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In this segment, we will examine what the modern cosmological model is, where it came from, and the key components of it. This will allow us to understand the role of expansion in that model as well as the role of the known evidence about expansion that is ignored in order for evolutionary cosmology to continue.

First, as we noted earlier, this model is based upon 3 foundational assumptions. And, as also indicated in the previous segment, it is important to state that these assumptions themselves are not necessitated by the observations.

The first assumption is homogeneity. Homogeneity refers to having a “uniform structure or composition throughout.”

“Homogeneity – 1: the quality or state of being homogeneous.” – Merriam-Webster’s Collegiate Dictionary

“Homogeneous – 1: of the same or a similar kind or nature 2: of uniform structure or composition throughout.” – Merriam-Webster’s Collegiate Dictionary

“Cosmos, Relativistic cosmologies, Einstein’s model – To derive his 1917 cosmological model, Einstein made three assumptions that lay outside the scope of his equations. The first was to suppose that the universe is homogeneous and isotropic in the large (i.e., the same everywhere on average at any instant in time), an assumption that the English astrophysicist Edward A. Milne later elevated to an entire philosophical outlook by naming it the cosmological principle.’” – Encyclopaedia Britannica 2004 Deluxe Edition

“Steady-State Theory, II THE STEADY-STATE THEORY – Both the big bang theory and the steady-state theory are based on what Bondi called the "cosmological principle." This principle states that on a large scale, the universe is homogeneous, meaning the universe looks about the same at every point, and isotropic, meaning the universe looks the same in every direction. Homogeneity and isotropy are not the same-for example, a universe that grows denser with distance from the observer would still look isotropic even though it is not homogeneous.” – "Steady-State Theory," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

“Cosmology, III MODERN COSMOLOGY, B Steady-State Theory – The big bang theory was framed in terms of what they called the cosmological principle-that the universe is homogeneous (the same in all locations) and isotropic (looks the same in all directions) on a large scale.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

As noted by the first quote above, homogeneity is intended to apply only to the universe on the large scale. Homogeneity is not intended to apply to the smaller-scale or local level of the universe. Thus, there may be a lack of homogeneity on smaller levels or regions of the universe. In particular, as indicated by the quotes below, homogeneity is said to be at work only on the very largest scale, superclusters, with dimensions larger than 100,000,000 light years. In other words, there is no “clustering of superclusters.” Superclusters are evenly distributed throughout the universe.

“Cosmos, Large-scale structure and expansion of the universe – Hubble inferred a uniformity in the spatial distribution of galaxies through number counts in deep photographic surveys of selected areas of the sky. This inference applies only to scales larger than several times [100,000,000] light-years. On smaller scales, galaxies tend to bunch together in clusters and superclusters, and Hubble deliberately avoided the more conspicuous examples in order not to bias his results. This clustering did excite debate among both observers and theorists in the earliest discussions of cosmology, particularly over the largest dimensions where there are still appreciable departures from homogeneity and over the ultimate cause of the departures. In the 1950s and early 1960s, however, attention tended to focus on homogeneous cosmological models because of the competing ideas of the big bang and steady state scenarios. Only after the discovery of the cosmic microwave background—which, together with the successes of primordial nucleosynthesis, signaled a clear victory for the hot big bang picture—did the issue of departures from homogeneity in the universe again attract widespread interest.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmos, Large-scale structure and expansion of the universe, Clustering of galaxies, Superclusters – In 1932 Harlow Shapley and Adelaide Ames introduced a catalog that showed the distributions of galaxies brighter than 13th magnitude to be quite different north and south of the plane of the Galaxy. Their study was the first to indicate that the universe might contain substantial regions that departed from the assumption of homogeneity and isotropy…Also apparent in the Shapley-Ames maps were three independent concentrations of galaxies, separate superclusters viewed from a distance. Astronomers now believe superclusters fill perhaps 10 percent of the volume of the universe. Most galaxies, groups, and clusters belong to superclusters, the space between superclusters being relatively empty. The dimensions of superclusters range up to a few times [100,000,000] light-years. For larger scales the distribution of galaxies is essentially homogeneous and isotropic—that is, there is no evidence for the clustering of superclusters.” – Encyclopaedia Britannica 2004 Deluxe Edition

The second assumption is isotropy. As indicated by the quotes below, isotropy refers to the idea that on a large scale the universe “looks the same in all directions.”

“Cosmos, Relativistic cosmologies, Einstein’s model – To derive his 1917 cosmological model, Einstein made three assumptions that lay outside the scope of his equations. The first was to suppose that the universe is homogeneous and isotropic in the large (i.e., the same everywhere on average at any instant in time), an assumption that the English astrophysicist Edward A. Milne later elevated to an entire philosophical outlook by naming it the cosmological principle.’” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmology, III MODERN COSMOLOGY, B Steady-State Theory – The big bang theory was framed in terms of what they called the cosmological principle-that the universe is homogeneous (the same in all locations) and isotropic (looks the same in all directions) on a large scale.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

It is important to note that homogeneity and isotropy are not the same. As the quote below explains, a universe may look isotropic without being homogeneous.

“Steady-State Theory, II THE STEADY-STATE THEORY – Both the big bang theory and the steady-state theory are based on what Bondi called the "cosmological principle." This principle states that on a large scale, the universe is homogeneous, meaning the universe looks about the same at every point, and isotropic, meaning the universe looks the same in every direction. Homogeneity and isotropy are not the same-for example, a universe that grows denser with distance from the observer would still look isotropic even though it is not homogeneous.” – "Steady-State Theory," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

It is also significant to note that isotropy is a concept based upon how the universe looks from the earth. This is indicated by the following quotes, but it is also implicit in common sense because where else would we have observed the universe from besides the earth?

“Universe, Size of the universe – No one knows for sure whether the universe is finite (limited) or infinite in size. Observations of the sky with optical telescopes indicate that there are at least 100 billion galaxies in the observable universe. Measurements show that the most distant galaxies observed to date are about 12 billion to 13 billion light-years from Earth. They appear in every direction across the sky.” – Worldbook, Contributor: Kenneth Brecher, Ph.D., Professor of Astronomy and Physics, Boston University.

“Universe, Size of the universe – Observations of the sky with optical telescopes indicate that there are at least 100 billion galaxies in the observable universe. Measurements show that the most distant galaxies observed to date are about 12 billion to 13 billion light-years from Earth. They appear in every direction across the sky.” – Worldbook, Contributor: Kenneth Brecher, Ph.D., Professor of Astronomy and Physics, Boston University.

Because isotropy is based upon how the universe looks from earth, as we stated earlier, unlike homogeneity and the extrapolation of a Big Bang explosion, isotropy is an assumption that is based upon observation. However, when isotropy makes claims about how the universe would look from other locations besides the earth, then it too becomes an assumption that goes beyond the observable evidence because we simply have no observations of the universe from any other location beside the earth on which to base such an extrapolation of isotropy. Finally, as also stated earlier, isotropy is just as much a part of the creationist model as it is the evolutionary model. In fact, for reasons that will be described later on, isotropy is arguably more indicative of the creationist model than the evolutionary model.

An additional assumption of modern cosmological models is that the universe has no edge or boundary, regardless of whether or not it is finite or infinite. Consequently, the idea that the universe has no boundary or edge results in a universe with no center.

“Big-bang model – The big-bang model is based on two assumptions. The first is that Albert Einstein's general theory of relativity correctly describes the gravitational interaction of all matter. The second assumption, called the cosmological principle, states that an observer's view of the universe depends neither on the direction in which he looks nor on his location. This principle applies only to the large-scale properties of the universe, but it does imply that the universe has no edge, so that the big-bang origin occurred not at a particular point in space but rather throughout space at the same time.” – Encyclopaedia Britannica 2004 Deluxe Edition

Taken as a whole, the model assumes that all matter is evenly distributed throughout the universe and there is no center to the distribution of that matter. As such, there are no “special” locations in the universe because all parts of the universe are uniform. Consequently, it could be said that the assumption that there is “no special place” in the universe, which forms the basis of the other assumptions. For example, Einstein’s original model, including its assumptions about homogeneity and isotropy, were outgrowths of what is known as “the Copernican revolution” or “the Copernican principle.”

“Cosmos, Relativistic cosmologies, Einstein’s model – To derive his 1917 cosmological model, Einstein made three assumptions that lay outside the scope of his equations. The first was to suppose that the universe is homogeneous and isotropic in the large (i.e., the same everywhere on average at any instant in time), an assumption that the English astrophysicist Edward A. Milne later elevated to an entire philosophical outlook by naming it the cosmological principle. Given the success of the Copernican revolution, this outlook is a natural one.” – Encyclopaedia Britannica 2004 Deluxe Edition

Nicolaus Copernicus was a scientists in the 1540’s A.D., who asserted that the earth was not the center of the universe as the Greek philosopher Aristotle has supposed, but instead, the sun was the center.

Copernicus unseated the idea that the earth had a special location in the universe as a result of divine purpose. And it was this principle, the premise that the earth does not have a special place in the universe, which evolutionary cosmologists admit was the assumption that “lead directly to” the Big Bang model.

“The idea that we are not located in a special spatial location has been crucial in cosmology leading directly to the [big bang theory].” – Richear Gott (Ph. D. Astrophysics), Implications of the Copernican principle for our future prospects, Nature, 1993 (Cited on “Astronomy and the Bible,” Mike Riddle, Copyright Northwester Creation Network, nwcreation.net)

And this fact was also affirmed in Britannica’s last comment above concerning Einstein’s assumptions about the uniform distribution of matter in the universe, which stated, “Given the success of the Copernican revolution, this outlook is a natural one.”

Since we have stated that modern cosmology views the universe as having no boundary or edge, this is a good time to make an important clarification. Often in cosmology, you will find the terms “bound” and “unbound universe.” These terms do NOT refer to whether or not the universe has an edge or boundary. The terms “open” or “unbound universe” refer, not to whether or not it has an edge or boundary, but instead refer to the notion that the universe will continue to expand forever. Conversely, the terms “closed” or “bound universe” refer to the notion that the universe will not expand forever, but will one day stop expanding and eventually collapse in a process opposite the big bang

“Cosmos – The issue of how the universe will end seems, at first sight, more amenable to conventional analysis. Because the universe is currently expanding, one may ask whether this expansion will continue into the indefinite future or whether after the passage of some finite time, the expansion will be reversed by the gravitational attraction of all of the matter for itself. The procedure for answering this question seems straightforward: either measure directly the rate of deceleration in the expansion of the galaxies to extrapolate whether they will eventually come to a halt, or measure the total amount of matter in the universe to see if there is enough to supply the gravitation needed to make the universe bound. Unfortunately, astronomers' assaults on both fronts have been stymied by two unforeseen circumstances. First, it is now conceded that earlier attempts to measure the deceleration rate have been affected by evolutionary effects of unknown magnitude in the observed galaxies that invalidate the simple interpretations. Second, it is recognized that within the Cosmos there may be an unknown amount of “hidden mass,” which cannot be seen by conventional astronomical techniques but which contributes substantially to the gravitation of the universe. The hope is that, somehow, quantum physics will ultimately supply theoretical answers (which can then be tested observationally and experimentally) to each of these difficulties.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmos, Relativistic cosmologies, Bound and unbound universes and the closure density – The different separation behaviours of galaxies at large time scales in the Friedmann closed and open models and the Einstein–de Sitter model allow a different classification scheme than one based on the global structure of space-time. The alternative way of looking at things is in terms of gravitationally bound and unbound systems: closed models where galaxies initially separate but later come back together again represent bound universes; open models where galaxies continue to separate forever represent unbound universes; the Einstein–de Sitter model where galaxies separate forever but slow to a halt at infinite time represents the critical case. The advantage of this alternative view is that it focuses attention on local quantities where it is possible to think in the simpler terms of Newtonian physics—attractive forces, for example. In this picture it is intuitively clear that the feature that should distinguish whether or not gravity is capable of bringing a given expansion rate to a halt depends on the amount of mass (per unit volume) present. This is indeed the case; the Newtonian and relativistic formalisms give the same criterion for the critical, or closure, density (in mass equivalent of matter and radiation) that separates closed or bound universes from open or unbound ones…If the actual cosmic average is greater than this value, the universe is bound (closed) and, though currently expanding, will end in a crush of unimaginable proportion. If it is less, the universe is unbound (open) and will expand forever.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmology, III MODERN COSMOLOGY, D The Universe Through Time – A fundamental issue addressed in cosmology is the future of the universe-whether the universe will expand forever or eventually collapse. The first case (eternal expansion) is known as an open universe, and the second case (eventual collapse) is known as a closed universe. A closed universe would require sufficiently high density to cause gravity to stop the universe's expansion and begin its contraction.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

“Cosmology, IV COSMOLOGICAL EVIDENCE – For a universe with very low density, the age of the universe would be directly related to its expansion rate. This universe would expand forever; this eternal expansion defines an open universe. If, on the other hand, the density of a universe is sufficiently high, the expansion rate is changing-slowing down as the universe ages. This universe would eventually stop expanding and begin contracting, which defines it as a closed universe.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

Currently, the question of whether or not the universe is bound or unbound, whether or not it will expand forever or eventually collapse back together, is considered unresolved in modern cosmology.

“Cosmos, Relativistic cosmologies, The ultimate fate of the universe – In the absence of definitive observational conclusions, one can only speculate on the possible fate of the actual universe. If the universe is unbound, the cosmological expansion will not halt, and eventually the galaxies and stars will all die, leaving the Cosmos a cold, dark, and virtually empty place. If the universe is bound, the mass-energy content in the distant but finite future will come together again; the cosmic background radiation will be blueshifted, raising the temperature of matter and radiation to incredible levels, perhaps to reforge everything in the fiery crucible of the big squeeze. Because of the development of structure in previous epochs, the big squeeze may not occur simultaneously everywhere at the end of time as its explosive counterpart, the big bang, seems to have done at the beginning of time. Discussions of recurring cycles of expansions and contractions thus remain highly speculative.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Universe, The future of the universe – Many studies indicate that the universe will continue to expand. Measurements of the brightness and redshift of supernovae in distant galaxies suggest that at the present time the expansion of the universe is accelerating. Observations of the CMB radiation provide evidence that the universe has the appropriate mixture of matter and energy to continue expanding. Both of these types of studies give similar predictions for the rate at which the universe is expanding. Theories of the universe based on the German-born physicist Albert Einstein's theory of general relativity allow for the possibility that all of the matter in the universe could come back together again in a big crunch. This would happen if the gravitational pull of all of the universe's matter was strong enough to overcome its expansion. The entire universe would eventually collapse and then explode, entering a new phase that might resemble the present one. However, studies of the CMB radiation strongly suggest that the universe has an infinite mass and volume and that it will expand forever.” – Worldbook, Contributor: Kenneth Brecher, Ph.D., Professor of Astronomy and Physics, Boston University.

However, the theoretical question of “bound or unbound” deals with understanding what will happen in the future and as such, it is not as important as the fact that evolutionary cosmology lacks an actual, working theory concerning the past events that brought about the universe that we do see today. A working origins theory must explain how the known conditions of the present arrived, but it does not need to define what will happen in a future. Since the future is unknown, it is perfectly acceptable for a theory not to be able to explain its unidentified characteristics. But, any viable origins theory must be able to explain the identified characteristics that know exist at the present.

With the clarification made that “bound and unbound” models refer to whether or not the universe will eventually contract or will expand forever and do not in any way refer to the question of whether or not the universe has an edge or boundary, we can return to the significance of the “no edge” concept.

The significance of the “no edge or boundary” concept is articulated in the following quote by Isaac Newton. If there is an edge to the distribution of matter, then there is also a center. And as Newton explains, if the universe has a center, then that center of matter is also a center of gravity, which in turn would pull all the matter back toward that central location.

“Cosmos, Large-scale structure and expansion of the universe, Gravitational theories of clustering – The fact that gravitation affects all masses may explain why the astronomical universe, although not uniform, contains structure. This natural idea, which is the basis of much of the modern theoretical work on the problem, had already occurred to Newton in 1692. Newton wrote to the noted English scholar and clergyman Richard Bentley: ‘It seems to me, that if the matter of our Sun & Planets & all ye matter in the Universe was eavenly scattered throughout all the heavens, & every particle had an innate gravity towards all the rest & the whole space throughout wch [sic] this matter was scattered was but finite: the matter on ye outside of this space would by its gravity tend towards all ye matter on the inside & by consequence fall down to ye middle of the whole space & there compose one great spherical mass. But if the matter was eavenly diffused through an infinite space, it would never convene into one mass but some of it convene into one mass & some into another so as to make an infinite number of great masses scattered at great distances from one to another throughout all yt infinite space. And thus might ye Sun and Fixt stars be formed supposing the matter were of a lucid nature.’” – Encyclopaedia Britannica 2004 Deluxe Edition

Most importantly, notice from the quote above that space being “infinite” was proposed by Newton as a solution to the problem of a gravity well at the center if space were finite. Specifically take note of Newton’s phrase “ye Sun and Fixt stars.”

Notice that Britannica’s comment on Einstein’s model describes Einstein’s assumptions as an outgrowth of Newton’s model, even with a reference to Newton’s phrase, “ye Sun and Fixt stars.” However, Einstein’s model altered the model proposed by Newton. As we will see, Einstein addressed the gravity well problem by supposing that space is curved like the surface of a sphere or a balloon. Because there is no center to the surface of a sphere, the problem of a center with a gravity well was avoided. Since Einstein proposed “curved space” as a solution to the gravity well problem, he did not need to suppose that space was infinite as Newton did, but was free to propose that space was finite. The “curvature” of space in Einstein’s model is explicitly stated in the first quote below. The second quote below also comments on this curvature by asserting that in Einstein’s model, parallel lines actually converge due to the warping and bending (i.e. curving) effect of gravity upon space. The centrality of the “no boundary or edge” assumption in Einstein’s model is explicitly stated in the last 2 quotes below.

“Cosmos, Relativistic cosmologies, Einstein's model – To derive his 1917 cosmological model, Einstein made three assumptions that lay outside the scope of his equations. The first was to suppose that the universe is homogeneous and isotropic in the large (i.e., the same everywhere on average at any instant in time), an assumption that the English astrophysicist Edward A. Milne later elevated to an entire philosophical outlook by naming it the cosmological principle. Given the success of the Copernican revolution, this outlook is a natural one. Newton himself had it implicitly in mind in his letter to Bentley (see above) when he took the initial state of the Cosmos to be everywhere the same before it developed ‘ye Sun and Fixt stars.’ The second assumption was to suppose that this homogeneous and isotropic universe had a closed spatial geometry. As described in the previous section, the total volume of a three-dimensional space with uniform positive curvature would be finite but possess no edges or boundaries (to be consistent with the first assumption).” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmos, Cosmological models, Early cosmological ideas – When one looks to great distances, one is seeing things as they were a long time ago, again because light takes a finite time to travel to Earth. Over such great spans, do the classical notions of Euclid concerning the properties of space necessarily continue to hold? The answer given by Einstein was: No, the gravitation of the mass contained in cosmologically large regions may warp one's usual perceptions of space and time; in particular, the Euclidean postulate that parallel lines never cross need not be a correct description of the geometry of the actual universe. And in 1917 Einstein presented a mathematical model of the universe in which the total volume of space was finite yet had no boundary or edge. The model was based on his theory of general relativity that utilized a more generalized approach to geometry devised in the 19th century by the German mathematician Bernhard Riemann.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Big-bang model – The big-bang model is based on two assumptions. The first is that Albert Einstein's general theory of relativity correctly describes the gravitational interaction of all matter. The second assumption, called the cosmological principle, states that an observer's view of the universe depends neither on the direction in which he looks nor on his location. This principle applies only to the large-scale properties of the universe, but it does imply that the universe has no edge, so that the big-bang origin occurred not at a particular point in space but rather throughout space at the same time.” – Encyclopaedia Britannica 2004 Deluxe Edition

Because Einstein’s “curved-space” model provided another means to avoid a centered-universe with a gravity well besides the assumption of an infinite universe, the question of whether or not the universe is infinite or finite became more or less irrelevant to cosmological models. In fact, whether or not the universe is infinite or finite remains an unresolved question in modern evolutionary theory.

“Cosmology, II EVOLUTION OF COSMOLOGICAL THEORIES, C Newton and Beyond – Beginning in the 17th century, scientists wondered why the sky was dark at night if space is indeed infinite (an idea proposed in ancient Greece and still accepted by most cosmologists today) and stars are distributed throughout that infinite space.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

“Cosmos, Cosmological models, Early cosmological ideas – Immediate issues that arise when anyone contemplates the universe at large are whether space and time are infinite or finite. And after many centuries of thought by some of the best minds, humanity has still not arrived at conclusive answers to these questions.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Universe, Size of the universe – No one knows for sure whether the universe is finite (limited) or infinite in size. Observations of the sky with optical telescopes indicate that there are at least 100 billion galaxies in the observable universe. Measurements show that the most distant galaxies observed to date are about 12 billion to 13 billion light-years from Earth. They appear in every direction across the sky.” – Worldbook, Contributor: Kenneth Brecher, Ph.D., Professor of Astronomy and Physics, Boston University.

More importantly, as indicated above the result of Einstein’s model is that the overall shape of the universe could be described analogously to the surface of a sphere, in which parallel lines would converge due to the bending or curving of space by gravity. As Einstein’s original model of the universe was modified, the illustrations for the “shape” of the universe were also modified. We can learn a lot about the shape of the universe in modern cosmology by following the progression of these illustrations.

The first illustration is described early on in quote below, where Einstein’s original 1917 model of space (not time) can be represented by a piece of graph paper “rolled up into a cylinder on its side.”

“Cosmos, Gravitation and the geometry of space-time – The principle of equivalence in general relativity allows the locally flat space-time structure of special relativity to be warped by gravitation, so that (in the cosmological case) the propagation of the photon over thousands of millions of light-years can no longer be plotted on a globally flat sheet of paper. To be sure, the curvature of the paper may not be apparent when only a small piece is examined, thereby giving the local impression that space-time is flat (i.e., satisfies special relativity). It is only when the graph paper is examined globally that one realizes it is curved (i.e., satisfies general relativity). In Einstein's 1917 model of the universe, the curvature occurs only in space, with the graph paper being rolled up into a cylinder on its side, a loop around the cylinder at constant time having a circumference of 2?R—the total spatial extent of the universe. Notice that the “radius of the universe” is measured in a “direction” perpendicular to the space-time surface of the graph paper. Since the ringed space axis corresponds to one of three dimensions of the actual world (any will do since all directions are equivalent in an isotropic model), the radius of the universe exists in a fourth spatial dimension (not time) which is not part of the real world. This fourth spatial dimension is a mathematical artifice introduced to represent diagrammatically the solution (in this case) of equations for curved three-dimensional space that need not refer to any dimensions other than the three physical ones. Photons traveling in a straight line in any physical direction have trajectories that go diagonally (at 45° angles to the space and time axes) from corner to corner of each little square cell of the space-time grid; thus, they describe helical paths on the cylindrical surface of the graph paper, making one turn after traveling a spatial distance 2?R. In other words, always flying dead ahead, photons would return to where they started from after going a finite distance without ever coming to an edge or boundary. The distance to the “other side” of the universe is therefore ?R, and it would lie in any and every direction; space would be closed on itself. Now, except by analogy with the closed two-dimensional surface of a sphere that is uniformly curved toward a centre in a third dimension lying nowhere on the two-dimensional surface, no three-dimensional creature can visualize a closed three-dimensional volume that is uniformly curved toward a centre in a fourth dimension lying nowhere in the three-dimensional volume. Nevertheless, three-dimensional creatures could discover the curvature of their three-dimensional world by performing surveying experiments of sufficient spatial scope.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmology, II EVOLUTION OF COSMOLOGICAL THEORIES, D Discovering the Structure of the Universe – In 1915 German-American physicist Albert Einstein, who was working in Switzerland, advanced a theory of gravitation known as the general theory of relativity. His theory involves a four-dimensional space-time continuum that bends in the presence of massive objects. This bending causes light and other objects that are moving near these massive objects to follow a curved path, just as a golfer's ball curves on a warped putting green. In this way, Einstein explained gravity.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

Einstein’s 1917 model was later modified by Russian meteorologist and mathematician Aleksandr A. Friedmann in 1922 and Georges Lemaitre in 1927. Their models, along with Einstein’s, still provide the basis of cosmology today.

“Cosmology, II EVOLUTION OF COSMOLOGICAL THEORIES, D Discovering the Structure of the Universe – Einstein's theory also made several predictions that were not part of Newton's theory. When these predictions were verified, Einstein's theory was accepted. Einstein's equations were very complicated, though, and it was other scientists who eventually found widely accepted solutions to Einstein's equations. Most of cosmology today is based on the set of solutions found in the 1920s by Russian mathematician Alexander Friedmann. Dutch astronomer Willem de Sitter and Belgian astronomer Georges Lemaitre also developed cosmological models based on solutions to Einstein's equations. ” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

As indicated below, Friedmann and Lemaitre’s models correspond to “big bang cosmologies,” meaning that they are earlier Big Bang cosmological models and they are part of the evolution to the current form of the Big Bang theory. Their models maintained Einstein’s assumptions of homogeneity and isotropy.

“Cosmos, Relativistic cosmologies, Friedmann-Lemaître models – In 1922 Aleksandr A. Friedmann, a Russian meteorologist and mathematician, and in 1927 Georges Lemaitre, the aforementioned Belgian cleric, independently discovered solutions to Einstein's equations that contained realistic amounts of matter. These evolutionary models correspond to big bang cosmologies. Friedmann and Lemaitre adopted Einstein's assumption of spatial homogeneity and isotropy (the cosmological principle).” – Encyclopaedia Britannica 2004 Deluxe Edition

“Astrophysics, IV THE STUDY OF THE UNIVERSE – In 1922 the Russian astronomer Alexander Friedmann proposed that the universe is everywhere filled with the same amount of matter. Using Albert Einstein's general theory of relativity to calculate the gravitational effects, he showed that such a system must originate in a singular state of infinite density (now called the big bang) and expand from that state in just the way Hubble observed.” – "Astrophysics," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

However, Friedmann’s and Lemaitre’s models rejected Einstein’s third assumption that the universe is static and does not change with time. This is important because Einstein’s 1917 model was effectively a primitive form of the Steady-State model since Einstein’s third assumption was that space doesn’t change over time.

“Cosmos, Relativistic cosmologies, Einstein’s model – To derive his 1917 cosmological model, Einstein made three assumptions that lay outside the scope of his equations…The third assumption made by Einstein was that the universe as a whole is static—i.e., its large-scale properties do not vary with time. This assumption, made before Hubble's observational discovery of the expansion of the universe…the philosophical attraction of the notion that the universe on average is not only homogeneous and isotropic in space but also constant in time was so appealing that a school of English cosmologists—Hermann Bondi, Fred Hoyle, and Thomas Gold—would call it the perfect cosmological principle and carry its implications in the 1950s to the ultimate refinement in the so-called steady state model.” – Encyclopaedia Britannica 2004 Deluxe Edition

In contrast, by assuming that the universe evolved with time the models proposed by Friedmann in 1922 and Lamaitre in 1927 “anticipated” Hubble’s discovery of expansion in 1929 (as indicated by the second quote below).

“Cosmos, Relativistic cosmologies, Friedmann-Lemaître models – The decision to abandon a static model meant that the Friedmann models evolve with time. As such, neighbouring pieces of matter have recessional (or contractional) phases when they separate from (or approach) one another with an apparent velocity that increases linearly with increasing distance. Friedmann's models thus anticipated Hubble's law before it had been formulated on an observational basis. It was Lemaître, however, who had the good fortune of deriving the results at the time when the recession of the galaxies was being recognized as a fundamental cosmological observation, and it was he who clarified the theoretical basis for the phenomenon.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmology, II EVOLUTION OF COSMOLOGICAL THEORIES, D Discovering the Structure of the Universe – In 1929 Hubble had measured enough spectra of galaxies to realize that the galaxies' light, except for that of the few nearest galaxies, was shifted toward the red end of the visible spectrum. This shift increased the more distant the galaxies were. Cosmologists soon interpreted these red shifts as Doppler shifts, which showed that the galaxies were moving away from the earth…This constant relationship between distance and speed led cosmologists to believe that the universe is expanding uniformly.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

This is why Hubble’s discovery of expansion is so central to modern cosmology. Effectively, it was the discovery of expansion that marked the demise of Steady-State models, including Einstein’s original 1917 model, by proving that in the large-scale the universe was changing over time, namely the change of expansion. Consequently, as described in the quote below, expansion actually changes the “shape” of the universe. Einstein’s original 1917 “cylinder” curve model was altered in accordance with the work of Friedmann and Lamaitre. Specifically, the addition of “change over time” transformed Einstein’s cylinder into the image of a “barrel on its side,” with the new curves at both ends of the “barrel” representing that temporal change caused by expansion.

“Cosmos, Relativistic cosmologies, Friedmann-Lemaître models – The geometry of space in Friedmann's closed models is similar to that of Einstein's original model; however, there is a curvature to time as well as one to space. Unlike Einstein's model, where time runs eternally at each spatial point on an uninterrupted horizontal line that extends infinitely into the past and future, there is a beginning and end to time in Friedmann's version of a closed universe when material expands from or is recompressed to infinite densities. These instants are called the instants of the “big bang” and the “big squeeze,” respectively. The global space-time diagram for the middle half of the expansion-compression phases can be depicted as a barrel lying on its side. The space axis corresponds again to any one direction in the universe, and it wraps around the barrel. Through each spatial point runs a time axis that extends along the length of the barrel on its (space-time) surface. Because the barrel is curved in both space and time, the little squares in the grid of the curved sheet of graph paper marking the space-time surface are of nonuniform size, stretching to become bigger when the barrel broadens (universe expands) and shrinking to become smaller when the barrel narrows (universe contracts). It should be remembered that only the surface of the barrel has physical significance; the dimension off the surface toward the axle of the barrel represents the fourth spatial dimension, which is not part of the real three-dimensional world. The space axis circles the barrel and closes upon itself after traversing a circumference equal to 2?R, where R, the radius of the universe (in the fourth dimension), is now a function of the time t. In a closed Friedmann model, R starts equal to zero at time t = 0 (not shown in barrel diagram), expands to a maximum value at time t = t m (the middle of the barrel), and recontracts to zero (not shown) at time t = 2t m, with the value of t m dependent on the total amount of mass that exists in the universe.”– Encyclopaedia Britannica 2004 Deluxe Edition

This “barrel on its side” concept of the universe is depicted in the following illustration from Britannica Encyclopedia and the subsequent caption below.

“Cosmos, Relativistic cosmologies, Friedmann-Lemaître models – Curved space-time in a matter-dominated, closed universe during the middle half of its expansion-compression phases. At each instant of time t, the space axis forms a closed loop with radius R(t), the so-called radius of the universe, in an unobservable fourth dimension. – From F.H. Shu, The Physical Universe (1982); University Science Books.” – Encyclopaedia Britannica 2004 Deluxe Edition

In 1932, Einstein and de Sitter proposed another modification to the basic model. This 1932 model assumed that space is infinite and curved, and most importantly, it retained the assumptions of homogeneity and isotropy.

“De Sitter, Willem – His work also helped familiarize astronomers with the theory of relativity proposed by German-born American astronomer Albert Einstein…In 1932 Einstein and de Sitter collaborated and refined both men's earlier cosmological theories to create the Einstein-de Sitter model of the universe. This model was the first prediction that dark matter, or matter that does not emit electromagnetic radiation and so had not yet been detected, should exist in the universe. See also Cosmology; Big Bang Theory; Steady-State Theory.” – "De Sitter, Willem," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

“Cosmos, Relativistic cosmologies, The Einstein–de Sitter universe – In 1932 Einstein and de Sitter proposed that the cosmological constant should be set equal to zero, and they derived a homogeneous and isotropic model that provides the separating case between the closed and open Friedmann models; i.e., Einstein and de Sitter assumed that the spatial curvature of the universe is neither positive nor negative but rather zero. The spatial geometry of the Einstein–de Sitter universe is Euclidean (infinite total volume), but space-time is not globally flat (i.e., not exactly the space-time of special relativity). Time again commences with a big bang and the galaxies recede forever, but the recession rate (Hubble's “constant”) asymptotically coasts to zero as time advances to infinity.” – Encyclopaedia Britannica 2004 Deluxe Edition

Although modified by additional support components, like inflation theory, the Einstein-de Sitter Big Bang cosmology remains the basic model today.

“Cosmos, Cosmological models, The very early universe, Inflation – Cosmic inflation serves a number of useful purposes. First, the drastic stretching during inflation flattens any initial space curvature, and so the universe after inflation will look exceedingly like an Einstein–de Sitter universe.” – Encyclopaedia Britannica 2004 Deluxe Edition

“Cosmos, Relativistic cosmologies, Relativistic cosmologies, Einstein's model, The Einstein–de Sitter universe – Because the geometry of space and the gross evolutionary properties are uniquely defined in the Einstein–de Sitter model, many people with a philosophical bent have long considered it the most fitting candidate to describe the actual universe. During the late 1970s strong theoretical support for this viewpoint came from considerations of particle physics (the model of inflation to be discussed below), and mounting, but as yet undefinitive, support also seems to be gathering from astronomical observations.”

Consequently, the final modern concept of the model can be illustrated like the surface of a “sphere” or “balloon,” as depicted in the following illustration from Microsoft Encarta. In the illustration and its caption, we can see how the spherical surface of a balloon represents both the “curvature” of space as well as how space expands.

“Expanding Universe Experiment – One way to understand the concept of an expanding universe is to draw dots, representing galaxies, on a balloon. As the balloon is inflated, each dot moves away from all the others. To a person viewing the universe from a galaxy, all other galaxies would seem to be receding. The distant galaxies appear to be moving away faster than the near ones, which demonstrates Hubble's law. Some astronomers believe that this expansion will continue forever, whereas others think that at a certain point the universe will begin contracting. “ – Encarta, Microsoft Corporation. All Rights Reserved.

To summarize, only 2 out of Einstein’s 3 original assumptions have been retained in modern cosmology. Those 2 remaining assumptions are homogeneity and isotropy. Both of these 2 assumptions reflect the notion that on the large scale the distribution of matter in universe is roughly the same everywhere. Einstein’s third assumption was that on the large scale the universe remains the same over time, an assumption which has since been disproved by expansion.

Now that we understand what the basic model of the universe looks like, at least by way of analogy, we can discuss the relevance of this model. As we have seen throughout the quotes above, from Aristotle to Einstein’s original model in 1917 to the modern adoptions of the 1932 Einstein-de Sitter model, the primary factor in this model is what has been called the Copernical principle, which is the preference for a universe in which earth, its solar system, and its galaxy are not near the center and have no special place in the universe. A few additional comments need to be made with regard to this “Copernican” ideology.

First, the fact that the Roman Catholic Church of Copernicus’ day strongly opposed his sun-centered theory is often cited as an analogy to modern creationism as a criticism that creationism is a return to the backward science of the Middle Ages under the Church in which observable reality is suppressed by blind faith. But this is not true for several reasons.

Number one, as indicated by the quotes below, the Roman Catholic Church was simply upholding an ancient secular, Gentile, or Pagan cosmological view put forward by Aristotle and Ptolemy, not the Bible. Consequently, this historical episode is an example of the problems that ensue when the texts of the Bible are bent out of their context to support the ideas of secular science.

“Astronomy, History – Aristotle's system of physics and astronomy, developed in the 300's B.C., survived for almost 2,000 years. In Aristotle's system of astronomy, Earth was the center of the universe. During the A.D. 100's, Ptolemy modified Aristotle's system to account for the retrograde motion of the planets. Ptolemy also maintained that Earth was the center of the universe, however. Developing the modern view – By the early 1500's, Nicolaus Copernicus had developed a theory in which Earth and the other planets revolved about the sun…In 1609, Galileo heard that an optical device had been built that made distant objects appear closer. He soon built his own telescope. The discoveries Galileo made with this instrument backed the Copernican theory over the theories of Aristotle and Ptolemy. In 1616, however, the Roman Catholic Church warned Galileo not to teach that Earth revolves about the sun. A book of Galileo's published in 1632 was interpreted as a violation of the ban, and Galileo was put under house arrest. Only in 1992 did the Catholic Church confirm that Galileo should not have been tried or convicted.” – Worldbook, Contributor: Jay M. Pasachoff, Ph.D., Field Memorial Professor of Astronomy and Director, Hopkins Observatory of Williams College.

“Cosmology, II EVOLUTION OF COSMOLOGICAL THEORIES, A Ancient Cosmologies – Until the 16th century, most people (including early astronomers) considered the earth to be at the center of the universe…B Sun-Centered Universe – The ideas of Ptolemy were accepted in an age when standards of scientific accuracy and proof had not yet been developed. Even when Polish astronomer Nicolaus Copernicus developed his model of a sun-centered universe in the 1540s, he based his ideas on philosophy instead of new observations. Copernicus's theory was simpler and therefore more sound philosophically than the idea of an earth-centered universe. A sun-centered universe neatly explained why Mars appears to move backward across the sky: Because Earth is closer to the sun, Earth moves faster than Mars. When Mars is ahead of or relatively far behind Earth, Mars appears to move across Earth's night sky in the usual west-to-east direction. As Earth overtakes Mars, Mars's motion seems to stop, then begin an east-to-west motion that stops and reverses when Earth moves far enough away again. Copernicus's model also explained the daily and yearly motion of the sun and stars in the earth's sky. Scientists were slow to accept Copernicus's model of the universe, but followers grew in number throughout the 16th century. By the mid-17th century, most scientists in western Europe accepted the Copernican universe.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

“Astronomy, Observing the sky, Earth-centered theories – Ancient scholars produced elaborate schemes to account for the observed movements of the stars, sun, moon, and planets. In the 300's B.C., the Greek philosopher Aristotle developed a system of 56 spheres, all with the same center. The innermost sphere, which did not move, was Earth. Around Earth were 55 transparent, rotating spherical shells. The outermost shell carried the stars, believed to be merely points of light. Other shells carried the sun, moon, and planets. These shells rotated inside other shells that rotated within still other shells in ways that accounted for almost all the observed movements. During the A.D. 100's, Ptolemy, a Greek astronomer who lived in Alexandria, Egypt, offered an explanation that better accounted for retrograde motion. Ptolemy said that the planets moved in small circles called epicycles. The epicycles moved in large circles called deferents. Earth was near the center of all the deferents. Sun-centered theories – By the early 1500's, the Polish astronomer Nicolaus Copernicus had developed a theory in which the sun was at the center of the universe. This theory correctly explained retrograde motion as the changing view of the planets as seen from a moving Earth. The theory also correctly explained the east-to-west movement of the sun and stars across the sky. This movement is due to the west-to-east rotation of Earth about its own axis, rather than an actual motion of the sun and stars.” – Worldbook, Contributor: Jay M. Pasachoff, Ph.D., Field Memorial Professor of Astronomy and Director, Hopkins Observatory of Williams College.

Number 2, the suggestion that the Bible teaches the sun revolves around the earth requires an erroneous interpretive leap that takes the passage far beyond the normal usage of the expressions in the passage. The passage in question is Joshua 10:12-13, which was misapplied to support the earth-centered universe of the ancient pagan Greeks and Egyptians.

To illustrate, notice that the last quote from Worldbook above asserts that Copernicus’ theory “correctly explained the east-to-west movement of the sun and stars across the sky.” Likewise, the quote from Microsoft Encarta states that Copernicus’ theory “neatly explained why Mars appears to move backward across the sky.” When we read such statements from modern reference books, we don’t assume that the authors believe that the sun, stars, or Mars actually move across the sky or that it is their intention to communicate that idea. Likewise, when we hear modern people refer to sunrise or sundown, we don’t assume that they believe the sun is moving around the earth. Instead, we assume they are either speaking poetically or casually without intending their words as technical descriptions of the structure of the universe. Yet, when we read a passage in the Bible such as Joshua 10:12-13, which similarly states “the sun stood still in the midst of heaven,” why do we interpret that statement differently as though it actually is intended as a technical description of the structure of the universe? Why the double standard?

The reason is simple. Effectively, we would be mistakenly interpreting the Bible in light of our presumption that these were more primitive people who had wrong ideas about the structure of the universe, in which case our preconceived biases are causing us to interpret the text differently than we would if we heard the same words uttered in common speech today. However, one of the rules in the interpretive, textual science of hermeneutics is that figures of speech in the text must be taken as figures of speech, rather than taken literally. Joshua 10 is simply a classic case of misinterpreting a text, taking a common figure of speech, such as the ones we see in Worldbook and Encarta above, and interpreting it literally. In the case of the Roman Catholic Church in Copernicus’ day, their misinterpretation was motivated by a desire to uphold the current, secular scientific view of their day, which had been advanced by Aristotle and Ptolemy. In the case of modern persons, the misinterpretation is the result of approaching the text with the presumption that evolution, including cultural evolution, is true and then interpreting the text in light of those assumptions rather than letting it speak for itself and judging its words in the same manner we would if we read or heard them anywhere else.

For these reasons, it is incorrect to conclude that the episode between Copernicus and Aristotle exemplifies creationism suppressing observable reality in favor of blind faith. Instead, what really occurred was a highly-syncretistic form of Christianity made a presumptuous interpretation of a casual, everyday statement taken out of context from an isolated passage in order to bend support toward an erroneous secular scientific view proposed by Aristotle and Ptolemy, not the Bible.

But more importantly, notice that the first quote above states that “simpler” theories and explanations of the existing observations are considered superior and preferable to complicated ones.

“Cosmology, II EVOLUTION OF COSMOLOGICAL THEORIES, B Sun-Centered Universe – Even when Polish astronomer Nicolaus Copernicus developed his model of a sun-centered universe in the 1540s, he based his ideas on philosophy instead of new observations. Copernicus's theory was simpler and therefore more sound philosophically than the idea of an earth-centered universe.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

This suggestion will become more and more relevant as we explore the known evidence about expansion and its implications for cosmological models.

It should also be pointed out that Copernicus’ model does not stand. As indicated by the quotes above Copernicus merely replaced the earth-centered universe with a universe in which the sun was the center. Scientists now know that our sun is not the center of the universe either.

“Cosmology, II EVOLUTION OF COSMOLOGICAL THEORIES, D Discovering the Structure of the Universe – In 1917 American scientist Harlow Shapley measured the distance to several groups of stars known as globular clusters. He measured these distances by using a method developed in 1912 by American astronomer Henrietta Leavitt. Leavitt's method relates distance to variations in brightness of Cepheid variables, a class of stars that vary periodically in brightness. Shapley's distance measurements showed that the clusters were centered around a point far from the sun. The arrangement of the clusters was presumed to reflect the overall shape of the galaxy, so Shapley realized that the sun was not in the center of the galaxy. Just as Copernicus's observations revealed that the earth not at the center of the universe, Shapley's observations revealed that the sun was not at the center of the galaxy. Cosmologists now realize that the earth and sun do not occupy any special position in the universe.” – "Cosmology," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.

“Astronomy – The Milky Way is about 100,000 light-years across, and the sun is roughly 25,000 light-years from its center.” – Worldbook, Contributor: Jay M. Pasachoff, Ph.D., Field Memorial Professor of Astronomy and Director, Hopkins Observatory of Williams College.

The fact that Copernicus’ own model has been rejected highlights what is actually embraced about Copernicus. It is not his view of the universe, but simply his basic rejection of the idea that the earth has special or central place in the universe. It is not difficult to understand why evolutionary science embraces such a preference. Such a central or special location for the earth is rejected on the grounds that it indicates teleology, a purposeful placement of the earth in a specific location. And as we can see, from Einstein’s original model in 1917 right through the modifications to the 1932 Einstein-de Sitter universe which serves as the basis for Big Bang cosmology to this day, the model is formulated on the basis of assumptions and philosophical preferences, which themselves stem from this Copernican principle in which the earth has not central or special place in the universe.

(Continued…)