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Old 05-25-2010, 05:00 PM   #942724  /  #26
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Dave Hawkins in full deflection mode....
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Secondly, I think it's important to focus on what the most critical issues are first, rather than pointing out this or that error which ultimately don't matter (for example, the temperature graph issue).
...

No Dave. That temperature graph error is minor and sure doesn't matter at all.
I think that Davie's referring to Humphreys' (et. al.) egregious and amateurish error in reading Harrison et. al.'s Figure 9 backward which, as several have proven, blows Humphreys' "uniformitarian model" out of the water. Davie can't stand to acknowledge such a show-stopper error by the supposed intellectual elite of YEC, so as you said he goes into full deflection mode.
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Old 05-25-2010, 05:32 PM   #942782  /  #27
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Secondly, I think it's important to focus on what the most critical issues are first, rather than pointing out this or that error which ultimately don't matter (for example, the temperature graph issue).

So what is the most important issue? My understanding is that it is the "leakiness of helium in zircons." Just how leaky is helium in zircons? That seems to be a good layman's way of framing the most important question. I had assumed that the answer was "very leaky" but I'm willing to consider your reasons for why you think this is not so. Be patient though ... it may take me some time.
Dave... the temperature effects the "leakiness" quite dramatically, so reading the TEMPERATURE graph backwards and assuming a temperature based on that backwards reading will throw off the "leakiness" assumption tremendously.


In other words, the fucking graph is CENTRAL TO THE ISSUE OF HOW LEAKY HELIUM IS!

We are dealing with that "most important issue" you keep saying we should deal with first... you just don't fucking understand it!
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Old 05-25-2010, 05:47 PM   #942808  /  #28
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Secondly, I think it's important to focus on what the most critical issues are first, rather than pointing out this or that error which ultimately don't matter (for example, the temperature graph issue).

So what is the most important issue? My understanding is that it is the "leakiness of helium in zircons." Just how leaky is helium in zircons? That seems to be a good layman's way of framing the most important question. I had assumed that the answer was "very leaky" but I'm willing to consider your reasons for why you think this is not so. Be patient though ... it may take me some time.
Dave... the temperature effects the "leakiness" quite dramatically, so reading the TEMPERATURE graph backwards and assuming a temperature based on that backwards reading will throw off the "leakiness" assumption tremendously.


In other words, the fucking graph is CENTRAL TO THE ISSUE OF HOW LEAKY HELIUM IS!

We are dealing with that "most important issue" you keep saying we should deal with first... you just don't fucking want to fucking understand it!
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Old 05-25-2010, 07:02 PM   #942950  /  #29
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Secondly, I think it's important to focus on what the most critical issues are first, rather than pointing out this or that error which ultimately don't matter (for example, the temperature graph issue).

So what is the most important issue? My understanding is that it is the "leakiness of helium in zircons." Just how leaky is helium in zircons? That seems to be a good layman's way of framing the most important question. I had assumed that the answer was "very leaky" but I'm willing to consider your reasons for why you think this is not so. Be patient though ... it may take me some time.
Dave... the temperature effects the "leakiness" quite dramatically, so reading the TEMPERATURE graph backwards and assuming a temperature based on that backwards reading will throw off the "leakiness" assumption tremendously.


In other words, the fucking graph is CENTRAL TO THE ISSUE OF HOW LEAKY HELIUM IS!

We are dealing with that "most important issue" you keep saying we should deal with first... you just don't fucking understand it!
Well, there's more than one graph involved. The graphs Dr. Loecholt posted, and what I think Davie-doodles is inquiring about, are graphs that show how leaky helium is as a function of temperature. Humphreys did not read one of those graphs backwards.

The graph that he did read backwards is a model of what the temperature at depth was at Fenton Hill in the immmediate past. Humphreys thought Fenton Hill was hotter in the immediate past than it is today, so he thought calculating the diffusion of helium atoms based on a simple model of constant temperature was justified. If Fenton Hill were indeed hotter in the immediate past than it is now and there were no other errors in Humphreys' model, then his constant temperature assumption may have been justified (depending on how long a time he thought that constant temperature existed). But he read the graph backwards; in fact Fenton Hill was cooler in the immediate past than it is today (Loechelt has produced a graph showing it was a lot cooler for a long time). Humphreys' central assumption in his "uniformitarian model" is false. His "uniformitarian model" is garbage.

But reading that graph backwards doesn't affect Humphreys' young-earth model, which (according to his calculations) is an excellent fit to the measured data. Loecholt's demonstration of serious problems with Humphreys' model of diffusion as a function of temperature affects and invalidates all of Humphreys' modeling, both "uniforrmitarian" and young-earth.

So even if Humphreys hadn't read the temperature-at-Fenton-Hill graph backwards, alll his analyses would still be wrong because his diffusion-rate-as-a-function-of-temperature graph is wrong. The backwards graph reading is only important because it shows how sloppy and amateurish his supposedly professional research is. Having checked the primary sources, I think Loecholt understated the case that proves Humphreys' error. I was shocked that anybody could make that mistake with even a cursory reading of the papers.

And don't get me started on the boundary conditions at the zircon-biotite interface. Loecholt ranks that as a minor error because it didn't have a large effect; I rank it as a huge error because it reveals fundamental dishonesty in the RATE group.

I guess Loechelt feels compelled to be politer than I am.
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Old 05-25-2010, 07:16 PM   #942977  /  #30
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...
So even if Humphreys hadn't read the temperature-at-Fenton-Hill graph backwards, alll his analyses would still be wrong because his diffusion-rate-as-a-function-of-temperature graph is wrong.
Heh.
So, in a sense, Dave is right.
It really doesn't matter that Humphreys read the graph backwards; even if he hadn't, his conclusions would still be completely wrong because of other mistakes he made.
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I was shocked that anybody could make that mistake with even a cursory reading of the papers.
Which mistake? The backwards temperature vs. time graph? Or the wrong diffusion-rate-as-a-function-of-temperature graph?
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Old 05-25-2010, 08:34 PM   #943112  /  #31
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Welcome Dr. Loechelt
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Old 05-25-2010, 08:48 PM   #943140  /  #32
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So even if Humphreys hadn't read the temperature-at-Fenton-Hill graph backwards, all his analyses would still be wrong because his diffusion-rate-as-a-function-of-temperature graph is wrong.
Heh.
So, in a sense, Dave is right.
It really doesn't matter that Humphreys read the graph backwards; even if he hadn't, his conclusions would still be completely wrong because of other mistakes he made.
True. The backwards reading is sufficient but not necessary to invalidate his "uniformitarian scenario". But it's a serious mistake that reveals a lot about the RATE group's capabilities.

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Quote:
I was shocked that anybody could make that mistake with even a cursory reading of the papers.
Which mistake? The backwards temperature vs. time graph? Or the wrong diffusion-rate-as-a-function-of-temperature graph?
The backwards temperature vs. time graph. He didn't read a diffusion-rate-as-a-function-of-temperature graph, he created one ... wrongly. He based it on data points that were a mixture of "tightly bound" and "loosely bound" helium release, assuming that the data points were indicative of "tightly bound" helium only.

In his paper Dr. Loechelt has demonstrated a diffusion-rate-as-a-function-of-temperature curve based on RATE's lab measurements, using a model of diffusion that accounts for both "tightly bound" and "loosely bound" helium as separate populations. In this thread he's demonstrated a diffusion-rate-as-a-function-of-temperature curve based on Reiners' data and a tightly-bound-only model like Humphreys, but using the data points that really are indicative of the "tightly bound" helium only, instead of discarding those measurements as Humphreys did. See his first image in the first post of this thread. Both those curves on the graph agree well with the measurements until the temperature gets low (towards the right of the graph) and the amounts of "tightly bound" and "loosely bond" helium released get to be comparable.

Since the total amount of "loosely bond" helium is very small compared to the total amount of "tightly bound" helium, either diffusion-rate-as-a-function-of-temperature curve can be used to model the Fenton Hill zircon data. See the second image in his first post. But Humphreys' diffusion-rate-as-a-function-of-temperature graph is wrong, and isn't useful for anything except YEC propaganda
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Old 05-26-2010, 12:38 AM   #943342  /  #33
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Heh.
So, in a sense, Dave is right.
It really doesn't matter that Humphreys read the graph backwards; even if he hadn't, his conclusions would still be completely wrong because of other mistakes he made.
Only one mistake is relevant here, of course - the mistake of starting with one's conclusions and forcing all data to fit them, ignoring what does not.

We can be as sure as this life permits that no matter HOW Humphries read the graph, his conclusions would not change. It didn't even matter what graph he read, or whether he read one at all. When you START with the answers, these things kind of don't make much difference.
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Old 05-26-2010, 02:28 AM   #943419  /  #34
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I know I have asked this before but I didn't get a good answer, can anyone tell me what the proper response is to the creationwiki article that claims that using a vaccuum does not matter here is a copy & paste job of the creationwiki entry

"About Humphreys using zircons in a vacuum, creationwiki seems to say that that would have little effect. I imagine they are wrong but can anyone tell em for sure? this is what they say:

Helium Diffusion Experiments Performed In A Vacuum

Estimated He diffusion rates for both Creation and Uniformitarian models, compared to measured He diffusion rates. Made from data on pages 45, 51 and 54 of Radioisotopes and the age of the Earth IIAccording to this claim, the results of Humphreys et al are invalid because the helium diffusion experiments were performed in a vacuum and not under the subsurface pressures found at Fenton Hill. The claim is that under pressure the diffusion rates would be decreased by several orders of magnitude.

Actually, Humphreys had already consider this problem, and after researching it, he found that in the case he was dealing with, the difference in pressure would affect the diffusion rates by less than 1%, placing it with in the margin of error.

This claim is based on argon diffusion experiments done under pressure in soft mica, but this does not match Humphreys experiments. Zircons are very hard and compress very little under pressure. Furthermore, argon is both an order of magnitude larger and heavier than helium, these factors would nearly eliminate any pressure effect under the conditions found at Fenton Hill.

Since the experiments were done using layered soft mica, under pressure the layers are easily squeezed together, reducing diffusion between the layers. Furthermore the pressure was supplied by water, and not the weight of overlaying rock. It turns out that the water not only supplied pressure, but it also gets between the layers of mica and chemically bonds with it, thereby reducing the diffusion rate considerably more. In fact, the water content of mica had far more of an affect on diffusion than pressure.

So the experiments on biotite mica without water showed a much lower change. At a pressure of 14 kilo bars, the diffusion was reduced by about two orders of magnitude. At a pressure of 1 kilo bar, the effect comes to about one order of magnitude. [10]

It is further suggested that under pressure defects in the zircon crystals would close, eliminating the defect bend. Not only is there no evidence to support this claim, but there is evidence against it. First of all, most of the defects in zircons are radiation damage that would not close under pressure. Second, original zircons used to predict the diffusion rates not only show a defect bend, but accurately predicted its location and slope, thus showing that defect bend did occur under pressure in situ."
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Old 05-26-2010, 06:18 AM   #943521  /  #35
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Well first of all, since you expressed concern to me about some of my postings, let me apologize publicly for being a little rough on you and for being a little hasty in asserting that you are wrong about various issues. I also want to make it clear that I don't think you are intentionally trying to deceive people ... it may have sounded like I did think this when I complained about the misleading temperature graph. I believe that we all should treat each other with respect and I think we all fail to do this at times.

Secondly, I think it's important to focus on what the most critical issues are first, rather than pointing out this or that error which ultimately don't matter (for example, the temperature graph issue).

So what is the most important issue? My understanding is that it is the "leakiness of helium in zircons." Just how leaky is helium in zircons? That seems to be a good layman's way of framing the most important question. I had assumed that the answer was "very leaky" but I'm willing to consider your reasons for why you think this is not so. Be patient though ... it may take me some time.
Dave,

Thank you for your kind and sincere words. I would like to see the debate be as civil as possible as well. Although I disagree with the young-earth position, the debate has actually sharpened my understanding of science by asking questions I would not have asked before and challenging assumptions that I used to take for granted.


Everyone,

I guess this is my welcome.

Thanks for the greetings and for noticing my work. It was sitting a long time on the web without getting much response. Even Humphreys ignores my work. His article earlier this year in the Journal of Creation is titled "Critics of helium evidence for a young world now seem silent". I am glad that there is a forum where ideas like this can be discussed. My endeavor is to be humble enough to learn from others, and to be patient enough to teach others. I spent a lot of time over the weekend getting caught up on the blog, and look forward to getting to know some of you better. JonF, I would in particular like to know a little bit about your background. You seem to grasp these diffusion issues quite well.
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Old 05-26-2010, 06:53 AM   #943525  /  #36
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!. Welcoming "Loechelt". Hi, good to meet you!

2. Reminding Dave Hawkins that many of us hold rather strongly that the right to respect has to be maintained - at least by being honest and, by actually answering questions posed, by showing that one has at least taken the trouble carefully to read the posts of others, and the relevant information they link to.

It is NOT honest continually to be claiming one has "evidence" for this or that position, when one is completely unable to produce, or even link to, said evidence, no matter how many times, and in what manner, one is asked to do so.
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Old 05-26-2010, 07:16 AM   #943526  /  #37
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So what is the most important issue? My understanding is that it is the "leakiness of helium in zircons." Just how leaky is helium in zircons? That seems to be a good layman's way of framing the most important question. I had assumed that the answer was "very leaky" but I'm willing to consider your reasons for why you think this is not so. Be patient though ... it may take me some time.
It is getting late, so I will have to keep this short. True, the "leakiness of helium in zircons" is the central issue. The physical sciences are a qunatitative endeavor, which is why they involve so much math. Let me use heat as an example. You can talk about things being "hot" or "cold" and have an intutive idea of what that means. A scientist, however, will want to quantify it and give it a number, called temperature in this case, which can be measured with a thermometer. When you talk about quantifying "leakiness", the quantity of interest is called diffusivity. Unfortunately, there is no such thing as a diffusometer. How then does one measure leakiness?

One idea would be to measure something that leaks. Put the sample in a vacuum, heat it up, and detect whatever comes out. That is the essence of a diffusion experiment. However, the case of helium diffusion in zircon poses a practical problem. We both agree that the earth must be at least 6,000 years old, right? However, to do an exhaustive diffusion experiment of helium in zircon, one would have to put the sample in the diffusion detector at the temperature of interest for ~6,000 years (minimum) and wait. No one is going to do this experiment.

What is the solution? Use statistics. In this case, it is the branch of physics called statistical mechanics, which deals with how heat affects things at the atomic level. If you put the sample in a chamber and heat it over various temperature, you can potentially extract a lot of information. In the case of the RATE diffusion experiment, if you look at the gas emitted in the temperature range of the rocks in the ground (i.e. below 250 C), you will find that it amounted to only a few parts-per-million of the total amount of helium present in the sample. What does that tell you about the diffusivity or "leakiness" of the rest of the helium? Very little, actually. Even though the temperature is in the range of interest, the statistical sample size of a few parts-per-million is too small to be an accurate indication of the leakiness of the other 99.999% of gas remaining in the sample. However, if you take the sample up to higher temperatures, you can get the helium to leak out faster, about 26% of the total amount in the case of the RATE experiment. With a sample size of 26%, you can now make a better statistical prediction of the leakiness of the remaining 74% of helium in the sample. The problem now is that you accurately know the diffusivity or leakiness at a temperature that is higher than the temperature of interest.

Statistical mechanics tells us that if the diffusion mechanism is simple, then you can extrapolate the result to a lower temperature by looking at the straight line on an Arrhenius plot, which is a graph of the log of the diffusivity versus the inverse of the temperature. (I know it may sounds strange to you, but the science behind it is very sound.) Here is the Arrhenius plot from the RATE experiment.



Notice that the straight line extrapolation of the high temperature data, which represents the leakiness of 99.999% of the helium in the sample, falls well below the low temperature data, which represents the leakiness of only 0.001% of the helium in the sample. The statistics of the experiment say that you should put more weight into the extrapolated leakiness of the majority, and not the leakiness of the minority. Farley, Reiners, and company (whom Humphreys considers to be experts) determine the diffusivity by extrapolating from the high temperature data. Humphreys and company relied only on the low temperature data. Here is where their error lies. If you don't believe that Farley and company ignore the low temperature data, then consider why Reiners, in his 2004 paper, never even bothered to take his samples below 300 C!
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Old 05-26-2010, 08:38 AM   #943536  /  #38
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For anyone who wants to know why on earth you plot the log of the diffusivity against the inverse of the temperature, it is because of the use of the Arrhenius equation:

http://en.wikipedia.org/wiki/Arrhenius_equation
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Old 05-26-2010, 01:13 PM   #943598  /  #39
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For anyone who wants to know why on earth you plot the log of the diffusivity against the inverse of the temperature, it is because of the use of the Arrhenius equation:

http://en.wikipedia.org/wiki/Arrhenius_equation
No!!

It's Magik!!!


ETA: Wait a minute JB. The EAC used the Arrhenius equation to argue for oil taking millions of years to form. We can't use the same equation to argue diffusivity. That would be cheating or something.
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Old 05-26-2010, 01:54 PM   #943630  /  #40
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For anyone who wants to know why on earth you plot the log of the diffusivity against the inverse of the temperature, it is because of the use of the Arrhenius equation:

http://en.wikipedia.org/wiki/Arrhenius_equation
I would say it's because you get nice straight lines on the plot, which are much easier to interpret than fancy-dancy curves.

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Old 05-26-2010, 02:00 PM   #943636  /  #41
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For anyone who wants to know why on earth you plot the log of the diffusivity against the inverse of the temperature, it is because of the use of the Arrhenius equation:

http://en.wikipedia.org/wiki/Arrhenius_equation
I would say it's becasue you get nice straighlt lines on the plot, which are much easier to interpret than fance-dancy curves.
yup. there is a linear relationship between the log of the diffusion and the inverse of the temperature.
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Old 05-26-2010, 02:02 PM   #943638  /  #42
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JonF, I would in particular like to know a little bit about your background. You seem to grasp these diffusion issues quite well.
Thanks. I get some of it and miss some of it. I don't get the eigenvector stuff, I would have thought some Runge-Kutta variant would be good. Or would that have too much accumulated error? I'm still learning.

I have a BSME and MSME from MIT. As an undergraduate I did some numerical methods research in stress/strain analysis, using a technique that was basically the inverse of finite elements, sort of finding a set of Green's functions along an object's boundary that satisfied the boundary conditions and continuity and constitutive conditions. Much easier than finite elements for teeny cracks in infinite or semi-infinite bodies because you could apply boundary conditons at infinity. My graduate work was studying wear from a point of view of dislocation dynamics, using the program from my undergraduate work and some experimentation. (A few years later I went to a conference at which someone presented a paper about how I got it all wrong).

I spent 30+ years designing and supervising the design of capital equipment for the semiconductor industry. Nothing for the diffusion bay, except some cassette-to-quartz-to-cassette transfer equipment. Mostly stockers and interbay and intrabay transport and some surface metrology for epi wafers. I designed the open-cassette conveyer transport system for Infineon (at the time, Siemens) Module 1 and Module 2 in Dresden, and developed some pretty sophisticated AutoCAD-database links to keep track of all sorts of related stuff. I was on the SEMI 300mm pod design subcomittee with Gary Gallagher of Empak and Bill Fosnight of Asyst Technologies and a bunch of others. In 30+ years I picked up a little process knowledge. But the industry ain't fun anymore, small companies can't keep up. So now I do outsourced IT for small companies and in-home computer repair.

I always worked for small companies you're never heard of, with the possible exception of Asyst Automation, a now-defunct subsidiary of Asyst Technologies.
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Old 05-26-2010, 02:04 PM   #943643  /  #43
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wow, you must be really old.
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Old 05-26-2010, 02:35 PM   #943689  /  #44
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I know I have asked this before but I didn't get a good answer, can anyone tell me what the proper response is to the creationwiki article that claims that using a vaccuum does not matter here is a copy & paste job of the creationwiki entry

"About Humphreys using zircons in a vacuum, creationwiki seems to say that that would have little effect. I imagine they are wrong but can anyone tell em for sure? this is what they say:

Helium Diffusion Experiments Performed In A Vacuum

Estimated He diffusion rates for both Creation and Uniformitarian models, compared to measured He diffusion rates. Made from data on pages 45, 51 and 54 of Radioisotopes and the age of the Earth IIAccording to this claim, the results of Humphreys et al are invalid because the helium diffusion experiments were performed in a vacuum and not under the subsurface pressures found at Fenton Hill. The claim is that under pressure the diffusion rates would be decreased by several orders of magnitude.

Actually, Humphreys had already consider this problem, and after researching it, he found that in the case he was dealing with, the difference in pressure would affect the diffusion rates by less than 1%, placing it with in the margin of error.

This claim is based on argon diffusion experiments done under pressure in soft mica, but this does not match Humphreys experiments. Zircons are very hard and compress very little under pressure. Furthermore, argon is both an order of magnitude larger and heavier than helium, these factors would nearly eliminate any pressure effect under the conditions found at Fenton Hill.

Since the experiments were done using layered soft mica, under pressure the layers are easily squeezed together, reducing diffusion between the layers. Furthermore the pressure was supplied by water, and not the weight of overlaying rock. It turns out that the water not only supplied pressure, but it also gets between the layers of mica and chemically bonds with it, thereby reducing the diffusion rate considerably more. In fact, the water content of mica had far more of an affect on diffusion than pressure.

So the experiments on biotite mica without water showed a much lower change. At a pressure of 14 kilo bars, the diffusion was reduced by about two orders of magnitude. At a pressure of 1 kilo bar, the effect comes to about one order of magnitude. [10]

It is further suggested that under pressure defects in the zircon crystals would close, eliminating the defect bend. Not only is there no evidence to support this claim, but there is evidence against it. First of all, most of the defects in zircons are radiation damage that would not close under pressure. Second, original zircons used to predict the diffusion rates not only show a defect bend, but accurately predicted its location and slope, thus showing that defect bend did occur under pressure in situ."
It appears that Dr. Henke, a geologist, is not a diffusion expert as Dr. Loechelt is.

The effects of pressure in the field may or may not be important

All the stuff about mica is basically arm-waving. Nowhere is there any data supporting a quantitative equivalence between zircons under pressure and mica under pressure. Mica certainly is quite physically different from zircon.

It does seem that lab diffusion experiments under vacuum are standard and justified. So I think that there's no need to do the experiments at pressure.

The "defect bend" is where the amounts of "tightly bound" and "loosely bound" helium released become comparable and then the "tightly bound" helium release essentially disappears. Dr. Loechelt has demonstrated, in several ways and quantitatively, that the amount of "loosely bound" helium (and therefore the "defect bend") is insignificatn and may be ignored.

I don't know about Humphreys' prediction of the location of the "defect bend". I have the paper but I can't access it right now, and Dr. Loechelt might have some comment.
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Old 05-26-2010, 02:37 PM   #943691  /  #45
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wow, you must be really old.
Yeah, I forgot to mention that I saved the world for democracy in Vietnam.







You're welcome.
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Old 05-26-2010, 03:09 PM   #943723  /  #46
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wow, you must be really old.
Yeah, I forgot to mention that I saved the world for democracy in Vietnam.
younger than I thought though
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thanks very much
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Old 05-26-2010, 03:29 PM   #943741  /  #47
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You might not be that old. After all, Dave assures us that non-biblical dating techniques are unreliable.

Just to be sure, Dr Humphries here will grind you up and heat you in a vaccuum . . .
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Old 05-26-2010, 03:35 PM   #943749  /  #48
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The "defect bend" is where the amounts of "tightly bound" and "loosely bound" helium released become comparable and then the "tightly bound" helium release essentially disappears. Dr. Loechelt has demonstrated, in several ways and quantitatively, that the amount of "loosely bound" helium (and therefore the "defect bend") is insignificatn and may be ignored.....
This is where it gets a little confusing, because it sounds like the bottom line is that a single-domain model would be OK after all - since the neglected additional domain(s) is (are) indeed negligible.

I wonder if JonF &/or Dr. Loechelt can make enough sense of this question to offer an answer?
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Old 05-26-2010, 08:11 PM   #944118  /  #49
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The "defect bend" is where the amounts of "tightly bound" and "loosely bound" helium released become comparable and then the "tightly bound" helium release essentially disappears. Dr. Loechelt has demonstrated, in several ways and quantitatively, that the amount of "loosely bound" helium (and therefore the "defect bend") is insignificatn and may be ignored.....
This is where it gets a little confusing, because it sounds like the bottom line is that a single-domain model would be OK after all - since the neglected additional domain(s) is (are) indeed negligible.

I wonder if JonF &/or Dr. Loechelt can make enough sense of this question to offer an answer?
I think the argument is that a single diffusion model is adequate if one disregards the initial release of Helium during the heating ramp (because that's when the majority of the loosely bound Helium is released). Humphreys got it wrong by including the Helium released at lower temperatures.
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Old 05-26-2010, 08:31 PM   #944140  /  #50
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I think the argument is that a single diffusion model is adequate if one disregards the initial release of Helium during the heating ramp (because that's when the majority of the loosely bound Helium is released). Humphreys got it wrong by including the Helium released at lower temperatures.
Well, Humphreys thinks he's answered these concerns because he did not include the helium released in the first 9 steps (up to 450˚C):
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Loechelt is right in claim (A), but wrong in claim (B). He overlooked part of one of his own quotes, in which an expert pointed out that loose helium would only affect the initial steps of the laboratory measurement, because after the initial steps the loose helium would be gone. That is one reason diffusion experts recommend ignoring the initial steps. Our experimenter recommended that, and that is exactly what we did.35 Thus he felt free to tell us that the rates he measured were accurate depictions of the leakiness for the other 98% of the helium. Ironically, our expert is one of those that Loechelt cites in his section about this issue. Loechelt either completely misunderstood the experts, or he deliberately distorted their meaning.
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