"Think of a guitar string that has been tuned by stretching the string under tension across the guitar. Depending on how the string is plucked and how much tension is in the string, different musical notes will be created by the string. These musical notes could be said to be excitation modes of that guitar string under tension.
"In string theory, as in guitar playing, the string must be stretched under tension in order to become excited. However, the strings in string theory are floating in spacetime, they aren't tied down to a guitar. Nonetheless, they have tension. The string tension in string theory is denoted by the quantity 1/(2 p a'), where a' is pronounced "alpha prime" and is equal to the square of the string length scale.
"If string theory is to be a theory of quantum gravity, then the average size of a string should be somewhere near the length scale of quantum gravity, called the Planck length, which is about 10-33 centimeters, or about a millionth of a billionth of a billionth of a billionth of a centimeter. Unfortunately, this means that strings are way too small to see by current or expected particle physics technology (or financing!!) and so string theorists must devise more clever methods to test the theory than just looking for little strings in particle experiments.
"String theories are classified according to whether or not the strings are required to be closed loops, and whether or not the particle spectrum includes fermions. In order to include fermions in string theory, there must be a special kind of symmetry called supersymmetry, which means for every boson (particle that transmits a force) there is a corresponding fermion (particle that makes up matter). So supersymmetry relates the particles that transmit forces to the particles that make up matter.
"Supersymmetric partners to to currently known particles have not been observed in particle experiments, but theorists believe this is because supersymmetric particles are too massive to be detected at current accelerators. Particle accelerators could be on the verge of finding evidence for high energy supersymmetry in the next decade. Evidence for supersymmetry at high energy would be compelling evidence that string theory was a good mathematical model for Nature at the smallest distance scales." from The Official String Theory web site
Sympathetic Vibratory Physics [see Center Theory] In SVP we do not consider the tiniest atomoles as strings under tension - even theoretical (mathematical) tension. SVP however envisions tiniest possible centers or atomoles about which energy vibrates and oscillates perpetually. A string would vibrate according to Newtonian (linear) (classical) concepts which we know do not apply to quantum and sub-quantum entities. There are however vibrations at these levels of tenuity or subdivision but only according to the Keely and Russell concept of what a vibration or wave really is. Which is to say instead of physical strings there are sympathetic streams of vibration acting in, on and between centers and it is this sympathy as connecting link that connects these dynamic centers or particles. [see entanglement] These centers are governed by the Three Laws of Being and Modes of Vibration and are all sympathetic to each other. [see Atomoles, Sympathetic Vibration, Quantum Entanglement, Sympathy and Love in Science and Physics]
Atomoles alternate of Strings Center Theory alternate of String Theory Dynaspheric Force Etheric Elements Law of Assimilation Laws of Being Laws of Being - Annotated Neutral Center Quantum Entanglement Rhythmic Balanced Interchange Sympathetic Oscillation Sympathetic String Sympathetic Vibration Sympathy The Laws of Being Three Laws of Being Tuning Fork Universal Heart Beat Wave 1.11 - Ultimate Constituents of Matter 3.01 - Law of Matter and Force law of these Strings as centers 14.09 - Brintons Laws of Being