Friday, April 25, 2014

How infuriating. LIRA (The Linen Industry Research Association of Belfast) is no more.

Yes, it closed in 1993. Damnation!

"The Linen Industry Research Association, Lambeg, Lisburn was a government research centre founded in 1921 for the study of textiles, especially linen. LIRA closed in 1993."


There's so much it could have done (if asked nicely) to check out the various Shroudie narratives (one in particular!) as to where the image is located on the Turin Shroud.

 Looks like I may have to invest in an upmarket microscope after all.

Binocular microscope? Is a binocular microscope essential  to check out the  claim (Raymond N. Rogers et al) that the image layer can be stripped off Shroud image fibres?  Would it be reproducible in superficial model contact scorches? How feasible is it to micromanipulate  individual scorched linen fibres under a standard microscope?

Further reading: here's a link to an extract from a book called "The King's Flax", which describes attempts, encouraged by the monarch (King George V) referred to in the title to put 20th century  UK flax and linen production onto a more scientific footing. It was that which led to the creation of LIRA. (This blogger has a soft spot for the UK's now dwindling number of industrial research associations, funded jointly by Government and industry, having worked for one, initially on Principal Scientific Officer grade in the  Nutrition and Toxicology Group for some 12 years, i.e. FMBRA - the Flour Milling and Baking Research Association).

Update: I see one can buy not only binocular microscopes but trinocular ones too, i.e. with both monocular and binocular modes of viewing. But do they come with a USB connection for viewing and screen grab, and low as well as high magnification? S  As reported earlier, the lowest magnification on my present USB microscope was too high in order to resolve a particular issue!

Some thorough catalogue-searching will need to be done in this household, with its attached kitchen-lab

Speaking of which, kitchen labs that is, I'm presently away from home (in Switzerland) and away from my usual kit. But I've been eye-balling what happens when one applies sticky tape to scorched linen. The first pull takes off heavily scorched fibres (not whole threads, note, but individual, so-called ultimate fibres). With fresh tape on the same area, one gets progressively lighter harvests of detatched fibres. So far so good. One is basically seeing what Raymond N.Rogers did with his sticky tape sampling of the Turin Shroud.

It's what happens next that is interesting. If one takes the sticky tape samples, one can lever up free or broken ends of fibres, and then pull them out with tweezers (tricky but feasible). When one looks at the extracted fibres, one's first thought is that they are colourless, matching Rogers' description, i.e. his claim that the image colour stays behind through being highly superficial and able to be easily stripped off. But here's the caveat. If one sticks the collected "clean" fibres back on paper with the same sticky tape. one then finds they are in fact still yellow or brown, and indeed is able to compare them with those that were not removed, i.e. still in situ, to see there is really no colour difference when compared side-by-side under the same conditions, i.e. white background, viewed through a thickness of sticky tape. In other words, one has to beware of artifacts when looking at individual fibres, even with the naked eye (with still more artifacts possible when using a microscope).

What I have described here is a means of viewing those stripped and unstripped fibres side by side, with the option of making a permanent photographic record. For the moment I for one shall be keeping an open mind as to whether the image layer of scorched linen is easily strippable and, by extension, whether that is true also for the Turin Shroud. As ever, where subtle colour changes and surface (?) phenomena  are concerned, the devil is in the detail. Thus the need to maintain a meticulous and objective photographic record.

Late update (Sunday 27 April). I see my posting, my very preliminary, some might say tendentious posting re the much quoted Rogers' sticky tape experiment, has quickly been picked up elsewhere.

It's illustrated with that amazing chequer board illusion that appeared on the same site over a year ago, and which this dyed-in-the-wool sceptic initially found hard to believe.

Well, here below is the initial claim, namely that squares A and B are both of the same grey intensity, followed by  my checking out using MS Paint to blot out the surrounding squares. Yes, squares A and B are the same intensity, incredible though that may seem, once isolated from their visual-cortex fooling surroundings.

Do squares A and B really have the same shade of grey?

Answer: YES!!!!!!!

Sunday, April 20, 2014

Ten good reasons for thinking that the Shroud image resides on an impurity layer, as proposed by explosives chemist Raymond N.Rogers

Sorry, but this retired science bod cannot think of a single good reason for thinking the Shroud image is on an impurity layer, whether it be starch, semi-degraded starch, soapwort, saponin, aloes, myrrh, whatever.

Nope. I'm not talking now about anecdotal evidence based on the supposition (at odds with the radiocarbon dating) that the Shroud is of 1st century AD provenance, when starch and/or natural soaps were allegedly used in spinning and weaving or bleaching.

I'm talking about hard chemical and other evidence, such as was acquired by the STURP team, to which the late Raymond N.Rogers was seconded as lead chemical investigator.

But you will not find Rogers' impurity coating thesis mentioned anywhere in the 1981 STURP summary of findings  - and rightly so in my opinion.

OK, so playing hunches has a vital role in science ("framing hypotheses") but they have to be (a) testable in principle if they are to be taken seriously and (b) tested in practice before they can be accepted into the mainstream of scientific thinking.

 Rogers' impurity coating idea not only lacks for hard experimental data, but the further development as his "Maillard reaction" hypothesis, proposing reaction between putrefaction amines(largely unspecified) and reducing  sugars (largely unspecified) appears to this sceptic as pie-in-the-sky.

More importantly, the idea has never been properly put to the test, unless one accepts at face value the results of a questionable experiment involving ammonia and a contrived mix of (conveniently) partially-degraded starch ("dextrins"), providing the needed "reducing sugars" that intact starch is lacking. The yellow colour, assumed to be a Maillard product (evidence?) is open to alternative interpretation, given the absence of required controls, e.g. on pH (recalling that ammonia is a base, as well as a nitrogen donor). The elevated temperature (66 degrees Celsius) used to obtain a reasonable rate of reaction (or thermodynamic feasibility?) does nothing to cement credulity if intended as a model for natural processes occurring in and around a fairly recently-deceased shroud-wrapped cadaver.

  Sorry,  I'm going to have to end here for want of hard scientific data. Sorry if the title misled. Sometimes the means do justify the ends- like deliberately derailing a  (now) driverless runaway locomotive before it's picked up too much speed.

Apologies in advance to those who think I have misjudged Raymond N.Rogers (RIP). Maybe I have overlooked crucial scientific evidence that  underpins his "impurity layer" hypothesis. If so, please feel free to comment.

In the meantime, this Shroud investigator will continue to regard the hemicelluloses of the primary cell wall (PCW) as the most likely target for the image-forming mechanism, and sees no need, absolutely no need, to assume that untreated linen, free of starch and/or other processing aids, modern or classical, is incapable of accepting an image onto its intrinsic PCW, e.g. via direct physical contact with a heated metal template.

Postscript: I see that Adler's observation that diimide, NH=NH, bleaches the Shroud image, is being adduced as evidence in support of Rogers' ideas. I fail to see why (being unmoved  by references to whether linen fibres look "clean" or "undamaged" before or after diimide treatment). What's the connection between events at the molecular level, and those at the gross one, with or without the benefit of a light microscope?

Second postscript:  It's been suggested  elsewhere that there is no way of telling whether the Shroud image is on the PCW or on a more superficial impurity coating. Admittedly that may be difficult using classical microscopy (atomic force microscopy is another matter). But it's not impossible using chemical means, though access to Shroud samples in the quantities required is as problematical as ever.

In fact I reminded folk last year of the technology that is available. It involves chemical hydrolysis of image v non-image areas via different graded acid-pretreatments, followed by  gas-liquid or HPLC separation of constituent starch and cell wall sugars. An image on the PCW  that resulted in partial or complete pyrolysis of the heat-sensitive hemicelluloses would be detected as a loss of hemicellulose markers (glucoxylans and other non-starch, non-cellulosic pentosan sugars etc) in the image-bearing samples relative to non-image controls. Alternatively, a putative image on a starch coating etc would be expected give the same profile of intact PCW sugars in image v non-image areas, with differences appearing in the additional complement of acquired starch etc, giving differences between the glucose recoveries.

Who says that scorch from a hot metal template onto linen cannot be superficial at the thread level?

Answer to question in title: the same individual who claimed that faint scorches cannot be enhanced, as per Turin Shroud image, with 3D image enhancement software (e.g. ImageJ, see previous posting). The claim is quite simply false?  How do I know?

I'm in Switzerland right now, away from home, away from my scorch kit, microscope etc. But I did bring some scorched linen with me, intending to tease it apart at leisure with needles to explore closely the depth of penetration of scorches into the bundles of fibres. Having just done that, using a pair of needles to extract single threads from the (quite heavily) scorched  areas of weave, and then using the same needles to tease apart those threads, I  can tell you this with absolute confidence, dear reader. That highly visible scorching is confined to just a few surface fibres (of which there are scores) in each linen thread. Put another way, it's a minority of fibres in scorched threads that are scorched. What's more, the naked eye alone is sufficient to arrive at that conclusion. One does not need a microscope to distinguish between scorched and unscorched fibres.

In fact, I suspect that it is uncritical examination of photomicrographs that has led to the wrong conclusion. It is all too easy to be fooled by in situ photographs . One has to tease the threads apart, separating individual fibres,  to be certain that patches of yellow colour really are there in cross-section, as distinct from being reflected or refracted light from surface scorched fibres.

Take away message: Scorches that are superficial at the fibre level can be superficial at the thread level too, and indeed are in my  linen specimens, even quite heavily scorched ones. Beware of claims to the contrary. Ask to see teased out fibres.

This is a holding reply needless to say. I'll try to give more details once I'm reunited with my experimental gear.

Colin Berry

Shores of Lake Geneva with splendid views across to French Alps

20th April 2014

Saturday, April 19, 2014

Who says that faint contact scorches (like the Turin Shroud's?) do not respond to 3D enhancement?

Here's one I did earlier in  ImageJ:

Click once or twice to enlarge

These were imprints from horse brasses obtained by serial stamping as the template cooled.

Note there is still 3D enhancement in the faintest of the 4 images.

What if there had not? (Would that mean that the Turin Shroud image cannot be a contact scorch?).

I would simply have increased the contrast first, to turn a faint image into a more intense one.. Cheating? Not at all. 3D enhancement is basically an empirical process where one adjusts a range of controls to achieve the best effect - 3D enhancement with minimal distortion. There is no law that says one cannot start by adjusting contrast to get the appropriate image intensity first, upon which to apply the 3D program (ImageJ).

The notion that faint scorches do not or cannot respond to 3D enhancement is a false one, and is certainly no basis upon which to dismiss the scorch hypothesis.

Further reading; See this posting of mine from 2012 entitled:   There is something rather special - and scientific - about this image of the man on the Turin Shroud.

I would commend the  experimental technique employed - which I called 'normalization' - to anyone minded to make comparisons between the Shroud image and model scorches, certainly where 3D enhancement is concenred.

Rather than just upload the 2D Shroud image into ImageJ, and twiddle controls to get the "best" result (what is "best" in a scientific sense?), I first produced scorch imprints off templates (horse brasses) and then used ImageJ to achieve the closest match between actual artefact and 3D-enhanced scorch image. Those same 'normalized' settings were then applied to the Shroud image - with what I considered (and still do) very satisfactory results, ones with greater scientific legitimacy.

Even so, one needs to be wary of comparisons between photographic images of Turin Shroud and model scorches. Quite apart from differences in the particular photographic methodologies employed, pre- or post digital, one has to be conscious that there may be age-related differences too that cannot readily be predicted, far less modelled.

Reminder: the definition of pseudoscience ( just one of several that could be quoted, this one taken from rationalwiki):

Pseudoscience is any belief system or methodology which tries to gain legitimacy by wearing the trappings of science, but fails to abide by the rigorous methodology and standards of evidence that demarcate true science. Although pseudoscience is designed to have the appearance of being scientific, it lacks any of the substance of science.
Promoters of pseudoscience often adopt the vocabulary of science, describing conjectures as theories or laws, often providing supposed evidence from observation, expert testimonials, or even developing what appear to be mathematical models of their ideas. However, in pseudoscience there is no real honest attempt to follow the scientific method, provide falsifiable predictions, or develop double blind experiments. Pseudoscientists often use the tactic of cheating the scientific method.

I particularly like the reference to conjectures that become elevated to the status of  laws. Beware especially the lawmakers of Shroudology,  especially those who peer down microscopes at their model scorches, and proceed to enunciate "laws" in their not-for-criticizing pdfs.

Wednesday, April 16, 2014

WeightWatchers bathroom scales come with misleading claims re their accuracy, even their precision..

Caveat: In what follows I shall be referring to kilograms  weight when, properly speaking, at least on a scientific site, it should of course be kilograms mass. Yes, this blogger is aware of the distinction between mass and weight. But the topic today is what in ordinary everyday life is referred to as one's body weight, changes in which we increasingly may wish to be aware of both precisely and accurately (more later on the difference between precision and accuracy). For any diehards who might be offended by my constant references to kilograms weight, then the advice is simple. Mentally substitute mass for weight OR if numerically inclined, multiply all kilogram figures by g, the acceleration due to Earth's gravity, whose approximate average value on Planet Earth is 9.8 metres/sec/sec, thus converting kilograms mass to the SI unit of force, measured in newtons, recalling that weight is a force.

So where does the WeightWatchers organization come in ( against whom I have no axe to grind except for a recent purchase of their bathroom scales that I now regret)?  Yes. I'm sure many folk have reason to be grateful to WW for their weight loss classes. Here's the object of my current aversion to WeightWatchers:

Sleek slimline WeightWatchers bathroom scales, with that digital readout.

They come with this booklet, clearly written by a Less Numerate. Less Scientifically-Aware member of their organization .

Title of the enclosed 'book of words' describes the supplied goods as a "precision scale"?  Really? Do the scales report the same answer on a series of repetitive weighings (regardless of whether the answer is accurate or not)?

"Precision" in the WeightWatchers dictionary would appear to refer to the readout, displaying weight to the nearest 0.1 kilogram. The calibration of the scale and readout has absolutely nothing to say regarding precision or accuracy, needless to say.  Indeed, a reading to the nearest 0.1kilogram conveys an entirely SPURIOUS degree of precision and accuracy, as is clear simply from reading the accompanying book of words. 

Again, it  claims it's a "precise" measuring instrument.  Really?  

It says it is accurate too (provided you stand still AND try to stand on the same area of the scales' platform). Can hedged-around "accurate" really be "accurate"? Oh, and it says not to "get on an off the scale repeatedly".  So how is one supposed to check the scales for precision, i.e. repeatability?

Deeper into the book of words we find this:

"Even a slight change in your position will cause a different reading"

Er, how can these scales be precise, never mind accurate, if a slight change in position gives different readings?  Weight is supposed to be directly proportional to mass, and directly proportional to gravitational attraction. It's not supposed to be affected by where one stands on a small platform. Nor is it supposed to be affected by the precise location of the scales on one's bathroom floor-covering (mine being vinyl plus underlay on top of concrete).

I guess it's that final sentence that is the give-away: This scale is designed for home use only and is not suitable for professional purposes".

So why the preamble that trumpets the scales' precision and accuracy? Do WeightWatchers know the difference between those two measures?

Scales that were inaccurate, but reasonably precise. might be tolerable, providing the inaccuracy were not excessive, say within 1% of the "right" answer, determined by some independent measure of greater intrinsic accuracy. Then one could take repetitive readings, hopefully not too dissimilar, and take, say, an average of 5.  But it's a waste of time doing that. The scales are NOT precise, and it's not difficult to see why, given that readings are affected not just by where one places the scales on one's bathroom floor, but where one stands on the platform.

So what was it that first alerted this science blogger to the lack of precision and accuracy in these scales (or this type of scales?).

Answer: it was first finding that dietary and exercise regimes that lasted a week were frequently failing to record loss of weight. Indeed, sometimes the answer could be as much as a kilogram greater than intital reading, which is dispiriting to say the least.

Note that I have been recording week-to-week changes, as advised in the book of words, so as not to be unrealistic re expectations.

The scales may be "valuable for monitoring your weight over months", but I question whether they are fit-for-purpose in measuring changes from one week to the next.

Just in case you had forgotten... "Your WeightWatchers scale is a precise measuring instrument..."

Oh no it's not!

"To ensure accurate readings, always try to stand on the same area of the scale platform, and DO NOT MOVE."

Well. I hate to be the bearer of bad news, WeightWatchers. but scales that give different answers depending on precisely where one stands. or which are highly sensitive to the slightest movement simply cannot be ACCURATE. And it goes without saying that they will not be PRECISE either.

It mightn't be so bad, except for the fact that scales for which I paid some £25 as I recall, influenced in no small measure by the WeightWatchers label were subsequently spotted elsewhere (or a near-identical looking model) at half the price. I have paid a hefty premium for the name. What a pity that WeightWatchers could not have been more forthcoming re the limitations of the product, both as regards the product name (dropping the term "precision) and those entirely misleading references to precision and accuracy in that book of words.

I have decided reluctantly to go back to my old scales.  OK, so it was difficult to read the scale despite the inbuilt glass lens, so one had to be content with knowing one's weight to within approximately the nearest kg or so. But that can spare one a lot of disappointment after a week or so of dietary restriction and exercise.

I would urge WeightWatchers to alter the display, either to give weight rounded up or down to the nearest kg, OR, if continuing to display to 0.1kg, to follow that with a  suitable and realistic +/- confidence range.Alternatively. tell one where one can buy 50kg calibrated masses, say, that one would place on the scales first, in order to determine if the scales are reading 'high' or 'low' on a particular day.

Conclusions. "WeightWatchers precision bathroom scales". No, something that cannot be relied upon to produce the same answer when one steps off, and then back on again, cannot be described as a precision instrument. Call it WeightWatchers Convenience bathroom scales, or WeightWatchers Handy Bathroom scales. Don't describe them as precision bathroom scales. It's doubtful whether any simple gadget that attempts to measure the force of the Earth's gravitational pull on an object, no matter how stationary the latter, especially of a live 'object' like a living breathing human being, can ever hope to be "precise". In fact, the WeightWatchers scales are imprecise - something that the accompanying book of words essentially acknowledges.

Afterthought: On a lighter note, maybe someone, somewhere, sometime will invent 'bathroom'(?) scales that genuinely display body mass in kilograms. Then none of the above gripes about  deficient mechanisms that measure mass as downward force on a dodgy platform would be necessary. Such a mass balance would be ideal in a world of interplanetary travel, or, come hyperdrive propulsion and warp speeds, interstellar travel to more inviting destinations too. So far we have CERN's LHC as a teaser. LHC = Large Hadron Collider. Hadrons are the massive particles - protons and neutrons - in the atomic nucleus that are responsible for most of atomic mass, and thus body mass too. So what's needed to determine body mass is an LHS - a Large Hadron Scanner. Sadly and realistically, the initial late 21st century (?) prototypes might tend to resemble CT scanners in hospitals. in which the human-to-be-scanned is slid on casters into a tunnel. So maybe it's too much to expect compact, space-efficient mass-measuring bathroom scales any time soon. Mass-measuring garage scales maybe, the latter cleared of all the other clutter like lawnmowers, hosepipes, algae-covered garden furniture  etc, maybe, just maybe.

Update 8th May 2014: have just this morning discovered the source of the SYSTEMATIC error on my bathroom scales. If one stands leaning slightly forward (as one does to read one's weight on the LCD), with one's weight mainly acting through the balls of the feet, one gets a reading that is typically 1kg more than if standing more upright, with weight mainly on the heels.

What's more, there's often a series of creaking sounds from the scales when one steps off. The error and the creaks are due no doubt to the weight being measured at 4 different points, i.e. the corner rubber feet on which the balance stands.

Whatever the mechanism, it is clearly UNFIT FOR PURPOSE, especially when it carries the name "Weight Watchers", where it may take at least a week (typically two on my gentle weight loss regime) to lose a single kilogram.

You have put your name to imported rubbish, Weight Watchers that probably costs next to nothing to mass-produce. Shame on you.

Update (intended for my previous lithium battery posting, but never mind): The BBC is in fact doing a series of features on the applications of the chemical elements and their compounds in everyday life. It's done in their "Magazine" rather than under a science/technology tab (interesting), and I see there have been previous ones in the series that I have missed (e.g. on aluminium) which I may return to at a later date. 

The reason for this update is that a new one has just appeared on chlorine ("From Toxic Chemical to Household Cleaner").

It's quite well done, but there's still a little confusion between sodium the element, comprising sodium atoms, and sodium in its compounds like common salt (sodium chloride), caustic soda (sodium hydroxide) etc where the sodium id present as the stable Na+ ion (a sodium atom stripped of its outermost electron).

Yes, the article begins by describing the heavy demands that the chlor-alkali process makes on electrical energy.  But it then attempts to illustrate that with reference to the electrolysis of (molten) sodium chloride, to produce metallic sodium (atoms) at the negative electrode and chlorine gas at the positive electrode. Note the complete absence of water (the system requires high temperatures at which sodium chloride is molten).  But that is not the is not the chlor-alkali process, which uses brine (a strong solution of common salt in water).The end product from the aqueous cell is not sodium metal (noting below the 'grey area' if it's an obsolescent Caster-Kellner cell producing sodium amalgam) but sodium hydroxide solution, along with hydrogen and chlorine gas. The sodium in sodium hydroxide is still Na+, so there has been no nett change in the state of the sodium (with a correspondingly smaller electrical energy requirement compared with the chlor-alkali process).

Overall reaction:

2NaCl  +   2H2O  =  2NaOH  +  H2  +  Cl2   (apologies for the = sign; arrow heads don't work)  

In ionic terms, the two half-reactions are as follows:

(1)      2H+  +  2 electrons at the negative cathode  =   H2

i.e. 2 hydrogen ions from 2 molecules of water are reduced by electrons to give a diatomic molecule of hydrogen gas.

(2)  2Cl-    = Cl2  +  2 electrons

i.e. 2 chloride ions are oxidised to a diatomic molecule of chlorine gas, returning the two  "borrowed" electrons from the electrical power source.

Geekish footnote:  However, some misunderstanding can be excused: the article makes brief reference to the old (19th century) process used in the chlor-alkali industry using mercury as the negatively-charged electrode (now largely abandoned due to environmental pollution by toxic mercury). In that so-called Castner-Kellner process, the sodium ions ARE discharged as sodium atoms into the mercury, where they form a liquid amalgam (with properties somewhat intermediate between those of an alloy mixture and inter-metallic compound(s) of sodium and mercury, NaxHgy etc). The amalgam is then run off and reacted with water to produce sodium hydroxide and hydrogen, so overall the process is the same as any other chlor-alkali electrolytic cell, with a form of elemental sodium ("protected" initially from water by its mercury keeper) being a temporary feature.

Further reading from "How Stuff Works": Inside a bathroom scale

The mechanical setup corresponds with what one was taught in elementary physics as that of a Class 3 lever, operating at what might be termed a mechanical disadvantage (example: tweezers). . The example given shows how a 112 kg mass is in fact measured at one tenth that figure (through having the fulcrum at a far end of the lever, the load (spring and pointer) at the opposite end, and the effort (the person's weight) acting close to the fulcrum.

Sunday, April 13, 2014

Beware BBC Business Editors who think they can write about science.

One of my perennial moans on this site is the hijacking of science reporting by media folk who think they can get their heads round science, but can't. The latest is Laurence Knight, Business Editor of the BBC, writing just two days ago on the use of lithium in rechargeable mobile phone batteries.

The title itself was an immediate giveaway. The lithium that is in the RECHARGEABLE cells of our lithium ION batteries does NOT power them. It's the electric current used for initial charging and subsequent recharging that powers them. The lithium supplies NO chemical and/or electrochemical energy to the uncharged cells. It's there purely a carrier and concentrator of externally-supplied electrical energy.

Pedantic? Maybe. But there's a common source of confusion about lithium in batteries, depending on whether the battery is PRIMARY (non-rechargeable) or SECONDARY (rechargeable).

One can and does have lithium metal, comprising lithium atoms, in a type of primary cell, and yes, it does take advantage of the exceptionally electropositive nature of lithium, the ELEMENT, which is the first member of the reactive alkali metals (though as the article points out, not as reactive as sodium or potassium in the same Group 1 of the Periodic Table).  But one would never be able to recharge a lithium primary cell once the metal had turned to a lithium salt (Li  to Li+ plus electron). It's simply not thermodynamically feasible to reverse that reaction under normal conditions of temperature etc..

The lithium ION battery works on an entirely different principle. It does not contain the reactive lithium metal, but lithium ions (chemically no more reactive than the sodium ions in one's table salt). It depends on a subtle effect, namely the penetration of lithium ions by the so-called intercalation effect in cleverly designed matrix materials.

Here's a handy image discovered on the internet:

So, unlike a lithium metal battery, which works without initial charging, the lithium ion battery will not work until it is given its priming charge, which causes those lithium ions to migrate from the positive electrode (left) to the negative electrode (right). Thus the introductory comment that it is not lithium that power this type of battery, but the electrical charge/recharge cycles. Lithium ions act merely as carriers of the externally-supplied electrical energy, albeit ones that can embed into the electrode materials for temporary storage.

So the lithium ion battery does NOT exploit the chemical reactivity of elemental  lithium, so references to the metal are irrelevant and misleading. What it does is to exploit the minute size of lithium ions (lithium comes 3rd in atomic number after hydrogen and helium in the Periodic Table, having just 3 protons and 4 neutrons).

Did Laurence Knight, Business Editor of the BBC, not bother to check his copy with the BBC's Science Editor before submitting for publication? I doubt it. In fact I wonder for how much longer the BBC will bother with a Science Editor when there are generalist liberal arts and finance-based journalists who consider themselves fully up to the task of reporting on scientific and technical matters.

Further reading? Try this for starters.


What is the difference between a “lithium metal battery” and a “lithium ion battery”?

A lithium metal battery (primary) is usually non-rechargeable, contains metallic lithium and features a higher energy density than other non-rechargeable batteries. Lithium metal batteries are often used in calculators, pacemakers, remote car locks and watches, to name a few.
A lithium ion battery (secondary) is rechargeable, does not contain metallic lithium and features high energy density. A lithium polymer battery is considered a type of lithium ion battery. Lithium ion batteries are used in consumer products such as cell phones, electric vehicles, laptop computers, power tools and tablets.


Postscript: internet search:

Laurence Knight's Education (in his own words)

University College London, U. of London

Master's degree, Eastern Europe stuff


University of Oxford

Bachelor's degree, PPE



So, in conclusion,  what might Laurence Knight have said that would accurately convey the flavour of lithium chemistry as applied to the batteries in everyday kit?  Flavour - ah now, there's a handy term.
Lithium comes in two flavours.  Mark 1 lithium atom-powered batteries - with a fiery flavour if you like. Open one of those up (not recommended) and you'll find a metal there so chemically-reactive that it froths when you add water, liberating flammable hydrogen gas. Those batteries have a limited application - since they are not rechargeable,.
What we have in our mobile phones is tamed lithium - lithium ions, which are atoms stripped of a single electron. Think of it as Mark 2 vanilla-flavour lithium.Lithium ions are lithium atoms that have lost their oomph. But they can still be made to serve as workhorses. Sorry about the mixed metaphors.

Tuesday, April 8, 2014

"There is no possibility whatsoever that the image on the Shroud is a scorch. . . ....". Who says? Ask to see the experimental evidence - and check scientific credentials.

 Who else recalls that celebrated self-mocking (1973) roadside ad for Guinness stout ale:

Guinness ad: "I've never tried it because I don't like it

(It took quite a while  to track down an image of that memorable ad on internet  files. Methinks Guinness may have had second thoughts about its ability to attract new custom!)

I was reminded of it when reading the latest posting on, to give it a polite appellation on this bright sunny morning in the UK, now the Saharan smog and rain have passed over (see previous posting).

Yes, how many times have we seen those words in my title, quoted by shroud-authenticity promoters, the latest being from a gent with a leading role in the post-STURP, cat-that-got-the-cream $TERA. That's the "$hroud of Turin Education and Research Association" ho ho ho in case you didn't know. Sounds of cash registers ringing...

I've lost count of the number of big cheeses in the Shroudie Land who have solemnly incanted those words. Yet the vast majority have never bothered to produce a single contact scorch. I have - hundreds of them. While I sadly lack the technology to prove it, I invite others to disprove my contention that a contact scorch on linen can be as superficial as one likes, right down to the molecular scale at surface (primary cell wall) level. I see no theoretical or practical objections whatsoever

(ed: I've been taken to task elsewhere for that "prove me wrong" challenge. I've been accused of the very thing I condemn on this site (pseudoscience). Methinks the gent concerned should acquaint himself with the history and practice of science before attaching the p word to a published scientist, albeit long retired. He could do a lot worse than read up on the Higgs boson, whose existence was first predicted  by Peter Higgs in 1964, but it was needed as a vital component of the Standard Model (explaining why subatomic particles have extraordinary mass over and above relativistic mass that is predicted by e = mc squared). Higgs did not have the technology to prove the existence of his particles, nor did anyone else, until CERN's LHC proved its existence in 2012. Nobody condemned Higgs or anyone else for assuming the particle was there, if only to maintain the most all-embracing Theory of Nearly Everything. (except Gravity Dammit). Indeed, Higgs was awarded a Nobel Prize last year, despite having no hand in the experimental confirmation.  Homo interneticus, bereft of any formal scientific qualifications or research experience,   likes to think he understands the scientific method, but in my experience rarely appreciates the respect accorded to hypotheses and theories that unite a lot of existing disparate observations, but which still await the kind of experimental data that banishes most lingering doubts held by (fair-minded) sceptics. I exclude the flat-earth tendency from that final description, like those who think the radiocarbon dating MUST be wrong because it conflicts with their dossiers of "historical" and other evidence. It never seems to occur to them that the radiocarbon data conflicts with their self-serving agenda-driven quest for "spy clues" to the existence of the TS pre-14th century. Some of those spy clues, like tiny ink-drawn circles on an otherwise obscure Hungarian codex being evidence the illustrator  was signalling he had seen the Shroud  with his own eyes are frankly risible, indeed, faintly ludicrous, but to many in Shroudie  Land they constitute incontrovertible evidence against a 14th century provenance, and woebetide anyone who suggests otherwise. No, I'm not and never will be a Peter Higgs, with a 360 degree view of his chosen area of research. Mine's more like the standard 45 degrees. But I'm not a pseudoscientist either, like so many others I could mention who have dabbled in Shroudology, playing to the same old gallery).

So to STERA promoters and others: kindly cease recycling the same old mantra that the Shroud image cannot be a scorch. STURP never said that, as many folk seem to imagine. Read the STURP summary in full* and a reasonable person, free from preconceptions, religious or otherwise, might conclude precisely the opposite, namely that an image created by pyrolysis of linen, i.e. thermal degradation alone, is FULLY CONSISTENT with contact scorching. Elsewhere, in the course of some 200 and more postings,  I have addressed the many previous attempts to dismiss that notion, but they were either lacking in experimental support, or, one one occasion, accompanied by a risible and hamfisted demonstration of how to over-scorch.

Oh, and let's not forget the occasion when the $TERA top man no less deployed the nuclear option : ... there is no possibility whatsoever that the image on the Shroud is a scorch because ...   drum roll ..  it fails to show obligatory fluorescence under ultraviolet light. Yeah, right...Thanks for the chemistry lesson. Sadly I missed out on the photography module at University, having to do tedious and irrelevant stuff like 2 years of subsidiary organic chemistry. Uv fluorescence is a property of certain specific molecules. Those molecules are not necessarily permanent fixtures. They can oxidise, polymerise, volatilize etc. Lack of fluoresence, centuries after formation, proves nothing, ABSOLUTELY NOTHING., except maybe to photographers-turned-organic chemists and/or other $hroudie-circus showmen.

Postscript: here's a link to a posting I did over 6 months ago -  admittedly not my finest hour re concise reporting of new experimental findings - that I suspect gives the strongest clue as to why fabrics like linen and cotton (cotton especially) can take a scorch-imprint without falling apart.
Basically, what I found was that cotton can be scorched more easily than linen at any given temperature, but that the difference is reduced by pre-treatment of the fabric with strong alkali.

I interpret that as cotton having a greater concentration of fragile (thermolabile) non-cellulosic polysaccharides in the outermost primary cell wall, due either to genetic differences, OR the fact that cotton requires no retting to separate fibres, and that alkali targets those fragile polysaccharides (hemicelluloses etc) leaving cellulose largely intact, at least chemically. That leaves less target-material ON THE SURFACE for imprinting an image.  The underlying cellulose (especially the highly crystalline inert  variety in the core of the fibre, representing the secondary cell wall) seems to be largely irrelevant where contact scorching is concerned, at least where imprinting of a highly superficial image is concerned - one that attempts to model the faint image on the Shroud.

Here's a graphic from that posting, showing how alkali-treated cotton gives a less intense scorch than control(untreated cotton).

The difference seems to be greatest in the second-from-left imprint where the template was still very hot and held longer against the fabric, before 'serially imprinting' while progressively cooling (images to the right). That's suggestive of there being more than one chemical species qualifying as 'more thermolabile than cellulose'. There's a largely unexplored world where knowledge of contact scorching is concerned,  one this kitchen-experimenter can only hint at.  Who would know or even suspect it -  looking all those categorical and dismissive comments made in Shroudie Land, like the one in the title.

When in doubt - experiment. It's the sure way to experience the buzz of real science - as distinct from received wisdom/dogma, all-too-often pseudoscience.  Not for nothing is this site called "sciencebuzz".  As the song goes: "It ain't necessarily so..."

*A Summary of STURP's Conclusions

Editor's Note: After years of exhaustive study and evaluation of the data, STURP issued its Final Report in 1981. The following official summary of their conclusions was distributed at the press conference held after their final meeting in October 1981:

No pigments, paints, dyes or stains have been found on the fibrils. X-ray, fluorescence and microchemistry on the fibrils preclude the possibility of paint being used as a method for creating the image. Ultra Violet and infrared evaluation confirm these studies. Computer image enhancement and analysis by a device known as a VP-8 image analyzer show that the image has unique, three-dimensional information encoded in it. Microchemical evaluation has indicated no evidence of any spices, oils, or any biochemicals known to be produced by the body in life or in death. It is clear that there has been a direct contact of the Shroud with a body, which explains certain features such as scourge marks, as well as the blood. However, while this type of contact might explain some of the features of the torso, it is totally incapable of explaining the image of the face with the high resolution that has been amply demonstrated by photography.
The basic problem from a scientific point of view is that some explanations which might be tenable from a chemical point of view, are precluded by physics. Contrariwise, certain physical explanations which may be attractive are completely precluded by the chemistry. For an adequate explanation for the image of the Shroud, one must have an explanation which is scientifically sound, from a physical, chemical, biological and medical viewpoint. At the present, this type of solution does not appear to be obtainable by the best efforts of the members of the Shroud Team. Furthermore, experiments in physics and chemistry with old linen have failed to reproduce adequately the phenomenon presented by the Shroud of Turin. The scientific consensus is that the image was produced by something which resulted in oxidation, dehydration and conjugation of the polysaccharide structure of the microfibrils of the linen itself. Such changes can be duplicated in the laboratory by certain chemical and physical processes. A similar type of change in linen can be obtained by sulfuric acid or heat. However, there are no chemical or physical methods known which can account for the totality of the image, nor can any combination of physical, chemical, biological or medical circumstances explain the image adequately.
Thus, the answer to the question of how the image was produced or what produced the image remains, now, as it has in the past, a mystery.
We can conclude for now that the Shroud image is that of a real human form of a scourged, crucified man. It is not the product of an artist. The blood stains are composed of hemoglobin and also give a positive test for serum albumin. The image is an ongoing mystery and until further chemical studies are made, perhaps by this group of scientists, or perhaps by some scientists in the future, the problem remains unsolved.
Brief summary/update of my own position re the scorch hypothesis after some 2 years/200+ postings.

1. At the outset I could see scarcely if any scientific merit in non-contact scorch hypotheses, notably those involving radiation or of putrefaction products leaving a chemical imprint. But then advocates of those hypotheses seem content to assume them correct, while failing to seek and provide experimental confirmation. In short, those ideas are nor scientific, and it is thus pseudoscience to maintain that they are.

2. I initially envisaged the scorch technique as one of heating a metal template, probably bas relief, and pressing it down into linen spread out of a yielding material, e.g. bed of sand. But there were difficulties with that, notably that one could not easily monitor the progress of scorching, thereby risking over-scorching. There might also be excessive tenting of the linen between extremities, say between the kneesand the tips of the toes, with minimal imprinting of everything in-between,

3. When experimenting with a brass crucifix as template, I reversed the geometry, laying the heated template down on a hard surface, covering with linen, then, quickly, with a damp overlay, and manually moulding the two apposed fabric layers to the major surface contours. That procedure, which I call the LOTTO method (Linen On Top, Then Overlay) allows one to monitor heat flow (touchy-feely technology!), makes it harder to over-scorch (in fact, near impossible), gives a fuzzier, arguably more Shroud-like image,  and seemed the right answer if one were aiming to develop the TS image in a single step.

4. However, the LOTTO method does not account for some alleged subtleties in the TS image at the microscopic level. While one has to take much on trust - much that is written being little more than anecdotal - one might with the eye of faith describe the TS image as showing a half tone effect, where apparent differences in image intensity are not due to continuously varying scorch intensities between neighbouring fibres, but to differences in a chosen area between numbers of fibres that are scorched to a particular maximum level OR unscorched, with no in-in betweens. The half-tone effect could be described as digital as distinct from analogue imprinting. Some might consider chemical precedents for "digital imprinting" are few and far between, encouraging one to seek explanations that involve two or more steps, rather than a single one.
Recently I have proposed just such a two step mechanism involving: 1. Intense analogue scorchimg as a primary step, i.e. at point of manufacture centuries ago. 2. Subsequent loss of all scorched fibres, except those that are minimally scorched, e.g. by selective pyrolysis of the outermost PCWs, that does not impair the mechanical strength of the whole fibre. The half-tone effect then gradually appears via a 'survival-of- the-fittest' process leaving finally just two (main) classes of fibre - minimally-scorched versus unscorched.
The transition from intense to fainter scorch could have been entirely natural and unaided, Alternatively, it may have been accelerated at some point early on, in order to 're-invent' a deliberately-contrived scorched image, representing say, a martyred Templar, as one of the crucified Jesus, with a fainter attenuated scorch being promoted as a Veronica-like sweat imprint.  See the more recent postings on my now dormant specialist Shroud blog for more details on the "reinvention" hypothesis.

5. As hinted at earlier (but still little more than conjecture so far) I'm toying with the idea that that the LOTTO method was used, and, at least for the torso, might have used a 3D bronze that was half-embedded in sand to make it effectively a bas relief at the imprinting stage. What's more, the sand bed itself could be hot (used in fact to heat the template) relying on the fact that contact between linen and sand, far from being undesirable, might help to provide an instant  aged yellow look to the Shroud linen, with a smaller contrast difference between image and background for your more authentic-looking Shroud .

Initially I considered  that a bronze of the crucified Jesus might have been chosen, even if intending the image to be promoted, at least initially, as that of a more modern martyr, notably a Templar (Jacques de Molay?), the chemically pyrolytic/artistically pyrographic art form signalling the manner of execution (slow roasting at the stake). Another possibility has since occurred to me. Were there life-sized bronzes available in medieval times of St.Lawrence of Rome, who also was put to death by slow-roasting (258AD), with much medieval art work (painting) depicting him horizontally on his grid iron, often held  down by men with tridents or pitchforks, with or without cords?

Artist and date still unknown to this blogger, despite the above picture of St.Lawrence appearing in many different internet sites.

The advantage of using an effigy of St.Lawrence, if available, is that hands may have been in the right location to start with, if the contemporaneous 2D representation in art were anything to go by.

Reactive postscript:

Message to the gent on Troll Central. aka shredstory.som, who is trying to stick the charge of pseudoscience on this pro-scorch, anti-authenticity investigator.

You’re wrong, just plain wrong, indeed about so many things.

You’re  one of these people who imagines that science demands instant experimental confirmation of a new idea, that nothing can proceed without that confirmation, and that there’s an obligation on the originator of an idea to deliver the confirmation, or otherwise keep his thoughts to himself. At least, that’s your position where this investigator is concerned, though I note you do not demand the same of those who are content to sketch out airy-fairy scenarios of mysterious bursts of radiation,  or of ammoniacal vapours that travel in straight lines to conjectural sugary targets in linen.

Sorry, all you and other like-minded 'more-scientific-than-thou' armchair philosophers. That’s not how science works, and never has been.

 Science is primarily about ideas. Ideas run in advance of experimental corroboration, sometimes by years, decades even.  It’s the ideas, shared freely soon after inception  that provide the buzz for many in science.  There’s as much interest in supporting or refuting other people’s ideas as there in one’s own. It’s a collegiate thing: ideas go into a common pool. They may be known by their originator’s name, as a courtesy, and less charitably, to prevent plagiarising by those with no ideas of their own. But once an idea is out in the open, the genie’s out of the bottle, and there’s a sense in which it then belongs to science, rather than its originator. There is no shame in having one’s idea proved (or even disproved) by another scientist, the essential test of its scientific merit being whether it shows predictive utility, and whether or not it stimulates new lines of investigation, hopefully productive, that might otherwise not have been tried.

It’s time the world of shroudology ceased pretending that the scorch hypothesis was ruled out of contention  by the tendentious lines of argument advanced by Raymond N.Rogers and others, least of all by STURP (see previous posting).  It was not. While wishing no disrespect to someone who has sadly passed on, Rogers seemed to regard linen fibres as if they were composed entirely of cellulose. He made scarcely any reference to the chemically more reactive non-crystalline matrix of hemicelluloses, except as an “impurity”. Neither did he make reference to the superficial PCW (primary cell wall) that I can recall. Indeed he seemed to have no knowledge or even interest in the nature of the linen fibre as a botanical entity. To him, it was simply cellulose fibres, scarcely any different from his chemist’s filter paper.

  Those who have survived him have even less excuse to ignore the likely role of PCW hemicelluloses in scorching, given it’s now over 2 years since I posted a reference to Yang et al, emphasising that hemicelluloses pyrolyse  in a much lower temperature range than cellulose.

“…the pyrolysis of hemicellulose and cellulose occurred quickly, with the weight loss of hemicellulose mainly happened at 220–315 °C and that of cellulose at 315–400 °C….

 As I say, absolutely no excuse.  The facts speak for themselves. One cannot turn a blind eye to the facts. One cannot claim to be investigating the Shroud image scientifically, making vague references to some kind of “radiation”, usually unspecified, and failing to recognize the existence of the superficial PCW with one or more components prone to contact scorching.  Scorching by direct contact (zero air gap)  explains so much (the negative image especially, its preferential location on crown threads, its chemical and spectral  properties  which though poorly characterised thus far are consistent with pyrolysed, i.e. thermally-degraded carbohydrates, with no direct evidence that I’m aware of that it might represent a non-enzymatic browning product due to Maillard reactions requiring  an exogenous source of amino- nitrogen AND reducing sugars.

It’s time the world of Shroudology woke up and smelt the coffee. It’s the roasting of coffee beans that gives them their aroma. It was almost certainly the roasting , or rather scorching of linen carbohydrates due to direct contact with a heated  object that gave them their physical and chemical fingerprint, albeit presently lacking in detail and a facsimile negative image.

 (But why is that? I’ll tell you why. It’s due to wilful and chronic neglect following a  premature rejection  of a commonsensical proposition – thanks in no small part to what can only be described as agenda-driven pseudoscience, of refusing to give proper consideration to a particular IDEA). 

Which is where we came in. Science is the world of ideas. Ideas have to be addressed fairly and squarely - not swept under the carpet- citing anti-idea arguments that lacked credibility, to say nothing of objectivity, right from the word go.
Update: 22:30 Wed 9 April

April 9, 2014 at 4:26 pm | #5
CB: ” Yet the vast majority have never bothered to produce a single contact scorch. I have – hundreds of them. While I sadly lack the technology to prove it, I invite others to disprove my contention that a contact scorch on linen can be as superficial as one likes, right down to the molecular scale at surface (primary cell wall) level. ”
Colin, you have “hundreds of them”..
Me too.
You have a microscope. You could easily demonstrate that a ” a contact scorch on linen can be as superficial on linen as on likes..”
At least at thread level.


Back in November last year, I tried deliberately, with no success, to ‘over-scorch’ using my LOTTO procedure.The best I could do was to produce faint scorches on linen that might reasonably be described as Shroud –like on that basis. But expecting me to show that those scorches are highly superficial at the thread level, which may sound reasonable to the uninitiated,  is not as simple as it may seem. 

Why not? Because scorches that are exceedingly faint at the macroscopic level become almost impossible to detect when viewing individual threads or fibres under the microscopic. One is in effect asking the impossible – at least where a kitchen lab is concerned -  to produce faint scorches that can then be studied at the microscopic level. 

Don’t believe me? Then check the several photomicrographs in the posting linked to above. It becomes virtually impossible to distinguish between individual coloured and uncoloured fibres under the microscope, which is what one has to do in order to determine superficiality even at gross thread level. The colour one sees, such as it is, the merest hints of yellow or brown coloration, comes from seeing bundles of fibres packed closely together. It is asking too much to expect one to categorise individual fibres by colour, say by probing with a needle. A subtle scarcely visible scorch is just that – a subtle scarcely visible scorch.

Put another way: if one is asked to produce scorches that are highly superficial at the macroscopic level, judged on the basis of faintness to to the unaided eye, it is unreasonable to ask for visual proof of superficiality at the microscopic level.  The human eye is a wonderful thing - but cannot be expected to perform miracles. The better the model in terms of faint image, the progressively harder the model becomes to probe microscopically.

All of this needless to say distracts from the real issue, namely that it is ultimately against the spirit of science to attempt to dismiss or even marginalize scorching by contact, when the facts speak for themselves: contact scorching accounts for the major characteristics of the Shroud image. 

Where there are gaps or discrepancies, the first thought should be to account for  them in terms of precise scorching technique - LOTTO etc- or maybe secondary ageing effects. It is hardly scientific to nitpick or snipe at a model that explains so much, when there are no other credible models on offer, at least not ones that fulfil elementary scientific criteria  of theoretical feasibility and experimental testability..

Ray Rogers - along with several others - attempted to strangle the scorch hypothesis at birth.  But the case for immediate euthanasia was full of holes, as I have repeatedly pointed out. It was hardly one of the more glorious chapters in the history of science.

But the baby somehow survived, and is now a rebellious and unruly teenager, riding around on a noisy motorbike.

The successors of Ray Rogers, kindred spirits in detesting any idea of a medieval provenance, never mind scorching, are now attempting to set up road blocks, or, as in the cartoons, to paint what could be mistaken for dark tunnel entrances onto roadside outcrops of solid rock.

Thursday, April 3, 2014

Some thoughts on the Sahara dust, aka "smog", aka "pollution"

From today's BBC website - the so-called "smog".

Once again, the UK media is fouling up spectacularly, through conflating numerous factors that need to be separated.

Yes, there is Sahara dust settling on our cars after rain. The phenomenon has been known at least since the reports of Darwin, sailing across the Atlantic.  And yes, airborne dust may irritate the airways or lungs of susceptible people, those with pre-existing conditions especially, but keeping children at home instead of school is a massive over-reaction. Who created an instant scare and why?

If it is Saharan dust alone, then all I can say is "get real". I was in the savannah north of Ghana in the late 60s when visibility was down to a mile or less, thanks to the Harmattan (fine dust blown in from the Sahara).

Ghana during the Harmattan season  (Akosombo dam).

But I never coughed, and don't recall others doing so. The main concern was cracked skin on lips, due to the dry air.

So are there other nasty ingredients in the mix, responsible for the "smog" description?  Is it photochemical smog? Maybe, that's easy enough to check, since the chief particulate there is  likely to be miniature suspended crystals of ammonium nitrate or sulphate. Have we been given data for grown ups? Nope. We're talking about the UK media here with its exceptional inertia and resistance to getting on to experts in universities, the learned societies and elsewhere who know about such things.

Maybe it's plain old diesel engine pollution, giving rise to excessive levels of nitrogen oxides or small carbon particulates (PM10s). Any hard evidence for that? Nope. We're talking about the UK media here. Don't bother asking for hard evidence.

More later, once we have some data, some numbers that might justify the current headlines that would have us believe that the air we breathe is essentially no different from that of Beijing's.

See this blogger's previous posting on Saharan dust, photographed while on holiday in Pisa, with some speculation re a possible role in spreading foot-and-mouth disease. (OK, a bit of a long shot).

Update:  Telegraph:  Saharan dust and pollution. We need a sense of proportion says Boris Johnson.

And here's a link to a video clip on the BBC's site, an interview with a senior ' air quality analyst" talking about "pollution" without specifying its nature, except to say it's "sometimes" washed out of air by rain, but not always, because, wait for it, "it's a bit complicated".

To think that I and most of my fellow countrymen and women pay a hefty annual licence fee for that condescension, that banality!

What was interesting was to hear that London is now at the top of our local 10 point scale for "pollution" (whatever that means). But don't run away with the idea that we now match Beijing, where the top of its scale is described  as "100 times higher".  The issue-obscuring, dare one say media smog  gets  progressively worse, progressively dumbed-down,  year on year.

Update: Friday 4th April

Today I'll be attempting to dissociate the various conrtibutions  to what our media are presently describing as a 'killer smog'. A few more perceptive outlets are referring to a "cocktail" though for many "dog's dinner: might be a more appropriate description.

We'll start by conidering the origin of the term smog as a mixture of smoke and fog, and why it came to such prominence in connection with the London 'peasoupers' in the 1950s, which this blogger recalls vividly (one could stretch one's arm in front of one and be unable to see one's finger - but were still expected to find one;s way to infant and junior school). We'll look at the meaning of smoke, in a scientific context, as an aerosol of suspended solid particles in air or gas generally, and ask if it was really "smoke" that was killing thousands of people when raw coal provided the chief ,means of heating homes, until the Clean Air Acts arrived, requiring first smokeless fuel, and then gradually encouraging cleaner alternatives to solid fuel, notably gas and electricity.

We'll then look at 'photochemical smog' associated with vehicle pollution, and of great concern in US cities especially in the 60s and 70s, and consider the nature of vehicle exhaust emissions, before and after the introduction of now obligatory catalytic converters, and the crucial role that sunlight plays (thus the 'photo' of 'photochemical'). We'll find ourselves discussing ozone (that's ground-level ozone, one of the nastiest and most insidious of the air pollutants), and how it comes to accompany photochemical smogs,  but also ask what the solid components are of a photochemical smog (since ozone, nitrogen oxides, sulphur oxides, unburnt hydrocarbons etc are gases and/or vapours, not solids).

Finally, we'll briefly consider the difference (if any) between a smoke and a dust-laden atmosphere.

The Great Smog of 1952

Here's a link to essential background reading (and very readable too):component of the smog that brought visibility down to feet and sometines inches.

I shan't try  to summarise it here. Suffice it to say that what descended and got trapped over London would have been  "smog" literally, i.e. a combination of fog (minute swirling airborne droplets of condensed water vapour) and solid particles, The latter, the suspended solid "smoke" component was derived from the burning of soft coal prior to replacement with smokeless solid fuel (coke, anthracite etc) . (Light porous coke is coal that has had volatiles driven off first, so that it produces fewer gases and vapours,  little if any flame, and much less sending aloft of solid carbon and ash particles). That's the visual aspect. But it's unlikely that smog as described here was the real killer. The latter was almost certainly due to the "passengers" in that smog, notably oxides of sulphur (SO2, SO3, i.e. sulphur dioxide and trioxide) and especially droplets of sulphuric acid, H2SO4, which form when oxides of sulphut react chemically with moist air.

So while the killer smogs of the coal-burning era are of limited relevance in modern UK, Europe and the US (though still a major contibutor in China) they provide a pointer as to the multifactorial nature of man-made air pollution. There is visual pollution one can see - suspended solids especially. But there are the less visible or indeed invisible components that one cannot - noxious gases and liquid acids derived therefrom.

Is the present smog over the UK a killer,or potential killer? Are the mortuaries filling up with old people especially who have wheezed and coughed to a premature grave, as was the case in 1952, when there was suddenly a shortage of coffins, and when florists shelves were cleared of flowers?

The answer so far seems to be NO. In fact, the London Ambulance service reckoned there were an extra 27 call-outs for the entire city that could be attributed to the "killer" smog.  That is reassuring, while no grounds for complacency. Let's press on all the same with the science, and ask whether the poor visibility and air pollution readings really justify the term "smog" or whether dust-laden wind from the south, with additional vehicle pollutants from the Continent, with or without appreciable photochemical endproducts, are the cause of the hundreds of scare stories in our media.

Here's a link to the latest from the BBC's website. I recommend careful reading.
What seems increasingly clear is that our EU masters are using the visibility of this pollution episiode, due to an entirely natural phenomenon, in ordre to justify ongoing legal action against the UK for excessive levels of nitrogen oxides.

But the main cause of nitrogen oxide pollution is diesel engines , which previously have been promoted for their greater fuel economy on a mile per gallon/kilometre per litre basis.  Catalytic converters are supposed to deal with the greater amounts of nitrogen oxides, formed primarily by reaction between atmospheric nitrogen and oxygen under higher compression/temperature compared with a petrol engine - but which clearly do not. It's hard to escape the thought that the EU are being incredibly opportunist right now, and need to step back and think through the science, pollutant by pollutant, source by source. Our control freak masters in Brussels also need to bear in mind  that air pollution, especially from vehicles and industry, is no respecter of national boundaries.

Photochemical smog

Here's a good link that explains the complexity of photochemical smog. 

Why is it good? First, it focuses attention on end-product ozone, O3. a very nasty airways irritant. Secondly it shows how those nitrogen oxides, undesirable in themselves, operate as recycling catalysts to cause oxygen conversion to ozone. Thirdly it shows the permissive role that is played by petrol fumes released into air when you fill up your car, the socalled VOC component of air pollution (VOC = volatile organic compound) which through complex chemical cycles results in far more end-product ozone than would otherwise be the case.

Update: Friday 10:30  Comment under the Boris Johnson article in the Telegraph:

I cycled 15 miles on Wednesday, 35 miles yesterday. It was only when a friend berated me for 'not heeding the warnings' that I even knew we supposedly had a 'pollution' problem. Though the air had seemed a little hazy, there were no other noticeable effects
I'm in my late 50s and line in the South-East - supposedly the epicentre of the disaster
But I do recall a similar incident of Saharan dust back in the 60s. The major worry then was not about people's health, but about the need to redo the washing which was hanging on the line.

Update: Middle England:
the day started very overcast and gloomy, and my first thought was: Are the Jeremiahs maybe right after all? Is there an exceptional weather event, bringing exceptional air pollution?Well, it's now mid-morning. It's still gloomy but there is no problem as regards visibility. The wooded ridge, about a mile away, that I see from my window is in plain view with no hint of haze in the air. It's simply overcast with grey skies, and children are playing happily outdoors in the nearby school. Next apocalyptic crisis please, dear UK media.

 I shall now take a break, needed to go through 44 pages of  the EU's pdf setting out limits on common air pollutants (oxides of sulphur, nitrogen, fine particulates etc). Not surprisingly, ozone limits are not specified, it being assumed that limits on the primary precursors (nitrogen oxides especially) should prevent excessive O3 production.

Update: 5th April. The story has now died the death, glad to say. Once again, the way this story broke did not reflect terribly well on our print media, especially the tabloid end with its "killer" smog headlines (but what else is new?). I still have to track down (if possible) the actual data that got the Government claiming there was a conjunction of both Sahara dust and top-end levels of normal pollutants (yes, I'm sticking with this topic for a while longer, if only to be better prepared to respond to the next alert tha keeps children off school, probably needlessly). I had a sudden thought last night. That 10 point scale the Govt use is made up of different pollutant concentrations (SO2, NOx, and, wait for it, particulates, especially the smallest particles - PM 2.5 and PM10s): the latter are often, dare I say usually taken to mean fine carbon particles, especially from diesel engines. You don't suppose that Saharan dust particles upped the PM figures, and that the assumption was made that any fine particle, capable in theory of being trapped in the lungs, was as bad as another? Evidence? To return to my earlier point, what is the evidence if any that people who live in the savannah regions bordering the Sahara desert, who have an annual harmattan season with poor visibility, suffer an appreciably higher rate of airway and lung disorders than those who live elsewhere?

Update: Sunday 6th April. Spotted that the Sunday Times had done a front page feature on diesel fumes this morning, and not having an online subscription, went out to buy the dead tree version (first time I've done that in year).
In fact there are three items in today's  paper no less, all focusing on what is seen as the grozing menace of diesel engine pollution, prompted, rightly or wrongly, by the Saharan dust.
As I say,the first is on Page 1 and 2, entitled: "Diesel deadlier than petrol". The second is on Page 11: "Diesel fumes hard children's brains" and then there's the much-respected Camilla Cavendish on Page 23: "With every extra breath, children demand we are weaned off diesel".There are some alarming statistics in those three articles about the growing levels of atmospheric nitrogen dioxide and fine particulates that have been linked  diesel-powered commercial vehicles AND especially to the growing popularity of diesel-engined cars. I'll be back later with some details. Suffice it to say that modern research indicated that those fine particulates are not just a threat to lung function. They transported to all parts of the body - heart and brain included -  and are now implicated in a much wider range of pathology than previously (strokes, heart attacks, age-related memory loss, even autism). Living as I do less than a mile from one of England's major motorways, and (subjectively) aware that I cough a lot more than I did before moving here, I shall be keeping a closer watch on air pollution issues from now on, reporting anything that appears noteworthy, or areas of possible miunderstanding in the media.Update: 1st May 2014: articles in Daily Mail: "The Deadly Diesel Deception"