Miracle of the Shroud II: The Second Coming

[Giordano]

The range of ages thrown out by the different labs indicates the larger the number of labs testing, the more statistically significant we can make our results.

Most statistical tests are based on deviations from the average. With just nine results from three labs, it becomes difficult to do any meaningful statistical analysis at all.

What we are testing is the reliabilty of the labs, not the cloth.

Obviously you are not reading any of the posts that have tried to explain the actual statistics. There is no point in continuing this aspect of the discussion with you.

 

[Dinwar]

Please explain.

You are presenting this as a sampling plan, when in reality it is quite obviously an attempt to eliminate any possibility of ever accepting any radiocarbon date.

Now that I've responded to multiple demands that I explain things to you, please find one or two requests for explanation that I've made.

Let's start simple: Please explain the marine bias as it applies to C14 dating.

 

[Vixen]

Ok, now I know you're taking the piss.

To clarify: you are saying that, if I want to be confident that a particular person is 170 cm in height, I must measure this person 200 times.

That's ridiculous. 2-3 measurements will do it.

I said nothing of the sort. You are being obtuse.

 

[Dinwar]

That implies to me they know it won't stand up to scrutiny.

This is because you are looking for excuses. A far more reasonable interpretation is that the Vatican has allowed it to be sampled and is satisfied with the results. There is NO requirement that hte Vatican comply with the demands of uninformed individuals who have no concept of the task they are proposing and who will not accept any answer anyway.

 

[Dinwar]

I said nothing of the sort. You are being obtuse.

No, that's EXACTLY what you are saying. To be sure of the date of one object we must measure it 200 times. This is precisely analogous to measuring the same person's height 200 times before accepting a height measurement.

 

[abaddon]

I'm not, but that's because I err on the side of denying destructive sampling of any artifact absent substantive reasons to do so. It has nothing to do with the shroud, it's just SOP. That said, I've given specific information that I would need to accept re-sampling as advisable, so I think I've avoided the guilt of irrational reluctance.

I agree. It's a medieval work of art worthy of preservation. However, Vixen is proposing destructive testing on a grand scale for no reason other that to satisfy idle curiosity despite the extant tests. That is irrational by definition.

 

[abaddon]

The range of ages thrown out by the different labs indicates the larger the number of labs testing, the more statistically significant we can make our results.

Most statistical tests are based on deviations from the average. With just nine results from three labs, it becomes difficult to do any meaningful statistical analysis at all.

What we are testing is the reliabilty of the labs, not the cloth.

Except it doesn't.

Tucson: 646 ± 31 years;
Oxford: 750 ± 30 years;
Zürich: 676 ± 24 years old;

Nothing in their results has even remotely error bars extending to 33AD.

 

[Vixen]

I am confused by your statistics. In my research, one often has to calculate in advance how many "n's" (replicates, samples, etc.) one would need in an experiment to get a certain statistically acceptable error. Of course the number of n's required depends on the distribution of the population, the reproducabilty of the experimental replicates, and on the confidence level that would be acceptable to the researcher (typically for a p=< 0.05). For most experiments, n is far less than 200! Often one can do an n=3 and get results that are statistically quite different from the null hypothesis by a p=<0.05 or much less (the smaller the p value the more confidence in the result not being due to random chance).

In your example, if you wished to calculate the average height of a Londoner, and you only measured 20, you could probably say that the height of a typical Londoner is within a range from 3 feet to 8 feet with a p value of =<0.05. But even 20 truly random samples would make a height of 1 foot very unlikely. The more people you measured the more accurately you could estimate the average height and the typical range of heights, but you wouldn't need to do 200 to simply rule out 1 foot as a typical height. You wouldn't even need to do 20.

This is generally true with all experimental data, and this type of statistical analysis is usually published with the data. In the case of the Nature paper, they indicated that the statistical error of their dates, even when considered lab by lab, was plus or minus less than 100 years with a p=<0.05. This did not require anywhere near the 200 samples you propose here. The possibility that these results could have been obtained by random chance from a 30 AD object is probably far less than one in a million (sorry, I haven't calculated the exact number yet).

Perhaps 200 more analyses might narrow the date a bit further, perhaps to +/- 10 years. But it would still come out as solidly Middle Ages.

Even the choice of "200" seems totally arbitrary. In science one first calculates the acceptable error, and then the number of n's required to obtain that error; 200 seems wildly off scale. And unnecessary: the published data already answers the central question, is the shroud 2000 years old, in a statistically very well documented way: no!

It's not really arbitrary; it's basic statistics if you want to go out and test your hypothesis and you want to persuade your peers your raw data is as pure as possible.

Obviously, you use common sense. The aim of your project will determine what parameters you decide to use. It comes with pitfalls so it is worth ensuring they are statistically sound and replicable.

I get that the scientists in the 1988 tests are adamant their results are foolproof. However, there is contention from others - whether rightly or wrongly - the test was flawed.

So, dear Vatican, please may we have further testing.

 

[Vixen]

I am calling troll now. it is quite clear you are taking a laugh here.

Anyway I am trying to picture that. You take the measuring band and you notice 1m70 for the person you measure (or whatever abominable imperial unit). Then you measure again that SAME person a second time. Find 1m70, then again, then again then again then maybe sometime you will get 1m69 because you are getting tired to do the same measurement..... Until you measure 200 time and show proudly your result at people which will then immediately edge toward the door looking at you very nervously.

Because measuring one person 200 time is a clear sign of insanity.

Straw man. That's your mock argument.

 

[abaddon]

That implies to me they know it won't stand up to scrutiny.

Who exactly knows "it" won't stand up to scrutiny?
WTH is "it"?

 

[Dinwar]

It's not really arbitrary

How did you arive at that number, then?

Obviously, you use common sense.

There's a laugh.

The aim of your project will determine what parameters you decide to use. It comes with pitfalls so it is worth ensuring they are statistically sound and replicable.

Well golly gee wiz! I bet NONE of the experts involved with the sampling ever thought of ANY of that!

I get that the scientists in the 1988 tests are adamant their results are foolproof.

False and flagrantly misrepresentative of the reality of the situation. The scientists were very clear as to the amount of error inherent in their methods. YOU have FAILED to provide substantive reasons to doubt them.

However, there is contention from others - whether rightly or wrongly - the test was flawed.

Irrational dismissal of the conclusions need not be taken seriously in science.

So, dear Vatican, please may we have further testing.

The ONLY reason you've given to justify destructive testing is "Irrational people don't accept the results we have." That is not a substantive reason to doubt the existing data and does not meet the criteria for allowing further destructive testing of an artifact.

 

[Vixen]

If you suggested this to an archeologist they would laugh. You don't need to because we know the constant rate of decay.

So explain how an Egyptologist at Manchester when sending mummy wrappings for carbon dating got a result showing the wrapping was 1,000 years younger than the mummy, when she knew as an expert, it had not been rewrapped.

It's all very well ppl saying one test is all you need, when there are ppl out there who have genuine reservations about the accuracy.

 

[Loss Leader]

Agenda? Is this a cunning form of logical fallacy? Appeal to hidden agenda.

What would that agenda be, catsmate?

Your agenda appears to be to make as much noise as possible. You are doing an admirable job.

 

[abaddon]

It's not really arbitrary; it's basic statistics if you want to go out and test your hypothesis and you want to persuade your peers your raw data is as pure as possible.

Yes. Your sample size is 1. Feel free to hold forth.

Obviously, you use common sense.

Appeal to common sense. Guess what? It ain't so common.

The aim of your project will determine what parameters you decide to use. It comes with pitfalls so it is worth ensuring they are statistically sound and replicable.

What "project"?

I get that the scientists in the 1988 tests are adamant their results are foolproof. However, there is contention from others - whether rightly or wrongly - the test was flawed.

And those same objections will be applied to any subsequent tests. So what's the point?

So, dear Vatican, please may we have further testing.

No point asking us, ask the Vatican.

 

[Vixen]

What if each of the three samples repeatedly gave much the same estimated date? As the Nature study did?

Much the same does not mean the same.

 

[Vixen]

Now I know you aren't a scientist.

That's a bit personal?

 

[Degeneve]

A minimum random sample of 200.

A "minimum random sample of 200" also means that you must cut parts the image from the cloth. Do you really think that the Vatican would allow it? Or any of the persons who claim the shroud is authentic?

 

[abaddon]

So explain how an Egyptologist at Manchester when sending mummy wrappings for carbon dating got a result showing the wrapping was 1,000 years younger than the mummy, when she knew as an expert, it had not been rewrapped.

It's all very well ppl saying one test is all you need, when there are ppl out there who have genuine reservations about the accuracy.

An unidentified "Egyptologist" sends unidentified sample to an unidentified lab and recieves unidentified results.

Well that's convincing.

 

[abaddon]

That's a bit personal?

Nope. Observation based on the evidence at hand. No more, no less.

 

[Dinwar]

So explain how an Egyptologist at Manchester when sending mummy wrappings for carbon dating got a result showing the wrapping was 1,000 years younger than the mummy, when she knew as an expert, it had not been rewrapped.

I would need proof that it happened.

I will ask again: What is the marine bias as it applies to C14 dating? You refuse to answer this basic question, and thereby increasingly support the conclusion that you don't understand C14 dating. And yes, this is potentially applicable to this question.

That's a bit personal?

You've accused entire institutions of gross incompetance and negligence. You don't get to complain when someone points out that your lack of knowledge of science is driving your demands, rather than any substantive criticism of the testing.

Much the same does not mean the same.

It's within the normal range of variability of these sorts of samples, and sufficient to establish the date as Medieval (and even what part of the Middle Ages). It can't tell you if it was Monday or Friday of the third week of June in 745 AD, but no test can do that. You are demanding an unreasonable and impossible level of accuracy.