Make choo choo go faster

Captain Matthew Henry Phineas Riall Sankey sighed and shaded his tired eyes from the bright glare of the oil lamp. Its light reflected harshly from the jumbled mounds of papers that entirely covered the dark oak surface of his desk. He took a moment to roll down the wick and dim the light. The chaos of his work area hinted at the chaos currently roiling in his usually precise and meticulous engineer’s mind.

He leaned backward in his chair, his shoulders slumped in despair. This problem had defeated many other men before him, he reflected as he stroked his luxuriant moustache: there would be no shame in admitting defeat.

After all, he was only one man and he was attempting to face down the single most serious and most pressing scientific and engineering issue known to the world in the Victorian Era. And yet — he couldn’t help but feel that he was, somehow, close to solving it. The answer seemed to hover mirage-like in front of him, almost within his grasp but blurred and indistinct. It became as insubstantial as mist each time he reached for it. He needed a fresh perspective, a new way of looking simultaneously both at the whole and at the parts of the question. It was not so much a question of not seeing the wood for the trees, but rather seeing the wood, trees, twigs and leaves in sufficient detail at the same time.

And what was this problem that was occupying the finest scientific and technical minds at the close of the nineteenth century? It was simply this:

Make choo choo go faster

You think I jest. But no: in 1898 the world ran on the power of steam. Steam engines were the shining metal giants that laboured tirelessly where hundreds of millions of men and beasts had toiled in misery before. In less enlightened times, industry had rested on the backs of living things that strained and suffered under their load; now. however, it was built on the back of machines that felt no pain and could work day and night when fed with coal.

So much progress had been made over the years from the clanking primitive behemoths pioneered by Thomas Newcomen and James Watt. Those wasteful old engines had always teetered far too close to the edge of scalding catastrophe for comfort and demanded the tribute of a mountain of coal for a miserly hillock of work.

Modern steam engines were sleeker, safer and more efficient. But they still demanded too much coal for a given amount of work: somewhere, deep within their intricate web of moving parts, energy was wastefully haemorrhaging. No matter how much coal you loaded into the firebox or how hotly it burned, the dreadful law of diminishing returns worked its malevolent magic: the engine would accelerate to a certain speed, but no faster, no matter what you did. You always got less work out than you put in.

Captain Henry Phineas Sankey was searching for a tourniquet that would stem the malign loss of energy in the innards of these vital machines. He could not help but think of the wise words written by Jonathan Swift many long years ago:

Whoever could make two ears of corn, or two blades of grass, to grow upon a spot of ground where only one grew before, would deserve better of mankind, and do more essential service to his country, than the whole race of politicians put together.

What Captain Henry Phineas Sankey hoped to do was nothing less than reverse engineer the venerable Jonathan Swift: whereas previously a steam engine would burn two tons of coal to perform a task, he wanted to build an engine that would do the same work by burning only one ton of coal. That he hoped would be his enduring memorial both of his service to his country and to mankind.

But how to achieve this? How could one man hold in his head the myriad moving, spinning parts of a modern steam engine and ascertain how much loss there was here rather than there, and whether it was better to try and eliminate the loss here which might increase the weight of that particular part and hence lead to an unavoidably greater loss over there . . .

Captain Sankey’s restless eyes alighted on a framed drawing on the wall. It had been painstakingly drawn some years ago by his son, Crofton, and then delicately painted in watercolours by his daughter, Celia, when they were both still very young children. They had both been fascinated by the story of Napoleon’s ill-fated Russian Campaign of 1812. The drawing showed Charles Minard’s famous map of 1869.

It showed the initial progress of Napoleon’s huge army as a wide thick band as they proudly marched towards Moscow and its gradual whittling down by the vicissitudes of battle and disease; it also showed the army’s agonised retreat, harried by a resurgent Russian military, and fighting a constant losing battle against the merciless ‘General Winter’. Only a few — a paltry, unhappy few — Frenchmen had made it home, represented by the sad emaciated black line at journey’s end.

Mrs Eliza Sankey had questioned allowing their children to spend so much time studying such a ‘horrible history’ but Captain Sankey had encouraged them. Children should not only know the beauties of the world but also its cruelties, and everyone should attend to the lesson that ‘Pride goeth before a fall’.

The map showed all of that. It was not just a snapshot, but a dynamic model of the state of Napoleon’s army during the whole of the campaign: from the heady joys of its swift, initial victories to its inevitable destruction by cruel attrition. It was a technical document of genius, comparable to a great work of art, for it showed not only the wood but the trees and even the twigs all at one time . . .

Captain Sankey started suddenly. He had an idea. Unwilling to spare even an instant in case this will ‘o the wisp of an idea disappeared, he immediately clipped a blank sheet of paper to his drawing board. He slid the T-square into place and began to draw rapidly. This is the work that Captain wrought:

Later that evening, he wrote:

No portion of a steam plant is perfect, and each is the seat of losses more or less serious. If therefore it is desired to improve the steam plant as a whole, it is first of all necessary to ascertain separately the nature of the losses due to its various portions; and in this connection the diagrams in Plate 5 have been prepared, which it is hoped may assist to a clearer understanding of the nature and extent of the various losses.

The boiler; the engine; the condenser and air-pump; the feedpump and the economiser, are indicated by rectangles upon the diagram. The flow of heat is shown as a stream, the width of which gives the amount of heat entering and leaving each part of the plant per unit of time; the losses are shown by the many waste branches of the stream. Special attention is called to the one (unfortunately small) branch which represents the work done upon the pistons of the engine

Captain Sankey (1898)

The ubiquitous Sankey diagram had been born . . .

How NOT to draw a Sankey diagram for a filament lamp

Although this diagram draws attention to the ‘unfortunately small’ useful output of a filament lamp, and it is still presented in many textbooks and online resources, it is not consistent with the IoP’s Energy Stores and Pathways model since it shows the now defunct ‘electrical energy’ and ‘light energy’.

Note that I use the ‘block’ approach which is far easier to draw on graph paper as opposed to the smooth, aesthetically pleasing curves on the original Sankey diagram.

How to draw a Sankey diagram for a filament lamp

We can, however, draw a similar Sankey diagram for a filament lamp that is completely consistent with the IoP’s Energy Stores and Pathways model if we focus on the pathways by which energy is transferred, rather than on the forms of energy.

The second diagram, in my opinion, provides a much more secure foothold for understanding the emission spectrum of an incandescent filament lamp.

And, as the Science National Curriculum reminds us, we should seek to use ‘physical processes and mechanisms, rather than energy, to explain’ how systems behave. Energy is a useful concept for placing a limit on what can happen, but at the school level I think it is sometimes overused as an explanation of why things happen.

Closing thought

Stephen Hawking surmised that humanity had perhaps 100 years left on a habitable Earth. We are in a race to make a less destructive impact on our environment. ‘Reverse engineering’ Swift’s ‘two ears of corn where one grew before’ so that one joule of energy would do the same work as two joules did previously would be a huge step forward.

And for that goal, the humble Sankey diagram might prove to be an invaluable tool.

The Apparatus of Golgi: Science As It Should Be

Carl Sagan said that science is unique in having it’s own built-in error correcting machinery:

The scientific way of thinking is at once imaginative and disciplined. This is central to its success. Science invites us to let the facts in, even when they don’t conform to our preconceptions [ . . .] One of the reasons for its success is that science has built-in, error correcting machinery at its very heart. Some may consider this an overbroad characterization, but to me every time we exercise self-criticism, every time we test our ideas against the outside world, we are doing science. When we are self-indulgent and uncritical, when we confuse hopes and facts, we slide into pseudoscience and superstition.

Sagan 1997: 35 [emphasis added]

Of course, scientists are only human, and are sometimes as susceptible to self-indulgence and reluctance to criticise their own “pet” theories as the next person. But not always.

Richard Dawkins (2006) shares the following story about the reaction of a highly respected “elder statesman” of science to evidence countering his long-held opinion about a structure inside living cells called the Apparatus of Golgi (GOL-jee).

An animal cell. The Apparatus of Golgi is labelled 6. For other labels, click on the link https://en.wikipedia.org/wiki/Golgi_apparatus

I have previously told the story of a respected elder statesman of the Zoology Department at Oxford when I was an undergraduate [c.1960]. For years he had passionately believed, and taught, that the Golgi Apparatus (a microscopic feature of the interior of cells) was not real: an artefact, an illusion. Every Monday afternoon it was the custom for the whole department to listen to a research talk by a visiting lecturer. One Monday, the visitor was an American cell biologist who presented completely convincing evidence that the Golgi Apparatus was real. At the end of the lecture, the old man strode to the front of the hall, shook the American by the hand and said — with passion — “My dear fellow, I wish to thank you. I have been wrong these fifteen years.” We clapped our hands red.

Dawkins 2006: 283

References

Dawkins, R. (2006). The God Delusion. Bantam Press.

Sagan, C. (1997). The Demon-Haunted World: Science As A Candle In The Dark. Random House Digital, Inc

Using dimensional analysis to estimate the energy released by an atomic bomb

Legend has it that in the early 1950s, British physicist G. I. Taylor was visited by some very serious men from the military authorities. His crime? He had apparently secured unauthorised access to worryingly accurate and top secret information about the energy released by the first atom bomb.

Sir G. I. Taylor (1896-1965)

Taylor explained that, actually, he hadn’t: he had estimated the energy yield from a series of photographs of the first atomic test explosion published by Life magazine. Taylor had used the standard physics technique known as dimensional analysis.

Part of the sequence of photographs of the Trinity atomic weapon test (16/7/45) published by Life magazine in 1950

The published pictures had helpfully included a scale to indicate the size of the atomic fireball in each photograph and Taylor had been able to complete a back-of-the-envelope calculation which gave a surprisingly accurate value for what was then the still highly classified energy yield of an atomic weapon.

This story was shared by the excellent David Cotton (@NewmanPhysics) on Twitter, and included a link to a useful summary which forms the basis of what follows. (NB Any errors or omissions are my own.)

It is presented here for A-level Physics teachers to consider using as an example of the power of dimensional analysis beyond the usual “predicting the form of the equation for the period of a simple pendulum”(!)

Taylor’s method: step one

Taylor began by assuming that the radius R of the fireball would depend on:

  • The energy E released by the bomb. The larger the energy released then the larger the fireball.
  • The density of the air ρ. The greater the density of the air then the smaller the fireball since more work would have to be done to push the air out of the path of the fireball.
  • The time elapsed t from the explosion. The longer the time then the larger the size of the fireball (until the moment when it began to collapse).

These three factors can be combined into a single relationship:

k is an unknown arbitrary constant. Note that we would expect the exponent y to be negative since R is expected to decrease as ρ increases. We would, however, expect x and z to be positive.

Taylor’s method: step two

Next we think of the dimensions of each of the values in terms of the basic dimensions or measurements of length [L], mass [M] and time [T].

  • R has the dimension of length, so R = [L].
  • E is in joules or newton metres (since work done = force x distance). From F=ma we can conclude that the dimensions of newtons are [M] [L] [T]-2. This makes the dimensions of energy [M] [L]2 [T]-2.
  • ρ is in kilograms per cubic metre so it has the dimensions [M] [L]-3.
  • t has the dimension of time [T].

Taylor’s method: step three

Next we write equation 1 in terms of the dimensions of each of the quantities. We can ignore k as we assume that this is a purely numerical value with no units. This gives us:

Simplifying this expression, we get:

Taylor’s method: step four

Next, let’s look at the exponents of [M], [L] and [T].

Firstly, we can see that x + y = 0 since there is no [M] term on the left hand side.

Secondly, we can see that 2x – 3y = 1 since there is an [L] term on the left hand side.

Thirdly, we can see that z – 2x = 0 since there is no [T] term on the left hand side.

Taylor’s method: step five

We now have a system of three equations detailing three unknowns.

We can solve for x, y and z using simultaneous equations. This gives us x=(1/5), y=(-1/5) and z=(2/5).

Taylor’s method: step six

Let’s rewrite equation 1 using these values. This gives us:

Rearranging for E gives us:

Taylor’s method: step seven

Next we read off the value of t=0.006 s and estimate R=75 m from the photograph. The density of air ρ at normal atmospheric pressure is ρ=1.2 kg/m3.

If we substitute these values into equation 6 (assuming that k=1) we get E= 7.9 x 1013 joules.

Conclusion

Modern sources estimate the yield of the Trinity test as being equivalent to between 18-20 kilotons of TNT. Let’s take the mean value of 19 kilotons. One kiloton is equivalent to 4.184 terajoules. This means that, according to declassified sources that were not available to Taylor, the energy released by the Trinity test was 7.9 x 1013 joules.

As you can see, Taylor’s “guesstimated” value using the dimensional analysis technique was remarkably close to the actual value. No wonder that the military authorities were concerned about this apparent “leak” of classified information.

The Pedagog Teaches PRAD

Queen Mary made the doleful prediction that, after her death, you would find the words ‘Philip’ and ‘Calais’ engraved upon heart. In a similar vein, the historians of futurity might observe that, in the early years of the 21st century, the dread letters “R.I.” were burned indelibly on the hearts of many of the teachers of Britain.

In a characteristically iconoclastic post, blogger Requires Improvement ruminates on those very same words that he adopted as his nom de guerre: R.I. or “requires improvement”.

He argues convincingly that the Requirement to Improve was, in reality, nothing more than than a Requirement to Conform: the best way to teach had been jolly well sorted out by your elders* and betters and arranged in a comprehensive and canonical checklist. And woe betide you if any single item on this lexicon of pedagogical virtue was left unchecked during a lesson observation!

[*Or “youngers”, in many cases.]

But what were we being asked to confirm to? Requires Improvement writes:

It was (and to an extent, still is) a strange mixture of pedagogies which probably didn’t really please anyone.

It wasn’t (and isn’t) prog; if a lesson has a clear (and teacher-defined) success criterion, it can’t really be progressive. Comparing my experience as a pupil in the 1980’s with that of the pupils I teach now, they are much better trained in what to write to pass exams, and their whole school experience is much more closely managed than mine was. 

Equally, it wasn’t (and isn’t) trad; if the lesson model is about pupil talk, or putting generic skills above learning a canon of content, it can’t really be traditional teaching.

I think that Requires Improvement has hit the nail squarely on the head here. What we were being asked (and in many schools, are still are being asked) to do is teach a weird hybrid Frankenstein’s monster of a pedagogy that combines seemingly random elements of both PRogressive and trADitional pedagogies: PRAD, if you will.

As C. P. Scott said of the word television that no good could come of a word that’s half Latin and half Greek, I feel that no good has come of the PRAD experiment.

While many proponents of PRAD counted themselves kings of infinite pedagogic space, congratulating themselves on combining the best of progressive and traditionalist ideologies, the resulting unhappy chimera in actuality reflected the poverty of mainstream educational thought.

But though our thought seems to possess this unbounded liberty, we shall find, upon a nearer examination, that it is really confined within very narrow limits, and that all this creative power of the mind amounts to no more than the faculty of compounding, transposing, augmenting, or diminishing the materials afforded us by the senses and experience. When we think of a golden mountain, we only join two consistent ideas, gold, and mountain, with which we were formerly acquainted.

— David Hume, An Enquiry Concerning Human Understanding (1748)

Rather than a magical wingèd lion that breathes fire, PRAD is a stubby-winged mishmash that can’t fly, can’t lay golden eggs, and that spends its miserable days hacking up furballs. It is time to put it out of its misery.

Brownian Motion, Staff Rooms and Bromeliads

Individuals aren’t naturally paid-up members of the human race, except biologically. They need to be bounced around by the Brownian motion of society, which is a mechanism by which human beings constantly remind one another that they are…well…human beings.

— Terry Pratchett, Men At Arms

Happiness is . . . not having an office.

I had a job once where I had an office. It was a quite a nice office. And I had it all to myself. It was a quiet, pleasant little space with a small kitchen nearby. It even had natural daylight through a large window Perfect, you might think.

But I grew to hate that office. You see, I think that teachers — more than anyone, perhaps — need, occasionally, to be “bounced around by the Brownian motion of society”. 

What is Brownian motion? Well, it was first observed by botanist Robert Brown in 1827, who noted that, under a microscope, pollen grains in water seemed to “jiggle” randomly. Brown at first assumed that this motion was due to the “life force” of the pollen grains; however, he dispensed with this idea when he saw particles of stone dust (reportedly taken from the Great Pyramid to make sure they were completely and utterly devoid of life) perform the same drunken, wiggly waltz that came to be known as Brownian motion.

And there the matter rested, for a while. And then in 1905, a young patents clerk, working in his spare time at a kitchen table in a very modest apartment in Geneva, suddenly discovered the explanation — and more, much more.

The patents clerk’s name was, of course, Albert Einstein. His explanation rested on the insight that the visible pollen or dust particles were being buffeted by invisible water particles. His mathematical analysis was not only the first verifiable evidence of the actual physical existence of atoms, but also established their size. Understanding the movement and nature of the unobservable by minute and careful scrutiny of the observable…

Looking back at the job with its own office, I think I missed the simple daily dose of teacherly Brownian motion that you get by simply stepping into a staff room. Are you a little too-full-of-yourself-by-half? Some friendly ego-puncturing banter is usually on tap. At your wit’s end with a difficult student or class? A sympathetic shared eye-roll can work wonders. Plus there might even a few good ideas thrown in for good measure.

A good school staff room is not always synonymous with a “good” school, but a good staff room can make even a “bad” school bearable — enjoyable, even! — and the lack of one can make even an “outstanding” school feel like a souless and joyless treadmill.

If you are being interviewed by more than one school, choose the one that has the beat-up, well-used furniture in the staff room, replete with dirty coffee mugs and tottering piles of unmarked marking whose lower layers are being spontaneously formed into sedimentary rock by the crushing pressure from above.

Sadly, I feel that that this type of staff room is a vanishing phenomenon. I suppose that I am like a dinosaur complaining that bromeliads these days don’t taste as nice as the bromeliads they had in the old days.

Teachers today just aren’t rubbing elbows as much as they used too. H’mmm. Maybe that’s why we don’t have to wear elbow patches any more…

But that does not detract from this universal truth that should, I feel, be more universally acknowledged: if a staff room is suspiciously neat and clean and looks like an airport lounge…RUN AWAY!

The Gamesters of Sparta

Sir. It must be considered, that a man who only does what every one of the society to which he belongs would do, is not a dishonest man. In the republick of Sparta, it was agreed, that stealing was not dishonourable, if not discovered.

— Samuel Johnson

At a recent event, the speaker asked us to consider a hypothetical conundrum: what if one GCSE Triple Science student was strong in (say) Chemistry and Biology, but significantly weaker in GCSE Physics? 

What course of action would you recommend? Extra support in Physics, was the consensus reply. 

Actually, said the speaker, the smart “Progress 8 Maximisation Strategy” would be to:

  1. Tell the student to focus her efforts entirely on Biology and Chemistry and completely ignore Physics. . .
  2. . . . but keep her entered for GCSE Physics anyway, and make sure that she goes into the exam hall and writes her name on the Physics papers, even if she does nothing else.

That way, she has ostensibly followed a full and balanced curriculum. She has, after all, been entered for all three Science subjects.  And, since Progress 8 counts only the two highest Science grades (or so I’m told), the student’s contribution to the school’s league table position would be also be secure.

H’mm. Dishonest? No. In the school’s best interests? Definitely. In the student’s best interests? Erm . . . on balance, no.

Sadly, as the character Joseph Sisko (ably played by Brock Peters) once observed on Star Trek: Deep Space Nine: “There isn’t a test that’s been created that a smart man can’t find his way around!” And that includes Progress 8 . . .

Sir, I do not call a gamester a dishonest man; but I call him an unsocial man, an unprofitable man. Gaming is a mode of transferring property without producing any intermediate good. 

— Samuel Johnson

Gizza Teacher

Few who watched the TV series Boys From The Blackstuff back in 1982 could forget Bernard Hill’s affecting portrayal of Jimmy “Yosser” Hughes’ mental breakdown, as a man whose job was an integral part of his self-image struggled to come to terms with being laid off. Yosser walked the streets of Liverpool, desperately looking for a job — any job! — and plaintively asking anyone who would listen: “Gizza job. I can do that!” (“Give us [me] a job” as Wikipedia helpfully translated for non-Scousers.)

What brought this to mind was an advert for a science teaching job that I stumbled across recently which stated “No long written statement will be required”(!)

Those famous lines of W. B. Yeats occurred to me:

Things fall apart; the centre cannot hold;
   Mere anarchy is loosed upon the world

And for why?  Well, the application process for any teaching job has always tended towards the recondite, rococo, recherché and — dare I say it? —  the ridiculous.

First, there was the dreaded application form, which was anywhere between four and six pages long. Always the same information required, but always in an annoyingly different format, seemingly designed with fiendish cunning to prevent cutting and pasting from any previous application form.

Second, there was the hell of writing the personal statement: write several hundred words on . . . you. Just you. “Tell us what makes you so fabulous and great. Focus on the outcomes of the many initiatives that you have recently spearheaded, both within your department and in a broader whole school context.” This type of writing does not come easily for us introverted sciencey types, I can tell you.

The fact that many schools are now openly willing to reduce the number of “application hoops” that candidates have to jump through is, to my mind, very telling. It indicates how deeply the recruitment and retention crisis is biting.

It now seems to be schools who are scouring the country, plaintively crying “Gizza teacher!” Strange times indeed.

Feeling Lucky?

Napoleon’s generals not only had to be loyal, brave and skilled in arms (obviously enough), but the Emperor also demanded of them a more nebulously indefinable quality. When others in his entourage would laud the skills of a particular soldier, Napoleon would ask the pointed question: “Yes, but is he lucky?”

It seems to me that being lucky is the quality that, these days at least, is the one most valued in teachers by those in power above them. The old adage about success having many fathers but failure being an orphan was never truer than in today’s educational world. Examination results, or “outcomes”, are the bit-coin currency of choice in the go-getting world of “performance management” and “high stakes accountability”.

Forgive me, but I am awearied of all that talk. More and more I feel something akin to Duke Ellington’s response to long-winded analyses of the magic of jazz as being “talk that stinks up the room”.

In my career, I have faced Triumph and Disaster in terms of results. Although Kipling advised us to treat “those two impostors just the same”, the truth is that we don’t. Few human beings can. Our perceived Triumphs make us arrogant, the Disasters make us hostile and defensive.

And yet, I think I begin to see a pattern. 

My triumphs occurred when I just got on with the business of teaching: turning up, teaching solid straightforward lessons, setting and marking regular homework. I remember one (internal) observer asking a student about their past paper practice question booklet, returned with a simple percentage grade (in red pen), “And how often are you set homework like this?” and the student answering matter-of-factly: “Every week”. I was so proud. That said, the observer still gave me a “3 (requires improvement)”, citing “lack of pace”, “no plenary” and “no feedback” (when they actually meant no written WWW/EBI comments). But I carried on regardless. And that year’s results were amongst my best ever.

My Disasters seem to occur when I am scrabbling manically to follow what is currently lauded as best practice. In other words, trying to copy what other schools do — or perhaps, more accurately, what other schools say that they do — badly.

Coincidence? Possibly.

So, am I a lucky teacher, in the Napoleonic sense? Sometimes, when I have the good sense to follow my experience and instincts, rather than fads and fashions.

So what about you, when faced with the russian roulette lottery of exam results (you do know it is just a lottery, right?): Are you feeling lucky, punk?

The Joy of a Cheese Sandwich

O tempora, o mores!

What times! What customs!

— Cicero

We are all orthorexics now.

Or so it would seem, at least to me. Orthorexia is the obsession with eating foods that the individual considers ‘healthy’. When I started teaching, a typical teacher’s packed lunch consisted of a sandwich, an apple and a packet of crisps. This was such a common combination that I remember one wag saying that such unthinking adherence to culinary group-think would even have brought joy to the heart of Josef Stalin.

But now — oh my goodness me! What times! What customs! What a huge selection of weird and wonderful Tupperware!

And the food! Growing up in North Wales in the 70s, I’m sure that the majority of food being ingested in our staff room would not have been available in most supermarkets. Perhaps not even in Llandudno ASDA where my parents, cosmopolitan souls that they were, would venture every now and again to buy exotic packets of VESTA dried foods.

But enough of Vesta packets (my favourite was the Beef Risotto, especially eaten as a sandwich), what kind of modern foods am I talking about? Examples would be Black Lentil and Aubergine Stew (“Because black lentils are so much more nutritionally dense than your everyday red lentils, darling!”), Kale and Lemon with Giant Couscous Salad or Smoked Mackerel Pilaf.

Oh lordy, it’s enough to make a chap self-conscious about his cheese sandwich, apple and packet of crisps. Except . . . the way I look at it is: food is food. The human organism is evolved to ingest any old random crap that either can’t or doesn’t run away fast enough and turn it into, well, human-stuff: snot, phlegm, fingernails parings, earwax and so on. A human being can survive for a surprisingly long time on “empty” calories, provided that a few trace nutrients are also present (“Scurvy, anyone?”).

What I do find strange about the now almost universal orthorexic mindset is the attribution of near magical properties to food-stuffs, especially the less familiar and exotic ones.The power of a secretary of state of education seems as nothing compared to that of Jamie Oliver.

That said, there is cause for concern in the amount of processed sugar consumed by youngsters and well, everyone else actually. But I cannot help but feel that there is a strong element of public performance, and perhaps even “nutritional virtue signalling”, in the eating patterns of many adults today.

    P is for Progressive, T is for Traditionalist, Z is for Zealot

    The change of religion in Scotland, eager and vehement as it was, raised an epidemical enthusiasm, compounded of sullen scrupulousness and warlike ferocity, which, in a people whom idleness resigned to their own thoughts, and who, conversing only with each other, suffered no dilution of their zeal from the gradual influx of new opinions, was long transmitted in its full strength from the old to the young . . .
    — Samuel Johnson, A Journey To The Western Islands Of Scotland [1775]

    Old Andrew writes of a recent case in Scotland where a teacher was barred from teaching for two years because, for example, she “did not refer to success criteria” and “failed to recap the learning intentions at the end of the lesson”(!)

    Well, to some extent I have been there, done that and got the t-shirt. I have been on the receiving end of the ‘support’ that doesn’t feel particularly supportive. However, it has never reached the disciplinary stage; in part, I suppose, because I learned to ‘play the game’ and stick in a few card sorts and the like. Teacher, know thou thy observer!

    But I feel I have known what might be termed the “epidemical enthusiasm” of True Believers in the now defunct ‘Axis of Old-style-Ofsted’ model. And, yes, there was indeed a time when it seemed that many who favoured that model conversed “only with each other” and that there was no hope of any dilution of their zeal.

    It is depressing to think that these discredited ideas still hold sway in parts of our education system.

    That said, it seems to me that this is not automatically a consequence of progressive ideals; rather, it seems to me a consequence of a totalitarian mindset — an inability to trim one’s ideological sails to the winds of empirical reality, especially when one is in a position of power or authority.

    And that, I think, is something that each of us — Positive Traditionalist* or Positive Progressivist* alike — needs to guard against.

    *See @heymisssmith’s excellent post for further explanation of what I think is a useful expansion of the traditionalist vs. progressivist terminology.