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Śri Īśopaniṣad
literature. The Vedic literature is full of knowledge matured by experience. But modern man is averse to receive knowledge from the  Vedas ,  Purāṇas , and other scriptures.
In the  Viṣṇu Purāṇa  we have information that Lord Viṣṇu, the Personality of Godhead, possesses different energies, known as  parā , superior, and  aparā , or  avidyā —inferior. The material energy in which we are at present involved is called the  avidyā , inferior, energy; and the material creation is made possible by such energy. But there is another, superior energy called the  parā-śakti , where everything is different from this material inferior Nature. That nature is the eternal or deathless creation of the Lord.
All the material planets—upper, lower and intermediate, including the Sun, Moon and Venus—are scattered over the universe. These planets exist only during the lifetime of Brahmā. Some lower planets, however, are vanquished after the end of one day of Brahmā, and they are again recreated during the next daytime of Brahmā. Time calculation on the upper planets is different from that of ours. One of our years is equal to twenty-four hours, or one day and night, on many of the upper planets. The four ages of Earth ( Satya ,  Tretā ,  Dvāpara ,  Kali ) make a duration of twenty-two thousand years and five months in terms of the time of these upper planets. Such a length of time multiplied by one thousand is one day of Brahmā, and one night of Brahmā is the same. With such days and nights accumulating into months and years, Brahmā's life is estimated at one hundred years. And at the end of his life, the complete universal manifestation becomes vanquished.
The living beings residing in the Sun and Moon, as well as those in the  Martya-loka  system—which includes this Earth and many planets below the Earth—are all merged into devastating water during the nighttime of Brahmā. During this time no living beings or species of life remain manifested, although spiritually they continue to exist. This non-manifested stage is called  avyakta . And again, when the entire universe is vanquished