Time Periods of Yugas

Question:
hi all
i had always wondered abt the time period of different yugs.
can someone tell me the the exact period of dwapar yug, treta yug, satyug and finally kalyug and can they anyway be connected to the dates or years that we understand?????


My Reply:
The purana concept of Yuga time scales is:

1. Satya Yuga or Krita Yuga - 1,728,000 years
2. Treta Yuga - 1,296,000 years
3. Dvapara Yuga - 864,000 years
4. Kali Yuga - 432,000 years

But there is many other views about the same. I find the concept of Yugas put by Swami Sri Yukteswar Giri (guru of Paramahansa Yogananda) more appealing.

Quoting from wiki:

In his book, The Holy Science, Sri Yukteswar explains that the descending phase of Satya Yuga lasts 4800 years, Treta Yuga 3600 years, Dwapara Yuga 2400 years, and Kali Yuga 1200 years. The ascending phase of Kali Yuga then begins, also lasting 1200 years; and so on. The ascending phase of Kali Yuga began in September of 499 CE. Since September 1699, we have been in the ascending phase of Dwapara Yuga, according to Sri Yukteswar. Evidence exists to support Sri Yukteswar's theory. For example, the average life span is getting longer (see above).

According to the traditional concept, the 4 yugas go in a cycle. ie:

Satya Yuga --> Treta Yuga --> Dwapara Yuga --> Kali Yuga --- end of a cycle --> Satya Yuga…..

But according to Sri Yukteswar Giri:

Satya Yuga --> Treta Yuga --> Dwapara Yuga --> Kali Yuga --- end of a cycle --> Kali Yuga --> Dwapara Yuga --> Treta Yuga --> Satya Yuga..

Also in his his case, the shift from one yuga to another is not sudden but continious. ie, the ending phases of Dwapara yuga and beginning phases of Kali yuga will overlap. Then there is ascending and descending of each yuga.

I am no scholar in this regard, but I find this more appealing, as somehow the concept of a wavy-cycle of time appeals more to me than the concept of abrupt shifts in a cycle of time. This concept of abrupt shifts from full Kali to Satya yuga is more like a some vague unknown reason (seen from the concept of impersonal, abruptness is always less appealing to the mind)


PS: The wiki article on Hindu Cosmology is a nice place to start with.

This article by Subhash Kak is also worth reading.


Question:
Surya, doesn't this negate the concept of pralaya?


My Reply:
According the puranic metrics of time:

One cycle of the above four yugas is one mahayuga (4.32 million solar years)

A manvantara consists of 71 mahayugas (306,720,000 solar years)

After each manvantara follows one Sandhi Kala of the same duration as a Krita Yuga (1,728,000 = 4x solar years). (It is said that during a Sandhi Kala, the entire earth is submerged in water.)

A kalpa consists of a period of 1,728,000 solar years called Adi Sandhi, followed by 14 manvantaras and Sandhi Kalas.
A day of Brahma equals
= (14 times 71 mahayugas) + (15 times 4x solar years)
= 994 mahayugas + (60 x solar years)
= 994 mahayugas + (6 times 10 x ) solar years
= 994 mahayugas + 6 mahayugas
= 1000 mahayugas

The concept of Pralaya comes after the end of day of Brahma.

In Hindu cosmology, a universe endures for about 4,320,000,000 years (one day of Brahma, the creator or kalpa) and is then destroyed by fire or water elements. At this point, Brahma rests for one night, just as long as the day. This process, named pralaya (Cataclysm), repeats for 100 Brahma years (311 trillion human years) that represents Brahma's lifespan.

So as it appears, the cycle of pralaya comes into picture only at the end of a day of Brahma (ie., one kalpa or 1000 Maha yugas) There is no reference of any pralaya occurring at the end of each maha yuga as well. So no pralaya is taking place in between the end of a maha yuga and the beginning of a new one until the end of 1 kalpa (1000 maha yugas.)

Hence in both the case, pralaya can be accounted.