String Theory for Dummies - String Theory - String Theory Explained

We will discuss here- What is string theory, what are strings in string theory and how small are these strings. We will also answer, Why string theory is so important and how it has proved promising in answering the deepest questions in fundamental physics.

What are Strings in String Theory

Before the introduction of string theory, it was considered that the fundamental particles of the nature are point like particles. But according to string theory it is not true. String theory says that these fundamental particles are extremely small one dimensional objects known as strings. So strings are the smallest thing in the whole universe as everything, even the subatomic particles are made up of these one dimensional objects called strings. Graviton is a quantum mechanical particle that carries gravitational force. In string theory one of the many vibrational states of the string corresponds to the graviton.

String Theory Explained Video

What is String Theory

String theory deals with how these strings propagate through space and how do they interact with each other. According to the string theory all fundamental particles are actually tiny vibrating loops of string. Various properties of particles like mass and charge are determined by the vibrations of the one dimensional string like entities. According to researchers, the size of the string is about 10^-33 cm.

Why String Theory is Important?

Scientists hope that string theory will help in answering deepest questions related to fundamental physics. String theory has been applied to unravel mysteries of early Universe cosmology, black holes, nuclear physics and condensed matter physics. Quantum gravity is one of the deepest problems in modern physics. All the fundamental forces except gravity are described within the framework of quantum mechanics. As Albert Einstein described gravity using the general theory of relativity but the general theory of relativity is formulated within the framework of classical physics. According to Einstein's general theory of relativity, gravity is the distortion of space-time caused by the presence of matter. So a quantum theory of gravity was needed in order to reconcile general relativity with the principle of quantum mechanics. String theory can help us here. Actually string theory potentially provides a unified description of gravity and particle physics. It is a self contained mathematical model that describes all fundamental forces and forms of matter. So we can say that string theory is a candidate for a theory of everything. Now let’s get an idea about how small are the strings in string theory.

Size of Strings in String Theory

Actually a string is of the order of 10^-33. This number is so small that just by staring at this number you won’t get the idea. So let me make it simple for you with an analogy. Let’s assume an atom were magnified, to the size of the whole observable Universe, then a String would be the size of a tree!!! Now let me do one more comparison to make it more clear. This time I'll compare the size of an electron with the size of a string. So, if we increase the size of an electron equal to the size of the Earth, then a string would not be bigger than just a 3 storey building.