I think Glenn exaggerates a bit but makes a point. An illustration of my
own: When the claims of cold fusion were first released my initial reaction was,
"That's impossible - of course you have to get temperatures of at least millions of
degrees to get sufficient barrier penetration to make that work." My next reaction
was to start thinking of theoretical scenarios which _could_ make it work. Other
physicists did the same thing & some of these speculations got published. Having
such scenarios didn't mean acceptance of the experimental claims but it provided
ways of making sense of them if they turned out to be correct. As it turned out,
they weren't.
Glenn is right: Science isn't just collecting observations. We immediately
want to understand those observations in the context of our view of the physical world.
Sometimes that means finding some explanation with existing theories & sometimes it
requires the development of new theories - a distinction which can be put in Kuhnian
terms.
The reason I say that Glenn exaggerates is that we can't just ignore
observations that we haven't been able to fit into either an old or a new theoretical
framework. Observations have to be taken seriously even if we don't have plausible
ways of explaining them.
Hoyle & other opponents of big bang cosmology have tried to develop theories
in which Arp's "discordant redshifts" would fit. A collection of challenges to
standard big bang cosmologies is F. Bertola et al (eds.), _New Ideas in
Cosmology_(Cambridge, 1988) - somewhat dated now because if anything the evidence for BB
theories is now stronger. The earlier debate about observations can be found in a
collection by Field, Arp, and Bahcall, _The Redshift Controversy_ (W.A. Benjamin, 1973).
As the latter date indicates, Arp has been fighting this battle for a long time.
> And in the case of Arp, it is an assumption that the galaxies are
> 'physically connected.' If they are simply overlain on top of each other
> along the same line of sight, one far away one relatively near, then one
> has no anomalies. If vastly different redshifts were the rule, why don't
> we see it in our own local galaxy cluster where the angular size is large?
Among other things we can look at the expected statistics of such overlaps - see
the above volume.
George L. Murphy
gmurphy@raex.com
http://web.raex.com/~gmurphy/