Colin Berry’s idea is untenable, and heat cannot produce a superficial coloration

imageAfter Colin Berry posted his statement about image formation, referenced here, I personally requested comments from members of the Shroud Science Group. This is Paolo Di Lazzaro’s answer to me and other SSG members who might not be expert enough in physics to understand why Colin Berry’s model (without experiments) is untenable. Now with Paolo’s kind permission those notes to SSG members are being published here:

Dear Dan and All:

I checked the idea of Colin Berry in the website you quoted.  In short, from a physics point of view, his model is untenable, especially concerning the depth of coloration. Let me explain why.

Berry wrote: “The scorching will initially be confined to those parts of the fabric that are in immediate contact with the hot metal; no air gap is permissible, since radiated heat will not scorch white linen. What is more, the scorch will be confined to the outermost fibres of the thread, because the scorch will tend remain trapped within the first-encountered fibres, rather than being able to “jump across” to adjacent fibres. Why is that? It is because the resistant cellulose cores that are unaffected are able to conduct away heat rapidly, bringing the temperature of the hot template down to below that which will induce scorching Is it realistic to suppose that cellulose fibres could conduct away heat without themselves becoming degraded? Yes. I believe it is.”

It is quite easy showing the above assumption is wrong, and it is one of the few cases where it is faster doing the experiment than to explain the theory. According with a paper quoted by Berry, the onset of pyrolysis in hemicelluloses is at about 220°C.  We have heated a 5-cents euro coin at about 230 °C in contact with a linen cloth. Just 5 seconds after the coin reached the max temperature the whole cross section of threads in contact with the coin was colored.  After15 seconds all the thickness of the cloth was colored and the round shaped image of the coin appeared on the opposite side. After checking in our Lab, we repeated this easy and small-size experiments in the RAI3 TV studios (GeoScienza) to demonstrate that heating linen cannot give a superficial coloration. See starting from the minute 16:30.

After the experimental demonstration, let’s approach the basic elementary physics that explain why the idea of Berry is untenable, and heat cannot produce a superficial coloration.

The hot metal transfers energy(heat) to the primary cell wall (pcw) of the linen fibrils by contact. From a microscopic view, transferring energy by contact means the hot (i.e. fastly moving)atoms of metal hit hemicelluloses molecules transferring momentum, thus increasing both amplitude and velocity of the motion of hemicellulose molecules around the equilibrium position (centroid). As a consequence, hemicellulose increases its temperature.

In the regions of contact between pcw and cellulosic medulla, we still have a transfer of heat by contact, like in the previous metal-pcw case. The temperature of the medulla will increase.  In the region where there is no contact (e.g.,a small air gap between pcw and medulla) we have heat transfer by irradiation.In fact, every material emits radiation having a spectrum peaked at a wavelength which depends on its temperature: the higher the temperature, the shorter the wavelength. This is the well known phenomenon of the black body emission, governed by Planck’s law, Wien’s law and so on (first year exam for students of Physics, Mathematics, Chemistry, Engineer).

As an example, at 20 °C the walls of a room emit radiation with a broad spectrum, peaked in the far infrared at about 10-micrometers wavelength. In the case of hemicelluloses at 200 °C the pcw emits infrared radiation peaked at 6,1 micrometers. In the case we are considering, the 6-micrometer wavelength will interact with the cellulose of the core of the linen fibril (medulla), exciting vibrational levels of cellulose that decay in heat thus increasing the temperature of the medulla.

In addition, a well known optics law tells us the penetration depth of the interaction between radiation and medulla cannot be smaller than the wavelength, that is, not smaller than 6 micrometers in this case. This fact alone explain why infrared radiation cannot produce a superficial coloration of fibers.

By the way, it is not possible that “the resistant cellulose cores that are unaffected are able to conduct away heat rapidly” (see above Berry’s statement) because of elementary fluid dynamic equations (a classical engineering problem), of a not convenient area/volume ratio of cylinders (elementary geometry) and because Berry assumes a exothermic pyrolysis of cellulose, that is,by definition, a runaway process, extended in time.

In summary, when heating a linen cloth by a hot metal in contact, well known physics models foresee the pyrolysis of the whole fibers and threads, and this is exactly what we observe in the experiments.

Useless to say, it is all the approach of Colin Berry to find a middle age technology able to create the Shroud image that is hopeless: just consider the half tone effect.  It could not have been made by medieval forgers because they would need a modern microscope to observe and then control their micrometric-scale coloration.

All the best


18 thoughts on “Colin Berry’s idea is untenable, and heat cannot produce a superficial coloration”

  1. Nice experiment, and easy to do, Dr. Lazzaro. Thanks.

    I suppose the next obvious experiment would be: how about heating the coin up away from the cloth and then place it down on the cloth for 1, 2, 3, 4, 5 seconds, then 10s, then 15s etc. Getting a series of scorching
    It seems as though it should be possible to catch a partial scorch, no?

    1. Nice comment Art. I’ve just said much the same on my own site (like he should have tested lower temperatures). Is Dr.Lazzaro seriously suggesting that a scorch is all-or-nothing, with no means of fine-tuning the colour intensity?

  2. “In addition, a well known optics law tells us the penetration depth of the interaction between radiation and medulla cannot be smaller than the wavelength, that is, not smaller than 6 micrometers in this case. This fact alone explain why infrared radiation cannot produce a superficial coloration of fibers.”

  3. I wasnt sure why they set the arbitrary time of 5 seconds, but I suppose to manoevre a big hot statue up and down might take 3 seconds minimum. Does the hemicellulose pyrolyse at a lower temp? I suppose you could try the minimum temp and say 3 seconds, see what you get.

    1. Yes, obviously if you’re trying to lower a metal statue at 220°+ C into a cloth on a sand bed, and press it down enough so that it makes contact with all the features, it’s going to be in contact with it for more than 3 seconds. And the parts that stick out the most are going to be in contact for longer and exert more pressure, and thus burn deeper. And you’re not going to have perfectly even pressure and contact time across the whole statue either.

      1. Good point, Deuce, though potentially you could have a cold pre-run to get the space in the sand ready (though that itself has drawbacks because the moment you have a prepared negative shape in which to sink into, you are losing any potential pressure differential against the cloth to get the features distinguished).

      2. It’s funny… I was thinking of mentioning this exact point to colin a couple of blogs ago. One must consider that some areas of the body/bas-relief would have distances of maybe 8+ centimeters difference, meaning high areas would receive substantially more heat transfer then lower areas. But using Deuce’s idea of cold runs to form the image in the sand first could eleviate this issue, but then raises other issues such as it producing partial ‘side-images’ off of areas such as the hands arms, neck etc, which we do not see. It would require substantial changes to the ‘cast’ and multiple attempts to alleviate this problem, putting more doubt to this method being attainable.


      3. Ron:

        Yes, you’d get side images from forming an indentation with a cold run, and like ArtScience pointed out, the even bigger problem is that you’d completely lose the 3D effect by having all parts of the statue exert the same pressure for the same amount of time.

  4. It’s subjective I know, but if I was allowed just a couple or so words with which to sum up the character of the image it would be “cardboard cut-out”. That’s on account of its overwhelming (to me) 2D character. But that is only to be expected in a sand bed model, because the parts that would imprint best would be those that resisted passage into the sand, i.e. that were by and large in planes parallel to the surface of the sand, with least tendency to “burrow in” and thus greatest tendency to compress the sand under them. The sides on the other hand, with planes more normal to the sand, would image poorly, of course, as indeed they do, through failing to compact sand, resulting in little pressure of sand/linen on surface contour. But then I would say that, wouldn’t I?

  5. The notion that one cannot produce progressively fainter imprints on linen off a hot template is of course ridiculous – commonsense alone should tell one that. But Dr.Di Lazzaro et al demonstrated themselves to be spectacularly lacking in the commonsense department when they decided that uv laser beams could tell us anything useful about the Shroud image.

    Enough of that. I prefer energetically- relevant physics and chemistry – the kind that won’t have Faraday spinning in his grave.

    This morning I tried a different approach, which I have just reported on my own site. Here is a photograph of the result:

    selective scorching of a superficial one-cell thick layer

    A sheet of epidermal cells, with their cellulosic/hemicelluosic primary cell wall (PCW) just one cell thick from the inner scale leaf of an onion was dried overnight. It was then briefly “branded” with a hot metal template (a pencil sharpener) producing an intense scorch mark. The underlying linen was largely unaffected, except for a couple of point locations, one of them corresponding with a protruding screw head on the template. In fact, the minor marks on the linen probably represent baked on onion epidermis, being at least partially strippable with adhesive tape.

    When the still-hot template was parked to one side (bottom of picture) it produced a second scorch on the linen, with that central screw head again being imaged.

    There is nothing remotely surprising about this result – namely that one can get selective scorching of a superficial cell layer by BRIEF application of a hot template. Alternatively,one could have used a cooler template, and either applied more pressure, or prolonged the time of contact or both. With three variables to play with, one could produce an image that was at the limit of visibility. I would fully expect that image to be confined to the primary cell wall – intrinsic to flax cells, or as here an “imported” sheet of cells with their PCW.

    I believe this result to be fully consistent with the thermal-scorching/hemicellulose/PCW theory for Shroud image formation. In fact it was predicted by that theory, which must surely lend further credibility to it. Sorry Dr.Di Lazzaro, but nothing – absolutely nothing- in the post above has – to my way of thinking – any bearing whatsoever on the theory.

    link to the full posting of my onion experiment

  6. Stop Press: even if this posting is somewhat past its sell-by date:

    There is an exceedingly easy way of disposing of Dr.Di Lazzaro’s objection, as I have just demonstrated at home, and reported as a postscript (the fourth!) on my most recent post:

    how to avoid reverse-side scorching

    One simply places a wad of damp linen underneath to act as a heat sink.

    I have posted three new photographs – the first to show the thermal imprints on the top surface, the second to show the absence of rear-side scorching, at least behind the light tan-coloured images (heavy black coloured scorches do show through on the other side, needless to say), and the third to show that the top side images can be processed to display “encoded 3D information”.

    Who says that the Shroud image defies any known science? Anyone who thinks that should read up on polysaccharide pyrolysis, hemicellulose v cellulose, and the three methods of heat transfer – conduction, convection and radiation. They should realize that in the absence of focusing or collimation hardware, there can be no central role for radiation of any kind, least of all ultraviolet and other short wavelengths (Dr.Di Lazzaro and ENSA colleagues please note).

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