String Theory For Dummies

Do you know about the ‘Theory of Everything’?

The theory of everything is about, well everything. It is known as the merger of two of the most important theories in physics: quantum physics and the theory of relativity.

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How does it involve strings?

In the 1970s the physicist discovered a one-dimensional object that they called string. These vibrating filaments of energy were then talked about in relation to the elemental particles and the way they interacted with each other. Hence, the name string theory.

The strings were of two types:

  • Open string: a string that whose ends do not meet
  • Closed string: a string whose ends meet to form a loop

However, the strings could modify themselves through interactions. Through five fundamental interactions, the open strings could join together to form a closed string. Later these closed strings could split apart and become open strings again.

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Why is this important?

The closed strings have the ability to explain the gravitational force. The fact that open strings could be changed into closed strings meant that all the strings could be used to describe gravitational force.

Therefore, the string theory did not only focus on the particles of matter but also the gravitational force being applied to them.

Now, that we are clear about the background of the string theory.

Let’s shed some light on the other content that makes it great:

Quantum Gravity

The laws of physicist have two major theories:

  • Quantum physics: It deals with the basic particles of nature
  • Theory of relativity: It deals with the larger forces of nature like planets and galaxies that attracted each other to create a gravitational pull

Both the theories are crucial to physics. Yet, they have radically different ideologies and always present contradictory ideas. The attempt to unify them is called quantum gravity and the string theory is its greatest advocate.

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The Union

The union of quantum physics and relativity can only occur if theorists can explain how the four distinctive phenomena of nature: the gravitational force, nuclear force, weak nuclear force and electromagnetic force come together.

Relativity primarily focused on gravity, while quantum physics revolved around the other three forces.

The theorists believe that in earlier times high energies of the universe made this possible. This means that instead of four forces of nature we had just one, that too in the form of a string.


Another clincher in the theory is the connection that exists between two diverse particles of universe, the bosons, and fermions. This super close relation is called Supersymmetry and it states that every boson has a fermion made for it. (Think: soul mates!)

However, this symmetry is still just a theory and hasn’t been proved yet.

The Other Dimension

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Our world is made up of three dimensions. However, the string theory needs an extra dimension to operate.

Where are these extra dimensions? They are either too compact like the little strings of energy which makes them invisible or are an extension of the strings attached to a brane (sheet) that is inaccessible to us.

Once the theorists have cracked the code to prove string theory, they will be able to unlock the mysteries of the universe.

In short: the world is made up of strings!