String Theory : The Theory of Everything
Before we get into the basic founding principles of this often misinterpreted theory , i would like to acknowledge that this theory is still not proven and many theoretical physicists , in the modern era , are still trying to work out the science behind it .
As we all know , Our entire universe around us is composed of constituent particles known as atoms . Further these “atoms” were made to collide with each other to give rise to a new set of particles such as protons , electrons etc. known as the elementary particles . The basic idea of string theory , now is that these elementary particles are composed of strings ( present in a single dimension) which is similar to the strings in guitar which vibrate to produce different notes , these strings , however , vibrate in different dimensions or frequencies to produce different elementary particles , each different from one another in terms of their physical properties .
To search further deep , let us go to the very beginning , 1907 , the time Einstein was working out his general theory of relativity (and to explain this force known as gravitational force ) , although Newton did provide some of the most important equations relating to the gravitational force he could not explain why that force existed in the first place , Einstein took on this task and explained it as follows : He considered that space in itself is a flat “sheet” as long as no matter is present in it , but as soon as a mass , lets take The Sun , is dropped on it , that sheet will inevitably bend , creating somewhat a curvature, that curvature is gravity itself which allows other masses such as the earth to move around it which itself bends the fabric of space-time , consider it as this , you have a very fine sheet of rubber now if you drop a plastic ball on it , it will naturally bend and if you now try to throw marbles around the centre it will orbit the centre that is the ball, somewhat attracting it .Thus gravity came to be known as “The curvature of space-time itself” .
Currently , our universe is composed of 4 fundamental physical forces -Gravitational force , Electromagnetic force , strong and weak force . All of these forces , at the quantum level are undertaken by the elementary particles such as The Electromagnetic force which is mediated by photons(particles of electromagnetic wave or well , light) and so on . All of these elementary particles constitute what we call the Standard model of physics : categorised into two categories : fermions and bosons . Till now, this model is the best mathematical function of our current universe but this model leaves one grand force out of it , that is the gravitational force . At the quantum level , gravity was said to be mediated by the quanta of space-time curvature , i.e graviton . When we incorporated the graviton into the standard model , the mathematics of it broke down , that result shook the world of physics .
But then entered their messiah , The string theory which promised to unify all the fundamental forces present in our universe into one master equation , one final depiction of this universe — the theory of everything . When scientists looked for a solution to this crisis present in the standard model , they started from the beginning , from only 1 dimension which is a string! the only thing more complex than the point like elementary particles . According to the string theory , strings then were considered as the most fundamental , indivisible particles . These strings as mentioned above are little threads of energy with different frequencies which instead of producing different musical notes , produced different particles , this principle accounted for the presence of different physical properties in different elementary particles . But the mathematics of string theory presented a problem , the mathematics of the string theory only worked in a universe of 10 dimensions of space and 1 dimension of time . Some physicists like Kaluza and Klein in 1900s had already discussed the topic of extra dimensions in the universe by arguing that some smaller dimensions might be curled up into each other making it invisible to the naked eye of human beings but an organism like an ant will see more than 3 dimensions of space that we see , for example a rod with some thickness might just look to us like a normal wire in 3 dimensions if looked from far away but for an ant which is crawling on the rod , it can move curving downwards or curving upwards experiencing more dimensions than the current 3 that we can see .
The string theory uses the same principle in which the extra dimensions curl up in each other making it invisible to us on the normal physical scale . Now the strings vibrate in different patterns right , why is that so , because the vibration of the string depend upon the geometry in which the strings intertwine with each other , similarly when different notes are produced based on the position of air holes on the body of an instrument and all of this allowed the graviton to be present in this theory . Some scientists still think that presence of extra dimensions is not possible in our universe , but the mathematics still work in string theory . So , It does not matter if it is correct or wrong , it is still one of the biggest experiments carried out in the world of physics in the 21st century .
