Hindu Cosmology

We begin with a few insightful quotes to set the tone for further exposition.

Carl Sagan, a distinguished scientist, one of the greatest popularizers of Science, arguably the greatest popularizer of Astronomy, Pulitzer prize winner, Author-Director-Actor of the world's most watched TV program "Cosmos", has the following to say about Hindu Cosmology (one of the episodes of Cosmos is on Hindu Cosmology):

"The main reason that we oriented this episode of Cosmos towards India is because of that wonderful aspect of Hindu cosmology which first of all gives a time-scale for the Earth and the universe -- a time-scale which is consonant with that of modern scientific cosmology. We know that the Earth is about 4.6 billion years old, and the cosmos, or at least its present incarnation, is something like 10 or 20 billion years old. The Hindu tradition has a day and night of Brahma in this range, somewhere in the region of 8.4 billion years."

"As far as I know. It is the only ancient religious tradition on the Earth which talks about the right time-scale. We want to get across the concept of the right time-scale, and to show that it is not unnatural. In the West, people have the sense that what is natural is for the universe to be a few thousand years old, and that billions is indwelling, and no one can understand it. The Hindu concept is very clear. Here is a great world culture which has always talked about billions of years."

"Finally, the many billion year time-scale of Hindu cosmology is not the entire history of the universe, but just the day and night of Brahma, and there is the idea of an infinite cycle of births and deaths and an infinite number of universes, each with its own gods."

Alan Watts, a professor, graduate school dean at Harvard University (1960s)

"To the philosophers of India, however, Relativity is no new discovery, just as the concept of light years is no matter for astonishment to people used to thinking of time in millions of kalpas, ( A kalpa is about 4,320,000 years). The fact that the wise men of India have not been concerned with technological applications of this knowledge arises from the circumstance that technology is but one of innumerable ways of applying it."
It is, indeed, a remarkable circumstance that when Western civilization discovers Relativity it applies it to the manufacture of atom-bombs, whereas Oriental civilization applies it to the development of new states of consciousness."

Dick Teresi, Author

"...the big bang is merely the prelude to the big crunch and the universe is caught in an infinite cycle of expansion and contraction, then ancient Indian cosmology is clearly cutting edge compared to the one-directional vision of the big bang. The infinite number of Hindu universes is currently called the many world hypothesis, which is no less undocumentable nor unthinkable.

Inspiration (Quotes from Hindu texts)

Neither being (sat) nor non-being (asat) was as yet. What was concealed? And where? And in whose protection?…Who really knows? Who can declare it? Whence was it born, and whence came this creation? The devas were born later than this world's creation, so who knows from where it came into existence? None can know from where creation has arisen, and whether he has or has not produced it. He who surveys it in the highest heavens, he alone knows-or perhaps does not know. (Rig Veda 10. 129)

For many ages, only darkness prevailed (i.e., the state before creation cannot be understood); the infinite, endless Lord was absorbed in the primal void. He sat alone and unaffected in absolute darknes. As He pleased, He remains in that state (of utter darkness). He has no rival. He is infinite and endless. 2 He is hidden throughout the four Yugas - understand this well. He pervades each and every body and heart. The One and Only Lord prevails throughout the Yugas. How rare are those who contemplate the Guru (i.e., Guru's Word), and (by contemplating the Guru's Word) understand this. 3 (Sri Guru Granth Sahib 1026).

The Math

Brahma's Age (Life Time) = 100 Brahma yearsOne Brahma Year = 3.1536 * (10^12) Human (or Earth) Years

12 Brahma Hours = 14 Manu Life Times = 4,320 Million Human Years

14 Manu Life Times = 1000 Maha Yugas

1 Maha Yuga = Kali Yuga + Dwapara Yuga + Treta Yuga + Krita Yuga = 4,320,000 Human Years

Regnal Period of 1 Manu = 71 Maha Yugas = 308 Million Human Years = 1 Manvantara

Kali Yuga = 432,000 Human Years
Dwapara Yuga = 864,000 Human Years
Treta Yuga = 1,296,000 Human Years
Krita Yuga = 1,728,000 Human Years

Now, the Vedas say, there are 7 worlds: Bhuloka, Bhuvarloka, Suvarloka, Maharloka, Janaloka, Tapoloka and Satyaloka. At the end of 14 Manvantaras, i.e., one Brahma daytime, Brahma goes to sleep and the first three lokas are destroyed in an intermediate deluge called "avantara pralaya", the latter four lokas survive. ALL worlds perish when Brahma life time of 100 Brahma years (3153 Billion Human Years) ends. No one really knows how many such Brahmas are there and how many such creations, exist...., potentially it can be infinite as per Hindu thought!!!

A note on lokas, they are planes of existence which differ in manifestation, the first 3 of the 7 lokas are gross and the latter 4 are subtle. The word loka is roughly translated to "world" in English, but we should take it in the original meaning, because the English word world always implies a 'gross' world only.

Where Modern Cosmology meets Hindu Cosmology

The time for the next "avantara pralaya" as per the Hindu cosmology and the time for the Sun to have spent its useful lifetime before exploding into a Red Giant and thus dissolving Mercury, Venus, Earth and Mars are in agreement - approximately another 4.5 Billion Years.
One Brahma Day is 8.6 Billion Years which is equal to scientific opinion on Sun's "main sequence star" life of approximately 9-10 Billion years.

The time it takes the Sun to go round the Milky Way galaxy, travelling at the speed of 217Km/s (1 light year every 1400 years) is 225-250 Million Years according to Modern Astronomy. This (approximately) agrees with the 308 Million Years for 1 Manvantara. So the life time of 1 Manu is equal to 1 Pradakshina of the Sun around the center of the Milky Way.

The fact that the Sun gives rise to planet Earth, sustains it (through continuous supply of energy), and finally destroys it (when it explodes into a Red Giant) is also stated in Ancient Hindus Texts in a symbolic and subtle way: "Srishti Sthiti Laya Hetave Virinchi Narayana Sankaratmane", says the Aditya Hridayam. This is again agreeing with 1 Brahma Day and the Sun's life as a "main sequence star".

Where We Need More Insight

However, the similarity between modern astronomy and Hindu cosmology has to pause here, until more research will bring more agreement into light. For, as per the Big Bang theory, the age of the Universe is around 13.7 Billion Years (which is the age of the oldest known star, not really a conclusive/direct measure of the age of the universe), whereas as per Hindu cosmology, Brahma is in his 51st year, so he has so far completed 1500 Billion Human Years.

Relevance

All right, we have all this math that broadly agrees on the scale (orders of magnitude) with modern science. What does it all mean? It means different things to different people with different outlooks. For the Scientists what is interesting is to know is why such a civilization which had such advanced knowledge in the halcyon past did not put it to use ("use" in the modern sense). Yes, verily as we saw in Part I of this post that Hindus wanted to put this to use to scale-up their level of consciousness rather than merely dole out a material invention that can give comfort to the gross body on the Bhuloka.

Those of you who might have attentively listened to a Sankalpam during pujas should immediately recollect how this is being put to use. The running yuga, the Manvantara etc., are all mentioned to fix our location on planet Earth and direct the prayer (ritual) to the intended (invited) Deity! In Hindu dharma, so far as I understand, the importance of Cosmology is this, not to lose touch with the Divine beings on higher realms and properly offer havans. This helps man to rise above the limitations of the gross body and gross world and climb up the ladder of consciousness.

Now we seem to be mixing science and religion? Yes, indeed we are, in Hindu tradition, there is no differentiation, Science and Religion, both are approached in a scientific fashion. Both go hand in hand. Where we differ with modern science is in the application of the knowledge, whereas we strive to use our science to uplift our level of consciousness, modern science tries to apply that knowledge for material inventions and bodily comfort.

Quotes
Cosmic Dream

Carl Sagan: There is the deep and appealing notion that the universe is but the dream of the god who, after a Brahma years, dissolves himself into a dreamless sleep. The universe dissolves with him - until, after another Brahma century, he stirs, recomposes himself and begins again to dream the great cosmic dream.

Swami Vivekananda:Hridi pranayati viswam vyaja matram vibhutvam [This universe arises in the heart of the Glorious one by mere thought]

Symbolism and Tribute
Carl Sagan:"The most elegant and sublime of these is a representation of the creation of the universe at the beginning of each cosmic cycle, a motif known as the cosmic dance of Lord Shiva. The god, called in this manifestation Nataraja, the Dance King. In the upper right hand is a drum whose sound is the sound of creation. In the upper left hand is a tongue of flame, a reminder that the universe, now newly created, with billions of years from now will be utterly destroyed."

References:

1. Kanchi Mahaswamigal on Jyotisha
http://www.kamakoti.org/hindudharma/part10/chap8.htm
2. Cosmos - By Carl Sagan p. 213-214
3. Carl Sagan's interview with Indian diplomat Placido D'Souza
http://www.rediff.com/news/jan/29sagan.htm
4. Vajrapani's Happy New Year Post
http://vajrapani.sulekha.com/blog/post/2007/12/how-do-extraterrestrials-celebrate-their-new-year.htm