The discovery of the concept of gravity dates back to Isaac Newton in 1687. This was only the beginning and little did Newton know that his findings were the background of modern physicists research. Albert Einstein created his theory of general relativity and spent the rest of his life searching for the answer to combine general relativity and quantum mechanics in a new theory of unification. He needed a mathematical equation that described the four fundamental forces and a concept to combine all the laws of the universe. Modern physicists are working on String Theory, which is said to hold promises to answer complicated question and may be the answer to the theory of unification, if it can only be proven.

### General Relativity

General relativity is a proven theory created by Albert Einstein to describe how gravity works. Einstein went off of Newton's discovery of gravity and established his own theory. Based on general relativity, nothing can go faster than the speed of light and gravity is fabric force that can be stretched and warped to create the feel of gravity. Originally, Newton thought that gravity was instantaneous, meaning if the sun suddenly disappeared, the earth would go immediately out of orbit. Although, as it turns out, Einstein proved that it would take 8 minutes for the wave of the sun disappearing to hit the earth.Einstein also discovered "Space-Time", the 4 dimensions we know of today. They are length, width, height, and time.

### Quantum Mechanics

Quantum Mechanics is all about probability and predicting the outcome is the best you can do. It describes the way the world works at the microscopic level. It deals with the behavior of matter and light and its interactions with energy at the atomic level. It describes the question of whether light is a particle or a wave. Quantum Mechanics has been stumping physicists for decades and is a pretty difficult concept to comprehend. Experimenting at the atomic level can prove to be rather difficult.

### Four Fundamental Forces

The four fundamental forces of the universe are gravity, electromagnetism, strong nuclear and weak nuclear. Contrary to popular belief, electromagnetism is billions and billions times stronger than gravity. Actually, gravity is pretty weak. For example, gravity is the force keeping you on the earth, but you can easily jump against the force of gravity. Strong nuclear force is the force holding the nucleus of an atom together and weak nuclear force is the force that is responsible for radioactivity. Weak nuclear allows protons to turn into neutrons and give of radiation. The laws of the large correspond with gravity but the laws of the small correspond with the other three forces.

### Unification

Unification was the theory that Einstein died trying to figure out. He wanted to create a law or mathematical equation that combines all the laws of the universe into one idea. Since Newton combined heaven and earth, Einstein wanted to combine everything else. The math of Quantum Mechanics and General Relativity don't coexist very nicely. This new theory would need to explain the four fundamental forces, but most importantly, it would need to combine the mathematics of all of them. This new theory called string theory may be the answer we have been looking for, but there are a few complications.

### String Theory

String theory is said to be the universe that combines science fiction with reality. It tries to describe gravity at the quantum level and it said to be vibrating strands of energy that vibrate in a multitude of different ways. They vibrate at different frequencies to create everything. It holds promises to answer complicated questions and is nicknamed "The Theory of Everything". Originally, there were 5 different versions of string theory, but it has been combined into 1 theory called the "M" Theory. Although, there are a few problems with this theory. If String Theory is correct, it suggests that there are 10 or 11 dimensions in our universe, instead of the 4 we know of. In addition, these strings of energy as so small (10^-35m) that it may never get any experimental evidence.

Credits:

Created with images by Sweetie187 - "space" • Windslash - "Galaxy"