At the borders of the imaginable: the ultimate theory of the universe?

The elegant universe / Brian Greene
In this book of 600 pages exciting from beginning to end, Brian Greene explains with simple words and examples of many scientific theories including relativity. Maxwell and Einstein will overshadow Newton over the new discoveries. This book is accessible to all those who want the secrets of the universe are revealed them. It is not easy to make a comment without defining the substance, the title is not necessarily explicit.
First, the author explains why the theory of general relativity of Einstein is antagonistic to the quantum theory of Planck as if trying to amalgamate these two theories, one leads to aberrations. And if a new theory managed to make the connection between the two? This is where the theory of vibrating strings outcome of Veneziano's work in seventy. Years (bosonic string theory)
Before addressing this point, the author describes the interactive properties of the speed of light, space and time .And we will have to go further to get the idea that the spatial speed an object is just the way his journey in time is diverted. The true nature of space and time we are hidden by the slowness of our movements on a cosmic scale.
Newton began gravity equation but was unable to say what it actually was. The theory of general relativity, which states that the speed of light is an absolute limit then knocked to the fact that the gravitational force acts instantaneously in proportion to the mass of bodies in the presence and in inverse proportion to the square of the distance between them . Dilemma?
We'll have to get used to the idea that space reacts to the mere presence of an object with a mass deforming. John Wheeler explains that "the mass exerts its influence on the space by dictating its curvature; space exerts its grip on the mass by dictating its movement. "It was he, after the work of Schwarzschild black holes that dénomma stars so dense that light can not escape.
Greene then speaks of light and the particle nature demonstrated in the photoelectric effect, as well as its wave nature demonstrated in experience-slit. But in the world of every day, the enormous value of c (speed of light) veil the true nature of space and time, the smallness of the constant Planck obscuring the wave nature of matter. And the work of Max Born followed by those of Niels Bohr tells us that the electron revolves around the nucleus is only a probability wave !! Very strange and disturbing! Not really because the macroscopic level, these phenomena do not play unlike what happens at the microscopic level. Also exciting the work of Feynman that ultimately explains that although the quantum theory gives us an absurd description of the nature, it is in perfect agreement with all experiments performed. The Heisenberg uncertainty relations will obviously add to the disorder of the situation: a more accurate measurement of the position of the electron necessarily implies greater inaccuracy in the measurement of speed and vice versa. While Einstein was not quite agree with his colleagues, the work of John Bell and Alain Aspect showed that Einstein was wrong and that nature is such that Heisenberg described it.
With so many inconsistencies and incompatibilities, string theory came to bring some unity. The work of Michael Green and John Schwarz and Joel Scherk helped to fundamentally change the theoretical description of ultra-microscopic properties of the universe, and the conflict between quantum theory and general relativity through small dimensional vibrating strings of a length close to the Planck length (10 to the minus 33 centimeters !!!) modeling the elementary particles. Moreover this new quantum theory to include gravitation. The masses and expenses resulting from the precise way in which vibrating strings whose tension is colossal, 10 power 39 tons !! (Planck Voltage)
This new theory initially was criticized and often ignored. This required Schwarz and Green until 1984 to see their work recognized. The first superstring revolution intervened in 1986, the second in 1995 with Edward Witten to try to develop equations for structuring this beautiful theory. The big question for researchers is whether this theory really is ultimate!
We must not forget that the order and consistency of the nature of mechanisms are organized within the principle of symmetry (rotational and gauge) of the Universe. Scherck and Schwarz showed that quantum string theory included vibrating strings that had zero mass configuration and characteristics of the spin 2 graviton. From these two ideas, the author addresses the complex notion of supersymmetry, "which can be associated with a change in perspective in a quantum extension of space and time." The implications of this theory are then developed and prove capitals about the unifying concept. The superstring theory follows that Gliozzi, Scherk and Olive devised, and Wess and Zumino peaufinèrent by naming "supersymmetric quantum field theory" by applying it to fields of point particles.
Then Greene describes with great dexterity and ease the work of Kaluza (1919) and Klein (1926) relating to hidden dimensions. Merely to imagine that at least a further dimension to our universe led Kaluza to meet in his new equations the theory of gravity and Einstein's theory of electromagnetism Maxwell. But it took forty years for his work to be recognized and taken up and developed. In 1984 string theory proved to be the missing applicant alone nine or ten spatial dimensions and one temporal. These extra dimensions would be twisted into a Calabi-Yau space which remains to determine the exact conformation.
Greene made us realize little by little that this beautiful string theory, and if so ambitious aesthetic fishing in experimental signatures. We do not yet know well the user manual and current investigations in search of these signatures require an amazing technological breakthrough to study matter at the Planck scale. It will be rather through indirect observations of experimental data will be obtained in the coming years.
In the fourth part, Greene discusses the structure of space-time and the concept of quantum geometry forced to give up the Riemann geometry that proves to be true and large scales. At the Planck length, it must abandon its Gauss and Riemann predecessors, Lobachevsky and Bolyai. This part is quite difficult for the layman admittedly because by addressing subplanckiennes distances, it is bathed in complete abstraction. Nevertheless, the work of Greene and Plesser confirmed Candelas lead to the discovery of mirror symmetry of string theory that provides an effective tool for understanding both the physics of string theory and mathematical spaces Calabi-Yau. Greene and evoke the flop transition and possible tearing of the structure of spacetime.
"String theory provides a unifying framework and to physical and could help to forge a union within mathematics itself. "(Greene)
In the following chapter, the author addresses the question of the inevitability that our universe is as it is. The universe could it be different or not? To see!
Results from the second superstring revolution have shown that in fact the five string theories are part of a single unified framework called "M-theory". Through the "perturbation theory" and a resulting disturbance approach, understanding of string theory has been refined.
The application of string theory to understanding the structure of black holes is still in its infancy. The singularity of space-time from the center of black holes and the question of the loss of information when crossing the horizon remain unexplained for now. Then raised the question of space 'time between the Big Bang and the Planck time (10 to the minus 43 seconds). If we apply the equations of general relativity to this region, we get that the Universe is becoming ever smaller, hotter and denser. At time zero, the Universe size is zero, the temperature and density tend to infinity: the standard theoretical Big Bang model is collapsing. It was then that string theory will fly to the rescue of general relativity and quantum theory. And speaking of string cosmology: it is still at the very début'mais with encouraging results that save the standard theory. The idea of ​​symmetry breaking the Planck time Brandenberger and Vafa invoked by is particularly interesting.
In conclusion, "cosmology exerts a deep fascination on us: by understanding the how the beginning of everything we hope to approach the why. "To excite our curiosity, the author talks about the multiunivers Linde and the anthropic principle. And finally, the strings of string theory they would not be the strands of spacetime in a state of coherence? Before these strings it begin to vibrate coherently, would they not been an inconsistent state would have existed no time or space?
Leibniz said, "Why something rather than nothing? "The new formalism derived from string theory may one day long ago tell us why. But as Einstein said, is it certain that we can explain everything?
A fundamental work relatively easy to read even if it does not explain everything.