The Shroud in colour

The Shroud in colour

A piece of linen cloth, 4.34 m long and 1.09 m wide, kept in the cathedral at Turin (Italy), has been claimed as the burial shroud of the Jewish prophet Jesus of Nazareth, in whose name the Christian religion was founded. It is thus venerated as a ‘relic’: an object with special properties of sanctity derived from its (alleged) connection with someone considered especially holy. In the case of an object supposedly associated with the death and resurrection of a person claimed by adherents of the Christian belief system to be a third part of their god, this makes it about as holy as anything could possibly be.

It has been claimed that the Shroud is “the most intensely studied artefact in human history”, which may be a bit of an exaggeration, but which is probably not far from the truth. The modern interest in it, which began this intense scrutiny of evidence for its authenticity, began in 1898, when Secondo Pia, a Turinese lawyer and keen photographer obtained permission to photograph the cloth during its exposition that year. As he developed his plate, he became aware of a curious phenomenon: the indistinct, yellowish markings on the cloth now appeared more definite and, curiously, the negative plate more closely resembled a positive portrait photograph than a negative. To Pia, this was clear proof that the cloth could not have been a forgery, for what forger could have anticipated the invention of photography and created a negative? Pia’s discovery seemed to confirm a miraculous origin for the image on the cloth and there the matter rested for many years, the credulous and faithful seeing it as a genuine relic of the resurrection of Jesus, the sceptical regarding it as a skilful medieval forgery.

Following the publication of a couple of posts at the Shroud of Turin Blog, accusing us of doing Bad Archaeology, I’ve largely rewritten this page. It is always useful to receive the sort of criticism found on the blog: it is written by people who know the subject in far greater detail than I will ever do and it challenges ideas that I have derived from other sources. It forces me to look more critically at the evidence.

Historical data

The first time we hear of the Turin Shroud is in 1389×90, when Pierre d’Arcis (or d’Arcy, Bishop Pierre II of Troyes 1377-1395) wrote a letter to Pope Clement VII (1342-1394, elected Pope at Avignon in 1378, in opposition to Pope Urban VI). He objected to an exposition of the shroud in the collegiate church at Lirey on the grounds that it was being done by a landowner, who “falsely and deceitfully, being consumed with the passion of avarice, and not from any motive of devotion but only of gain, procured for his church a certain cloth cunningly painted, upon which by a clever sleight of hand was depicted the twofold image of one man, that is to say, the back and the front, he falsely declaring and pretending that this was the actual shroud in which our Saviour Jesus Christ was enfolded in the tomb and upon which the whole likeness of the Saviour had remained thus impressed together with the wounds which He bore”. He pointed out that in view of the lack any earlier mention of a shroud bearing an image of Jesus, “it was quite unlikely that the Holy Evangelists would have omitted to record an imprint on Christ’s burial linens, or that the fact should have remained hidden until the present time”.

Moreover, he complained that this was not the first such exposition at Lirey, one having been made some years earlier, when Geoffroi I de Charney had deposited it in the collegiate church built in 1353. This happened around 34 years before Pierre II wrote his letter, so around 1355×6 (Geoffroi I de Charney died in the latter year). His letter claims that his predecessor as Bishop, Henri de Poitiers (Bishop of Troyes 1353-1370), had made enquiries about the origin of the cloth and found that “after diligent inquiry and examination, he discovered how the said cloth had been cunningly painted, the truth being attested by the artist who had painted it, to wit, that it was a work of human skill and not miraculously wrought or bestowed”. This early exposition is attested archaeologically in the form of a pilgrim badge found in the River Seine at Paris, depicting the Shroud accompanied by the arms of Geoffroi I de Charney and of Jeanne de Vergy, his second wife.

In the meantime, Geoffroi II de Charney had written directly to the Pope in Avignon (whose uncle had married Geoffroi’s stepmother Jeanne) asking for permission to show the family’s shroud. Presumably, this was because of Bishop Henri de Poitiers’s negative conclusions about its authenticity. Clement VII issued four Bulls (dated 6 January 1390) permitting the exposition of the Shroud, with the caveat that it was not to passed off as the “True Shroud”, suggesting that he knew of the former Bishop’s inquiries. This took place before Bishop Pierre II’s letter had even been sent, rather undermining his authority. Even so, after receiving Bishop Pierre II’s letter, the Pope responded to Geoffroi II confirming permission to exhibit, to Bishop Pierre commanding him to keep “perpetual silence” about his discoveries under threat of excommunication and to other ecclesiastics in the diocese asking them to ensure that his instructions were followed.

The subsequent history of the Lirey Shroud is well documented. It was entrusted in 1418 to Humbert de Villersexel (1385-1437, Count de la Roche), who had married Marguerite de Charnay in that year. It was initially kept in his Château at Montfort and was later taken to Saint-Hippolyte; although the canons of Lirey attempted to retrieve the Shroud after Humbert’s death, Marguerite would not give it up and travelled around France with it. In 1452, Marguerite de Charnay presented it to Anne de Lusignan (1418-1462), wife of Louis (or Ludovico, Duke of Savoy 1440-1465), in exchange for the Château of Varambon.

The Shroud was kept in the Savoie family’s Château at Chambéry for a while until a decision was made in 1471 to display it in cities across Europe.  It was damaged by a fire in 1532, when the silver reliquary in which it was stored began to melt, a droplet of silver burning a hole through the cloth. The holes were subsequently repaired with patches that were removed in 2002. It remained the property of the Duchy of Savoy until it was bequeathed to the See of St Peter in 1983.

The Lirey cloth was one of three in France alone that were claimed to be the Shroud of Jesus. An example in Compiègne is first attested in 877, while another at Cadouin was obtained in Antioch in 1098. Neither of these shrouds bore images and the Cadouin example was shown in 1935 to be of eleventh-century date. Forty other shrouds are attested in Europe alone. Clearly, the Turin Shroud is just one of many claimants.

Scientific studies

Two scientific studies of the cloth were made in the 1970s, one in 1973 and one in 1978. The first study remains less well known than the second, as its findings were published only in Italian. It was the outcome of a commission set up in 1969 by Cardinal Pellegrino, specifically charged to examine the cloth’s condition, take new photographs and to make recommendations on its conservation. The results were announced by the Centro Internazionale di Sindonologia (International Centre of Sindonology) in Turin.

The best known result of these tests was the report on pollen by Max Frei, who claimed to have identified among 49 different species of pollen spores, 13 that were “very characteristic of or exclusive to the Negev and Dead Sea area” and 20 others suggestive of Anatolia (Edessa and Istanbul, specifically). However, there were problems. Olive pollen ought to dominate a cloth from Palestine, yet none was identified. Max Frei’s credibility suffered a serious blow when, as a self-proclaimed handwriting expert, he announced that the “Hitler diaries” were genuine and when it was revealed that a fellow Swiss police forensic scientist revealed that Frei had been found guilty and censured by his superiors on several occasions for the over-enthusiastic interpretation of samples.

The weave of the Turin Shroud

The weave of the Turin Shroud

On the other hand, Gilbert Raes’s analysis of the textile concluded that its hand-spun twill (three-to-one herringbone) weave was common at many different periods but not in Palestine or Egypt in the first century CE, where tabby (plain) weave was usual, as seen on Egyptian mummy cloths and the wrappings of some of the Dead Sea scrolls. A few cotton fibres of the species Gossypum herbaceum were also present: cotton was first imported into Europe during the twelfth century CE but was used in the Near East during the time of Jesus, so their presence was inconclusive. However, as their presence was probably due to the weaving being done on a loom previously used for weaving cotton cloth, it is unlikely to have occurred in an orthodox Jewish context, where separate looms would be required. Thread samples from both ‘body’ and ‘blood’ parts of the image were removed and examined for traces of pigment, which proved negative in both cases. Tests for blood residue were also negative. Microscopic examination showed that the image consisted of fine yellow to red granules on the surface of the fibres.

One suggestion, made by Silvio Curto, a collector of Egyptian cloth, was that the Turin Shroud might be authentic or might be no earlier than the tenth century CE. This is typical of the results of the 1973 tests: they were completely inconclusive. What they appeared to show was that the cloth was unlikely to have been made in an orthodox Jewish weaving shed, had spent time in different locations from the Middle East to northern Europe and was of a weave that was characteristic of medieval European cloth. The tests could not show how the image was formed.

STURP

The second 1970s project is better known, thanks to a concerted campaign by many members of the team to publicise what they saw as clear proof of the shroud’s authenticity. Known as STURP (the Shroud of TUrin Research Project Inc.), the membership of the project varied and it is clear that there were considerable tensions within the group. Members were forced to sign an oath of secrecy, preventing them from publishing individual test results before a final report was due to be published in 1980. By that time, there was no sign of a report and individual team members had published their results elsewhere. And those results were controversial: team members disagreed with each other over the significance and meaning of what they had found in a war of words that was conducted in public. Indeed, it was never able to make a formal, conclusive report, perhaps in part because it was caught up in political and religious intrigues.

An incomplete list of those involved includes: Joseph S Accetta (Lockheed Corporation), Al Adler (Western Connecticut State University), Steven Baumgart (US Air Force Weapons Laboratories), Ernest H Brooks II (Brooks Institute of Photography), Robert Bucklin (Medical Examiner’s Office, Harris County, Texas),  Donald Devan (Oceanographic Services Inc.), Rudolph J Dichtl (University of Colorado), Rev. Robert Dinegar (Los Alamos National Scientific Laboratories), Thomas F D’Muhala (Nuclear Technology Corporation), Tom Dolle (Christ Brotherhood), Jim Drusik (Los Angeles County Museum), Mark Evans (Brooks Institute of Photography), Joseph Gambescia (St Agnes Medical Center), John D German (US Air Force Weapons Laboratories), Roger & Marty Gilbert (Oriel Corporation), Gary Habermas (Liberty College), Thomas Haverty (Rocky Mountain Thermograph), John Heller (New England Institute), John P Jackson (US Air Force Academy), Donald & Joan Janney (Los Alamos National Scientific Laboratories), Eric J Jumper (US Air Force Academy), J Ronald London (Los Alamos National Scientific Laboratories), Jean Lorre (Jet Propulsion Laboratory), Donald J Lynn (Jet Propulsion Laboratory), Walter McCrone (McCrone Associates), George Markoski (Nuclear Technology Corporation), Vernon D Miller (Brooks Institute of Photography), Roger A Morris (Los Alamos National Scientific Laboratories), Robert W Mottern (Sandia Laboratories), Fr. Adam Otterbein (Holy Shroud Guild), Samuel Pellicori (Santa Barbara Research Center), Giovanni Riggi (University of Turin), Fr. Peter Rinaldi (Holy Shroud Guild), Rev. John A T Robinson (Bishop of Woolwich), Ray Rogers (Los Alamos National Scientific Laboratories), Larry Schwalbe (Los Alamos National Scientific Laboratories), Diane Soran (Los Alamos National Scientific Laboratories), Rev. David Sox (British Society for the Turin Shroud), Kenneth E Stevenson (IBM) and Barrie M Schwortz (Barrie Schwortz Studios).

It should be noted that some lists available on the web (such as this one) name only the American participants. There do not seem to be any complete lists readily available, which is hardly surprising, given the fluid and informal nature of the group’s membership, but disturbing for a number of reasons. It is noticeable that all these lists pointedly omit Walter McCrone, who resigned from the team in 1980, claiming that threats had been made on his life for his sceptical suggestions that the shroud was a medieval forgery. They also omit participants with religious affiliations, often by using the weasel word “including” to introduce the list without hinting that there were other members. One has to wonder why this should be so.

The methods used by STURP did not include radiocarbon dating. When initially set up, it had a radiocarbon subcommittee (composed of Robert Dinegar, Ray Rogers and David Sox), but was not included on the list of authorised tests released on 24 April 1978 by Don Piero Coero-Borga of the Centro Internazionale di Sindonologia. A furious David Sox released the list of tests to The Times, which published it on the front page. Coero-Borga’s reasoning was that “the Pollen Test has given very positive results with regard to the age and history of the Shroud” and should be extended acrosss a wider area. This is, of course, completely wrong: the pollen can only be used to date the Turin Shroud if one assumes that it was in Palestine at the time of the crucifixion of Jesus, a completely circular argument.

John Jackson and Eric Jumper scanned photographs of the Shroud taken in 1931 using a microdensitometer (specifically an Interpretation VP-8 Image Analyser), a now largely obsolete instrument used principally in scanning astronomical photographs and biological samples. They claimed that their results produced data that could be interpreted in three dimensions. By 1980, the STURP team was drawing back somewhat from these enthusiastic conclusions, stating that “the phrase “three-dimensional information encoded in the image”, used by the original authors, has been misrepresented and sensationalised… the term itself is inherently misleading because it implies that a precisely defined mapping function is known. This is not the case; the reflected image densities provide only incomplete information… The results have not as yet suggested a particular image formation mechanism nor do they imply that a three-dimensional object was necessary to produce the image”.

Eric Jumper himself later said “The 3-D business doesn’t prove anything about the Shroud… it’s just an observation”. In other words, it’s a version of the well-known analyst’s maxim GIGO (“garbage in, garbage out”), meaning that the production of the image in three dimensions is a red herring, an example of data manipulation rather than of anything inherent in the data. Nevertheless, the wrong-headed claim of three-dimensional encoding continues to be touted by believers in the Turin Shroud’s authenticity as one of the most significant pieces of evidence for its origin.

Pollen analysis carried out by STURP failed to replicate the results obtained a few years earlier by Max Frei. The team was critical of his findings and did not produce any new pollen evidence. Nevertheless, supporters of the Shroud tend to cite Frei’s analysis, while glossing over the criticisms raised by the STURP team.

The face as revealed in Secondo Pia’s negative

The face as revealed in Secondo Pia’s negative

Techniques used to examine the ‘body image’ areas of the Shroud included photomicroscopy, X-radiography, electron microscopy, chemical analyses and mass spectrometry in an attempt to find traces of pigment. Pigments including alizarin, charcoal and ultramarine were found, but did not necessarily coincide with the position of the body image. Their presence remains unexplained, however. Walter McCrone’s results obtained from photomicroscopy of a sample from the body image found high concentrations of iron oxide and traces of a protein, which he interpreted as pigment and medium, but were ridiculed by other members of the team (some sources claim that his results have been refuted, implying that they have been proven wrong, which is not the case).

The results show that image is not painted. What is seen on the shroud is a chemical darkening of a starch and polysaccharide coating on some of the fibres: it is evidently not the fibres themselves that are discoloured, but something applied to them after manufacture. This could be something to do with the traces of protein McCrone detected.

The ‘blood stains’ were examined more thoroughly by STURP than the earlier study and were found to have leaked all the way through the cloth, indicating that they had once been liquid. Various tests, including ultraviolet fluorescence imaging, X-ray fluorescence imaging, transmission spectroscopy, reflection spectroscopy and chemical tests suggest that this was real blood; John Heller and a colleague, Alan Adler, found traces of what they suggested might be highly degraded haemoglobin on the tapes that McCrone had analysed, but they failed to convince the majority of the team. One tester, Baiama Bollone, has claimed to have identified its type as AB, which he claimed matched miraculously transformed wine in the Eucharistic Miracle of Lanciano, confirming that this was indeed the blood of Jesus. On the other hand, the colour of the stains raises suspicions that this is an iron-based pigment, as dried blood is brown, not red.

Giovanni Riggi, a chemist, found traces of a substance chemically resembling natron (Na2CO3·10H2O), a mineral used in Ancient Egypt as part of the mummification process. How this might have been used in a Jewish burial of the first century CE is not explained although, intriguingly, one of the conclusions of the STURP team was that the image had been produced by dehydration of the linen fibres. Sources of the mineral include a number of places in Italy, so its presence cannot be taken as evidence for a Middle Eastern origin for the cloth.

Two members, Kenneth Stevenson and Gary Habermas (the latter a professor at fundamentalist Jerry Falwell’s Liberty College), stated that the odds of the image not being Jesus of Nazareth were “one chance in 82,944,000”. Whilst fundamentalists are inordinately fond of quoting probability statistics about the unlikelihood of something happening by chance, they rarely reveal the basis on which their calculations are made, and this is no exception. It is such a precise figure that it instantly raises suspicion.

Nevertheless, the overwhelming public impression after the STURP study of 1978 was that the authenticity of the shroud had been demonstrated beyond all reasonable doubt. Still, there remained disquiet among many, including some members of the STURP team such as Bishop John Robinson, that radiocarbon dating had not been attempted. Sceptical outsiders were also concerned that the majority of scholars chosen to run the tests were from christian religious denominations with a vested interest in the cloth.

Radiocarbon dating the Turin Shroud

During the 1980s, negotiations to submit samples of cloth to Accelerator Mass Spectrometry dating, which requires much smaller samples than older techniques, were begun. In 1987, agreement was reached to test seven samples weighing no more than 50 g and tested independently in seven separate laboratories that would not be allowed to share their results. In the event, three laboratories were chosen (Arizona, Oxford and Zürich) and asked to perform several tests on each of four samples taken from one corner of the cloth, which had been carefully checked to be free from later repairs.

The sample dates (in years before present (bp) with likely error) from each laboratory were as follows:

Sample 1: Arizona (AA-3367): 591±30 bp, 690±35 bp, 606±41 bp and 701±33 bp.
Sample 1: Oxford (Ox-2575): 795±65 bp, 730±45 bp and 745±55 bp.
Sample 1: Zürich (ETH-2883): 733±61 bp, 722±56 bp, 635±57 bp, 639±45 bp and 679±51 bp

Sample 2: Arizona (AA-3368): 922±48 bp, 986±56 bp, 829±50 bp, 996±38 bp and 894±37 bp
Sample 2: Oxford (Ox-2574): 980±55 bp, 915±55 bp and 925±45 bp
Sample 2: Zürich (ETH-3884): 890±59 bp, 1,036±63 bp, 923±47 bp, 980±50 bp and 904±46 bp

Sample 3: Arizona (AA-3369): 1,838±47 bp, 2,041±43 bp, 1,960±55 bp, 1,983±37 bp and 2,137±46 bp
Sample 3: Oxford (Ox-2576): 1,955±70 bp, 1,975±55 bp and 1,990±50 bp
Sample 3: Zürich (ETH-3885): 1,984±50 bp, 1,886±48 bp and 1,954±50 bp

Sample 4: Arizona (AA-3370): 724±42 bp, 778±88 bp, 764±45 bp, 602±38 bp and 825±44 bp
Sample 4: Oxford (Ox-2589): 785±50 bp, 710±40 bp and 790±45 bp
Sample 4: Zürich (ETH-3882): 739±63 bp, 676±60 bp, 760±66 bp, 646±49 bp and 660±46 bp

This is an unprecedented number of samples, with one set from the Shroud and three control samples: the laboratories were not told which sample came from the Shroud and which from the control objects. Those from each sample are consistent, so they can be combined into means. Sample 1 therefore has a mean radiocarbon date of 691±31 bp, which calibrates to 1262-1312, 1353-1384 CE at 2σ (95% confidence); sample 2 has a mean of 937±16, which calibrates to 1026-1160 CE at 2σ; sample 3 has a mean of 1,964±20, with a calibration of 9 BCE – 78 CE at 2σ; and sample 4 has a mean of 724±20, with a calibrated range of 1263-1283 CE at 2σ.

What do these dates mean? Sample 1 was from the Shroud, sample 2 from linen from a Nubian tomb of the eleventh to twelfth centuries CE, sample 3 was linen from a mummy of the early second century CE and sample 4 was from threads removed from the cope of St Louis d’Anjou dated to 1290-1310 CE. There is therefore no question that the Shroud is not medieval; we can be 95% confident that the cloth was manufactured between 1262 and 1384 CE. The chances of it dating from the first century CE are so vanishingly small that they can be discounted completely. This did not surprise those who had always believed the Shroud to be a medieval fake, as the documents relating to its first known exposition c 1354×6 described above record it as having been made “recently”: the date fits well with the radiocarbon assay.

Reaction to the scientific testing

There was little public reaction to the 1973 tests, apart from Max Frei’s pollen analyses. These could be interpreted to mean that the Shroud had indeed once been in Palestine, giving hope to those who wanted it to be the actual burial cloth of Jesus. There are problems with the pollen analysis, though: the Shroud was regularly exhibited in the open air until 1931, allowing it to pick up air-borne pollen (indeed, this is what enabled Frei to trace its alleged journey from the Middle East via Constantinople to France). Species of plants producing the pollen that Frei had identified as Middle Eastern are also to be found in Italy, meaning that the Shroud could have gained this pollen since its removal to Turin. Frei had gathered the pollen by applying sticky tape to the surface of the Shroud without recording where he had done so and without assessing whether or not the areas from which he sampled might have been contaminated. Members of the STURP team rightly criticised his methodology.

The results of the STURP team were predictably conflicting and gave comfort both to believers in the authenticity of the Shroud and sceptics. Those who had welcomed Max Frei’s pollen analysis were enthused by the alleged three-dimensionality of the image (actually no more than an artefact of computer processing, as admitted by one of the analysts who had “discovered” it), the presence of real blood (although not proven to the satisfaction of all) and the lack of evidence for any technique that might have been used to paint the image (despite the acknowledged presence of a variety of pigments).

Sceptics sided with Walter McCrone’s discovery of iron oxide particles and protein (albeit in smaller quantities than he suggested), the debunking of Max Frei’s pollen analysis and the available historical data. With no consensus among the STURP team (and the well publicised religious conversions of a number of its members), the analysis had reached an impasse that could only be resolved by scientific dating.

The results of the radiocarbon dating were similarly divisive. The scientific community was relieved that the results were consistent: all four laboratories came up with near-identical results, while the determinations for the three samples of known manufacturing date were consistent with those dates. This gave great confidence in the reliability of the radiocarbon determinations.

Believers in the authenticity of the Turin Shroud were dismayed and began to speculate about how the radiocarbon dates might somehow be “wrong”. Perhaps the miracle of the resurrection had somehow altered the physical properties of the cloth, irradiating it and making it appear younger than it ought. Perhaps there was some undetectable contamination by microorganisms that were of recent date and present in such numbers that they altered the date (we can calculate the proportion of modern carbon needed to make a first century CE sample appear to date from the fourteenth century: physicist Thomas Pickett calculated it as around 67%, which would make those who prepared the samples very slipshod in their cleaning and, incidentally, slipshod to exactly the same extent in all three laboratories). Perhaps the cloth was contaminated by fibres from an otherwise undetected repair (the laboratories removed some cotton fibres from the samples they were given); there is now a rash of published papers arguing this view. Sheer weight of numbers does not mean the idea is correct, of course.

The Shroud of Turin Blog says that “[c]otton isn’t the contaminant here. It suggests the possibility of other contaminants”, which is a bit of a red herring. Cotton has been blamed for potentially contaminating the sample and as evidence that the piece removed for testing was part of a repair. The Shroud of Turin Blog’s author has made the a priori assumption that there must be contamination of the sample because he doesn’t want to accept the date provided by the laboratories. Bringing up “[m]adder root dye, aluminum products [and] gum” is not an answer. Ray Rogers found these materials (one of which is a pigment, incidentally, something that the Shroud of Turin Blog denies is present on the Shroud!) in two thread samples that were said to have been left over from those submitted for radiocarbon dating whist claiming that they are not present on the rest of the Shroud. They are.

Perhaps the alleged contamination is a result of manual handling over the centuries. Still, no matter what the source of contamination, it would have to be in the order of 67% modern material causing the contamination. Make it cotton from sixteenth-century repairs and the proportion of contaminated to original material would have to increase at a geometric rate. The idea that the samples were contaminated is simply not credible unless one assumes massive incompetence at all three radiocarbon laboratories, the same degree of contamination in all three samples and the same inability to remove any of the contaminants. This is just silly.

Chemist Roy Rogers proposed an alternative, chemical dating method based on the decay of lignin in the linen fibres, citing the absence of vanillin in detectable quantities. Using fibres allegedly left over from the 1988 tests, he claimed the test gave a date of between 3000 BCE and 700 CE, which is a very wide range of dates, but significantly older than a fourteenth-century cloth. Others have been unable to replicate his results. While there is clearly a correlation between lignin decay and age, the assumption that this takes place at a known and constant rate is unproven. The problem here is understanding the rate of loss of vanillin from the linen fibres, especially considering the effects of the fire that damaged the cloth in 1532. It may be useful in establishing relative age between two samples from the same environment (although this has yet to be demonstrated), but there is no evidence of its utility as an absolute dating technique.

All these proposals are post hoc rationalisations rather than something forced by the evidence. There is remarkable congruity of evidence for the date of the Turin Shroud: documentary, radiocarbon, textile analysis and art historical. These all point to the fourteenth century CE (or thereabouts), not the first century CE.

Further claims about the Turin Shroud

In 2009, a researcher in the Vatican archives, Dr Barbara Frale, announced that she had discovered faint writing on the Shroud while studying digitally enhanced photographs produced in 1994. In her book La Sindone di Gesu Nazareno, she goes further than the STURP team, which believed that it had identified several letters close to the head of the image, and counts eleven words in total in the same area. Some words are in Greek, others in Aramaic, yet others in Latin. She claims that among other things, there is the Greek phrase [Ι]ησου[ς] Ναζαρηννος ([I]esou[s] Nazarennos, ‘Jesus the Nazarene’) as well as a fragment reading …ιβερ… (…iber…), which she interprets as part of the name of the Emperor Tiberius (42 BCE – 37 CE). Describing the ‘text’ as a ‘death certificate’ glued around the head of the deceased, she interprets it as reading “In the year 16 of the reign of the Emperor Tiberius, Jesus the Nazarene, taken down at the ninth hour, after having been condemned to death by a Roman judge because he was found guilty (of inciting the people to revolt) by a Hebrew authority, is hereby sent for burial with the obligation of being consigned to his family only after one full year. Signed by…” (the name of the supposed signatory cannot be read).

Barbara Frale is an expert on medieval documents: she was responsible for the publication of the Vatican’s archives relating to the suppression of the Knights Templar early in the fourteenth century and has claimed that the order once owned the Turin Shroud. However, her work on the Shroud has not been well received, except by true believers. Some have suggested that the letters are imprinted from a reliquary laid next to the Shroud in the medieval period, which she dismisses. She claims that a medieval text could not refer to Jesus as “the Nazarene”, as this would have been “heretical”. It is also highly unlikely that the three languages she claims to read would be mixed in an official ‘death certificate’; although both Aramaic and Greek are found on ossuaries of the period, Latin is completely absent and was not used in official documents in the region. The ecclesiastical historian Antonio Lombatti has suggested that Frale’s ‘letters’ are just a product of pareidolia, the innate human tendency to make meaningful patterns from random splodges and dots. This makes a lot of sense. The ‘words’ have to be teased out from three quite different languages, never mixed in other contexts, in much the same way as ‘EVP (electronic voice phenomena, claimed to be voices of the dead) manifest as utterances in numerous different languages, each word an example of apophenia.

Back to basics: the context of Jewish burial customs

In 2009, it was reported that a genuinely first-century CE burial shroud had been discovered in the Hinnom valley in Jerusalem. This is the first discovery of its kind and provides the first material with which to compare the Turin Shroud. This shroud was found in a tomb that had been partly disturbed by looters, which is why Professor Shimon Gibson from the Israel Antiquities Authority excavated it completely. As usual, the looters were looking for saleable artefacts, such as ossuaries, and had left the shroud fragments as valueless.

The survival of the cloth is unusual and seems to have occurred because, unusually, the tomb was completely sealed with plaster, which had prevented the tomb from becoming damp. Furthermore, the relatives of the man buried in the shroud had not returned to gather up the strips of cloth for deposition in an ossuary. The reason for this appears to have been that the deceased had suffered from leprosy and tuberculosis, which were detected in DNA samples taken from the surviving bones.

The weave of the “Hinnom Shroud” from National Geographic

The weave of the “Hinnom Shroud” from National Geographic

So how do the characteristics of this certainly first century CE cloth compare with those of the Turin Shroud? Firstly, the “Hinnom Shroud”, as it may be called, is not a single piece of cloth. Rather, it consists of a mixture of woollen and linen cloths, stitched together into a patchwork, unlike the single piece of linen that comprises the Turin Shroud. There is also a separate piece of cloth to cover the face, which is what would be expected from what we know of Jewish burial customs of the period. Secondly, whereas the weave of the Turin Shroud is a type known as twill, a weave with a characteristic diamond pattern (denim is a cloth with twill weave), that of the Hinnom Shroud is a simple cross-weave. Twill was unknown in the Middle East until the medieval period, which has long been seen as a problem for the Turin Shroud’s authenticity as the burial cloth of a Jew of the first century CE. Now we have an undisputed shroud from the right time and place, it does not have a twill weave. Moreover, it conforms more to what we would expect from a Jewish burial cloth rather than to something a medieval artist might imagine one to have been.

The Hinnom Shroud consists of a patchwork of cloths with a separate piece for the head, all made in a plain two-way weave, quite unlike the Turin Shroud. Going back to the Gospels – our only sources of information about the burial of Jesus – we find that they mention not a single cloth but “strips of linen” (Luke XXIV.12 and John XX.5, both using the Greek plural word ὀθόνια, meaning ‘small pieces or strips of linen’). Supporters of the authenticity of the Turin Shroud are careful not to quote these passages, which show that the evangelists did not think of the body of Jesus as ever having been wrapped in a single linen cloth.

The image of the body on the Turin Shroud

In the discussion around the age of the cloth, the composition of the markings on it and the mechanisms that might have caused the image to exist, the art historical aspects are often overlooked. In the case of those who believe that the Shroud is a genuine relic of Jesus of Nazareth’s resurrection, there is no need; in the case of the sceptics who believe it to be a medieval forgery, the paucity of discussion is surprising. If, as they assert, the Shroud is the product of a highly skilled fourteenth-century artist, more effort should be made to find parallels for the techniques employed and the actual depiction of the body.

It has long been noted that there are anatomical curiosities. The neck, arms and hands appear too long for a normally proportioned human; there is no navel; the buttocks (probably the heaviest part of the body allegedly to have come into contact with the Shroud) are very poorly defined; the feet are badly delineated.

With some of these discrepancies, obvious solutions can be suggested. The arms and hands have been extended artificially to cover the genitals: it would be inconceivable for a medieval artist to depict the genitalia of the crucified Jesus (it was acceptable in pictures of the baby Jesus, though). The buttocks are given summary treatment for similar reasons of prudery. Moreover, unless the arms were tied together at the wrists, the arms should have dropped to rest on the elbows, either side of the body; there is no trace of ties (and this despite claims that the image is so prefect that one can make out letters on the coins allegedly place over the eyes following a distinctly pagan practice). The navel is not depicted because of a medieval theological controversy over whether Jesus (like Adam and Eve) would have had one; indeed, as the “second Adam”, Jesus was expected to be similar.

Another problem concerns the top of the head: it simply isn’t there. This is very difficult to explain if the Shroud had been wrapped around a real human body. Either it went tightly round the crown of the head, in which case the image of the front would merge seamlessly with the back, or there was a gap at the top, in which case the cloth would have dropped over the top of the head, attaching an image of the crown to the image of the front. Instead, we just see a gap between front and back images. This is completely implausible for an image formed by unknown means from a body wrapped in the Shroud, but entirely feasible for the work of a skilful artist.

Ian Wilson has attempted, in numerous publications, to show that earlier depictions of Jesus in art from the Roman Empire onwards have often been based on the image shown on the Shroud. Nevertheless, there are wide variations in the depiction of Jesus and only some bear a likeness to this one; it is just as likely (more so, in view of the other evidence), that the face on the Shroud was designed to look like familiar representations of Jesus.

Conclusions

As the Shroud of Turin Blog says, “[g]ood archaeology means considering all the facts, not just those that are convenient”; this is absolutely the case (although I would prefer the term “evidence” to “facts”, when we’ve already seen just how contentious some of the alleged “facts” of the case are). Some believers try to dismiss the documentary evidence and the radiocarbon dating, despite their mutual agreement; they also point to the lack of consensus about how the image was formed and make great play of its allegedly three-dimensional encoding.

The letter of Bishop Pierre II that mentions an inquiry by a predecessor is dismissed by the Shroud of Turin blog as a “hearsay claim — and that is all it seems to be, for no one was ever identified and no document has been found that recounts what a then dead bishop had supposedly said — has been largely dismissed by historians”, which shows both a massive misunderstanding of the poor survival of medieval documents and makes a sweeping claim without evidence. Historians have not, by and large, dismissed the report of Bishop Pierre II; it seems that only those who want to believe in a Shroud older than the fourteenth century have sought reasons to disbelieve it.

The Shroud of Turin Blog objects to my handling of the derived three-dimensional data from the Shroud. The blogger has advised me to have a look at a site that tries to explain the alleged three dimensional encoding in the image. According to its author, the Shroud image does not have the type of shading that is found in photographs or paintings: “[t]here is no direction to what seems like light. Something else is causing the lighter and darker shades. That is looks like light to us is an optical illusion” (spelling error in the original). What none of this reveals, of course, is that the three-dimensionality is not encoded in the image, as admitted by one of those who made the original claim, but is derived from it by a mathematical function that the analysts themselves determined. A different function would have given different results. This is data manipulation, not an inherent property of the Shroud’s image.

Another well known face rendered in three dimensions

Another well known face rendered in three dimensions from a two-dimensional image

Now, I’m no graphic artist, but even with limited photographic manipulation skills, I’ve been able to come up with the image on the right. Firstly, I plotted a well known monochrome photograph as a bump map; then I rendered it in negative; next, I applied a bit of perspective; finally, I turned it green (as it’s generally a green image of the face on the Shroud that is shown in an allegedly three-dimensional form). The results aren’t exactly spectacular, but they are approaching the nature of the picture derived from the Shroud. What I find especially interesting is the way that unevenness in the surface of the scanned photograph show up beautifully as three-dimensional. So, I have conducted my own brief experiment (I spent two minutes playing with the image) and found that this alleged property of the Turin Shroud is not as unique as is claimed.

The lack of consensus about how the image might have been formed needs to account for Walter McCrone’s 1998 explanation, that it’s a result of a very dilute vermillion and red ochre tempera, which sounds reasonable and would explain the thinness of the coating on the fibres. McCrone examined samples from the Shroud and identified the chemicals used. He also pointed out that the technique, known as grisaille, was common in the fourteenth century. I suspect that the thinness of the coating – and it’s significant that the blog claiming to detect Bad Archaeology here admits that it is a coating – is a result of the extreme dilution noted by McCrone (0.01% in a 0.01% gelatin solution: remember, these are the results of tests, not wishful thinking). The fact that Ray Rogers, whom The Shroud of Turin Blog quotes with evident approval, was unable to find any evidence for pigments using visible and ultraviolet spectrometry, infrared spectrometry, x-ray fluorescence spectrometry, thermography, pyrolysis-mass-spectrometry, laser­ microprobe Raman analyses and microchemical testing are effectively meaningless. Two pigments known to have been used in medieval painting, with a carrying medium also known to have been used, were found in one of the tests. That needs to be explained, not glossed over or simply denied.

I also wonder about the role of the natron. Given that the changes to the linen fibres involve ageing through desiccation and that natron is a desiccating agent, is there a link between the two? Might the image have been created by dusting the cloth with natron in areas the artist wanted to darken? Is this perhaps then enhanced by a very light application of dry vermillion red ochre? Lack of a liquid medium would prevent the pigment from entering the fibres but would enable it to coat it very thinly. The technique of tempera painting onto cloth is fourteenth century, the first record of the shroud is fourteenth century and the radiocarbon dates show that it was manufactured in the fourteenth century.

The result is that those who believe the cloth to be the burial shroud of Jesus of Nazareth have tried to dismiss the results of the radiocarbon dating. All manner of bizarre suggestions have been made, from irradiation during the miracle of Jesus’s resurrection to contamination by fungal spores of recent date. None of these excuses works. The shroud is medieval and those who believe otherwise are deluded.

Worthless claims of a second radiocarbon test

Stories began to circulate in March 2013 that a second radiocarbon dating of the Turin Shroud had been performed by the University of Padua. The dates obtained are said to be 300 BC ± 400 and 200 BC ± 500, AD 400 ± 400. Unfortunately, these are not radiocarbon tests, as I will explain shortly. Giulio Fanti, who conducted the tests, is a true believer in the authenticity of the Shroud. He has criticised the 1988 radiocarbon dating on statistical grounds, arguing that the presence of a statistical outlier in the results from the Arizona laboratory invalidates all the tests. This is plainly nonsense.

But what of his tests? As already indicated, they are not radiocarbon dates. They are assessments of age based on the degradation of cellulose over time. He measured samples of known age by Fourier transform infrared spectroscopy, Raman spectroscopy and mechanical tensile strength. He then took fibres alleged to come from the Shroud but actually of dubious provenance to come up with his dates. His methodology and results have been thoroughly debunked. Much as some hysterical commentators want to believe that these results are being deliberately suppressed, they are being ignored for the worthless unscientific nonsense they really are.

In conclusion

When those who wish to promote the Turin Shroud as a genuine artefact of first-century CE date, they must explain:

  • how Bishop Henri of Troyes was fooled in the mid 1350s by someone who claimed to have painted the Shroud;
  • why Bishop Pierre II of Troyes, the Avignon Pope Clement II and the de Charnay family accepted that the Lirey Shroud was an image and not the actual burial cloth of Jesus;
  • how the alleged contaminants in the fibres submitted for radiocarbon dating have produced dates that match so well the date of the Bishop’s alleged artist;
  • why there are traces of vermillion and madder on the cloth in sufficient concentrations to produce an image using the medieval technique of grisaille;
  • the role of the natron found on the cloth;
  • why the image on the cloth is anatomically impossible (the neck is too long, the legs are too long, the arms have not flopped to the side – which would have had the unfortunate effect of exposing the body’s genitalia);
  • why the cloth has not draped itself around the sides of the body but remained miraculously on a single plane for the imprint of the image;
  • why the weave of the cloth is one common in the European Middle Ages but not found on the only definite burial cloth of first century CE date to have been identified;
  • why the Gospels refer not to a single cloth but to ὀθόνια, ‘small strips of linen’ (Luke XXIV.12 and John XX.5).

These issues (and more) need be addressed if the Turin Shroud is to be demonstrated anything other than a medieval fake.