JonF
Posts: 634
Joined: Feb. 2005
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| Quote (afdave @ June 06 2006,22:48) | | You are correct about the exponential scale ... I wasn't looking at the graph and forgot momentarily that it was not a linear scale ...But here's the important thing to know about temps ... COLD TEMPS DON'T MATTER (unless you are talking about sub-zero or something ... Surely you are not foolish enough to say that) ... Go on and pick some reasonably cool temperature ... It will help you very little ... |
Dave, all temperatures matter, and time matters too. Let's see your integration of temperature effects over time that shows "It will help you very little". Of course, you are just making it up; you (and Humphreys) have no relevant calculations.
You seem stuck on the idea that we're looking for one and only one error in Humphreys' results, and that one error must explain all the anomaly. Not so. There are many possibilities for error, maybe some nobody's though of yet, and the goal should be to arrive at the truth rather than push anybody's ideological agenda (as Humphreys' explicitly admitted is the goial of the RATE project, in the quotes I posted already). Maybe some of the anomaly is from incorrect temperature assumptions, some from incorrect diffusion rate assumptions, some from incorrect calcualtionso of Q/Q0, some from ... you should, but probably don't, get the idea.
| Quote | | You need 5 ORDERS OF MAGNITUDE, and there is no way to get it |
This betrays your ideological point of view. What we need to do is figure out what's going on with those zircons, if it's at all possible given today's technology and abilities. That means formulating hypotheses and testing them. The hypothesis that the zircons and the Earth are circa 6,000 years old is incredibly far down on the list of possibilities and ... guess what ... as long as you're invoking magic in that hypothesis, it's not testable and doesn't even belong on the list. I note you ignored my proof that Humphreys' explanation is "magic".
| Quote | | ... Also, your sources report that there was volcanic activity and a large temp spike ... This negates any benefit your argument might have gained from low temps before this. |
Show your calculations. You need to integrate temperatures over times. A long time at a relatively low temperature can more than offset a short time at a relatively high temperature. I don't know the temperature history of the zircons to be able to do a meaningful calculation; but you claim to. Let's see the numbers.
| Quote | | You need to read all the relevant documents of this debate ... You didn't even read Humphreys' rebuttal about the vacuum testing ... If you did, you should know that it is DOA. |
I read it. No data. Just hand-waving.
| Quote | | As for reverse contamination of the zircons, I guess 'Davey-poo' the lowly engineer will have to point out AGAIN that helium doesn't diffuse from LOW pressure to HIGH pressure ... especially when you are talking about 1/200th of the pressure. |
It's not pressure, Davey-poo, it's concentration. And Davey-poo is still assuming today's conditions without justification. And Davey-poo the illiterate engineer has failed yet again to read what I explitly wrote:
"Diffusion consists of a species moving from an area of high concentration to an area of low concentration. If the helium concentration outside the zircon is higher than inside, helium flows in. And, of course, the rate at which helium flows in or out depends on the concentrations in the two areas; if there was unaccounted-for helium outside the zircons the diffusion rate calculations are wrong, no matter which direction helium was moving.
We're dealing with very small amounts of helium ... it wouldn't take much "reverse diffusion" to totally bollix the results. Helium is found in boreholes a few kilometers away. Helium is a tiny molecule and moves through very small spaces very easily."
I explicitly stated that it would take higher concentration of helium outside than inside for "reverse diffusion" to take place ... but any change in the amount of helium outside is going to change the diffusion. Where's your data relevant to the concentraion of helium over time outside those zircons?
Gosharootie, Humphreys may be right on some of these items; but he needs to establish that he's right with data, not arm-waving. Until and unless he does, errors in diffusion rates is a viable hypothesis for some if not all of the anomaly.
| Quote | | You are reaching and you should know it. Henke's rebuttals didn't have a prayer against Humphreys. I'd be willing to bet that very few here at ATBC even understand the issues here, much less have the ability to refute the results. This explains why some people resort to mudslinging because they have very little of substance to say. |
True. You obviously don't understand, and you haven't posted anything of substance.
| Quote | Let me rehash the RATE Helium results.
1) Creationists have observed that the 4 leading methods of long age radioisotope dating almost never agree with each other. They are generally VERY discordant. They should agree if they are reliable. |
Not a RATE result .. in fact, not a result at all, but another blatant lie. Different radiometric methods almost always yield concordant dates, so often so that there's no interest in mainstream science in quantifying the amount of agreeement; it would be like proposing a study to see how often Google Maps and Mapquest show the same street in the same place. Discordant dates arouse interest, but there's mighty few of them. Some creationists have come up with a very few individual instances in which one dating method gave supposedly wrong results; subtract the miscomprehensions (e.g. Austin's Grand Canyon isochron) and outright frauds (e.g. Snelling's Mt. Ngauruhoe study) and you've not even got a handful of results, none of which are about concordancy with other methods. The closest creationists have come is Woodmorappe's list of 400 discordant dates, some of which are discordant with stratigraphy and not other radiometric methods, and which is discussed at Young-Earth Arguments: A Second Look and Reply to Woodmorappe's Critique of My Web Page. But, even if one takes all 400 dates as relevant to Davie's claim, 400 is a minuscule number; far, far les than 1% of all radiometric dates. So, Davie-poo, let's see the statistcs to back up this claim that "the 4 leading methods of long age radioisotope dating almost never agree with each other".
For those few readers who might actually be interested in this subject, some discussion of concordant dates is at Radiometeric Dating Does Work! (the He11 Creek results are especially interesting, because that's where the Tyrannosaurous was found in which Schweitzer found interestly preserved structures inside the bone ... but I digress), and Consistent Radiometric dates. Of course, there's lots more.
It is not unusual for radiometric dates to be very slightly discordant, because different methods are actually measuring slightly different things; the point at which the rock cooled enough to "freeze" the relevant atoms, and this point is different for different atoms. This fact is commonly used in cooling of structures such as plutons that cooled slowl.
| Quote | | 2) Many other non-radiometric indicators support a very young earth ... On the order of thousands, not billions of years |
None of these alleged indicators have stood up to cursory investigation.
| Quote | | 4) Science needs more reliable dating methods since radioisotope dating is unreliable. |
Basically the same claim as #1, and wrong for the same reasons.
| Quote | | 5) Helium diffusion from zircons is a good candidate if the rocks are relatively cool, because a high percentage of helium is retained. |
Pretty much true. Now all you need to do is provide justification fer the assumptions in this particular case.
| Quote | | 6) No one had measured He diffusion in zircons before (why? Afraid of the answer maybe?) |
Another blatant lie, and one that's already been refuted in this thread. Dave, do you think we so stupid we can't remember what's been written already? The evidence suggests that you're that stupid ... I've already pointed out in this thread that mainstream scientists have been and are using helium dating in zircons. From the very Yale page you supposedly read, 'cause you quoted it:
"Much of the most exciting work however, comes in figuring out new ways to use He dating, such as how to date other types of minerals (e.g., garnet, zircon, etc.), using crystal-size-age relationships to elucidate extremely low-T (40-70° C) thermal histories of rocks, and applying He dating to novel problems."
Note that at Zircon (U-Th)/He Chronometry there's links to presentations as early as 2001 (which 2001 presentation addresses the issue of diffusion in zircons directly). So, nobody's afraid of the answer except creationists like Dave, who have nothing but lies.
| Quote | | 7) Humphreys' group published predictions for the rates at various temps and were DEAD ON when the measured rates came back from the lab 3 years later, a TRULY REMARKABLE FEAT. |
Yet, when someone else does the calculations, the results are WAY OFF. Obviously, somebody's assumptions are wrong. And it't the RATE group that defends their assumptions only with arm-waving. There's not enough information available to charge anyone with dishonesty, but I note that RATE has not released the raw data as requested; it's standard practice to make raw data available after you've done your analysis and publication. At Young-Earth Creationist Helium Diffusion "Dates": Fallacies Based on Bad Assumptions and Questionable Data in the "UNRELIABLE DATA IN HUMPHREYS ET AL. (2003a, 2004)" section:
"Dr. Humphreys has yet to reveal how these "typographic errors" in Gentry et al. (1982a) were discovered, whether any of the original laboratory notes were consulted to properly correct the errors, and why the errors went publicly unnoticed for about 20 years. As discussed above, there are numerous incidences where Dr. Humphreys has unjustly manipulated (e.g., a graph in Magomedov, 1970) or sloppily handled data (e.g., the units of measure in Appendix C of Humphreys et al., 2003a). Therefore, documenting the validity of the changes to the helium values from Gentry et al. (1982a) is even more urgent. Dr. Humphreys needs to fully explain this issue and dispel any possible thoughts that the data from Gentry et al. (1982a) were altered (like the data in Magomedov, 1970) to comply with his results. Finally, such poor documentation to justify changes in published data would never be tolerated in authentic scientific journals. Any editor or peer-reviewer of a legitimate scientific journal would demand a thorough and complete explanation of why these changes are justified before any revisions would be allowed to appear in their journals. Competent editors and reviewers would also insist that the original laboratory notes be consulted or that the results be discarded and the analyses redone. ...
Gentry et al. (1982a) does not contain adequate information on the lengths and widths of their zircons. Humphreys et al. (2003a, 2004) also failed to provide suitable measurements of the lengths and widths of the zircons and biotites in their samples. This information is needed to estimate the effective radii of zircons (a) and biotites (b), which are required for the "dating" equations in Humphreys et al. (2003a). ...
I need to remind Dr. Humphreys that his papers only contain one average b value (p. 8, Humphreys et al., 2003a). Contrary to the claims in Humphreys (2005), the necessary raw data to calculate a standard deviation for b are not present in any of his documents. How can anyone obtain a standard deviation from only one number?! Where are these raw data, Dr. Humphreys?"
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