Dark matter

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DarkMatterNASA1.jpg
Dark matter, in astronomy, is any hypothetical matter[1] that astronomers infer when the actual mass of any observed celestial object is not sufficient to account for an observed gravitational effect.[note 1] It is one of two concepts (the other is dark energy) that evolutionistic astronomers invoke to account for observations that old-universe cosmologies, including the Big Bang, cannot explain. The term was introduced by Swiss astronomer Fritz Zwicky who hypothesized that it must be the gravity of unseen dark matter that holds fast moving galaxies together in clusters.[2][3]

Nowadays there is an ongoing controversy taking place about the detectability status of Dark Matter. While proponents of the Friedmann Big Bang cosmologies supplied several papers (the most recent one (2012) published in journal Nature[4][5]) making bold claims that the Dark Matter has been 'directly' observed or detected [note 2], their opponents including J.Hartnett however express their strong reservations and suggest that it "seems to be stretching things a bit, to put it mildly, given the many assumptions and interpretations necessarily involved". According to J.Hartnett the very essence of the ‘dark matter’ concept is that we have no explanation for what we observe and the whole dark matter scenario is in his view the result of incorrect physics being applied to the dynamics of astronomical bodies requiring ad hoc assumptions to be introduced to the norm. As an alternative explanation based on applying Occam’s razor for phenomena leading to dark matter hypothesis is proposed a new theory by late Israeli cosmologist/physicist Moshe Carmeli whose 5D space-time-velocity metric explains both galactic rotation curves and the flatness of the universe—without dark matter or other fudge factors and explains more of the data. Halton Arp also in the past suggested that observed arcs in vicinity of clusters are not the result of gravitational lensing but ejections of galaxies and matter from other clusters, i.e. the filament connecting the clusters of galaxies[7] might be associated with ejection events of one galaxy giving birth to another.[note 3] Such hypothesis undermines the standard big bang cosmology which assumes all matter originated in the initial big bang.[6]

Contents

The first dark matter

Main Article: Vulcan

The first recorded instance of the invocation of anything similar to dark matter was the hypothesis of a planet named Vulcan in the mid-1850s. This planet was supposed to be inside the orbit of Mercury and yet was never directly observed from Earth, for reasons that no astronomer ever explained. Astronomers inferred the existence of this planet because Mercury precessed in its orbit around the Sun by 43 arc-seconds per century faster than expected by Newtonian physics. Many apparently observed transits of unidentified objects across the sun were thought to be this undiscovered planet.

Then in 1915, Albert Einstein solved the problem. He showed that Mercury, at perihelion, passes close enough to the Sun for General Relativity to require a second-order correction. He published the correction and accounted exactly for the precession in the orbit of Mercury, without the need for any planet, asteroid belt, or other object or objects inside that orbit.[9] This is considered one of the first strong proofs of relativity, of many.

The current problem

Sky wmap.jpg
The current problem involving a mass deficit in astronomical observations has been known since the 1930's, when astronomers first found serious differences between the masses they inferred by examining orbital speeds and the masses they inferred by measuring stellar, galactic, and other visual magnitudes. The classic gravitational equation, derived from the theory of gravity of Sir Isaac Newton, gives the total dynamical mass in any system that is inside the orbit of any given body (for example, a particular star in its galaxy):

M = \frac{v^{2}R}{G}

where R is the distance of the body from the barycenter, v is the orbital speed of that body, and G is the gravitational constant.

The luminous mass of any galaxy or other object is the mass that corresponds to the measured light from the object.

Jan Oort first determined that the total mass of our galaxy was insufficient by a factor of at least two to account for the galaxy's rotational speed.[10] The swiss astronomer Fritz Zwicky is also credited with the discovery of the discrepancy between dynamical and luminous mass, in 1933. Zwicky examined the Coma supercluster, and found that its dynamical mass exceeded the luminous mass by a factor of ten.[11][12][13]

Image of galactic cluster with ring of alleged dark matter around it
Since that time, astronomers have assumed that some form of matter, which gives off no measurable radiation, is nevertheless present in various galaxies and galactic clusters that clearly spin faster than their measured luminous masses would predict.[14] They acknowledge, however, that the notion of a new, non-luminous form of matter is difficult to accept. Yet many astronomers insist that they have observational evidence for which dark matter remains the only plausible explanation. One such communication comes from the Chandra X-ray Center, whose astronomers stated in 2006 that they had observed two galactic clusters for hundreds of hours, and that each one clearly showed a rotational speed consistent with far more mass than was visible.[15]

Creationistic explanation

Creationism, of course, declares that any observed effect results from the creative action of God. In 2000, relying primarily on this theory, Don DeYoung, writing in the Creation Research Society Quarterly,[16] concluded that the hand of God was responsible for holding rapidly spinning galaxies and larger systems together, despite the observed mass deficits. This is not a scientific explanation, as it does not explain the phenomenon in anything but the most general terms, and makes no observable predictions.

Most creation scientists, however, prefer to assume an economy of miracles. In that spirit, John Hartnett has produced a solution that requires no continuing miracle, but derives from a new understanding of the creation and expansion of the heavens.[9] Hartnett's system builds on the earlier work of Carmeli, who in 1996 proposed an extension of Einsteinian relativity to the cosmic scale (Cosmological Relativity). The Hartnett system, explained more fully in his work Starlight, Time and the New Physics, predicts that an expanding universe will produce rapidly spinning galaxies and larger systems as a consequence of the expansion and not due to gravity (or any other force) alone.

The key concept of the Carmeli-Hartnett cosmological relativity system is the description of the cosmos, not as space-time, but as space-mass-velocity. The velocity in view here is the radial velocity of objects in an expanding universe, which is always a function of the distance from the center of the expansion, as:

v = \bigg( \frac{1}{\tau} \bigg) r

where τ is a constant (evaluated at 4.28 * 1017 s) that is the reciprocal of the Hubble factor H0 in weak gravity.[17]

More to the point, Carmeli and Hartnett showed that space itself expands in any galaxy or larger-sized object. Hartnett then showed that this expansion predicts a significantly increased rotational speed for any particle in that object.[18] Specifically,

v^4 = GM\frac{2}{3}a_0\Bigg\{\bigg(\frac{R}{2a}\bigg)^{9/2} 8 \Pi^{3/2}\Bigg\}

where R = radial position, a0 is a critical acceleration value, G is the gravitational constant, M is the total luminous mass of the galaxy (or group or cluster or supercluster) involved, and Π depends on the Bessel functions of the ratio R/2a.

The above equation is very similar to the Tully-Fisher relation between luminosity and maximum rotational speed,[19][20]

v^4 \propto L

where L = luminosity, or

A = k + 4 \times \ln v

where A = absolute magnitude. The Tully-Fisher relation was empirical, but Hartnett has given it a theoretical basis. Furthermore, the M given in Hartnett's equation is the regular luminous mass and not a Newtonian dynamical mass. Hence, no correction for any dark-matter proportion is necessary.

Hartnett tested his equation against the observed values of circular velocity of tracer gases in object NGC 3198 as a function of radial distance from the center. He found that this equation fit the observations almost exactly, while a traditional Newtonian equation for radial velocity,

v^2 = \frac{GM}{R}

predicted circular velocities much lower than observed. Hence Hartnett's conclusion that luminous masses are correct, but the physical model that predicts radial velocity is incorrect. Thus, as Einstein obviated the planet Vulcan, Hartnett now claims to obviate dark matter.

Evolutionistic concept

Estimated proportion

Cosmos percent comp.jpg
The Wilkinson Microwave Anisotropy Probe (WMAP) team at NASA has used measurements of cosmic microwave background radiation[21] to determine that the universe is geometrically flat. According to standard cosmology, the universe should then be at a critical mass density of 9.9 * 10-27kg/m³. The actual mass density of the universe is more than twenty times less than that.[22]

Current theory suggests that the familiar baryonic matter (composed of atoms) constitutes only 4.6% of the total mass-energy in the universe. Dark matter constitutes 23% of the total, while dark energy comprises the remaining 72%.[22]

Dark matter filaments on the galactic scale have been directly measured, and are considered to be a major factor in the super-galactic structure of the universe. [23]

Proposed explanations for dark matter

Evolutionistic astronomers have generally focused on the following explanations for the discrepancy between dynamical and luminous mass:

  1. Brown dwarf stars and similarly massive but relatively non-luminous objects. Astronomers have in fact invented a new name for a class of objects that include brown dwarf stars and other massive objects: Massive Compact Halo Objects, or MACHOs.[11][13][22][24]
  2. Supermassive black holes. Astronomers are now attempting to detect these objects by their relativistic effects on light, in which they act as lenses.[22]
  3. New, previously unknown forms of matter. Many cosmologists have formed hypotheses that suggest entirely new particles of matter. They call these Weakly Interacting Massive Particles, or WIMPs.[22][11][13] Other cosmologists have suggested other types of particles, named axions.[9][25] The recently sought Higgs boson is another proposed dark-matter elementary particle.
  4. A new theory of gravity. In 1983, Mordecai Milgrom first suggested that Newtonian dynamics was insufficient to explain the gravitational interactions of massive objects like galaxies and galactic clusters. He therefore suggested a Modified Newtonian Dynamic, or MOND, in which gravitational attraction varied inversely to the first power of the orbital radius, not its square as Newton originally assumed.[9][10]
  5. Neutrinos, which are detected and fall under the category of "warm dark matter" based on their momentum. However, they only account for a small fraction of the dark matter required to explain the structure of galaxies.

Criticisms of the dark-matter concept

Creationistic criticism

Don DeYoung challenged the notion of dark matter as a fanciful concept with little justification.[16] He pointed out that none of the conventional explanations popular at the time were satisfactory:

  1. Non-luminous stars, the usual candidates for MACHOs, would have to be far more common than they actually are, by several orders of magnitude, for them to account for the mass deficit.
  2. Black holes are a theoretical construct that have not thus far been verified.
  3. Efforts to detect WIMPs and axions have thus far produced no definitive findings.

This criticism has lost validity, however, as dark matter has been directly measured in filaments.

DeYoung also challenged the notion that galaxies or galactic clusters were necessarily stable. He did not comment directly on Milgrom's modified dynamic, but he did suggest that gravity was poorly understood.

Secular criticism

Tim Thompson[10] has recently suggested that the major attractive force that allows galaxies and systems of higher mass to rotate with such excessive speed is not gravity at all, but electrostatic forces. He reminds his readers that electrostatic forces are stronger than gravity, and also that the strength of a magnetic field varies inversely as the first power, not the square, of the distance from the center. This is very close to Milgrom's MOND, with the advantage of having an underlying theory to explain it,[10] which Milgrom's system does not have.[9] More to the point, Thompson suggests that the quality that allows galaxies to spin so rapidly is not mass, but electric charge. However, c and he has never been able to publish them in any reputable publication.

Controversy over detection of dark matter

Several attempts has been made by proponents of Big Bang cosmology paradigm to establish the existence of dark matter as fact and demolish the criticisms of ‘dark matter sceptics’.[26][27] The latest claim published in journal Nature (04 July 2012) is that "A ‘finger’ of the Universe’s dark-matter skeleton, which ultimately dictates where galaxies form, has been observed for the first time." Despite the bold statement that "Researchers have directly detected a slim bridge of dark matter joining two clusters of galaxies", the declaration seems self-contradictory as at the same time it has been admitted that the results were obtained by usage of computer simulations and astrophysicists are still faced with necessity to identify what the dark matter is made of. It has been proposed that this mysterious invisible substance that should dominate the space all around us in concentrations six or seven times more than normal matter could be either:

J.Hartnett commented on similar occasion that there are many assumptions and interpretations necessarily to be involved, and these kind of arguments typically all hinge on the interpretation of the gravitational lensing evidence, i.e. whether the correct physics has been applied. He points out that some claim dark matter comprises heavy neutrinos. If it was standard neutrinos, there would need to be about 10 billion times the amount of the normal matter made from protons and neutrons. Hence the need to look for a massive neutrino. But there are supposed to only be about 20 particles per cubic centimetre! It seems more than prudent to adopt a ‘wait and see’ approach on this alleged ‘proof’. J.Hartnett concludes that whether or not the dark matter in some form turns out to be real stuff, its ‘existence’ at present appears to be largely based on an underlying motive to keep a belief system that is fundamentally flawed.[6]

See Also:

Tully-Fisher relation

Notes

  1. cf. "...much of the support for the existence of the dark matter is due to the observed very high velocities of gas molecules or galaxies. For example galaxies in the far-off Coma-cluster are observed whirling around one another faster than the laws of physics would allow. So is the mysteriously rapid rotation of spiral galaxies."[1]
  2. cf."However, to get the [Big Bang] theory to work, a universe comprising 22% dark matter is an absolute must."[6]
  3. cf."There is much evidence that galaxies, quasi-stellar objects (quasars), etc. are generated and ejected from galactic nuclei (as Arp has shown), and not from initial density fluctuations in the universe shortly after the Big Bang. The observed rapid release of large amounts of energy from galactic nuclei could conceivably come from creation process that are occurring in the present-day universe."[8]
  4. cf."Researchers have directly detected a slim bridge of dark matter joining two clusters of galaxies, using a technique that could eventually help astrophysicists to understand the structure of the Universe and identify what makes up the mysterious invisible substance known as dark matter...Refining the technique could also help to pin down the identity of dark matter — whether it is a cold (slow-moving) particle or a warm (fast-moving) one, like a neutrino — because different particles will clump differently along the filament."[4]

References

  1. 1.0 1.1 Moshe Carmeli (2002). Cosmological Special Relativity, The Large-Scale Structure of Space, Time and Velocity, 2nd Edition. World Scientific Publishing, 22. ISBN 9-789-02-4936-5. “Remark on Dark Matter: As is well known much of the support for the existence of the dark matter is due to the observed very high velocities of gas molecules or galaxies.For example galaxies in the far-off Coma-cluster are observed whirling around one another faster than the laws of physics would allow. So is the mysteriously rapid rotation of spiral galaxies. Equation (2.25) clearly shows that the observed velocity by us is not the velocity measured by a local observer at a relative time t with respect to us. He measures a smaller velocity, and the more back in time the more the velocity decreases. Does this mean that the hypothetical dark matter can be abolished as the "luminiferous ether" was proved to be superfluous by special relativity?” 
  2. F. Zwicky (1933). Die Rotverschiebung von extragalaktischen Nebeln (German) 110-127. Helvetica Physica Acta.
  3. Michail S. Turner. Dark Matter, Dark Energy and Inflation: The Big Mysteries of Cosmology 0h:37min:00sec/1h:11min:39sec. Arizona connection, Lectures series. Retrieved on 2012-10-14. “So how he did discover the Dark Matter? He was the first astronomer to study the clusters of galaxies. Clusters of galaxies are joint collections of 2000 or 3000 galaxies. F.Zwicky measured how fast these galaxies are moving. ...thousands of km per second ...He asks himself if these galaxies are moving so fast, what keeps the clusters together? And the answer is: Should be gravity, the gravity is a universal glue that holds things together. The planets in our solar system move fast, not quite this fast, and it is the gravity of our Sun that holds the Solar system together. There was little problem though: If you add up all the gravity of all the stars in all the galaxies it is not enough to hold the clusters together - it is off by factor of 50. Zwicky was bold enough to say that clusters must be held together by the gravity of unseen material, "Dark Matter".”
  4. 4.0 4.1 4.2 Zeeya Merali (04 July 2012). Dark matter’s tendrils revealed: Direct measurement of a dark-matter ‘filament’ confirms its existence in a galaxy supercluster.. journal Nature. DOI:10.1038/nature.2012.10951. “The team's computer simulations suggest that roughly another 10% of the mass could be due to visible stars and galaxies. The bulk, therefore, must be dark matter, says Dietrich.”
  5. Jörg P. Dietrich et al. (12 July 2012). A filament of dark matter between two clusters of galaxies 202–204. journal Nature. DOI:10.1038/nature11224.
  6. 6.0 6.1 6.2 John Hartnett (2006). Has ‘dark matter’ really been proven? Clarifying the clamour of claims from colliding clusters. Journal of creation. Retrieved on 2012-10-14. “Halton Arp suggested that these arcs, which are very prominent in the Abell 2218 cluster, are not the result of gravitational lensing but ejections of galaxies and matter from other clusters. Of course that flies in the face of standard big bang cosmology, which assumes all matter originated in the initial big bang. See Arp, H. C., Seeing Red: Redshifts, Cosmology and Academic Science, Apeiron, Montreal, 1998; and review, Hartnett, J.G., The heavens declare a different story! J. of Creation 17(2): 94–97, 2003. Note also that the redshift of the Bullet cluster is near 0.3 which is one of the discrete values that Arp claims is associated with ejection events of one galaxy giving birth to another.”
  7. N. Werner et al. (01 April 2008). Detection of hot gas in the filament connecting the clusters of galaxies Abell 222 and Abell 223 L29 - L33. Astronomy and Physics. DOI:10.1051/0004-6361:200809599. Retrieved on 2012-10-14. “About half of the baryons in the local Universe are invisible and - according to simulations - their dominant fraction resides in filaments connecting clusters of galaxies in the form of low density gas with temperatures in the range of 105 < T < 107 K. This warm-hot intergalactic medium has never been detected indisputably using X-ray observations.”
  8. Alex Williams, John Hartnett (2005). Dismantling the Big Bang. Green Forest, AR, USA: Master Books, 346. ISBN 978-0-89051-437-5. 
  9. 9.0 9.1 9.2 9.3 9.4 Hartnett, John. Starlight, Time and the New Physics. Creation Book Publishers, 2007. ISBN 9780949906687.
  10. 10.0 10.1 10.2 10.3 Thompson, Tim. "Missing 'Dark' Matter." The Electric Cosmos, n.d. Accessed July 28, 2008.
  11. 11.0 11.1 11.2 Silk, Joe. "Dark Matter." Department of Astronomy, University of California-Berkeley, ca. 1995. Accessed July 28, 2008.
  12. Soter S and deGrasse-Tyson N, eds. "[Fritz Zwicky's Extraordinary Vision]." Excerpt from Cosmic Horizons: Astronomy at the Cutting Edge, New Press, 2000. ISBN 978-1565846029 Accessed July 28, 2008.
  13. 13.0 13.1 13.2 Miller CM. "Cosmic Hide and Seek: the Search for the Missing Mass." 1995. Accessed July 28, 2008.
  14. Authors unknown. "Dark Matter Mystery." Field Guide to X-ray Astronomy, Chandra X-ray Center, Harvard University, Cambridge, MA, August 29, 2006. Accessed July 28, 2008.
  15. Hupp E, Roy S., and Watzke M. "NASA Finds Direct Proof of Dark Matter." NASA, press release 06-297, August 21, 2006. Accessed July 28, 2008.
  16. 16.0 16.1 DeYoung DB. "Dark Matter." Creation Research Society Quarterly, 36(4), March 2000. Accessed July 28, 2008.
  17. Evolutionistic astronomers might assume that this value gives the age of the universe; it does in fact give a value very close to the visible radius of the universe, measured in light-years. It probably does represent a value that an observer at the limits of the visible universe might measure for its age—because the Carmeli-Hartnett system also predicts tremendous time dilation at the center of the expansion.
  18. Hartnett JG, "Spiral galaxy rotation curves determined from Carmelian general relativity," Int. J. Theor. Phys. 45 (2006) 2118-2136. arXiv:astro-ph/0511756 doi:10.1007/s10773-006-9178-0
  19. Tully RB and Fisher JR, "A New Method of Determining Distance to Galaxies", Astron. Astrophys. 54, 661-673 (1977)
  20. "The Tully-Fisher Relation," The Astroprof's Page, April 4, 2007
  21. Hinshaw GF, and Griswold, B. "WMAP Mission Results." NASA, April 17, 2008. Accessed July 26, 2008.
  22. 22.0 22.1 22.2 22.3 22.4 Hinshaw GF, and Griswold B. "WMAP - Content of the universe." NASA, April 17, 2008. Accessed July 28, 2008.
  23. http://www.nature.com/news/dark-matter-s-tendrils-revealed-1.10951
  24. White, Martin. "Dark Matter." Department of Astronomy, University of California at Berkeley, Berkeley, California, ca. 1995. Accessed July 28, 2008.
  25. The name Axion is a registered trademark of the Colgate-Palmolive Company (USA) and was the name of a once-popular brand of laundry detergent used to pre-soak heavily-soiled garments before washing them with a conventional detergent. The astrophysicists who coined this name suggested that axions performed some kind of cosmic cleansing.
  26. Douglas Clowe et al. (19 Aug 2006). A direct empirical proof of the existence of dark matter L109-L113. Astrophys.J.. DOI:10.1086/508162. “We present new weak lensing observations of 1E0657-558 (z=0.296), a unique cluster merger, that enable a direct detection of dark matter, independent of assumptions regarding the nature of the gravitational force law. Due to the collision of two clusters, the dissipationless stellar component and the fluid-like X-ray emitting plasma are spatially segregated. By using both wide-field ground based images and HST/ACS images of the cluster cores, we create gravitational lensing maps which show that the gravitational potential does not trace the plasma distribution, the dominant baryonic mass component, but rather approximately traces the distribution of galaxies. An 8-sigma significance spatial offset of the center of the total mass from the center of the baryonic mass peaks cannot be explained with an alteration of the gravitational force law, and thus proves that the majority of the matter in the system is unseen.”
  27. Fraser Cain (2006-8-21). Galaxy Collision Separates Out the Dark Matter.
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