KalaChakra - Life cycle of Time

KalaChakra - Life cycle of Time
Time is the measurement which connects past,present and future. The intervals,duration and events occur based on the time. Simply we check the time using clocks. Clocks are present measures of time. Time is never ending phenomena and our entire life depends on time.

Cultural beliefs :
According to our ancients, time is not a linear phenomenon, it is a cyclic phenomena. The course of time passes through  intervals(creation,destruction and re-creation) in a cyclic order. Time is divided into 'Krutha,Treta, Dwapara and Kali yugas'.  These four yugas combined named as 'Mahayuga' and 71 'Mahayugas' called 'Manvantra'. Such 1000 Mahayugas is called Kalpa.

Below are the reference of rough time spans of respective Yugas
Krutha Yuga     - 17,28,000 Years.
Treta Yuga       - 12,96,000 Years.
Dwapara Yuga - 8,64,000 Years.
Kali yuga          - 4,32,000 Years.
Each 'Manvantra' is ruled by one of Manu gods. A day of Lord Brahma(creator) is equal to 1000 Maha yugas or 1 Kalpa. A day/night of Lord brahma is equivalent to two kalpas. Lord Brahma evolved from the navel of Lord Vishnu. When Lord Brahma sleeps at night, Lord Shiva destructs everything and when Lord Brahma wake up, he creates everything again.
Currently we are in Kali yuga which is 28th Maha Yuga in Vaivasvatha Manvantara of ShvetaVaraha Kalpa. Approximately Lord Brahma has completed his 50 years in his total age of 100 years. Life span of Manu is one manvantra and at present Manu’s age  is 28 Mahayugas completed out of 71 Mahayugas.

Scientific Reasons:

• 'Aryabhatta', a famous astronomer from the time of Gupta emperor (476 A.D) given a value of one sidereal rotation of earth is 23 hours 56 minutes 4 seconds 0.1 fraction which is accurate with modern value 23 hours 56 minutes 4 seconds 0.09 fraction.
• 'Manvantra' which is 30,84,48,000 years is a time span to complete one revolution of Sun around the center of Milky-way.
• 'Kalpa' which is 432,00,00,000 years is referred as the age of universe. Life span of universe is 4 to 8 billion years which is compared to 1day,1 night of Lord Brahma. Modern scientists estimated the age of universe (elapsed time since big bang) as 13 billion years.
• Earth rotates around the Sun and the Sun rotates around another star. As the entire solar system moves in an orbit which is closer to Center of Universe which is narrated as navel of Lord Vishnu where the creator Lord Brahma evolved from.
• Lord Manu symbolically represents  the evolution of life. At the end of each Manu life span, destruction or dissolution of entire life forms takes place which is compared to one night of Brahma(state of rest) where Lord Shiva destruction happens. The final incarnation of Lord Vishnu known as Kalki avatar represents end of world that means destruction.