However, they have had considerable difficulty explaining why different regions of the universe have nearly the same temperature and other physical properties. This is a problem because information can only be exchanged at the speed of light and the Big Bang model indicates the separation between different regions of space would have been too large to allow enough time for information to be exchanged between them.  Therefore, because they evolved independently from each other they should have different properties.  This inconsistency between theory and observations is what cosmologists call the Horizon Problem.
In 1980 Alan Guth, Andrei Linde, Paul Steinhardt, and Andy Albrecht proposed a modification to the big bang theory which appeared to provide a solution by postulating a short 10 ^{− 32} second period of exponential expansion (dubbed “inflation”) within the first minute or so of the universe’s existence.  During inflation, the universe would have increased in size by an enormous factor.

If correct, inflation solves the horizon problem by suggesting that prior to the inflationary period the entire universe was extremely small and therefore each point was causally connected.  It was during this period, according to its proponents the physical properties of the universe evened out.  Inflation then caused its volume to increase to the point where different parts were too far apart to allow their properties to interact.  This essentially froze any irregularities and prevented them from being “smoothed out” which according to this theoretical model explains why the universe appears to be almost, but not perfectly homogeneous.  In other words they assume the solution to the horizon problem is the fact that in the modern era distant areas in the sky appear to be unconnected causally, but they were in the past because they were much closer together.

However, there is no observational basis for defining what caused this rapid inflation to begin or end.  Therefore, some say it is an “ADHOC” or contrived explanation of a flaw in original the Big Bang Theory.

Another problem with the inflationary concept is made evident by the fact that our universe is not homogenous because observations tell us it contains large-scale structures such as galactic clusters. 

This presents another problem for its proponents because, as mentioned earlier the reason Alan Guth proposed it was to explain why the universe was homogeneous.

This is why they had to add the passage “This essentially froze any irregularities and prevented them from being “smoothed out” ” to its description to “force” it to agree with the observation that it is not.

The only problem with this is that they have been unable to define what caused these initial irregularities to occur.

Some have theorized that quantum fluctuations or a temporary change in the amount of energy in space, arising from Werner Heisenberg’s uncertainty principle may be responsible.  But here again there is no observational evidence to support this claim.

In other words an “ADHOC” theory was created to explain why the universe is homogeneous must be modified by another “ADHOC” or abstract theoretical construct to explain why it is not.  (ADHOC in the sense that neither have a foundation in experimental or observational science.)

Physics as the name implies is the science that deals with physical properties matter, energy, motion, and force. Therefore the primary vehicle to guide our understanding of our universe should be the “reality” of the observable properties of matter energy, motion and force to develop theories of its origin and not the unobservable properties of an inflation field.

For example observations tell us our universe is expanding.

As mentioned earlier proponents of the Big bang explain this by assuming the energy driving its expansion was created in a tremendously hot dense environment.  Yet they are unable to tell us where the energy came from to create that environment.  Therefore they must assume that it was created out nothing which would be a violation of the law of conservation of energy/mass.

However, there is another explanation for the origin of our expanding universe which is not, as was shown in the article “The Return of the Big Bang” Jan. 15, 2008 based on the unobservable properties of an inflation field , does not violate any of the accepted physical laws of physics, and can be derived from direct observations of our environment.

We know from observations the equation E=mc^2 defines the equivalence between mass and energy in an environment and since mass is associated with the attractive properties of gravity it also tells us, because of this equivalence, the kinetic energy associated with the universeâ€s expansion also possess those attractive properties.  However the law of conservation of energy/mass tells us that in a closed system the creation of kinetic energy cannot exceed the gravitational energy associated with the total energy/mass in the universe and that a reduction in one must be compensated for by an increase in the other

Therefore the total gravitation potential of the universe must increase as it expands and cools approaching a maximum value at absolute “0” while at the same time the kinetic energy of its expansive components must decrease.  Therefore, at some point in time, the universe it will enter a contractive phase because the total gravitational potential must eventually exceed the kinetic energy of its expansion.  This is would be true even though the gravitational potential of its Kinetic energy components would be disturbed or “diluted” by a factor of c^2.

(Many physicists would disagree because recent observations suggest that a force called Dark energy is causing the expansion of the universe accelerate. Therefore they believe that its expansion will continue forever.  However, as was shown in the article “Dark Energy and the evolution of the universe” Oct. 1, 2012 if one assumes the law of conservation of mass/energy is valid, as we have done here than the gravitational contractive properties of its mass equivalent will eventually have to exceed its expansive energy because as mentioned earlier kinetic energy also possess gravitational potential therefore there will be constant force opposing this accelerated expansion. Therefore the gravitational potential of Dark Energy must slow the rate of the acceleration and eventually allow gravity to take over and cause the universe to enter a contractive phase.  There can be no other conclusion if one accepts the validity of the laws of thermodynamics and Einstein General Theory of Relativity.)

The rate of contraction will increase until the momentum of the galaxies, planets, components of the universe equals the radiation pressure generated by the heat of that contraction.

At some point in time the total kinetic energy of the universe would be equal to the total mass equivalent of that energy or E=mc^2, where “E” equals the total Kinetic energy content of the universe and “m” equals the total mass content of the universe.  From this point on the velocity of the contraction will slow due to the radiation pressure generated by the heat of its contraction and be maintained by the momentum associated with the remaining mass component of the universe.

However, after a certain point in time the radiation pressure generated by it will become great enough to ionize its mass component and to cause it to reexpand.

Yet at some point in future the contraction phase will begin again because as mentioned earlier its kinetic energy cannot exceed the gravitational energy associated with its mass/energy equivalent.

Since the universe is a closed system, the amplitude of the expansions and contractions will remain constant because the law of conservation of mass/energy dictates that in a closed system it remains constant.

This results in the universe experiencing in a never-ending cycle of expansions and contractions of equal magnitudes.

This would solve the horizon problem because the repeated cycles would allow different regions of the universe to mix and equalize thereby explaining why their temperature and other physical properties are almost identical.

This would be analogous to mixing the content of two cans of paint by pouring one into the other.  The evenness of the mixture would increase in proportion to the number of times one pored one can into the other.

Similarly the evenness of the temperature distribution and physical properties of the universe would increase in proportion to the number of cycles it had gone through.

However it also explains why there are small temperature and other physical irregularities in the large-scale structure of the universe.

One cannot completely mix two different colors of paint no matter how many times they pour one can into another because the random motion of the different colored paint molecules means that some regions will have more of one color that the other.

Similarly the random motion of the baryonic matter in the universe means that some regions will have more matter or be denser that others no matter how many cycles of expansion or contraction it has undergone.

This explains why the large-scale structures such as galactic clusters exist.

Many cosmologists do not accept the cyclical scenario of expansion and contractions because they believe a collapsing universe would end in the formation of a singularity similar to the ones found in a black hole and therefore, it could not re-expand.

However, according to the first law of thermodynamic the universe would have to begin expanding before it reached a singularity because that law states that energy in an isolated system can neither be created nor destroyed

Therefore, because the universe is by definition an isolated system; the energy generated by its gravitational collapse cannot be radiated to another volume but must remain within it.  This means the radiation pressure exerted by its collapse must eventually exceed momentum of its contraction and the universe would have to enter an expansion phase.  The mass/energy of the universe will oscillate around a point in space because its momentum will carry it beyond the equilibrium point were the radiation pressure was equal to its gravitational contractive component. 

This would be analogous to the how momentum of a mass on a spring causes it spring to stretch beyond its equilibrium point resulting it osculating around it. 

There can be no other interoperation if one assumes the validity of the first law of thermodynamics which states that the total energy of the universe is defined by the mass and the momentum of its components.  Therefore, when one decreases the other must increase which means the universe must oscillate around a point in three-dimensional space.

The reason a singularity can form in black hole is because it is not an isolate system therefore the thermal radiation associated with its collapse can be radiated into the surrounding space.  Therefore, its collapse can continue because momentum of its mass can exceed the radiation pressure cause by its collapse in the volume surrounding a black hole.

As mentioned earlier the heat generated by the collapse of the universe would raise the temperature to a point where electrons would be strip off all matter and it would become ionized, making it opaque to radiation.  It would remain that way until it entered the expansion phase and cooled enough to allow matter to recapture and hold on to them.  This Age of Recombination, as cosmologists like to call it is when the Cosmic Background Radiation was emitted.

One could quantify this scenario by using the first law of thermodynamics to calculate the how long it would take for the radiation pressure generated by the gravitational collapse of the universe to become large enough to cause it to expand and determine if it would allow enough time for different regions to be causally connected to the point where it could explain Horizon Problem and why there are small variations homogeneous structure.  Additionally one could determine if the heat generate by that collapse would be great enough to ionize its mass component enough to explain the properties of the cosmic background radiation. 

It should be noted that this derivation of the universe’s origin, its temperature and matter distribution does provide an observational method for verification or falsification because it relies exclusively the accepted laws of physics and on interoperation of physical observations and not as is the case with the inflation model on abstract creations of human intellect.

Later Jeff

Copyright Jeffrey O’Callaghan 2011

The post A sensible solution to the Horizon Problem appeared first on Unifying Quantum and Relativistic Theories.

One is it that it allows one to understand why the universe must be flat in terms of our everyday experiences.

Einstein gave us this ability when he used the velocity of light to define the geometric properties of space-time because it allows one to convert a unit of time associated with energy in his four dimensional space-time universe to a unit of a space identical to those of our three-dimensional space.  Additionally because the velocity of light is constant it is possible to defined a universe made up of four *spatial* dimensions that makes predictions identical to those he had attributed to four dimensional space-time

For example a four dimensional space-time universe or one made up of only four *spatial* dimension can be geometrically open, closed, or “flat” and its shape is dependent on the quantity mass and energy within it.
In an opened universe, there is insufficient matter to halt the expansion initiated by the big bang.  This will result in a saddle shape or open universe, which will continue to expand forever.

In a closed universe, the gravitational potential of its mass is large enough to overcome the expansive forces of the big bang.  This will result in the universe having a spherical shape, which would be destined to collapse.

A universe will be flat if the attractive gravitational potential of matter just equals the expansive energy of the big bang.  This will result in the expansion slowing and only stop after an infinite amount of time has passed.

However, a recent observation by NASA’s WMAP satellite has shown the universe is flat to within a 2% margin of error.

But why the universe appears to be flat even after 14 billion years of expansion is still a mystery because a flat universe is like the top of a hill.  If you are a little away from it – a bit open or a bit closed – the expansion of the universe soon drives you far away from this value, just as a ball that is a short distance from a hilltop will roll down to the bottom.  Therefore, when the Universe was one second old, it must have deviated from flatness by less than one part in ten-thousand-trillion (10¹⁶).  This is a problem because it is hard to understand how the amount of mass and the energy associated with the expansion could have been adjusted to such precision.

To resolve this issue physicist Alan Guth proposed the universe underwent a very rapid period of expansion increasing its size by more than a trillion in the first few nano-seconds after its birth.  This resolves the flatness problem because its size is magnified by the inflation factor so much that locally it appears flat.

The reason for this can be understood by imagining what a two-dimensional creature who was living on a surface of a balloon would observe regarding the curvature of its surface.  If the size of the balloon were small compared to his field of vision he would notice that it surface was curved.  However, if its size was very large compared to his field of vision it would appear to him to be flat.

Inflation solves the flatness problem because it predicts the size of the universe increased so much in the initial expansion that the portion we can observe appears to flat.

However, another reason why the universe appears to be flat is because if the universe is a closed system, the first law of thermodynamics tells us the sum of the gravitational potential of its energy/mass and its kinetic or thermal energy is constant.

As was mentioned earlier Einstein’s genius allow us to defined a universe made up of four *spatial* dimensions that makes predictions identical to those he had attributed to one made up four dimensional space-time.

Therefore instead of deriving kinetic and gravitational energy in terms of unidirectional curvature or depression in a “surface” of a space-time manifold one can as was done in the in the article  “Defining potential and kinetic energy?” Nov. 26, 2007 one can derive both in terms of oppositely directed curvatures in “surface” of a three-dimensional space manifold with respect to a fourth *spatial* dimension.  In other words if one defines gravity in terms of a depression in its “surface” one can derive kinetic energy as an in terms of elevation in it.

This differs from Einstein’s theoretical definition of energy in that he defines both gravitational and kinetic in terms of in terms of a unidirectional displacement in a four dimensional space-time manifold.

However, unlike Einstein’s definition: defining gravity and kinetic energy in terms of oppositely directed curvatures in space is not based entirely on theory because observations tell us that kinetic energy is oppositely directed from gravitational energy.  For example, the kinetic energy of an orbiting satellite is oppositely directed from its gravitational energy.

This difference is significant to our understanding of the shape or flatness of our universe because as mentioned earlier its curvature is related to the ratio of total gravitational potential of its energy/mass to the total kinetic energy of its expansion.

This is because the universe is a closed system with respect to its energy/mass the first law of thermodynamics tells us there must exist a 1 to 1 correspondence between the gravitational potential of the universeâ€s energy/mass and the oppositely directed kinetic energy associated with its expansion because all of its expansive energy must originate from within its energy/mass.  This 1 to 1 ratio between gravitational potential and kinetic energy will be maintained throughout the entire history of the universe because kinetic energy also posse gravitational potential that is equivalent to its energy content. 

However, as was shown in the article “Defining potential and kinetic energy?” this means there must be a 1 to 1 correspondence between the downward directed curvature associated with its gravitational potential and the upward directed one associated with its Kinetic energy.  Therefore, on a large scale the universe will appear to be flat because these oppositely directed curvatures will cancel each other.

This means one does not have to assume the universe underwent an inflationary period to explain why it is flat now and has remained that way if one assumes as is done here that the gravitational energy of energy/mass and its kinetic energy are related to oppositely directed curvatures in a “surface” of a three-dimensional space manifold with respect to a fourth *spatial* dimension.

This cannot be done in terms of four-dimensional space-time because time or a space-time dimension is observed to move only in one direction forward and therefore could not support the bi-directional movement required to define the asymmetry between gravitational potential and kinetic energy.

This concept of a zero energy universe may sound strange to many, but it is rather simple to understand.  A ball thrown up in the air has two forms of energy: kinetic and gravitational potential.  If kinetic energy were considered as positive, the potential energy, due to the gravitational pull of the Earth, would be negative.  If the positive portion of the energy beats the negative portion, the ball will escape from Earth.  If the negative energy is greater, it will return.  If the total energy is precisely zero the ball will barely escape – slowing to a stop when it is infinitely far away.

Another way of understanding this concept compare it to the effect crumpling a piece of paper has on its overall flatness. 

Our experiences with a  piece of paper shows us that if one crumples one that was original flat and views its entire surface the overall magnitude of the displacement caused by that crumpling would be zero because the height of it above its surface would be offset by an oppositely directed one below its surface.  Therefore, if one views its overall surface only with respect to its height its curvature would appear to be flat.

Similarly, if the gravitational potential of the universe’s energy/mass is oppositely directed form that of its kinetic energy the “surface” of a three-dimensional space manifold with respect to a fourth *spatial* dimension would appear to be flat because, similar to a crumpled piece of paper the “depth” of the displacement below its “surface” caused by it would offset by the “height” of the displacement caused by its kinetic energy.

Therefore, due to the asymmetry between the gravitational potential of energy/mass and its kinetic energy in a closed system we call the universe one can understand why it will appear to be “flat” throughout its entire history based on the first law of thermodynamics and our experiences.

Later Jeff

Copyright 2008 Jeffrey O’Callaghan

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