The String Theory
In the 1600’s of old England, a lone man sat under a tree, when an apple had fallen onto the ground. He then came to wonder what force was being used to pull this apple and any other piece of matter to the ground (Fowler). This man was considered by many as the grandfather of physics with his theories on gravity showing that this was the force that was applied to keep all the planets in orbit. Let’s take a step in a different direction before moving on to more of the complexities of the gravitational force.
Life as we know it has three spatial dimensions, up to down (height), left to right (length) and back to forward (depth). It also has the dimension of time that is intertwined into the three dimensions and interacts dependently on these.
As an object travels at a speed across the spatial dimensions, it effects the way the object experiences time, and the faster the object travels the more of a pronounced effect of time ‘slowing down’ it experiences (Greene). For example, let’s say I have an ultrasonic jetpack traveling in the endless depths of the universe, and I left my second watch back at home. I’m flying through the universe at speeds about 80% to those of light to return home to get my other watch because I need two of them. When I return home I come to realize that my watch is off. The watch I had on my wrist was almost an hour behind the watch I had left at home. Perhaps I missed daylight savings time, but I checked my calendar and came to the conclusion that this was not the case, and in fact I had traveled at such speeds through the space-time dimension that I had experienced time slower than that of my watch sitting at home.
One more prospect of the relation of motion and space-time is that to a stationary observer objects in motion appear shorter as their speed increases (Greene). Let’s say I’m back flying in the depths of space and catch a glimpse of an object as it passes. It was a video camera that recorded my actions. Upon returning home, I remember that I had placed a video camera in the area on one of my previous journeys through the sector in space and called upon my VCR to playback what it had recorded. Sure enough there I was for a millisecond speeding through space. However it did not look like me. I did a few scale measurements of myself and the film footage and realized that on the film I was 80% my original length.
But there are always speed limits for everything. Even though I’m traveling in the depths of an ungoverned territory, there is still a speed limit. This limit is the speed at which light travels, or 299,792,458 meters per second. In fact no matter can travel faster than this speed. As the speed of an object increases the weight increases (Greene) and keeps increasing until it comes close to the speed of light. Matter cannot travel at the speed of light, however, because as the weight increases as does the amount of energy needed to travel at these speeds increases. So one could get up to 99.998% the speed of light but the little push required to go the speed of light would require an infinite amount of energy (Greene)
Gravity was revolutionized by a man who called himself Albert Einstein. He showed that gravity was not just a force tying all objects with each other in the universe in his theory of relativity. He showed that large objects actually create a dip in the fabric of space (Greene) much like that of a bowling ball on a Temper-Pedic mattress.
Recall back to Newton’s thoughts on gravity and its properties. He believed gravity to be a constant force and if the sun were to ‘die out’ and lose it’s gravitational field, then the planets of our solar system would continue in a straight line until another force acted upon it. This does not match up with our common conceptions of the universe. Albert Einstein realized this and puzzled over the situation to realize that if the sun were to ‘die out’ it would actually send a ripple in the fabric of space like a rock dropped in water (Greene). This is because nothing can travel as fast as light, not even the force of gravity.
Introductions into the realm of quantum mechanics showed an incompatibility with the forces of gravity. Direct conflicts were made between the microscopic world and the large mass world.
Light travels in packets, or quanta, of photons, a particle that composes light (Greene). A common experiment to test the properties of light as photons is through sending these packets of photons through a vertical slit with a piece of photosensitive paper at the opposite end to collect packets of light. When you have a piece of material that the beam is being projected through, the light would shine through the slit and create a vertical display of light. But when we put two slits next to each other and shine the light on the material, we come up with results that may be troubling. You may think that it would project two slits resembling the ones in the material. This is not true, however. In fact, the light from the two slits interfere with each other causing a series of vertical lines of light to be displayed. This shows that light has properties similar to those of waves (Greene). When the two beams are sent through the slits, they create a jostling, like those of an oceanic wave crashing onto a shoreline rock.
The atom is composed of three 3 basic parts with different charges, the electron (negative particle), the proton (the positive particle), and the neutron (the neutral particle). The neutrons and protons are packed in the nucleus of an atom held together with gluons, the messenger particle of the strong force (Greene). A messenger particle is a particle that when passed between to particles they interact with each other. At the heart of each particle is a particle known as a quark (Greene). Quarks come in different “colors”. They are known as colors but are not actually colored; the color code is just used for classification (Greene). Each color decides how the specific quark acts. There is a force known as the weak force that is used for the quark to change ‘color’. This force was found in the presence of radioactive decay and more specifically in beta decay(that one website). There is another force that holds atoms together known as the electromagnetic force and found in the movement of photons of light (that one site). The electromagnetic force is based on the principles of magnetism and electric charge. Since like charges repel each other and unlike charges attract each other, the atoms are held together by the negative electrical charge of one atom’s electron attracting to its proton. In the electromagnetic force, when messenger particles are transferred, the atoms become closer together due to the magnetic effects (Greene).
But the facts of the large world break down with the quantum world because if we were to shrink down into the size of the quantum level we would see a vast difference. According to Einstein’s theory of relativity, (the laws that describe gravity), the universe is a smooth free flowing area where planets flow on the warps of the fabric of space. But according to quantom physics, on the tiny levels we see that the fabric of space is a wild unpredictable place where the fabric is being jostled on a constant basis (Greene). It was impossible to tell where something was at a certain point in time or even when it was there (Greene).
The concepts conceived in the small world forces did not agree with the large forces of gravity. Scientists saw that and figured they needed to devise a way to unite the two concepts to be universally compatible. In the late 1960’s, Leonard Susskin stumbled upon The Gamma Function, which was written by Leonard Eueler and described the strong force, he put it through many mathmatical tests and found the equation was describing strings that could stretch and wiggle (Greene). He submitted a paper explaining the equation of the string theory. His ideas were mocked and denied. It was over a decade later till his work was rediscovered by John Schwarz and worked on an equation to solve the values of the string theory. When he came up with the equation, there were a number of anomalies in the equation and the fact that it included a mass less particle, so at first it was disregarded. Then after several months of work, he thought maybe the mass less particle was describing gravity (Greene). This caused him to change his thoughts of how small the particles were. There were still anomalies in the equation so is was once again denied for publishing. He had to fix out the anomalies and worked on it. When he tested his anomalies and plugged his numbers into his new equation, it was correct. The publishing of his workings caused an outburst in the physics community raving about the new theory of everything, but this was not the end of string theory. The social community did not accept it fully due to the inability to find a mass less particle.
Scientists had to look to a strange concept that seems crazy or even unreal to people. This is that there are extra spatial dimensions in the fabric of space (Greene). Like a mat of carpet, from an overhead view it only appears to be a flat surface, but when I kneel down to look deeply at the carpet I find a loop of fabric connecting to the bottom surface of the carpet. This is much how the other dimensions of the universe are described in the string theory. In fact there is not just one extra dimension, but six extra dimensions making a total of ten dimensions. These dimensions are intertwined in a strange manner on extremely unimaginable magnification. The strings in string theory move around on these extra dimensions and the dimension controls the way the string vibrates and the shape the string has (Greene). How small are these strings you might ask. Well if you were to enlarge an atom to the size of the universe, a string would be the size of a tree on earth (Greene).
Once again there was a snag in the line of complete physics. This was the fact that there were five different equations to the string theory that were different (Greene). So the question arrived, if all these equations were correct, then which one described our universe. In 1995 Edward Witten devised the thought that all 5 equations were correct and just different ways of looking at the strings (Greene). This was known as the M theory. Witten’s ideas were based on there being an 11th dimension (that other site). This theory said that our four dimenion world we live in is mearly a membrane in a larger 11th diminsion. The membranes come from strings (Greene). According to Witten, the 11th dimension provides the string the ability to form into a 3 dimensional object called membranes. With the aid of energy, these membranes could grow to the size of a universe showing a higher dimension composed of these branes. This says that we might be living next to universes called parallel universes (that other site). These places could have matter and objects but might follow completely separate rules of nature. The M theory also proposed open ended strings that tie down to our 3 dimensional space to compose all of matter and light as we see it (that other site). But there are also enclosed loops of these strings called gravitons, these strings having no closed ends are free to move into the upper dimenison (Greene). That would mean an ability to communicate via gravity to other universes if in fact there is intelligant life and they have the same technology (Greene).
The M theory is not limited to unification of the forces. It might also explain in the very depths of time how ideas like the big bang occoured. String theorist proclaimed that in the higher dimensions, membranes could collide with each other creating such a transfer of energy that would send a spray of matter hurling through the universe (Greene). They also said that this might have happend several times. But of course these theories can not be tested with conventional scientific knoledge.
Scientists struggle with their findings due to the insanely microscopic size of strings. They have been working on trying to see one of these gravitons as it leaves the dimension of our reality and travels to the higher dimension, but have failed in seeing one so far. Answers of life’s many mysteries could be solved with string theory. A time frame for when these concepts will be proven is unknown, but as long as the ideas of knowledge poke at the minds of the human race, there will be people testing and trying to find the answer.
