Miracle of the Shroud IV - The Phantom Image

[John Jones]

I believe Hugh lives in the U.K., meaning that from late afternoon in the U.S. we can expect him to have retired for the evening.

True. It was unfair of me to hector him.

My apologies to Hugh Farey. My sciatica is acting up.

 

[Craig4]

Hugh,

- As frustrating as this debate feels to me (and, probably to you), I'm pretty sure that this is the way we're 'supposed' to do it... We're treating each other with respect, and we're honing in on basic disagreements. With a lot of luck, we might actually eliminate the divergence. With a little bit of luck, we'll identify exactly where we diverge -- which would be a good thing, a step in the right direction.

- Again, if I understand what you're saying, "context" is the key -- but in the sense that we simply don't have much context if the shroud is not authentic, and this lack of context on the inauthentic side increases the likelihood of no, or little, limestone on the cloth -- which decreases the likelihood that the cloth is inauthentic...
- That's a lot of twists and turns -- hopefully, I ended up in the right direction.

No Jabba, you are doing it wrong. Just give up on your little effective debate thing. Present evidence; that's how science works. You have to date the cloth. Nothing matters if you can't do that. No amount of blood, limestone or vanilin will make the slightest difference if you can't date the cloth. I know this is important to you but your beliefs about the CIQ are just nothing. They are made up without basis in fact.

You have to date the cloth. You have nothing without that. You might think you do but really, you're a member of the Flat Earth Society telling an airline pilot how to navigate. You can talk but you won't be adding value.

 

[Pixel42]

Crickets Chirping

ETA: I have not responded to your every sentence. That means nothing more than that I have not responded to them.

Hugh already explained his reasoning for saying that, though I can't be bothered to go back and find the post. He has personally investigated every claimed problem with the carbon dating and shown each to be groundless.

 

[zooterkin]

The number of churches in medieval Europe for which a very high quality, 4m long cloth might be made, and the chances of winning the UK lottery, about 1 in 14 million.

Actually, it's about 1 in 45 million now.

 

[Jabba]

Blood/What difference does it make?

Hugh,

- As frustrating as this debate feels to me (and, probably to you), I'm pretty sure that this is the way we're 'supposed' to do it... We're treating each other with respect, and we're honing in on basic disagreements. With a lot of luck, we might actually eliminate the divergence. With a little bit of luck, we'll identify exactly where we diverge -- which would be a good thing, a step in the right direction.

- Again, if I understand what you're saying, "context" is the key -- but in the sense that we simply don't have much context if the shroud is not authentic, and this lack of context on the inauthentic side increases the likelihood of no, or little, limestone on the cloth -- which decreases the likelihood that the cloth is inauthentic...
- That's a lot of twists and turns -- hopefully, I ended up in the right direction.

...That's quite clever, but no cigar, I think. I was speaking more of the context of the argument than the context of the Shroud. As it is, although you are correct that finding a cultural context for a medieval Shroud has proved difficult, it is becoming clearer by the day. That context certainly includes the likelihood both of blood and limestone, so I cannot agree that either of these are better evidence for authenticity than a medieval origin.

Hugh,

- I think that I'm just not explaining my case very well...
- Which, unfortunately, brings us back to Bayesian Statistics...

- What we're doing here is trying to determine the new probability of an old hypothesis when certain new info is added. In the limestone case, we learn that there is all sorts of limestone on the shroud. In my estimate, the likelihood of so much limestone being on the shroud -- given that the shroud is authentic -- is maybe 95% -- while the likelihood of so much limestone being on the shroud -- given that the shroud is inauthentic -- should be no more than, say, 50%. The reason for this relatively small likelihood -- given inauthenticity -- is our lack of knowledge about the shrouds origin under this "given." This forgery might have a lot of limestone on it -- but then again, it very well might not.

- So, the formula: P(A|x)=(L(x|A)*P(A)/((L(x|A)*P(A)+L(x|~A)*P(~A))
- And P(A|x)=.95*.1/((.95*.1)+(.5*.9), or .095/(.095+.0475), or .095/.1425, or .667.
- And, P(~A|x) would be .333. And consequently, this new information would slightly strengthen the probability of A -- or, authenticity. This new info favors authenticity more than it favors inauthenticity...

 

[MikeG]

Hugh,

- I think that I'm just not explaining my case very well...
- Which, unfortunately, brings us back to Bayesian Statistics...

- What we're doing here is trying to determine the new probability of an old hypothesis when certain new info is added. In the limestone case, we learn that there is all sorts of limestone on the shroud. In my estimate, the likelihood of so much limestone being on the shroud -- given that the shroud is authentic -- is maybe 95% -- while the likelihood of so much limestone being on the shroud -- given that the shroud is inauthentic -- should be no more than, say, 50%. The reason for this relatively small likelihood -- given inauthenticity -- is our lack of knowledge about the shrouds origin under this "given." This forgery might have a lot of limestone on it -- but then again, it very well might not.

- So, the formula: P(A|x)=(L(x|A)*P(A)/((L(x|A)*P(A)+L(x|~A)*P(~A))
- And P(A|x)=.95*.1/((.95*.1)+(.5*.9), or .095/(.095+.0475), or .095/.1425, or .667.
- And, P(~A|x) would be .333. And consequently, this new information would slightly strengthen the probability of A -- or, authenticity. This new info favors authenticity more than it favors inauthenticity...

Whatever you do with them consequently, if the basis for your calculations are made-up figures then the net result is bollocks. Don't computer people talk about "SISO" or somesuch?

 

[MRC_Hans]

Very true. However, the cloth from which the Shroud is made is of a very high quality, and extremely expensive. Whoever produced the image was either very rich or well trusted by his employer, not a clumsy hack with a sheet.

Funny, sindonists claim that the artist must have been better than da Vinci. .....

Anyhow, some historical context is important, here.

The Church was the richest and most powerful entity in Europe at that time, but it was far from united. There were bitterly warring fractions, even at exactly the time of the shroud two competing Popes. The Church people did not (usually) fight with swords, but with murder, assassinations, deceit, and intrigue. On the side, secular kings, nobles, warlords, etc were waging bloody local wars, while at the same time trying to be on reasonable terms with the Church. Human life and dignity, and the truth were all extremely negotiable values.

The fabric of the shroud was indeed very valuable at the time^*), but that's no guarantee whoever used it had actually paid for it. Or else, whoever donated it might have been promised an easy passage to Heaven in return.

The artist might not have been overly concerned with authenticy: Few people would have the slightest notion of how an authentic shroud might look, so the important part was that it be recognized as the shroud of JC, which meant that the image should look like the person on the crucifix next to it in the church.

The immidiate denouncement can very easily come from a competing fraction, which would, of course, hardly be happy if the competion owned the most sacred relic one could think of.

That, of course, means that we can hardly take d'Arcy as much more evidence than any disgruntled comepetitor, but it is, at least, the very first documented mention of the shroud's existence.

Hans

*) Albeit hardly comparable to the price of the ornate of even a Bishop.

 

[MRC_Hans]

Hugh,

- I think that I'm just not explaining my case very well...
- Which, unfortunately, brings us back to Bayesian Statistics...

Whcih, unfortunately, is irrelevant.

- What we're doing here is trying to determine the new probability of an old hypothesis when certain new info is added. In the limestone case, we learn that there is all sorts of limestone on the shroud. In my estimate, the likelihood of so much limestone being on the shroud -- given that the shroud is authentic -- is maybe 95% -- while the likelihood of so much limestone being on the shroud -- given that the shroud is inauthentic -- should be no more than, say, 50%. The reason for this relatively small likelihood -- given inauthenticity -- is our lack of knowledge about the shrouds origin under this "given." This forgery might have a lot of limestone on it -- but then again, it very well might not.

I estimate that the probability that a forgery has limetone on it to be 96%. Can you refute that figure?

Hans

 

[wea]

Hugh,...unfortunately..."Bayesian Statistics"(!)... blah blah...

A match! 699 more random guesses and let's see if you can do better than 1 over 10^{^83}
https://www.shroud.com/fanti3en.pdf


_____________________
"Most good ideas work"

 

[JayUtah]

...is maybe 95%
...should be no more than, say, 50%

No. You don't get to pluck numbers out of your orifice, apply a mathematical transformation to them, and pretend this gives you anything approaching science. Let's add Bayes and statistical inference to the list of things you don't know the first thing about.

This new info favors authenticity more than it favors inauthenticity.

No. It favors neither, as Hugh has explained and as your critics have explained to you for well over two weeks. You've flagrantly and deliberately avoided addressing their points. Do you have an explanation for this disrespect?

 

[JayUtah]

The fabric of the shroud was indeed very valuable at the time^*), but that's no guarantee whoever used it had actually paid for it.

I find it far easier to believe that a medieval artist obtained a rich cloth for his canvas than to believe a small first-century religious movement obtained one to wrap a corpse in. Too rich for art but not too rich for undertaking seems incongruous to me.

ETA: I meant to add that if Hugh seems to think it was improbable for a medieval artist to have obtained such a costly cloth, and that if Hugh doesn't believe the cloth is authentic, then what's his more probable origin hypothesis?

 

[Mojo]

No. You don't get to pluck numbers out of your orifice, apply a mathematical transformation to them, and pretend this gives you anything approaching science. Let's add Bayes and statistical inference to the list of things you don't know the first thing about.

See also:

http://www.internationalskeptics.com/forums/showthread.php?t=248163
http://www.internationalskeptics.com/forums/showthread.php?t=279595

 

[JayUtah]

Don't computer people talk about "SISO" or somesuch?

Garbage In, Garbage Out (or GIGO). I suspect what you mean by SISO wouldn't get past the profanity filter, but the concept is equivalent.

Bayesian statistical philosophy, among other things, allows you to reason using probabilistic degrees of belief. Which is to say, it provides a framework for reasoning with mathematical rigor about probabilistic values that are not derived from measured prevalence. But "rigor" here does not mean that assumptions are magically transformed into fact, as Jabba seems to want to make happen here.

So yes, you can properly reason among estimates of probability and arrive at sound inferences (as sound as an inferred probability can be, anyway) from them. But they are only as applicable as the initial estimates are valid. A more scientifically appropriate way of saying what you said in the part of your post I snipped out is that the technique here has value only if you agree with Jabba's wild guess estimate of p = 0.95 for limestone on an authentic shroud and p = 0.50 for limestone on a forged shroud.

Fringe theorists frequently turn to a misuse of Bayesian mathematics to lend the illusion of rigor to what are essentially questions begged in the form of made-up numbers.

 

[Mojo]

Garbage In, Garbage Out (or GIGO). I suspect what you mean by SISO wouldn't get past the profanity filter, but the concept is equivalent.

Something to do with "sidonist"?

 

[Jabba]

Blood/What difference does it make?

...
I estimate that the probability that a forgery has limetone on it to be 96%. Can you refute that figure?
Hans

Hans,
- See below.

...
- What we're doing here is trying to determine the new probability of an old hypothesis when certain new info is added. In the limestone case, we learn that there is all sorts of limestone on the shroud. In my estimate, the likelihood of so much limestone being on the shroud -- given that the shroud is authentic -- is maybe 95% -- while the likelihood of so much limestone being on the shroud -- given that the shroud is inauthentic -- should be no more than, say, 50%. The reason for this relatively small likelihood -- given inauthenticity -- is our lack of knowledge about the shrouds origin under this "given." This forgery might have a lot of limestone on it -- but then again, it very well might not...

...
- Again, if I understand what you're saying, "context" is the key -- but in the sense that we simply don't have much context if the shroud is not authentic, and this lack of context on the inauthentic side increases the likelihood of no, or little, limestone on the cloth -- which decreases the likelihood that the cloth is inauthentic...
- That's a lot of twists and turns -- hopefully, I ended up in the right direction.

 

[JayUtah]

Hans,
- See below.

How is that a refutation? You simply reasserted your wild guesses and referred to an illogical statement regarding context which you misunderstood from Hugh. I and others told you exactly how you had misinterpreted Hugh.

Try again.

 

[zooterkin]

Hans,
- See below.

That's a "No", then.

 

[hugh farey]

I have not responded to your every sentence. That means nothing more than that I have not responded to them.

Yes. Splendid reply. Me too.

We have some smart people here who have actually done ¹⁴C dating. They can explain it to us dummies.

Ah. Yes. Had you read my earlier post, even without responding to it, you would have seen that the expertise of the radiocarbon dating technicians is rarely questioned. What is questioned is the integrity of the sample. For example, at the recent St Louis Shroud conference, the Emeritus Professor of Mathematics and Computer Science at Bridgewater College, VA, delivered a paper directly correlating the dates given by the radiocarbon laboratories with the intensity of the ultra-violet fluorescence of the shroud at the sample sites. He said: “When you compare the laboratory carbon dates with the Z-Score resulting from a Principle Component Analysis (PCA) of the UV-Fluorescence data you get a coefficient of determination of 0.9986 which corresponds to a correlation coefficient of 99.93% a extraordinarily high value given that what it says is that the average carbon date is almost perfectly predicted by the UV-Fluorescence.” (‘Dating The Shroud Of Turin: Weighing All The Evidence’, at http://www.shroud.com/pdfs/stlschneiderpaper.pdf). This was music to the ears of the authenticists, as it seemed to indicate that contamination was almost certainly a factor in the upsetting of the established date. What's more, it was probably not, they thought, mere superficial, surface contamination, which would have been removed by the highly professional radiocarbon labs, but something more deep-seated, suggesting some truth in the 'interweaving' or invisible mending hypothesis. Whatever caused the variance in the UV fluorescence also caused the variation in the ages determined by the three radiocarbon laboratories. A number of other professors attended this presentation, and found no fault with it.

Would any of the radiocarbon experts who follow this forum like to help here? Are there any known possible contaminants which are difficult to remove from cloth, making radiocarbon dating not worthwhile? I believe some hydrocarbons are pretty intractable. Is this true?

So, the formula: P(A|x)=(L(x|A)*P(A)/((L(x|A)*P(A)+L(x|~A)*P(~A))
- And P(A|x)=.95*.1/((.95*.1)+(.5*.9), or .095/(.095+.0475), or .095/.1425, or .667.
- And, P(~A|x) would be .333.

Forgive me, Jabba, as I may have missed an earlier post in which you defined your terms, but could you say what P,A,x and L stand for?

 

[JayUtah]

...but could you say what P,A,x and L stand for?

They are from classical statistical modeling formulations. The notation P(A) is shorthand for "the probability of hypothesis A." The notation P(A|x) signifies "the probability of hypothesis A given observation x." The notation L(x|A) signifies "the likelihood of observation x having asserted hypothesis A."

ETA: A in his model is "The cloth is authentic." ~A is the negation: "The cloth is not authentic." x is the observation "There is aragonite limestone on the cloth."

It doesn't largely matter, since the values he's using in this model are simply plucked out of thin air, and quite obviously chosen to produce an answer he can style improperly as an objective probability that his circular reasoning has produced an accurate answer.

 

[zooterkin]

Yes. Splendid reply. Me too.

Ah. Yes. Had you read my earlier post, even without responding to it, you would have seen that the expertise of the radiocarbon dating technicians is rarely questioned. What is questioned is the integrity of the sample.

That may be the case in general, but not with the objections which Jabba has raised, and he is the only person currently championing authenticity in this thread. His objections have shown to be nonsense more than once, however they very much do question the expertise and/or motivation of the technicians:

- The following list is something I provided previously. Which specific claim would you like me to address first?

The Carbon Dating is suspect.
1. The emotionality in the 10 years of negotiation leading up to the test.
2. Significant protocols determined, but not followed.
3. The size and location of the sample.
4. Potential of repair, contamination and “new” linen.
5. Church (rather than scientists) selects sample.
6. Sample selected at the last moment, after two hours of “ecumenical” debate.
7. Final step in procedure seen by only 2 people, and not videotaped.
8. No test for chemical composition.
9. No archeologist involved.
10. STURP deliberately excluded.
11. Gove eventually excluded.
12. A clear age gradient within the sample.

Here’s a quote from “The Coming of the Quantum Christ” by John Klotz.[Professor Emanuela] Marinelli related to the Valencia Conference [in 2000] how competent scientists attacked the execution of the process and charged the labs with concealing the data necessary to determine adequately what they had done in their experiments. She cited a fifteen point critique of Philippe Bourcier de Carbon delivered at an international symposium in Rome in 1993: 14 (1) Absence of a formal report of the sampling; (2) Absence of a video archive on the final steps of the samples packaging; (3) In the official reports, contradictions about the cutting and the weight of the samples by people in charge of the sampling (4) Breaches of the protocols initially planned for the operation of dating; (5) Rejection of the usual procedure of double-blind test; (6) Refusal of the interdisciplinary documentation, which is usual in the procedures for radiocarbon dating; (7) Exclusion of acknowledged specialists in the Shroud, particularly American scientists who participated in previous works of STURP; (8) Communication to the laboratories, most unusual, of the dates of the control samples prior to testing; (9) Intercommunication of results among the three laboratories during the job; (10) Disclosure to the media of the first results before the delivering of the findings; (11) Refusal to publish raw results of the measurements (requested also with insistence in its official statement by the Scientific Committee which prepared the Symposium in Paris in 1989); (12) Non-explanation of the unique isolation of the confidence interval of the measures performed by the Oxford laboratory compared to those made by other laboratories; (13) Unacceptable value of 6.4 published in the journal Nature for the chi-squared statistical test on the results of the radiocarbon dosage on the Shroud; (14) Rejection of any cross-debate on the statistical measures performed; (15) Rejection, absolutely uncommon, of the publication of the statistical expertise of this operation, officially entrusted to professor Bray of “G. Colonnetti” Institute of Turin (requested also with insistence in its official statement by the Scientific Committee which prepared the Symposium in Paris in 1989).

Numerous respected scholars do not accept the carbon dating as final. For example, from http://shroudstory.com/:
Even the famous Atheist Richard Dawkins admits it is controversial.
Christopher Ramsey, the director of the Oxford Radiocarbon Laboratory, thinks more testing is needed. So do many other scientists and archeologists.
Philip Ball, the former physical science editor for Nature when the carbon dating results were published, recently wrote: “It’s fair to say that, despite the seemingly definitive tests in 1988, the status of the Shroud of Turin is murkier than ever.”