Re: To John Harshman -- re Isochrons
- From: Zoe <muze10@xxxxxxx>
- Date: Thu, 23 Feb 2006 02:28:06 GMT
On 22 Feb 2006 08:58:20 -0800, "thissteve" <thissteve@xxxxxxxxx>
wrote:
Zoe wrote:
radiometric dating is not used for recent stuff, is it? Rb87/Sr87 has
a half life of 48.8 billion years. This method will not be used on
recent rock.
The reason radiometric dating fails on recent rocks is that you'll get
an age of "zero" on rocks that are young compared to the half life,
do you actually get an age of zero because radiometric dating has been
done and produced a zero age? Or do you assume that it will be a zero
age and therefore there is no sense in using the radiometric dating
method on recent rock?
even though they're still old to us. But according to your idea, we'd
rarely get _any_ zeroes.
you can get zeroes if all the daughter product has leaked out, as in a
gas like argon, right? That is why the resort to Rb87/Sr87/86
isochrons.
We only get zeroes if the isotopes mix.
which method are you talking about now? I've been talking about
Rubidium for the mixing problem, not Potassium to Argon.
Check out http://www.creationism.org/articles/swenson1.htm
A creationist dates recent rocks. The age he gets, _relative to the
half life of 1.5 billion years_, is essentially zero.
where does he says that he GETS an age of zero? I see he says, "It is
widely assumed that the radioisotope clock is set at zero and starts
ticking when igneous rock solidifies from a molten state." That's not
the same as saying, as you say, that he gets an age of zero. Also,
note that this is the Potassium-Argon method, which has its problems
of gas leakage.
Quote:
"Sample (Mt.St.Helens' new dome)
"Age" (in millions of years)
1. "Whole Rock" 0.35 ± 0.05
2. Feldspar, etc. 0.34 ± 0.06
3. Amphibole, etc. 0.9 ± 0.2
4. Pyroxene, etc. 1.7 ± 0.3
5. Pyroxene 2.8 ± 0.6
-------------------------------------------
"Figure 2. Potassium-argon "ages" for "whole rock" and mineral
concentrate samples from lava dome at Mount St. Helens.
"What can one observe about these results? First and foremost is
simply that they are wrong. A correct answer would have been "zero
argon" indicating that the sample was too young to date by this
method. Instead, the results ranged from 0.35-2.8 million years! Why
is this? A good possibility is that solidification of magma does not
reset the radioisotope clock to zero. Probably some argon-40 is
incorporated from the start into newly formed minerals giving the
"appearance" of great age. It should also be noted that there is poor
correspondence between the different samples, each taken from the same
rock."
End quote.
Note that he is addressing Potassium-Argon, not Rb37/Sr37/36. This
has nothing to do with mixing, which is my current question.
(He doesn't
think it's zero, because he's comparing the results to "human" time
rather than the half-life time.) How did the creationist get zero age?
please quote the area where he got zero age.
Because the isotopes mixed, and the "clock" was reset.
homogenous magma and mixing has to do with Rubidium-Strontium, not
with Potassium-Argon. Why are we talking about isotopes mixing in
connection with the Potassium-Argon method that is addressed in this
link?
He didn't get
any "window" to the age of the earth. Your idea that mixing is a
problem is falsified.
but your falsification was directed to the wrong target. What about
Rb37/Sr37?
.
- Follow-Ups:
- Re: To John Harshman -- re Isochrons
- From: thissteve
- Re: To John Harshman -- re Isochrons
- References:
- To John Harshman -- re Isochrons
- From: Zoe
- Re: To John Harshman -- re Isochrons
- From: rmcbane
- Re: To John Harshman -- re Isochrons
- From: Zoe
- To John Harshman -- re Isochrons
- Prev by Date: Re: Duck! It's Dick!
- Next by Date: Re: Upended quantum physics in the news
- Previous by thread: Re: To John Harshman -- re Isochrons
- Next by thread: Re: To John Harshman -- re Isochrons
- Index(es):
Relevant Pages
|
