I am now going to supply what looks to me like a good summary comparative analysis between the Big Bang model and Other Non-Conventional Models of the Universe:
Information of Big BangIn astrophysics, the term Big Bang is used both in a narrow sense to refer to the interval of time roughly 13.7 billion years ago when the photons observed in the microwave cosmic background radiation acquired their black-body form, and in a more general sense to refer to a hypothesized point in time when the observed expansion of the universe (Hubble's law) began. According to the Big Bang theory, the universe originated in an infinitely dense singularity. Space has expanded with the passage of time, objects being moved farther away from each other.
In
cosmology, the Big Bang theory is the prevailing scientific theory about the early development and shape of the universe. The central idea is that the observation that galaxies appear to be receding from each other can be combined with the theory of general relativity to extrapolate the conditions of the universe back in time. This leads to the conclusion that as one goes back in time, the universe becomes increasingly hot and dense.
There are a number of consequences to this view. One consequence is that the universe now is very different than the universe in the past or in the future. The Big Bang theory predicts that at some point, the matter in the universe was hot and dense enough to prevent light from flowing freely in space. That this period of the universe would be observable in the form of cosmic background radiation (CBR) was first predicted in the 1940s, and the discovery of such radiation in the
1960s swung most scientific opinion against the Big Bang theory's chief rival, the
steady state theory.
Using current physical theories to extrapolate the Hubble expansion of the universe backwards leads to a
gravitational singularity, at which all distances become zero and temperatures and pressures become infinite. What this means is unclear, and most physicists believe that this is because of our
limited understanding of the laws of physics with regard to this type of situation, and in particular, the lack of a theory of
quantum gravity.
There are actually many theories about the Big Bang. Some theories purport to explain the cause of the Big Bang itself, and as such have been criticized as being modern
creation myths. Some people believe that the Big Bang theory lends support to traditional views of creation, for example as given in
Genesis, while others believe that all Big Bang theories are inconsistent with such views. The relationship between religion and the Big Bang theory is discussed
below.
Overview
Based on measurements of the expansion of the universe using
type I supernovae, measurements of the lumpiness of the
cosmic microwave background, and measurements of the
correlation function of galaxies, it is currently believed that the universe has an age of
13.7 ? 0.2 billion years. The fact that these three separate measurements of completely different things are all consistent with each other is considered strong evidence for the model.
The universe as we know it was initially almost uniformly filled with energy and extremely hot. As the distances in the universe rapidly grew, the temperature dropped, leading to the creation of the known
forces of physics,
elementary particles, and eventually
hydrogen and
helium atoms in a process called
Big bang nucleosynthesis.
Over time, the slightly denser regions of the almost, but not quite, uniformly distributed matter were pulled together by
gravity into clumps, forming gas clouds,
stars,
galaxies, and the other astronomical structures seen today. The details of how the process of galaxy formation occurred depends on the type of matter in the universe, and the three competing pictures of how this occurred are based on the properties of three types of matter known as
cold dark matter,
hot dark matter, and
baryonic matter. These three models have been tested through computer simulations and observations of galactic
correlation functions. The best measurements available (from
WMAP) show that the dominant form of matter in the universe is in the form of
cold dark matter. The other two types of matter make up less than 20% of the matter in the universe.
It is at present unknown whether the
singularity of
spacetime described above is a physical reality or just a mathematical extrapolation of
general relativity beyond its limits of applicability. The resolution of this depends on a theory of
quantum gravity, which is not currently available. Nevertheless, there has been intense theoretical work on trying to figure out what happened before the Big Bang. Some of these efforts involve the
ekpyrotic universe, and there has also been interest in the
anthropic principle.
In general relativity, one usually talks about spacetime and cannot cleanly separate space from time. In the Big Bang theory, this difficulty does not arise;
Weyl's postulate is assumed and time can be unambiguously measured at any point as the "time since the Big Bang". Measurements in this system rely on so-called conformal distances and times which removes the expansion of the universe from consideration of spacetime measurements.
The Big Bang was not an explosion of matter moving outward to fill an empty universe; it is space itself that is expanding. So, bizarre as it may seem, the distance between any two fixed points in our universe is increasing. Intuitively this seems impossible: if the distance between two things increases then it seems that by definition one or both must be moving. But this is not so, as becomes clear if you consider the simplistic but logically equivalent model of a universe of constant size (whether finite or infinite), in which everything is shrinking. The people who live in this universe are shrinking too, as are all their scientific instruments. When these people measure the distance between two points that are sufficiently far apart, the distance will seem to be increasing, because the yardsticks they use to measure with are shrinking along with everything else. The fundamental assumption in this idea is that spacetime on the largest scales is unaffected by locality; objects that are bound together do not expand with spacetime's expansion because local forces keep them together. The expansion of the universe on local scales is so small that the difference of any local forces is unmeasurable by current techniques.
Because it is space itself that is expanding, and not a case of objects flying apart through space, the distance (in the sense of
comoving distance) between far removed galaxies can increase faster than the
speed of light without violating the laws of
special relativity.
Literatur:
Bye Bye Big Bang: Hello Reality [Authors: William C. Mitchell]Insightful and Thought-Provoking From old Omni magazine to current Scientific American and Discover magazines, books and online sources, I have watched Big Bang theory from the sidelines as it has developed over the years. Initially, it made sense, but as the years progressed, especially in the years after the Hubble Space Telescope opened the far heavens to us. I've read the articles, I've seen tweak after tweak over the years, claims of past ability to predict (such as the temperature of the m...
History of the theory
In
1927, the Belgian priest
Georges Lema?e was the first to propose that the universe began with the explosion of a "primeval atom". Earlier, in
1918, the
Strasbourg astronomer
Wirtz had measured a systematic
redshift of certain "
nebulae", and called this the
K-correction, but he wasn't aware of the cosmological implications, nor that the supposed nebulae were actually galaxies outside our own
Milky Way.
Einstein's theory of
general relativity developed during this time had the result that the universe could not remain static, a result that he himself considered wrong, and which he attempted to fix by adding a
cosmological constant which did not fix the problem. Applying general relativity to cosmology was done by
Alexander Friedmann whose equations describe the
Friedmann-Robertson-Walker universe.
In the 1930s,
Edwin Hubble found experimental evidence to help justify Lema?e's theory. Hubble had also determined that galaxies were receding back in 1913. Again using redshift measurements, Hubble determined that distant galaxies are receding in every direction at speeds (relative to the Earth) directly proportional to their distance, a fact now known as
Hubble's law.
Since galaxies were receding, this suggested two possibilities. One, advocated and developed by
George Gamow, was that the universe began a finite time in the past and has been expanding ever since. The other was
Fred Hoyle's
steady state model in which new matter would be created as the galaxies moved away from each other and that the universe at one point in time would look roughly like any other point in time. For a number of years the support for these two opposing theories was evenly divided.
In the intervening period however, all observational evidence gathered has provided overwhelming support for the Big Bang theory, and since the mid-
1960s it has been regarded as the best available theory of the origin and evolution of the cosmos, and virtually all theoretical work in cosmology involves extensions and refinements to the basic Big Bang theory. Much of the current work in cosmology includes understanding how galaxies form within the context of the Big Bang, understanding what happened at the Big Bang, and reconciling observations with the basic theory.
Huge advances in Big Bang cosmology were made in the late 1990s and the early 21st century as a result of major advances in
telescope technology in combination with large amounts of satellite data such as from
COBE and
WMAP. This data allowed astronomers to calculate many of the parameters of the Big Bang to new precision and opened up a major unexpected finding that the expansion of the universe appears to be
accelerating.
Over the decades a number of weaknesses have been identified in the Big Bang theory, but these have thus far all been addressed by extensions and refinements such as
cosmic inflation. As of
2003, there are no weaknesses in the Big Bang theory which are regarded as fatal by most or even a large minority of cosmologists. However, some cosmologists still support
non-standard cosmologies in which the Big Bang does not occur.
Recent research has been refining the Big Bang by including a model for the matter within the universe to understand the process of galaxy formation. Most current models are based on the notion of
cold dark matter which has supplanted other models of
hot dark matter and
baryonic matter. As of 2003, theories based on cold dark matter still have some conflicts with observations, namely the
Dwarf galaxy problem and the
cuspy halo problem.
See also:
Timeline of the Big BangSupporting evidence
In describing the evidence for the Big Bang, it is necessary to distinguish between observations which are also consistent with other theories, and observations which are not easily explained by other theories. The former category includes the observations that the universe appears to be isotropic, that galaxies appear to be receding from each other, and that the sky is dark (see Olbers's paradox). While these observations are all consistent with the Big Bang theory, each of them is also consistent with at least one other theory, such as Fred Hoyle's steady-state universe and Hannes Alfven's plasma universe.
The observations which are readily explained within the Big Bang framework but which are not so easily explained otherwise are as follows.
Cosmic background radiation
WMAP image of the cosmic background radiation
One feature of the Big Bang hypothesis was the prediction in the 1940s of the discovery of the cosmic microwave background radiation or CMBR. According to the Big Bang theory, as all the mass/energy of the universe emerged from a primordial explosion, the initial density of the universe must have been incredibly high. Since matter cools when it becomes less dense, the early universe must have been extremely hot. In fact, the temperature of the very early universe must have been so high that matter as we know it could not exist, because the subatomic particles would have been too energetic to aggregate into atoms.
However, as the temperature of the universe fell, the theory predicted that more familiar forms of matter would form from the
primordial plasma. At some stage (currently reckoned to be around 500,000 years after the beginning), the temperature would fall below 3000 K. Above this temperature, electrons and protons are separate, making the universe opaque to light. Below 3000 K, atoms form, allowing light to pass freely through the gas of the universe. This is known as photon decoupling.
The Big Bang theory therefore predicts that if you look far enough into space, and hence far enough back in time, you will eventually see the location at which the universe becomes opaque to radiation. The radiation from this region will be redshifted because of the Hubble expansion. This results in the visible spectrum of the 3000 kelvin radiation from the opaque region to be redshifted to a much lower temperature. The radiation should be almost completely isotropic.
At the time they were made and for the next 20 years, the predictions of the Big Bang theory regarding CMBR were largely ignored, simply because they remained unverifiable due to inadequate technology. Initially, George Gamow calculated that the CMBR should appear as a black body radiating at 50K. He later revised the calculation and estimated the temperature of the CMBR as about 5K. This was an error being somewhat higher than the 2.73K black body later observed.
In
1964,
Arno Penzias and
Robert Wilson conducted a series of diagnostic observations using a new
microwave receiver owned by
Bell Laboratories (which was designed for normal telephone communications) and accidentally discovered the cosmic background radiation originally predicted by Gamow. This observation was later confirmed by the Peebles group at
Princeton University, who were themselves trying to construct a microwave
antenna with a ruby
maser to detect the CMBR when Penzias and Wilson made their serendipitous discovery. It was not until Penzias and Wilson consulted with the Peebles group that they understood what it was they had detected. Penzias and Wilson published their findings jointly with the Peebles group in the
Astrophysical Journal.
Their discovery provided substantial confirmation of the general CMBR predictions (though it required correction of inaccurate values), and pitched the balance of opinion in favour of the Big Bang hypothesis. Penzias and Wilson were awarded the Nobel Prize for their discovery.
In
1989,
NASA launched the
Cosmic Background Explorer satellite (COBE), and the initial findings, released in 1990, were consistent with the Big Bang theory's predictions regarding CMBR, finding a local residual temperature of 2.726 K, determining that the CMBR was generally isotropic, and confirming the "haze" effect as distance increased. During the 1990s, CMBR data was studied further to see if small anisotropies predicted by the Big Bang theory would be observed. They were found in the late 1990s.
In early 2003 the results of the
Wilkinson Microwave Anisotropy satellite (WMAP) were analysed, giving the most accurate cosmological values we have to date. This satellite also disproved several specific inflationary models, but the results were consistent with the inflation theory in general.
Abundance of primordial elements
Using the Big Bang model it is possible to calculate the concentration of
helium-4, helium-3,
deuterium and
lithium-7 in the universe. All the abundances depend on a single parameter, the ratio of photons to
baryons. The abundances predicted are about 25 percent for 4 He, a 2 H/H ratio of about 10 -3 , a 3 He/H of about 10 -4 and a 7 Li/H abundance of about 10 -9 .
Measurements of primordial abundances for all four
isotopes are consistent with a unique value of that parameter (see
Big Bang nucleosynthesis), and the fact that the measured abundances are in the same range as the predicted ones is considered strong evidence for the Big Bang. There is no obvious reason outside of the Big Bang that, for example, the universe should have more helium than deuterium or more deuterium than 3 He. Thus far, no other theory has attempted to make the nucleosynthetic predictions that the Big Bang does.
Theories which assert that the universe has an infinite life such as the
steady state theory fail to account for the abundance of
deuterium in the cosmos, because deuterium easily undergoes
nuclear fusion in stars and there are no known astrophysical processes other than the Big Bang itself that can produce it in large quantities. Hence the fact that deuterium is not an extremely rare component of the universe suggests that the universe has a finite age.
Theories which assert that the universe has a finite life but that the Big Bang did not happen have problems with the abundance of
helium-4. The observed amount of 4 He is far larger than what could be created via stars or any other known process. By contrast, the abundance of 4 He are very insensitive to assumptions about baryon density changing only a few percent, as the baryon density changes by several orders of magnitude. The observed value of 4 He appears to be within the range calculated.
This having been said, there are three theoretical issues with Big Bang nucleosynthesis which have some potential of undermining the theory. The first is that the baryon concentration necessary to get an exact match with the current abundances is inconsistent with a universe with mostly baryons. The second is that the Big Bang predicts that no elements heavier than lithium would have been created in the Big Bang, yet elements heavier than lithium are observed in quasars, which presumably are some of the oldest galaxies in the universe. The third problem is since big bang nucleosynthesis produces no elements heavier than lithium, then we ought to see some long lived remnant stars which have no heavy elements in them. We don't.
The standard explanation for the first are that most of the universe isn't composed of baryons. This explanation fits nicely with other evidence of
dark matter such as galaxy rotation curves. The standard explanation for the second and third is that the universe underwent a period of massive star formation creating large high mass stars and that without heavy elements, forming low mass
red dwarf stars is impossible. This explanation has the feature that it predicts a class of stars that, as of 2004, have not been observed. Hence, in a few years we should have either seen them, which would support the big bang scenario, or we won't, in which case there is a possibility that we will have to fundamentally alter our views of the universe.
Galactic evolution and quasar distribution
One observation that has become increasingly apparent since the early 1970s is that while the universe appears to be isotropic in space (i.e. the universe in one direction looks very much like the universe in another direction) it is not uniform with respect to distance (due to the finite speed of light, greater distances represent earlier times in the past). As one looks to increasingly large distances, the universe looks very different. For example, there are no nearby
quasars, but there are many quasars once you pass a given redshift, and then the quasars disappear at a still further distance. Similarly, the types and distribution of galaxies appears to change markedly over time and once one passes a given distance, the number of galaxies fall off considerably.
Weaknesses and criticisms of the Big Bang theory
Throughout its history, a number of criticisms have been offered against the Big Bang theory. Some of them are today mainly of historical interest, and have been removed either through modifications to the theory or as the result of better observations. Others issues, such as the
cuspy halo problem and the
dwarf galaxy problem of
cold dark matter, are considered to be non-fatal as they can be addressed through relatively minor adjustments to the theory. Finally, there are proponents of
non-standard cosmologies who believe that there was no Big Bang at all.
The initial condition problem
One unanswered question is how the Big Bang might have occurred. The difficulty of answering this question lies with the absence of a theory of quantum gravity. As one goes back in time, the temperature and the pressures increase to the point where the physical laws governing the behavior of matter are unknown. It is hoped that as we understand these laws that we will better be able to answer the question of what happened "before" the Big Bang.
Magnetic monopole problem
The magnetic monopole problem was an objection that was raised in the late-1970s.
Grand unification theories predicted point defects in space which would manifest themselves as
magnetic monopoles, and the density of these monopoles was much higher than what could be accounted for. This problem is resolvable by the addition of
cosmic inflation.
The horizon problem
The horizon problem results from the premise that information cannot travel faster than light, and hence two regions of space which are expanding at faster than the speed of light relative to each other cannot communicate. This means that there is no mechanism to ensure that they have the same temperature. In the
1970s, no anisotropies had been observed which contradicted non-inflationary theories of the Big Bang. This problem was partially resolved by
cosmic inflation which reduced the horizon problem by arguing that the early universe suddenly underwent a period of massive expansion before which regions that would later not be in contact with each other could equalize their temperatures.
However, cosmic inflation predicted that the anisotropies in the Big Bang would be reduced but not eliminated. Even with inflation, there would be regions of space that could not be in thermal contact. In the early
1990s, there was some excitement and nervousness, as satellite detectors such as
COBE at first failed to detect any anisotropy, and various inflationary scenarios began to be invalidated. Had another few years passed without any detections of anisotropy, the Big Bang would have been very badly hurt, but this was not the case, and the expected anisotropies were detected.
The horizon problem is still of major interest because it allows one to deduce large amounts of information from the CMB. Different expansion rates will result in different amounts of lumpiness in the CMB as a result of material falling past the horizons at different times, and this provides much data about the conditions within the universe at the time the CMB was formed.
Globular cluster age
One major issue that had the potential of challenging the Big Bang occurred in the mid-1990s. Computer simulations of globular clusters suggested that they were about 15 billion years old, which conflicted with some values of the Hubble constant suggesting that the universe was 10 billion years old. This issue was resolved in the late 1990s with other new computer simulations which included the effects of mass loss due to stellar winds indicated a much younger age for globular clusters.
Elemental abundance arguments
During the mid-1990s, measurements of the amount of primordial helium abundance suggested the possibility that the helium abundance of the first stars would have been less than 20%. If this were the case, it would have posed major problems for the Big Bang theory, as it is very difficult to get low amounts of helium from the Big Bang. This potential problem was resolved in the late-1990s by better measurements of helium abundances.
As mentioned earlier, there are also issues with the baryon density and the observation of heavy elements with quasars. These are widely considered to be less serious challenges to the Big Bang, however, they have the potential to undermine the theory if explanations advanced for them prove inadequate.
For example, the consensus is that in order to explain heavy elements in quasars, a large burst of massive star formation is needed, and as of 2004, much current research is aimed at trying to find these stars. If these
population III stars are found, this will strengthen the Big Bang theory.
Redshift
There also remain small numbers of astrophysicists, including
Y.P. Varshni and
Halton Arp, who argue that redshifts in galaxies are not strictly due to the Doppler effect, and that this invalidates the need for the Big Bang. However, these astrophysicists propose no alternative mechanism, rather they rely on their own incredulity to criticize the standard cosmological model.
Dark matterDuring the 1970s, observations were made that - assuming that all of the matter within the universe could be seen - created problems for the Big Bang theory, as it seemed to underestimate the amount of deuterium in the universe and lead to a universe that was much more "lumpy" than observed. These problems are resolved if one assumes that most of the matter in the universe is not visible, and this assumption seems to be consistent with observations that suggest that much of the universe consists of dark matter.
The effects that dark matter has on Big Bang calculations generally do not depend on the detailed properties of the dark matter. The main property of dark matter which influences cosmology is whether the dark matter consists of particles that are heavy and hence are moving slowly, thereby creating
cold dark matter, or whether it consists of particles that are light and hence are moving quickly, thereby creating
hot dark matter, or whether the dark matter consists of ordinary matter which is
baryonic matter.
The future according to the Big Bang theory
All the matter in the universe is gravitationally attracted to other matter which is within the observable horizon (defined by the age of the universe). This should cause the expansion rate of the universe to slow down over time. Exactly how much matter exists in any given volume, relative to how large the horizon is and how fast the universe is currently expanding can lead to one of three scenarios:
The
Big CrunchIf the gravitational attraction of all the matter in the observable horizon is high enough, then it could stop the expansion of the universe, and then reverse it. The universe would then contract, in about the same time as the expansion took. Eventually, all matter and energy would be compressed back into a gravitational singularity. There are theories about what happens after this, but these remain uncertain as the physics of singularities remains in question. Also, the omega point theory suggests that an infinite amount of computational capacity might be available in the finite time before the Crunch.
The Big Freeze
If the gravitational attraction of all the matter in the observable horizon is low enough, then the expansion will never stop. As the matter disperses into ever greater and greater volumes, new star formation would drop off. The average temperature of the Universe would asymptotically approach
absolute zero, and the Universe would become very still and quiet. Eventually, all the
protons would decay, the black holes would evaporate, and the Universe would consist of dispersed subatomic particles. The Big Freeze is also known as the
heat death of the universe.
Balance
If the gravitational attraction of all the matter in the observable horizon is just right, then the expansion of the universe will asymptotically approach zero. The temperature of the universe would asymptotically approach a stable value slightly above absolute zero. Entropy would increase, and the end result (with protons decaying) would be similar to the Big Freeze.
Recent observations
One extremely puzzling recent discovery comes from observations of
type I supernovae which allow one to better calculate the distance to galaxies, from observations of the cosmic microwave background, from gravitational lensing, and from the use of large length scale statistics of the distributions of galaxies and quasars as standard rulers for measuring distances. It appears that the expansion of the universe is accelerating, an observation which astrophysicists are currently trying to understand (see
accelerating universe). The currently favored approach is to reintroduce a non-zero
cosmological constant into
Einstein's equations of General Relativity, and adjust the numerical value of that constant to match the observed acceleration. This is akin to postulating a repelling "dark energy", also called
quintessence.
See also the
ultimate fate of the Universe.
Big Bang theory and religion
When the Big Bang theory was originally proposed, it was rejected by most cosmologists and enthusiastically embraced by the
Pope, because it seemed to point to a creation event. A few scientists, for example astronomer
Robert Jastrow, also see the Big Bang as confirmation of the account given in Genesis. While most scientists nowadays view the Big Bang theory as the best explanation of the available evidence, and the
Catholic Church still accepts it, some conservative
Christians (usually
Fundamentalists) oppose it because the age of the universe is far higher than the one calculated from a literal reading of the book of
Genesis in the
Bible. Many ways have been proposed to reconcile the two including denying the fundamentalist reading of Genesis or denying the correctness of the age of the universe - see
Day-Age Creationism.
Similarly, some Muslims claim that a verse in the
Qur'an, the holy book of
Islam, can be correlated to the Big Bang. The verse in question, the 30th in its 21st chapter, states the following:
"Do the disbelievers not see that the heavens and the earth were joined together, then I split them apart". Origin of the term
The term "Big Bang" was coined in
1949 by
Fred Hoyle during a
BBC radio program,
The Nature of Things; the text was published in 1950. Hoyle did not subscribe to the theory and intended to mock the concept. It may have been in part a joking reference to the fact that George Gamow, the leading proponent of the theory at the time, also worked on the development of the
atomic bomb.
See also
Main:
Timeline of the Big Bang |
Dark Ages |
Big bounce |
Big Crunch (
Heat-death of the Universe and
Oscillatory Universe) |
Big Rip |
Big bang nucleosynthesis |
Gravitational singularity |
Cosmic inflation |
Cosmic variance |
De Sitter universe Creation:
creation myths |
Creation belief |
Creationism |
Dating Creation |
Young Earth Creationism Cosmology and
Astrophysics:
A Brief History of Time |
Beyond the standard Big Bang model |
Cosmological arguments |
Estimates of the date of Creation |
Galaxy formation and evolution |
Non-standard cosmology (
Creative evolution,
Ekpyrotic,
Plasma cosmology,
Steady state theory) |
Magnitude order |
Primordial black hole |
Primordial helium abundance |
Stellar population |
Timeline of cosmology |
Theoretical astrophysics |
Ultimate fate of the Universe Astronomy:
History of astronomy |
CMBR Timeline |
Gamma-ray Large Area Space Telescope |
Massive compact halo object |
Red dwarf |
Shape of the universe |
Solar nebula |
Stars |
Supermassive black hole |
Universe (
Large-scale structure of the cosmos)
People: Hannes Alfv?/a>
| Albert Einstein | [[
George Gamow]] |
Fred Hoyle |
Georges Lema?e |
Peter Lynds |
Arno Allan Penzias |
Gerald Schroeder |
Janez Strnad |
Robert Woodrow Wilson List of physics topics:
Arrow of time |
Electronuclear force |
Comoving distance |
Compton effect |
Dark energy |
Dark matter (
Cold dark matter and
Hot dark matter) |
Hubble's law |
Integrated Sachs Wolfe effect |
Magnetic monopole |
Observation |
Olbers' paradox |
Phase transition |
Quantum gravity |
Redshift |
Theory of everything |
Triple-alpha process |
Weyl's postulate Things:
Ambiplasma |
Antimatter |
Axion |
Background radiation |
Cosmic light horizon |
Cosmic microwave background |
Fireball |
Far Ultraviolet Spectroscopic Explorer (FUSE)
Atomic Chemical Elements :
Beryllium |
Carbon |
Chemical abundance |
Deuterium |
Helium |
Ylem Lists:
List of astronomical topics |
List of famous experiments |
List of time periods |
Timeline of the Universe Other:
Bang |
Discworld |
Galactus |
Horrendous Space Kablooie External links and references
General
Smithsonian Institution, "
UNIVERSE! - Beyond the Big Bang: Briefing Room (http://cfa-www.harvard.edu/seuforum/explore/bigbang/briefing.htm)".
PBS.org, "From the Big Bang to the End of the Universe. The Mysteries of Deep Space Timeline (http://www.pbs.org/deepspace/timeline/)" D'Agnese, Joseph, "The last Big Bang man left standing, physicist Ralph Alpher devised Big Bang Theory of universe (http://www.findarticles.com/cf_dls/m1511/7_20/55030837/p1/article.jhtml)". Discover, July, 1999. Google Research articles
These are generally full of technical language, but sometimes with introductions in plain English.
Analysis
February 18,
2001.
Whitehouse, David, "Before the Big Bang (http://news.bbc.co.uk/1/hi/sci/tech/1270726.stm)". BBC News.
April 10,
2001.
Marmet, Paul, "Big Bang Cosmology Meets an Astronomical Death (http://www.newtonphysics.on.ca/BIGBANG/Bigbang.html)". Klempner, Geoffrey, "The ten big questions. Big Bang Theory (http://www.123infinity.com/big_bang_theory.html)" CosmologyStatement.org (http://cosmologystatement.org) Information of Non-standard cosmology - The neutrality of this article is disputed. See the article's talk page for more information.
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 microwave background radiation (CMB) in 1965 by Penzias and Wilson. These observations, combined with the theory of big bang nucleosynthesis and other evidence which suggested that the universe evolved, caused most cosmologists to favor the Big Bang theory over the steady state theory. Since around this time, in practice a non-standard cosmology has primarily meant any cosmological theory which questions the fundamental propositions of the Big Bang theory.
The motivation behind much of non-standard cosmology is the fact that to explain current observations within the framework of the big bang, one must include some seemingly ad-hoc assumptions and inelegant additions. For example, in order to make the big bang consistent with current observations, one would need to postulate the existence of some form of
dark matter and
dark energy and a phase of rapid expansion known as
cosmic inflation. Proponents of non-standard cosmologies argue that these additions to the theory lead to an inelegant system which some have compared to the Ptolematic model of the solar system. By investigating and questioning the basic assumptions of the Big Bang theory, non-standard cosmologies attempt to address these issues from a supposedly empirical framework, even though the foundations of non-standard models might clearly contradict those of the Big Bang theory.
One point that should be noted is that there is not a single non-standard cosmology. Within the category are many different models which often contradict each other. This is in contrast to standard model of cosmology that is designed to be in concordance with the sum total of all cosmological observations (see Lambda-CDM model). While what is considered the standard model of cosmology as opposed to a standard model of cosmology has changed over the years, the general consensus in the scientific community is that with the advent of precision cosmology, model-making in the field is today more of a parameter fitting exercize rather than complete reinvention. Non-standard cosmologies are promoted by a few generally independent researchers and amateurs who disagree with foundational assumptions and so reject the idea of applying concordance criteria to their models.
In addition, the term standard can be slightly misleading. For example, it is the case that all of standard cosmologies under serious consideration in 2004 contain physics which is outside the realm of the
standard model of particle physics and presume the existence of some form of particle, field, or object that has not been observed. Conversely, proponents of some non-standard cosmologies assert that their models contain no physics which has not been observed, and in fact often cite this fact as evidence in favor of their models.
Although most astronomers since the 1960s have concluded that observations are best explained by a variation of the big bang model, there have been two periods in which interest in non-standard cosmology increased due to observational data which posed difficulties for the big bang. The first occurred in the late 1970s when there were a number of unsolved problems such as the
horizon problem, the flatness problem, and the lack of
magnetic monopoles which challenged the models of the big bang then under consideration. These issues were eventually resolved by
cosmic inflation in the 1980s which subsequently became part of all future standard cosmologies. The second occurred in the mid-1990s when observations of the ages of
globular clusters and the primordial
helium abundance showed the potential of seriously challenging the big bang. However by the late 1990s, most astronomers had concluded that these observations did not challenge the big bang and in addition data from
COBE and
WMAP provided detailed quantitative data which was consistent with standard cosmologies.
Standard Models
The standard cosmologies have asserted that:
- redshifts observed in distant galaxies are due to the expansion of the universe
- this expansion is due to the expansion of space as predicted by
general relativity Non-standard cosmologies minimally challenge one or both of these, usually asserting that one or the other is incorrect.
Alternative models of cosmology that do not challenge the two assertions above are generally lumped together as standard cosmological models, even if they are not universally accepted. For example, the ekpyrotic universe 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 detractor of, the big bang theory.
Objections to the Standard Models
There are a number of general objections to the standard models which have been advanced by supporters of non-standard cosmologies, at one time or another. In addition there are specific objections to the Big Bang. One is that the Big Bang pre-supposes a beginning to the universe and fails to answer the question of what happened before the beginning. This point is considered to be moot by most standard cosmologists, since extrapolation of the universe's behavior before the
Planck time is considered to be as yet an unknown area of physics. Whether the
Big Bang predicts a singular beginning or an alternative universe without a beginning is not something that current theories of physics can answer for certain. Another objection is that the Big Bang requires esoteric and ad-hoc physics to explain observations. However this last point is not very strong, as even the non-standard cosmologies often employ what could be considered exotic physics to some. Many proponents of standard cosmologies do not deny that problematic issues exist in standard cosmologies. However, they argue that standard cosmologies based on the
Big Bang theory are better able to explain these issues than non-standard cosmologies.
With the advent of space-based instruments, along with improved ground-based instruments, we have gained a broader view of the electro-magnetic spectrum during the late 20th century. We are now able to detect frequencies of radiation that where not accessible during the primary period that the Big Bang theory took shape. With each new instrument comes new observations of astrophysical process. In some cases there have been observations which the Big Bang theory does not appear to explain well. However, these observations are handled within the standard models by making refinements and enhancements to the basic Big Bang theory, and so the list of observations which most cosmologists feel are unexplained, changes over time.
Supporters of non-standard cosmologies claim that these modifications and enhancements to the Big Bang theory are ad-hoc and incoherent, and have produced an overly complex and inelegant theory. For instance, it is generally agreed by astronomers that the big bang model simply cannot agree with observations without assuming the existence of
cosmic inflation which in turn requires the existence of
vacuum energy. In addition, it is also agreed that without assuming
dark matter that
big bang nucleosynthesis produces a massive underabundance of
deuterium, and that without assuming
dark energy that the big bang massively underestimates the age of the universe.
In an 'Open Letter to the Scientific Coummunity,' signed by thirty-three scientists around the world, including Hermann Bondi, and published in the May 22nd 2004 issue of the
New Scientist periodical, they protest that: 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.
For the most part, the accusation of the ad-hoc nature of the Big Bang theory is rejected by standard cosmologists. The observational evidence for inflation, dark matter, and dark energy comes in many different forms from a variety of independent observations. That these indepedent observations are in concordance with each other and that parameter space likelihood analysis shows no mutually exclusive regions makes the claim that the
Lambda-CDM model is ad hoc highly dubious. In addition most cosmologists react very strongly against charges that nonstandard cosmologies are being surpressed for ideological reasons and point out that developing a theoretical model of non-standard cosmology requires no particular large amount of funding, and while observational cosmology does require a great deal of funding and telescope time, the major observational cosmology projects such as
COBE,
WMAP, and the massive
galaxy surveys do not assume the correctness of standard cosmologies.
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 alternative's merits in comparison with those of the standard model.
For instance, besides the cosmic microwave background radiation (CMB), 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/theory that the standard model successfully addresses, and which big bang cosmologists insist that any non-standard model should be able to answer as well.
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 apparent strength of gravitational forces within and between galaxies. Since only gravitational forces are taken into account within the standard model, this led to the idea that up to 90% of the matter in the universe is non-
baryonic dark matter. In addition, assuming that the universe was mostly regular matter led to predictions that were strongly inconsistent with observations. In particular, the universe is far less lumpy and contains far less deuterium than can be accounted for without dark matter. While this idea was initially controversial, it is now a widely accepted part of standard cosmology due to observations in the anisotropies in the CMB, gravitational lensing studies, and x-ray measurements from galaxy clusters.
However, quasi steady-state theory and plasma cosmology have been put forward as alternatives that do not require dark matter to explain the observations of galactic curves. In some versions of plasma cosmology, for instance, the observed galaxy rotation curves are accounted for by the additional electro-magnetic forces and interactions. By treating the arms of galaxies as plasma filaments interacting with electromagnetic fields, the filamentary structure of galaxy clusters and superclusters can be viewed as a result of the self-amplifying nature of currents in plasmas. In this way, plasma cosmology proports to explain two observations often attributed in the standard cosmological models as due to dark matter. However, proponents of the Big Bang theory claim that there has not been offered any non-standard cosmology which explains in detail the
totality of proposed evidence for dark matter.
While it is true that in astrophysics plasma and magnetic effects are considered very important in determining the structure of gas and dust within a galaxy, it is unclear by what mechanism magnetic fields would change galaxy rotation curves and velocity dispersions. Galaxy velocity dispersion measurement come in part from observations of halo stars and it is unclear how a magnetic field would change the orbital motion of a star in an area where there is very little gas and dust. Furthermore the structure of the filaments seen in cosmological
galaxy surveys are very different than the structure of filaments seen in most plasma processes, and there is no proposed mechanism offered by the alternative model as to why the size of the structures has an upper-limit.
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 (perhaps simply "
vacuum energy", but possibly something more complicated) which is causing the expansion of the universe to accelerate. This conclusion has been accepted by most standard cosmologists since it matches the predictions that can be obtained for this effect from completely independent observations of the anisotropies in the CMB. An explanation of the proposed existence of dark matter and dark energy is required in order for any cosmological model to be successfull. Advocates of non-standard models claim there is no need to invoke dark matter or dark energy as gravity is not taken to be the only acting force in the universe.
Cosmic Microwave Background
Any cosmological theory should be able to explain the near-isotropy of the CMB (Cosmic Microwave Background) and should also be able to explain the micro-Kelvin CMB anisotropies measured in detail by the WMAP mission. Standard models invoke a period of inflation in the early universe, the underlying mechanism, although efforts to associate that period of inflation with a specific physical mechanism have been unfruitful.
Alfven, Lerner and others working within plasma cosmology have claimed that the temperature, isotropy, and non-polarisation of the CMB can be readily explained as the diffusion of galactic radio emission by the magnetic fields of intervening plasma filaments. Electrons travelling along the large, weak magnetic field lines of a galaxy can absorb radio, and re-emit it in a different direction. This scatters the radiation, much as light from the sun is scattered in a dense fog. This can also explain the observed decrease in radio brightness of galaxies relative to their IR luminosity with increasing redshift. Lerner explains that radiation from distant galaxies successively interacts with the magnetic fields of many intervening galaxies, nebulae, supernova remnants and so on, resulting in an isotropic scatter. What Lerner fails to explain is why the electrons should reemit in the best measured
blackbody spectrum observed in all of science and how the entire plasma can become thermalized with anisotropic radiation fields.
Standard cosmologists also calculate the anisotropies in the CMB and identify a number of features such as peaks and valleys in its power spectrum which correspond to cosmological quantities. WMAP has been especially fruitful in providing a goldmine of data that is interpreted easily by the standard cosmological models. The inability thus far of plasma cosmologies to come up with a theory that replicates these features in detail has led most astrophysicists to dismiss them. There was recently some excitement on the part of certain plasma cosmology adherents over an analysis of WMAP results by researchers at the University of Durham. This analysis proported to show certain micro-Kelvin anisotropies in the WMAP data correspond to the locations of local galactic clusters and superclusters. This association was just as predicted by the Sunyaev-Zeldovich effect and was the purpose of the investigation. However, some fans of Eric Lerner claim that his model predicted similar types of associations.
A second alternative explanation, favoured by Steady State theorists, is that the intergalactic medium contains microscopic iron dust particles or
whiskers, which can also scatter radio in the same manner to produce an isotropic CMB. However, observational evidence for the existence of these iron particles is yet to appear.
Either of these explanations could potentially free other alternative cosmological models such as general time dilation, steady state models, and so on from the need to explain the isotropy of the CMB, because they transform it into a local effect rather than a cosmological feature.
Redshift, AGN, and Quasars
In the meantime, there are other issues that some non-standard cosmologists insist must also be considered. A good example is the observations made since the 1960s by the astronomer
Halton Arp, which offer an alternative to the standard interpretation of quasar formation,
redshift and
Hubble's Law.
Arp has observed a handful of correlations between
quasars (and more recently,
X-ray sources from
Chandra data) and AGN (
Active Galactic Nuclei) which he claims demonstrates that quasar redshifts are not entirely due to the expansion of the universe, but contain a local, or
non-cosmological, component. Arp claims that clusters of quasars have been observed around many galaxies (examples include
NGC 3516 (
http://www.haltonarp.com/?Page=Images&Image=4) and
NGC 5985 (
http://www.haltonarp.com/?Page=Images&Image=5) as well as M51, NGC 7603, NGC 3370, NGC 4319, NGC 4235, NGC 4258) which all have some properties in common:
- The active galaxy always has a lower redshift than any of its associated quasars.
- The quasars tend to lie within a narrow conical zone centered about the minor (rotational) axis of the associated active galaxy.
- Schematically, the quasars' redshifts are inversely proportional to their angular distances from the AGN, i.e. as apparent distance from the AGN increases, the redshift of the quasars decrease.
- Some of the quasars occur as pairs on either side of an AGN, particularly the X-ray sources appearing in the Chandra data.
Some astrophysicists believe that
gravitational lensing might responsible for some examples of quasars in the immediate vicinity of AGN, but Arp and others argue that gravitational lensing cannot account for the quasars' tendency to align along the host galaxies minor axis.
These observations indicate to Arp that a relationship may exist between quasars (or at least a certain type of quasar) and AGN. Arp claims that these quasars originate as very high redshift objects ejected from the nuclei of active galaxies, and gradually lose their non-cosmological redshift component as they evolve into galaxies.
The biggest problem with this analysis is that today there are tens of thousands of quasars with known redshifts discovered by various sky surveys. The vast majority of these quasars are not correlated in any way with nearby AGN. Indeed, with improved observing techniques, a number of host galaxies have been observed around quasars which indicates that those quasars at least really are at cosmological distances and are not the kind of objects Arp proposes. Arp's analysis, according to most scientists, suffers from being based on small number statistics and hunting for peculiar coincidences and odd associations. In a vast universe such as our own, peculiarities and oddities are bound to appear if one looks in enough places. Unbiased samples of sources, taken from numerous
galaxy surveys of the sky show none of the proposed 'irregularities' nor any statistically significant correlations that Arp suggests exist.
In fact, the question of whether quasars are cosmological or not was an active controversy in the late 1960s and early 1970s, but by the late 1970s most astronomers had considered the issue settled. The main argument against cosmological distances for
quasars was that the energy required was far too high to be explainable by
nuclear fusion, but this objection was removed by the proposal of gravity powered
accretion disks.
In addition, it is not clear what mechanism would be responsible for such high initial redshifts, or indeed its gradual dissipation over time as the quasar evolves. It is also unclear why objects ejected from a galaxy should never seem to produce a blue shift. Moreover it is unclear how nearby quasars would explain some features in the spectrum of quasars which the standard model easily explains. In the standard cosmology, the clouds of neutral hydrogen between the quasar and the earth at different red shifts spikes between the quasar redshift and the rest frequency of Lyman alpha in a feature known as the
Lyman-alpha forest. Moreover, in extreme quasars one can observe the absorbion of neutral hydrogen which has not yet been reionized in a feature known as the
Gunn-Peterson trough. Most cosmologists see this missing theoretical work as sufficient reason to ignore the observations as either chance or error. Arp himself proposes Narlikar's variable mass hypothesis, which contains alternative explanations of various observed cosmological features, but it remains, at best, incomplete.
A consequence of Arp's proposed AGN-origin of quasars would be that quasars would be much closer, much larger, and much less luminous than currently supposed and their heavy element composition would no longer require primaeval
Population III stars. Such a theory would predict that the heavy element composition of quasars would be similar to the associated AGN, though observed metal lines in quasars are notoriously weaker than AGN. Variable luminosity and absorption phenomena such as the
Lyman-alpha forest would both be explained by as yet theoretically undeveloped "local means".
A further anomaly comes from the magnitude-redshift relation first discovered by Hubble. Plotting absolute galactic magnitudes against their redshift produces a clear linear relation, which in 1929 led Hubble to propose an expanding universe and
Fritz Zwicky to propose the
tired light hypothesis. However, quasars were discovered much later, and the same plot done using quasar data produces a much more diffuse scatter with no such clear linear relation. However, since the absolute magnitudes can only be calibrated using a size constraints from variability and an Eddington luminosity limit, it is likely that quasars are exhibbiting differing absolute luminosities that cannot neccessarily be derived from such simplistic first principles. Arp, Burbidge, and others maintain that the scatter in these plots further supports the idea that quasars have a
non-cosmological component to their redshift, but nearly everyone else in the field accepts that quasars have variable luminosity.
Non-standard Models
There have been a number of non-standard models which have been proposed.
Quasi Steady State Models
ADD MORE HERE
Although the original
steady state model is now considered to be contrary to observations even by its originators, a modification of the steady state model has been proposed which envisions the universe as originating through many little bangs rather than one big bang.
Tired Light Models
The
tired light effect was proposed by
Fritz Zwicky in 1929 to explain the observed
cosmological redshift. It has been found incompatible with the observed
time dilation that is associated with the cosmological redshift. In 1985 it was found that this incompatibility is removed if energy is strictly conserved since then the Einsteinian gravitation simulates exactly the tired light effect together with the associated time dilation. However, conservation of coordinate energy cannot reproduce the isotropic blackbody spectrum observed for the
Cosmic Microwave Background.
Plasma Cosmology VS Steady State
Halton Arp attributes his observations to the "variable-mass hypothesis", which has its foundations 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 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, matter is explicitly assumed to have always existed. However, it is noted that matter may have been created at some time in the past, but that confirmation of this is currently and may forever be beyond our empirical methods of investigation. In contrast with plasma cosmology, the variable-mass theory instead invokes constant matter creation from active galactic nuclei, which puts it into the class of steady-state theory.
The general time dilation
One rather unobtrusive non-standard cosmology, an extension of Einsteinian gravitaton, is based on a
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, an effect of exponential with distance from the observer slowing of the rate of time.
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 across macroscopic coordinates (known in physics simply as
the principle of conservation of energy) isn't accepted in cosmology. Instead the expansion of space is accepted as real. Both effects can't coexist for observational reasons as there doesn't seem to be enough Hubble redshift to satisfy both.
Generally the violation of the coordinate conservation of energy is accepted as required in standard cosmologies because in general the energy densities are frame dependent. Incidentally it doesn't hurt the principle of coordinate conservation of energy in all the rest of physics. Standard cosmologies are the only physical theories that can't accept the strict coordinate conservation of energy. In this aspect they present a non-trivial physics that allows creation of energy from nothing.
Allowing for general time dilation effectively recasts the
stress-energy tensor in
Einstein's Field Equations which non-trivially effects the
curvature of spacetime. This would have the effect of giving up the
Riemannian geometry as the geometry of spacetime and it would require to replace it with
Finsler geometry. It would require to drop the condition of symmetry of metric tensor. Einstein postulated dropping this condition in his "
On the General Theory of Gravitation" (
Scientific American, April 1950).
General time dilation doesn't explain features of the
Cosmic Microwave Background therefore an additional explanation would be needed to reproduce an isotropic radiation field that approximates a blackbody of temperature 2.73 K to the level of one part in one hundred thousand. Also an additional explanation of the abundances of light elements would be required if the principle of coordinate conservation of energy were accepted also in cosmology.
If this principle were valid though it would simulate accelerating expansion of space with Hubble's constant at observer
H 0 =
c /
R , 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
km /
s /
Mpc for the apparent expansion and
See also
- Types:
Ekpyrotic,
Plasma cosmology,
Steady state theory, Quasi steady state cosmology, Machian Cosmology
Related: Unsolved problems in physics, Solar neutrino problem, Dirac large numbers hypothesis, De Sitter universeCreation: Creative evolution,
Creation myths,
CreationismOther: Presocratic philosophers,
Anthropic principle Bibliography
- Narlikar, Jayant Vishnu, "Introduction to Cosmology". Jones & Bartlett Pub. January 1983. IUCAA. ISBN 0867200154
- Lerner. Eric J., "Big Bang Never Happened", Vintage Books, October 1992. ISBN 067974049X
- Mitchell, William C., "Bye Bye Big Bang: Hello Reality". Cosmic Sense Books. January 2002. ISBN 0964318814
- Hoyle, Fred, and Geoffrey Burbidge, and Jayant V. Narlikar, "A Different Approach to Cosmology : From a Static Universe through the Big Bang towards Reality". Cambridge University Press. February 17, 2000. ISBN 0521662230
- Hannes, Alfven D., "Cosmic Plasma". Reidel Pub Co., February 1981. ISBN 9027711518
- Peratt, Anthony L., "Physics of the Plasma Universe". Springer-Verlag, 1991, ISBN 0387975756
- Arp, Halton, "Seeing Red". Apeiron, Montreal. August 1998. ISBN 0968368905
External links and references
General
Annual Review of Astronomy and Astrophysics, Vol. 39, p. 211-248 (2001).
Lerner, E. J. "Radio absorption by the intergalactic medium." ApJ 361 (1990), 63-68. Klempner, Geoffrey, "The ten big questions. Big Bang Theory (http://www.123infinity.com/big_bang_theory.html)" Marmet, Paul, "Big Bang Cosmology Meets an Astronomical Death (http://www.newtonphysics.on.ca/BIGBANG/Bigbang.html)". Whitehouse, David, "Before the Big Bang (http://news.bbc.co.uk/1/hi/sci/tech/1270726.stm)". BBC News. April 10, 2001. Rosania, Gustavo, "AntiBigBang.com (http://antibigbang.com/) Come Discover The New Cosmology"! Jastrzebski, W. Jim, "The General Time Dilation (http://www.geocities.com/wlodekj/sci/3263.htm) Einsteinian reason for illusion of accelerating expansion of space" Informational
ArXiv)
Google Research articles [ed. full of technical language, but sometimes with introductions in plain English]
University of California, San Diego. Center for Astrophysics and Space Sciences and Department of Physics La Jolla, CA. [
aXvir.org : astro-ph/0108051]
Lopez-Corredoira, Martin, "Observational Cosmology: caveats and open questions in the standard model (http://arxiv.org/abs/astro-ph/0310214.)". Astronomisches Institut der Universit?Basel. [
aXvir.org : astro-ph/0310214] (part of "
Recent Research Developments in Astronomy & Astrophysics")
There's more that we don't know about the Universe then we can comprehend. Things like how 60% of the matter in the universe is called dark matter because no one knows what it is.
Putting the square peg in the round hole, quantum mechanic stuff.
