Saturday, July 5, 2014

Are we there yet?

Here's what I posted as a comment just a few minutes ago to

Click to enlarge
Pilgrimage poster

Projected price: 40,870 (sharing, ex-Jhb; subject to currency fluctuations, air travel price fluctuations. calculated at R11/$).
Includes: Flights ex-Johannesburg (incl. airport taxes), accommodation with breakfast and dinner, lunch in Holy Land & Jordan, transfers, travel insurance, travelling on air-conditioned buses, English-speaking tour director, entrance fees, border taxes.
Excludes: Tips, hotel taxes, visa, lunches, personal expenses.

Let's see now. Assuming that's 40,870 South African rands, and applying the given exchange rate of 11 rands per dollar, that works out at approx $3,378 for a 14 day trip, flights  from J'burg included, which is $265 per day. That does not seem excessive cost-wise for so professional looking a pilgrimage package, especially one that is led by an archbishop no less (I see he ran one last year too).

What seems excessive to this pair of eyes is the use of a "reserved viewing" of the Shroud of Turin to paying customers, indeed, flagging it up as a highlight of the tour, when the same relic/icon (take your pick) is kept securely locked away from public gaze (including that of scholars and researchers) the rest of the time.

Am I the only one to think that what we see above is scarcely any different to the things that Martin Luther railed against (selling of indulgences etc)?

Nuff said. Back to the science. My comment enlarged:

Click to enlarge

Oops. It doesn't seem to enlarge on my screen. Here's what I said:

Roll up, roll up. See the $hroud of Turin (reserved viewing). But view it simply as an icon, no extravagant claims please.
Research update: I think I know how the TS image was (or might have been) made in principle, and am working hard to convert principle to practice.
Clue: a whole-body 'death mask' can be re-cast to make a trough-like bas relief in heat-conducting bronze. Place the hollow shell-like template face-down onto linen. Half-fill with quicklime. Then add water. Wait for steam, then press down into linen. Result: a 'thermochemical impactograph'.
This info is brought to you free of charge.

Converting principle to practice is proving a bit of a bugger, if you'll pardon my French. But we're working on it...   Nothing ventured, nothing gained. At least my latest refinement of the 'scorch hypothesis', narrowing it down to a 'thermochemical scorch hypothesis' should demonstrate that science (my pet subject) is not lost for answers. You see,  it's not just about science, is it?  It's about technology too. But without a time machine, how is science supposed to fathom the precise technology that was employed?

Those who taunt science and scientists for not being able to explain the Shroud image are essentially resorting to the 'God of the gaps' argument. 

There may or may not be a God - maybe we'll never know for sure until there's a Second Coming. But we can continue to explore the claims made for the authenticity of the TS by applying the methods of science - and maybe a little imagination too. It's sussing out the technology that is the real bugger...

New addition: Sunday 6 July

A mixture of quicklime and water generates enough heat to scorch linen when in direct contact (see previous postings). The practical problem is to convert that thermochemistry into an image-imprinting mechanism. Yesterday I had the reaction mixture inside a brass container, the latter pressed down onto linen. It got so hot that I got a burn on my finger when testing its temperature, but the linen underneath was not scorched. Why not? Maybe the dry heat from the slaking reaction is not sufficient to scorch. Maybe a little moisture or liquid water is needed in the linen as well, if, say, superheated steam were needed - or maybe some alkali too from the slaking reaction, i.e. calcium hydroxide. Maybe the thermochemistry needs to be a little more nuanced than I first imagined.  There's only a little quicklime left, and it takes 4 days or more for new stuff to be delivered, so there may be a hiatus. Correction: order placed, 2x1kg, express delivery (1-2 days).

Back to that 2015 Turin Shroud exhibition: I see it's open to the public from April 19 to June 24 (see flyer above). Do would-be viewers just turn up on spec, and join a long queue? Or is it by pre-booking only? What's the meaning of  "reserved viewing" in that escorted pilgrimage J'burg ad above? Is it really "reserved", or merely an appointed time slot for pre-booked parties, with no 'privileged access'.

Will I be attending? Nope, there seems little point in doing so if it means filing past a display case under glass, probably unable to view at close quarters.The only kind of visit that would make the trip worthwhile to this researcher is one where, in suitable protective clothing (naturally) I would be allowed to examine the linen and its image with a good hand lens under reasonable lighting with no intervening glass. Methinks that's unlikely to happen any time soon, if at all.

Today's experiment: I shall try thermochemical imprinting, with quicklime/water inside a hollow metal template, onto linen that is either (a) wetted with a little water (b) wetted with a little calcium hydroxide solution. Is the alkali  needed as well as heat for scorching in this geometry, while keeping the two in their separate compartments?

Update: Monday July 7

Fitted in between a feast of UK-based TV sport yesterday - Stage 1 of the Tour de France (well, Yorkshire actually), the British Grand Prix at Silverstone and the Wimbledon Mens' Final, I managed to fit a few of those experiments so confident of getting  a scorch imprint - and achieving - precisely zilch.

Despite the quicklime/water reaction generating sufficient heat to scorch linen in direct contact, it's not generating enough to scorch when enclosed in metal containers, separate from the linen. Why is that?

Pessimistically, I wonder if the temperature ever gets high enough to scorch indirectly.

There's a phenomenon that now (late in the day) springs to mind. One has to leave a metal template on an electric hot ring for 5 minutes or more to be sure of getting a contact scorch. When one lifts the same cooling template and scorches a second, third time etc one gets an instant vivid impression of just how much heat leaves the template at each imprinting, given the rapid loss of scorch intensity. But here's a salutary warning for the unwary. When the template fails to produce a scorch, and is then held under a tap, there's a loud sizzling sound and billows of steam. It is still very, very hot.

For some time, reading some negative comments about the scorch hypothesis, I've formed the impression that some imagine that linen is easy to scorch, so easy in fact that it can never produce a superficial image, that there must always be reverse side scorching (NOT SO!).

Wrong. It's quite hard to produce a scorch on linen: the template has to be really hot (probably at least 200 degrees C) and as I say, it quickly loses heat in each pressing, due to the overall conversion of linen carbohydrates to  yellow or brown pyrolysis products and steam - an endothermic (heat-abstracting) reaction.

I'm beginning to suspect that while my quicklime/water system can reach the required temperature, it fails to scorch linen through metal due to the heat capacity of the metal, i.e. absorbing and conducting heat not just towards but away from the target linen.

As I say, another 2kg of CaO is on order, so I shan't give up this otherwise promising line of enquiry just yet.

In fact, it may be that an alternative supply of heat could have been used in hollow cup-like templates of the sort proposed earlier, i.e. made by death mask casting techniques. Might the hollow have been filled with very hot oil, at the kind of temperature one uses to fry chips? Or if that didn't work, maybe molten tin, lead, or tin/lead alloy (solder) in a bronze casting?  All is not lost (and even if it is, there's always some face-saving patter ready and waiting in reserve).

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