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Non-standard cosmology

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A non-standard cosmology is a cosmological theory that contradicts the standard model of cosmology. The term has been used since the late 1960s after the discovery of the cosmic background radiation (CBR) in 1965 by Penzias and Wilson. These observations combined with observations of big bang nucleosynthesis and other evidence suggesting that the universe was evolving caused most cosmologists to favor the Big Bang theory over the steady state theory.

While non-standard models, including the steady-state theory, often have explanations for phenomenon for observations such as cosmic microwave background, which is seen as residual radiation from old stars, most cosmologists as of 2004, believe that the big bang theory provides a more coherent view of the universe that more closely fits observations.

Since around the time of the observation of the CBR, in practice a non-standard cosmology has primarily meant any cosmological theory which argues that the Big Bang theory is fundamentally incorrect. While there are a number of observations which are not currently explained well by big bang cosmologies, the prevailing opinion among cosmologists is that these observations can be incorporated within a big bang cosmology without major changes to the foundations of the theory. However, non-standard cosmologies assert that this procedure will fail and to coherently address these issues from a framework which is not in contradiction to empirical observation and experiment will require a basic reevaluation of the standard model.

Table of contents
1 Standard model
2 See also
3 Bibliography
4 External links and references

Standard model

The standard model of cosmology has asserted that:

Non-standard cosmologies minimally challenge one or both of these beliefs, usually asserting that one or the other of these beliefs are incorrect. Alternative models of cosmology that do not challenge the two assertions above are not termed non-standard cosmologies, even if they are not widely accepted. For example, the modified Newtonian dynamics is not a non-standard cosmology even though it radically challenges mainstream views on gravity.

Another example of a radical, controversial idea that is not considered a non-standard cosmology is the highly speculative and controversial idea that is the ekpyrotic universe which holds that the expansion of the universe began in the collision of two branes in the higher dimensional "bulk" of brane cosmology. Although radical, this cosmology is an extension of, rather than a competitor to, the big bang theory.

Objections to the Standard Model

There are a number of general objections to the standard model which have been advanced by supporters of non-standard cosmologies. The first is that the standard model presupposes a beginning to the universe and fails to answer the question of what happened before the beginning. The second is that the big bang requires esoteric physics.

In addition there are specific objections to the big bang. Since the 1970's, at any one moment, there have been observations which the big bang theory does not appear to explain well. However, these observations have been handled by making refinements and enhancements to the basic model, and so the list of observations which most cosmologists feel are unexplained, has changed over time.

Supporters of non-standard cosmologies claim that these modifications and enhancements to the big bang model are ad-hoc and incoherent, and have produced an overly complex and inelegant theory. For instance, in an 'Open Letter to the Scientific Coummunity,' signed by scores of cosmologists around the world, including Hermann Bondi, and published in the May 22nd 2004 issue of the New Scientist periodical, they protest that:

Without the hypothetical inflation field, the big bang does not predict the smooth, isotropic cosmic background radiation that is observed, because there would be no way for parts of the universe that are now more than a few degrees away in the sky to come to the same temperature and thus emit the same amount of microwave radiation.

They also insist that the so-called 'dark matter' and 'dark energy' are just more ad hoc 'fudge factors' designed to preserve the big bang theory:

Without some kind of dark matter, unlike any that we have observed on Earth despite 20 years of experiments, big-bang theory makes contradictory predictions for the density of matter in the universe. Inflation requires a density 20 times larger than that implied by big bang nucleosynthesis, the theory's explanation of the origin of the light elements. And without dark energy, the theory predicts that the universe is only about 8 billion years old, which is billions of years younger than the age of many stars in our galaxy.

They go on to add to these indictments, the observation that the big bang theory has not been able to provide a basis for quantitative predictions:

What is more, the big bang theory can boast of no quantitative predictions that have subsequently been validated by observation. The successes claimed by the theory's supporters consist of its ability to retrospectively fit observations with a steadily increasing array of adjustable parameters, just as the old Earth-centred cosmology of Ptolemy needed layer upon layer of epicycles.

However, it's the lack of funding for the support of non-standard research that they decry the most:

Supporters of the big bang theory may retort that these theories do not explain every cosmological observation. But that is scarcely surprising, as their development has been severely hampered by a complete lack of funding. Indeed, such questions and alternatives cannot even now be freely discussed and examined. An open exchange of ideas is lacking in most mainstream conferences. Whereas Richard Feynman could say that "science is the culture of doubt", in cosmology today doubt and dissent are not tolerated, and young scientists learn to remain silent if they have something negative to say about the standard big bang model. Those who doubt the big bang fear that saying so will cost them their funding.

Obviously, any question of a scientific nature ought to be answered on the basis of the known and established facts, as far as they can be discovered. There is no doubt that the standard model is the most firmly established cosmological model today, but how well it stands up to alternative, or non-standard models, must always depend on the strength of the challenger's merits. However, this is proving to be no small feat.

For instance, besides the cosmic background radiation (CBR), a non-standard cosmology must deal with the observation of cosmic redshift (ie., the apparent expansion of the universe.) Also, element distribution and "correlation functions" for the statistics of galactic distribution in the universe, are observations that the standard theory successfully addresses, and which big bang cosmologists insist that any non-standard model should be able to answer as well.

Redshift Anomalies

In the meantime, there are other issues that non-standard cosmologists insist must also be considered. A good example of these arguments is seen in the observations made since the 1960s by the astronomer Halton Arp, which offer an alternative to the standard interpretation of redshift and Hubble's Law. Arp claims that there are correlations between quasars and active galaxies that demonstrate that quasar redshift is not due to the expansion of the universe, but is instead local to the source of radiation (example: NGC 7603.) He has also uncovered evidence of discordant galaxy redshifts, and claims that there is a common theme between the discordant quasar and galaxy redshifts.

Arp has argued since the 1960's in his books "Quasar, Redshifts and Controversies", "Seeing Red", and many journals including ApJ, that some high-redshift quasars are directly connected to low-redshift galaxies via a low surface-brightness filament. He, along with other astronomers, also argued that the redshifts themselves are quantized. Arp and his colleagues assert these quantized redshifts cannot be explained by the standard model at macroscopic scales. Arp also believes that general relativity is possibly incorrect, and that one viable alternative might be LeSage gravity, although he does not use this idea as a major foundation in his "variable-mass hypothesis". A note on the variable-mass hypothesis: it is not Arp's alone, but a collaborative effort with Jayant Narlikar. Arp does believe that it is the most feasible explanation for his empirical observations.

Some astrophysicists believe that Arp's quasar/agn correlations do not exist in reality and that his observations are the result of faulty statistics. Many also believe that it is gravitational lensing that is responsible for most examples of quasars in the immediate vicinity of active galactic nuclei. Arp and others argue that if it is indeed gravitational lensing, then an explanation should be included in or derived from the standard cosmological model to account for the quasars' tendency to align along the host galaxies minor (rotational) axis.

Some non-standard cosmologists assert that these discordant redshifts contradict the foundations of the big bang, and that they can be accounted for in some non-standard models of cosmology. Many supporters of the standard cosmological model claim that these discordant redshifts are either not in contradiction with their foundations, or that the observations themselves might be faulty. As the model and the observations are in dispute, a concordance in observation would probably be a preliminary to resolving differences in theory.

While Arp attributes his observations to the "variable-mass hypothesis", its foundations lie within the frame of steady-state theory and Machian physics. Plasma cosmology is one non-standard model that may be able to account for Arp's empirical data, possibly without the need for the variable-mass. One main difference between plasma cosmology and steady-state is that plasma cosmology does not invoke matter creation; rather it invokes the flow of matter between different areas of the universe. In some versions of plasma cosmology, the matter is explicitly assumed to have always existed; but some variations allow that matter may have been created at some time in the past. Confirmation of the latter is currently beyond our empirical methods of investigation. The variable-mass theory instead invokes constant matter creation from active galactic nuclei, which puts it into the class of steady-state theory.

Accounting for Redshift Without the Big Bang

In some non-standard cosmology, the redshift is not regarded as a general expansion of space time, but rather as result of physical effects of ambiplasma (explainable via concepts in the Sunyaev Zeldovic Effect). Also, some non-standard cosmology may attribute the redshift to physical effects of photons or it may assert that the universe is expanding but that this expansion is not the result of space's expansion itself (i.e. the Alfven universe, wherein a local expansion may be possible due to matter annihilation or a double-layer release; see Plasma cosmology.)

The most radical, non-standard, cosmology by far is found in the Reciprocal System of Theory (RST), which explains the existence of matter in terms of a new definition of motion. In this cosmology, matter is cycled between two inverse sectors of the universe, entering the observable sector in the form of isotropic, high-energy cosmic rays, and exiting it via high-energy explosions in AGN. While the RST cosmological model is thus a steady-state model, accounting for CMB, element distribution, galactic distributions, clusters and large scale structure, among others, it explains all these on the basis of a universal expansion produced by a new, postulated universal motion, from which all else derives, including radiation, matter, gravity, etc. Hence, general relativity, big bang, inflation, nucleosynthesis, vacuum energy, in short, the entire collection of theories forming the standard cosmological model, is replaced whole cloth.

The general time dilation

One rather unobtrusive non-standard cosmology, an extension of Einsteinian gravitaton, is based on a contested for some time by cosmologists principle of conservation of energy. It turns out that if the principle of conservation of energy is valid then there must exist "general time dilation" a relativistic effect of slowing of the rate of time in any space containing dust.

This effect looks almost exactly as the hypothetical tired light effect except that it produces also an exponential time dilation and by that it is undistinguishable from an accelerating expansion of space.

Despite that the possibility of the effect is known at least since 1985 it isn't accepted as real because conservation of energy isn't accepted in cosmology and instead the expansion of space is accepted as real. Both effects can't coexist for observational reasons. Only either the principle of conservation of energy can be real or the expansion of the universe since there seems not to be enough cosmological redshift to satisfy both of them together.

If the principle of conservation of energy were valid though it would simulate accelerating expansion of space with Hubble's constant at observer , where G is Newtonian gravitational constant and ρ is density of space, or alternatively , where c is speed of light and R is Einstein's radius of the universe. It might also justify, providing a mechanism for large redshift in dense clouds of dust, the postulated by Halton Arp non cosmological origin of quasars.

The predicted numbers for testing the viability of the effect for our universe, assuming its density as , would be for the apparent expansion and for its apparent acceleration. The acceleration of the expansion is observed but its rate is not known precisely enough to base on it the vilability of the effect under discussion.

Dark matter and dark energy

During the 1970s and 1980s various observations (notably of galactic rotation curves) showed that there was not sufficient visible matter in the universe to account for the strength of gravitational forces within and between galaxies. This led to the idea that up to 90% of the matter in the universe is non-baryonic dark matter. While this idea was initially controversial, it is now a widely accepted part of standard cosmology. However, non-standard theories such as Modified Newtonian Dynamics (MOND) have been put forward as alternatives that do not require dark matter to explain the observations, but at the expense of modifying existing laws of gravity.

More recently (since 1997) observations of supernovae in the distant universe have suggested that a large part of the energy density of the universe consists of a repulsive dark energy (possibly simply "vacuum energy", but possibly something more complicated) which is causing the expansion of the universe to accelerate. While this conclusion has been rapidly accepted by most big bang, standard cosmologists, the explanation of the existence of dark matter and dark energy, now considered to be a major requirement that any successful cosmological model must meet, constitutes the single, most serious challenge to any of them, standard or not.

See also

Types: Ekpyrotic, Plasma cosmology, Reciprocal System of Theory, Steady state theory, Quasi steady state cosmology, Machian Cosmology
Related: Unsolved problems in physics, Solar neutrino problem, Dirac large numbers hypothesis, De Sitter universe
Creation: Creative evolution, Creation myths, Creationism
Other: Presocratic philosophers, Anthropic principle

Bibliography

External links and references

General

Informational Research articles [ed. full of technical language, but sometimes with introductions in plain English]