Monday, January 4, 2010

String Theory -A Beginner's View

I was watching a video clip of one of my favorite TV series 'The Big Bang Theory' a couple of days back(If you haven't watched it then you are really missing on a big thing in your life and i recommend that you leave everything else and watch it right now.)
Anyways ,back to the topic ,while watching the clip, 'Sheldon' mentioned the string theory and I searched for it on the net to see what exactly it is.
Then on opening today ,I came to know that today it is the birthday of Sir Isaac Newton and i felt inspired to write about some physics stuff.
Anything mentioned here about the string theory is what i understood of it and I think if you are a beginner at it like me ,it is quite interesting .

What is the need of the string theory? 
Presently the universe is explained on the basis of two basic theories :

  • The Quantum Theory-the theory of all the small things ,of all the sub atomic particles and how they act in their subatomic world.
  • The Theory of Relativity:This theory basically given by Einstein as an extension of Newton's mechanical models and theories explains how all the 'visible' things in the universe happen.It explains the big bang,black holes and covers space and time.
The problem is that both these theories are mutually exclusive.They just can't go together hand in hand.When we talk about the quantum theory we forget the theory of relativity .We assume that gravitation doesn't apply to the subatomic particles and things like that.Similarly, while talking about relativity we tend to forget all about the quantum theories.
All this doesn't sound acceptable in the perfectly symmetrical and simple universe.Here in comes the string theory which tries to explain everything there is to explain in this universe with a simple equation,on the basis of strings which vibrate in 10 dimensions and are the cause of all forces,all energy that there is .
If string theory is a valid one,it will cause a paradigm shift like the one which happened when Copernicus proposed that the Earth goes around in orbit around the Sun.This time the shift will be from the 3+1 dimensions of space and time to the 10 dimensional hyper space +1 dimension of time in which strings can move.

What are these strings?
When one hears of strings,the first thing that comes to mind is what are these  things that are supposed to make up everything.
Lets consider a ball.Now its hard enough to imagine that if shatter it into microscopically miniscule pieces we'll see electrons revolving around the neutrons and protons which further are made up of the point particles called quarks.
String Theory says that the quarks aren't the ultimate fundamental particles.If we  see even further what we'll see are vibrating loops ,the strings,vibrating in a certain mode to form that particular form .
So if there are strings ,then there's no need to consider electrons,protons or any subatomic particles ,you just have the String.

Where and how did it start?
It all started with the Greek group that called themselves the Pythagoreans.They worked out the laws of harmony on a violin string and realised that the resonance of the vibrating strings of violin could be explained corresponding to integers.They were marvelled by the fact that music could be explained on the basis of vibration of strings.This gave birth to the idea of perhaps being able to explain the whole universe by a simple equation on the basis of vibrations of strings.This idea was only revoked a few years ago.

Biggest Drawback:
The biggest drawback or one should say the problem that physicists face is that the equations of the string theory predict a presence of a 10 dimensional hyperspace.That is undigestable for most.
The theory for explaining everything being based on 10 dimensional hyperspace seems more like science fiction than science.
To prove the String Theory completely,one will have to recreate the big bang ,the start of the creation,which is not possible.
The image shows the meaning of string theory for most people .lol  (Source)

But still if someone were to find the proof of the String Theory ,the solutions to its equations,then at that time it will be the end of all research.It will explain everything.Our universe would be a solution of the equation.
The catch here is the fact that when the mysteries of the theory are solved it might appear that it was all in vein.The String Theory has no parameters or anything to tweak and thus the theory of everything might actually be a theory of nothing.

How are the 10 dimensions theoretically explained?
This is where the physicists start talking about the parallel universes.It says that the strings constitute different membranes in a much larger space of 10 dimensions called Branes.If it has enough energy a brane could even constitute a whole universe.We are living on one such brane ,a 3-D membrane in the wider space.
Assume a loaf of bread as a 10 dimensional space and the different slices as the different branes constituting the different parallel universes following absolutely different time lines and different laws of physics maybe.

In short at this very moment there might be various different universes right in your living room, the universe of the dinosaurs millions of years ago for us,a universe of the aliens  completely invisible to us just away from our reach since we are 'out of tune' with them due to our vibrations not being resonant with their's.It's like being trapped in the 3-D membrane like the characters of a movie are trapped on the 2-D screen of the theatre.

The theory that explains this concept of the 10 dimensions in a single place is the M theory.

The G-String:
The closed loops of strings are the ones which have no loose ends ,like a rubber band,and are responsible for gravitational force.They are called the G-strings or the Gravitons.Since the gravitons do not have any loose ends to tie them down,they are free to escape into the other dimensions and this is the reason for the decrease in strength of the gravitational force.
This escape of the G-string is the phenomenon that the physicists are trying to use to give some experimental support to the String Theory.At the Fermi Lab a huge atom smasher has been setup for this purpose which tries to detect the presence of the closed loops ,the gravitons, by detecting the escape of the graviton when two atoms collide head on and shatter into strings.
In simpler words,they try to detect the presence of the graviton by detecting the absence of the graviton.
For the purpose of this experiment ,one even bigger ,even powerful 'hadron smasher' is being built at the moment in Geneva,Switzerland.A lot of hopes of the scientific community are placed on it.

People also try to prove the existence of God on the basis of String Theory as the one who is able to move between the parallel universes and thus can move from any place to any other place at any time and being immortal because of being able to move from one time line to other.As He is able to see all 10 dimensions,He is able to see everything that there is to see.

Brian Greene,a physicist,tries to explain the briefs of String Theory.

What the Wiki says about String Theory?
Another great source on the topic.


Political Satire said...

Damn bro, I subscribed to your feed the other day and you just dropped some knowledge on my ass.

I've always been fascinated with String Theory but I haven't even looked into it in years - thanks for opening that door again.

I'll also check out that Big Bang Theory show, I believe I've heard of it. I though it was just a sitcom, not like you described.

My Space said...

I am glad you liked it.

Hope you like big bang theory too.i have my geeky moments in my life(though i am not a complete geek :P),but if you are like that even a little bit,you'll love the show.

Anonymous said...

Nice post.
The 10 dimensions were not theorized initially--it was added to make the equations work. When that happens in physics it is usually ad hoc. That doesn't mean its wrong but adding more dimensions so the equations will balance is suspect.

a god who has to use dimensions to survive defies the very definition of "God". That would be called a person--not God. God doesnt exists IN the universe--the universe exists IN Him. The best analogy would be the physical space you create in your mind when you dream is IN you. Your thoughts have no actual location in that dream space.
When we stop limiting our ideas to spacial beings, we can begin to see how the entire universe is easily manipulated by its creator.

God is Eternal..not immortal. an eternal being can have no beginning by definition and can have no end because he is not IN Time. Time and every other thing is a creation subordinate to his thoughts.