I have read in books that there are four yugas; Kali, Dwapara, Treta & Satya. Also, that Kali yuga started just after Krishna left his body which lasted for 6000 years ascending and 6000 years descending before Dwapara ascending since 1900.
1. How long will Dwapara & Treta ascend and descend before ascending to Satya?
2. Is Satya yuga the last yuga ascending forever or descends again to Kali?
3. If Kali yuga started after Krishna left his body, what was the yuga he was born?
—Bahniman Kakati, India
Not all traditions use the same dating for the yugas. I prefer the dating of Sri Yukteswar as outlined in his book, The Holy Science. Sri Yukteswar uses the duration of the yugas found in the Vedas and the Book of Manu. Satya Yuga is 4000 years long with 400 year transitions at the beginning and the end for a total of 4800 years (4000+400+400=4800). Treta Yuga is 3000 years long with 300 year transitions at the beginning and end for a total of 3600 years (3000+300+300=3600). Dwapara Yuga is 2000 years long with 200 year transitions at the beginning and end for a total of 2400 years (2000+200+200=2400). Kali Yuga is 1000 years with 100 year transitions at the beginning and end for a total of 1200 years (1000+100+100=1200). By adding together the length of all the yugas — 4800+3600+2400+1200 — we see that the ascending and descending half of the yuga cycle each last 12,000 years, for a total cycle of 24,000 years.
Sri Yukteswar calculated that the last Dwapara Yuga ended in 700BC, shortly after the passing of Krishna. According to his calculations we passed through both descending and ascending Kali Yugas from 700BC to 1700AD, and into ascending Dwapara Yuga transition in 1700AD and into Dwapara proper in 1900AD. Our current Dwapara Yuga will end in 4100AD, followed by ascending Treta Yuga until 7700AD, followed by ascending Satya Yuga until 11,500AD.
Sri Yukteswar said that our current Dwapara Yuga bestows on mankind the awareness of energy and the fine structures of matter — thus we call it the energy age. In the energy age we have learned that all matter is energy in a condensed form. We have also begun to become more aware of subtle energy — life force, prana, chi — that is the gateway to deeper spiritual awareness. Many practices, such as meditation, yoga postures, and acupuncture, whose effectiveness arises from becoming aware of and using subtle energy, come down to us from the previous descending Dwapara energy age that began in 3100BC and ended in 700BC.
If you would like to know more about the yugas, I have a website devoted to the subject: http://www.theyugas.com.
Puru (Joseph) Selbie