The reality is wider than our common sense. Instinctively, described as "madness" or "outrageous speculation" to scientific theories that propose a far cry from our experience. But over time, and if the theory is consistent, we drop our guard and we end up ideas that transcend us. This is what has happened, to some extent with string theory.
Strings, "a key to unficación of
forces? (Source: smartplanet)
The dream of physics is to find an explanation easy for all physical phenomena. If achieving that dream goes without saying that there are eleven dimensions, never mind. The drivers of the strings do not seem very wise fear. They know that the award exceeds the price. And the prize is the unification of all forces.
In the universe, there are four fundamental forces. The theory of relativity Albert Einstein explains one of them: gravity. The standard model of quantum mechanics explains the other three: the electromagnetic, strong nuclear force and weak force.
- The four forces of the universe (Smart Community, available soon).
- The four forces that move the universe Networks (286).
As formulated, these two great theories (relativity and quantum), each one implies the other is invalid. However, both theories have been corroborated in numerous experiments. How is this possible? Just because the theory of general relativity describes phenomena that involve very large or massive bodies such as galaxies, solar systems or the same universe. Quantum mechanics, in turn, describes small objects such as molecules, atoms or subatomic particles.
So why try to find a unified explanation for both theories, a theory that explains both the gravity and the other three fundamental forces? In fact, physics is proceeding without problems using general relativity and quantum macro to the micro ...
The world of macro and micro. (Source: smartplanet)
On the one hand, large objects are made by small and illogical that some have about laws and other objects, different laws. On the other hand, there certain places, like black holes or as it was the big bang, in which laws micro and macro living. But when you combine the equations that explain the four forces to understand what happens in a black hole (or the big bang) results are absurd and impossible. This is what is called a "singularity." Therefore, both theories fail and we must find a new one which can explain the four fundamental forces together.
A unifying theory
string Proponents say they have come up with a theory that explains the four forces together and whose equations do not give absurd results. Although this theory is controversial among physicists, there is consensus that it is "beautiful" and that its fundamental principles are simple.
When physicists speak of beauty, are not as subjective as when you think about a picture, but the emotions they experience in front of the scientific beauty are very similar to those experienced in front of the beauty of art.
means that, at least, has two essential characteristics:
1. Presents a unifying symmetry.
2. Has capacity explain a large number of phenomena with a few principles, or economic mathematical expressions.
A paradigmatic example of beauty in physics is the world's most famous equation: e = mc 2. With this equation of special relativity, Einstein explains the equivalence (symmetry) between energy and matter in an extremely simple. Who is not accustomed to dealing with scientific equations may not perceive this beauty at first sight. To help, simply saying that while Einstein's equation occupies a small fraction of line, there are equations that occupy entire books.
Einstein equation meets the two characteristics of beauty in a theory because it unifies matter and energy as manifestations of the same phenomenon.
The theoretical beauty of string theory comes from the hand of an own resource of science fiction: the extra dimensions . By adding more dimensions than those we know, the calculations make it possible to explain the four fundamental forces as if they were one.
In short, the theory states that everything in the universe is formed by infinitesimally small vibrating strings. So small, that if we expand an atom the size of our solar system, the string would be great as a tree.
ropes, a hundred trillion times smaller than a proton, are vibrating. Each mode of vibration represents a different particle. According to this model, every subatomic particle corresponds to a different resonance that vibrates only at a characteristic frequency.
Each mode of vibration corresponds to a different particle.
(Source: smartplanet)
Where does the vibration of the strings? To find the answer, think of a boy playing on the beach with some molds to shape the sand castle, sea stars, strollers ... Just as the sand takes different forms to be in contact with these molds, the strings take on different vibrations due to contact with the other dimensions.
The vibration of the strings depends on their contact
with the other dimensions. (Source: smartplanet)
From the 60's until today, string theory has gone through several stages. Today, more elaborate version the string theory called M theory , says there are 11 dimensions. However, earlier versions of the theory have argued that the dimensions were 10, in one case and 26 in another.
These numbers come from some mathematical calculations that determine how many dimensions are necessary for the strings vibrate in a way that forces are fully explained. With the precise number of dimensions, the four fundamental forces fit like a puzzle and singularities or impossible results that arise by combining relativity and quantum mechanics disappear.
SF Properties
String theory is attractive not only because, if true, could be the masterpiece of physics. By studying its possibilities are speculations that lead to science beyond the imagination of fiction writers.
Many of these speculations have to do with travel through the universe and time. One of the most striking ideas is what is called "wormholes" and arises from the possibility of more dimensions.
(Source: smartplanet)
Between the Earth and the star Alpha Centauri is 4.3 light years. Because you can not travel faster than light, at least it would take to make that trip would be 4.3 years.
But spacetime is curved, if we could open a wormhole between Earth and Alpha Centauri, would arrive in less time. It's the same system used in the film Jodie Foster "Contact" to travel the universe.
However, to open a wormhole in spacetime, we have to use a lot of energy so high that is unattainable for a civilization like ours. To get an idea, we need a greater amount of energy that the sun can produce over a lifetime. And that is something that probably will not reach in less than thousands of years.
Advanced String
In the mid 90's, string theory was not a good time. At that time, there were five different versions of the theory that sought to give a unified explanation of physical phenomena, which was paradoxical.
Edward Witten, whom many consider today as the successor to Einstein, made a revolutionary theory that solved the paradox of the five theories. From their point of view, there were five different theories but five approaches to the same concept. This is what is called "M theory ."
Witten, Einstein considered the successor of
According Witten, "M" stands for mystery, magic or matrix, according to individual taste ( www.sns.ias. edu / ~ witten / papers / mmm.pdf ). But probably the M comes from "membrane" few objects larger than the strings, a kind of surface.
Before Witten theory String felt there were ten dimensions. But the theory M added one more. This dimension is what allows the strings are stretched to form membranes.
Unlike the strings that are two-dimensional membranes could have three or more dimensions and to have enough energy, one could reach a gigantic size , may be as large as our universe. This is what is called a "brane". Branas
or parallel universes
The concept of "brane" is revolutionary because it allows a surprising possibility: our universe could be contained within a membrane that could abut other branes. As the slices of bread (branes) are one bread, all the branes would be contained in a much greater than what physicists call "bulk" thickness. The other branes (sliced \u200b\u200bbread) would, in fact, parallel universes.
Each membrane, or universe, would be contained in the bulk.
(Source: smartplanet)
Our universe would not only be unique and special, but one of many variants. The constants of physics could be different in other universes and then also have different physical laws. In a perhaps the matter could not be formed, in others it would be diluted ...
These universes exist in the extra dimensions of M theory, dimensions that surround us. Some people come to make sure they are on our side, less than a millimeter away. But if that's true, why we can not see or touch?
If our atoms and particles are confined to our brane, though there is a brane in another dimension of space, we could not touch it precisely because our atoms and particles can not leave our brane. If this concept is true, it could help solve one of the great mysteries of modern science: gravity.
gravity through the worlds
Gravity is much weaker than the other forces, specifically, 10 38 times (one followed by 38 zeros) weaker than electromagnetism. This has caused much confusion among scientists but the new string theory can throw new light on the problem.
In fact, the gravity would be as strong as the other fundamental forces although some why we can not perceive. Could it be that gravity is "diluted" among all the membranes and is the only one of the four forces that pervades them all.
While the full force of electromagnetism is contained in our brane, gravity abandons making it appear that their strength is lower than it is. Thus, only perceive the force of gravity corresponding to our brane.
gravity Why be so different from other forces? M theory says the answer lies in the way of the strings. For years, always thought of the closed strings and bands. But the theory M, it is believed that everything around us, matter and light, consists of open strings. The ends of each of these strings would be subject to our three-dimensional brane.
cerrdas Strings (brown) and string
open (blue). (Source: smartplanet)
But there would also closed strings and one of its varieties would be responsible for the particle of gravity: the graviton. As a closed, has no fixed end in our brane and therefore is free to escape to other branes. Thus, its strength is diluted and seems weaker than the other tres fuerzas.
Esto sugiere una posibilidad intrigante. Como estamos “ciegos” a las otras branas porque nuestros átomos y partículas no pueden escapar, podríamos llegar a saber algo de esas otras branas por medio de la gravedad.
Antes del big bang
No sabemos si los universos paralelos pueden influir sobre nosotros, pero el concepto de branas ha dado lugar a una idea muy polémica. Hay quienes afirman que los universos paralelos han desempeñado un papel esencial en nuestra historia, de hecho, los responsabilizan de nuestra existencia.
El concepto de las branas paralelas que se mueven en dimensiones adicionales podría change the course of cosmology. Some scientists theorize that the mystery of the origin of the big bang could be on the movement of these parallel branes. At some point, they might bump into each other and the enormous energy of that collision would be what gave rise to the big bang.
parallel Branas
collide and form a big bang.
In fact, it is believed that these shocks may have been given many times in the past from recurring again in the future. Although revolutionary, this theory still has a series of mathematical inconsistencies hampering its acceptance.
Controversy experimentation
The same problem that scientists have to open a wormhole, you have to devise an experiment to demonstrate the validity of string theory. While the theory is convincing, can not be demonstrate empirically the amount of energy required for a string.
But even though we can not see the strings, maybe we can see their footprints . If the strings were in the early universe when everything was so small, it is more likely to leave marks or traces on their environment and then when everything is expanded, those footprints would have been enlarged as everything else.
There are also ways to check if the theory is well under way. One of them is to find a graviton in a particle accelerator. Could do only two accelerators: Fermilab in the U.S. and Large Hadron Collider (LHC) at CERN ( www.cern.ch ) is building in Switzerland. The LHC will start operating in 2007 and will be seven times more powerful than Fermilab.
As provided by M-theory, the graviton escape to another dimension and the greatest achievement would be to obtain an image of the graviton at the time of the leak.
A hypothetical graviton at the time of the leak.
(Source: Fermilab)
Another of the top priorities of both laboratories is to find a property described by string theory called "supersymmetry." The theory predicts is that all subatomic particles must have a much heavier equivalent is called "particle s" or "sparticles."
The discovery of supersymmetry would be a major endorsement
for string theory. (Source: smartplanet)
So far, nobody has seen for supersymmetric particles, being heavier than their partners, require more energy to produce a collision that makes them visible. It is expected that the LHC has enough energy as to make them detectable.
Even if you find the graviton to escape to another dimension and it was shown that supersymmetry exists, it does not prove that the theory is correct. However, be very strong evidence that the theory is well under way.
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