What is the Shroud of Turin?

Faith & Science Conversation
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Here’s my take on the Shroud, much of which I gathered for a good discussion between @Terry_Sampson and I.

  1. The claims of contamination and repairs as an explanation for the 14C dating doesn’t stack up. More than half the carbon would have needed to come from contamination, and that’s if all the contamination happened in the last 100 years. Analysis of possible repairs has also not stood the test of time.
  2. I find it illuminating that the 14C dates are consistent with the first appearances of the Shroud in history.
  3. The image doesn’t have the distortions one would expect from a cloth wrapped around a body (i.e. see Mask of Agamemnon).
  4. In order to address all of these issues, it is now proposed that a collimated beam of neutrons or some other collimated radiation pushed blood and various other things onto the Shroud, and at the same time somehow modified the Shroud so that it carbon dated to the same medieval time period where we have the first reports.

Overall, the authenticity of the Shroud has entered unfalsifiable territory. Any number of ideas will be put forward no matter what new data is brought forward. The science is there for people to consider, but I think the Shroud is better described as an article of belief.

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In fraud, yes.

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As one of an extremely small minority, I agree. Perhaps Moderators will pin or mark this thread for the benefit of others who may come along and ask the question.

For the record, a final word about John Calvin’s points against the Shroud’s authenticity.

One-paragraph synthesis

  • Calvin takes John 11, 19, and 20 plus 16th-century Jewish practice and builds a single, tight template: a body sheet that stops at the shoulders; a separate head-napkin; multiple image-cloth legends; and no Gospel mention of any image—therefore full-length “holy sudaries” must be late frauds and can’t be reconciled with John.

  • Hachlili and the Jericho data show that late Second-Temple Jewish burials wrapped bodies in shrouds (including the head), often with extra bands and possibly a face cloth, and that customs in this period were varied and short-lived, not identical to later rabbinic practice. That undercuts Calvin’s confidence that his 16th-century Jewish template can be read back unchanged into the 1st century.

  • Sindonologists leverage Hachlili’s broader picture to argue that a full-length shroud plus a separate face cloth is historically plausible. They interpret John 20 as describing exactly that: the head-cloth (Sudarium of Oviedo) rolled up separately and the remaining “linen cloths,” among them a large shroud (Turin), left on the bench. Whether one finds that convincing is another question—but on the narrow point you asked about, Calvin’s shoulders-only shroud rule is not really supported by the archaeological record Hachlili has given us.

Rachel Hachilili ??? JEWISH FUNERARY CUSTOMS DURING THE SECOND TEMPLE PERIOD, IN THE LIGHT OF THE EXCAVATIONS AT THE JERICHO NECROPOLIS1 RACHEL HACHLILI AND ANN KILLEBREW

  • Out of my league.
  • Guess you’ve never heard: “Robert de Clari, a crusader who described seeing a burial shroud in Constantinople in 1204, after which its fate became uncertain. The “de Charny” refers to Geoffrey de Charny, a later French knight who became the first documented owner of the Shroud of Turin in the 14th century. One theory links the two families through Othon de la Roche, a crusader who allegedly took the shroud to Athens after the fall of Constantinople, with the shroud later passing through his descendant Jeanne de Vergy and into the de Charny family through her marriage.”
  • Hanging your hat on Cicero Moraes claim and the medium that he used, eh? Make sure you get the fake blood stains on your shroud first.
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You could always ask an AI (or, if you don’t trust LLM AIs, ask a physicist):

What percentage of modern contamination would be required for carbon dating of a sample from the 1st Century AD to be misdated as coming from the late 14th or early 14th Century?

Short answer

About ∼62–68% modern carbon contamination (by carbon mass) would be needed to make a true 1st-century AD sample appear to date to the 14th century (1300s AD), depending on the exact years you pick and which half-life convention you use.

(Older contamination would require an even greater proportion.)

Your being ignorant of the physics behind why it is highly improbable for the Carbon Dating to be sufficiently wrong, due to contamination, for the Shroud to really be 1st-century AD, does not make it any less improbable.

Did Robert de Clari describe “seeing a burial shroud”? Peter Dembowski, in Sindon in the old french chronicle of Robert de Clari seems to think otherwise.

It is not even clear from this translation that de Clari was even describing what he himself saw, as opposed to hearsay as to the sights to be seen in Constantinople:

… about the other marvels that are there [in Constantinople], we shall leave off telling you; for no man on earth, however long he might live in the city, could number them or recount them to you, if any one should recount to you the hundredth part of the richness and the beauty and the splendor [lit. nobility] which was in the abbeys and the churches and in the palaces and in the city, it would seem that it were a lie and you would not believe. And among those other there was another church [lit. another of the churches] which was called My Lady Saint Mary of Blachernae , where there was the SYDOINES in which, [lit. where] Our Lord had been wrapped, which every Friday, raised itself upright, so that one could see the form of our Lord on it [lit. there], and no one, either Greek or French, ever knew what became of this SYNDOINES when the city was taken.

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  • You’re going to have to show me exactly which French and English words tell you that Dembrowski did not think Robert de Clari described “seeing a burial shroud”.

I’m having difficulty finding Dembrowski’s words that tell you that de Clari’s account was based entirely on hearsay and not on what he himself saw.

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Yes, on re-reading Dembowski, I see that I got turned around by his less-than-clear exposition, and that he did not in fact mean what I thought he did. For this, I apologise. I have stricken that comment.

That was my interpretation, not Dembrowski’s.

But it was my first point, that was my strongest. There simply is not way that contamination or repair could have affected the Carbon Dating sufficiently for the Shroud to be 1st Century, without it being blatantly obvious to simple inspection that the sample was anomalous. The Carbon Dating stands, and so the Shroud falls.

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First things first. You may or may not have been around the last time I said what I’m going to say, so I’ll repeat it now:

  1. Where my faith actually sits

Just so there’s no confusion:

  • My trust in the crucifixion, resurrection, and ascension of Jesus does not hang on a particular piece of linen.

  • If tomorrow you could prove, beyond all reasonable doubt, that the Shroud was woven in, say, AD 1350, I would not suddenly stop believing in Jesus. I’d say: “Okay, then it’s a devotional medieval artwork or something else. Interesting, but not decisive for my faith.”

So if part of the motivation in “The Carbon Dating stands, and so the Shroud falls” is an evangelistic hope that I’ll fall with it, I’m telling you plainly: that’s a category mistake. For me the Shroud is a historical / scientific puzzle, not the foundation of Christianity. Capisce?

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Yet you seemed strangely disinterested in the reliability of the only rigorously-conducted scientific testing of the shroud. I find that concerning, capisce?

I think you have an inflated view of my interest in your (or anybody else’s) religious views. If you’re not attempting to ram it down others’ throats, or making annoyingly-absurd claims in support of your views, then ‘it’s no skin off my nose’ :slight_smile:

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I don’t think you need an LLM or a physicist - a high school student studying maths should suffice.

Question 1. You have 100g material which is 2000 years old. What quantity of young material must be added in order for the average age of the combined old and young material to be 700 years if
a) the young material is 500 years old;
b) the young material is 30 years old.
Show your work.

Question 2. For 1(a) and 1(b) above, express the amount of young material added as a percentage of the total amount or young and old material, rounded to the nearest whole number. Show your work.

Question 3 (optional). If age determination is based on 45% of the mass of the 2000 year old material but 85% of the mass of the younger material,[1] how does this affect the answers to questions 1 and 2.

I think the answers are:
1a. 750g
1b. 194g
2a. 88%
2b. 66%
3. 344g, 77%; 102g, 50%
but I’m no longer a high school maths student[2].

If I’m right, the samples that were carbon dated would need to be either 23% linen and 77% soot (if the contamination was from the 1532 fire) or 50% linen and 50% soot (if the contamination was from the 1997 fire) or somewhere in between (if there was contamination from both fires) in order for the date produced to be due to contamination.

I suspect the people who took the samples and the lab techs who did the dating would have noticed that the supposed shroud material was more soot than linen. It would, to choose an appropriate simile, have been far more obvious than a coal pile in a ballroom.

Contamination simply cannot account for the C14 date, and anyone claiming it can either hasn’t done/can’t do the maths,[3] or is lying.

  1. The relative proportions of carbon in linen and soot ↩︎

  2. So I don’t need to show my work :smile: ↩︎

  3. I’ve encountered so many YECs who would flunk 5th grade maths that it’s almost an inference. It wouldn’t surprise me if the same is true for shroud advocates. ↩︎

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  • IMO your “concern” is your problem and you’re going to have to find a way to deal with your problem other than making it my problem. Personally, I’m not beyond adding you to my ignore list or flagging your concern for moderator attention.
  • I can guarantee you that my “strange disinterest in the reliability of the only rigorously-conducted scientific testing of the shroud” is the least of my “sins” that should concern you.
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From ChatGPT:

Roy, thanks for laying your numbers out so clearly. A couple of clarifications from the physics side, and then a point about what follows (and doesn’t follow) from your calculation.

1. Linear averaging vs. radiocarbon physics
What you did with your “high school maths” is to average calendar ages linearly. Radiocarbon dating doesn’t work that way. What actually mixes is C-14 activity, which decays exponentially; you then back-calculate a calendar age from the combined activity. If you redo your scenario using the proper exponential decay law (with a half-life of 5730 years), and ask:
– old material ≈ 2000 years;
– “young” material ≈ 500 years;
– mixed sample looks ≈ 700 years old;
you end up needing about 86% of the carbon in the sample to be from the younger material. If the “young” material is very young (say ~30 years old), you need roughly 63% of the carbon in the sample from that near-modern source to pull a 2000-year-old cloth up to a 700-year apparent age.

So your ballpark 88% and 66% aren’t exactly right, but they’re in the same neighborhood once you do the exponential correctly. In that sense, your intuition that you’d need a lot of younger material is sound.

2. But that doesn’t prove what you think it proves
Notice what your own numbers actually show:
– For a 1st-century cloth to look medieval, a large fraction of the carbon in the sample area would have to be younger.
– That’s exactly what the “reweave/repair” folks are claiming about that corner of the Shroud: not a light dusting of soot, but a heavily repaired edge made of younger threads interwoven with older ones.

In other words, your math (once done on activities) is consistent with their premise:

“If that corner really is a big hybrid of old and newer threads, the radiocarbon date of that corner will be too young.”

Where you and they disagree is not about the math, but about the textile history of that corner – whether that level of reweaving/repair actually exists and whether it could escape casual notice. That’s an empirical question, not a “coal pile in a ballroom” a priori certainty. The fact that professional textile people and chemists still disagree suggests it’s not as trivial as you’re making it.

Also, the main “contamination” hypotheses in the literature are not “soot from the 1532 and 1997 fires”; they’re:
– localized rewoven threads in the C-14 corner;
– and/or biogenic/organic coatings in that region.

So the picture “23% linen, 77% soot” is a bit of a strawman. Even if it’s your preferred view, it’s not what people like Rogers, Marino, etc., actually argued.

3. Contamination vs. honesty
You end with: “Contamination simply cannot account for the C14 date, and anyone claiming it can either hasn’t done/can’t do the maths, or is lying.”

With respect, that’s unfair. There are chemists and physicists (pro- and anti-authenticity) who have done the maths, understand the exponential, and still think the representativeness of that tiny corner is an open technical question. You may disagree with their textile or chemical arguments, but it’s a long jump from “I think their mechanism is implausible” to “they can’t do maths or they’re lying.”

For my part, I’m quite happy to say:
– The 1988 C-14 result is a serious piece of evidence that the tested corner is medieval;
– The proposed repair/contamination mechanisms would require a very large fraction of younger carbon in that region, and that’s a stiff hurdle;
– But the final word on whether that particular corner is fully representative of the whole cloth is a matter of textile and chemical evidence, not insult-level psychology.

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So a bit of C14th whole cloth is not statistically representative of the rest? By how many sigmata? And it wouldn’t be a matter of more C14 testing?

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‘Reweave/repair’ isn’t contamination, and wouldn’t be immediately obvious.

Biogenic/organic coatings is contamination and would be obvious, since it’d require 23% linen and 77% coating to get the measured C14 date.

So if you want to claim that the C14 dating was done on material that was taken from a mediaeval repair, that could work.

But I would ask why the people who extracted the samples for dating would have picked that part of the shroud to sample if they knew it had been repaired, and, if the sample-takers didn’t know that there was a repair to that section, or that it was somehow of different textile composition than the rest of the shroud - and they stated in their report that the samples were taken from a part of the shroud that had no signs of ever having been charred or repaired - how anyone else would know about such a repair or difference?

The ‘repair/reweave’ argument seems to be that the C14 date must be wrong, so there must have been something amiss with the sample, and since contamination would be visible the samples must be from a younger addition to the original material. That’s unconvincing. Anyone arguing that the wrong part of the shroud was tested should (i) have objected when the samples were taken, not after the results were known, and (ii) be requesting that the test be redone using a different part of the shroud.

Not that the C14 dating makes much difference. The shroud was already widely considered a forgery before the C14 dating was done. The C14 dating was just confirmation.

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Did you miss out a ‘t’ there?

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It also runs into the issue of the coincidence of the ‘repair’ introducing just the right amount of “young material” to make the test show the approximate date of the Shroud’s ‘rediscovery’ as its age. A little more or less repaired material, and the reported date would be too early for the Shroud to have been a recent creation at the time of its rediscovery, or too late for it to have even existed at that time.

Even if I thought that the dating was wrong, it would seem more likely that something like somebody substituting a fibre sample of the right age, or simply falsifying the rests, than this coincidence happening. Which puts us well into the territory of conspiracy theories.

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Let the record show that Terry Sampson did not start this thread and is not committed to keeping it “alive”.

The following is from ChatGPT:

Roy, thanks for the clarification — I actually agree with you on one important distinction you’re making:

  • “Reweave/repair” isn’t “contamination” in the narrow sense; it’s a structural heterogeneity in the sample area.

  • A biogenic/organic coating would be a form of contamination, and yes, to move a 1st-century sample into the 14th century by coating alone you’d need a very large mass fraction of younger carbon (your 23/77-type scenarios).

I’m not hanging my hat on “soot” explanations anyway, so I’m happy to leave those aside. The real question is the sample area itself, and here I think you’re skating past the actual debate.

1. The “reweave/repair” hypothesis is not just “must be wrong, therefore…”

You say:

“The ‘repair/reweave’ argument seems to be that the C14 date must be wrong, so there must have been something amiss with the sample… That’s unconvincing.”

But the actual sequence was the reverse:

  1. First: the 1988 Nature paper gives 1260–1390 AD for the corner sample and says the sample was from a region “away from patches or charred areas” with “no evidence of repair.” Astrophysics Data System+1

  2. Then: independent researchers started looking very closely at photographs and leftover threads from that same Raes/1988 corner. [Terry: see note far below.]

  3. Then:

    • Benford & Marino (2000ff.) proposed that the corner may involve “invisible reweaving” – old linen plus newer threads interwoven, specifically in that damage-prone edge. Shroud+1

    • Ray Rogers (STURP chemist, not a random blogger) did microchemical and pyrolysis-MS tests on threads from the C-14 area and from the main body of the cloth, and reported that the radiocarbon sample area had different chemical and physical properties: cotton, dye/mordant, retained vanillin, etc., compared to the image-bearing cloth. His conclusion was blunt:

      “The radiocarbon sample has completely different chemical properties than the main part of the Shroud. The worst possible sample for radiocarbon dating was taken.” Catholic Culture+2FishEaters+2

You may think Rogers and Benford/Marino are wrong — but it’s not true that they simply said, “The date must be wrong, therefore repair.” They looked at threads and chemistry first and only then said, “this corner doesn’t match the rest of the cloth.”

Textile expert Mechthild Flury-Lemberg, on the other side, strongly rejected the “invisible reweave” idea as technically implausible and claimed she saw no such repairs in 2002. Shroud+1

So at this point the issue is not reducible to:
“EITHER you’re bad at math OR you’re lying.”
It’s a live disagreement among chemists and textile specialists about whether that corner really is anomalous.

2. “If the sample-takers didn’t know, how could anyone else know?”

You ask:

“…if the sample-takers didn’t know that there was a repair to that section… how anyone else would know about such a repair or difference?”

Easy answer: because later investigators had different kinds of access:

  • They had microscopic thread samples from the Raes/C-14 area (not just a quick visual look at the surface) plus previous STURP samples.

  • They had time and mandate to do detailed chemical and spectroscopic work specifically on those threads (Rogers’ Thermochimica Acta paper is an example). FishEaters+1

  • They had high-resolution photographs and micrographs from the corner taken before/during sampling and before the 2002 restoration.

The Nature team in 1988 honestly reported what they believed: “no sign of repair or char.” That doesn’t magically make later microscopic and chemical evidence impossible. People are wrong about textile history all the time — especially when under pressure to cut as little cloth as possible and keep away from the image and the big Chambéry patches.

3. “They should have objected before… and now request a redo”

“Anyone arguing that the wrong part of the shroud was tested should (i) have objected when the samples were taken, not after the results were known, and (ii) be requesting that the test be redone using a different part of the shroud.”

(i) Before sampling:
There actually were voices in the late 1980s warning against over-interpreting a single-corner sample and raising the possibility of sample non-representativeness. Some of that made it into Nature itself in the form of letters and comments. Wikipedia+1
What no one had back then was Rogers’ later chemical data or the post-2000 reweave analyses. You can’t object to something you don’t yet know.

(ii) Requesting a redo:
You might be surprised how much agreement there is on that point. A number of people (on both sides of the authenticity question) now say:

  • The 1988 test used a single corner and the raw data show statistical heterogeneity among the subsamples. Wiley Online Library+2ResearchGate+2

  • Therefore a new dating, with multiple tiny samples from multiple locations, is the only way to settle representativeness.

But the Holy See has not authorized any further radiocarbon sampling since 1988. So it’s not that nobody is asking; it’s that the people who actually control the cloth have said “no more C-14 for now.” Wikipedia+1

On that, I’m with you: if we really want to resolve this, a properly designed multi-site test would be the way to go.

4. “It was already widely considered a forgery before C14”

Yes, there’s the famous 14th-century Bishop d’Arcis memorandum accusing it of being “cunningly painted,” and various modern skeptics who saw it as a forgery long before 1988. But there was never anything like unanimous “scientific” consensus that it was a fake:

  • The 1978 STURP team (hardly a pack of gullible mystics) concluded the image was not from paint, pigment, dye, or scorch in any ordinary sense, and they couldn’t reproduce it by known artistic techniques. PubMed Central+1

So pre-1988 you had:

  • Some historians and skeptics calling it a forgery,

  • Some scientists saying “this image is not a normal painting,”

  • And a long-running argument about its date and origin.

The C-14 result added a strong datapoint for a medieval date of that corner. It didn’t suddenly create the category “forgery,” and it didn’t make all contrary evidence evaporate.

For my part, I’m content with this:

  • The 1988 C-14 tests tell us something important about that corner taken as a bulk sample.

  • There are serious, peer-reviewed arguments that the corner may be anomalous (Rogers’ chemistry, Benford/Marino’s reweave data, Casabianca’s raw-data statistics), and serious counter-arguments. PubMed Central+3Shroud+3FishEaters+3

  • The statement “contamination/repair simply cannot account for the C-14 date” goes well beyond what the current evidence justifies.

=============================================================

  • * Terry’s Note:

Prompt to ChatGPT: “Why is “the corner” called “the Raes/1988 corner”?”

From ChatGPT: “It’s called the Raes/1988 corner because two different extractions, 15 years apart, were taken from essentially the same little corner of the Shroud:

  1. The “Raes” part (1973)

    • In 1973, Belgian textile expert Prof. Gilbert Raes was given a small, triangular sample from a corner of the Shroud to analyze.

    • That piece (now usually called the Raes sample) came from the lower left corner of the frontal image, along the side strip. It included:

      • Part of the main body of the cloth, and

      • Part of the narrow side strip sewn along the edge.

  2. The “1988” part (radiocarbon sample)

    • In 1988, when the radiocarbon dating was done, the Vatican and British Museum chose one single site to cut from for all three labs.

    • That site was just above and adjacent to the old Raes sample location, again in the same general corner area (same edge, near the junction with the side strip).

Because:

  • the 1973 Raes sample and the

  • the 1988 C-14 sample

both came from that same small region, Shroud researchers started referring to that zone as the “Raes/C-14 corner” or “Raes/1988 corner.”

Later work by Rogers, Brown, Heimburger, etc., all focus on threads from that specific corner, comparing:

  • Raes-sample threads (1973) and

  • radiocarbon-sample threads (1988),

which is why the double name has stuck.”

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It’s a fraud.

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That’s the same order: (i) wrong date, (ii) something amiss, (iii) propose younger addition. Not the reverse.

You should read ChatGPT’s output before posting it.

Since I’m not interested in conversing with a bot, I won’t respond to the rest.

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  • From Terry: Make me.

From ChatGPT: “Roy, let me clarify the timeline, because this part matters.

You’ve restated it as:

(i) wrong date → (ii) something must be amiss → (iii) propose younger addition.

But historically, that’s not how it unfolded for the people who later raised objections to the sampling corner. The actual chronology is:

1. BEFORE the 1988 dating — Raes already finds anomalies

In 1973, Gilbert Raes found:

  • Cotton fibers intermixed with the linen,

  • Different thread characteristics in part of that corner,

  • A seam joining a side strip whose history was unclear.

All of this was 15 years before the radiocarbon tests and 15 years before any “wrong date” existed.
These anomalies were real observations, not a reaction to 1988.

(This is why the location is now called the “Raes/1988 corner.”)

2. The 1988 sample was taken from that same anomalous region

The British Museum was specifically told to avoid patches, char, and seams — but the chosen spot happened to be precisely adjacent to the Raes sample, i.e., the very area already known to be unusual.

Whether that was wise or not is a separate question, but the fact remains:
1988 did not create concern about that corner — it reused a corner already under scrutiny since 1973.

3. AFTER 1988 — more anomalies discovered

Only after the Nature date was published did other researchers look closely at the leftover threads from the Raes sample and the radiocarbon cuttings, doing tests no one in 1988 had done:

  • Rogers (Thermochimica Acta, 2005) found gum, dye, mordants, cotton, and differing thermal behavior.

  • Benford & Marino (2000–2002) identified irregular weave structures and density variation indicating possible reweaving.

  • Brown & Schwalbe noted unusual splice-like features.

  • Casabianca (2019) showed statistical heterogeneity in the Oxford/Tucson/Zürich raw data.

Again — these findings came from examining the actual threads, not from reacting to an “undesired date.”

So the real sequence is:

(i) Observed anomalies in the corner (1973, Raes)

:down_arrow:

(ii) Radiocarbon sample taken from the same corner (1988)

:down_arrow:

(iii) Further chemical, microscopic, and statistical anomalies discovered (2000–2019)

:down_arrow:

(iv) Therefore: the representativeness of that corner is questionable

This is not “wrong date → invent excuse.”
It is “preexisting anomalies → more testing → more anomalies → therefore caution.”

If anything, your sequence is reversed relative to the historical record.

I did read ChatGPT’s response — the mistake here is not mine. The timeline is simply clearer than you think:

  • The corner was already known to be unusual long before 1988,

  • more unusual after 1988,

  • and that strengthens, not weakens, the argument about sampling location.”

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Obviously I can’t.

But I can ignore anything you post on the grounds that it’s probably ChatGPT-generated text that you haven’t checked.

Ciao.

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