Theory Of Everything, The
Imagine a world in which everything is explained, in which human beings would know why they act, how they think, and how they came to be. A complete understanding of the entire universe would flow from one single equation: a grand unified theory. Finding such a theory has been the dream of physicists since the idea was first proposed by Isaac Newton, and lately, with technological advances bearing such names as particle accelerators and supercolliders, science is getting closer and closer to finding this theory. Along with the knowledge, however, comes speculation and debate. Some scientists do not see the need for a grand unified theory, sometimes dubbed a "theory of everything". However, such a theory would offer insight into nature and the forces that shaped our lives. The search for a grand unified theory is an important and potentially valuable step for all humankind.
The search began with Isaac Newton. He first proposed the idea that one great theory might exist that would link all the other known theories. This theory would provide one blanket statement that would describe everything in the entire universe, known and unknown. Other physicists, starting with Albert Einstein, began searching for this grand unified theory, which, through their love of acronyms, they affectionately called GUT. Some even started calling it a theory of everything, which led to the acronym TOE. They started with four basic forces: the gravitational force, which Newton had earlier found to explain gravity; the electromagnetic force, a linked theory of electricity and magnetism; the strong nuclear force, which holds the nucleus of the atom together; and the weak nuclear force, which is involved in the decay of atoms. In 1979, Sheldon Glashow, Steven Weinberg, and Abdus Salam combined the theories of electromagnetic and weak interactions into the electroweak theory (Elementary Particles). This was a gigantic step toward a GUT because it showed how two of the four main forces could be linked together with theories.
Theories are not enough for physicists, though. They are looking for tangible particles to explain and give concrete proof for the theories. The probability of finding new particles is growing as elementary particle physicists are gaining the ability to smash atoms together at incredibly high speeds. This is done in particle accelerators and supercolliders, which are large devices built to accelerate individual particles to almost the speed of light. The particles are then placed in line with other particles. The two bits of matter collide and produce astounding results; they are either broken into component pieces or fused together to create bigger, more massive particles. Both outcomes can be studied to provide more insight into the realm of the infinitesimally small.
Plans for the world's largest supercollider are now being developed by the Conseil Europen pour la Recherche Nuclaire, known in America as CERN (Dawson). This would be the furthest step ever taken by scientists, and the supercollider would have the capabilities of accelerating particles to faster speeds.
Protons are often the particles accelerated, because of their small mass and relative stability. They are smashed into antiprotons, the particles with characteristics exactly opposite those of the proton. The second choice of particle physicists is the electron, being almost massless and easy to accelerate, smashing it into its opposite particle, the positron.
All this accelerating and colliding was meant to prove the existence of some fundamental particle, something which was the building block of all matter and could not be divided. Several hundred new particles were found, most of which could only exist within the stability of the accelerator. Some physicists, though, likened the finding of this array of particles to unscientific studies. In describing supercolliders, Victor Weisskoph analogizes, "If you want to know what is inside two Swiss watches, you bang them together as hard as you can and see what comes out" (Fisher). However unscientific, this "banging" has proven fruitful to scientists. They have found that in all the new particles they created, there were only twelve basic particles, called "matter particles", which form everything known to humankind. They have also found several messenger particles, which carry the forces between the matter particles, and physicists hypothesize about more elusive messenger particles, like the yet undiscovered graviton, thought to carry the force of gravity, which they cannot create as of now. The direct result of all these studies is that scientists have taken the data and proposed a Standard Model, a "collection of theories that are brilliantly successful at delineating all the known truly elemental particles and their interactions" (Fisher).
The Standard Model proposes a set of theories that explains the forces and the interactions between particles. These theories are basically accepted by physicists as accurate in describing the known universe. For most, however, even though they accept the Standard Model, they feel there is more to be discovered.
There are two main theories that are used to describe everything; general relativity, proposed by Einstein and describing gravity as a result of curvature of space-time, and quantum mechanics, which describes force in terms of little packages (Bartusiak).
Physicists are searching for a GUT to describe all the known and unknown with one unified equation. Marcia Bartusiak likens making these two theories compatible to "bowling with tiddlywinks" or "jump-starting a car with an eggbeater". To create a bridge between these two theories, some physicists have developed new hypotheses. One such hypothesis is called string theory.
String theory proposes that at the "Planck length," ten to the power of -33 centimeters, smooth space-time dissolves into tiny vibrating loops called strings (Odenwald). These strings comprise the entire universe and everything in it, including space-time itself. The strings are identical, but depending on how they vibrate, they form everything in the universe: quarks, electrons, neutrinos, and all other particles (Taubes, A Theory of Everything).
The only catch to this theory is that it requires the strings to vibrate in ten dimensions (Kaku). In our known world, there are four dimensions: three of space and one of time. Physicists are just beginning to learn how to work in the extra six dimensions essential to string theory. They call this six-dimensional space "phase space", and roll the dimensions up into tiny objects called "Calabi-Yau compactifications" (Cole). With these six-dimensional compactifications, though, comes a multitude of four-dimensional solutions to the theory. The main goal of physicists now is to choose the correct one that corresponds to our universe.
String theory holds much potential for physicists, but it is complicated and confusing, and thus has driven many scientists out of the field. In a new variant on string theory, black holes and strings are shown to be fundamentally alike, evolving into one another during a crucial point in the theorems called a "phase change" (Taubes, How Black Holes). These phase changes also link the Calabi-Yau compactifications, previously thought to be distinct entities. So-called dark matter, or "sparticles" (short for super particles) also helps string theory (Kaku). Sparticles serve to reduce the number of four-dimensional possibilities to string theory and make it considerably easier for physicists to find the real-world equivalent to the hypothesis (Peterson, Strings and Webs).
Michio Kaku insists that ten dimensions are necessary for string theory, because no fewer than ten dimensions can account for both general relativity and quantum mechanics, but Stan Odenwald maintains that it is possible to build working GUTs within four-dimensional space-time.
A separate theory, but still along these lines, is called supersymmetry. Supersymmetry maintains that there is a constant underlying symmetry between everything in the universe, that everything is alike underneath its appearance to humankind. Like string theory, supersymmetry includes more than the normal four dimensions that have been accepted by scientists. It is known to physicists that symmetry helps unify theories, and more dimensions means more symmetry, so there is a greater chance with supersymmetry that the forces can be linked together (Cole).
Neither of these theories, string theory or supersymmetry, can by themselves form a GUT, though, but physicists have made some progress linking the two to form a completely unified GUT. These theories linked together is called superstring theory. According to David H. Freedman, string theory is a "natural foundation" for superstrings, which are strings having the properties of supersymmetry. They are the same underneath, but depending on the frequency at which the superstrings vibrate, they can form particles or even forces. The symmetries of the particles can be glimpsed in proton collisions in particle accelerators. The collider at Fermi National Accelerator Laboratory in Illinois has produced, by means of a proton-antiproton collision, results that fit the assumptions of supersymmetry (Peterson, Hint of Supersymmetry). Supersymmetry looks to be the most promising road to a GUT.
Despite the lure of a true GUT, many people oppose the principle behind such a theory. Fundamentalists in particular are against it, saying that a GUT will undermine faith and religious beliefs. They have traditionally been opposed to anything that even slightly deviates from the bible, believing instead in its literal interpretation, including the story of creation. They do not accept the big bang theory or the theory of evolution.
However, some physicists say that religion and science are compatible. John Polkinghorne states that many people presume science is atheistic, but in fact, science asks the question "how", and leaves the following question, "why", up to the individual.
Fundamentalists also believe that if a GUT is found, humanity might find no reason at all why they exist, and will lose all conscience. Steven Weinburg counters: "... if the laws of nature cannot give us a sense of conscience, neither can they take it away". He continues to say that some religious beliefs are inappropriate in this age of science and technology, and science's greatest service to humanity might be to take away those "childish" beliefs and help humanity "grow up".
The apex of the debate, however, is reached by Polkinghorne and George Greenstein, who say that our universe could not exist without the careful balance of the forces. If the forces were not exactly the strength they are, human life could never have evolved. Everything in the creation of the universe, Polkinghorne says, is so "finely tuned" that those who choose to believe in a creator have plenty of room alongside scientific theory to see threads of intelligence, or God, behind the seeming chaos of the creation of the universe. Science and religion can not only co-exist, they can thrive off each other.
Science has come a long way since the time that Isaac Newton first proposed the notion of a grand unified theory. Supercolliders and other particle accelerators have shown elementary particle physicists a whole new world of particles, and they have been able to show that only twelve of these make up everything in the known universe. They have found many particles also that do not exist under normal conditions, but that pop in and out of the vacuum of space to carry the basic forces. Physicists have been able to create theories like the string theory and supersymmetry to explain these events, and have unified the two to create superstring theory. Science has taken a lot of flack for its search for a GUT, but many physicists argue that science and religion are completely compatible. The search for a grand unified theory is indeed a valuable one, and should be continued in order to further the understanding of all humankind.
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