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Author Topic:   Reliable Radiometric Dates as an Artifact of Assumptions
kbertsche
Member (Idle past 2121 days)
Posts: 1427
From: San Jose, CA, USA
Joined: 05-10-2007


Message 21 of 30 (590108)
11-06-2010 12:51 AM
Reply to: Message 13 by Itinerant Lurker
11-03-2010 11:06 PM


Re: Thanks
quote:
Sweet. I think I've gotten the issues down concisely as they're going to get over there:
Ryan R:
I've already told you why I'm skeptical of outliers and such, and you were trying to get me that data. If you do, I'll be able to show you how those outliers are treated and what that implies and, if you provide me with data from multiple tests used on the same sample and a description of how the instruments are calibrated, I'll be able to show you whether or not there are relationships in the data (correlations), or if they're coincidence (based on insufficiency of data to establish relationship or frequency of falling outside the appropriate standard deviations on either side within the accepted confidence interval), or if they are actually codependents (as in calibrated off of one another or according to similar assumptions).
I'm going to try and turn this into a sensible question to email off to Beta Analytic, are there any other suggestions anyone has on where to look for the above information? Thanks.
Lurker
Calibration is simple in principle, but gets somewhat tricky and detailed in practice. To really understand it requires some practical knowledge of analytical instrumentation and measurements (certainly more than your critics seem to have).
In principle, one frequently measures a "blank" with essentially no radiocarbon to correct for drift of the instrument's "zero" level, and a "standard" of known (roughly modern) activity to correct for instrument gain. With these two calibration standards, one can correct for both the zero offset and the gain of the instrument. But the instrument will drift over a time scale of hours, so these samples need to be measured on a similar time scale, and the instrument drift needs to be corrected with a linear or a more complex fit.
I wrote up a critique of ICR's RATE study a couple of years ago. This is concise and dense, but may have some useful information. You can find it at a number of places:
RATE's Radiocarbon - Intrinsic or Contamination?
Page not found - Reasons to Believe
RATE’s Radiocarbon: Intrinsic or Contamination?

This message is a reply to:
 Message 13 by Itinerant Lurker, posted 11-03-2010 11:06 PM Itinerant Lurker has not replied

  
kbertsche
Member (Idle past 2121 days)
Posts: 1427
From: San Jose, CA, USA
Joined: 05-10-2007


Message 26 of 30 (590147)
11-06-2010 9:40 AM
Reply to: Message 22 by Itinerant Lurker
11-06-2010 3:05 AM


Re: Parchance
quote:
One is ". . .a professional researcher dealing with primary and secondary qualitative and quantiative research." and essentially makes the claim that scientists simply aren't as qualified as analysts to determine whether radiometric dating data show actual relationships or just coincidences.
As nwr says, this guy sounds like he understands statistics at some level, but not necessarily their particular application to scientific instruments or physics experiments. Radiocarbon AMS started in nuclear physics laboratories, using the same sort of statistical techniques that are used in nuclear physics. These techniques should be perfectly adequate for routine radiocarbon dating. More sophisticated techniques have been applied to generation of calibration curves, especially to "wiggle matching" to match up data from trees, lake varves, speleothems, etc (as in the calibration curve you presented).
You might want to show your critics some of the particular statistical techniques that are used in radiocarbon dating; I think they'd be satisfied with the rigor of the analysis. Here are some links:
Various papers in Radiocarbon 40(1)
Various papers in Radiocarbon 51(4)
Philosophy of science paper by Steel
Edited by kbertsche, : No reason given.

This message is a reply to:
 Message 22 by Itinerant Lurker, posted 11-06-2010 3:05 AM Itinerant Lurker has not replied

Replies to this message:
 Message 27 by NoNukes, posted 11-06-2010 11:14 AM kbertsche has seen this message but not replied

  
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