[tom mccurdy]

This is about as basic as it can come for an Intro to string theory

Tom McCurdy
Mrs. Wynkoop
English 12
12 November 2004
The Quest for the Holy Grail of Physics
String Theory is a theory many physicists hope will lead to the theory of everything.
The theory of everything was something that was even able to elude Einstein for the 3 decades he searched for it. The theory of everything would unite the four forces of our world and our universe; electromagnetism, the strong force, and the weak force. In doing so it hopes to solve one of the biggest conflicts in the history of physics, the conflict between General Relativity versus Quantum Mechanics. However, before examining the current conflict it is necessary to see how we arrived at this conflict. The conflict between General Relativity and Quantum Mechanics is really the third of three major conflicts in physics.
The first major conflict in physics was between predictions made by Maxwell’s electromagnetism equations vs the older Newtonian ideas of the universe. According to Newton if you were able to run fast enough you could quite literally catch up and surpass light in speed. This is not to say that Newton in any way thought it was possible for some living thing on earth to catch up to light, it just meant that there were no laws preventing it from happening. However Maxwell’s equations prevented you from catching up to light. The conflict was eventually solved by Albert Einstein., with the creation of Special Relativity. Einstein’s Special relativity completely revolutionized our view of the universe. It modified it from the classic view of a static unchanging universe to the idea that the universe was actually a malleable construct whose form and appearance was dependent upon one’s state of motion. This is the law that causes things such as Lorenz contraction and time dilation (Joseph McMaster).
It seems like everything should be fine in physics at this point, after all the conflict was solved. However as often in the case in physics, especially in the quest for the theory of everything, one solution leads to a whole new problem. This problem will be referred to as Conflict Number two. Conflict number two stemmed from some of the implications of Special Relativity. According to Special Relativity nothing could travel faster than light, including any sort of influence or disturbance. The restraining of speeds to a maximum of light went directly against what is described Newton’s Universal theory of gravitation, which implies that everything has instant influence on other objects, versus Einstein who said this influence is limited by the speed of light. This second conflict put Einstein’s newly discovered equations against the already respected Newton equations. To really illustrate what the problem is let’s use the common example that many physicist like to use. Hypothetically lets us say for whatever reason the sun explodes. According to Newton the inhabitants of earth would feel its lack of presence instantly and the earth would immediately veer off its elliptical orbit. However according to Einstein the earth would not feel its affect until at maximum around the eight minutes it takes light to reach earth or in other words it is limited to go no faster than the speed of light. It turns out that Einstein was able to solve the problem presented by his previous solution and in doing so he once again revamped our views of the universe. He was able to do something that had puzzled Newton to the point where he simply “feigned no hypothesis.”
Einstein provided an explained gravity with the creation of General Relativity. Now the universe was something that could in fact warp and curve in response to matter of energy, it wasn’t the boring old static place that sometimes comes to thought. Nevertheless, the familiar curse of one solution giving birth to a new problem did not want to be left out of the picture and bore its ugly head once again, and lead to the current problem, the 3rd Conflict general relativity versus quantum mechanics. General relativity governs the world of the very large with its laws, things such as planets, stars and galaxies, while quantum mechanics governs the world of the very small, things like atoms, electrons and quarks. The problem was and still is that both general relativity and quantum mechanics have been proven to work to impressive degrees of accuracy, however mathematically speaking if one of the theories is correct than it forces the other theory to be wrong. They just don’t get along with each other peacefully. The fact at first glance leads many to wonder why a unified theory is even necessary, but there are many situations that would require its existence to examine. The problem is both theories work when you are examining something that requires only one theory, something solely large or solely small. Unfortunately there are many questions in physics that require the use of both equations. These problems are some of the most important mysteries to solve, such as the mystery of the big bang. What exactly happened during the big bang, when you have the mass of the entire universe compressed to an infinitely small point? Should you use General relativity because of the incredible mass or should you use quantum mechanics because of how minuscule the point was. A similar paradox occurs when you examine other things such as black holes where matter is being sucked in by an enormous amount of gravity and being crushed into a small singularity. Which law should you use for either case? The answer is neither. Both theories give non senseical answers. An example of this conflict can be seen when examining some interesting particles in quantum mechanics called spinors (selfAdjoint 3).
Spinors are quite similar to vectors, they have components, however they stop acting like vectors when you change coordinates. However in general relativity it is very important that you are able to change coordinates freely and that the equations describing whatever “physics” you are doing will still be true in this new coordinate system. This is necessary because coordinates determine different frames of reference, different viewpoints. Anything that behaves this way are referred to as tensors, and as you might therefore expect Einstein’s physics is built out of tensors. The conflict arises by the fact that spinors aren’t tensors and they won’t behave like tensors when you change coordinates. A spinor equation will be changed completely. Therefore you could have this spinor representing and electron over here and you look at it from a different frame of reference and it’s a different particle, say a quark (Kaku 2). So that is why we are looking for a solution between quantum mechanics and general relativity we are looking for this theory of everything, something that could describe everything, all of the universes particles and the four forces that govern them; electromagnetism, the strong force, the weak force and the oddball of the group, gravity. And depending upon who you ask in the field we seem to be approaching the resolution to the conflict with various theories. Currently the leader of the TOE wannabes would be something that would completely blow up any idea current perception of the universe, String theory. Sting theory is a predicted theory of everything that makes some radical new claims. When examining string theory at its most basic level it would be easiest to describe it as changing what is believed to be the fundamental constituents of the universe. Instead of the many fundamental particles we have predicted currently string theory predicts that one dimensional loops the size of 10^-34 cm are the fundamental particle of everything (Green 137-152).
The strings in string theory are like those on a guitar for example they can vibrate at different frequencies. Each frequency pattern would represent a different fundamental particle (Woit 3). However in order to do this the string needs more freedom than you or I. Instead of moving in only three dimensions with one dimension of time, strings need more dimensions to work properly. You see as you add more dimensions to our universe you allow for more degrees of freedom. In essence the strings can just do more things. So it was then theorized that we lived in a world with three spatial dimensions one time dimensions and 6 “hidden” dimensions that would be curled up into such predicted shapes as Calabi-Yau manifold.
In the end string theory will remain just a theory until there is experimental evidence to confirm or disprove its existence. The truth is no one knows what the future will hold with the creation of the new particle accelerators like CERN. Over the next 10 to 20 years the way we view the universe is likely to change, whether or not it confirms string theory to be true or not, no one knows. However for the sake of the many physicists who have spent large amounts of time researching it, many hope that it does (Ghitis 1).





























Works Cited


Green, Brian. The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory. New York: Vintage; Vintage Edition, 2001

Ghitis, Jacob String Theory Revisited. Online. 3 Nov 2004. <http://www.journaloftheoretics.com/Articles/201/jg.pdf>

Kaku, Michio A Thoery of Everything. Online. 10 Nov 2004 <http://home.flash.net/~csmith0/theryall.html>

SelfAdjoint Example of Conflict Between General Relativity and Quantum Mechanics. 18 Jun 2004. Online. 11 Nov 2004.
<www.physicsforums.com>

The Elegant Universe. Dir. Joseph McMaster. Nova, 2004

Woit, Peter String Theory: An Evaluation 29 Jan 2001. Online. 1 Nove 2004 <http://www.math.columbie.edu/~woit/strings.pdf>