More from Arp et al.

[dgruss23]

Thanks, this is a good example of why the results presented in papers without any error analysis are weaker than those with them - with the analysis you present, for these two galaxies, there is a change of ~15% (in PV72).

Is that significant?

No. In terms of the result that the ScI's in Virgo are systematically redshifted it is insignificant. The changes in distance from the values stated in the paper and the numbers I gave you are typical for the observed scatter of the TFR and the uncertainty in the data.

The point of the Virgo cluster section of the paper was to provide a better test of the arguments presented by Arp (1988) . Notice in that paper no distances were provided for individual galaxies. The galaxies were simply grouped by morphology and mean redshifts for each group were provided.

My idea was simply to test that the galaxies were actually members by calculating TFR distances. The TFR distances also allow you to determine if the mean distance of the ScI's is different than the other types.

This issue of the error analysis has been explained. Let me summarize one last time:

1. The uncertainty in the parameters was available in LEDA and therefore anybody who wished could check the uncertainty on the distances.
2. TFR papers I used as references frequently did not include uncertainty for data published in other sources, so I followed that lead. The referee did not have any objections in that regard. As an independent researcher I look at what other researchers have done and the suggestions of referee's.
3. While the uncertainty in distance and PV72 values was not published in the tables, the uncertainty in the TFR data was evaluated by myself and clearly was insufficient to explain what was found. Do not confuse the lack of a column in the data tables listing the uncertainty with a lack of investigation into the uncertainty. In fact, the major focus of the subsequent papers (including the current paper using the K-band TFR) was uncertainty in the TFR. Additional tests were provided in those papers.
4. In other sections of the paper uncertainty in the distance moduli were provided.
5. Since this is an issue you are raising, I have provided in my last post an example of the uncertainty in TFR distances for several of the galaxies as an illustration.

The point here is that if you want to show that the result can be explained as noise, then feel free to show that the result can be explained as noise. The data and data uncertainty is available to you in the literature. Unless you intend to go forward and provide such an analysis, there is nothing more to be said about the data uncertainty. I have explained above what was done and how it is consistent with what other researchers have done. Unless you have something new to say on this, I have nothing more to add. You would find that a significant amount of discussion in the subsequent papers is on this very issue.

But more important: using only the paper's inputs' stated uncertainties, what would the uncertainties in PV72 be? How would any such compare with 166 km/s?

The uncertainty in PV72 is directly connected to the uncertainty in the distance, uncertainty in the redshift, and uncertainty in the hubble constant.

Since PV72 is for a Hubble constant of 72, changing the Hubble Constant would change the PV values. How big could this effect be? Well if we went to the extreme and changed the Hubble constant to 50 km s-1 Mpc-1, then NGC 4501 (using last post's numbers) would have PV50= +1453 km s-1.

But if we stick with H0=72, and consider that redshift uncertainty is small, the uncertainty then is largely determined by the uncertainty in distance. So for a distance uncertainty of +/- 0.8 Mpc (range 0.5 Mpc to 1.1 Mpc in examples in last post depending on galaxy and band), the uncertainty in PV72 becomes +/-58 km s-1.

Now you might object, wait ... that's much smaller than the difference between the published distance to NGC 4254 and the distance to NGC 4254 with the latest LEDA update. And guess what ... you're right. That's a problem with error analysis. Published uncertainty in a data measurement is not always correct. That can go both ways. Sometimes the uncertainty for the data set is much larger than the observed scatter of the relation. Other times the uncertainty of the data does not overlap with new measurements.

Or, stating this another way, if one leaves aside all questions about selection criteria, inter-dependencies in the inputs, etc, should one read 718 and -868 km/s and go 'wow! look at that! a difference which is >25σ!' or 'ho hum, it's not even above the noise, at only 1.2σ'? Or should one say 'too bad there was no work done to estimate the uncertainties, I have no way of knowing if this is little more than noise'?

So figure it out. The data is available to you. K-S tests were performed.

Further, since such a finding, if confirmed, would be dramatic, in terms of its implications for physics, that even a simple error analysis was not done (or, if done, not written up), much less a careful, nay thorough, examination of systematics, alternative explanations, and so on, seems ... strange.

Alternative explanations were discussed in the conclusion of the paper. You also write this as if the entire basis for concluding there may be intrinsic redshifts was based upon the Virgo cluster results. That's nonsense. I never would have written the papers if that was all there was.

[dgruss23]

From the 92 'Virgo galaxies' in Thanatos' list, I select only those with LEDA inclinations between 32 and 59. Here are their NGC numbers: 4212, 4237, 4298, 4351, 4380, 4413, 4450, 4535, 4536, 4567, 4579, 4580, 4639, 4647, 4689, and 4698.

I divide the group into two, those with inclinations between 32 and 48 (Group 1), and the rest (Group 2).

In Group 1, I further require that only those galaxies with a Hubble type of 2 or higher (per LEDA) be included; for Group 2, only those with a luminosity class of 2 or greater be included.

I calculate PV72, per Russell's paper*.

Here are the values (in km/s, in ascending order):

Group 1: 61, 232, 414, 533, 870, 924, and 1013
Group 2: -1336, -1237, -970, -930, -788, -686, -252, and -612.

Average Group 1: 578 km/s; average Group 2: -782 km/s.

(application of a Kolmgorov-Smirnov test to these data is left as an exercise to the reader)

Clearly, this toy example confirms the existence of 'intrinsic redshift' among low-ish inclination galaxies of Hubble type 2 and higher, when compared with high-ish inclination galaxies of luminosity class 2 or greater.

Or does it?

No ... of course not.

First problem with your selection criteria - inclination. It is nonsense to make an inclination restriction that has absolutely nothing to do with TFR accuracy. The inclination limits discussed earlier in this thread had a purpose... improving TFR accuracy and classification of galaxies There is no basis for restricting your sample to inclinations between 32 and 59 degrees. The range of 60-80 degrees inclination should be included.

The reason your inclination criteria doesn't make any sense is that inclination is simply a matter of viewing angle and is independent of the properties of the galaxy... except where morphological classification is concerned. Luminosity class is impossible to assign for highly inclined galaxies which is why galaxies with inclinations >~80-84 degrees cannot be utilized when using the TD-TFR.

Your "toy" is an attempt to show that it is easy to select samples that suppport a certain point of view. And of course small number statistics are part of that. Unfortunately for you, it's easy to come up with meaningless examples. Meaningful examples - on the other hand - fall right out of the data without playing games with "toys".

There is a big difference between what I did and your little "toy". I applied a uniform criteria for selection of galaxies suitable for the TFR. My ScI group and Sb/ScIII group galaxies all were required to meet the same selection criteria for Vrot, inclination, surface brightness, redshift, and accepted distance range for the Virgo cluster.

Subsequent divisions of the accepted galaxies into groups were based upon the physical parameters of the galaxies: Morphology and rotational velocity. From these divisions several very clear discrepancies emerged (discrepancies already known from prior studies - the TFR simply confirmed the earlier results).

Discrepancy #1: ScI group galaxies have larger mean redshifts than non-ScI group galaxies.

Discrepancy #2: Later type galaxies (Sbc/Sc) not in the ScI group have larger mean redshifts than earlier type (Sab/Sb galaxies)

Discrepancy #3: smaller early type galaxies (defined by Vrot for the Sa/Sb spirals and linear diameters for E/SO galaxies) have larger mean redshifts than larger galaxies of the same type.

All of these divisions are based upon physical and/or dynamical properties of the galaxies (morphology and mass)... not observables completely independent of the physical state of the galaxy (inclination). That is an important distinction that makes your toy model a meaningless comparison with what was done in my sample. There is a physical basis for all breakdowns of my sub-groups ... not so for yours.

Unfortunately, I wanted to look more closely at your selected sample, but HyperLeda seems to be down right now.

As I said before, the Virgo cluster results alone are not what I rest my arguments for intrinsic redshift upon. In fact, I consider the cluster results by far the least compelling of the arguments for intrinsic redshifts in galaxies. The other arguments in my papers are far more compelling IMO.

*2) with one modification - the TFR used is type-independent: m-M = 20.145 + btc + 5.09 (log Vrot - 2.2)

And thereby you introduce a systematic error into every TFR distance you calculated. This problem of the type effect was discussed here .

For those that think I'm selectively applying methods that favor my position, the 2004 paper illustrates that is absolutely not the case.

The ScI group galaxies are more luminous at a given rotational velocity than the Sb/ScIII group galaxies. This has a very important systematic effect if you apply a single calibration for calculating TFR distances. If this type effect is ignored, the distances to ScI group galaxies will be systematically underestimated while the distances to Sb/ScIII group galaxies will be systematically overestimated. You can see this effect illustrated for several clusters in figure 3 of the 2004 paper.

All my TD-TFR does is apply a different zero point for the two morphological groups. That's it. The slope is the same. The zero point is derived from the mean of the calibrators for the two different groups (ScI group and Sb/ScIII group)

So how does this play into my results? If I ignored the type effect and calculated TFR distances from a single calibration applied to all types irrespective of morphology (as is done by most researchers), then the resulting distances would actually produce even larger redshift discrepancies!

Why? ScI group galaxies in Virgo have been shown to have excess redshift. If I ignore the type effect, then their TFR distances become smaller and the excess redshifts become even bigger! In similar fashion the Sb/ScIII group galaxies in Virgo show a deficity of redshift. If I don't apply the type correction, then the Sb/ScIII's are pushed to larger distances resulting in even larger deficits. In other words, without the correction for the type effect the Table III discrepancy would be even larger.

The same applies for the rest of my papers. I have applied the TD-TFR to the ScI group distances. The result is that the ScI's are shifted to higher observed redshifts at their TD-TFR distances than predicted from the Hubble relation. But if I used the standard procedure in which this type effect is ignored, I could have produced a set of distances with even larger redshift discrepancies!!!

So if you want to argue that I'm just trying to generate a TFR that confirms what I want you're quite incorrect. If that was what I was going to do I could have just ignored the type effect and calculated TFR distances for which ScI's would have even larger redshift discrepancies.

In fact I will tell you that one researcher was upset with my TD-TFR calibration precisely because when I use it the ScI's are put at farther distances than with the standard TFR and thus have smaller inferred intrinsic redshifts.

So all this needs to be kept in mind. Despite what some of you imply, I am very careful to make sure that the results I've found can reasonably be interpreted as evidence for intrinsic redshifts as opposed to other standard causes. Again, see the discussion in the conclusion of the paper and the results in the two follow-up papers.

I find it rather ironic - Nereid - that you're tossing out the argument for unknown systematics all the time - and yet choose to ignore a very real systematic effect when you decide to create your own "toy".

[dgruss23]

^I think there are several posts, in this thread, by dgruss23 on this ... or, pace dgruss23, do you, TomT, regard a sample of four (or five) as big enough to draw firm conclusions?

It is incorrect for you to suggest that intrinsic redshifts were proposed based upon 4 or 5 galaxies. That's completely out of context. You must consider the evidence from all sections of the paper ... and the subsequent papers build on that. As you note, intrinsic redshifts were not truly discussed until deep into the conclusion ... after other possible explanations were discussed.

[Dave Zelenka]

Since Arp's galaxies include a great variety of 'interacting galaxies', I thought that I should post a link to the Galaxy Generator thread.

With the model proposed in the thread above, interacting galaxies illustrate the process of galaxy division. One explanation for for division would be that parent material for a new galaxy is ejected from the core of the mother galaxy. The second option would be that parent material is created along a spiral arm which then develops into a new galaxy. In either case, the new galaxy would 'peel' off and slowly move away from its parent.

[dgruss23]

It does?

In Table II, there is a line:

"Sbc/ScII-III to IV 23 19.3 1268 65.7"

Short of asking you for at least the designations of the 23 galaxies here, how could any reviewer have checked this?

This is not uncommon in papers Nereid. Look at Table 3 of Sakai et al 2000 . Or Kannappan et al 2002 . The entire sample utilized is not always listed in the papers ... in fact it is frequently not when the analysis is not presenting the data for the 1st time.

That is one of the critiques I've seen of the review process - that many referee's do not check the calculation work, but focus on the conclusions and whether or not those conclusions agree with the referee's own views.

But none of this changes my point. What you were discussing is not "independent verification" of a result. What you were discussing is simply a check on the calculation work. As I said:

A true "independent verification" involves measuring the rotational velocities and magnitudes with other instruments and other wavebands. An independent verification can also involve recalibrating the TFR with expanded calibrator sets.

[dgruss23]

And is that Hubble relation interpreted as expansion of space?

Depends upon who you talk to. Arp would say "no" the Hubble relation is not from expansion of space. Others would say that there is expansion and that the intrinsic redshift is simply superposed on top of that. But whether it is expansion or not the intrinsic redshift does not replace the Hubble relationship, it simply adds another component to the observed redshift.

I'm not entirely familiar with these theories, but I thought the point in putting the intrinsic redshift in was to get quasars to fit in with a static universe theory. But I could be wrong.

No, intrinsic redshift was not proposed because some people wanted to keep the steady state theory. The intrinsic redshift was proposed because Arp and others found some evidence they interpreted as suggesting that quasars may be local. If the quasars are local then obviously their redshifts cannot be interpreted as resulting entirely from expansion of the universe. So it was proposed that most of the observed redshift of quasars is intrinsic.

But the intrinsic redshift can still be compatible with expansion of the universe.

Has Arp et al. addressed the nature of the DLAs in terms of their idea that quasars are local? There's been a lot of studies on DLAs and their accompanying metal absorptions.

No, I haven't really seen any work on that yet. Some researchers have proposed intrinsic redshift mechanisms which they believe would explain the Ly-alpha forest, but I'm not convinced that any of those mechanisms are correct.

[Ari Jokimaki]

The second option would be that parent material is created along a spiral arm which then develops into a new galaxy. In either case, the new galaxy would 'peel' off and slowly move away from its parent.

I bet you'll find this paper interesting:

Formation of Satellites by Fragmentation of Galaxies - Vorontsov-Velyaminov (1974)

[Dave Zelenka]

I bet you'll find this paper interesting:

Formation of Satellites by Fragmentation of Galaxies - Vorontsov-Velyaminov (1974)

Perfect. Thanks...

[VanderL]

To cut a longwinding string of insinuations and accusations short, I don't think the paper under discussion should be treated anything different from any other (mainstream or ATM) paper. I fully subscribe to the scientific method of testing and re-testing, so you can put those stupid "VanderL science" remarks where they belong.

OK, so please answer the following questions, about the claims you made earlier:

Ok what? I don't see how your "apology" means I must answer those questions specifically.

1) In which post(s) in this thread, before yours (#2741), were the results of (re-)analysis "done by using sources other than LEDA", "mentioned by Dgruss23"?

2) What constitute valid tests for 'similarity'?

3) How should such tests be applied in this (Virgo cluster, LEDA, etc) case?

4) Are my "findings" [of the different average PV72 values, for two other 9/8 groups selected from among the 17 Table III galaxies] significantly different from the Russell paper's conclusions?

5) How much of a change, between the PV72 values in the paper and revised ones obtained using different inputs, is considered significant?

6) What are the methods used to determine significance?

1. Don't know which one, but he specifically mentioned not using LEDA anymore.

2. Trends should be the same (the specific galaxies showing "excess redshift" should always show this excess no matter the source of data)

3. Other sources that classify all the galaxies in Virgo. Other galaxy clusters (or streams).

4. I think Dgruss23 already answered that.

5. If it changes from excess to no excess.

6. P-values?

I don't understand this question - could you clarify please?

Table III lists several galaxy types, did you throw together different type?

Cheers.

[VanderL]

You may not like them, but they are certainly valid criticisms. Dgruss explained why his sample population was so small, and clearly it is not his fault. But that does not make the sample size any bigger.

That's why he used other galaxy groups, so no the criticisms (plural) are not valid.

No, actually that is a fact. "Intrinsic redshift" is not the null hypothesis. "Intrinsic redshift" is not the automatic and necessary conclusion whenever someone finds some odd pattern in the configuration of objects in the sky. If you want to reach a conclusion of "intrinsic redshift," it will have to be based on its own merits.

And isn't intrinsic redshift based on "it's own merits"?
No intrinsic redshift is an assumption, not a fact.

I don't normally speak for the scientific community, but in the context, such an interpretation is clearly applicable and based on observation.

?????

And lastly, I take issue with your insinuation that it is somehow wrong for proponents of intrinsic redshift to report the evidence.

I'm not sure where you come up with this,

Really? You must have missed the bolded part of what you wrote here (my bold):

(in the sense of "I can't explain this, therefore it has to be what I've been looking for for the past 30 years, i.e., intrinsic redshift!").

but such a persecution complex does seem consistent with the Arpian worldview.

And here is another vintage "Cougar" tactic for anyone to see.

Cheers.

[Thanatos]

Just to keep discussion lively, some readers may recall I applied the 'intrinsic redshift based on morphology' conjecture to a fairly large number of galaxies, selected at random from the LEDA catalog, and found no statistically significant correlation.

[VanderL]

Just to keep discussion lively, some readers may recall I applied the 'intrinsic redshift based on morphology' conjecture to a fairly large number of galaxies, selected at random from the LEDA catalog, and found no statistically significant correlation.

Why don't you submit your results for publication, so the whole world can see that intrinsic redshift is not based on morphology?

Cheers.

[TomT]

Just to keep discussion lively, some readers may recall I applied the 'intrinsic redshift based on morphology' conjecture to a fairly large number of galaxies, selected at random from the LEDA catalog, and found no statistically significant correlation.

Hi Thanatos,
Would you tell us which of your posts you are referring to. What did you use for the distance calculation for the galaxies you used?
TimT

[TomT]

Just to keep discussion lively, some readers may recall I applied the 'intrinsic redshift based on morphology' conjecture to a fairly large number of galaxies, selected at random from the LEDA catalog, and found no statistically significant correlation.

Hi Thanatos,
You must have overlooked my question asking which of your posts you were referring to in the above. I did some digging and believe this must be it.

http://www.bautforum.com/showpost.ph...postcount=2557

There are many comments to be made on your analysis, but for starters I am only discussing your use of the parameter "mup" from LEDA. LEDA uses the equation mup = btc + 6.5*logVrot + 6.3 to calculate the distance modulus for any spiral galaxy. Both Russell and astro_ uk warned of the pitfalls when using a "one size fits all" for this calculation. That's why Russell went to great lengths to develop the Type Dependent - Tully Fisher Equations (TD-TFR). We have a handy method to illustrate the problem with using mup, namely the Cepheid distances presented in Table 1 of the Russell paper. I have calculated the Cepheid distances using mup in the table that follows.

Tully Fisher Calbrators
ScI Group
mup=btc+6.5*logVrot+6.3

ID LogVrot btc m-M ceph D ceph mup Mpc mup %error
N4321 2.338 9.79 30.91 15.21 31.29 18.09 18.96
N4535 2.270 10.35 30.99 15.78 31.41 19.10 21.06
N4536 2.230 10.43 30.87 14.93 31.23 17.58 17.76
N253 2.292 6.99 27.98 3.94 28.19 4.34 10.05
N1365 2.397 9.90 31.27 17.95 31.78 22.70 26.50
N1425 2.270 10.83 31.70 21.88 31.89 23.82 8.89
N2903 2.282 8.86 29.75 8.91 29.99 9.97 11.84
N3198 2.184 10.22 30.70 13.80 30.72 13.91 0.74
N3627 2.326 8.98 30.01 10.05 30.40 12.02 19.62
N4258 2.327 8.39 29.51 7.98 29.82 9.19 15.11
N4603 2.358 11.35 32.61 33.27 32.98 39.39 18.41
N7331 2.424 9.31 30.84 14.72 31.37 18.76 27.41
16.36
SbScIII group

N4548 2.279 10.66 31.05 16.22 31.77 22.63 39.54
N224 2.411 3.20 24.48 0.79 25.17 1.08 37.50
N2841 2.488 9.52 30.74 14.06 31.99 25.03 77.99
N3031 2.375 7.14 27.80 3.63 28.88 5.96 64.25
N3351 2.232 10.06 30.00 10.00 30.87 14.91 49.14
N3368 2.336 9.74 30.11 10.52 31.22 17.57 67.03
N4527 2.260 10.63 30.75 14.13 31.62 21.09 49.28
N4649 2.215 11.80 31.71 21.98 32.50 31.59 43.71
N4725 2.325 9.75 30.46 12.36 31.16 17.08 38.20
N598 2.011 5.73 24.62 0.84 25.10 1.05 24.82
N2090 2.146 10.96 30.350 11.75 31.21 17.45 48.53
N2403 2.104 8.24 27.540 3.22 28.22 4.40 36.52
N2541 1.989 11.61 30.250 11.22 30.84 14.71 31.13
N3319 2.043 11.34 30.620 13.30 30.92 15.27 14.79
N4414 2.344 10.65 31.240 17.70 32.19 27.37 54.60
45.14

The first 4 columns in the Table are: Galaxy name, logVrot, btc, Cepheid distance modulus - all input data. The next 3 columns are the calculated values of Cepheid distance, mup, and Distance from mup. The last column is the % error of the mup distance. The last line below the 12 Cepheids in the ScI group is the average error of the mup distance for these. Likewise, the last line below the SbScIII group is the average % error for those 15 galaxies.
The size of the average errors, shows why you have to derive TD-TFR equations to get accurate distances. 45% (78% max) and 16% (27% max) on average is unacceptable for any kind of decent analysis. Compare this with Russell's type dependent equation accuracy of .2% (7% max) and .4% (14% max).
This makes the rest of the analysis in your post dead at the starting gate, because the analysis tool has a fatal flaw.

TomT

[Thanatos]

Agreed. I took the LEDA data at face value and asserted the morphology dependent peculiar motion conjecture is weak. Not sure what you mean by 'the analysis tool is weak'. I don't have a theory, nor any analysis more sophisticated than plain vanilla statistical significance tests.

[TomT]

Agreed. I took the LEDA data at face value and asserted the morphology dependent peculiar motion conjecture is weak. Not sure what you mean by 'the analysis tool is weak'. I don't have a theory, nor any analysis more sophisticated than plain vanilla statistical significance tests.

By analysis tool being weak, I meant that using "mup" as an analysis tool for two different types of spiral galaxies is weak (fatal flaw), because it is not type dependent. In effect, it produces an averaged result, and this masks out the real differences. So saying you cannot detect any significant statistical correlation between morphology types using mup would be expected, because, by design, you have forced the results to be the same.
So the conclusion is, you have to use type dependent equations to do the analysis correctly.

TomT

[Thanatos]

No argument there. There are some apparently huge discrepancies between mup and mucin distances in the LEDA database - but few people appear to be shocked by that. I encourage you to consider that question before objecting to my criticisms of Russell's conclusions. Small number samples are not convincing evidence of anything. The Cephied deep distance probe study does not offer enough evidence to support any such conclusions. I'm trying to hold his feet to the fire and admit the sample size yields inconclusive results.

[dgruss23]

Small number samples are not convincing evidence of anything. The Cephied deep distance probe study does not offer enough evidence to support any such conclusions. I'm trying to hold his feet to the fire and admit the sample size yields inconclusive results.

I've already addressed this here on December 11th. There is nothing "conclusive" about the language in the paper. The basis for inferring that there may be intrinsic redshifts is based upon much more than the Virgo cluster sample. See the rest of the paper and the follow up papers.

[TomT]

No argument there. There are some apparently huge discrepancies between mup and mucin distances in the LEDA database - but few people appear to be shocked by that. I encourage you to consider that question before objecting to my criticisms of Russell's conclusions. Small number samples are not convincing evidence of anything. The Cephied deep distance probe study does not offer enough evidence to support any such conclusions. I'm trying to hold his feet to the fire and admit the sample size yields inconclusive results.

Thanatos,
Maybe you should be clearer about what it is you want to discuss. You presented a table with data for 60 galaxies, and then gave your analysis and conclusions from that analysis. So I looked into what you presented and began a point by point discussion of it. Now, it seems you don't want to talk about your analysis anymore, and want to move on to sample size, difference between mup and mucin in LEDA, and other things.
Could you state which topic you want to discuss, and then let's stick to it for awhile. Did it occur to you that the Russell paper we are discussing, and other papers he references, are addressing the very subject you mentioned, namely, what is the cause of the difference indicated by the mup and mucin parameters. It is interesting that few people are shocked by the difference between mucin and mup distances. They must not be aware of the how this difference contradicts many elements of mainstream theory. And remember, this contradiction is illustrated by many examples involving hundreds of galaxies, not just the Virgo cluster members the discussion has focused on.

TomT

[Thanatos]

I initially thought this discussion was based on mup - mucin distances until post 2628:

". . . I didn't calculate a single redshift distance for Virgo Cluster Galaxies. I didn't calculate a single redshift distance for Virgo Cluster Galaxies. The paper utilizes the Tully-Fisher Relation. The Tully-Fisher relation is a tight relationship between the absolute magnitude and the rotational velocity of a galaxy. No redshift distances are needed. . . ."

I admittedly did not understand that comment. I fail to see how any discrepancy between the TF distance and redshift distance of galaxies can be asserted without independently comparing the two. The problem I have with the 'hundreds of galaxies' beyond the Virgo cluster originates in my inability to reproduce the Virgo sample set. Given that, my skepticism of more vaguely defined samples should be understandable. I don't think Russell 'cherry picked' anything. I merely wished to point out how easily ghosts can emerge from small samples.

[TomT]

I initially thought this discussion was based on mup - mucin distances until post 2628:
I admittedly did not understand that comment. I fail to see how any discrepancy between the TF distance and redshift distance of galaxies can be asserted without independently comparing the two. The problem I have with the 'hundreds of galaxies' beyond the Virgo cluster originates in my inability to reproduce the Virgo sample set. Given that, my skepticism of more vaguely defined samples should be understandable. I don't think Russell 'cherry picked' anything. I merely wished to point out how easily ghosts can emerge from small samples.

I can see how it would be easy to experience confusion on what is being discussed, because the parameters mucin, redshift distance, and galaxy recession velocity are all dependent on one variable, redshift. So velocity v = c*z, distance D = (c/H0)*z and distance modulus mucin = 5*log(c*z/H0) +25, where c is the speed of light and H0 is the Hubble constant. So if you have the value z, you can get any of the three.
Russell doesn't calculate redshift distances in his paper because he is working with the velocities to show that the results for Peculiar velocity lead to the conclusion that something more is needed to account for the results.
So he isn't asserting or emphasizing distance discrepencies, he is asserting discrepencies in what the velocities are telling us vs the mainstream interpretation.

TomT

[Thanatos]

Tom, How do you derive a peculiar velocity without defining the difference between the 'z' and H0 components? The equations you cite are too inbred to make this distinction.

[TomT]

Tom, How do you derive a peculiar velocity without defining the difference between the 'z' and H0 components? The equations you cite are too inbred to make this distinction.

I had thought that this had been discussed so many times, that it wasn't necessary to repeat it again. You have to have an independent, accurate measure of distance to the galaxy. That is what all the discussion and effort regarding Cepheid distances and Type Dependent - Tully Fisher equations was about.
Once you have your best independent measure of distance, D , it is converted to redshift by z = (H0/c)*D. Call this zD. This is by mainstream definition, the part of the galaxy redshift due to cosmological expansion.
You have to have a value of the Hubble Constant to calculate this. The current best mainstream number for this is 72 + or - about 5. Note that LEDA uses 70 in the calculation of mucin.
Next, the value zD is subtracted from the total redshift. This remainder is thought by mainstream to be due only to the galaxy peculiar velocity. Russell takes a detailed look at this, and concludes that there is more to it than just peculiar velocity.
This is what the discussion the last 3 months has been about.

TomT

[Thanatos]

Are you asserting the Cepheid distance is redshift independent?

[VanderL]

Are you asserting the Cepheid distance is redshift independent?

Do you have reason to think it is redshift dependent?

Cheers.

[TomT]

Are you asserting the Cepheid distance is redshift independent?

Yes. I'm curious why you ask this.
TomT

[VanderL]

Finally, I should point out that I had not intended to spend so much time on this. As I indicated much earlier, my intention was to address the nature of "intrinsic redshifts", as presented in this thread, as 'empirical', and to show that these efforts and this approach contain possibly fatal inconsistencies and unacknowledged inconsistencies.

Nereid, you have not shown that the fatal inconsistencies really exist up to this point, would it be fair to conclude that Russell's paper(s) and conclusions are:
1. Scientifically sound
2. Correct in methodology
3. Not overinterpreted
4. A good basis for follow-up studies

If so, I want you to either acknowledge this, or start producing real "fatal" objections. One does not have to agree with the conclusions, even if the paper is solid. New evidence or different analyses can change any paper's conclusions (as for example the Hipparcos distances needed a correction after several years). I would be interested in proposals that would confirm/refute the proposed intrinsic redshift component.

Cheers.

[VanderL]

Are you asserting the Cepheid distance is redshift independent?

Do you have reason to think it is redshift dependent?

Cheers.

Thanatos, maybe you missed the questions?

Cheers.

[dgruss23]

Thanatos, maybe you missed the questions?

But you are supporting an ATM idea in the ATM section of BAUT VanderL, so there is no obligation for anyone to answer your questions (in a timely fashion or otherwise) - no matter how pertinent they are. That even applies should you have a valid point and demonstrate a flaw in the challengers arguments. This forum is for gleefully attacking ATM ideas. People challenging ATM ideas apparently are not obligated to defend the statements they make (although they may willingly choose to do so). To have that happen would be dialogue.

Dialogue would run against the apparent scope of the ATM section of BAUT. Perhaps you are confused(?) (as I was for a time) and believe that ATM still runs like the BABB days where people just went ahead and discussed ATM ideas - and it was considered good form for the challenger to acknowledge a good point made by an ATM proponent just as much as the reverse.

So just keep it down until you are asked the next direct pertinent question which you will be expected to answer in thesis defense mode (in a timely fashion of course).

[TomT]

But you are supporting an ATM idea in the ATM section of BAUT VanderL, so there is no obligation for anyone to answer your questions (in a timely fashion or otherwise) - no matter how pertinent they are. That even applies should you have a valid point and demonstrate a flaw in the challengers arguments. This forum is for gleefully attacking ATM ideas. People challenging ATM ideas apparently are not obligated to defend the statements they make (although they may willingly choose to do so). To have that happen would be dialogue.

Dialogue would run against the apparent scope of the ATM section of BAUT. Perhaps you are confused(?) (as I was for a time) and believe that ATM still runs like the BABB days where people just went ahead and discussed ATM ideas - and it was considered good form for the challenger to acknowledge a good point made by an ATM proponent just as much as the reverse.

So just keep it down until you are asked the next direct pertinent question which you will be expected to answer in thesis defense mode (in a timely fashion of course).

I am in agreement with the above observation, especially in recent discussions on this particular forum. Usually a flaw in these discussions is the lack of quantitative backup by the ATMers, and they are accused of "word salad" agruments. Lately, this forum has seen quality quantitative arguments and data, presented by the Arp proponents, and the rebuttals have only been of the word salad variety. Not to say that some of the efforts by Thanatos haven't been genuine attempts to do some math, or get to the bottom of the data sources. But the response to the numerical backup has been a disappointing display. Some of the most vocal critics have shown no understanding or ability of doing anything mathematical (I'm not talking about any past or present moderators on this last point).
TomT