Friday, July 20, 2007

We are living in a Blackhole!!!(or maybe ???)

I have been hooked on to the book "Cosmos" by Carl Sagan for quite some weeks now. Its one of those books which I never got to read during my school or college days, but heck, better late than never!

Anyway, so there is this theory (hypothesis or a conjecture or an idea, it doesnt matter what you may call it) which amazed me. And it says, we are in a blackhole! Stunned? let me explain in as many words as the book does (go ahead and buy the book, its worth it, really!).

Wikipedia defines blackholes as "an object with a gravitational field so powerful that a region of space becomes cut off from the rest of the universe – no matter or radiation, including visible light that has entered the region can ever escape." Now consider this, if you are peering through a telescope into distances billions of light years away, and say you live for that many years. It may be possible, that after many billions of years, you will be looking at the back of your head.How, well light reflected from the back of your head traverses the entire cosmos and you look at it through the telescope! Light does not escape the cosmos,nor can we, so are we not in a blackhole?
Now you may argue that light travels in a straight line in vacuum!Well, light travels in a straight line only in 3 dimensions as we percieve it. How do you know that in dimensions higher than 3, it doesnt bends, or distorts and reaches the same spot after the billions of years that it takes to traverse the cosmos?

An analogy, I will use the same that the book does. Suppose you and everything on earth is 2-D. You have a sense of forward-backward, right-left but no up and down.Now in this 2-D existence of yours you walk straight, and after walking for thousands of kilometres, instead of reaching an edge as you would wish in your 2-D picture of earth, you end up where you started from! Now coming back, you are definitely not stuck in 2-D, but we definitely are stuck in 3-D. So maybe if we had a sense of higher dimensions, we would see light bending! And maybe much more, like say if we were 2-D creatures, we wouldnt have seen birds, and likewise, maybe we do not percieve many creatures who maybe visible in higher dimensions? We see only their projections in 3D and do not understand what they are or why do they even exist or what they are doing or why they are doing what they are doing...I think you get the idea (btw their projections may look like this in 2D).

Food for thought? Let me know! In the meanwhile, look around you if you were curious whats in a blackhole.