Why is the Universe Isotropic? The theorem of Collins and Hawking which states that only a subclass of measure zero of the space of homogeneous solutions approach isotropy and the alternative approaches that postulated, according to the second law of thermodynamics, that the universe began in a highly regular state, i.e.: With the dominant energy condition and the criterion of positive pressure, and the conditions of the equations of matter described by GR and QM, the homogeneous initial data set leads to models that approximate isotropy its measure is zero in the set of all homogeneous initial data. Explanation: - Conditions on the matter and their behavior are established. These conditions can be translated into essentially the energy / matter and generate attractive gravity fields interact with each other and with gravity under the laws described by general relativity (GR) and quantum mechanics QM). - All possible initial homogeneous conditions of the universe are chosen and that conforms a space (analogous to the real line, see picture, but with more dimensions and more amorphous). Among all of them, we study the leading ones to the isotropic universes like ours when its cosmological evolution unfolds. Recall that consistency does not necessarily imply isotropy. - The conclusion of the theorem is that the subspace of homogeneous initial conditions that give rise to isotropic universes upon its evolution the measure is zero, ie, the probability that our universe exists is NULL. Result: If our universe begins in a arbitrary initial conditions, the probability to start with some of them to ensure that they will develop an isotropic universe is zero. The result of this theorem is that we are living in a universe that is impossible its existence. But still exists, Galileo would murmur to this court. Yes, the universe exists even when this theorem tells us that is not possible. In this situation, since the universe is there around us and we can not deny its existence and properties have to find a way to explain this fact. In the article by Collins and Hawking, linked below, opt for a solution of the Multiverse. Infinite universes were created, each with initial conditions and we are in this because we are here and so we describe it well. Others may argue that a superior being, a demiurge, a god, has selected the conditions of the universe so that being as they are. However, the physics gives us the solution in an elegant and simple way, just as Einstein said, there are more believers than thinkers because it is easier to believe than to think. The solution to this puzzle comes from the hand of inflation theory, which postulates a massive expansion of the universe in a tiny fraction of time shortly after its origin. This process was able to enlarge the size regions from proton scale to cosmic proportions. The explanation for the isotropy and homogeneity is immediate. The universe may begin in the conditions you want, were seeing a tiny original universe went through an inflationary process serving. However, if very anisotropic and heterogeneous the whole universe was at its inception, in very small regions always have a high proportion of isotropy and homogeneity, with tiny variations, if that region is enlarged wildly, then it will find an isotropic space. Simple, elegant and natural. All observational data in cosmology suggest that inflation occurred, we need to know the details, but the qualitative picture we have very well defined. And of course, inflation provides a solution to this theorem and cosmological phenomenon that energy / matter did not behave in the manner described in the explanation of the theorem, but had a component that generated no expansion and attraction, prompting inflationary expansion, called the inflaton, the Higgs field that produced inflation. In addition, the inflationary model predicts the generation of small irregularities in the isotropy and homogeneity of the early universe and allows us to calculate its evolution. Just predict the fluctuations seen in the cosmic microwave background (CMB for short) and their distribution, fluctuations that are the footprints of the seeds of the large-scale structure of the universe, which are tiny, about one part of 100,000 related to an average temperature of -270.15 degrees Celsius, about three degrees warmer than absolute zero. articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1973ApJ...180..317C&defaultprint=YES&filetype=.pdf
Posted on: Tue, 12 Aug 2014 18:26:44 +0000
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