String Theory
Einstein's final quest was to find a formula that unifies his theory of Gravitation (General Relativity, based on Newton's advances, hundreds of years earlier) and the already unified theory of "Electro-Magnitism."
General Relativity is a theory that explains the laws that govern the universe on a large scale, such as the force keeping a satellite in orbit, which are mathematically correct. The Standard Model is the group of three theories (not quite unified) of EM, Strong, and Weak Nuclear Force, which are scientifically verifiable in the laboratory. A discrepancy between the two theories prevents the two from being unified in the forms that they stand as-is. There are examples, such as a cosmic Black Hole, where one theory explains the event as something occurring on a large scale, and the other theory identifies with the molecular scale.
A unification of General Relativity and Quantum Mechanics would be a huge advance in human knowledge of the universe. Ideally, the unification would be a simple formula joining both theories in a clean-cut fashion. This unification could provide a result that would be able to explain everything in the universe, indeed our own existence.
In order for the two theories to unite, discrepancies between them must be explained logically. This would also mean that a formula used to calculate something on a cosmic scale could also be used to calculate something on a molecular level. Also, the laws, or general concepts of reality should exist in both scales in the same way. On a quantum level, the everyday concepts that we are accustomed to, do not always unquestionably hold true. If our everyday life was like the quantum universe, we would not be able to predict the outcome of anything, and anything that requires stability would be useless.
How can a universe so unpredictable be able to be mathematically predictable using the laws that we have become accustomed to using? Short answer: it can't. The implicit unification between Quantum Mechanics and General Relativity produces errors in itself from the beginning. Unsuccessful unification of these two completely different theories was attempted in the years after Einstein's death in 1955.
The difficulty of unifying these two theories is now believed to be due to the fact that our understanding of the universe, the basis by which we constructed Quantum Mechanics and General Relativity, are conceptions rather than reality. Indeed even Isaac Newton did not understand what gravity is, but was able to identify what gravity does. Additionally, it was once believed that the universe was geocentric, and even though it only appears to be, the misconception would not be noticeable until such strange occurrences (i.e., discrepancies) such as Mars' retrograde, and Galileo Galilei's tracking of the Moon's of Jupiter. The Geocentric theory of the universe was contradicted by such astronomical observations, just as Quantum Mechanics contradicts General Relativity. The only solution to such a problem is a reexamination of what we actually know; hence, the world of String Theory.
The world as we know it, a world of clearly defined rules governing clearly defined objects, is made up of assumptions. We assume that gravity operates in a certain way, and thus we are able to predict and base formulas on reliable predictions of objects being effected by the force that we call gravity. But what if gravity is something completely different? What if it is coincidental that our formulas are successful only because they are part of a larger
[complicated derived]
formula where all the other variables are mathematical identities under the experiments that we have performed? Surely adding variables to the "quadratic formula" do not effect the result if their coefficients are zero. Perhaps our understanding is based on basic assumptions that need to be reexamined.
String Theory, a theory that says that everything in the universe is made up of tiny strings of energy, vibrating at different frequencies, is an attempt to unify what we know of both the quantum universe, and the classical universe. Starting by explaining the chaos of everything of a quantum scale, String Theory is able can theoretically explain the discrepancies that plagued the implicit unification between Quantum Mechanics and General Relativity after Einstein's death in 1955.
For many, String Theory becomes questionable when it is learned that for the theory to be correct, there must be eleven dimensions. Many individuals know that there are only four dimensions: X, Y, Z, and time; they too, could also be wrong. Time itself is not a physical dimension; you cannot touch time, you cannot move time (at least not as you can move in "X-Y-Z"). Should someone not understand the fourth dimension (time), they would find abnormality in the concept that an object is continuously moving through the fourth dimension without moving at all in "X-Y-Z." We cannot manipulate time in the same way we can move an object; we are limited to a constant, continuous movement, which is self-sufficient (i.e. we do not need to wind it up or add batteries). Similarly, there could be an additional dimension that does not require physical interaction to operate, or perhaps even six (or seven) more as required for String Theory.
If everything is made up of strings, than String Theory could unify everything we know about the universe, and even provide a means where we could understand much more about our existence. It not only would simplify what we know, but it would expand our knowledge, allowing us to make discoveries indirectly. Humankind, obviously, cannot regress to the point in time of the "Big Bang" in order to learn what actually occurred, but a "Theory of Everything" could make this task an unnecessary journey.
In order for String Theory to be considered a theory, it simply must hold true using a theoretical basis. By setting certain specific limitations, it must explain (theoretically) both why there are discrepancies between the quantum and classic universes, as well as how the universe actually (theoretically) functions. For as long as strings are theoretical, String Theory is only a philosophy. For String Theory to be considered a law of the universe, there must be a way to scientifically verify its validity in the laboratory. Currently, it is not possible to study strings directly; they are too small to view under a microscope. Future discoveries and advancements may bring to life technology that can either study a string directly (a very high magnification microscope), or study a string indirectly (the ability to isolate the effects of a string).
Einstein spent the last years of his life attempting to find a "Theory of Everything," a theory that could explain every question about the universe, but was unable to do so because the foundation by which he based all his attempts, may not have been correct. String Theory, a theory uniting what we know of Quantum Physics and Classic Physics, uses what is believed to be the building block of the universe (strings) as the base of all its assumptions. String Theory is an attempt to build a new understanding of the universe from the ground up (literally, the very building blocks of the universe). Through this new approach, it may be possible to solve the problem that baffled Einstein during the last years of his life.
As String Theory developed, the brightest within the field developed five different versions of String Theory, each using the same starting point: tiny vibrating strings. This caused a dilemma; why would a theory, whose main function is to simplify our understanding of the universe, be in the form of five different mathematical theories? Edward Witten, a leader in the field of Physics, took String Theory and attempted to determine which of the five theories of strings was the correct one. The final result was that all five were correct; each of the five theories were a different way of conceptualizing the problem.
Witten also determined why String Theory requires ten dimensions. Dimensions one through three are the well known X-Y-Z coordinates, the fourth dimension is time, and dimensions five through ten are "Degrees of Freedom," allowing for all the string's needs to be met. Witten also added an eleventh degree; a degree of stretching of the membrane (also called the "Brane"). With these eleven dimensions and the five string theories that were grouped together, "M Theory" was born.
If M Theory is correct, we are living in a universe where we cannot see half of the dimensions that exist. This limitation has been compared to being constricted to the surface, the membrane even, of a complex universe. Trapped on this membrane, we have been limited to the way in which human-life has progressed in the thousands of years of our existence; but with the knowledge of how this Brane works, and how we can interact with the seven additional dimensions, we may be able to defy what we currently think of as reality. We currently may only be trapped by the fact that we do not know how to interact with our surroundings.
In order for the M Theory to be an acceptable explanation of the universe, it must be experimentally proven in a laboratory. To do so, Fermilab is in the process of smashing hydrogen atoms at near light speed in an attempt to track what is known as a "Graviton" as it escapes from the hydrogen atom and leaves the Brane that we know. A Graviton is a type of closed string that is believed to be responsible for gravity; a Graviton may be the very definition of gravity itself. As two hydrogen atoms smash into each other, the atom breaks apart into all of its components, which can be tracked. Hopefully, one day, the Graviton will appear as one of the components, and will be detected as it leaves the Brane. At least one other, more powerful, "Atom Smashers" is being built in the quest to find the elusive Graviton.
Work Cited:
NOVA's "The Elegant Universe"
http://www.pbs.org/wgbh/nova/elegant/
M-Theory, the theory formally known as Strings
http://www.damtp.cam.ac.uk/user/gr/public/qg_ss.html
String Theory
http://en.wikipedia.org/wiki/String_theory
Fermilab Research
http://www.fnal.gov/pub/about/experiments/index.html
