The Silver Age is the second in a cycle of four ages. It lasts 1,296,000 years. In this age, people live for 10,000 years. They can achieve spiritual perfection by making great sacrifices.
The Copper Age is the third in a cycle of four ages. It lasts 864,000 years. During this age, people live for 1,000 years and approach spiritual realization by worshipping the Lord.
The Iron Age, also called the Black Age, the Dark Age, is the age of discord, hypocrisy, quarrels, indifference, decadence, and sin. It is the last in a cycle of four. It lasts 432,000 years.
This is the current age, the one we are in, and 5,000 years of which have already passed. It is essentially characterized by the gradual disappearance of the principles of religion, and humankind's sole concern is to obtain material comfort. Unlike the Golden Age, the Silver Age, and the Copper Age, the Iron Age is not at all conducive to spiritual fulfillment. The lifespan is 100 years.
In the Iron Age, the last and the one in which degradation is widespread, human defects are numerous, and to obtain the same benefits as the previous ages, humankind can glorify God by chanting His holy names, “Hare Krishna.”
The four ages—the Golden Age, the Silver Age, the Copper Age, and the Iron Age—follow one another in chronological order. However, they sometimes overlap. During the reign of Vaivasvata Manu (the Sanskrit word Manu means “the father of humanity”), for example, in the twenty-eighth cycle of four ages, the third preceded the second. In this age, Lord Krishna also chose to appear, and for this reason, the normal course of time underwent certain alterations.
In the Golden Age, all human beings—women, men, and children—were all under the sign of virtue, but since the advent of the Silver Age and the Copper Age, we have witnessed the gradual decline of virtue and the degradation of the human mass. In the present age, the one we live in, the Iron Age, virtue is practically nonexistent.
Indeed, systematic listening to or attentive reading of the sublime pastimes, attributes, qualities, excellences, and holy names of Krishna, the Supreme Personality of Godhead, leads to eternal life.
All those who desire to attain the total perfection of existence must listen with a submissive ear, or read with great attention, everything related to the spiritual and absolute pastimes, attributes, qualities, and excellences of the Supreme Personality of Godhead.
Systematic listening or reading implies an ever-deepening knowledge of the person of Godhead as He really is, which in turn leads to an evolution towards eternal life.