Wednesday, July 17, 2013

# Universe


Lie down under the sky on a clear,dark night and look up.What do you see?Bright,beautiful,mesmerizing stars stretched like a canopy overhead.At such times it is not unusual to wonder,what is this universe?Where does it begin & where does it end?How large is it?What exists there-on those stars?What are they made of?Is there air,water,hard ground,vegetation & life over there?

Ah!So many questions but scant answers.Still, we are better placed than our ancestors today,to get an inkling into these mysteries.This universe of which we are an infinitesimal part,is"the totality of existence" including stars,planets,intergalactic space & all matter and energy.An important distinction needs to be made here-the above description refers to the observable universe -the farthest distance it is possible for us to see from earth.The diameter of this universe is 93 billion light years.Naturally no one knows what exists beyond that.

It is widely accepted that the universe originated with a big bang,before which all matter was concentrated at one single spot.After the big bang, matter began to scatter in all directions,leading to the formation of galaxies consisting of dust,gas & countless stars.A number of atoms fused together to make stars & these stars were drawn together into various galaxies.The stars orbit the center of a galaxy's mass.The galaxies are moving outwards at an accelerating pace.There are vast intergalactic spaces between these galaxies and these spaces are expanding continually.

Although the big bang theory explains many things,what caused this bang & from where all the matter came-nobody knows.Nature,or God,does not reveal all secrets!According to Wikipedia Hindu cosmology comes nearest to modern scientific views about the origin of universe.Rig Veda maintains that the universe emanated from 'hirnyagarbha' or the golden womb of Brahman--the supreme consciousness.Hinduism encompasses various viewpoints in it's repository but it is widely believed that a long chain of creation & destruction of universe goes on.The Hindu view of various universes also tallies with the modern concept of multiverse. But at one place in Rig Veda(10.129.1-7)there is also this interesting agnostic statement:--
Who really knows,and who can swear
How creation came,when and where!
Even gods came after creation's day,
Who really knows,who can say
When and how did creation start?
Did He do it?Or did He not?
Only He,up there,knows maybe;
Or perhaps,not even He.

Looks like we come back to square one on that question!

But we have a lot of information about the composition of the universe today.It is a well known fact that there are innumerable galaxies in the universe.But how many?
It is difficult to arrive at an exact number but the current estimate rests at 100-200 billion galaxies.Most of them are probably small,dwarf galaxies while some are huge,spiral ones like the Milky Way,which has 400 billion stars.Dwarf galaxies probably contain as few as ten million stars but in large spiral galaxies, the number could go up to hundreds of billions or even a trillion.It is unlikely that the picture above is of Milky Way because we,being inside the galaxy,cannot click it from above.It might be another spiral galaxy or an artist's interpretation.

We see lots of stars on a clear night and many,many more can be seen through powerful telescopes.Do not miss some spectacular images taken by hubble at this site.The observable matter in sky is spread evenly all round--all areas of the universe look similar.But these visible bodies form only 4% of the universe.Apart from them,there is 73% dark energy &23% cold dark matter.Stated in simple terms,vast open spaces far out-weigh the heavenly bodies.

Outer space is an enigma.Einstein was the first person to realize that this space is not completely empty.It contains few atoms of hydrogen & electromagnetic radiation.'It is the closest approximation to a perfect vacuum.'There is no friction & all celestial objects slither easily along their established orbits.The temperature in space is absolute zero-which means the coldest possible temperature.

Here are some amazing facts about the universe:--

*Earth spins at an equatorial speed of 1,670 km/h.

*It revolves round sun at a dizzy speed of 100,000 km/h.

*Sun,along with it's solar system, takes 200--225 million years to complete one orbit around the Milky Way.

*Milky way rotates at an astonishing speed of 270 km per sec.

*It is racing through space with reference to cosmic background radiation at this astounding speed of 2.1 million km/h.

*Now think--are you really sitting at the same place while you are resting in your armchair???Add up all these astronomical speeds & then decide how far you must have travelled in one second!It is truly mind boggling!

*The sun is not considered to be a huge star,yet it can accommodate one million earths!

*Alpha Centauri-the star nearest to sun,(and in the Milky Way only) is 4-3 light years way from earth!

*Like many other galaxies,Milky Way too,has a black hole at it's center.It is a super massive black hole called Sagittarius A which is 26,000 light years away from earth

*Milky Way & Andromeda galaxy are set on a collision course.

*According to astronomers about 275 million new stars are born every day.

*One more shocker--light travels at approximately 186,000 miles per second;if we could travel at that speed we would take 100,000 years to cross the Milky Way alone!Our puny minds can never visualize the enormity of this universe;much less understand the power and brilliance of it's creator!!!!!

Resources
http://en.wikipedia.org/wiki/Universe
www.outerspaceuniverse.org/what-is-the-temperature-of-outer-space.html
http://www.astrosociety.org/edu/publications/tnl/71/howfast.html
Image courtesy google.

27 comments :

  1. The way you provide the Universe Facts are amazing and love reading it...

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    1. Thank you Vijay,your appreciation means a lot.

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  2. Awesome write with tons of info. Very interesting read.

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    1. I am very happy you liked it-thanks a lot.

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  3. very very very nice post. We come back to square one. I had numerous debates with my friends in virtual and real life on this issue. Science and religion are too huge topics to talk about and the interference of one in the other is inevitable. But since i am science person, i edge away from religion. mystery mystery galore!!!!

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    1. Ran in jan that was a very potent observation-somewhere down the line science has to come near metaphysics.So much of order & organisation cannot be a fluke.

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  4. Very informative post! Thanks!

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  5. It's a very informative post with knowledge tucked in.But,in my opinion it is too long for a blog post

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    1. Chowla jee the topic is such-i could not restrict myself.I wanted to share all the interesting facts which wowed me.

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  6. The universe has always fascinated me with its mystery and vast expanse. There is so much we will never know.

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    1. Yes it is a fascinating subject alright.The more we learn,the more we realize how little it is.

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  7. Fascinating to say the least!!

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  8. Interesting and informative Indu! What next? :)

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    1. Now i will have to go outside the universe,i suppose!
      Tell me if you have any suggestions.

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  9. There is a scene in Ice Age movie where a mammoth who kept saying all this while that he was the largest thing on earth finds himself amidst gigantic dinosaurs and utters in bewilderment 'I feel so puny' I felt this after reading your post :) The Rig Veda quote was awesome

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    1. It is a marvel how puny we are and yet see how far science has taken us.
      True Jaishree ,one does not know what to make of it.

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  10. this post triggers one of my childhood memories.when i was kid,i used to visit my grandma village,while travelling in bus i used to take window seat to look into deep and thick forest with lots of gorges.i used to think that deep inside forest saints, rishis and gods could be meditating like most of villagers notion.after growing up i can see only dense trees and all those stories of saints,gods meditating deep inside forest was result of limited consciousness or immaturity of mind.

    same is with the universe,when we look at it,it may look big,large and mysterious like dense forest.when we close eyes, a grown up mind consciousness is larger than universe to clear all the existing misbeliefs. it must be just bunch of stars spread over certain area like trees and gorges in forest.

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  11. this post triggers one of my childhood memories.when i was kid,i used to visit my grandma village,while travelling in bus i used to take window seat to look into deep and thick forest with lots of gorges.i used to think that deep inside forest saints, rishis and gods could be meditating like most of villagers notion.after growing up i can see only dense trees and all those stories of saints,gods meditating deep inside forest was result of limited consciousness or immaturity of mind.

    same is with the universe,when we look at it,it may look big,large and mysterious like dense forest.when we close eyes, a grown up mind consciousness is larger than universe to clear all the existing misbeliefs. it must be just bunch of stars spread over certain area like trees and gorges in forest.

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  12. First of all i am happy to have triggered your childhood memories because they are always-or should i say mostly-very refreshing.
    Regarding universe,well each one of us has a different POV.

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  13. Ever since cosmologists started to trace events backward in time based on the Big Bang theory, their views, which focused only on the very large, got smaller and smaller....Astronomy is an interesting subject. I liked the stars and moon, but, never liked maths,else would have studied astronomy- the science of studying the heavens!!!
    Wow!! Watched the fascinating video twice! Thanks for the tour, Indu..Love this!

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  14. You know Panchali,when i joined college i did not know much about the various streams which could be pursued,nor were my own inclinations so very pronounced;but the internet now supplants formal education.
    And i am glad you liked this post.

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  15. Amazing facts. This is so fascinating and never ceases to amaze us!

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Thanks for reading my post.I hope you liked it :).