Every type of string has a unique resonance or 'harmonic'. The strings vibrate at resonant frequencies. Similarly, in String Theory different vibrations from the infinitely small 'rubber bands' result in particles with different characteristics. Different vibration patterns from a violin string each produce a unique sound. In music, different sounds can be produced depending upon where a string is plunked. Many physicists when explaining particle strings compare them to musical strings, as in a violin or other string instruments. See artist BT Wedge's conception of strings at the left. Therefore, if we are ever to prove that strings really do exist they will have to be 'inferred' from other data. That is 10 million billion times smaller than what the LHC can measure. A string element is estimated to be 10^-35 meters in size. The LHC experiments can measure particles down to 10^-19 meters (a millionth of a billionth of a strand of hair). The electron is two picometers, 2 x 10^-12 meters, in diameter. There is no hope that physicists in the foreseeable future could ever measure the size of a string. The most striking feature of String Theory is how small the vibrating string elements are compared to anything in our every day lives. In recent years many new developments have taken place radically improving our understanding of what the theory can some day be. We are therefore unable to make definitive predictions about nature. Bits and pieces of it are known, but we do not yet see the whole picture. String Theory is still under development. But it should also be noted that to date there is no experimental evidence that string theory is the 'basic description of nature'. The strength of String Theory is that it accounts for all four known forces in one elegant theory. String Theory encompasses Quantum Mechanics, The Standard Model (which has been verified experimentally with incredible precision) and Einstein's General Relativity (gravity). Perhaps the most remarkable thing about String Theory is that such a simple idea has such a lot of merit. See the illustration at the left showing some strings that might make up a quark. If String Theory is correct, the entire universe is made of oscillating strings. But if it oscillates some other way, we call it a photon, or a quark, and so forth. If it oscillates one way, then from a distance we see an electron and we are unable to tell it is really a string. A string can do some things besides move - it can oscillate in different ways. But, if string theory is correct, then under an extremely 'powerful microscope' (way beyond today's capabilities) we would realize that the electron is not really a point, but a tiny loop of vibrating string (sometimes called a filament).

Ordinarily an electron is pictured as a point with no internal structure. The bassic idea behind String Theory is that all of the different 'fundamental particles' of the Standard Model are really just different versions of one basic object: - a vibrating oscillating string.

Strings theory font