creationism
Ray Ingles
(I sent this to him as a letter, too, just to make sure he gets it.)
>You do not have to chuck all you know about physics in order to establish
>creationism as the true origin of the earth.
Well, actually, *I* do. To be honest, you do not seem to know enough
about physics to judge.
>---------------------HIGH-PHYSICS DENSITY MATERIAL...------------------------
>Physics, fact, tells us the obvius- Uranium 238 decays by alpha radiation
>with half life of a couple billion years to 90-234 Thorium (I believe that's
>the element). It does not, repeat NOT say that Uranium decays to lead directly
>Suppose I make a rock out of 10%U-238 and 10% Th-234, that rock is about
>zero seconds old. Our wonderful dating techniques will say that it is a couple
>billion years old.
Actually, it wouldn't. See the post that follows this text.
> Case in point- A horn was carbon dated and "found" by
>Stanford University to be about 2500 years. It was transported, and dated
>the next year and found to be about 4000 years old. I guess they grew up
>slower back then. They also had a life span of about 1500 years. Boy they
>must have died old!!!
Are you getting this straight from the source, or was this reported to
you secondhand? I suspect the latter. When I first heard about this, I
was sufficiently curious about it that I looked it up where it was first
reported. It turns out that horn is a known problem material... you see,
it can abosrb carbon fromt he soil and thus appear younger than it really
is. What is not mentioned in the creationist sources that cite this is
that the younger date is from the outside of the horn, and the older date
is from the middle... which is only what you'd expect from chemistry.
In addition, one bad result doth not a theory destroy. Not only is this
result misrepresented (the authors of the paper specifically mentioned
that problems with horn and other materials, and specifically pointed
out the results that should not be trusted, even when they agreed with
what was expected) but it was in a paper with a few hundred other results
that agreed perfectly with traditional ages. Finally, the paper was from
the late 1950's, and used equipment that was far less precise than that
which is in use today. I have the paper copied in my desk at home; I can
give you the citation if you wish.
>Point number two- dating is Uranium lead. It's the ratio of lead
>to uranium. Nobody is going to tell me that there was no lead there in the
>first place. Anyone telling me that there will be no Th-234 or any other
>things that decay to lead in there!
In many minerals, yes, this is exactly the case. Their very chemistry
(which is something we can test today) precludes this. So, for many
materials, we can be quite confident of the results.
>------------------------------No more physics...----------------------
>Now will you throw out that physics to support stubborn evolutionist ideas?
>Of course not! Never! You evolutionists will remain as dogmatic as ever
>before.
Actually, I fail to see where *we* have been dogmatic...
>Really. Look at the facts. The facts are that we should not believe
>radioactive dating. The facts are shown above. Any problem with them?
You produced precisely one 'fact', which I believe has been thoroughly
discredited. The rest was opinion and 'arguments from incredulity' which
show that yuo have no background or expertise in minerology or
geochemistry.
In addition, you seem to have little knowledge of radiodating as it is
currently practiced. In the first place, carbon dating is accurate only
in the range of a few tens of thousands of years; it is laughable to
suppose that anyone would use it to date the Earth. As to the other
methods of radiodating (of which there are many more than you seem to be
aware) I think the post that I quote below explains why your objections
are without much basis.
Of course, the *real* problem is that there are *many* lines of evidence
besides radiotating which lead us to postulate an old Earth. For example,
we can samples of wood in which the rings overlap (that is, if one tree
was... uh... 'born' in 3000 B.C., and another was 'born' in 2950 B.C., then
there will be a region where the tree rings (which are large in good years,
and thin in lean years) will correspond. By finding many such samples, we
have put together an *unbroken* sequence going back over ten thousand
years, last I heard.
Of course, we have drilled samples of Antarctic ice, which have layers
corresponding to yearly snowfall. These go back over 100,000 years.
There is so much more (varves, erosion rates, and so many more I'm
forgetting) which *all* give dates for an old Earth, and all of them
*agree* with each other as best we can see. This smacks of more than
coincidence, I'm afraid.
Anyway, on to the Isochron FAQ, but Chris Stassen:
---------Begin Quoted Text--------
Subject: Isochron Dating Posting
Outline:
1. Generic Radiometric Dating
2. What's wrong with non-isochron dating methods?
3. Generic Isochron Dating
4. What's NOT wrong with isochron dating methods?
5. For further information (some things to read)
(1) Generic Radiometric Dating
Generally, radiometric dating is done by performing a simple
calculation on a sample, involving three measurements:
a) The first "measurement" is actually a "known quantity" -- the
half-life of the radioactive element used by the method. This
value can be experimentally measured in a lab -- but since many
experiments have failed to effect a noticeable change in the
rates relevant to radiometric dating, it is usually taken from a
table.
b) The second measurement is the amount of "parent" element (the
radioactive element used by the method).
c) The third measurement is the amount of "daughter" element (the
element that the radioactive one decays into).
Since each atom of the parent element decays into one atom of the
daughter element, we calculate that the original quantity of the
parent element is the sum of the current amounts of parent and
daughter elements. We then apply the following (frosh physics)
equation (the infamous "radioactive decay" equation):
P = P0 / (2 ^ (T / H) )
or P = (P + D) / (2 ^ (T / H) )
Where:
P is the current amount of parent element
P0 is the original amount of parent element (= P + D)
T is time that has passed ("age" of the sample)
H is the half-life of the element
Solving for T, we calculate the sample's age as:
T = H * log2 ( (P + D) / P)
(2) What's wrong with non-isochron dating methods?
Obviously, there are a few assumptions above which have been
made for the sake of a simple expanation, but which will not
always work in the real world. These include:
a) The amount of daughter element at the time of formation of the
sample is zero. Possible ways to avoid this problem include:
work on a mineral that can't incorporate any of the daughter
compound when it forms; somehow calculate the amount of initial
daughter product and subtract it out.
b) No parent element or daughter element has entered or left the
sample since its time of formation. Possible ways to avoid this
problem include: only date samples whose geological history does
not appear to include events which might cause this problem; date
several different parts of the same sample and only accept the
result if they all agree because contamination is not likely to
affect all parts of a large sample in the same way.
The invention of isochron methods solves both of these problems
at once! Read on...
(3) Generic Isochron Dating
Isochron dating requires a fourth measurement to be taken, which
is the amount of a _different_ isotope of the daughter element.
In addition, it requires that the second through fourth
measurements be taken from several different objects which all
formed from a common pool of materials. (Rocks which include
several different minerals are perfect for this.)
When any rock forms, minerals "choose" atoms for inclusion by
their _chemical_ properties. Since the two isotopes of the daughter
element have identical chemical properties, they will be mixed
evenly when the sample forms.
However, the parent element, with different properties,
will not be mixed evenly relative to the daughter elements. So,
at formation time, a sample would contain measurements like the
following:
Mineral No. Parent Daughter Isotope
--------- -------- -------- --------
1 4 gm 1 gm 2 gm
2 2 gm 4 gm 8 gm
3 6 gm 2 gm 4 gm
Note that (for this example) there is always twice as much of the
"isotope" as there is of the "daughter" in every mineral. Also
note that the ratio of "parent" element to either one of the
others varies (as the parent element has different chemical
properties). After one half-life's worth of time has passed, the
values will have changed (as half of the parent atoms in each
mineral will have decayed into daughter compounds):
Mineral No. Parent Daughter Isotope
--------- -------- -------- --------
1 2 gm 3 gm 2 gm
2 1 gm 5 gm 8 gm
3 3 gm 5 gm 4 gm
Note that half of the amount in the Parent column has been
taken away and added to the Daughter column for each mineral.
Also note that the Isotope column, since it doesn't decay and
isn't a decay product, doesn't change at all.
I can do some math here, but it's easier to see it on a graph.
The isochron graph is drawn by graphing D/I vs. P/I. The
first set of measurements results in:
D/I 1 -
|
|
|
- (2)................................(3)...........(1)
|
|
|
+-------------|-------------|-------------|-------------|
0 0.5 1 1.5 2
P/I
Note that all of the samples lie on a straight, flat line. This
is what we expect: they all have the same D/I ratio, and hence
the same Y-value.
Note that, if the sample were homogeneously distributed
with respect to parent and daughter, then all of the data points
fall on the same point and no line can be derived.
The graph for the second set of measurements is:
2 -
|
|
|
- .(1)
| ..
| ..(3)
| ...
D/I 1 - ...
| ..
| ..
| (2)
-
|
|
|
+-------------|-------------|-------------|-------------|
0 0.5 1 1.5 2
P/I
Once again, all the points lie on a straight line. And the slope
of the line is 1. (I know it doesn't look like it on the screen,
but that's because I used different units for X and Y -- you can
calculate it for yourself from the table above.)
We can make a simple table of slope of line versus age:
Slope Age
-------- -------------------
0 0
1 1 half-life
3 2 half-lives
7 3 half-lives
... ...
N log2( N + 1 ) half-lives
(4) What's NOT wrong with isochron dating methods?
Now that the mechanics of plotting an isochron have been
described, we will return to address the problems that were
mentioned before and describe why isochron methods don't fall
prey to them.
a) Initial daughter compound.
Any amount of initial daughter compound is compensated by the
isochron method. If one of the minerals happened to have none
of the parent element (the Y-intercept of the line), then its
amount of daughter compound wouldn't change over time -- because
it has no parent atoms to produce daughter atoms.
Regardless of whether there's a data point there or not,
the Y-intercept of the line doesn't change as the slope of the
line does. (You can verify this for yourself; the Y-intercept
of both lines above is 0.5.) The Y-intercept of the isochron
line actually gives the ratio of daughter to the other isotope
at the time of formation.
For each mineral, we can then measure the amount of the
other isotope and calculate the amount of daughter product that
was present when the sample formed. If we then subtract it out,
we could derive a "traditional" age for each mineral by the
equations described in the first section. Each such age would
match the result given by the isochron.
b) Random contamination (parent or daughter entering or leaving the
system)
For the sake of brevity, our example only included three data
points. While isochrons are performed with that few data points,
their value is not treated as seriously as those which have tens
of points.
Any non-systematic contamination is _extremely_ unlikely
to leave all of the data points on the line. Even in our little
example, any contamination of one of the minerals would require
a specific contamination of one of the other two in order to keep
all three points on the same line.
When we get to an isochron with tens of data points, the suggestion
that contamination "just happened to place the points on a (fake)
isochron line" can be discarded out of hand. It's too unlikely.
[Now, there is a form of isochron contamination, known as "mixing,"
which basically amounts to a _partial_ resetting of the isochron
clock. However, there are tests to detect it.]
c) General dating assumptions
All radiometric dating methods must assume certain initial
conditions and lack of contamination over time. The wonderful
property of isochron methods is that *if one of these assumptions
is violated*, it is nearly *certain* that the data will show that
by the points not plotting on a line.
(5) For further information, see:
G. Faure, _Principles of Isotope Geology_ (a textbook/handbook;
very technical, but very good.)
G. B. Dalrymple, _Radiometric Dating, Geologic Time, and the Age of
the Earth_ (Email Chris Stassen if you want a copy.)
A. N. Strahler, _Science and Earth History_, pp. 130-135
--------End Quoted Text-------
Sincerely,
Ray Ingles ing...@engin.umich.edu
"The meek can *have* the Earth. The rest of us are going to the
stars!" - Robert A. Heinlein
chu...@hardy.u.washington.edu
Subject: Re: How do you explain the dinosaurs?
Summary:
Expires:
References: <Feb.23.02.06....@athos.rutgers.edu>
Sender:
Followup-To:
Distribution:
Organization: University of Washington, Seattle
Keywords:
You do not have to chuck all you know about physics in order to establish
creationism as the true origin of the earth.
---------------------HIGH-PHYSICS DENSITY MATERIAL...------------------------
Physics, fact, tells us the obvius- Uranium 238 decays by alpha radiation
with half life of a couple billion years to 90-234 Thorium (I believe that's
the element). It does not, repeat NOT say that Uranium decays to lead directly
Suppose I make a rock out of 10%U-238 and 10% Th-234, that rock is about
zero seconds old. Our wonderful dating techniques will say that it is a couple
billion years old. Case in point- A horn was carbon dated and "found" by
Stanford University to be about 2500 years. It was transported, and dated
the next year and found to be about 4000 years old. I guess they grew up
slower back then. They also had a life span of about 1500 years. Boy they
must have died old!!!
Point number two- dating is Uranium lead. It's the ratio of lead
to uranium. Nobody is going to tell me that there was no lead there in the
first place. Anyone telling me that there will be no Th-234 or any other
things that decay to lead in there!
------------------------------No more physics...----------------------
Now will you throw out that physics to support stubborn evolutionist ideas?
Of course not! Never! You evolutionists will remain as dogmatic as ever
before.
Really. Look at the facts. The facts are that we should not believe
Andrew Solovay
>creationism as the true origin of the earth.
You just have to chuck the logic and the formulae. (You can keep the
buzzwords and the safety glasses.)
>Point number two- dating is Uranium lead. It's the ratio of lead
>to uranium. Nobody is going to tell me that there was no lead there in the
>first place. Anyone telling me that there will be no Th-234 or any other
>things that decay to lead in there!
Nobody is going to tell you? That's wrong, I will. Ahem: "There was no
lead in there in the first place." (I'd tell you the other things too,
if I could parse them...) That is, geologists assume that the vein was
originally pure uranium. This is a reasonable assumption, because
uranium is ~40% heavier than lead. In the original molten Earth, the
two metals would certainly have separated; they would not have cooled
in a mixed-up form. Thus, we can assume that any lead found mixed with
uranium is left over from decayed uranium.
Now, God could certainly have created the lead mixed in with the
Uranium. But if It did so, It created something that looks exactly
like what we'd expect pure uranium to look like, after 4.5 billion
years of decay. God could hardly be shocked if we decided that's
exactly what it was.
For that matter, God could have created the world ten minutes ago.
(But if that's true, God wrote your posting, not you; so why should I
argue with *you*?)
>Really. Look at the facts. The facts are that we should not believe
>radioactive dating. The facts are shown above. Any problem with them?
Just one: they're full of shit.
--
Andrew Solovay
"I am the Golux, the only Golux in the world,
and not a mere Device."
Dave Knapp
>zero seconds old. Our wonderful dating techniques will say that it is a couple
>billion years old.
This is a lie. A pretty boldfaced one, I might add.
>
>Really. Look at the facts. The facts are that we should not believe
>radioactive dating. The facts are shown above. Any problem with them?
Actually, last time I looked, lying was a sin. I certainly consider
it one. The fact of the matter is that you made an untrue statement above.
If you knew it was untrue when you made it, then you were lying. Now I have
no idea whether you were lying or whether you are grossly ignorant; either
way, you haven't exactly covered yourself (or God) with glory, now, have you?
So, since I am a Christian, yes, I _do_ have a problem with your "facts."
My problem is that your behavior has brought discredit on all Christians.
-- Dave
--
*-------------------------------------------------------------*
* David Knapp d...@imager.llnl.gov (510) 422-1023 *
* 98.7% of all statistics are made up. *
*-------------------------------------------------------------*
Mats Andtbacka
> Newsgroups: soc.religion.christian
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This drek got bounced from there, so you had to vent your
adrenaline by posting to an unmoderated group, right?
I can live with that. Hope you feel better now. Just don't do it again.
-------- -------- ---------- ---------
If you think I'm gonna be responsible for this crap, you're madder than I am.
"If I damned your point of view, could you turn the other cheek?" - G'n'R
===>The Truth is still the Truth, even if you choose to ignore it.<===
Daniel A Ashlock
chu...@hardy.u.washington.edu () writes:
[I suspect this is an unlabled foreward...]
> You do not have to chuck all you know about physics in order to establish
> creationism as the true origin of the earth.
*sigh*
Can't they think up a _new_ fallicy?
[irrelevant physical argument deleted]
> Now will you throw out that physics to support stubborn evolutionist ideas?
> Of course not! Never! You evolutionists will remain as dogmatic as ever
> before.
*snicker* They think they've proved something don't they?
> Really. Look at the facts. The facts are that we should not believe
> radioactive dating. The facts are shown above. Any problem with them?
Your fallacy is: "if a piece of support for the theory of evolution is
incorrect then the theory of creation must be correct as a result."
IF radioactive dating is wrong and IF that is enough to invalidate
evolution THEN creation "science" is just as big a pile of crap as it
ever was. Perhaphs you could find scientific evidence _for_ your theory
instead of trying to beat up other theories.
I will leave it to other t.o. inhabitants to check your physics but if
it is on a par with your logic the theory of evolution is safe from you.
Bill Hamilton
>In article <1nj528...@shelley.u.washington.edu> chu...@u.washington.edu writes:
>
>>You do not have to chuck all you know about physics in order to establish
>>creationism as the true origin of the earth.
>
> Well, actually, *I* do. To be honest, you do not seem to know enough
>about physics to judge.
>
>>zero seconds old. Our wonderful dating techniques will say that it is a couple
>>billion years old.
>
> Actually, it wouldn't. See the post that follows this text.
>
>>to uranium. Nobody is going to tell me that there was no lead there in the
>>first place. Anyone telling me that there will be no Th-234 or any other
>>things that decay to lead in there!
>
> In many minerals, yes, this is exactly the case. Their very chemistry
>(which is something we can test today) precludes this. So, for many
>materials, we can be quite confident of the results.
>
>
earth and Chris' excellent isochron dating post, I would like to add that
the attack of Young-Earth creationists on geology implies that geologists
are careless or perhaps even dishonest in their work. Geologists
use what appears to me (nonexpert - I'm a EE, not a geologist, but I can
read) to be a very careful set of qualification rules to determine
whether a sample is likely to give accurate dating results. The rules
are aimed at ensuring that no contamination of the sample could have
occurred, and they involve careful inspection for cracks and evidence of
erosion or deposition. I would expect that any creationist who desires
to prove that the methods of geology are flawed should be able to state
and critique each of these rules. One statement of the qualification rules
may be found in "Christianity and the Age of the Earth," by Davis Young,
Head of the Geology Department at Calvin College. I should add that
Davis Young is a Christian who has concluded from the geological record
that the earth is quite old - as old as the geologists say it is.
Another fact that the creationists conveniently neglect is the agreement
of many lines of evidence, which Ray touched on. Creationists try to
exploit disagreements when they exist, but even if the lines of evidence
don't agree exactly, they agree well enough to give high credibility to the
conventional estimates of the age of the earth. As Dan Ashlock observed
recently, even if you assume that every line of evidence has a 95% probability
of being totally bogus, the probability that they are all bogus is
(0.95)**100=0.006, assuming that there are 100 independent lines of evidence.
(I reproduced this from memory, Dan. Correct me if I got it wrong)
So a significant part of the creationists' attack on conventional science
implies that scientists are careless or dishonest. I don't believe
character assasination is a tactic Christians should be using, nor do
I believe that withholding and misrepresenting facts that are inconvenient
is a tactic Christians should be using. Those are two of the reasons why
I am not a creationist.
--------------------------------------------------------------------------------
Bill Hamilton |
GM NAO R&D Center ----+----
Vehicle Systems Research | Now faith is the assurance of things
Warren, MI 48090-9055 | hoped for, the conviction of things
(313) 986 1474 | not seen. Heb 11:1
--------------------------------------------------------------------------------
The chief end of man is to glorify God and enjoy Him forever
- The Westminster Shorter Catechism
John Brawley
c > From: chu...@hardy.u.washington.edu ()
c > Organization: University of Washington, Seattle
Re:
c > ---------------------HIGH-PHYSICS DENSITY
c > MATERIAL...------------------------
(...)
c > Now will you throw out that physics to support stubborn evolutionist
c > ideas?
c > Of course not! Never! You evolutionists will remain as dogmatic as
c > ever before.
c >
c > Really. Look at the facts. The facts are that we should not believe
c > radioactive dating. The facts are shown above. Any problem with them?
One "fact" is not "fact" (you have no evidence to support it)
To wit: The presence of lead-206 in zircons as they formed is
a nonfalsifiable hypothesis, therefore irrelevant, and certainly
not "fact." But let's bypass this and have you explain something:
In Dr. (hon.) Robert V. Gentry's "polonium radiohalo" hypothesis
for evidence of recent creation, he mentions that Polonium-only
haloes are found in the same mica samples as are fully-formed
Uranium radiohaloes, right next to them. Now, given that:
1) It takes about 500,000,000 (five hundred million) alpha
emissions to make enough damage for a clear, sharp halo to
form (Gentry, 1986), and;
2) A complete polonium halo can form from its radiogenic central
'polonium' particle in _well_ under 7,000 years, and;
3) A _Uranium_ halo, with all eight rings clear and present, takes
_much_ longer to form than this (Each atom-step in the decay chain
_must_ wait until the previous step is complete, for each invididual
atom). A total _vastly_ longer than 7,000 years is required, then;
Bearing in mind that the presence of lead has _nothing_whatsoever_
to do with the formation of alpha-particle-caused pleochroic haloes
in these biotite mica samples (with _both_ types of haloes present),
how do you account for the presence of necessarily very old
radiohaloes (the Uranium haloes) _right_next_to_ the possibly very
young _Polonium_ haloes?
Bear also in mind that it is _only_ the decay of the radioactives
that produces the haloes. Unless there's some way for you to
_demonstrate_ that radioactive decay rates were "different (vastly
faster) in the past," doesn't the presence of _both_ types of haloes
in the _same_ bit of biotite crystal indicate a _big_ problem for
creationist interpretations of earth geologic history?
Is it rational to propose that God put the polonium _particles_
in the crystal and let them decay, as is Gentry's claim, yet
_had_to_ have put _complete_, _already-decayed_ Uranium haloes in
the same places, right next to the other ones?
Please respond. (_Some_ creationist please respond!) I'm tired
of posting this conundrum and getting complete ignorance (no
response) in return.
J B
Internet Email: john.b...@p1.f9.n8012.z86.toadnet.org
FIDOnet... 1:100/435.1
TOADnet... 86:8012/9.1 PO Box 224, Eureka, MO, 63025-1134
"Sit down before fact like a little child..." --T.H.Huxley
Warren Vonroeschlaub
>Stanford University to be about 2500 years. It was transported, and dated
>the next year and found to be about 4000 years old. I guess they grew up
>slower back then. They also had a life span of about 1500 years. Boy they
>must have died old!!!
Argh, not the stupid Horn argument again. This is right up there with the
"living mollusk" claim.
Has anyone compiled a FAQ of all the "bozo" questions with the short (1 or 2
paragraph) responses to them? That way when some new creationist shows up, at
least they don't waste time with arguments like:
If population growth is basically exponential, then how come the Earth isn't
covered knee deep in people?
If humans are decended from apes, how come there are still apes?
I can't imagine how X could have evolved.
Evolution violates the 2nd law of thermodynamics.
A living mollusk was dated [big number] of years old.
How can evolution say all mutations are improvements?
The probability of life appearing by chance is 1 in [big number].
Y is much too complicated to have appeared by chance.
There is a famous X that doesn't believe in evolution, so it must be false.
and so on.
| __L__
-|- ___ Warren Kurt vonRoeschlaub
| | o | kv...@iastate.edu
|/ `---' Iowa State University
/| ___ Math Department
| |___| 400 Carver Hall
| |___| Ames, IA 50011
J _____
Ray Ingles
>In article <1nj528...@shelley.u.washington.edu> chu...@u.washington.edu writes:
>> Case in point- A horn was carbon dated and "found" by
>>Stanford University to be about 2500 years. It was transported, and dated
>>the next year and found to be about 4000 years old. I guess they grew up
>>slower back then. They also had a life span of about 1500 years. Boy they
>>must have died old!!!
>
> Are you getting this straight from the source, or was this reported to
>you secondhand? I suspect the latter. When I first heard about this, I
>was sufficiently curious about it that I looked it up where it was first
>reported.
Actually, my memory played a trick on me. The paper that I looked up
was about measurements at Yale, not Stanford. But it *was* a big list
of radiocarbon dates, and *did* note some anomalous ages for some antlers.
The reference is: _Science_, vol. 126, pg. 911. (November, *1957*)
Here are some details:
The creationist who put me on to this had copied the references from some
creationist tome and had never bothered to look them up. Besides the
Yale paper, he cited some anomalous results from a paper from the University
of Michigan. The UM paper was from _Science_, vol 124, pg. 664.
(October, 1956) This paper specifically mentions known problems. A quote:
"Some remarks of a general nature are in order concerning the kinds of errors
that may arise in four particular types of measurements: (i) those in which
the sample is derived from shell; (ii) those in which the sample is
derived from bone, tusk, or antler; (iii) those in which the raw material
contains roots; and (iv) those in which the sample is measured in the
form of carbon black." (Note that the UM paper dates from *before* the
Yale paper, so these types of errors were known when the Yale measurments
were taken.)
The UM paper then goes on to note that, of all these errors, only shell
works to make the sample appear older than it is; all the others make
the sample look younger than it really is. So creationists really can't
draw much solace from this.
Some specific explanations:
(i) Shell - "...in certain kinds of environment the shell does not get
built entirely of carbon that is in C-14 equilibrium with the atmosphere.
The conditions... are not sufficiently understood so that any assurance,
one way or another, can be given a priori concerning a given collected
sample... We include our shell dates in the following list, but do so
only with the qualifications given." [Ed. note - I don't know enough about
this subject to say if the state of the art has improved in this respect;
anyone want to address this?]
(ii) Bone, Tusk, and Antler - "These materials are porous and may accumulate
calcium carbonate from percolating water. Therefore, there are risks in
using carbon from the inorganic compounds... We have, in all cases except
where expressly stated, discarded the acid-soluble component of these
materials and have obtained our carbon samples from the organic residue."
The measurements in question (these are now from the Yale paper):
Type: Sample # Age
Antler, burned after acid washing Y-158 9540+-130
Acid-soluble fraction of antler Y-158-1 7060+-400
Acid-insoluble fraction of antler Y-158-2 10760+-250
Antler, burned after acid washing Y-159 9310+-260
Acid-soluble fraction of antler Y-159-1 5340+-200
Acid-insoluble fraction of antler Y-159-2 10320+-250
This, the Yale paper, goes on to state about the second sample: "The
date of the organic fraction seems entirely reasonable... but as long
as it rests on antler it must be treated with reserve."
Back to the UM paper. The last two listed errors are:
(iii) Intrusive roots - "In many of the charcoal and peat samples we have
processed, we have found the remains of small roots that have intruded,
supposedly, from plants or trees growing above the deposit. Such roots
have been removed as far as possible with tweezers. However, we have no
defense against roots which have intruded and which have become pulverized
or otherwise unrecognizable. We can only point out, again as a precaution,
that this is a source of error which is at present [Ed. note: In 1956.
Anyone know if it's gotten better?] beyond the control of the measuring
technique. When root remains are present, they will, of course, make the
sample appear to be younger than it really is."
(iv) Carbon Black Technique - "The technique that employs a carbon-black
sample is open to the possibility of contamination by airborne radioactives.
[...lengthy discussion of safeguards taken to minimize the danger...] We
have thought it worthwhile to explain in some detail what the character of
the error is likely to be when it does occur, and to say that its
direction is such that it makes the specimen appear to be yuonger than it
really is."
Based on this sort of thing, I think that the creationist parody of
radiocarbon dating as a lackadaisical pastime with few controls and much
fabrication is quite unfounded. These people are careful, honest, and
have thought of and safeguarded against possible errors the creationists
counldn't seem to understand.
Moreover, almost all of the possible errors make the samples look
*younger* than they ought to be. So, the ages given by radicarbon dating
can generally be taken as a *lower* bound on the age of a sample.
Finally, the errors discussed here apply *only* to radiocarbon dating.
Other forms of radiodating are admirably suited for isochron methods,
which Chris Stassen has adressed in detail.
Sincerely,
Raymond Ingles ing...@engin.umich.edu
"An apple every eight hours keeps three doctors away." - B. Kliban
Bruce C. Wright
> In article <1nj528...@shelley.u.washington.edu> chu...@u.washington.edu writes:
>>
>>You do not have to chuck all you know about physics in order to establish
>>creationism as the true origin of the earth.
>
> You just have to chuck the logic and the formulae. (You can keep the
> buzzwords and the safety glasses.)
>
>>Point number two- dating is Uranium lead. It's the ratio of lead
>>to uranium. Nobody is going to tell me that there was no lead there in the
>>first place. Anyone telling me that there will be no Th-234 or any other
>>things that decay to lead in there!
>
> Nobody is going to tell you? That's wrong, I will. Ahem: "There was no
> lead in there in the first place." (I'd tell you the other things too,
> if I could parse them...) That is, geologists assume that the vein was
> originally pure uranium. This is a reasonable assumption, because
> uranium is ~40% heavier than lead. In the original molten Earth, the
> two metals would certainly have separated; they would not have cooled
> in a mixed-up form. Thus, we can assume that any lead found mixed with
> uranium is left over from decayed uranium.
It's not quite so simple. Primordial lead has a different isotope
distribution from lead that is a result of radioactive decay (which
is generally only a couple of isotopes, corresponding to the isotopes
of the parent material that's being measured -- usually uranium in the
case of lead as the daughter material). The isotopes that are the
result of radioactive decay are usually rather rare in primordial lead.
So in fact there _could_ have been lead in the original material, and
the dating technique already takes this into account.
If the dating method is grossly wrong like this, it isn't because of
a simple flaw such as the one described above; it would almost have
to be the result of a systematic salting of the proper isotopes into
fossil beds by some superhuman Intelligence with a specific intent to
give a false appearance of great age. Whether this conception of God
deliberately creating misleading evidence is palatable as a religious
concept is an individual matter -- some Christians have embraced the
concept and others regard it as almost akin to heresy. Strictly from
a scientific viewpoint it is however much more defensible than the
so-called `scientific' Creationism.
Bruce C. Wright
Andrew Solovay
Thanks for the correction. I really *should* know better than to post
on subjects outside my field, but then, my field is medieval history,
so what am I doing here in the first place?
Anyway: Please see .sig immediately below...
--
Andrew M. Solovay
"I have been Foolish and Deluded,
and I am a Bear of No Brain at All." -- Pooh