Difference between revisions of "Cosmology Notes"
| Line 30: | Line 30: | ||
== Arp's quasars == | == Arp's quasars == | ||
| − | + | Halton Arp, famous for his 1966 [http://en.wikipedia.org/wiki/Atlas_of_Peculiar_Galaxies ''Catalog of Peculiar Galaxies'']. Anomalous redshifts of quasars, and their association with the minor axis of foreground galaxies. Too frequent to be chance associations, too large an area to be lensing (and too frequent). | |
== Fractal large scale structure == | == Fractal large scale structure == | ||
Revision as of 05:50, 16 May 2012
Gravity Theories
Modern cosmology has a disturbing number of free parameters, and is based on only a small number of observations.[1]
Modified Gravity Theory (MOG)
John Moffat (of University of Toronto) proposes the Gravitational constant G is actually a new tensor varying with spacetime such that G/c is constant (Modified Gravity Theory). No dark matter or dark energy. [2]
Expansion as illusion
There are many interesting alternative explanations of the observed Hubble relation of H₀ ≈ 70 km s⁻¹ Mpc⁻¹. The question is whether they raise more problems than they solve.
Tired light hypothesis
The hypothesis that light is red-shifted as it loses energy to the cosmos travelling across vast distances, through some unknown mechanism that does not result in photon scatter. One potential mechanism is the Wolf Effect, where diffuse plasmas can produce a redshift in transmitted light.[3]
Time dilation
Using the antisymmetric temporal part of the Ricci tensor to replace the symmetric g tensor in General Relativity, it is possible to derive H₀ = c/R as a general time dilation of approximately 70 km s⁻¹ Mpc⁻¹, where R is the Einstein radius of the Universe (approx. 13 Gly).[4] This would mean that the observed Hubble redshift relation results from time dilation across cosmological distances, rather than the relativistic motion of galaxies in an expanding spacetime.
Horizon problem and Olber's Paradox
If light is indeed red-shifted over vast distances, then an infinite static Universe would not be ruled out by Olber's Paradox since sufficiently distant radiation would drop out of detectable range, producing an effective observability horizon.
Surface brightness anomaly
Standard Big Bang cosmology predicts surface brightness (magnitude per unit area) decreases as (z+1)⁻³ yet observations show the surface brightness of galaxies up to z=6 are constant, as expected in normal non-expanding space. Explaining this as galactic evolution results in further difficulties.[5]
Plasma physics
Cosmic Background Radiation
CBR as a local radio fog resulting from plasma scattering.[6] This also predicts a long radio absorption with distance, which is indeed observed.[7]
Long tortured history of CBR predictions, unexpected results, adding more free parameters, rinse and repeat.
Galactic rotation
Computer and laboratory simulations show that at least the ISM (if not the stars themselves) could be rotating as a plasma filament pair constrained by MHD, producing the observed flat rotation profile.[8][9] These simulations also produce a time progression through the observed galactic spiral and barred spiral morphologies, and may also explain the observed independence of the motions of the stars from that of the spiral arms, if only someone would run the simulations again. However this substitutes "we need dark matter to make it work" with "where does the colossal current driving the filaments come from?" but at least we don't have to go around making stuff up.
Arp's quasars
Halton Arp, famous for his 1966 Catalog of Peculiar Galaxies. Anomalous redshifts of quasars, and their association with the minor axis of foreground galaxies. Too frequent to be chance associations, too large an area to be lensing (and too frequent).
Fractal large scale structure
Luciano Pietronero demonstrates a fractal galaxy and void distribution in large datasets.[10]
Craziness? Okay try these on for size...
Electric stellar models
Electric Universe folks (crazy warning!) believe stars are composed mostly of molten iron and are powered like an inside-out electric arc furnace. There is no requirement for "magnetic reconnection" (which is a misunderstanding of fields anyway) to explain the massive temperature inversion from the 6000°K surface to the 2,000,000°K corona, and it can explain low neutrino flux without postulating neutrino flavour mutations because the observed fusion occurs in Z-pinches in the corona, explaining the temperature inversion. No strange convection columns or lengthy radiative transfer are required. Of course, this raises other problems instead: where is the vast electric current coming from? How is the star maintaining itself as a colossal anode for billions of years without going dark? There's only so much H⁺ it can produce.
No no - it's the neutron reactions
Enter Oliver Manuel, famous for his meteorite isotope work which contributed to our current theories of solar system evolution. Extrapolating from these theories, he now believes stellar cores are collapsed supernova remnant neutron bodies, emitting H⁺ from n-n interactions:
- "Thus solar luminosity, solar neutrinos and solar-wind hydrogen coming from the surface of an iron-rich object that formed on a collapsed SN remnant are fingerprints of energetic neutrons in the solar core. These generate luminosity, neutrinos, and an outflow of 3 x 10⁴³ H⁺ per year in the solar wind"[11]
The implications of these ideas are staggering - iron stars have probably been around for a long time, and an external arc-powered star could "burn" for trillions of years.
Warning: may contain nuts
Sadly, many proponents of some of these more maverick models are also fans of Velikovsky, believe aliens influenced ancient societies, and other such cobblers, so it's very tempting to dismiss things without evaluating them properly.
References
- ↑ Disney, M. J. "Modern Cosmology: Science or Folktale?", Am. Sci. 95:5 p383, September 2007.
- ↑ Moffat, J. W. "Reinventing Gravity". 288p hardcover, 24cm. Smithsonian, 2008.
- ↑ Wolf, E. "Non-cosmological redshifts of spectral lines", Nature 326 p363-365, March 1987.
- ↑ Jastrzebski, W. J. "Gravitation Demystified" (unpublished thesis in progress). RationalWiki, 2011.
- ↑ Lerner, E. J. "Evidence for a Non-Expanding Universe: Surface Brightness Data From HUDF", AIP Conf. Proc. 822 p60-74, March 2006.
- ↑ Lerner, E. J. "Plasma Model of the Microwave Background", Laser and Particle Beams 6 p456-469, 1988.
- ↑ Lerner, E. J. "Radio Absorption by the Intergalactic Medium,", ApJ 361 p63-68, Septemper 1990.
- ↑ Bostick, W. H., "Experimental Study of Plasmoids", Electromagnetic Phenomena in Cosmical Physics, Proceedings from IAU Symposium no. 6, ed. Lehnert, B. p87. Cambridge University Press, 1958.
- ↑ Peratt, A. L.; Green, J. C., "On the evolution of interacting, magnetized, galactic plasmas". Astrophysics and Space Science 91:1 p19-33, March 1983.
- ↑ Pietronero, L.; Coleman, P. H. "The fractal structure of the universe", Physics Reports 213:6 p311-389, May 1992.
- ↑ Manuel, O. List of papers.