From: bobb@tekig1.PEN.TEK.COM (Robert W Bales)
Newsgroups: talk.origins
Subject: Response to Michael Simon, part 2
Date: 17 Dec 92 21:35:15 GMT


Continuing my response to Michael Simon

>> me

>>The reality is that I have given examples of processes which textbooks on
>>radioactive dating say can give wrong dates.

>All of which are processes that are RULED OUT in isochron methods.

No. The *theory* rules them out.  But observation always takes precedence
over theory.  For example, contaminatation is one of the processes which I
have been repeatedly told is ruled out.  Yet [3] cites contamination as a
possible source and [2] cites it as an actual source of isochron errors.

>In general, only two kinds of "processes" can call a radioactive dating into
>question: either the elements in the decay process in question are leached
>from, or else are intruded into the sample.

>Both things *can* indeed happen to geological samples.

Agreed.

>Isochron series arechosen because parent and daughter isotopes (along with
>nonradioactive, or differently radioactive other isotopes in the same rock)
>are subject to DIFFERENT chemical processes over geological time, and so any
>process that MIGHT corrupt one of the elements NECESSARILY operates on others
>with a different proportion

There is no restriction that just ONE process operate.  The isotope ratios
observed are the sum total of the effects of *every* process (which is
capable of changing the ratios) operating on *all* the elements.

> -- and the failure to produce an isochron witnesses this.

Except that isochrons have been produced is samples believe to be contami-
nated, disproving the theory that contamination will lead to failure to
produce an isochron.

Except that the method of displaying the data can produce the appearence of an
isochron even when the measurements .

>>The reality is that I have given examples which are known -- by old-
>>earth theorists -- to have given the wrong dates.

>Like for example the famous Hawaiian lavas and their Argon dates :-)?

Like, for example, moon rocks.  Like, for example, a Russian biotite [4]:

   assigned age(1) = 2,736,000 years by the uranium-thorium method
   assigned age(2) = 5,200,000 years by the potassium argon method

>Rocks that BY THEIR FORM evidently contain intrusions are unsuitable
>candidates.  YOUR citing this is a massively dishonest shell game,

It is neither dishonest nor a shell game.  I introduced this example a
numer of years ago.  As I remember, at the time there was no common acknow-
ledgement of Michael's statement above that geological processes can affect
dating.  The invarience of decay rates was held to be sufficient.  The
Hawaiian lavas show that this latter is not true, that the physical/chemical/
geological properties of the sample are important.  The characteristics of
the rocks, what the scientists thought, or what the predictions were are not
the issue here.  The facts are:

     The time of eruption of the lava was known.

     The lava was subjected to K-Ar techniques.

     The dates obtained from K-Ar techniques were different from the real
     dates by up to 7 orders of magnitude.

Since these are the statements I made, I was not dishonest in any way.

>in that the examples witness to the reliability of conscientious application
>of the standard methods of dating.

This is not so.  Whether you define "accurate" as I do to be "giving the
correct results on known values" or as others do to be "giving agreement
between independent trials," accurate measuresments are needed to witness to
the reliability of a measurement method.  Since these measurements gave
incorrect results, they do absolutely nothing to establish the reliability
of anything.

Now we get down to the heart of the matter:

>In any case, this is STILL avoiding the issue for which I took you to
>task: the existence of mulitple independent dating techniques that ALL
>point to 4+ billion years of rocks on earth,

When considering multiple dating techniques, you need to consider ALL
techniques, not just the subset that gives a particular result.  I am not
going to open up the complete subject in this posting (We can do it later if
need be), but ther are techniques which point to a much younger age.  For
exaple, I mentioned short-period comets in a somewhat recent posting.

Such techniques were rejected because of the presence of known or suspected
correction factors which could make the age older than measured. The point is,
the *magnitude* of the correction is unknown.  A 10% correction on a method
which gives a 50,000 age yields 55,000 years, NOT 4 billion years.

>and the fairly detailed layout of the history of our planet in that time.

A history which does not imply an ancient age.

   Bob Bales
   Tektronix, Inc.

I help Tektronix make their instruments. They don't help me make my opinions.
Newsgroups: talk.origins