Ancient Vedic texts outline the timeline of our Earth. There are 4 major stages in the evolution of our planet, called the Yuga Cycles. The cycle repeats through 4 yugas: Krita Yuga, Treta Yuga, Dvapara Yuga and Kali Yuga.
In English, these are known as the Golden Age, the Silver Age, the Bronze Age and the Iron Age (the Dark Age).
As a Yuga Cycle moves through the four yugas, each yuga's length, along with humanity's moral and physical state, decreases by one-fourth.
The Golden Age (Krita Yuga)
The Golden Age is when virtues are at their highest and vices don't exist. Everyone is in Divine Alignment and recognizes God within them and God as them. There is no separation between the universe and the individual. In fact, there is no such thing as an individual, because it is understood that everything and everyone is connected.
The Golden Age is also the longest of the yugas.
The Silver Age (Treta Yuga)
In the Silver Age, virtues begin to break down and vices are introduced.
The Silver Age lasts 3/4 as long as the Golden Age.
The Bronze Age (Dvapara Yuga)
The Bronze Age brings further destruction of virtues, and vices are used by almost everyone.
The Bronze Age lasts 1/2 as long as the Golden Age.
The Dark Age (Kali Yuga)
And then we reach the Dark Age, Kali Yuga, where we are today. Virtue has all but disappeared. People indulge in vices daily, vices take over people's lives, and everyone feels separate.
What's interesting about Kali Yuga is that everything is backwards. Police are criminals, judges are crooks, priests are perverts and bankers are thieves. Sound familiar? Education disables the youth, and spirituality is based on fear, separation and not being like the "others." Addiction runs rampant. There's a strong attachment to material things and unhealthy attachments to other people. There is a lot of suffering.
Kali Yuga lasts 432,000 years, 1/4 the length of the Golden Age, and is believed to have begun in 3102 BCE. Near the end of Kali Yuga, when virtue is at its lowest, a cataclysm and a re-establishment of dharma occur, ushering in the next cycle's Golden Age.
A Different View: Sri Yukteswar's 24,000-Year Cycle
Not everyone agrees that we are stuck in Kali Yuga for hundreds of thousands of years. In his 1894 book The Holy Science, Sri Yukteswar, the guru of Paramahansa Yogananda (author of Autobiography of a Yogi), proposed a much shorter cycle of 24,000 years.
In his view, the cycle has two halves: a 12,000-year descending arc, when humanity's consciousness declines, and a 12,000-year ascending arc, when it rises again. Instead of lasting 432,000 years, Kali Yuga lasts 1,200 years in each half. Sri Yukteswar believed the much larger numbers came from a calculation error made by later scholars.
According to his timeline, the lowest point of the Dark Age was around 500 CE, and humanity left Kali Yuga around 1700 CE. We are now in the early stages of the ascending Dvapara Yuga, the Bronze Age. He linked this age to humanity's growing understanding of energy and subtle forces, such as electricity, magnetism and the idea that matter is energy.
If he's right, the darkness we see around us isn't the bottom. It's the old age falling away as consciousness slowly rises. Either way, both views share the same message: the cycle always turns back toward the light.
