Re: Reconsidering Halton Arp

Randy Poe <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> On Sun, 30 Nov 2003 11:13:10 -0800, "greywolf42"
> <[EMAIL PROTECTED]> wrote:
>
> >Randy Poe <[EMAIL PROTECTED]> wrote in message
> >news:[EMAIL PROTECTED]
> >> On Wed, 26 Nov 2003 11:13:12 -0800, "greywolf42"
> >> <[EMAIL PROTECTED]> wrote:
> >> >> 1) Measure redshift of object.
> >> >> 2) Measure distance to object.
> >> >
> >> >We can't measure distances directly beyond parallax range (about 300
> >> >parsecs).  The 'measurements' that we use beyond the nearest few dozen
> >> >galaxies (based mostly on cepheids) are all based squarely on assuming
> >the
> >> >big bang.
> >>
> >> Describe those methods and tell me where this assumption comes into
> >> the method, or stop repeating this ridiculous bit of nonsense.
> >
> >You can easily show me my error by describing (i.e. not just naming) one
> >method that does NOT use the big-bang assumption -- either directly or
> >indirectly (i.e. for calibration).
>
> Noted, for the record, that you made a blanket statement without any
> knowledge.

I have knowledge of several different methods of estimating distance.  But
they are all based directly or indirectly on assuming the hubble constant.
Obviously, you think you know one.  All it takes is one, to show me (and the
rest of the newsgroup) my error.  Go on!  Don't you want to provide
education?

> Now you want me to provide the actual information so you
> can try to find a place to claim your silliness applies.

I figured you couldn't provide any.

> >I simpy won't bother answering an open-ended question, from someone who
> >snips and ignores all prior evidence in the thread.  No matter how  many
> >methods I describe that do use the BB directly or for calibration, you
> >can always complain that I missed one.
>
> What does "use the Big Bang for calibration" even mean?

Every "standard candle" distance method requires a calibration step.  There
are methods used for distance estimation that are used beyond the range of
cepheids.  Look up the section entitled "secondary distance indicators" in
the book "The Cosmological Distance Ladder".   These are defined as " ...
indicators which depend for their calibration on our knowing the distance to
some representative nearby galaxies through primary distance indicators."

Taking the first method in that section -- for no other reason than it's
first in the book -- we have the "HII regions" method.  It is based on the
assumption that one can estimate the dimensions of core and halo diameters
within the HII regions of a galaxy (and that these surround new O and B
stars).  A 'correlation' was found between the HII region diameter and the
galaxy luminosity class.  There are several problems with this method
(including the fact that the relationship was not the one that was first
identied, but was 'forced' as a secondary method when the first was found to
be nearly useless), which are listed in the book.  The primary one being
that the method of core and halo diameters on the plates are subjective and
liable to systematic errors.  But this method was created by first ensuring
(via extinction and selection of the 'proper' definitions for intensity)
that the correlation (which has no theoretical justification) would be both
linear and consistent with the hubble law.

> Tell me that
> and I'll describe distance measurement via Cepheid variables. Found
> several good links.

I'm not interested in "links".  And I don't need to know about estimating
WITH cepheid variables.  I'm talking about distance measurments *beyond* the
distance where cepheid variables are resolvable.

--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}