Recent results from the Wilkinson Microwave Anisotropy Probe (WMAP) confirmed that the universe is mainly made of “Dark Energy” thought to be responsible for the current acceleration of its expansion. But what would happen if the rate of acceleration remained constant or increased with time? The answer according to some is a “Big Rip” in which the accelerated expansion of the universe becomes infinite in finite time, finally overcoming all forces, including the nuclear force that binds the quarks in neutrons and protons together.
However most cosmologist would agree that before we can make any assumptions as to how Dark Energy will affect the evolution of our universe we should first try to understand what it is and how it interacts with its environment in terms of observations and our currently accepted theoretical models.
For example one of the most obvious problems of assuming the universe will Rip apart is that it violates one of most treasured laws of physics that of the law of conservation of mass/energy.
That law tells us the kinetic energy of the universe’s expansion associated with the big bang and the accelerative forces of Dark Energy cannot exceed the total combined energy of its energy/mass. However that is exactly what would have to happen for the Big Rip to occur.
For example for a rocket to escape or be “Rip” from the earth’s gravitational influence one must provide it with more kinetic energy than the combined gravitational potential of both its and the earth’s energy/mass.
Similarly for the universe to be “Rip” apart one would have to provide its components with enough kinetic energy to overcome the total gravitational potential of its energy/mass.
However as was just mentioned the law of conservation energy/mass tells us that since by definition the universe is a closed system the kinetic energy of the universe’s components cannot exceed the gravitational potential of its energy/mass.
Therefore if we are to assume that the universe will be Rip apart by Dark Energy we must also assume that energy/mass can be created and that the law of conservation of energy/mass is invalid.
However as also mentioned early the best way of to understand why the Big Rip” cannot occur is to show, using the currently accepted theoretical models and laws of physics to understand why Dark energy is causing the accelerated expansion of our universe and why, based on those laws and theoretical models it theoretical models why it cannot possibly cause it to be rip apart.
Einstein’s General Theory of Relativity, the previewing theory governing the evolution of the universe tells us that its future depends the interaction of the contractive force of gravity, the expansive force associated with the kinetic energy left over from the Big bang and Dark Energy.
Unfortunately in its present form it cannot address the causality of the expansive force of Dark Energy and how or why it would interact with its environment to cause it to accelerate because observations tell us that three-dimensional space is expanding towards a higher spatial dimension not a time or space-time dimension.
Therefore, in order to explain the observed spatial expansion of the universe one would have to assume the existence of a another *spatial* or fourth *spatial* dimension in addition to the three spatial dimensions and one time dimension that Einstein’s theories contain to account for that observation.
This would be true if Einstein had not given us a means of qualitatively and quantitatively converting the geometric properties of his space-time universe to one consisting of only four *spatial* dimensions.
He did this when he defined its geometric properties in terms of the equation E=mc^2 and the constant velocity of light because it allows one to redefine a unit of time he associated with energy in his space-time universe to an equivalent unit of space in a universe consisting of only four *spatial* dimensions.
In other words by defining the geometric properties of a space-time universe in terms of the equation E=mc^2 and the constant velocity of light he provided a qualitative and quantitative means of redefining it in terms of the geometry of four *spatial* dimensions.
The fact that the equation E=mc^2 allows us to quantitatively and qualitatively derive the physical properties of energy in a space-time universe in terms of its spatial properties is the bases for assuming, as was done in the article “Defining energy†Nov 27, 2007 that all forms of energy can be derived in terms of a spatial displacement in a “surface” of a three-dimensional space manifold with respect to a fourth *spatial* dimension.
As mentioned earlier it is difficult to integrate the causality of why three-dimensional space expanding towards a “higher” spatial dimension into Einstein space-time universe because it does not define a higher spatial dimension.
However it is easy if one reformulates it, as was shown above to be possible in terms higher fourth *spatial* dimension because a higher dimension is an integral part of its theoretical structure.
Yet this also allows one to understand how and why the force called Dark Energy is causing an accelerated spatial expansion of our universe in terms of the laws of thermodynamics because it gives one the ability, as mentioned earlier to use Einstein’s equations to qualitatively and quantitatively define energy in terms of a spatial displacement in a “surface” of a three-dimensional space manifold with respect to a fourth *spatial* dimensions.
We know from the study of thermodynamics that energy flows from areas of high density to one of low density very similar to how water flows form an elevated or “high density” point to a lower one.
For example, if the walls of an above ground pool filled with water collapse the elevated two-dimensional surface of the water will flow or expand and accelerate outward towards the three-dimensional environment surrounding it while the force associated with that expansion decreases as it expands.
Yet we know from observations of the cosmic background radiation that presently our three-dimensional universe has an average energy component equal to about 3.7 degrees Kelvin.
However this means according to concepts developed in the article “Defining energy” that the three-dimensional “surface” occupied by the particles in our universe which has an average energy component of 3.7 degree Kelvin would be elevated with respect to a fourth *spatial* dimension.
Yet this means similar to the water molecules occupying the elevated two dimensional surface of the water in the pool, the particles occupying a region of three-dimensional space that is elevated because of its 3.7 degree temperature will flow and accelerate outward in the four dimensional environment surrounding it.
In other words by reformulating Einstein’s theories in terms of four *spatial* dimensions one can use the laws of thermodynamics to explain what the force called Dark Energy is and why it is causing the accelerated expansion of the universe in terms of Einstein’s theories.
Many feel that because space is everywhere, the force called Dark Energy is everywhere so therefore its effects will increase as space expands. In contrast, gravity’s force is stronger when things are close together and weaker when they are far apart. Therefore they feel the rate at which the universe expands will increase as time go by resulting in galaxies, stars, the solar system, planets, and even molecules and atoms would be shredded by the ever-faster expansion. In other words the universe that was born in a violent expansion could end with an even more violent expansion called the Big Rip.
However if the above theoretical model is correct than the magnitude of Dark Energy relative to gravitational energy will not continue to increase as the universe expands but will decrease because, similar to the water in a collapsed pool the accelerative forces associated with its will decline as it expands.
Yet, because the laws of conservation the total quantity of the universe’s energy/mass remains constant throughout its history its gravitational potential will also. Therefore in the future the gravitational contractive forces associated with it will exceed the expansive forces associated with Dark Energy because, as mentioned earlier according to this theoretical model its accelerative forces should decrease as the universe expands.
This would be true even though its components may be separated by extremely large distances because, as just mentioned if the above theoretical scenario is correct the force associated with dark energy will decease relative to gravity as time goes by.
However observations also suggest that early in the universe evolution the gravitational forces exceeded the expansive forces of Dark Energy.
The reason is that according the above theoretical model, just after the big bang when the concentration of energy and mass was high, the gravitational forces with it would predominate over Dark Energy because the distance between both its energy and mass components was relatively small.
However as the universe expands its gravitational attractive forces will decrease more rapidly than the expansive force associated with Dark Energy because they are related to the square of the distance between them while those of the expansive forces of Dark Energy are more closely related to a linear function of the total energy of content of the universe.
Therefore after a given period of time the expansive forces associated with Dark Energy will become predominate and the expansion of the universe will accelerate.
However as the universe expands and cools that force will decrease because as mentioned earlier similar to the two-dimensional surface of the water in a collapsed pool, the forces associated with it will decrease as it expands.
This means that eventually gravitational forces will predominant because, as mentioned earlier the laws of thermodynamics tells us the total accelerative forces associated with Dark Energy will decease and therefore will eventually approach zero, while the total mass content and the gravitational attractive forces associated with it will remain constant as the universe expands even though they may be separated by a greater distant.
Therefore. gravity will eventually win the battle with Dark Energy because as was just mentioned the forces associated with it approach zero as the expansion progress while those of gravity remain constant.
There can be no other conclusion if one accepts the validity of Einstein’s theories and the laws of thermodynamics because the theoretical arguments presented are a base solely on their validity.
In other words if someone spends the time, as we done above analyzing what observations have taught us about Dark Energy and integrating them into Einstein’s Theories one would one find that the assumption that it would “Rip” the universe apart does not have foundation in logic or science.
It should be remember that Einstein’s genius allows us to choose whether to view Dark Energy in either a space-time environment or one consisting of four *spatial* dimension when he defined the geometry of space-time in terms of energy/mass and the constant velocity of light.
Later Jeff
Copyright 2015 Jeffrey O’Callaghan