From: throopw@sheol.UUCP (Wayne Throop)
Newsgroups: talk.origins
Subject: Re: Bales vs. Meritt on isochrons
Summary: equal confidence in all methods is not reasonable
Date: 09 Nov 92 01:49:42 GMT

: From: bobb@tekig1.PEN.TEK.COM (Robert W Bales)
: Message-ID: <7478@tekig7.PEN.TEK.COM>
: As I have pointed out, the processes [..not accounted for in Bales'
: estimates resulting in a young earth ..] aren't known.  Chris Stassen,
: who I think first brought them up and those who study them state that
: they are unknown. 

This is an oversimplification.  As I recall, Bob cited many methods,
such as helium escape, mineral build-up in the oceans, erosion rates,
and so on, which *DO* have *KNOWN* processes which would cause them to
give inaccuratly small age estimates.  Only a handful, such as the
short-term comet depletion rate, don't have observed error-producing
processes (eg: a capture of a long-period comet into a short-period
orbit hasn't been directly observed), and even those have very plausible
error-producing processes in theory, and even indirect evidence, such as
the statistical association of short-period comets with Jupiter, a very
plausible capture point. 

The key points:

  - most of Bob's estimation methods have known youth-biased inaccuracies
  - those that don't have plausible hypothesized youth-biased inaccuracies

: It is possible that the processes make the evidence for a young earth
: compatible with an old earth.  It is equally possible, as I have documented,
: that they don't.  Ignoring the second possibility is an error of the same kind
: as is ignoring the first possibility.

  - Bob has never supplied a plausible example of an old-biased inaccuracy
    for counting methods (eg: tree rings, ice cores, varves, etc) that
    yield results totally incompatible with earth ages less than
    hundreds of thousands of years

It is at best perverse to claim that earth ages in the tens of
thousands of years are compatible with the evidence we have.

: As my discussion at the start of the posting shows, to be a valid
: analogy, the buckets need to be "possibly-leaky," not "known-leaky." I'm
: not sure what this would be physically, but it is necessary logically. 

Ah.  That hole in the bucket with water coming out isn't evidence of
leakyness to Bob.  The water coming over the top of the "not known
overflown" bucket should not bias our judgement.  I see.

And the video tape we have of the last hour of constant rainfall should
not bias us against considering rainfall durations of only a few minutes. 
(This last being analogous to the counting methods that reach back
beyond 100000 years, of course.)

: A finding of rainfall duation *requires*  knowing the amount of
: water contributed to the bucket by the sprinklers.  

(Which is the analogy of a contaminated specimin.)

Sprinkler water is chlorinated.  We simply test the bucket for chlorine
content.  (Analogous to the slope-of-isochron contamination tests.)

: Wayne's scenerio does not include this information.  

Now it does.

:: Isochron dates provide a method of testing that the "bucket" was
:: empty at the start of "rainfall".
: This is the theory. If true, it is a consequence of the theory's being
: correct.  Therefore, it cannot logically be citied as a reason to believe
: that the theory is correct.

I'm not citing it as a reason to believe that the theory of the isochron
method is correct.  That stands on its own, and Bob has never supplied a
specific, plausible, error mechanism.  I'm citing it as a reason to
believe the *results* of specific isochron tests. 

:: 1.  There is no evidence that the "isochron bucket" is more accurate
::     than the others. 

There is such evidence.  First, evidence that radioactive decay rates
are essentially constant (as discussed in the sci.physics FAQ, for
example).  Second, the internal checks that would invalidate
contaminated samples.  Both of these are "evidence", and Bob's dating
counter-methods have neither rate nor contamination checks.  

:: 2.  The buckets said to be "leaky" and "overflown" are actually not
::     known to be so. 

Short of an airy philosophical debate on what it means for something
to be "known", this is pretty much meaningless.  The evidence is strong
for that bucket with water flowing out over the top to be overflown.
The evidence is strong for that bucket with the hole in it to be
leaky.  Sure, you can't *see* the water leaking out of that porous
bucket over there in the corner, but you have a certain amount of
confidence that the cardboard it is made out of allows leakage.

Now, in his recent postings on isochron errors, Bob has finally shown
examples of "pseudoisochrons", with errors in the direction he wants
them.  (Pseudoisochrons might well correspond to buckets potentially
(but not known to be) contaminated with chlorine (to beat the last gasp
out of the analogy).) But even so, he provides no explanation of either:

    - disagreement with "counting" methods for his prefered ages
    - explanation for the wide-spread consistency of isochron and
      other ages, as compared to the extreme *lack* of consistency
      among various of his young-results methods.
    - any mechanism for agreement of multiple isochrons in a 
      single rock sample

The point remains.  The age-estimating methods Bob advances are
inferior and do not deserve equal confidence in their results (as
compared to, say, isochron methods or counting methods) because
they have no internal checks, and have either observed or plausible
youth-biased error-producing processes associated with them.  

I am NOT saying that the estimation methods that yield results Bob
is more comfortable with should not be considered.  I'm saying that
they *HAVE* been considered, and been found wanting as compared to
more consistent, checkable methods.
--
Wayne Throop  ...!mcnc!dg-rtp!sheol!throopw
Newsgroups: talk.origins