Comments on “The Shroud of Turin:A Critical Appraisal”
by Marvin M. Mueller
Published in Skeptical Inquirer Spring 1982
Mueller correctly notes modern science has roots in natural theology.
Early in the four-century history of modern science, a dominant
motive for doing “natural philosophy” was usually cut from the cloth of
“natural theology”—worshipping the Creator by studying and under-
standing his handiwork.
He correctly notes no relic has undergone more scientific study than the shroud.
Never in all history has a religious relic been subjected to such thorough scientific scrutiny.
He cites Jackson as stating:
An Associated Press report on November 20, 1979, stated: “The scientist who
led the team that investigated the Shroud of Turin last year says evidence
so far indicates that the linen did in fact wrap the crucified body of Jesus
Christ.” The report quoted the scientist: “All of us who were there, at least
all of those I talked to, are convinced that the burden of proof has shifted.
The burden is now on the skeptic. . . . Every one of the scientists I have
talked to believes the cloth is authentic.”
Mueller then makes the erroneous claim:
Science developed originally as an oasis of rational naturalism in the vast desert of superstition and supernaturalism that had existed since primitive times.
This is not true and Mueller self-refutes himself when he acknowledged science had its roots in natural theology. Practically all the forefathers of the scientific revolution believed in God. There was no impetus of having an “oasis rational naturalism in the
vast desert of superstition and supernaturalism” by any of the first modern scientists. This is purely another myth invented by skeptics to reinvent history.
Thus I wondered what
unique observations, what total failure of naturalistic hypotheses, could
have driven these men to embrace such a momentous break with scientific
Obviously he never read much on the papers produced by the STURP scientists. They conducted every conceivable test at their disposal to find a naturalistic explanation for the shroud. And these were not amateur scientists, but scientists from the top scientific institutions in the country.
In 1357 the Lirey cloth, proclaimed to be Christ’s burial shroud, was being
exhibited frequently for fees to large crowds of pilgrims from all over,
when a skeptical French bishop named Henri de Poitiers launched an
investigation into its provenance.
Interesting claim. What evidence does he show to support this? He has none. Yes, they did sell souveniers at the Lirey church for a brief period. But there’s no record of “large crowds” that visited this small church.
Clement considered the matter and issued a Bull, which, although
allowing exhibition of the cloth, ordered that it be advertised only as a
“copy or representation.” However, this directive was gradually forgotten,
and the proclaimed shroud came to be the most venerated relic in
There’s no evidence anyone ever received the d’Arcis memo or that it was sent.
Needless to say, this is not one of the customary ways of
wrapping a body; it is also contrary to the description given in the
Not sure what he is referring to. What was the customary way for Jews to wrap a body? Or is he referring to the customary ways of Egyptians to wrap a body?
Mueller admits the contact-transfer and vapor explanations are untenable.
And, as naturalistic explanations for the image—the contact-
transfer and vaporgraph hypotheses, for example—were in time shown to
be indefensible, skeptics, for the first time, found themselves in an uncomfortable position.
It is true it is only recent has interest in the shroud extended beyond the Catholic community.
The result of this was a slow but steady increase in scholarly interest in
the puzzle of the shroud in the early and middle decades of this century.
Nearly all of the interest, however, was restricted to Roman Catholics.
Ecumenical interest developed only relatively recently.
This discovery doubtless played a decisive role in persuading the hierarchy to
allow another, much more thorough round of scientific tests after the
shroud was put on public display in Turin in September 1978.
Mueller has so many errors in his guesswork of how STURP formed and how they were able to go to Turin to study the shroud. For the best account I’ve read on this, see John Heller’s book, Report on the Shroud of Turin.
published statements, it appears that nearly all of the new members joining
STURP at this time accepted this hypothesis as the only viable one in the
light of the evidence then available.
No idea what Mueller is talking about here. Who are the “new members”? When did they join? All of the members of STURP joined before their trip to Turin (except for one who was already in Turin). The scientists only concluded it was not an artwork after they conducted their study.
the old journalistic maxim that extraordinary
claims demand extraordinary proof was conveniently forgotten.
Actually the opposite. The TS is extraordinary evidence.
Mueller does do a good job summarizing the encoding of cloth-to-body distance:
First, an outline of the shroud image is carefully traced, full size, onto
a piece of cloth simulating the actual “shroud.” The cloth is then draped
over the reclining figure of a suitable human male volunteer (5’11”, 170
lbs.) so body parts on the simulated image are in contact with, or vertically
over, those of the volunteer. Then by optical techniques (more difficult
than they appear) the vertical cloth-to-body distances are determined for a
two-dimensional array of image points. Previously, the optical density
(darkness) of a photograph of the shroud image had been determined by
microdensitometry for a two-dimensional array also. Thus image darkness
can be correlated with cloth-to-body distance over a two-dimensional
field. This correlation turns out to be only fair, exhibiting a lot of data
scatter, but it does indicate a roughly exponential-type fall-off to near-zero
image-darkness in a little less than two inches. Jackson and Jumper then
draw a smooth curve (an exponential function in the early work) through
the region of the scattered data points and call this the “mapping function.”
But they also have to make allowance for the sag and drape of the
cloth by determining, for the same two-dimensinal array, the distances of
the cloth above the table top on which the human model reposes. (By
simple subtraction, one also has the shape of the upper surface of the
model relative to the table top.) This done, once they have the image
darkness for a specific point on the shroud image, they can mathematically
invert the mapping function to give the corresponding cloth-to-body
distance. From this procedure along with the drape-shape function, the
height above the reference plane of a point on the presumed human shape
under the shroud can be calculated. By doing this for all the points in the
two-dimensional array, they obtain a three-dimensional image reconstruc-
tion that can be either viewed isometrically on a computer-generated graph
or used to manufacture a statue of the “Man in the Shroud.”The resultant
three-dimensinal figure looks rather human but is somewhat distorted. To
make it look better, the mathematical drape-shape function is iteratively
changed—after all, no one knows how the alleged actual shroud might
have been draped in a tomb in Palestine two millennia ago. Indeed, the
mapping function itself is also modified to give a less-distorted human
But then he makes a strange claim that it points to a bas-relief, which he does not justify. Rather, a bas-relief would not have cloth to body distance encoding if it was pressed against the body.
The final three-dimensional figure then looks normally human
except for one thing: If the face is adjusted to have normal relief, the body
appears to be in bas-relief.
His main charge is circular reasoning was used by STURP.
The salient point is that the three-dimensional reconstruction method
depends essentially on circular reasoning, and the question of whether or
not the shroud ever contained a human form is begged.
But this charge is misplaced since STURP is not claiming the depth encoding is evidence there was a real body involved. The issue is what is the origin of the depth encoding, whether it is a real or fake body that was involved.
For another, STURP, carrying out many trials with lasers of diverse wave-
lengths and pulse-widths, has not been able even to come close to
duplicating the microscopic shroud-image characteristics by lightly scorch –
This might’ve been true in 1982, but the discoloration has been duplicated in 2005 through UV lasers.
He cites Nickell’s bas-relief rubbing of Bing Crosby.
Nickell’s first rubbing was done using an available bas-relief—a four-
inch oblique (nonfrontal) view of the face of Bing Crosby. STURP applied
its mapping function to a half-tone magazine photograph of this image and
found it wanting. As expected, it exhibits the three-dimensional informa-
tion it picked up from the bas-relief, but STURP’s three-dimensional
reconstruction from it is badly distorted in places. Whether or not this is a
proper and significant test is highly debatable, but nevertheless STURP
has made much of this “failure”.
Mueller acknowledges the bas-relief has problems with it and hopes in the future improvements in the technique will come.
It is clear that STURP’s conclusion is unwarranted at this time. First.
the number of variations of the rubbing technique are enormous—who
could say that one of the many could not pass STURP’s procrustean “3-D
test'”.’ Second. Nickell has by now improved his technique. He has a larger,
frontal-aspect bas-relief that gives rubbings bearing a distinct, but not
perfect, visual resemblance to the face of the shroud image—see the
comparison in Figures 2 and 3 between a negative of the shroud image and
one of Nickell’s images. Who could say that a few more trials, with
appropriate changes in succession, might not result in an image closely
simulating the shroud image in appearance and in local consistency of
And as far as I know, there has been no further improvements by Nickell that has simulated the shroud features.
Mueller mentions Michael Baden:
All of these claims have recently been challenged by an outside
pathologist, Michael Baden, deputy chief medical examiner of New York
for Queens County. Baden claims that nearly all of Bucklin’s assertions
concerning anatomical and pathological features of the shroud image and
“bloodflows” are either dubious or incorrect, and on the basis of the image
characteristics themselves it is very probable that the shroud never contained a corpse.
I see brief references to Baden at different places, but I cannot find what Baden actually claimed.
Mueller mentions the discoloration of the fibrils, but has no alternative explanation for it.
Its unanimous conclusion is
that the straw-yellow color of the image fibrils was probably caused by
dehydration of the cellulose. With respect to inorganics, STURP’s x-ray
fluorescence tests find an appreciable amount of calcium as well as
detectable iron rather evenly distributed across image and clear area
My opinion is that, while real blood could well be present, STURP
has not established that it is. More important, it has no case at all for
asserting that the “bloodstains” are entirely blood.
Again I refer to John Heller’s book where he details how he and Adler studied the blood samples to conclude it was actual blood. You can also read their official report:
Mueller (who is a physicist that has not studied the blood samples) can only offer his opinion that Heller and Adler (who are both chemists that have studied the blood samples) have not established it is real blood.
My opinion is that, while real blood could well be present, STURP
has not established that it is.
STURP cannot refute the contention that an appreciable fraction of the
“bloodstains” could be due to an artist’s pigment composed of iron oxide.
Actually, STURP acknowledges iron oxide could come from paintings that have been blessed by being pressed against the shroud.
Further support for this contention comes from the picturelike appearance
of the “bloodstains”; this would seem impossible if blood on a corpse dried
in contact with the linen and this was later pulled free.
I entirely agree the blood stains could not be “picturelike” if the cloth was pulled off from an actual body.
Of course the putative artist would be likely to use some real blood in
producing the “bloodstains” anyway, and so the presence of blood is not of
great importance in deciding authenticity.
This is highly unlikely. For one thing, there was no artist who painted with blood to make accurate blood stains in the medieval times (or even recent times). For another, how was an artist able to make the blood still be red after centuries? How was he able to paint the blood first and then put the body image on?
What is of crucial importance is
whether the “bloodstains” are at least partly composed of some pigment
foreign to blood.
This is not disputed really by anybody. But this is an admission by Mueller the cloth contains real blood.
There are only three classes of possibilities for the image formation: by
human artifice, through natural processes transferring the image to the
linen from a real crucified corpse, or by supernatural means. Of the third,
not much can be said, because then all scientific discussion and all rational
discourse must perforce cease.
Agreed, however one can still have rational discourse outside of science.
But a lot can be said about natural processes. In terse summary, they
can be ruled out definitively by the quality and beauty of the shroud image.
However, since natural processes involving contact transfer and vapor
transport have long been discussed as possible mechanisms, we should
really lay them to rest here. In this, STURP would concur wholeheartedly.
And then there is an
inescapable fact of geometry: Even if the cloth were to be somehow closely
molded to a full-relief (body or statue) for contact transfer to take place,
then when it was taken off and flattened out the image would be grossly
Also agree and would add this refutes the bas-relief.
He agrees it could not have been painted. But then suggests it could have been “cunningly painted”.
the shroud image was not painted in any ordinary sense of the term is by
now beyond dispute. But what about “cunningly painted”?
scorching from a moderately hot bas-relief cannot be ruled out with
certainty, but it runs into serious trouble with image superficiality as well
as scorch fluorescence. In its favor is the fact that low-temperature
scorches do result in dehydrated cellulose.
Yes, light scorching from bas-relief can be ruled out because of distortions when flattened as he mentioned earlier. And as he notes, the body image does not fluoresce in UV light.
But there are also other methods of dehydrating cellulose, and these
can be employed in a hypothetical hypothesis of human artifice, as we shall
see, which STURP cannot refute at this time.
The methods that he proposes can be refuted since fibers that are colored are right next to fibers that are not colored. This doesn’t make sense if sunlight, oils, or juice is used.
Lately, they’ve been calling the mechanism of image
formation “a mystery.” This is somewhat misleading; it implies that there is
no viable hypothesis at this time. The one given above is not yet established
experimentally, but it does deserve to be taken seriously.
Correct, the bas-relief has not yet been established experimentally.
In private, several
of the Los Alamos members will admit that they have not really ruled out
Nothing is completely ruled out. It certainly can be the case a naturalistic explanation can fully account for all the features of the shroud. And skeptics are more than free to come up with a compelling argument. But for now, the conclusion is there is no viable artistic method.
The main difference between 1977 and the present is that much
more is known now, and STURP members are more puzzled and much
And this is still true in 2023.
Also, and this cannot be overemphasized, STURP nowadays
is hardly monolithic—it is really an assembly of individuals holding rather diverse opinions.
Not sure what is Mueller’s point. I can also turn it around and say it cannot be overemphasized that skeptics are hardly monolithic and hold to diverse opinions.
However, ex-STURP members Stevenson and Habermas in their
recent book regard the radiation-scorch hypothesis as proved and as
God’s belated gift to believers.
Habermas has never claimed the shroud proves the resurrection. He was also never on the STURP team.
as well as for
showing in 1974 that the formerly celebrated “priceless” Vinland Map of
Yale University (supposedly a pre-Columbian map of the American east
coast) is actually a modern forgery on ancient parchment.
Actually, people also dispute this as well:
STURP gave McCrone, who was still a
member at the time, thirty-two of the tape samples for analysis.
This is what McCrone claims, but if you ask the STURP members, McCrone was never a member of STURP. Also, it was Rogers who gave McCrone the sticky tapes, who did it without the prior authorization of STURP.
STURP admits that there are some iron oxide particles on the image fibrils
but claims they are of insufficient number (actually, areal density) to
contribute appreciably to the visual image coloration.
And even McCrone admits he cannot scientifically demonstrate the particles were sufficient to account for all the blood stains.
After reviewing the evidence on both sides, I tentatively conclude that
ferric oxide contributes less than about 10 percent to the overall image
intensity; but more experiments should be done.
What is crucial is whether McCrone is right in
claiming that iron oxide particles are found only in the image and
“bloodstain” areas and almost never in the clear areas.
There were few iron oxide particles found overall, even on the samples from image areas. What seems to be more of a correlation is it is related to the water stain patterns. Heller talks about this in his book.
The red particle aggregates I mentioned are quite numerous in the
“bloodstain” areas, where they contribute to the redness of the visual
There is not enough iron oxide to even account for the red color.
So modern experimental science in its full-bore, megabuck aspect has now
been used to confront the most venerated relic in Christendom, and the
outcome is still far more tentative and debatable than most observers
Which would be quite amazing if it was the work of a medieval artist that has been able to confound scientists that have intensely studied it.
That the Shroud of Turin is not a painting in the standard sense
has been demonstrated unequivocally; that it was not produced by unaided
natural processes is virtually certain.
All that now remains is to decide
between human involvement in “cunningly painting” it and its provenance
through means totally unknown and unimaginable to science—and there-
fore possibly supernatural. Needless to say, the issue at stake here is one of
epochal potential implication.
Because modern science has never had to introduce a supernatural
hypothesis (whatever that might mean, since scientific method is abso-
lutely and essentially based on naturalistic explanations) scientific investi-
gators eschew any paranormal or supernatural explanation—even for
something that has long been venerated as the actual image of Jesus Christ.
According to the strict definition of modern science, I agree science should have no involvement with supernatural explanations. But the logical inference given all the data is an explanation beyond science.
But what is a skeptical inquirer to make of all this? He will naturally
try to formulate a human-artifice hypothesis consistent with the known
principles of art and science and also consistent with the observations of
STURP, McCrone, and Nickell. Such a hypothesis has been discussed in
the previous section, but in a rather disjointed manner. To recapitulate
briefly here: First, the image-forming method will probably have to be
based on some kind of imprinting technique to impart photonegativity
automatically—most likely rubbing, a la Nickell. Second, the rubbing
medium must be dry or semi-solid (to limit image depth), must contain a
coloring pigment (probably an iron earth), and must largely disappear
(being nonproteinaceous would help, relative to STURP’s tests) by reac-
tion with cellulose over time and temperature, or perhaps by evaporation,
leaving finally only dehydrated cellulose fibrils coated sparsely with iron
It appears certain that STURP cannot rule out this hypothesis, or
similar ones, at this time.
Mueller already admitted “the Shroud of Turin is not a painting in the standard sense has been demonstrated unequivocally”, but then he does special pleading by saying a bas-relief was done in a “cunningly painted” way.
First is the fact that the media do frequently distort
statements to serve their needs.
And we saw that with the 1988 C-14 dating.
the strong religious inclinations of nearly all of the STURP membership
doubtless play a role here.
Ad hom and also unsubstantiated accusation. As a matter of fact, they were intentional to avoid religious factors to affect their study.
With the benefit of hindsight, what was
their main mistake? It was, in part at least, neglecting to include card-
carrying “skepticians” in their working group.
You mean someone like Nickell who has never worked as a scientist?
Of course it is easy to criticize now. In reality, very few skeptical
scientists would have been willing, even if invited, to sacrifice years of
family and vacation time for the dubious reward of (in their opinion)
finally finding the obvious—an obvious devoid of much real scientific
Mueller does not really understand the motivation of why these scientists decided to join STURP but is just guessing.
Ideally, of course, the shroud investigation should have started with radiocarbon
dating, which might then have saved an enormous number of man-years—
both within and without STURP.
No, ideally testing should all be non-destructive, not destructive like C-14.
Another point that really needs to be settled is the serious disagree-
ment between McCrone and STURP over what is or is not on the cloth.
Replication, the tedious and costly price that science pays for objectivity, is
probably the key to resolving this controversy. In the many areas of
disagreement, the procedures of McCrone and STURP should be repeated
(adding random sampling and extension to larger shroud areas) at a
suitable independent laboratory, ideally under the close scrutiny of both
McCrone and a STURP representative. It would indeed be surprising if
this didn’t settle the controversy once and for all.
This is a serious challenge. STURP, having the resources and expertise required, should be eager to accept it.
Mueller has no understanding of how STURP was financed. Actually many members of STURP self-financed their involvement with the shroud. So it wasn’t like they got a huge grant with an endless spigot of money.