Survey:
1) Do you think you know what string theory is?
Yes- 0 Kind of-1/12 No- 11/12
2) Do you know what elementary particles are?
Yes- 0 Kind of-1/12 No- 11/12
3) How often do you hear about string theory?
Almost never- 12/12
4) How much do you know about the fundamental property of string theory?
Nothing- 12/12
Yes- 0 Kind of-1/12 No- 11/12
2) Do you know what elementary particles are?
Yes- 0 Kind of-1/12 No- 11/12
3) How often do you hear about string theory?
Almost never- 12/12
4) How much do you know about the fundamental property of string theory?
Nothing- 12/12
Explanation:
The break down of elementary particles into a single vibrating string of energy, each elementary particle has their own vibrating frequency, much like how a note on a violin has different vibrations that produce a corresponding note. String theory is a universal scientific theory of everything. It unifies the 4 fundamental forces, also known as: Quantum Mechanics (Weak and strong nuclear forces, and Electromagnetic forces) and gravitational forces.
Further Explanation:
String theory states that everything is made up of a string, or "string" of energy vibrating at a certain frequency to produce a certain elementary particle. String theory is a candidate for a theory of everything because it unifies Gravitation, Electromagnetic Forces, and Quantum Mechanics (Electromagnetic Forces may be classified in here too). The problem is laws of nature (the four fundamental forces) do not comply with each other, string theory seeks to solve that by unifying those forces into one single theory.
Super-string Theory states that there are seven higher dimensions, and the four conventional dimensions. (3D+time+7HD = 11D), time is included in the 4 conventional dimensions. These 7 higher dimensions of course are not visible to the naked human eye, or by any of the technology we have today. (Physicists have though to test the theory of extra dimensions by using the Large Hadron Collider in Switzerland, they intend to measure collisions and the loss of energy into another dimension, this would follow the principal of energy is not created or destroyed without a "parent" action). String Theorist believe that these other 7 higher dimensions are curled up into balls and act as a type of membrane that the vibrating string of energy acts on, giving us different elementary particles for each unique vibration of a string, which produce what we know as the standard model.
Standard Model:
Super-string:
There are five different popular super-string models which have 10 dimensions + time, all of them having different mathematical models but refer to similar classifications, Type I, Type IIA, Type IIB, E8xE8 (Heterotic), and SO(32) (Heterotic), collectively known as M-theory. These models are are either open/closed (open ended string models have free ends, and closed ended are joined into a complete loop), and are either oriented/non-oriented (meaning that one may tell which direction they're traveling a long the string, or if they're non oriented one cannot tell what direction they are going), and the number classification of space-time super-symmetry charges.
Popular Super-string Models:
Type I: Open (plus closed), not oriented, 1 space-time super-symmetry charge
Type IIA: Closed, not oriented, 2 space-time super-symmetry charges
Type IIB: Closed, oriented, 2 space-time super-symmetry charges
Heterotic E8xE8: Closed, oriented, 1 space-time super-symmetry charge
Heteroric SO(32): Closed, oriented, 1 space-time super-symmetry charge
Why 11 dimensions? According to Dr. Michio Kaku that the mathematics behind string theory prefers to be in 11, when introduced to any dimensions above or bellow, the models become unstable. These are not visible by us because they are said to be smaller than a Planck length (1.616x10^ -35) meters. These higher dimensions are thought to be curled up into balls creating membranes of a string.
Bosonic:
There are also 4 popular types of bosonic models which have 26 dimensions + time. They are classified as being open/closed and oriented/non-oriented. Bosonic theories are all unstable because of the ground state, which comes down to scalar tachyons. Which would cause the total 27 dimensions to collapse down to super-string theory's total of 11 dimensions because of instability.
Popular Bosonic Models:
Open (plus closed, oriented)
Open (plus closed, non oriented)
Closed (oriented)
Closed (non oriented)