Four cosmic ages (yugas) ( 4.32 Billions Years )

 Four cosmic ages (yugas)

When explaining the various measurements of time, Vishnu Purana (1.3), Srimad Bhagavatam (3.11.18-39), Bhagavad-gita (8.17), Vayu Purana (chapter 57) and others, such as the Mahabharata (Shanti Parva, 231.12-20), all agree on the measurements of the durations of the yugas, as explained below.

One cycle of the four yugas together is 12,000 years of the devas called divine years. Each of these years is composed of 360 days, and each of their days is equal to one human year. So Krta-yuga is 4000 divine years in length, Treta-yuga is 3000 divine years in length, Dvapara-yuga is 2000 divine years in length, and Kali-yuga is 1000 divine years long, with the addition of the conjoining portions of the sandhya and sandhyamsa. Each yuga is preceded by a period called a sandhya, which is as many hundred years in length as there are thousands of years in that particular yuga. Each yuga is also followed by a period of time known as a sandhyamsa of the same length. In between these periods of time is the actual yuga.

Krta or Satya-yuga (Golden Age)

Duration - 4,800 demigods years (4000 + 400 sandhya + 400 sandhyamsa)

or 1,728,000 human years

Life span - 100,000 years (Brahma vaivarta Purana 4.90.12, SB 4.12.13: Dhruva Maharaja ruled for 36,000 years)

Yuga-dharma (SB 12.3.52 lists all yuga dharmas) - meditation or astanga yoga

Yuga-avatara - white with four arms, has matted hair and wears a garment of tree bark. He carries a black deerskin, a sacred thread, prayer beads and the rod and waterpot of a brahmacari. (SB 11.5.21)

Symptoms of Satya-yuga: The people are peaceful, non-envious, friendly and naturally Krsna conscious. In Satya-yuga there was no division of asrama, everyone was a paramahamsa. There was no demigod worship, only the worship of Krsna and religion was perfectly practiced. (SB 9.14, 11.5.21-22)

Treta-yuga (Silver Age)

Duration - 3,600 demigod years (3000 + 300 sandhya + 300 sandhyamsa)

or 1,296,000 human years

Life span - 10,000 years (SB 5.17.12)

Yuga-dharma - Fire sacrifice (yajna)

Yuga-avatara - red with four arms and golden hair. He wears a triple belt representing initiation into the three Vedas. His symbols are the sruk, sruva, etc. (ladle, spoon and other implements of sacrifice).

Symptoms of Treta-yuga: In Treta-yuga the people are thoroughly religious. In Satya-yuga people are naturally Krsna conscious. In Treta-yuga they are inclined to become Krsna conscious. To achieve that end they are very strict in following Vedic principles.

Dvapara-yuga (Copper Age)

Duration - 2,400 demigod years (2000 + 200 sandhya + 200 sandhyamsa)

or 864,000 human years

Life span - 1,000 years

Yuga-dharma - Temple worship (arcana)

Yuga-avatara - his complexion is dark blue. He wears yellow garments. His body is marked with Srivatsa and other distinctive ornaments, and He manifests His personal weapons.

The original Personality of Godhead from whom all other incarnations expand is Sri Krsna. He appears once in a day of Brahma, during the period of the seventh Manu (Vaivasvata) in the 28th divya-yuga. The original Personality of Godhead Krsna only comes once in a day of Brahma. Although in every Dvapara-yuga there is a yuga-avatara, they are all expansions of Visnu, who is an expansion of Sri Krsna.

Symptoms of Dvapara-yuga: In Dvapara-yuga people have the weaknesses of mortal beings, but they have a strong desire to know about the Absolute Truth and they worship the Lord in the mood of honoring a great king, following the prescriptions of both Vedas and tantras.

Kali-yuga (Iron Age)

Duration - 1,200 demigod years (1000 + 100 sandhya + 100 sandhyamsa)

or 432,000 human years

Life span - 100 years

Yuga-dharma - Chanting the Hare Krsna mahamantra (harinama sankirtana)

Yuga-avatara - golden or yellow but generally black. Lord Caitanya, who is Krsna Himself, appears only in the Kali-yuga immediately following the appearance of Sri Krsna in Dvapara-yuga.

Symptoms of Kali-yuga: "O learned one in the age of Kali, men have but short lives. They are quarrelsome, lazy, misguided unlucky and above all, always disturbed." (SB 1.1.10)

The four yugas are known as a divya-yuga, or maha-yuga. One divya-yuga is 12,000 years of the demigods (4,320,000 human years). One thousand divya-yugas equals one day of Brahma (4,320,000,000 human years).

In each Brahma's day there are fourteen Manus (patriarchs of mankind). Each Manu enjoys a life of seventy-one divya-yugas or 852,000 years of the demigods (306,720,000 human years). After the dissolution of every Manu a new Manu comes. With the change of Manu the universal management also changes. Each manvantara is preceded and followed by the yuga-sandhya in length of one Satya-yuga. The yuga-sandhyas are periods of partial devastation and creation.

Brahma's life consists of 36,000 days and nights (of the same length), or 311,040,000,000,000 human years.

We live in Kali-yuga of the 28th divya-yuga of the 7th Manu of the 12th kalpa (called Sveta-Varaha) (SB 2.10.46p., Skanda P. 2.39-42), in the 51th year of Brahma. The beginning of this kalpa was 2.3 billion years ago (453 mahayugas back).