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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 "based on the wrong assumptions". However, a non-standard cosmology is not simply one that claims that the standard model is wrong. Many observational cosmology results and laboratory and space-based experimental results have brought a state of unrest to the foundations in the standard model. Non-standard cosmology is then the attempt to coherently address these issues from a framework which is not in contradiction to empirical observation and experiment, even though the foundations of the non-standard model might clearly contradict those of the standard model.
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2 Non-standard 3 Dark energy 4 See also 5 Bibliography 6 External links and references |
The standard model of cosmology has asserted that:
Standard model
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.
Besides the cosmic background radiation (CBR), another basic issue which a non-standard cosmology must deal with is 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 parts of the standard theory which cosmologists insist that any non-standard model should address.
Observations made since the 1960s by the astronomer Halton Arp can be used to disprove 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. He has clearly 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 - something that current theories cannot explain at macroscopic scales. He 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 feasable explanation for his empirical observations however.
Some astrophysicists (and in particular those that follow the standard model) 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 proposed by the standard community to account for the quasars' tendency to align along the host galaxies minor (rotational) axis.
Non-standard cosmologists tend to claim 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. However, as noted above, many standard cosmologists claim that these discordant redshifts are either not in contradiction with their foundations, or that the observations themselves are faulty. Those that claim no contradiction believe that they can account for these observations from within the big bang.
As already mentioned, Halton Arp attributes his observations to the "variable-mass hypothesis", whose foundations lie within the frame of steady-state theory and Machian physics. However, 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 (the matter is explicitly assumed to have always existed; but some variations of plasma cosmology allow that matter may have been created at some time in the past which is 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.
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.)
One example of a highly speculative and controversial idea that is considered a non-standard cosmology is the ekpyrotic universe which holds that the expansion of the universe began in the collision of two membranes from alternate dimensions. This is considered a non-standard cosmology because it argues against premises of the big bang model.
During the 1970s observations, data over the universe indicates that some energy in the universe is not visible, consisting of dark matter, dark energy, or just "vacuum energy". The exact nature of baryonic matter and this energy is being researched.
General
Non-standard
Dark energy
See also
Bibliography
External links and references
Informational
Research articles [ed. full of technical language, but sometimes with introductions in plain English]