String Theory Simplified

Many of us have heard the term "String Theory" being thrown around lately as the bright new candidate for a "Theory of Everything". But thus far, knowledge of what it actually is has remained sort of murky in the public consciousness. This is probably for two reasons: 1) String Theory is largely incomplete, and so people have been reluctant to devote their energy to try and understand it if it may not be "real", and 2) It does, at first, seem quite intellectually intimidating. However, the purpose, principles and implications of String Theory can all be easily understood without invoking any complicated math or physics. Additionally, even if String Theory turns out to be an elegant yet woefully misleading conjured up picture of the world, knowledge of the story will grant you comedic hindsight of the irony of how some physicists will follow their theories, no matter how wild or outrageous, as blindly and stringently as people of religion (whom some mock) follow their book of faith.

String Theory is an attempt to unify and explain the origin of all the laws of physics. It tries to uncover what the smallest, most fundamental, indivisible constituents of our universe are. Reflective of its name, String Theory proposes that these constituents are infinitesimal vibrating strings, and that strings vibrating in different ways produce the different elementary particles that we observe. For instance, a collection of strings vibrating in one way produce an electron, and a different collection of strings vibrating in another way produce a proton. A great analogy to help understand this concept is by considering a string instrument such as a guitar. Different strings at different tensions strummed in different ways give rise to different musical notes. So, the strings in String Theory are like the strings on a guitar, and the different particles produced by the strings in String Theory are like the different musical notes produced by the strings in a guitar. To take the analogy further, a collection of musical notes produce a song, and a collection of particles produce a universe.

At this point most of us will be scratching our heads a bit at this concept. But although it may be a little difficult to accept that our universe might be made up of a bunch of tiny strings, it generally seems like it could be within the realm of reason. Here is where String Theory wholeheartedly parts from reason.

As we know and experience it, the world is a four dimensional place. It has three space dimensions (up and down, left and right, forward and backward) and one dimension occupied by time. All of the known physical laws work and operate within this four dimensional framework. However, the mathematics of String Theory lead us away from our four dimensional familiarity. The math of String Theory does not work in four dimensions. It does not work in five dimensions, nor six, nor seven. Only within an 11 dimensional framework, with ten space dimensions and one time dimension, does the math of String Theory work out.

An inquisitive person should immediately have two questions to ask String Theorists about these "extra" dimensions: 1) Where are they and why can't we detect them and 2) Is there a way to prove that they exist? String Theorists' answer for the first question is that these ten space dimensions are curled up within the three that we already know about, but they are so small that they elude detection. It is similar to how when viewing an object from far away it seems to be only two dimensional, and only when we approach closer can we see that it is three dimensional with depth. String Theorists also believe that the specific shape of these dimensions is responsible for determining the intrinsic quantities of the universe, such as the values of the force of gravity and the mass of the electron.

The answer to the second question is thought to be yes, and excitingly, the ability to conduct the test may come within the next few years. At the Large Hadron Collider (LHC), the most powerful particle accelerator ever built, located at CERN laboratories in Geneva, Switzerland, scientists are almost ready to boost the machine up to energies that will allow for the testing of extra dimensions. Scientists think that if they are able to smash particles together at high enough energies, some debris from the collision might escape into an extra dimension. To test for this quantitatively, they will calculate the energy before and after the collision, and if there is less energy present after the collision than before it, it may indicate that this missing energy has relocated to an extra dimension.

Now, as mentioned earlier, String Theory is currently incomplete and a bit messy. There are actually several competing versions of String Theory, and some think that the best that an ultimate theory can ever do is combine overlapping parts from each of the different String Theories. Furthermore, String Theory is one among several other candidates for a "Theory of Everything".

Scientists may be getting a little ahead of themselves in declaring that we are close to such a grand achievement. As much as scientists accuse people of religion of allowing faith to blind them from reason, scientists are susceptible to a similar flaw - beauty often blinds them from truth. If history has taught us anything, it is to take any feat of science with a grain of salt, for it always seems that there is more to the puzzle waiting just around the corner.