All the pastimes of the Supreme Lord in the spiritual world are eternal. His earthly pastimes are similarly transcendental and eternal. As the Caitanya-bhāgavata states, "Even at this very moment Lord Gaurāṅga is enacting His eternal, transcendental pastimes, but only the most fortunate souls can see them." When the sun sets, it goes out of our sight, but it continues to shine somewhere on this globe. Similarly, when the Lord winds up His earthly pastimes, He continues to manifest them in one or more of the uncountable millions of planets in the universe. As Lord Brahmā declares in the Brahma-saṁhitā (5.39):
- rāmādi-mūrtiṣu kalā-niyamena tiṣṭhan
- nānāvatāram akarod bhuvaneṣu kintu
- kṛṣṇaḥ svayaṁ samabhavat paramaḥ pumān yo
- govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
I worship Govinda, the primeval Lord, who manifested Himself personally as Kṛṣṇa and the different avatāras in the world in the forms of Rāma, Nṛsiṁha, Vāmana, etc., as His subjective portions.
The cycle of four yugas, or millenniums—namely, Satya, Tretā, Dvāpara, and Kali—goes around a thousand times in one day of Lord Brahmā. The Bhagavad-gītā (8.17) confirms this: sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ. "By human calculation, a thousand ages taken together form the duration of Brahmā's one day." According to the Vedic calculation, one day of Brahmā sees the coming and going of fourteen Manus. Therefore, each Manu lives for seventy-one cycles of the four millenniums. At present we are in the period of Vaivasvata Manu, in the twenty-eighth cycle of the four millenniums, and it is the Kali-yuga. This Kali-yuga is very special, however, because Lord Caitanya appears in this age in His original form and propagates the esoteric science of pure love of Godhead. All this we learn from the scriptures. We have great expectations that this science of pure love of Godhead will be propagated world-wide in the immediate future.
During the Satya-yuga the mode of goodness is in abundance. Or one can say that when the quality of goodness increases in a person to the extent that he becomes situated in his original constitutional identity as a servant of the Lord, thus making his human life a complete success, at that time he enjoys the bliss and tranquillity of the Satya-yuga. The three modes—goodness, passion, and ignorance—are always present in this material nature. According to the predominance of a particular mode, the yugas change from Satya to Tretā to Dvāpara to Kali. The jīvas in Kali-yuga are predominantly in the mode of ignorance, and with with the increase of this mode the threefold material miseries expand unlimitedly. Thus people today are afflicted by a short life-span, ill luck, warped intelligence, lethargy, disease, and many other sufferings.