Originally posted by Yorzhik
john2001-
Basically you won't comment on it because it is an indefensible assertion. Gentry's claims were flat out wrong.
I guess you could take it that way, but you would be wrong. I simply don't defend them because I haven't studied it enough. He could be right for all I know, or he could be wrong.
Essentially Gentry misrepresented the origins of his specimens and was caught at it.
john2001-
Gentry doesn't have a challenge anymore,
because he did not show beyond a reasonable doubt that there were no fractures.
I don't think he would have to. If I ran a test that required distilled water, but the tests could be questioned if I did not, would I have to prove I used distilled water? One would know that any competent scientist can get distilled water, and Gentry claims that any competent scientists can use the method he did to detect cracks, and there were none in his samples. At that point, unless you can prove him wrong, your "reasonable doubt" is unreasonable.
1) Gentry's method is *not* sufficient to detect
all cracks that are present.
2) The natural cleavage planes are all
parallel to the direction he is splitting his
specimens, direct crack detection more
difficult.
3) Finally, the fact that, of all the minerals
in the world, those that have radiohalos
in them happen to be two of the minerals
(biotite and flourite) with the most well
developed cleavage planes, gives us
the clue that the most parsimonious
explanation likely has something to do
with the well developed cleavage.
john2001
Furthemore, it is not clear that it is even necessary that fractures be present. The minerals in question have well developed cleavage planes which can allow 222Rn to penetrate the crystals.
Then run the test and take pictures of the halo. I'd be willing to doubt Gentry if it is done.
What test do you propose? Make a radiohalo? That would be interesting. It may even be doable if you could get a sufficiently large flux of 222Rn.
john2001
As to your usage of the term "ignorant" in your reply, this is a disengenuos attempt to mischaracterize the criticisms of Gentry's as being mere ad hominem attacks, which they are not.
I'd say that the way Gentry's claims have been dealt with would make me tend to believe that his critics on this point are only interested in their philosophy, and not science. So, yes, I'd say the ad hominem label tends to fit.
Gentry had his day. He published a few papers in _Science_ on radiohalos and
his stuff even looked like a real mystery
for a short time. Part of the problem is
that Gentry did indeed demonstrate that
he is unfamiliar with certain aspects
of geology and geochemistry. Call
him ignorant, or call him dishonest.
The fact that Gentry is not a geoscientist
made him "ignorant". If he had been
a geoscientist, he would likely have
been called "dishonest" and never would
have worked in the field again.
john2001
It is up to the *proponents* of Gentry's instantaneous formation hypothesis to show to the scientific community, beyond any reasonble doubt that Po halos cannot form by the more conventional means such as those proposed by Colins.
I agree.
john2001 -
If a person proposes an extraordinary hypothesis, it is up to *them* to provide the necessary extraordinary evidence to back up that idea. In Gentry's case, his claims run counter to the results of the majority of the scientific results from the geosciences.
Really? He made a claim. It was questioned. He answered. And instead of evaluating the science in his answers, he was basically called ignorant or stupid without futher evalution.
Gentry made a claim and certain inconsistencies were revealed in
his method. Basically, his conclusions
disappeared at that moment.
He failed to make any comeback.
I say this because the "majority" don't have the scientific results you are claiming. They should do a few things if they were honest: use the latest method that insures there are no channels for 222Rn and see if they can find halos in that kind of sample. Find granites with channels for 222Rn and record the empirical results... do the pictures look the same?
Sorry, but the vast majority of scientific evidence---everything from deposition rates,
the sizes of crystals in igneous and metamorphic rocks, to radiometric dates---point to an old earth---4.5 billion
years old to be precise.
Indeed, it would be interesting to study radiohalos futher. No doubt these items
will be studied again in the future. However,
whatever Gentry has done, it has not
been to push scientific knowledge in
the direction of his conclusion. Indeed, it
is quite the reverse. Halo formation seems
to be another slow process.