Introduction
to String Theory and Multi-dimensions
The universe as we know is very
bizarre, no matter how hard we try to understand it still we miss out something
or the other which is far more mysterious than the previous. From my previous
blogs we tried to understand the universe in large scale i.e. stars, black
holes, dark matter and dark energy, etc. In this blog we will try to understand it in smallest scale possible, going to the very depth of the it. Join me in this voyage to explore the unheard topic of the universe.
The modern physics stands on the 2
main theories which we call pillars of the modern physics. Einstein’s general
and special relativity which helps us in understanding the universe in large
scale ( ex; planets, stars, galaxies), about which we studied in my previous
blog and the other one is quantum mechanics which helps us in understanding the
universe in small scale (ex; atoms, electrons, neutrons). Over the years many
physicists tried to unify these both into one, trying to find a single equation
which gives us the entire understanding of the universe which we like to call
“The Theory of everything”. But when we combine both the theories, physics
begins to shake, rattle and in the end what we get is a nonsense equation. The
immediate question which strikes us is why can’t we combine both?
When we study the universe, we either
study on the large scale I.e. relativity or on the small scale of the universe
i.e. quantum mechanics but we never study both at the same time. This becomes
the reason for the above conflict in the physics. But the string theory solves
this conflict, it unifies these both theories. So, what is string theory?
To understand string theory, we need
to go back to basics, i.e. universe at the small scale. Ancient Greeks believed
that universe was made up of small undividable particles called atoms. Over
2000 years everyone believed that its true, then J.J. Thompson, Rutherford,
Neils Bohr, James Chadwick gave us the atomic model which gave us the constituents
of the atom i.e. Protons, electrons and neutrons.
Everybody believed that this cannot be
reduced further, these three were the fundamental particles. But in 1968
scientists at the Stanford linear accelerator center, making use of increased
capacity of technology to study the microscopic depth of matter found out that
protons and neutrons were made up of three smaller particles known as quarks.
Proton consists of 2 up quarks and 1 down quark whereas neutron consists of 2
down quarks and 1 up quark. Before that in 1950 2 scientists Frederick Reines
and Clyde Cown discovered fourth fundamental particle known as neutrino which
is known as ghost particles. These are massless particles which have no charge;
therefore, these are called as ghost particles.
Back in 1930’s physicists found
another particle called muon identical to electron but is 200 times heavier
than the electron. This shook the entire physics community, what we thought as
fundamental particles were not the one.
Using more powerful technology physicists
continued to study matter in depths by recreating the situations of big bang
and reducing these particles further, to our surprise we found 4 more quarks
called; charm, strange, bottom and top. Another heavier cousin of the electron
called tau.
Later two other particles like
neutrino were found (called muon-neutrino and tau-neutrino). These particles
are produced through high energy collisions. But the story doesn’t end here,
each of these particles has an antiparticle partner ( a partner with identical
mass but opposite charge) for example: electron has an antiparticle called
positron whose mass is same as electron but charge is +1. I bet you all are
going crazy by reading this, so were the physicists after discovering all these
particles. So, they found a pattern among all these particles and divided them
into 3 groups which are called families. Each family consists of two of the
quarks, an electron or its cousin and one of the neutrino species.
So how does this help us to understand
what string theory is? The particles we
see in the above table is the ultimate level to which an atom can be reduced.
If atom is a sentence, then these are the letters which further cannot be
reduced or broke down.
But, string theory suggests that if we
could examine these particles or reduce further with even more precession-
precession which is beyond our current technological capacity, we will find
that these particles are not point like but tiny 1- dimensional loop, like
infinitely thin rubber band. Each particle consists of vibrating, oscillating
filament which physicists called strings. Exciting isn’t it?
String theory says that whatever
properties we observe in a particle is a reflection of how a string vibrates in
various ways. Just as string in a violin and guitar have a resonant frequency at
which they vibrate, the strings of the particles too vibrate at a frequency
which determines the property of that particle.
Which in turn suggests that whatever
we observe, every atom, every element is basically made up of fundamental
vibrating strings which decide their properties, if somehow, we find the
strings frequency and change it, the property of each and every particle
changes. In fact, the fate of the whole universe changes. Because of this,
string theory stands at top for the theory of everything. As it deals with both
relativity and quantum mechanics.
If the string theory is right, the
microscopic fabric of our universe is a richly intertwined multidimensional labyrinth
within which the strings of the universe twist and vibrate rhythmically beating
the laws of cosmos. But the mathematics of the string theory is so complicated
that no one even knows the exact equations of the theory. instead physicists
use approximations and even approximate equations are so complicated that they
have been partially solved.
String theory completely changes our
understanding of the universe, it suggests that our universe has 11 dimensions.
Einstein’s relativity tells us that there are 4 dimensions that is 3 space
dimensions and 1 time dimensions, then what are other 7 dimensions? How string
theory changes our perspective of space and time? What other implications does
string theory have?
To all these questions we will find
the answers in the next blog, until then wonder about this amazing theory and
our strange universe…
