Why is Salisbury Plain so steppe-like? A prelude to another look at the Stonehenge mystery

Hello. Sciencebod is back again, after a break of some 4 months (I've been researching the Turin Shroud - see previous posting and link to my specialist site).

My new interest is Stonehenge - like... what was it for, and how did the bluestones get there, all the way from the Preseli hills in west Wales - reckoned to be 135 miles or so as the crow flies?

Non-colour coded

 Spot those famous  'bluestones' (colour-coded)

I've been getting acquainted with some of the facts and rival theories on Dr. Brian John's splendid and friendly site (and a paperback copy of his book is due to arrive in a day or two).

Stonehenge, just west of Amesbury, is situated a short way south of the approximate centre of Salisbury Plain, the latter being described as one of the largest tracts of chalk grassland in western Europe.

Straightaway that seems an odd description to this science bod. I thought the climax vegetation in Britain was supposed to be forest. What's holding Salisbury Plain back, so to speak? Or did it used to be forest, and if so, been unable to regenerate?  If the latter, then why not, apart from all those MOD tank tracks?  OK, so this may seem to be peripheral to the enduring mystery of Stonehenge, where I am still developing ideas, some of which agree with Brian John's, some of which do not (at least for now, but we may converge once I have read his book).

For starters, let's take a look at satellite pictures of Salisbury Plain, courtesy of Google Maps. I have started with a picture that includes most if not all the Plain, and then homed in progressively on the bare region in the centre. The fifth and last picture in the series looks for all the world like a green oasis-like area, but I shall resist the temptation to call Salisbury Plain a desert - not most people's idea of SW England. But I do believe the description 'steppe-like' is fitting and will be exploring this curious geology and/or history of previous land use/misuse in future posts. (Relax, MOD, it is not you I have in my sights, but yours and my ancestors, going back thousands of years).

Picture 1 (click to enlarge) : Note the bare butterfly-shaped area, most of which is left of centre - Salisbury Plain

Now zooming in (labels  and more pictures later)...

Picture 2 (above):

Picture 3 (above):

Picture 4 (above):

Picture 5 (above):




Even without Stonehenge, Salisbury Plain would be weird. Is its un-English- looking steppe-like weirdness (not always apparent if passing by on the A303) part of the reason why Stonehenge came to be where its is?  More to come...


Late addition: 11 May 2012. It has been suggested on Brian John's site, indeed by the blogger no less, that it is the military activity on the Plain that prevents regeneration.  Here's a photograph from Google maps that suggests otherwise.

 Notice the way that the tracks avoid the trees, but that the trees themselves look stunted. Those trees are not happy trees. Now why would that be I wonder. Prepare for another "out-of-the-box" hypothesis soon, one that adds a third possibility over and above bluestones being transported by human or glacial means.

Here's a clue: note Stonehenge. Note nearby grove of trees, happily growing in an otherwise unpromising chalky field with no real soil to speak of...

More to come...

And finally, missus and I visited Stonehenge and a bit of the Plain today. I'll write a short post later. In the meantime, it was good to see Brian John's book on display in the visitor centre.

My own copy was waiting for me on the doormat when we got back. I now have some serious reading to do (and may have to retract some or all of my  "out-of-the-box" ideas" re the local geology  - we shall see...)

Update: Sunday May 13 : here's the way my thinking ("hypothesizing") is going.

Look at the labelling in red that I have added to a standard textbook diagram. (Ignore the rest of the diagram re laccoliths etc at least for now).  I'm not suggesting, of course, that any of the Stonehenge monoliths are dikes that sprouted at that precise spot - but there may have been dikes within, say, a 10 mile radius that provided some or all of those 'bluestones' - about as heterogeneous a bunch of dolerites, rhyolites etc as one can imagine, that just happen to match some that are found  130 or so miles away in the Preseli hills. As the diagram makes clear - dikes/dykes (for once I prefer the US spelling) can in principle come up close to the surface (and become exposed with erosion) pretty well anywhere in principle, depending on the size of the underlying pluton and/or batholith.

Why do I think there is a sill under Salisbury Plain? That was not an ab initio hypothesis - quite the opposite in fact. It is/was an attempt to understand the unusual characteristics of the Plain where English landscape is concerned. (The Plain is described in wiki as one of the largest areas of 'chalk grassland' in Europe, aka calcareous grassland). My starting point was that there is something unusual about the drainage characteristics that make the Plain a difficult habitat in which deep-rooted trees can get established. An impermeant sill, maybe at a slant that allows quick run-off of percolated rain water, might provide an answer. More later.

Further afterthought: there's a well-known phenomenon in probability theory - namely that if you have 20 or so people in the same room, the chances of at least two people sharing the same birthday is surprisingly high  (said to be 50% (p =0.5) for 23 people in the same room ). I cannot help but wonder if the same effect is not operating with respect to the so-called cause-and-effect correspondence between the dolerites of Stonehenge and the Preseli Hills of west Wales .If there's a sizeable heterogeneity ("range of types")  within the bluestones at Stonehenge, and a sizeable heterogeneity of the bluestones at Preseli, then there is an enhanced probability of finding at least one close match. But that should not be an occasion for premature celebration unless one has looked at the heterogeneity of bluestones everywhere within a 200 mile radius of Stonehenge...

Update: Monday 14 May:

Here's a picture of Preseli rocks in situ erupting from the ground as tors (showing their origin as intrusive igneous rock that has become exposed by erosion):

Preseli  - Carn Menyn - presumed source of the Stonehenge bluestones

See the interesting objection made to the supposed Preseli/Stonehenge connection made by a commentator on the 'FreeRepublic' site from which I obtained the above picture (merely searching Google image files for ...  preseli bluestone... And it's geological, to do with quartz intrusions and fracture planes....

http://www.freerepublic.com/focus/f-chat/2772069/posts

To save you, dear reader, the trouble of locating the particular comment, here's the key section from a kindred spirit:

..I also observed that where columns or pillars ARE present in the bedrock outcrops, when they are released and fall onto the scree they almost inevitably break across, because of transverse fractures or other weaknesses related to quartz veins etc.
So away with that particular piece of nonsense. I am quite convinced that there would have been NO reason for Neolithic tribesmen to "target" Carn Meini as an ideal quarry site. There was nothing special about the spotted dolerites (they outcrop over a very wide area), or about the stone shapes, or about the ease of access or stone extraction (other sites would have been easier).
For the best part of a century archaeologists have been indulging in special pleading with respect to Carn Meini. Once HH Thomas announced that that was where the spotted dolerites came from, one generation after another has sought to find justifications or reasons for the "choice" of the site. It's all there, in the literature......

To which yours truly would add - those pillar-like blocks from the same or related pluton or batholith could have erupted elsewhere, and have had a similar chemical composition petrology if the conditions at the other place of intrusion and final exposure had been similar. The crucial factor with an intrusive rock that forms when magma crystallised before reaching the surface is the rate of cooling. The slower the cooling, the bigger the crystals of feldspar etc. Who's to say that  dike A from Pluton1 did not crystallize at approximately the same rate as dike B from the same pluton, with 130 or so miles separating the two dikes?

Here's another picture I came across (the High Force waterfall, River Tees) which refers to dolerite sitting on top of limestone (the latter a close relative of chalk needless to say, both being calcium carbonate, CaCO3, albeit of differing chemical and biological source material):

The caption in the source refers to the dolerite being visible as darker rock (though it all looks much the same to me except for that single rectangle immediately above the top of the fall). Irrespective,  there ARE precedents for English dolerite making it through beds of calcium carbonate.... Maybe there are some closer to Wiltshire than NE England...

And finally, here's a geological map of England and Wales:

The red star shows the approximate position of Stonehenge, situated on Cretaceous chalk. But what lies beneath that chalk, shown in green (apart from magma if you go deep enough?)

One final post from this science bod on why he thinks the Shroud of Turin is a medieval fake

(Update: added 10th April 2012:  My continuing research and ideas on the Turin Shroud are now to be found on two specialist sites, the more important of the two being this one.


 This site is somewhat past its sell-by-date now as far as the Shroud is concerned - and needs re-writing anyway. Those who are only here for the Shroud should click on the link above.)

 Let's start with some cut-and-paste from one of Dan Porter's sites.   There is a graphic and an excellent account of what it shows (and, more to the point, does not show):

Computerised representation of the Shroud image with 3D enhancement

Here is the accompanying text:

"Look at a full frontal picture of a man. The tip of his nose approaches white and the depth of the recesses of his eyes are darker. The roundness of his face from his cheeks towards his ears is progressively darker.  At first glance, the face on the Shroud of Turin appears to be such a picture. It isn't.
 

How do we know this? All regular pictures, be they paintings or photographs, represent light coming from some direction and being reflected towards our eyes. The eye of the painter or the camera lens is a proxy for our own eyes. The reason the recesses of a man's eyes are darker than the tip of his nose is because less light gets to into the recess. Image analysis shows us that this is not so with the facial image on the Shroud. There 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.

... with special computer software we can plot the data, the brighter and darker tones, as an elevation. That is exactly what we can do with the image on the Shroud of Turin: plot it as an elevation. 

Let's be clear: You can not plot a regular photograph this way. Nor can you do so for a painting, even a brown and white painting. You can do so with a precise copy of the Shroud, however. 

Not only does this show that the image on the Shroud is not a photograph or painting, it shows that something extraordinary occurred to form the image".

***********************************************************************************


I shall return later and suggest how the original Shroud image was produced, and why it gave rise to the peculiar pattern of light and dark that we see in the green computer-enhanced image above:
First, let's go to the original introduction to this post:

They say a picture is worth a thousand words. Well, here are two pictures that I consider make it 99% certain that the Shroud of Turin is a medieval fake. You may need to consult some of my previous posts on the subject  - some 20 in all - to appreciate the background - which relate an accumulation of steadily growing evidence from simple kitchen experiments - but I shan't clutter up this final post with a lot of verbiage - the pictures tell all.
The first is a picture of a small metal trinket I brought back from Ghana, which I heated over a cooker ring, then thrust face down into a sheet of linen placed over a tray of sand. It shows the scorch mark left by the artefact.

The second is a picture I took after just 30 minutes of playing with an unfamiliar bit of software, one which anyone can download off the internet - which  converts 2D images to 3D representations.

3D metal object with scorch mark left on linen

 From 2D scorch mark (previous picture) to 3D visualisation

 (This was my very first experiment with the software -  if you feel like further tweaking then I will provide a link to the free software)

NEW ADDITON:  I WAS ASKED ELSEWHERE IF THE SAME 3D EFFECT WAS OBTAINABLE WITH A FAINTER IMAGE. THE ANSWER IS YES!

Hot from the press!

The scorch mark could be said to contain "3D-encoded" information, right? Based on the intensity of the scorched-on image, right? Just like the Shroud of Turin image right (scorched on?) one that has millions of folks the world over mesmerised?

Take your pick from the 20th century photo album of computerised reprocessing of the Shroud image

What a wonderful thing is this modern computer imaging technology  - able to enhance in glorious 3D a supposedly first century AD image of the crucified Christ. What's more, it was captured, would you believe it, on his burial shroud in his tomb, at the very instant of Resurrection, by a mysterious flash of light - or even uv or x-rays - according to some Shroud scientists?

Nuff said methinks. I shall use the Comments sections to add, or clarify, or respond to reasonable criticism. Message to internet trolls: please don't waste your time - or mine - since abuse will neither be tolerated nor published.

sciencebod aka newsjunkie aka ColinB

Colin Berry MSc PhD (Biochemistry)

emails to: sciencebod01@aol.com

Postscript: arising from comments, another test for my model has come to mind, but it's a little involved. Are you sitting comfortable? OK, I shall begin:

Suppose one took a bust of a person and chose, let's say, 50 points at random, and then, with the aid of camera and computer, converted the image to a relief map, showing contour lines linking points at the same height above a reference line.Suppose one then put that data into a 3D image analyser to produce the kind of image obtained for the Man on the Shroud? How closely would they compare?  Is the Shroud image really a relief map based on elevation?  I don't think it is, so here's what I propose. Take the same bust, and at each of the 50 points that were selected for relief mapping attach a sensitive electronic pressure monitor. Then push the bust with attached monitors into linen/sand and get a pressure reading for each of the 50 points. That can then be used to plot "isobars", i.e. lines joining points of equal pressure. Then analyse that image for 3D properties. It's my guess that "pressure" map would give a better match to the Shroud image than one based on supposed elevation.


Here's another perhaps simpler way of looking at it. The most intense scorch mark in my sand bed model is not necessarily from points that are highest, e.g. the nose but from points that present square-on to the sand when one presses in, giving the greatest pressure, the closest contact between linen and hot metal, the greatest intensity of scorching..

Look at the Shroud image again. Am I not right in thinking that it is the flattest parts that give the greatest image density, regardless of elevation? That is why those closed eyes are so prominent, despite being  relatively low. That is why one does not see the sides of the face, not because they are particularly low in elevation terms, but because they offer little or no resistance to the linen/sand.

I believe the Shroud image should be re-scanned to see whether it fits a relief model better or worse than one based on angle of plane surface relative to an applied force. (I'm aware there may be potential cans of worms in making this comparison, but it seems at least worth flagging up the idea now).


Something else to consider:  Others, e.g. the Bad Archaeology site, have pointed out that the image is "anatomically impossible", that for example "neck is too long". There is a simple explanation for that in my sand bed model. When the metal effigy (bronze statue or whatever) is pushed into the linen/sand the cloth is first pressed against the "square on" features of the face, and then turns a right angle at the end of the chin, when it is then pressed lightly against the underside of the chin before it hits the next plane square-on surface, i.e. the neck.

 Note the two crease marks at the chin and just below. One is dark, the other light, suggesting the cloth is folded in opposite directions, as might be expected if forced to change directions twice.


But here's the crucial point: when the linen is then removed and laid flat, the neck will look too long because the top portion represents the underside of the chin, which can be a considerable length (it is about 10 cm on both me and the missus.)

Oops. I said I would  attempt to explain the peculiar 3D image (green) at the top of the page. OK, here we go. Observe closely where there is shade. The shade is under the eyebrows, under the eyelids, under the nose, under the lips etc. It's almost as it there had been a source of light above the face that had cast into shadow any feature that was beneath an "overhang", no matter how small. Well, once could suggest thatthe face is an image in the harsh glare of an overhead light, captured by some kind of photography, but I do not believe photography had any role to play, and (curiously) those who think the image is in some way or another miraculous have failed to comment on the "top-lighting" effect.

Here's my explanation: all the shaded regions represent parts of the face on a 3D replica, e.g. bronze replica of the crucified Christ that would not be able to compress the linen onto the sandbed, due to being in a plane that is vertical to the one that gives compression. Consider the nose: a small part of the bridge of the nose, pressed into linen/sand, would encounter resistance as the sand is compressed, and would leave a branded imprint. But the underside of the nose, with the nostrils would not. The sides of the nose, being slightly angled, would leave a small imprint, but not a major one.

 It is time that the Shroud image was thoroughly re-examined to see if the image density corresponds to my sand bed theory, and is a mapping of contours in relation to compaction pressure, and with it the degree of close contact between hot metal and linen to result in differering degrees of heat-scorching.


So much then for the Turin Shroud where this site is concerned. I have created (Feb 2012) a new WordPress blog that will report any further results and ideas I may have on the subject:

Spotlight on that Shroud of Turin Without All The Hype

Why does the Turin Shroud appear to have scorched-in crease marks? Tell-tale signature for medieval forging?

 The standard model - linen draped loosely over the body contours

I had an idea this morning while out on a stroll. Most of the Shroud literature refers to a cloth that is loosely draped over the supposed body of the crucified  Christ. That is then the starting point (all too often) for some frankly amazing speculation about an image being projected onto a cloth (Quite how that is supposed to happen without an imaging system – converging lens etc – or a source of (non-supernatural) radiation is anyone’s guess). Some even seem to imagine that loosely draped cloth being at least momentarily and miraculously spread out flat immediately prior to capturing the image, or so it would seem when one encounters references to "foreshortening" and other effects borrowed from photography and optics generally.

But my model, or rather John Jackson’s plus a supporting bed of sand (the latter being my finishing touch –  does not have a real person, 1^stcentury AD or otherwise, but a metal replica, e.g. a bronze statue, one that is heated and then thrust DOWNWARDS with a degree of force into the linen with that all-important backing bed of sand. 

Now think about it: a loosely draped-over sheet creates at most gentle folds, without creases, but being forced into a bed of sand where the cloth gets pushed first this way, then another, is likely to create creases. And those creases, or at any rate some of them, might be captured for all time, so to speak, were they to be forced to make contact with hot metal and then scorched along the new apposed edges. Where would such creases be most prominent? Surely over those parts of a bronze where there is the most abrupt change of relief, e.g. at the end of the chin? 

I could not wait to get home and have another look at the Shroud images. Somewhere at the back of my mind was a recollection of having seen just such creases.

Hallelujah – exactly as predicted. There are indications of prominent crease-like marks in the head region alone – one at the base of the chin, and one where the temple turns through almost 90 degrees to become the top of the head (the latter being un-imaged – worthy of a post in itself). 

Negative image (as seen by eye). Note prominent line at chin level, and a fainter one at the top of head

Here's a comparison of negative v positive images. Both lines are now clearly visible.

Obviously I am restricted to available images of the Shroud, but is there any other useful information that might be gained by looking at those crease-like marks at greater magnification?

Here’s a close -up:

 Seems to be a double-track, like a railway line, rather than a single line

Further magnified

(Note the interesting extra kink in the middle that widens the "track")

Notice that the mark is a railway track-like feature with two outer dark lines and a lighter space in-between.(That's "railroad track" in US parlance).  The dark lines are presumably the result of the same scorching process that produced the main image - the one I call thermo-printing. The intermediate light area is presumably a non-scorched intermediate zone.   Already, and possibly prematurely, I found myself wondering about the geometry of creasing, i.e. which is “inside” and which is “outside” on that crease. Having done so, back-of-envelope style (I reserve the right to have second thoughts) and this being a blog that describes a journey, not the final destination, which incidentally I shamelessly edit and re-edit, I decided to go for broke and add a last paragraph.

Here’s a little piccy I’ve just knocked off on MS Paint to indicate how think those two crease (?) marks could have arisen in a sand bed model. The linen has got rucked slightly to form invaginations, i.e. “creases” in common parlance (sorry ladies, but that seems the most apt appropriate terminology) the U-shaped  interiors of which are protected from conducted heat by slight separation from hot metal, so would appear as that white strip between the two parallel tracks when the cloth is flattened out. 

 Modelling the origin of two scorched-in creases in the Turin Shroud: green - head of heated bronze effigy; white- linen shroud; brown - scorch mark (note two interruptions); blue - cold spot in crease; yellow - sand bed

The aim is to illustrate beyond any shadow of doubt that a 3D object pushed into sand-supported linen can produce scorched-in creasing around major and abrupt changes in relief, and importantly ONLY at those regions.

Conclusion: I regard those two crease marks as evidence for the image having been formed by applying force, consistent with my thermo-printing model, especially with a backing bed of sand. The scorched-in creases would seem to me to be inconsistent with any model that has fabric loosely draped over a 3D subject – living, dead or inanimate. Now please refer again to the title of this post.  Are those creases not a signature for the Shroud having been produced as a forgery, using a replica, e.g. bronze statue, of the crucified Christ?

Postscript: some further predictions that could be made from the sand bed model (although the fourth, a late addition, is perhaps more by way of explanation than prediction):

1. The weave would show greater separation, i.e. stretching,  of yarn fibres  - warp and weft - over the prominences of a metal effigy - the bridge of the nose etc.

2. There could be adhering or impressed sand (?) particles on the reverse side of each image region.

3. Image regions could have traces of metal oxides, eg those of copper and tin if a bronze effigy had been used

4.The ventral (frontal) image would have to inconveniently end at the tip of a toe with no surplus sheet beyond the foot  - since an overlong sheet would have risked imprinting both sides of the feet (think how it would respond to pushing into a sand bed)!  It does seem odd that the Shroud ends precisely at a foot in both ventral and dorsal views, which is somewhat unexpected, is it not? Would one not expect a burial cloth to have had sufficient surplus at the two free ends to permit easy sewing up.  The total length (over 14 feet) of linen was surely sufficient to allow that?

I have always felt there was something not quite right about the position of the feet, right at the end of the Shroud).

Does the Turin Shroud carry a designer label – showing how it was made (immediate contact with a HOT body)?

I have been comparing the results of my “sandpit” modelling of the Turin Shroud (see two previous posts) with a magnified image from the Shroud fabric.

Here they are, one above the other:

 "Modelling" of Shroud image by thermal imprinting off a metallic 3D object

 Close up of image-region on Turin Shroud

Here is the text from the original article  (my italics)

"Close up view of the Shroud cloth. Each thread is hand spun from cellulose fibers from flax. Notice golden color on some of the fibers. Spectral and chemical tests show that fibers are coated with a thin carbohydrate file. In places this film has turned a golden-brown color that seems to be the result of caramelization or a Maillard reaction.

The coating is superficial. It is only found on the outermost fibers at the crown of the threads. Pulling back individual fibers reveals that there is no image color below the outer threads."

Notice any resemblance?

Observe how the thermal footprint on my linen sheet accentuates the weave pattern on the linen. 

 Note selective scorching of  the more superficial "crown" loops, especially in less-strongly printed areas.

Then look at the Shroud image, and read the account that accompanied it. Am I not correct in thinking that we are looking at the same highly superficial, selective scorch phenomenon – that it is only the most exposed part of the thread – the so-called “crowns” - where weft loops over warp, or warp loops over weft, that is scorched.

 Know your jargon - warp versus weft

Here is a diagram off a Google image file that I have touched up with MS Paint to show those "crowns" that are most exposed and vulnerable to scorching by CONTACT/CONDUCTION. (Ignore the knots)

Parts of the same fibre, immediately adjacent, separated by a fraction of a millimetre, escape scorching.

What is that if not a signature in both cases of scorching by IMMEDIATE CONTACT, requiring CONDUCTED heat from the hot body. Radiant heat from the same body-   at least below red heat -  is not sufficiently intense to  scorch, the latter requiring direct and intimate contact. Is the pattern I describe not a "designer label" in a manner of speaking - and I mean a human, not celestial designer-  applying mundane earthly physics and technology... ?

Strangely there is a paucity of images available from the internet on magnified close-ups of the Shroud, but there seems no reason to doubt that the Shroud image bears a close resemblance to the one in my experiment, showing highly localised crown-scorching, with negligible scorching deeper into the weave. 

This would appear to me (and earlier Ray Rogers  ) to virtually exclude any mechanism for image-production that depends on radiant energy, regardless of the region of electromagnetic spectrum used – microwave, infrared, visible, ultraviolet, x-ray or gamma ray. 

Paolo di Lazzaro and ENEA colleagues please note. Put your uv excimer lasers away – or at any rate use them for the originally-intended project. Some might think you are doing for Italian science what your countryman Captain Schettino did for Mediterarranean cruises, going way off course, and ending up grounded on rocks.

 

Those highly superficial scorch marks, corresponding with those weft and warp crowns,  ones which others maintain as challenging the very foundation of  modern science - simply indicate highly intimate ("tactile") contact with the fabric.

But how can a hot human body, alive or dead, scorch linen without scorching itself?  It cannot, obviously, unless one engages in fantasies about spontaneous combustion (which would have set the Shroud alight).

It seems self-evident that Shroud image was made by close and intimate contact with a hot inanimate body. As before, I suggest that it was a bronze(?) statue of the crucified Christ, or possibly customised bas reliefs – one for the front, one for the rear, possible even separate ones for face, arms etc.

There’s more I could say on the details, implications, directions for future research with crucial tests of rival theories – but I shall stop here for now and invite comments.  Comments are the lifeblood of blogs.  Oh, and may I remind some folk that science buzz  is a blogsite, with no ambitions or pretensions at being a dry and/or turgid scientific account, albeit with the loss of some "authority" - a drip, drip sometimes working as well  - and more gently - in the long term than a sledgehammer. This blog exists to highlight GOOD science, and to expose BAD science... (regardless of religious side-issues).

Postscript added Feb 20: I thought it would be interesting to put the scorched weave photograph into a 3D imaging program. Here's the result:

Before turning up the relief gain control:

And after ...

Moral: there is no "science" here. All you see is the result of the (clever) software performing a mathematical transformation. Remember that next time you are presented with the 3D rendering of of the Shroud image, rather than the original "negative" with those staring eyes and that curiously flat facial image that ends abruptly at the cheekbones left and right, with front and rear aspects of a supposedly crucified body but no sides etc etc...

A step-by-step guide to faking the Turin Shroud (on a miniature scale - but it's the principle that matters)

Here's what I used to start with - a 3D artefact (Ghanaian trinket), a bed of moist sand, a pair of pliars . Didn't need the spatula... Note the result of the previous experiment (linen stretched over heated face-up trinket, instead of face-down towards linen/ sand)

I then placed a square of linen over the sand tray, and pushed the trinket face down into the linen/sand

Here you can see the indentation left in the linen/sand when the trinket is removed in preparation for heating. The indentation is a guide to where to place the heated trinket into a pre-prepared cavity (but I might try using level sand next time).

Here is then trinket being heated. A sample of linen is used to test its temperature (note that it has charred at the end, meaning the trinket is now hot enough to scorch linen, probably overheated in fact (but in this pilot trial I deliberately set out to produce a 'extreme' end-result that would photograph well)

Here is the hot trinket being pressed down into the linen/sand. At this stage there is no evidence of scorching.

Here is the trinket being removed. It stuck half way - on account of charring at the nose...

 

 

 First view of full thermal 'footprint' (correction - 'faceprint')

Trinket fully removed, revealing a thermal print of most of its features compared with original.  Note the way that the cheeks show up - that did not happen without the sand , i.e. when the linen was pressed down on the trinket face-up. Note the amount of fine detail picked up - the beading on the eyebrows etc. Note too that the image is left-right reversed (like a photographic negative), see the blemish on cheek as a marker.

 Here was a second run, using a less-strongly heated trinket. There are two scarcely visible scorch images - side by side - to the left of the trinket. Granted this photograph  is lacking in  visual impact, but is a better model for the faint image on the Shroud. With trial-and-error it might be possible to reproduce the precise image intensity of the Shroud of Turin.

Postcript: I see elsewhere that my idea has been criticized on the grounds that it contravenes the Universal Fluoresence Principle  ;-)  The latter in case you are not aware, dear reader, is based on the observation that while the 1532 burn marks on the Shroud fluoresce under uv light, the Shroud image does not. Ipso facto, the Shroud image cannot represent a scorch mark.

Strange, don't you  think that one tiny observation should be held to constitute a veto on any idea that the Shroud image is a scorch mark? Now had the original observation been backed up by generating scorch marks by a variety of means, and showing that all, without exception, fail to fluoresce under uv, I might have had greater respect for the idea that the Shroud image could not be a scorch.

Maybe it's the result of having had a strong grounding in organic chemistry as part of my first degree (in Biochemistry) backed up by subsequent research experience - most of it postdoctoral - that I am hugely unimpressed by that single obeservation re the 1532 scorch mark. 

What causes certain molecules to fluoresce under uv light? It is usually due to the presence of a number of  C=C double bonds in the structure, in linear and/or cyclic regions of the structure. When these chromophores absorb a quantum of uv light, there is often a number of ways that the energy can be subsequently released when promoted electrons drop back between quantised energy states, and in a conjugated diene system it is sometimes the case that the energy difference corresponds to the frequency of light in the visible part of the em spectrum.

So what might encourage the formation of fluorescent chromophores ('fluorochromes') in a fabric that is primarily cellulosic?  Answer: pyrolysis, i.e. heating in the absence of oxygen, because the chemical dehydration reactions (elimination of the elements of water, i.e. hydrogen and oxygen atoms in a 2:1 ratio) produce double bonds in the absence of oxygen.  But pyrolysis is almost certainly the appropriate description for what happened to the Shroud in the 1532 Chambery fire, where the Shroud was at least partially protected inside a silver reliquary that was engulfed in a fierce fire: the Shroud would have been heated  in the presence of limited oxygen, so double bonds and fluorescent properties were highly probable.

In short, one cannot use the Chambery fire as a basis on which to propose that ALL heating and charring results in fluorescence, least of all that the Shroud image is NOT a scorch. The latter could have been formed in the presence of ample oxygen.

It's time the "Universal Fluorescence Principle" was laid to rest, or alternatively put to a more rigorous chemical test. 

I might even try doing it myself sometime, given that ultraviolet lamps are not difficult to come by...

Second postscript: Here's a quickie experiment that makes two points: firstly that top-printed images (upper row)  are lacking detail compared with those made with a sand bed (lower row), and secondly that any degree of image intensity can be obtained by using a progressively cooler artefact (left to right):

Click to enlarge

Third and final postscript:

How many times recently have you come across this bit of pseudo-scientific twaddle in the Shroud literature?:

"The Shroud image is "extremely thin, one-fifth of a thousandth of a millimeter ... corresponding to the thickness of the primary cell wall of a single linen fiber" . Clearly no medieval or earlier forger could make even a single mark on linen that thin, let alone create the image of a man, front and back, on a linen sheet, of that extreme thinness."

Portion of an illuminated manuscript

 Er, one fifth of a thousandth of a millimetre is 200nm. Has the writer never heard of medieval illuminated manuscripts? Does he not know how the gold was applied?  Answer: as gold leaf, usually on the tip of a brush. The typical thickness of gold leaf?  Yup: 200nm   ;-)

The method I describe here does not of course require applying any pigments or other chemicals.  One uses conducted heat to alter the surface layer of carbohydrate molecules, which may be cellulose, or, in the view of Raymond Rogers, some kind of starch or simple carbohydrate coating. 

The effect of heat is to produce chemical dehydration, i.e. elimination of the elements of water, introducing double bonds into the carbohydrate(s) that cause the scorched linen to absorb appreciably more light at the shorter wavelength (blue) end of the visible spectrum. The scattered blue-deficient light, primarily red and green, is then perceived by the human eye as yellow or pale brown.

Comments invited...

How was the Turin Shroud faked? First experimental test of my sandpit theory

They say one picture is worth a thousand words. Well, here are just two  pictures for starters showing an extreme scorch image produced by my sandpit theory (see previous post).

 Heat 3D metal object. Use a fragment of linen to test temperature (deliberately made high for this experiment to produce an 'extreme' example of a thermal footprint).

Press the heated artefact into linen spread over a tray of moist sand. Then remove the object to reveal the thermal footprint. Shown here half-removed (excessive charring under the nose made it stick at that point).
That's the bed of sand you see intruding on the right. The sand makes all the difference when thermo-printing off a 3D object.

Conclusion:  my 'sandpit theory' for how the Turin Shroud was produced  has been confirmed to work - at least in principle. Details can come later (as will a fuller series of photographs taken during the above experiment).

For the moment, I'd simply say that one can obtain much fainter, more superficial images, comparable to the one on the Shroud of Turin, by heating to a lower temperature, and applying less pressure when impressing the 3D object into the linen/sand.

Equipment required: A 3D object made of metal (I used a trinket bought off a street-trader in Ghana), a source of heat (e.g. an electric ring on a cooker),  a shallow tray filled with moist sand, a square of linen (I used a portion off a decorator's floor sheet), and a pair of pliars with which to grip the hot object.

Discussion: I suppose one could call the image a 'thermal footprint' (or maybe that should be 'faceprint' in this instance). 

Will it be shown to have 'encoded 3D information' if scanned, digitized and displayed on a VP-8 image analyser?  Probably yes, is my guess, depending on what one means by "encoded" and "3D"

I personally see no reason why the 'thermal footprint' above cannot be rendered in 3D, in the same way that a photograph of a boot print with a ribbed sole in mud could be made to resemble a forensic scientist's 3D plaster cast of the same after computerized image manipulation. There's nowt mysterious about converting 2D images to 3D representations, just as long as one realizes one is dealing all the time with artefacts, at least if the initial object (boot, metal trinket, bronze statue even of the crucified Christ)  is an artefact.

My new sandpit theory for how the Turin Shroud was produced - as a medieval hoax

 The basic principle - thermal imprinting  from a 3D object

(ed: things have moved on a bit since writing this post. For a more up-to-date account of my theory, see this later post, link  and the one preceding it link)

ed: a lot of the step-by-step photographs have mysteriously disappeared from this post. I will endeavour to restore them ASAP.
The technique is essentially one of 'branding' (yup, as onto the hide of cattle) but the 'branding iron' was more probably a bronze statue - which did not need to be red hot to create a superficial scorch on linen.

This is intended as the briefest of summaries. I propose using my own comments section to flesh out the details, but only in response to queries. In the absence of comments my time is probably better spent in  further experimentation  (continuing the work I have described in previous posts on thermo-imprinting or thermo-stencilling). 


Essence of the new model:

1. It uses a statue or bas relief of a crucified Christ - the kind of icon that would have adorned (if that is the correct term) many a medieval church or cathedral.

2. A shallow sandpit (US: sandbox)  is made with fine dry (ed. or maybe moist?) sand and levelled off with a rake.

3. The sheet of linen is stretched over the top of the sand and smoothed out. The linen may have been impregnated to make it more receptive to acquiring a heat-imprinted image (think "invisible writing" that uses dried-on  lemon juice or similar).

4. The statue is evenly heated in a kiln or oven until a test shows it to be hot enough to make a yellow or brown impression, i.e. 'scorch mark',  on a side-sample of the linen.

(Whether one calls it a scorch or not is a matter of semantics that can be discussed later. Certainly it does not have to be hot enough to degrade or scorch bulk cellulose per se, except perhaps for a highly superficial imprint).

5. The heated statue is then placed face-down horizontally onto the linen, and pressed down lightly.

 Except for awkward bits like the feet (see later) the statue is probably pressed no more than a cm or two into the sand, just sufficient to imprint as a light scorch the most prominent frontal features of the statue onto the linen, with little of the side features that might otherwise later give distortion when the cloth is removed and flattened.

The image would of course be a "negative", but that has nothing to do with photography, primitive of otherwise. The technology here is better described as thermal-imprinting by direct contact, relying mainly on heat conduction rather than radiant energy..

6.  When a satisfactory image has formed of the ventral (frontal) side, the second unused half of the sheet is positioned over the newly raked sandpit, and the process repeated for the dorsal (rear) side of the statue.

7. What about the blood stains - getting them correctly positioned etc? That can be arranged by a slight modification of the procedure.


It requires a "dry run", or more correctly a "cold run". Firstly, the cold, unheated statue is pressed onto the cloth  so as to penetrate the sand a little, leaving an indentation in both the sand and the linen. The statue is then carefully removed, and blood is then applied to the appropriate parts of the anatomy, as judged from the indentation.  It may be left to clot and dry first. The statue is then taken away and heated, and then deposited carefully back into its original indentation to ensure consistent alignment, then pressed down a little more into the sand in order to get a good impression.

8. Created in this way, I believe the image would meet some subtle criteria that so far have not been fully achieved, e.g. in Jackson's work with his bas-relief models (see earlier post).

I believe a balance can be struck that can achieve a good compromise between a shallow bas-relief and a fully 3D statue.The compromise gives enough relief to account for 20th century "3D-encoded information" - which if the truth be told is really just an (over-hyped) analogue- to-digitized impression of 3D, ie differential scorching- to-computer-aided graduated relief.  The dynamics of the pushing process, ie. - the gentle pressure on the statue, impressing it into the fabric and into the receptive cushioning sand to achieve progressively greater contact between cloth and hot metal is what helps to achieve a softer-focus more natural effect.

9. Because the statue is pressed downwards into the sand, i.e. at right angles, that would account for the so-called "directionality" of the image-forming process.

Attempting to explain the latter with radiation and projected images has been problematical, in the absence of lenses, concave mirrors, collimating systems etc., none of which are credibly medieval or indeed achievable today

10. This procedure might also explain some of the curious - or at any rate unexpected - features of the Shroud, e.g. the somewhat elongated fingers.

  Those fingers  (to say nothing of those "too good to be true" blood trails on forearms and that celebrated  "mechanically-correct" nail wound through "wrist").

That could be the result of a "sliding effect" of those hot fingers (one of the the first parts of the statue to hit the fabric) during the first few moments of pressing into the sand. It might also explain why the soles of the feet are so prominent on the dorsal image, despite their being out-of-horizontal plane, since the sand-moulding influence forcing fabric against metal would be largely indifferent to plane.

  

Why are the soles of the feet (even if blood-stained) so prominent in the left hand image (dorsal view), with subject's back to linen? What had been holding the linen so close and tightly apposed to them at the instant of image-imprinting? A bed of supportive sand, banked up maybe?

 To get a better idea of how soles come to be imprinted, and how they look on the flattened sheet, imagine yourself lying down on a sheet with muddy boots, first with heel-only contact, then imagine you ask someone to raise and then press the end of the sheet against the muddy soles to leave an imprint. Then imagine how the imprint will look when you get up and view the flattened-out sheet from above.


Comments - premoderated - are invited, but ad hom attacks will not be tolerated (or published)   If posting as "anonymous" please append an initial or two.