Friday, September 28, 2012

The Universe and its beginnings


The theory of general relativity already contains and explains the possibility of a finite and unlimited universe, that possibility pretends to be a discovering and development from the quantum mechanics, it is proposed as a possibility that can only be generated from the theory of the quantum gravity, however the general theory of relativity already proposes it but by being proposed by Einstein together with the hypothesis that the radius of the universe would be independent of time, it was completely discarded with the discovering of an expanding universe.

This idea is not quite right because the solutions of Friedman of an expanding universe do not (in any way) exclude the idea of a universe finite but unlimited, this is it does not imply that the universe should be infinite or with a limit or singularity completely defined.

Given that the idea of a finite and unlimited universe contains without any trouble the ability of this to be under expansion. However the idea of a finite and unlimited universe under expansion seems to be not comprehended completely, as well as its considerations about the beginning of the same.

In fact a finite and expanding universe leads inevitably to a initial state where the distances in between anything would be null, this is in a concept similar to the Bing-Bang; in the other hand an infinite universe would prevent this inevitable consequence because there would be no center on which the whole universe could concentrate in, because any point could be considered the “center” inside a infinite universe; however it is necessary to comprehend that an infinite universe should be infinite since the beginning of the “time” because in any other way it would have to be finite without any possibility of mistake; it is not the same an infinite quantity and a quantity that reaches the infinite, this is that the universe could be expanding and had started with a finite magnitude means that it is still finite and would become infinite only if it keeps expanding during a interval of time infinite.

Because of this, an infinite universe would exist since ever or would be there forever. In the other hand a finite universe expanding would have consequently a point in time that could be called the “beginning of time” whatever that would mean. Under these perspectives we can divide the possible models of the universe in the following way:

A) An infinite universe which by definition is unlimited, because as much as you travel the universe in one given direction there always be more universe to travel, this does not imply in any way that it would be possible to return to the starting point because as it can be observed, an infinite universe has no limits or singularities which will define the frontier of the universe. Also an infinite universe (even under expansion) should be infinite at any given time, and by which there's no place for a singularity such as the Big-Bang to generate it, the infinite universe is infinite independent of the time. In this way the concept of “universe under expansion” is not well defined as the universe is infinite since ever and forever.

B) In other way, a finite universe can be limited or unlimited, if it is unlimited it implies that there is not frontier or singularity on which the universe ends, in this case the expansion means that at the beginning this could be collapsed into a point of length zero; and it was created indeed in a singularity such as the Big-Bang, and could end in a Big-Crunch, given that being finite in extension, exists therefore a center to collapse; or perhaps it could keep expanding forever, reaching an infinite extension at the end of time.

C) The last case implies a finite and unlimited universe; this case if it were not expanding it will illustrate the primary model (defined by Einstein), where obviously there is no place for a singularity, such as the Big-Bang because in fact, the universe is static; this is it is not expanding. However, in the case of a finite and unlimited universe that is expanding the panorama changes radically; because necessarily it begins in a singularity such as the Big-Bang where unavoidably the universe hast a null magnitude.
Now, before explaining why this is the case, first we should account that the universe, either will continue expanding forever or finally it will collapse around itself in a Big-Crunch; going back to the beginning of the universe in a singularity, let's assume a tri-dimentional universe (this is, two spatial coordinated and one temporal coordinate) which is finite and unlimited, meaning, the universe is formed exclusively by the surface of a ellipse (or a sphere as well, however the ellipse generalizes the model, because it does not pre-establishes the perfection of the shape of a sphere), because obviously it has two spatial coordinates; in this case the expansion of the universe is given by the increase of the radius of the sphere that “contains” our universe, as you can clearly see this means that the expansion should have started with a radius of null size, which in consequence will yield a null surface; meaning, a state where the universe collapsed around itself in a null space; this describes clearly the image of the Big-Bang; if we translate the analogy to a quadric-dimensional the consequences are the same.
As you can see this theory does not completely clarify the initial state of the universe, the difficulties are still there.

In another way, the ideas of a universe in contraction remembering the future; are equally unnecessary and absurd; because in any case for a person in this state; simply their “past” will be what we know their “future” and vice versa; this would imply in the case of a universe that at any moment it would stop expanding, that in the precise moment where the universe stops its expansion to start its compression there should exist a singularity in which “time” would stop to start its backwards flow; this is absurd, it would imply that truly the universe will return to its initial state from that point on.

However, the previous problem is defined by thermodynamic questions related to the entropy, these complications can be eliminated if we conceive a closed cyclical universe; this is, in the initial state totally chaotic and unordered of the universe, it emerges in an instant of time a state of “apparent order” (meaning an ordered state just as we perceive it); which favors and starts the evolution of the universe of which we are part of; of course at that instant we could identify that the disorder or entropy of the universe, not really being null, it is in a minimal state; through the evolution process of the universe the entropy of the universe starts to increase through the destruction of stars, primitive planets, etc.; which gives birth to galaxies and new systems, and of course to us, obviously we keep contributing more entropy to the universe.

The universe keeps its expansion and after all with a natural transition it starts its contraction; its entropy keeps growing, until the unavoidable happens; the collapse of the universe in the Big-Crunch, of course in this state planets are so close to each other that the start to collide between each other, generating their destruction and augmenting the entropy, stars explode, finally the universe collapses disintegrating matter as we know it and augmenting the chaos; there is a time where chaos is total, there is a state where only elemental particles coexist; from this state of chaos, which we don't know how long it will last; it will be generated at any moment a state of “apparent order” and the cycle will start again.

This model that could be supported by quantum mechanics developed under the premises of the general relativity and its definition of the relativity fields; would be also naturally supported by the unified theory.

It is my opinion that there is no sufficient empirical knowledge that prevents supporting quantum mechanics through the general relativity theory; contrarily it everything seems to signal that this is possible; even generating conclusions about the origin of the universe.


First draft originally written in Spanish during Feb 2006

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