I agree that breaking out the bridges thread at 1119 and keeping it alive as a separate entity would be preferable to leaving it in "More from Arp et al". Regardless of what new topic we choose to address, there will still be work relating to bridged associations that deserves to be presented in context, and not be cut off with "We're on a different topic now!". Some very interesting things have popped up in this discussion (especially the redshift differential stats in M51-type systems) and I don't anticipate dropping the question at this point. Ari has contributions to make to this subject, and it is not inconceivable that someone else may want to pitch in and help us try to find out why the statistical anomalies exist, and if they track with galaxy morphology, member size, apparent separations, etc. The answers could be important.

I'm for splitting "bridges" from the main thread - it has value (real or potential?) and should not be buried under months of off-topic posts.

Thanks to antoniseb for giving me a chance to post an index in a sticky thread, to at least provide a quick way to recall where the thread has been and find relevant papers. Now if only the next post in this thread could be numbered 1119... If that happens, I will volunteer to keep the index alive and updated, so the thread can be approached (at least to some extent) as a searchable resource to any newcomer to the topic. I think that it is important to encourage discussion and exploration, and feel that it is important in a topic like this to stick to the observations, and try to avoid categorizing people. The ideas of Arp, Hoyle, Narlikar, the Burbidges, etc are interesting, and many seem to survive (and thrive) in the face of broad surveys like SDSS. That does not mean that every person who is interested in Arpian ideas should be herded into a camp where they are forced to defend every Arpian idea. Some of us are quite uncomfortable with the variable-mass idea, and perhaps are interested in learning more about redshift quantization, but are unwilling to be forced to defend it. Arp et al have teased out some very interesting trends in observations. This does not mean that we who are open to discussing their conclusions should be forced to defend them. Thanks again.

__________________
The ether of general relativity therefore differs from that of classical mechanics or the special theory of relativity respectively, in so far as it is not 'absolute', but is determined in its locally variable properties by ponderable matter.

Albert Einstein, "On the Ether", 1924