Miracle of the Shroud / Blood on the shroud

[pgwenthold]

All this talk of bias begs the question: bias towatd what?

Why would the labs that did the measurements be biased toward a later date?

It's not for fame. They would be equally famous regardless of whether they found an early or late date. All three labs are staffed by anti-christians, hell-bent on disproving the authenticity?


Seriously, if one is go around throwing accusations of bias, it might be helpful to explain they should even gave a bias in the first place.

Is there any reason to think all the labs were out to disprove the shroud? If not, why shoukd ee yhink they were biased toward one date or the other?

 

[pakeha]

^
Keep in mind we're talking about a mysterious, unsung movement which involves the Church, Oxford Uni, Los Alamos, the British Museum, Tucson, the leading textile experts in the world, the Turin bishipric and rather likely the cotton glove manufacturers of the world, to boot.

The pathetic absurdity of the Shroudies' claims is getting more obvious by the day.

 

[wollery]

Sorry, it just occurred to me that it might be useful to explain the point of, and need for, double blinding in scientific tests.

The most obvious example of the use of double blind testing is in drug trials. In order for a drug trial to have any merit at all it must be rigorously double blinded.

The reason for this is simple, a large part of the data in drug trials is the reporting of symptom levels by patients themselves. There's no reliable measure for pain other than to ask the patient to rate the pain they are feeling. Similarly, emotional states and general feelings of well-being are totally subjective. For this reason it is vitally important that the patient doesn't know if they are receiving the drug or a placebo. It should be obvious why - if a patient knows that they are getting a placebo they are unlikely to report feeling better even if their condition does actually improve, whereas if they know for certain that they are getting the drug then they will almost certainly report improvements, even if there are none in actuality.

But that's just single blinding. In double blinding the doctor has no idea whether the patient they are treating is getting the drug or the placebo. And there is a very good reason for this - if the doctor knows then s/he may treat the patient differently, more positively if they are getting the drug and more negatively if they are getting the placebo, which will affect the patient's reactions and feelings, and alter their reporting of symptoms.

So because the patients and doctors have no idea who is on the drug and who is on the placebo there is just no way that that knowledge can impinge on the results of the trial. If a properly double blinded trial produces results significantly above those of the placebo the drug must be having a real effect. If, on the other hand it has no better effect than the placebo the it's safe to say that it has no tangible effect. In a non-blinded trial you would expect the drug to do far better than the placebo, so such a result doesn't really tell you anything useful about the drug.

In short double blinding guards against unintentional changes to subjective measurements.

So why isn't blinding needed in astronomy or radioisotope dating? Because these things don't use subjective measurements. You don't ask a soil sample how much pain it's experiencing. You don't enquire after the emotional state of a protostellar object. You take hard, verifiable, objective measurements of their physical or chemical parameters. There is simply no subjectivity to blind against, which means there's absolutely no need for blinding of any sort.

 

[Aepervius]

You don't ask a soil sample how much pain it's experiencing.

Tell that to the guy which was mesuring "pain" into plants .


Just kidding good post.

 

[wardenclyffe]

- I think that my position has changed more than it appears.


- Yes.


- Yes.


- Yes.


- I think that there was something done, somewhere back in time, to that particular area of the Shroud that was not done to the greater Shroud.

- Not quite. While I do think that there was something "different" done to that area of the Shroud, I'm much less convinced (than I had been previously) that an actual "patch" of some size was involved.

- I think that the only thing you're missing is my alleged evidence that something different had been done to that area of the Shroud. I alluded to that evidence previously, but didn't give any specific supportive claims except for a few paragraphs from the Rogers' paper. It's now up to me to provide the other specific claims I was alluding to. - Unfortunately, I have to admit now that in reviewing one of the other sources to which I alluded, I discovered that the Raes source, was (apparently) not my only source that only referred to the Raes sample...--- Jabba

I can wait. Waiting has not harmed me so far, only aged me.

Ward

 

[catsmate]

I was going to follow-up my original post dealing with provenance and chain of custody with another asking how the lab might have handled the samples, specifically with regard to whether the people doing the testing could have deduced or known which sample was the actual shroud material and which samples were the controls.

Dinwar just showed us how awesome he is by answering my question before I even posted it!

I seems like everyone in the labs probably knew that they were dealing with the shroud dating, and probably figured out which sample was the shroud within moments of the containers being opened. But that did not bias their results. After all, they had nothing to gain by giving a false date to the Vatican and stood to lose their reputation had they done such a thing.

Using three labs was good, because all three were in agreement as to the dates of the three samples. It would have required active collusion on the part of the labs to have given falsified results.

As has been mentioned, and is discussed in the original Nature paper that Jabba doesn't seem to have bothered to read, the shroud samples weren't blinded when provided to the testing laboratories along with the three control samples. The whole idea of blinding the process was one introduced by STURP, when the lab representatives met with the Vatican they pointed out the problems with this idea; the material would have to be shredded, rendering the decontamination process more complicated and probably less effective. Hence it was dropped. This was accepted by Gonella.
However two of the labs, Oxford and Zurich, did blind their samples; after combustion the four samples were relabeled and the staff performing the dating did not know which was from the shroud.

I think Jabba may be under the mistaken impression that the carbon dating was supposed to be done blind, and therefore the fact that the samples were distinguishable from the controls was a shortcoming of the carbon dating process.

STURP proposed it, the scientists doing the testing rejected it for the reasons give.

After Dinwar's and wollery's posts, it's clear that the controls were a check on the accuracy of the carbon dating process itself - as the controls were correctly dated, we can be confident that the sample from the shroud was correctly dated.

Exactly.

As two of the labs did do some of the calculations blind (as described by that last sentence of the Nature quote that Jabba suggests he doesn't understand), any hypothesised collusion between the three laboratories can be falsified, too.

Exactly.

 

[pakeha]

Here are Professor Christopher Ramsey's comments on the dating

There have been suggestions that the radiocarbon process got it wrong – but this is unlikely, according to Professor Christopher Ramsey of the Oxford Radiocarbon Accelerator Unit, one of three labs which carried out the research. "We're pretty confident in the radiocarbon dates," he told me. "There are various hypotheses as to why the dates might not be correct, but none of them stack up.

"One is that the samples were contaminated. But that doesn't work, because to make an 2,000-year-old object appear just 800 years old, about half the material would have to be contaminant, and that's if it was all modern. If it was older, it would have to be even more. Various tests done at the time of the original measurements also suggested that the material was fairly pure. It's also been hypothesised that the patch we tested was a modern repair, but most of us agree that's implausible, because the weave is very unusual and matches the rest of the shroud perfectly. Then there are more complicated notions, like contamination with carbon monoxide, but tests have shown that carbon monoxide doesn't react with the fabric under the circumstances that you might expect."

Regarding the ENEA findings, he is similarly sceptical."There are several possibilities, and it could just be a chance effect due to a number of different phenomena," he say. "But in archaeological science, being able to reproduce something doesn't imply that that's the technique used; it may simply show that you've got a new technique you want to try out." He adds that the confidence in the medieval result is such that, were it not suggested to be a relic, there would be no more discussion over its age."

http://blogs.telegraph.co.uk/news/tomchiversscience/100125247/the-turin-shroud-is-fake-get-over-it/


I'm still not clear what the Shroudies' objections are at this point.
Patching is out, contamination is out so what is left?

 

[catsmate]

Here are Professor Christopher Ramsey's comments on the dating


http://blogs.telegraph.co.uk/news/tomchiversscience/100125247/the-turin-shroud-is-fake-get-over-it/


I'm still not clear what the Shroudies' objections are at this point.
Patching is out, contamination is out so what is left?

1. Giant conspiracy between the Vatican the labs. For some reason............
2. God magic.

 

[tsig]

All this talk of bias begs the question: bias towatd what?

Why would the labs that did the measurements be biased toward a later date?

It's not for fame. They would be equally famous regardless of whether they found an early or late date. All three labs are staffed by anti-christians, hell-bent on disproving the authenticity?


Seriously, if one is go around throwing accusations of bias, it might be helpful to explain they should even gave a bias in the first place.

Is there any reason to think all the labs were out to disprove the shroud? If not, why shoukd ee yhink they were biased toward one date or the other?

Satan, we all know he works incessantly to block the truth of Jesus.

 

[tsig]

Here are Professor Christopher Ramsey's comments on the dating


http://blogs.telegraph.co.uk/news/tomchiversscience/100125247/the-turin-shroud-is-fake-get-over-it/


I'm still not clear what the Shroudies' objections are at this point.
Patching is out, contamination is out so what is left?

If you close your eyes and believe real hard you can make it so.

IOW faith

 

[pakeha]

Evil scientists, the Vatican, the devil...
Yeah.
That works for me.

ETA
Faith, not so much.

 

[tsig]

Evil scientists, the Vatican, the devil...
Yeah.
That works for me.

(did the devil steal your other avatar? This one looks like captain's bars)

 

[Garrette]

Here are Professor Christopher Ramsey's comments on the dating


http://blogs.telegraph.co.uk/news/tomchiversscience/100125247/the-turin-shroud-is-fake-get-over-it/


I'm still not clear what the Shroudies' objections are at this point.
Patching is out, contamination is out so what is left?

Same as always: lying and denial.

 

[Pixel42]

The whole idea of blinding the process was one introduced by STURP, when the lab representatives met with the Vatican they pointed out the problems with this idea; the material would have to be shredded, rendering the decontamination process more complicated and probably less effective. Hence it was dropped. This was accepted by Gonella.
However two of the labs, Oxford and Zurich, did blind their samples; after combustion the four samples were relabeled and the staff performing the dating did not know which was from the shroud.

I must admit I had assumed all the testing was blinded (the fact that the weave of the Shroud would give it away hadn't occured to me) so I'm glad to see that as much blinding as was possible was still done. Having said that, the point that such blinding was not actually necessary to ensure accurate dating, regardless of any bias the scientists might have had, is taken.

 

[Belz...]

Satan, we all know he works incessantly to block the truth of Jesus.

No, I really don't have that time to waste.

 

[catsmate]

I must admit I had assumed all the testing was blinded (the fact that the weave of the Shroud would give it away hadn't occured to me) so I'm glad to see that as much blinding as was possible was still done. Having said that, the point that such blinding was not actually necessary to ensure accurate dating, regardless of any bias the scientists might have had, is taken.

Yeah, once the AMS radiocarbon dating experts got involved in the process they pointed out that because of the weave the sample would have to be shredded to be indistinguishable from the other samples. Which would have made the cleaning/decontamination preparation far more difficult.

 

[pakeha]

(did the devil steal your other avatar? This one looks like captain's bars)

http://www.nj.com/news/index.ssf/2013/03/red_equality_symbol_gaining_tr.html

I was considering, because it's Holy Week, and as I may have mentioned earlier, there ARE no atheists in Spain during Holy Week, using a little clip of a most ah unique procession, that of Los Novios de la Muerte strutting their stuff.

Just so no one has to miss on this
1st part
El Disembarque
http://www.youtube.com/watch?v=g_UeYbLt3RM

2nd El Traslado
http://www.youtube.com/watch?v=_GWsLtTFbpw

La Procesion
http://www.youtube.com/watch?v=nl4GPUPSBiU&feature=endscreen

But then I thought, no.
Gay marriage.
Definitely gay marriage.

 

[tsig]

http://www.nj.com/news/index.ssf/2013/03/red_equality_symbol_gaining_tr.html

I was considering, because it's Holy Week, and as I may have mentioned earlier, there ARE no atheists in Spain during Holy Week, using a little clip of a most ah unique procession, that of Los Novios de la Muerte strutting their stuff.

Just so no one has to miss on this
1st part
El Disembarque
http://www.youtube.com/watch?v=g_UeYbLt3RM

2nd El Traslado
http://www.youtube.com/watch?v=_GWsLtTFbpw

La Procesion
http://www.youtube.com/watch?v=nl4GPUPSBiU&feature=endscreen

But then I thought, no.
Gay marriage.
Definitely gay marriage.

Thanks....I think.

 

[Dinwar]

When I was working with an atomic absorption spectrometer (running Windows 3.1--we couldn't get spare parts for the computer anymore!), we had a pretty standard protocol: run a series of standards of known concentrations of the element in question, then run a number of samples (10 or so where possible), then run more standards. That's why I've always said that we could get down to 10 ppm for some elements--our actual results were something like 3.471 ppm, but given the range of error in the standards we couldn't actually say our results were that good.

Then I'd throw a standard in as a sample, just to double-check (clearly labeled and noted in the lab book; it wasn't a required part of the protocol, but when you see the same water giving you different concentrations you get rather concerned, so I did it to test the machine). Those weren't blinded at all, but as wollery said, they didn't need to be--I knew the what the standards were supposed to read, and they were just to check the machine (power surges were the cause, by the way--I started doing my sampling when no one else was in the building and that particular problem went away).

As wollery said, blinding is only useful when there's some aspect of subjectivity to the process. If there's not, blinding is merely a very good way to render your samples worthless. What I mean is, blinding isn't going to make your data any better, and you're adding another step, which means you're adding another place where people can misread handwriting, the ink can smear, etc. While blinding certainly can be useful, there ARE risks, which must be weighed against the gains. It's expensive to have a field crew go out and re-sample a groundwater well or soil pile. It's vastly more expensive--if not impossible--to re-take a sample from a priceless artifact (and I want to say again that the shroud is still a priceless artifact, even though it's a clear fraud).

Thanks for the explanation about the reason blinding wasn't done, catsmate1. While I don't think blinding would be necessary, it's good to know it was considered, and the reasons for rejection. I can well imagine that meeting, too...Clients are bad enough when you tell them they're being idiots. Third parties are even worse, by FAR!

 

[Elind]

This shroud rubbish should be put in the UFO section.