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Sunday, March 24, 2013 Reading - Seeing Red: Redshifts, Cosmology & Academic Science. Part 1. Reading - "Seeing Red: Redshifts, Cosmology & Academic Science" I came across Halton Arp's book some months ago while perusing my local technical library. Since Arp's work is referenced by virtually every crank claim (often in way contradictory to what the crank claim is trying to support!), I thought maybe it was time I finally read this book. I had read a number of Arp's papers over the years and been repeatedly frustrated by the number of questions left unanswered by Arp and others claiming that quasar redshifts were not due to cosmological expansion. The nature of the redshifts of extragalactic objects has been a source of controversy since their discovery in the early part of the 20th century. Our understanding of the distant cosmos depends very strongly on an accurate understanding of the distance scale from which many other cosmic parameters depend. The amount of energy we detect at the Earth emitted by an object is dependent on its intrinsic luminosity and the distance. This is critical to understanding other aspects of the phenomenon. While the Hubble Law (Wikipedia) has reigned as the dominant explanation that fit the great majority of the data, occasional discovery of a new class of objects would almost always present some challenges. Numerous alternative explanations for the redshift have been explored. When quasars (Wikipedia) were discovered in the 1960s, the distances inferred from their red-shifts and the Hubble law suggested that they must be incredible sources of energy. The difficulting explaining such energy output generated some concern that perhaps for this class of objects, the redshift was not a reliable indicator of distances. When Arp and others first brought attention to quasars very close to regular galaxies on the sky, there was a flurry of interest. Arp (wikipedia), Geoffrey Burbidge (wikipedia), Jayant Narlikar (wikipedia), Fred Hoyle (wikipedia) and others developed a cosmological model derived from Hoyle's earlier steady-state cosmology. Arp pursued the idea that quasars were actually ejected objects from the nearby galaxy and that much of the redshift observed was intrinsic to the quasar and not due to distance. For a time, Arp's observations suggesting that the red-shift might not apply the quasars received a lot of attention. Eventually, it was realized that these 'alignments' were not actual associations, but due to chance placements on the sky. The great majority of the astronomical community found the cosmological redshift had far more successful predictions than Arp's model. Beyond the scientific issues, of my greatest complaints about this book is it's somewhat chaotic organization. It is not organized historically or by objects, or even thematically. Each chapter seems to drift into discussions that might be better served collected together. It reads almost like a set of essays originally written as separate pieces which were subsequently published together. I'll attempt to consolidate some of the themes, which better illustrates some of the errors. Arp often discusses how ideas changed - what we used to believe, vs what is believed now. However, he fails to mention that these new ideas often had associated problems which had to be solved before the idea became accepted. Arp's ideas failed to solve many of their problems. The Chapters: Chapter 1: X-ray observations confirm intrinsic redshifts Chapter 2: Seyfert Galaxies as Quasar Factories Chapter 3: Excess Redshifts all the Way Down Chapter 4: Intrinsic redshifts in stars Chapter 5: The Local Supercluster Chapter 6: Clusters of Galaxies Chapter 7: Gravitational Lenses Chapter 8: Quantization of redshifts Chapter 9: Cosmology Chapter 10: Academia The Odds Must be Crazy (with apologies to the Website & Podcast) One of the greatest potential pitfalls of Arp's hypothesis was that these alignments could be perfectly ordinary chance alignments between bright foreground galaxies and more distant, but brighter, background objects. Arp and supporters were always very quick to quote some small probablity (usually < 1 in 100) that the alignments were chance. When I first started reading these papers, I was often frustrated that many of these authors did not publish just what assumptions went into the probability calculation or did not provide clear direct references to the papers that did. I eventually found the methodologies, but it took quite a bit of digging. Humans have a lousy sense of probabilities. If they understood probabilities well, Las Vegas would be a ghost town and lotteries would fold for lack-of-interest. Yet a huge part of Arp's evidence is based on his computations of these probabilities, claiming that the odds of any two or more of these objects being so close by chance is very low. Perhaps the simplest problem to illustrate part of Arp's probability errors is the Birthday Problem (Wikipedia). In this problem, the probability that YOU share a birthday with anyone in a roomful of some number, N, other people is significantly lower than the probability that any two people in that same room will share a birthday. Yet most people think these two probabilities should be equal. If you were searching a room of 23 people for matching birthdays, you'd express suprise if you found two people that matched, yet the real probability is about 50% that you would find two matching birthdays in the room. Arp continued to draw attentions to correlations he finds while ignoring the far larger quantities of uncorrelated galaxies, which made his probabilities seem more significant than they actually were. If a probability of an alignment is 1%, then in a catalog of 100 randomly distributed objects, you would expect one or even two alignments. If you went looking for alignments, any one you found would be significant. As galaxy catalogs grew significantly larger than a few hundred, it was becoming clear that chance alignments were a significant probability. Arp attempts to dismiss these by arguing that you can turn any alignment into a chance correlation if you go to sufficiently deep magnitudes, a tactic which Arp calls the 'Pleiadies maneuver' (pg 103). There was also this apparent correlation that the closer the quasar was to the galaxy, the larger it's redshift. Arp argued that if galaxies were truly spread randomly on the sky, there should be no correlation between these two quantities. That these two quantities should have this interesting correlation was strong evidence to Arp that the quasar-galaxy association was real. But Arp never really properly tested this against the cosmological redshift interpretation. This is only strictly true for a 2-dimensional sky - as if Earth were inside a sphere an all the universe were on the surface of that sphere. It would fall to Noerdlinger (ADS) to give a surprisingly simple, GEOMETRIC, explanation of this correlation for a 3-dimensional universe where redshift was proportional to the radial distance. Below I've generated a view of a few degrees of sky from one of my simple cosmology models illustrating what you would see. Click to Enlarge Click the plot to look at a larger version. In this simulation, each dot represents a galaxy sampled from a volumeof randomly distributed points. The colors are assigned based on distance from the observer, with blue being nearest, and red being furthest. Size of the dot is also based on distance, with the closer dots being larger. One characteristic we immediately notice is that the bluer dots tend to be larger but fewer, while the orange and red dots are consistently smaller and far more numerous. It turns out that the mean angular distance we see between the galaxies gets smaller the further away they are. This is the origin of the angular distance-redshift relationship - a simple example of visual perspective (wikipedia). My simulation above was generated with a uniform poisson distribution in space of the same mean density, no there is no clumping of galaxies due to gravity. Yet how many close associations can you find, in this one sample plot, of a (large, blue) foreground galaxy with a more distant (small, red) background galaxies? What about objects in a line of three or more? The Noerdlinger paper was an interesting discovery which I will explore more in a future post. But while Arp tried to make a point that is was the nearness of quasars to galaxies, measures of a few arcminutes and less, that was the important characteristic (Table 1-1, 1-2, figure 1-5, 1-9, 1-11, 1-20, 2-3, 24, ), he also claimed associations for quasars and galaxies a degree or more apart. Many of fields of view in Arp's book are 1-3 degrees wide to show the association (Figures 1-6, 1-17, 2-5, 2-6, 2-10, 2-20). What's up with that? Arp's statistical computations were subjected to continual scrutiny (1977ApJ…211..311R, 1978ApJ…223..747S,1978A&A….70..219N, 1980ApJ…237..326W), but even when legitimate biases were pointed out which dramatically increased the probabilities of chance alignments significanlty larger than Arp's estimates, Arp continued to ignore these corrections. There are very few papers where these issues are actually addressed. As more of these errors were pointed out to him, it seemed that Arp began adjusting his probability calculations with a smaller a priori probabilities which were used to drive his alignment probabilities to even lower (1981ApJ…250…31A), and more dubious values (1982ApJ…263L…7B). Numerous additional researchers questioned Arp's probability computations for associations (1983ApL….23..155P,1983MNRAS.204..675Z) and claimed quasar alignments (1982MNRAS.200P..47W, 1982MNRAS.201..179W). And Arp and a few of his supporters continued to ignore these results. But as the galaxy and quasar surveys grew larger with more complete coverage of the sky, more problems were found with Arp's interpretation. We were also finding regular galaxies near quasars of the same redshift (1972ApJ...171L..83R, 1972ApJ...176L..47O). It was becoming clear to the rest of the astronomical community that the alignments were due to chance. Distances vs. Brightness One of the more annoying claims in the book was Arp stating that the redshift-distance relationship implies a strict redshift-apparent magnitude relationship (pg 153-154). This is only strictly true when the objects in question are reasonably 'standard candles' (Hyperphysics). As a population, galaxies can range in brightness over several magnitudes which can create significant spread in the result. Below is a plot from one of my model universes with just a few galaxies. The model has a gaussian distribution of galaxies in absolute magnitude with a half-width of 1.2 magnitudes. What kind of correlation can you see? I've plotted more galaxies in this sample than Arp does in his book. With small numbers of data points, sampled over a short range, it is easy to make the correlation undetectable. In Figure 6-14, Arp plots a handful of galaxies over a very narrow range of redshift, making the plot look almost random. Arp says that such a broad range of brightness for galaxies (4 magnitudes, or a factor of 40) is unrealistic. However, an even broader magnitude range exists for stars, a factor of about 10^10 =10^(0.4*25) or 25 magnitudes! What makes galaxies exempt from a broad range of brightness? Is Arp just dismissing this possibility because of the problem it creates for his particular interpretation of the data? 2-Dimensional Thinking "He is intelligent, but not experienced. His pattern indicates two-dimensional thinking" -- Capt. Spock, ST: TWOK I had this suspicion some years ago when I was reading Arp's papers individually, but seeing Arp's arguments in his book, while exploring the papers, reinforced my suspicions. I can find none of Arp's probablility calculations that treat the sky as a 3-dimensional volume with the viewer's proper perspective. Most of Arp's arguments treat the universe as if it were a 2-dimensional spherical surface centered on the Earth. His probability calculations are strictly for random points scattered on a 2-dimensional sphere. This error is intimately related to the error pointed out by Noerdlinger in paper mentioned above and which I will cover more in a future post. When Arp tries to argue for redshift 'quantization', he treats the sky as 1-dimensional, but this time in redshift space. This is a problem with many advocates of redshift-quantization. These researchers who simply run a histogram of number of galaxies as a function of redshift (actually a 3-d dataset) through a simple 1-dimensional Fast Fourier Transform. This is not a true 3-D power spectrum. If the quantization were real, why do the power spectra of individual separate catalogs peak at different frequencies? (see Quantized Redshifts. VII. Common Power Spectral Density "Bloopers") If you keep these three dimensions separate, all kinds of strangeness can be found. Yet, a consistent picture emerges when redshift is proxy for third dimension and you treat space as a full 3-D structure. I've been assembling this writeup for a number of months now and it just seems to keep getting longer. I'll have more about Arp's book, and his cosmological & quasar model, in part II. Sunday, March 31, 2013 Reading - Seeing Red: Redshifts, Cosmology & Academic Science. Part 2.. Reading - Seeing Red: Redshifts, Cosmology & Academic Science. by Halton Arp Continuation from part 1. In Part 1 of this series, I covered the claimed 'low probability' of low redshift galaxies near high redshift quasars, illustrating how considering the full 3-dimensional nature of space illustrates how the probabilities of chance alignments aren't so low. In this part, I'll cover the apparent 'connections' reported in some of these cases. Things Don't Look Good… Another problem with Arp's analysis is a heavy reliance on what something 'looks like', basically relying onpareidolia (Wikipedia). This is a common characteristic of a lot of faulty (Wikipedia: N rays) and crank science (Pseudo-Astronomy: the ziggurat on the moon). The greatest problem with this approach is one of reproducibilty (wikipedia). Without reproducibility, other people can insist that they see something completely different - and if looks are all you have to go on, how can you prove anything? Consider the claimed 'bridge' between 3C273 and 3C279 in Figure 5-17 of CompTEL data (pg 132) and EGRET data in Figure 5-18 (pg 134). Arp implies some kind cover-up in the later publication of the COMPTEL data where his claimed 'bridge' between the two objects has vanished. Both both CompTEL and EGRET obtained photon direction information in very indirect ways, by counting individual gamma-ray photons and trying to determine their initial directions based on the trajectories of electrons either scattered or pair-produced in the instrument. The angular resolution of both of these instruments was poor but improved over time through the accumulation of more photons - real sources would accumulate significantly more counts than empty backgrounds. This reinforced the statistics at locations of real sources and decreased significance of background noise. Artifacts between point sources would disappear. Similar 'connections' probably vanished all through the skymaps of these instruments over time. On page 173-174 we find the statement that the connection between lobes of the Einstein cross "Looks real" (STSci). Again, we see 'blobby' things with faint 'connections' between them, especially when blown up into a severely pixelated image. While Arp complains these 'blobs' are not shaped like the arcs predicted by gravitational lensing, it is important to note that the Hubble observations were released in 1990. HST still suffered from the optical flaw discovered after 'first light'. HST was not operating at its optimal resolution and extended objects looked far fuzzier than the ideal (Wikipedia). The first Hubble Servicing mission to fix that problem would not take place for several more years (STSci). Hubble has since taken an image where the 'connections' are less apparent. Other observations from ground-based instruments (Astronomy Picture of the Day (APOD): The Einstein Cross Gravitational Lens, Microlensing of the Einstein Cross) can have resolution limits due to atmospheric effects. Pages 178-180, we see the claim that the gravitational lensing arc does not look like a lensing artifact but rather an ejected shell. I suspect there might be spectroscopic methods for distinguishing a galaxy or QSO from an ejected shell such as the Vela supernova remnant (APOD: Vela Supernova Remnant). Actually, since gravitational lensing is often verified by a spectroscopic signature (gravity bends all wavelengths equally, so there is no dispersion), I suspect it has already been verified that this is a lensing artifact. Arp uses these observations to argue that quasars are ejected from the centers of galaxies. The ejected quasars eventually sprout spiral arms and grow into regular galaxies. He seems to suggest that most (or all?) of the galaxies we see were generated by such a process (even claiming that our own Milky Way galaxy was ejected from the Andromeda galaxy, pg 69). This is not a problem in and of itself, because we've detected things being ejected from galactic centers, particularly jets of plasma. Here's a few images compositing the visible light optical images, which show the galaxy, with the radio emission data, which reveal the jets from the galactic center, such as thesample below of Hercules A from Astronomy Picture of the Day. Hercules A with Radio Jets: NASA, ESA, S. Baum & C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA) Here's some more examples from Astronomy Picture of the Day: Jets from Unusual Galaxy Centaurus A, Messier 106. But note that in these composite images, it is easy to see that the central jets from these galaxies show turbulent structure, most likely due to interactions with the intergalactic medium. The jets form blobs, irregularities, and at large distances from the center - they slow down to form blobs that emit strongly in radio wavelengths. You can see a similar behavior using an eyedropper to force colored dye into a class of clear water. This behavior is also observed in jet simulations. UMich: Relativistic Flows MPE: Simulation of Jet-Disk Interaction Yet if there is an interaction with the surrounding intergalactic medium, it is barely visible with Arp's ejected quasars! Consider the tenuous 'connection' between Markarian 205 & NGC 4319, long regarded as the strongest case for quasar-galaxy associations (pg 22, 154-156). Markarian 205 still gets a lot of press among Arp supporters, even though it is now known that the spectrum of the foreground galaxy and redshift has been seen in Markarian 205, indicating that Markarian 205 is behind the galaxy (see The nearultraviolet spectrum of Markarian 205, APOD: The Galaxy and the Quasar, sample below). R. Knacke (Penn State Erie) et al., Hubble Heritage Team, NASA Many other claimed 'connections' between the parent galaxy and 'ejected' quasars are barely distinguishable from random blobs in the galaxy such as the 'interaction' between NGC 450 & UGC 807 (pg 83, Testing for interaction between the galaxies NGC 450 and UGC 807). Another question is if galaxies form by this ejection process and grow these spiral arms outward as they move through the intergalactic medium, why aren't these spiral arms dragging behind the galactic center, pulled back by the drag from their relative motion in the intergalactic medium? The intergalactic medium is certainly dense enough to alter the plasma jets in the images above. How can this process create such beautiful, FLAT, disk galaxies that we see such as these samples on Astronomy Picture of the Day (NGC 4945, NGC 891, NGC 2683, NGC 3628, NGC 4452)? I wonder how successful Arp and his supporters would be in identifying these disruptions in galaxy images in a double blind test (Wikipedia), where a nearby quasar has not been identified. If these disruptions were actually unique to 'ejecting' quasars, one would think you could use them to look for the quasar from the galaxy image. This is an example where double-blind testing of these would probably reveal observer bias. The Universe According to Arp Arp presents a summary of the cosmological model derived by Jayant Narlikar, Fred Hoyle and others. One of the greatest problems I have with this description is the apparent 'Rube Goldberg machine' (wikipedia) nature of the cosmos in this model. To make this cosmology work, Arp invokes all kinds of additional phenomena, only some of which have any chance of being testable. With this model, Arp claims for his data, the universe must be large and old (pg 250) compared to the Big Bang's 13.7 billion years. Yet consider this in the context of the 3-dimension problem discussed in part 1. If the universe is large and full of galaxies, you EXPECT to see plenty of background objects, which means alignments with foreground objects are very probable. For the these types of alignments to be rare, the universe must be small and finite or have a very pathological distribution of galaxies to prevent foreground-background alignments. This may be one of the unspoken reasons why Arp's claims have been adopted by so many Young-Earth Creationists and Biblical Geocentrists - it reduces the light-travel time problem for their cosmologies. Arp supports the notion that cosmological redshifts are quantized (pg 63), but in some strange ways which I have yet to find consistently explained. He does devote an entire chapter to the many different ways this is supposed to work (pg 195-224). Arp invokes a 'machion' particle to explain this quantization (pg 200-201). In the Narlikar model, mass becomes a particle property that varies with the age of the particle, specifically m = a* t^2 (pg 108-109), where t is the time since the matter was created. Narlikar claims that the change of the mass scale with time is such that objects 'look' like they are redshifted. The first problem that comes to mind is that we should measure such a process in particle accelerators, where we can actually destroy and create new particles, but we do not. Arp makes a strange dismissal of this issue on page 234 where he devotes two paragraphs to wiggle out of this problem. The second problem that comes to mind is how such a mass change would affect atomic energy levels as well as atomic sizes, which impacts chemistry and loads of other processes. These distant galaxies shouldn't just be redshifted, they should exhibit signficantly different chemistry. I covered a great many of these types of issues in my rebuttal to Barry Setterfield's c-decay claims (see "A Changing Speed of Light?"). Arp tries to describe the QSO ejection mechanism as a 'superfluid' coming out of galactic centers (pg 247248). This superfluid has some rather strange properties. It is ejected from the galactic nucleus at the speed of light, but slows and gains mass by conservation of momentum, becoming a self-gravitating object. One problem with this scenario, acknowledged by Arp, is that hot material can't collapse under gravity. When reading this, I couldn't help but think of the Red Matter of the 2009 Star Trek movie (Memory Alpha, See also Wikipedia: List of fictional elements, materials, isotopes and atomic particles, and Cosmic Variance: A Mystery Box Full of Red Matter). Arp includes a plethora of additional odds-n-ends statements 'supporting' this model... 1. 2. 3. 4. 5. 6. 7. As part of the quantization, he reports on galaxies that are spaced at intervals of 128 Megaparsecs (pg 203). Yet he fails to explain how this is consistent with the claimed quantization at velocities of 72 km/s or 37.5 km/s. If the Hubble constant is about 70 km/s/Mpc, then the gaps should appear about a Megaparsec apart. How are these two claims consistent? Arp suggests the electron spin defines an elemental time unit, but I don't find any actual time unit defined (pg 217-218). Arp includes quantization of planetary orbits with factor of 1.228^n and manages to tie this to his cosmological quantization (pg 220-221). This is apparently the claimed orbit quantization which I tried to address in an earlier post (see Geocentrism's "Quantized Planetary Orbits") before I was informed of the origin and details of the claim. There is no clear explanation of why this applies to the planets. However, one question would be what about all the other objects like asteroids and comets that occupy orbits of intermediate size that clearly violate this 'quantization'? On page 229, Arp seems to have a distorted understanding of accretion, suggesting that the jets we observed from galactic centers (such as in the earlier images of galactic jets, see Wikipedia: Active Galactic Nucleus) are a property of black holes. He apparently does not understand that these jets are not an aspect of a black hole, but rather an aspect of accretion disks (wikipedia). We observe similar jets from proto-stars (wikipedia) where the accretion disk generates a magnetic field that can collimate the plasma outflows into the jet. Arp mentions the claimed 50K temperature prediction in 1961 by George Gamow (pg 237) which was in a POPULARIZATION on cosmology, NOT a peer-reviewed publication. I'm preparing a post on this, as I've found what appears to be the source of the original claim. Arp claims that cosmological physics that assumes masses are constant in time are not valid (pg 249), calling it a 'dubious assumption'. First, we have no laboratory evidence that particle masses changing like this could be true. Arp also does not consider how such things as the fine-structure constant must change if particle masses are changing and the impact this would have on spectra beyond any redshift. Arp claims that the Cosmic Microwave Background (CMB) must come from a thin shell at the edge of space (pg 236-237). A schematic model of Arp's cosmology on pg 251 tries to tie this all together. Yet if this is the case, it doesn't explain why this radiation has such a uniform temperature all across the sky. It brings us back to the Horizon Problem (wikipedia), which was a problem for Big Bang cosmology before the discovery of inflation. This cosmology has a hodge-podge of problems which I have been unable to find addressed by its supporters beyond very weak hand-waving arguments. There are not even any viable experiments to back it up! Dark energy at least has some laboratory evidence via vacuum energy (wikipedia). Thought I could fit this review in two parts (actually, I originally thought I could finish it in one part!) but there's a little more to go. Stay tuned for Part 3. Sunday, April 7, 2013 Reading - Seeing Red: Redshifts, Cosmology & Academic Science. Part 3. Reading - Seeing Red: Redshifts, Cosmology & Academic Science. by Halton Arp Continuation from part 2. The End is Near! But the Cracks Started to Show Early I've already noted how Noerdlinger demonstrated in 1975 that Arp's 1/z separation correlation was the result of a simple geometric sampling artifact in the cosmological redshift interpretation (see Part 1 of this series). Another detail that Arp does not mention in his book is just how soon counter-examples began to arise that presented problems for quasar ejection interpretation. Most problematic were galaxies being found near quasars with a similar redshift, back in the 1970s: The Spectra of Two Galaxies Near PKS 2251+11 Redshift of a galaxy near 4C11.50 C 323.1: a QSO in a Rich Cluster of Galaxies If Arp's interpretation was correct, how could a galaxy have the SAME redshift as a nearby quasar? Perhaps they're chance alignments? According to Arp, that is not likely! In addition, other astronomers were beginning to detect structure around quasars consistent with a host galaxy(The Structure and Spectrum of Nebulosity Associated with the QSO 4c 37.43). The observations that some quasars could have the same redshifts as normal galaxies was rather quickly acknowledged by Burbidge (see Redshifts and Distances, 1979), but apparently not by Arp. But Burbidge did not recognize how damaging that fact was to the underlying model of quasars as ejected objects. The flip side was that for the cosmological interpretation of redshifts, the quasar energy production mechanism became a challenge again. By the 1990s, the Hubble Space Telescope was demonstrating that QSOs appeared to be in galaxies: J. N. Bahcall, S. Kirhakos, and D. P. Schneider. HST images of nearby luminous quasars. Astrophysical Journal Letters, 435:L11–L14, November 1994. doi: 10.1086/187582. J. N. Bahcall, S. Kirhakos, and D. P. Schneider. Hubble Space Telescope Images of Nearby Luminous Quasars. II. Results for Eight Quasars and Tests of the Detection Sensitivity. Astrophysical Journal, 450: 486, September 1995. doi: 10.1086/176159. J. N. Bahcall, S. Kirhakos, D. H. Saxe, and D. P. Schneider. Hubble Space Telescope Images of a Sample of 20 Nearby Luminous Quasars. Astrophysical Journal, 479:642, April 1997. doi: 10.1086/303926. P. J. Boyce, M. J. Disney, J. C. Blades, A. Boksenberg, P. Crane, J. M. Deharveng, F. D. Macchetto, C. D. Mackay, and W. B. Sparks. HST Planetary Camera images of quasar host galaxies. Monthly Notices of the Royal Astronomical Society, 298:121–130, July 1998. doi: 10.1046/j.13658711.1998.01617.x. P. J. Boyce, M. J. Disney, and D. G. Bleaken. Quasar host galaxy images from the Hubble Space Telescope Archive. Monthly Notices of the Royal Astronomical Society, 302:L39–L44, January 1999. doi: 10.1046/j.1365-8711.1999.02281.x. In Arp's book, he reports on a press conference where John Bahcall was announcing some of these early results (pg 55). Rather than acknowledge this was a severe blow for his model, Arp emphasized that this could not be demonstrated for ALL quasars observed. Arp's denial was in the same class as creationists complaining about gaps in the fossil record, who, when an intermediate is found, insists that evolution now has TWO gaps! Caveat Emptor As noted before, while reading this book, I took the time to read the references mentioned by Arp, as well as a number of papers which dealt with discordant redshifts NOT mentioned by Arp. As a result, I came away feeling that Arp was selling this cosmological model like he's selling used cars. It's what he's NOT telling you that's important. When confronted with contrary evidence, Arp dismisses it in a fashion that suggests his own personal incredulity. He can't believe that the contrary evidence could be this way, so it can't. The cosmological model promoted by Arp and his supporters seems designed to evade any kind of laboratory testing. The matter creation process advocated in the Narlikar model is claimed to be undetectable under laboratory conditions. Meanwhile, many dark matter searches are taking place in Earth laboratories (see Dark Matter). Which has a better chance of being demonstrated correct? The more I read Arp's cosmology description, the more I felt I was reading something akin to a Medieval cosmology (Wikipedia), where the sky (in this case the Cosmic Microwave Background) was a distant shell and the planets (or galaxies) where mounted on 'quantized' crystal spheres around the Earth! Please Don't Feed the Cranks The final chapter of Arp's book concentrated on Arp's views of academic science and other odds-n-ends. Dr. Arp complains that the Big Bang is treated as 'unquestioned dogma'. This is the same expression used by Biblical Geocentrists, Creationists, Electric Universe and Plasma Cosmology supporters, and others, about many of the same aspects of modern astronomy and cosmology. Of course, each of these groups advocate their own cosmology different from the others, so who is arguing dogma? Arp claims that the Big Bang model has so many parameters that anything can be made to work (pg 257). While Big Bang Cosmology does have a number of parameters, today there is a lot more data in the form of galaxy and cosmic microwave power spectra and polarization info that constrains the values of those parameters. Max Tegmark has generated a set of movies on his web site that illustrate how the model matches with the data for different values of the cosmological parameters. This is a very cool demonstration. While Arp complains about creationism (pg 270), a large fraction of 'creation scientists' invoke his work as evidence that Big Bang cosmology is wrong. When reading this book, I realized that large sections of Barry Setterfield's 'science' of a decaying speed of light seems to be based on Arp (see A Changing Speed of Light?). Arp even collaborated for publication with one Young-Earth Creationist, John Hartnett (see Analysis of the 2dF Deep Field). It is difficult to find a crank cosmology claim that DOESN'T invoke Arp's observations at some point. Many of these alternative cosmologies fly completely contrary to Arp's work if the Arp's interpretations are correct. I've heard that Anthony Peratt remarked that if Arp's model for quasars were correct, his Birkeland current galaxy model (seeScott Rebuttal. II. The Peratt Galaxy Model vs. the Cosmic Microwave Background) could not be correct (it is clear that Arp and Peratt's galaxy models have structures that are mutually exclusive). I have yet to find where or if Peratt actually said this and would appreciate details if anyone can clarify the issue. The contradictory nature of these two radically different galaxy models seems lost on Electric Universe supporters who routinely invoke Arp's observations. Arp has become one of the darlings of the pseudo-astronomy community because he is one of the few promoters of these types of claims that has done a lot of legitimate astronomical research. Most of his papers today seem to make it through peer review not because of Arp's discordant redshifts interpretation, but because the paper includes observations of particular objects which have not been published before but which are of value to other researchers. Claims of Abuse Arp tries to get sympathy - often mentioning how he has been 'mistreated' by the astronomical community (pg 21, 74-75). Yet he never acknowledges his errors nor their impact on his interpretation of observations while he continues to try to access multi-million dollar facilities to continue his quest. Science has established a set of general rules, called the Scientific Method (Wikipedia). While few successful individual researchers strictly follow this methodology in a systematic fashion, the group selfpolicing activity of peer-review and reproducibility in science does a good job of making sure the rules are followed and bad science eventually gets rejected. While abuses do take place (wikipedia: Scientific Misconduct), it is often on a signifcantly smaller scale than in other professions. But the fact that these rules exist, however informal, means there are penalties for those who don't want to follow the rules, or insist that they are subject to a different set of rules. Many of the pseudo-sciences dealt with in this blog insist that science must adopt a different set of rules so that their claims can become accepted science. What would you do if a mathematician insisted that (in base 10) 1 + 1 = 3? Suppose they continued to insist on this even after you gave them marbles for a counting demonstration? Suppose that instead of demonstrating with the marbles, they accused you of discriminating against them? Additional Resource: AstronomyCast: How to Be Taken Seriously By Scientists Cosmology After Discordant Redshifts... With the discord amongst the redshifts largely resolved - astronomy has moved on… Unified AGN model: Remember the images of jets ejected from the centers of galaxies? What would a galaxy look like if you were looking down the jet? This idea became the cornerstone of what is called the Unified AGN model - that the difference between quasars and other galaxies may be purely an matter of point-of view, and we see quasars when looking down the jet of an active galactic nucleus (see Wikipedia: Active Galactic Nuclei). Quasar gravitational lensing is being used to provide additional constraints on cosmic geometry (see QUASAR LENSING: THE OBSERVER'S POINT OF VIEW. by F. Courbin) Quasars in the background are being used to probe the interstellar medium of foreground galaxies (see Probing Halos of Galaxies at Very Large Radii Using Background QSOs, Lyman alpha systems and cosmology). A handful of researchers still pursue aspects of Arp's model, but it appears their numbers are declining as improving astronomical technologies turn ambiguities in astronomical observations into observational facts. Additional Resources Crank Astronomy: Halton Arp's Discordant Redshifts Crank Astronomy: William Tifft's Quantized Redshifts Wikipedia: Halton Arp W.T."Tom" Bridgman