tasmat pradhan-yenaiva bhu-golaka-visesam nama-rupa-mana-laksanato vyakhyasyamah.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The great rsi Sukadeva Gosvami said: My dear King, there is no limit to the expansion of the Supreme Personality of Godhead’s material energy. This material world is a transformation of the material qualities [sattva-guna, rajo-guna and tamo-guna], yet no one could possibly explain it perfectly, even in a lifetime as long as that of Brahma. No one in the material world is perfect, and an imperfect person could not describe this material universe accurately, even after continued speculation. O King, I shall nevertheless try to explain to you the principal regions, such as Bhuloka, with their names, forms, measurements and various symptoms.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The material world is only one fourth of the Supreme Personality of Godhead’s creation, but it is unlimited and impossible for anyone to know or describe, even with the qualification of a life as long as that of Brahma, who lives for millions and millions of years. Modern scientists and astronomers try to explain the cosmic situation and the vastness of space, and some of them believe that all the glittering stars are different suns. From Bhagavad-gita, however, we understand that all these stars (naksatras) are like the moon, in that they reflect the sunshine. They are not independent luminaries. Bhuloka is explained to be that portion of outer space through which the heat and light of the sun extend. Therefore it is natural to conclude that this universe extends in space as far as we can see and encompasses the glittering stars. Srila Sukadeva Gosvami admitted that to give full details of this expansive material universe would be impossible, but nevertheless he wanted to give the King as much knowledge as he had received through the parampara system. We should conclude that if one cannot comprehend the material expansions of the Supreme Personality of Godhead, one certainly cannot estimate the expansiveness of the spiritual world. The Brahma-samhita (5.33) confirms this:
advaitam acyutam anadim ananta-rupam
adyam purana-purusam nava-yauvanam ca
The limits of the expansions of Govinda, the Supreme Personality of Godhead, cannot be estimated by anyone, even a person as perfect as Brahma, not to speak of tiny scientists whose senses and instruments are all imperfect and who cannot give us information of even this one universe. We should therefore be satisfied with the information obtainable from Vedic sources as spoken by authorities like Sukadeva Gosvami.