The String Theory .
The string theory is a concept that many physicists are trying to figure out. It is a theory for an explanation to every thing in the universe, even gravity. The string theory helps our understanding of space time and the force of gravity.
It all started when a scientist, Isaac Newton was sitting under an apple tree one day. An apple fell off the tree onto his head, and he figured out that it was gravity. He said that gravity was the force that kept things on the ground. He thought that nothing was faster than gravity. Einstein did a theory that said nothing was faster than light, and through experiments he proved Isaac Newton's theory to be wrong. Einstein and Newton were constantly butting heads with their theories.
Einstein was one of the first to propose that a theory for every thing must exist, and he put ten years of hard work and long days and nights to attempt to solve it. Today we may be on the verge of cracking Einstein's unsolved mystery theory. It describes a world that might be parallel to ours. When Einstein died, he had been working on this theory day in and day out. He died before he could finish this mind boggling concept.
The strings (or bands of energy) are extremely small, and float around freely. They are not attached to anything. They are so small that they can not even be seen through a microscope. The strings are not made up of anything, but other things are made up of the string. The tiny energy strands are located really deep down in the center of the atom's nucleus.
There are four basic forces in our nature. The most common forces are gravity and electromagnetism, which Einstein and Newton made theories on. The other two are weak nuclear force and strong nuclear force. These forces can not be seen, because they are way deep down in the atom's nucleus. The weak force undergoes radioactive decay, and the strong force helps keep the protons and neutrons bonded together so that they will not separate.