String Theory and Multiverse – 7 Things You Need to Understand.  Modern physics revolves around the theories of Quantum Mechanics and General Relativity. General Relativity focuses on gravity to understand and explain the universe in high mass and large scale regions, including clusters of galaxies, stars, and galaxies. Quantum Mechanics, on the other hand, is about the non-gravitation forces, such as subatomic particles, low mass, and small scale.

In the early 20th century, Nature’s fundamental constituents were said to be indivisible and dot-like particles. But everything changed when string theory was created and formulated by Andre Neveu and John Schwarz of Princeton University. It proposes that at the heart of each particle is a small string-like filament. 

Here’s the thing. Multiverse string theory remains one of the most confusing ideas in modern physics regardless of scientists’ intensive and thorough research in the US and other countries across the globe. But worry no more. Below, we have gathered some points you need to understand about string theory as a beginner. 

1. A Short Overview of The String Theory 

String theory has become a famous idea in physics since 1968. However, it was hard to find any related information on string theory online before. But now, it is different as there are multiple platforms to rely on and trust. So what is string theory, though? 

As the name implies, it is a theoretical framework that replaces point-like particles with one-dimensional objects. For example, a string looks like an ordinary particle, especially on a distance scale, but with properties such as charge and mass. Experts also believe that the theoretical framework has a vibrational state corresponding to a quantum mechanical particle, also known as the graviton. 

While it has an advanced contribution to nuclear physics, early universe cosmology, black hole physics, and other fields, it provides a reliable description of particle physics and gravity, making it a candidate for a self-contained mathematical model called the theory of everything. 

2. Strings and Branes: What Are They?

We already know that string is a one-dimensional filament. But it is also divided into two forms, namely open and closed strings. What’s the difference between the two? An empty string does not connect as it has an end equivalent to a line interval. A short series, on the contrary, creates a closed loop. It does not have any endpoints and is usually compared to a circle. Scientists say that not every string theory has an open string, but it must contain a closed series. How about a brane? It is a sheet-like object that a line can attach to. It can also move thru spacetime based on quantum mechanics because they have attributes like mass and charge. 

3. Superstring Theory

You probably have encountered supersymmetry a couple of times already. What is it, you may ask? Supersymmetry, commonly known as a superstring theory, describes the relationship between particles like fermions (matter particles) and bosons (force particles). Experts say that fermion has a counterpart of boson or vice versa. Unfortunately, supersymmetry remains theoretical because professionals have never seen bosons and fermions yet. 

Physicists believe that generating two particles require a significant level of energy. They also think that bosons and fermions may have taken place before the big bang theory. Then, they were broken into a lower energy particle that we know of at present. To support the idea, the European Organization for Nuclear Research, together with more than 10,000 scientists, built the Large Hadron Collider, now considered the highest energy particle collider globally. But there is not enough evidence to prove the theory. But, let’s hope for the best soon. 

4. Extra Spatial Dimensions

We know that there are three dimensions of space, including length, depth, and width. But there is a high possibility that other dimensions exist. Based on the string theory, the universe operates with around ten dimensions. So why do we not experience them by now? Why do they remain undetected? Professionals report those dimensions are super small to the point that we cannot detect them. 

Why is the expansion of the universe accelerating, though? According to a new study in the Journal of Cosmology and Astroparticle Physics, it is possible that gravity started to leak out to the universe into the other dimensions. But researchers revealed that the gravity remained strong. Thus, different measurements are tiny and do not affect gravity or exist at all. 

5. Multiverse 

Multiverse is another term that you will always encounter in string theory. But what is it? As the name indicates, it is a theory in which multiple universes exist. This is also called a parallel universe. There are several levels of multiverses, according to Max Tegmark, an MIT cosmologist. Level 1 means there is an infinite universe that must have another earth. Level 2 suggests other regions of space with the same laws but unique physical parameters. Level 3 says that other universes exist. Finally, level 4 tells about distinct universes that do not have any connection to ours. 

6. Quantum Gravity and Unified Forces

String theory attempts to combine quantum physics and the idea of general relativity. It is no wonder it is now recognized as quantum gravity. What is quantum physics? It focuses on subatomic particles, atoms, and other most miniature objects. General relativity, on the contrary, is the field of science that examines stars, planets, and other large-scale objects. How about unified forces? How do robust nuclear power, gravity, and electromagnetic energy create a theory of everything? Any interacting strings will be of great help, according to string theorists. 

7. Other Significant Accomplishments You Should Know 

String theory is not the theoretical framework that we are aware of today. In 1968, an Italian theoretical physicist Gabriele Veneziano studied the data gathered from numerous particle accelerators to formulate and establish the string theory’s foundations. Two years after, Yoichiro Nambu, Leonard Susskind, and Holger Nielsen coined the term string theory. In 1974, Tamaki Yoneya, a physicist from Japan, found that string theory consists of a particle with some graviton characteristics.