I stated my wish to give astronomers a grilling on why they reject some of Tifft's findings that have been replicated several times, in the same way that I was grilled on why I support them. Nereid suggested that I start a thread in Q&A on the matter. I am very happy to do that.
First a couple of distinctions that I think it is important to make.
A. When looking at distance periodicity or redshift periodicity it is important to distinguish between the two cases of periodicity in redshift and the various correlation functions that use all pairs of galaxies and compute distances between them based on 3 dimensions. If redshifts are quantized then the correlation functions destroy the periodicity at small scales. I can explain this further if necessary. It is my suspicion that astronomers have not understood this point and that is why Tifft and replicators have been ignored. I would like to see evidence of whether this is right or not.
B. There are differences between large and small scale periodicity. At large scales, such as the reasonably commonly reported 128/h Mpc, the periodicity is detected in both redshift taken alone and in correlation functions. This is not true of the 72 km/s periodicity which is only detected in redshift in certain preferred frames.
From the recent thread Quantized Redshift Revisited I thought that I found the following reasonable conclusions in this summary:
1. That large scale redshift periodicity and correlation function distance periodicity seems to be well established and accepted by most astronomers as real (i.e. Broadhurst etc 128/h Mpc). Please tell me if this is not so.
2. That small scale distance periodicity as measured by correlation functions is not found. I agree with this.
3. That small scale (72 km/s etc) redshift periodicity is found provided certain constraints are followed:
a. That the data is sufficiently accurate. Tifft has shown that +/-18 km/s is the maximum tolerable uncertainty as larger errors will wash out the periods. I think more accurate is desirable.
b. That the periodicity is only true in certain reference frames as found by Tifft and others. These include one near the galaxy centre frame and one near the CMBR frame. I primarily am interested in the galaxy centre frame, because if galaxy centre redshifts are co-ordinated then we certainly would expect that to be the right frame to choose.
c. That the reference frame can be relaxed when comparing pairs of galaxies or tight groups which will have a common adjustment needed from heliocentric to galactocentric velocities. If this were not true then the 72 km/s quanta would never have been discovered in the first place.
4. That the galaxies included in the sample be restricted to spiral galaxies and not dwarf or irregular galaxies. Different quant may apply to these but the results are not replicated as far as I know.
I will mention here the original and two replications that I know of.
APJ 268:56-59 1983 May 1, Redshift Quantization in compact groups of galaxies, W J Cocke and W G Tifft (actually there is a better Tifft paper than this one which I am having difficulty finding).
APJ 345:72-83 1989 Oct 1, Periodicities in Galaxy Redshifts, Martin R Croasdale
J.Astrophys.Astr. 1997 18:455-463, Quantized Redshifts: A Status Report, W M Napier & B N G Guthrie
These papers find the results replicated in various ways at levels of p<.001 and p<.0001 on totally new samples and so are seriously difficult to dismiss as chance.
Additional replications of part of the results.
APJ 385:32-48 1992 Jan 20, Velocity Differences in Binary Galaxies I...., Stephen E Schneider and Edwin E Salpeter
From the Napier and Guthrie paper: