Re: Big Bang or Big Splat?

Thanks for answering my questions, I've learned a lot so far!

I'm confused.  You said one problem was that we don't see younger
galaxies.  I'm saying you do see younger galaxies, and now you claim
that's the problem.

My question was a bit confused. I was saying that we see "younger" galaxies (in terms of when they were around), but that they don't appear to be "younger" necessarily (in terms of their formation).

No, I don't think it has enough precision to imply that.  If galaxies
form in sheets (like the surfaces of bubbles in foam), then you will see
strong peaks in red shift distributions, corresponding to surfaces that
are perpendicular to line of sight.  But at a scale equivalent to the
sizes of the "bubbles," the universe is still uniform and isotropic.
Take a look at the three-dimensional map created by Geller and Huchra.


I'll have to look into that.

Arp's own papers.  Much of my own work is in probability and statistics,
and he makes unsupportable assumptions to show that more galaxies than
expected are along the same line of sight but do not show approximately
the same red shift.  For instance, he assumes that galaxies in clusters
are independently and identically distributed; that is not supported by
physical considerations.


Very interesting.

Nobody really claims to know all about how it works.  But the BB is
mainstream theory because it does explain a lot very well.  It is possible
to interpret red shifts other than in terms of expansion and recession
speed, but it requires a lot of ad hoc assumptions.  Even the steady
state theory assumes the universe is expanding--it just didn't have a
beginning--and in order to explain the 3-kelvin background radiation,
current versions also assume that the universe is permeated with iron
atoms (albeit very sparsely).

There is a vast difference between saying that the BB is not complete
and that it contains errors (which is certainly true), and saying that
it is not even in principle the right idea.  The evidentiary bar is
much higher in the latter case than in the former, and I don't think
it has yet been hurdled.

I think my main beef is only having one model. If you have only one model, and everything is interpretted and thought of in terms of that one model, then the "academic inertia" becomes too great for new ideas. It's even possible to lapse into "epicycle-like" reasonings without even knowing it. I always keep in mind that new theories are often only espoused by a single person or a few at first. This means that the amount of research that goes into solving questions along those new lines will be dwarfed by the research that goes into solving questions along the traditional lines -- which may be the reason why more questions are in fact answered, not necessarily because the theory is better. Sometimes the way that problems are phrased is that for a less traditional model, any problems with the theory automatically "discredit" them, while the same level of problem in the currently popular theory is considered "an open theoretical research problem".

I don't know that this is happening here, I just know that it has happened before, which is why I try to keep an open eye to dissenters as a matter of habit :)

Jon
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