He’s making a list, and checking it twice; gonna find out who’s naughty or nice…
Santa Claus is Coming’ to Town, by John Frederick Coots and Haven Gillespie
Read. Check. Tick. Move down, that’s done, tick.
We undoubtedly take a certain pleasure in going through a list and ticking off all the things that we’ve already sorted out, item by item. It gives a comforting illusion of order, the impression that we are getting back control over our lives, letting go what’s unnecessary and keeping what matters. Decluttering is an essential need. At times, all we really feel like doing is tidying up, and making sense of the mess that inevitably tends to build up when we go about our daily business.
This is particularly true at the turn of the year, the perfect time to wrap it up, to winnow the wheat from the chaff (in plain English: pick what to keep and what to chuck). The end of December and New Year’s Day are especially conducive to lists. We’ve got, of course, the wish list par excellence, the one we submit to Santa for approval, and, like any other manuscripts (we’re scientists, after all) can be accepted, returned for revision or outright rejected. Except for the last case, we can safely say that writing of presents is a very pleasant pastime – reward circuits hardwired in our brains must fire in anticipation of the upcoming treat.
The dreaded “New Year’s resolution” list is another cup of tea: we all remember how it went last time, we all know we’re bound to fail, and yet we shall fall into the old bad habit of sitting down and drawing up the infamous list, once more, as the dying year is about to flicker out. Frustration, as it seems, will inevitably hit back on the third Monday of January, jokingkly considered the most depressing (a.k.a “Blue Monday“).
And then…there are those lists that you don’t even have to write (unless you are a journalist): you can just sit back and enjoy reading the selection of the most remarkable events or the greatest hits of the year while sipping mulled wine. “The best of (add year here) in (choose a topic)” is a classic late-December theme. Everyone seems to want to have a go at it: from authoritative dictionaries (the Oxford Dictionary Word of the Year 2017 is youthquake) and high-impact scientific journals (Science‘s 2017 Breakthrough of the Year is cosmic convergence), to Chemistry magazines or blogs, and finally TV programmes at a loss for ideas.
Arguably, one of the perks of being a scientist – apart from enjoying PhD Comics and going through your e-mails at a New Year’s party – is that you don’t have to wait until December to read ‘best of’ lists: review articles regularly come out all year round. Apart from generalist, flagship titles such as Chemical Society Reviewsand Chemical Reviews, there are other journal publishing collections of review articles. Among them, the series Current Opinion in (add topic here) aims to address scientists’ need “to keep up to date with the expanding volume of information published in their subject” (in the publisher’s own words). With new issues every two or three months, these journals publish review dealing with a very specific topic.
We the electrochemists are fortunate enough to have our own Current Opinion in Electrochemistry, launched in January 2017 and reflecting the current fad fortoday’s renewed interest in electrochemistry; after all, “Never has electrochemical science been more active! Nor has the world seen so many electrochemists!”, as the Editors remark, somewhat echoing Churchill’s rhetorics. The scope and aim of the journal, outlined on the journal homepage, reflect a clear vision: articles should be “clear and readable”, while the vast domain of electrochemistry is broken down into twelve “themed sections”. As far as I can tell, articles in Current Opinion indeed tend to be a more digestible fare than the comprehensive yet usually oh-so-lengthy typical review.
Current Opinion in Electrochemistry has just turned one (offering access to a selection of articles free of charge – a Christmas present of sorts?), and so I find it tempting to look at all the published reviews as yet another end-of-year “best of” list. Inappropriate? I don’t really think so, because, in the end, authors have to be invited (by the editors) before they can write a review. This means that, apart from being recognised as leading scientists in their own research fields, perspective authors also need to have good connections – which never hurts: ‘networking’ has always been part and parcel of the practice of science. By incorporating this twofold prerequisite for selection, these collections of reviews end up reflecting both scientists’ impact and their visibility ‘beyond their science’; as such, these reviews not only provide an overview of the state of the art, but also the closest thing to a “Who’s Who” in contemporary electrochemistry.
However, what I want to focus on is not the authors themselves or editorial choices – as a humble postdoc, how could I dare defy the foremost authorities? Picking out certain authors and not others could also bruise someone’s ego and put me between a rock and a hard place – not the wisest resolution for the starting year.
Instead, I want to take a spatial turn: an analysis of the affiliations of the authors of the articles published in the first eight issues (six for 2017, plus two in progress and already available online) is a simple approach to mapping out electrochemistry on a global scale. Because I wanted to devote my holidays to (more interesting) pastimes (such as finding ways of braving the harsh cold wave gripping most of Canada), I have kept it simple and I would never claim that my analysis fulfills rigorous statistical criteria and the likes. In short, I have just avoided counting authors twice and, in the case of multiple affiliations, I have tallied both. By the way, I had to do it manually – which kept me busy for the best part of an afternoon a few days ago as I was coming down with a nasty cold.
The resulting “atlas of electrochemistry in 2018” features clusters of countries and some archipelagos isolated amidst empty oceans, a weird planet in which entire continents disappear. Two superpowers stand out, the US and China, followed by other significant players on the global scale such as France, Japan, the UK and, maybe surprisingly, Spain, which outscores Germany. Taken as a whole, Europe is a global leader, a force to be reckoned with. Despite the clear limitations of my analysis (based on a single collection of reviews), the map is a useful snapshot of the leading centres of electrochemical research in 2017 as seen through the lens of their own peers. It also closely compares with more general trends in chemistry publications1 in 2017.
Has it always been like this? The answer is surely no: the global dominance of nations waxes and wanes, in football and science as in geopolitics. Nevertheless, it is quite hard to set out to compare the present situation with, say, that of fifty years ago, and for many different reasons. It would be too boring to address them here at length. Suffice it to remind that, in the Cold War era, electrochemistry and scientific research in general took place in a “divided world” (to echo the title of a Springer book I would like to read, but that is not exactly very affordable).
What lies ahead
As 2018 is about to start, two science powerhouses intensely compete for dominance, against the backdrop of global geopolitical trends and growing international mobility and collaborations. The analysis of the articles in Current Opinion in Electrochemistry shows that this discipline is very multipolar, and we can confidently expect it to become increasingly so, in the wake of changing trends in R&D funding.
Trying to forecast what is to come is one of New Year’s classic “trivial pursuits”, and, like good resolutions, one usually bound to fail. That’s why I won’t yield to the temptation to play the soothsayer: I’ll make no prediction on World Cup or Nobel Laureate winners for 2018. I’ll just send you, my patient readers, my warmest wishes for a wonderful 2018.
[…]And if you can’t shape your life the way you want,
at least try as much as you can
not to degrade it[…]
[…]Κι αν δεν μπορείς να κάμεις την ζωή σου όπως την θέλεις,
τούτο προσπάθησε τουλάχιστον
όσο μπορείς: μην την εξευτελίζεις[…]
(As much as you can – original title Όσο Mπορείς, by C.P. Cavafy, Greek text available here, English translation here)
1. According to Web of ScienceTM, of the 31809 records classified as “chemistry” and published in 2017, 25% contain an affiliation in the US, 19% in China, 10% in Germany, 8% in the UK and 7% in India. France, Japan, Spain, Canada and Italy are the remaining countries in the Top 10.
The European scientist was a member of the intellectual class, dressed in a three-piece suit, watch chain across the vest and wearing a carefully trimmed beard or goatee[…]The American scientist is dressed practically, either in the lab coat or working man’s clothes. His clothes carry with them no hint of social rank, just as the monk’s habit abolishes the distinction of class at birth. The new scientist was clean-shaven, with short, slicked down hair. This reflected the new fashion for men of the day, especially in the U.S. and it also made clear that these men were progressive, concerned with the needs of the market, and distinct from the old professors. The new scientist was also pictured, metaphorically and literally, with his sleeves rolled up and getting down to work.
A glorious summer afternoon filtered its blindfolding light through the foliage of the trees that flanked the side-street. We were strolling leisurely along the pavement, moving from sunny to shady cases like chess pieces shuffling quietly over a chequerboard, when I suddenly caught sight of him. A man was looking at us from his balcony. He must have been watching the passers-by to kill time. Small tired pupils peeped through slits, his cigarette hanging at a slant from his pursed lips. We could smell his gaze following us as we walked and inhaled the invisible smoke. We turned the other way, and our eyes breathed something else in, absorbing another kind of vapour, one that words emit, highly addictive if you yield to it.
An overdose of poetry.
They were hanging from trees – hey, wait a second, I’ve been scooped! That was my idea, hanging poems here and there– dozens of poems printed on corrugated plastic sheets. The street, lined by short compositions and excerpts from longer ones, turned into a poetic hypertext, and you could zigzag from verse to verse, from side to side. Your path then became itself poetic word, an enjambement across the centre line.
We gathered at the street corner for a poetry reading; the poets were randomly scattered among the bystanders, and it was obviously impossible to spot them before they stepped up. It was at this stage that my mind started drifting away, summoning up the sterotypical images of poets inspired by novels and paintings: the dandy and his walking stick, the penniless romantic with scruffy hair, the academic attired in waistcoat and black tie…
…I startled, a ripple of applause followed a poem, shattering the silence and those stereotypes, smashing them like cold, voiceless glass figurines in a recycling bin.
Instead, these poets are very much alive, they read their compositions aloud, giving voice to everyone of us in the audience, here, now. They walk the city with us, they tread its uneven pavements, they crush the splinters of cracked beer bottles under their shoes, only to craft an ocean from this archipelago of shards. Sometimes they are slovenly dressed, like aging rockstars, with unkempt flowing hair and a tatty old sleeveless T-shirt. Appearances deceive: their hands tremble as they read their verses. Otherwise they sport a trendy cloth cap, a well-groomed beard, a cigarette dangling from their lips: a little girl listens to dad’s poems talking of the hidden lane where she and her friends play hopscotch, where the wrought iron staircases spiral downwards. It seemed to me that these poets perfectly embodied Wallace Stevens’ definition of modern poetry, in Of Modern Poetry:
It has to be living, to learn the speech of the place.
It has to face the men of the time and to meet
The women of the time
“So much for my poetic stereotypes” – I said to myself, tongue-in-cheek, as I was looking at the distorted image of my face in a car wing mirror; then I wondered: “Well, what about chemists, then?”
Lab coat anyone?
Say chemist, see a lab coat on two legs. Maybe. The lab coat is indeed a fascinating example of a powerful, long-lived metonymy that has become deeply ingrained in popular culture. Yet, there is much more to say about it.
For instance, this metonymy that we almost take for granted is approximately a century old, and its origins are associated with development in photography and shifts in the self-image that chemists, or scientists, wanted to promote among the laypeople:
“There is some debate about when scientists were first shown in lab coats. [This] does not represent a new image, but rather an important interpretation of the image that contributed to the creation of a powerful visual metonym in the public sphere. The use of the lab-coated scientist as a metonym does not have a single source of origin. In part, it evolved from images of chemists and other scientists at work, where they often wore aprons or light overcoats to protect their suits. As photography improved, candid pictures of scientists at the lab bench became more common by the 1920s, so the wearing of the lab coat came to be associated with a scientist at work. The other source of the image came from physicians, who started wearing white overcoats and aprons in the late 19th century and were far more likely in this period to be pictured in their white overcoats than most scientists.”1
“Scientist at work”. This is the key point. Although I enjoy finding similarities between chemists and poets, there is a fundamental difference with respect to the actual place where they let their creativity unfold. A poet can be a poet anywhere; instead, a chemist needs a lab to engage with the material world. I believe that this peculiar space, somewhat isolated from the rest of the world2 where ideas, matter, and human agency interact, requires for the chemist to “switch” to laboratory mode by putting on a white coat. In a sense, I see the lab coat as a uniform that chemists need to don, not only because of safety concerns, but in particular because this unique garment is instrumental in putting the chemist in the right mindset before an experiment much as a jersey, a pair of boots, and shorts allow someone to become a player of a certain football squad. Additionally, I find it really fascinating that the white coat is an international metonymy of the scientist at work, which is a powerful antidote to the resurgence of national identities and socially divisive symbols which is sadly so rampant these days. Lab coats of the world unite.
That said, I must recognise that the white coat seems to experience fluctuating fortunes, and I speak from personal experience. Despite the widespread adoption of risk assessment practices and the improved safety records of academic laboratories, the approach to accident prevention remains “more relaxed” than in industry 3. Take for example the tragically famous mortal accident that occurred at the University of California, Los Angeles, in late 2008 . The investigations into the accident, and the ensuing trial, uncovered violations of “occupational health and safety laws“. The research assistant was not wearing a laboratory coat when the compound that she was handling, t-butyllithium, caught fire, spreading to her clothes, thus causing fatal burns? Would a lab coat have saved her life? That is extremely hard to say.
However, I believe that the (apparently) mixed fortunes of the laboratory coat cannot simply explained simply a matter of a laissez-faire attitude displayed towards safety: I strongly suspect that apart from unsafe practices in the lab there must be something else at play, perhaps a growing intolerance towards this cumbersome item of clothing that makes all chemists look identical. Something utterly unbearable in the age of personalisation, where “be different” is a mantra that we hear over and over again. Oh, well, but you could always write something on the white coat to customise it, as we used to do as teenagers back at the technical school for chemistry. Never mind…
Anyway, it is clear that the same fate does not lie in store for the other fundamental items of personal protective equipment, that is, safety eyewear in all its forms (goggles, spectacles, etc.). Throughout my career as a chemist, I have very, very seldom seen someone neglecting eye protection, or making light of potential eye damage, and this stands in stark contrast to what I wrote above about the laboratory coat. It seems that getting holes or destroying your clothes is perceived as a sort of acceptable risk (I will return to this point later on), while eye injuries, and the appalling images that they evoke, are enough to crank up every chemist’s vigilance. Tus ojos no tienen repuesto, ‘your eyes have no spare parts’, read a sign on the door of a laboratory at the University of Alicante, Spain, where I worked for a few weeks, and this short but effective slogan has stayed with me ever after. Apart from common sense, there must be something subliminal about this warning, and I wonder if it plays on chemists’ ancestral fears: the ever-impending danger of losing an eye to explosions, or other accidents may be, in this respect, a meme passed from one generation of chemists onto the next. Illustrious chemists have paid such a price while carrying out their research (Bunsen and Sharpless3 to name a few). This fear also surfaced in an interview by Primo Levi about his life, Il segno del chimico (“The chemist’s sign”), when Levi recalls an excerpt from his practical organic chemistry textbook, the venerable Die Praxis des organischen Chemikers by Ludwig Gattermann:
“Il più importante organo da proteggere è l’occhio. In tutte le operazioni che si svolgono sottovuoto o sotto pressione, ad esempio per le distillazioni sotto vuoto, o quando si pratichi per la prima volta il vuoto in un essiccatore nuovo, o quando vengano manipolati tubi di vetro a fusione, bottiglie a pressione, autoclavi, si porti sempre un paio di robusti occhiali protettivi, muniti di vetri spessi. Lo stesso vale per l’esecuzione delle fusioni alcaline, e per tutte le operazioni in cui si possano verificare spruzzi di sostanze caustiche o facilmente incendiabili: primi fra tutte,il sodio e il potassio metallici”
“The eye is the most vulnerable organ. Safety glasses with sturdy lenses must be worn while carrying out all operations under vacuum or under pressure, for example vacuum distillations, or while operating vacuum desiccators for the first time, or when handling fused glass tubes, pressure flasks, autoclaves. Similarly, safety glasses must be worn at all times when carrying out alkaline fusions or during operations that can throw sprays of corrosive or highly flammable materials, first and foremost metallic sodium and potassium” 4
Let me finally say something else about the laboratory coat. I believe that the expression “white coat” does not really apply to chemists. No matter how hard you try, the coat will never remain white, and, please be careful, I do not mean to say that most chemists are careless and enjoy splashing coloured chemicals on their overalls. A laboratory can be an extremely dusty place, for example, with window sills placed behind massive equipment, out of the reach of dusters. Or, take fumehoods dedicated to the handling of strong acids: their sashes will inevitably rust, and striping your coat red with iron oxide is just a matter of time.
So here is the chemist at work, wearing safety spectacles, a no-longer-white laboratory coat, and closed shoes – no sandals, please! But what can we say about chemists’…well, ‘plain clothes’ ?
The parts and the hole
I have always thought, or assumed, that the chemist’s clothing preferences should be shaped by purely practical reasons. Chemistry is a hands-on science, after all, and flirting with stuff sometimes turns into a messy affair, in spite of lab coats; so, a chemist going to work – I believe – had better avoid wearing that pair of perfectly tailored pinstripe trousers, and varnished shoes. Just pull on those scruffy jeans, and a tattered (polo, T-) shirt, and this will do. As much as I am concerned, I subscribe to this doctrine…and maybe that’s why I advocate it! Joking aside, clothes are never fully safe in a laboratory. Droplets of corrosive liquids could inadvertently drip out of a pipette, and that’s it. By the way, the damage that concentrated acids and bases inflict to fabric look quite different (and I’m saying this on the basis of some very empirical evidence). Acids are more blatant: they will invariably make holes, upon contact or after the first cycle in the washing machine. After all, highly concentrated sulphuric acid burns through paper. Alkaline solutions, on the other hand, exert a subtler effect: they will leave a discoloured stain, but the change in colour will depend on the concentration, ranging from a faint shadow to major bleaching. (1 M NaOH will leave a somewhat greenish spot if spilled on paper).
Guess what? Alkaline treatment of cotton thread is a commercial process known as mercerisation. Sodium hydroxide “has the effect of swelling the cotton fibre. It converts the fiber from the shape of a ribbon to that of a rod with circular cross-section“5. This process is named after its inventor, John Mercer (1791-1866), a self-taught British chemist whose success story is a veritable riches-to-rags-to-riches tale6 ending with his election as Fellow of the Royal Society. Born to a Lancashire family who owned a spinning mill, Mercer had to start working at the age of nine after his father died – his death being a dramatic epilogue of the terrifying sequence of financial disasters suffered by the Mercers. Eventually, our hero, who in the meantime had become a weaver in his teenage years, took a passionate interest in dyeing. Mercer was hired as apprentice in a colour shop in 1809 but an economic downturn in the printing industry forced Mercer’s employers to lay off staff. The apprentices, at the bottom of the pecking order, were of course those who bore the brunt of the recession. Sounds familiar? Anyway, Mercer had to fall back on his previous trade “with regret”. What follows6 is an anecdote relating Mercer’s random encounter with chemistry:
“It is related that on his way to get his marriage license he stopped at a stall
to purchase a few books. One of these was a used copy of the “Chemical Pocket Book” arranged in a “Compendium of Chemistry” by James Parkinson of Hoxton“
So, when you are rushing somewhere and you happen to spot a roadside bookstall along the way, listen to that voice, don’t be in a hurry, don’t walk on. Always stop and rummage through the piled-up second-hand books. You can never know what you can find in such a treasure trove. At the very least you can buy something to read while you are standing in the endless queue at the register office…(Mercer did eventually get married!).
In 1817 Mercer discovered the new dye antimony orange (antimony trisulphide), while the patent for mercerisation was filed in 1850. The rest is history.
Casual-chic: the scientist’s style
From Mercer to the fashion industry, the question is: does the no-nonsense attitude to clothing (call it poor dress sense if you like) carry over into a chemist’s …’off-duty’ clothing style? Not really, I think. My experience at several international conferences tells me that chemists can be as fashion-conscious as anyone else. A curious fact? Over the course of the last few years I have noticed that there is a fashion label which seems to be all the rage among scientists. In my eyes, this is completely inexplicable, and it is most likely a typical case of pandemic spread of consumer tastes. When in doubt, just follow the crowd. I wonder when this trend emerged, and who set it. In fact, fashion can cross all barriers of discipline or age: I have spotted lots of (male and female) physicists, chemists, engineers, from first-year PhD students to forty-something professors, wearing the same range of preppy sweaters and shirts with the striped blue-white-red logo. These designer clothes invariably look casual-chic, and I think this is a killer combination that resonates with the scientist’s contemporary self-image, which hyphenates the desire to dress smartly with the will to break with the traditional suit-and-tie conference dress code. Or, maybe, the sporty look of this fashion label is an unconscious (Freudian?) way of covering up the sedentary lifestyle which is often part and parcel of the long-hour culture in academia.
Chemist-spotting is then quite a daunting task unless you are in a laboratory, and there is no birdwatching guide to help you. Yet, are poets and chemists birds of a feather?
Coda – a path cut from same cloth?
After all, you could easily get it wrong. Say you have come across someone who is wearing ripped, faded jeans, and this person could well either be a chemist bearing the scars of corrosive liquids, or simply that poet next door going out on a walk downtown. Wandering around the city, or in other words doing a déambulation poétique (‘poetic strolling’), is an approach to writing that I have only recently discovered. The act of strolling through the streets, while feeling the very heartbeat of the urban setting, turns into a pulse that informs the rhythm of the verses. The chance encounters, the pictures snapped along the way, the bustling city teeming with life, outline the framework of the poem. The wandering mind disconnects from pre-existing ideas and opens up, becoming more receptive, perfectly poised for inspiration, while also avoiding wallowing in nostalgia.
In a talk, the poet Hector Ruiz, who has extensively worked on the déambulation poétique, described the figure of the écrivain déambulateur (‘strolling writer’) pitting it against the écrivain migrant (‘migrant writer’). The former strolls and explores the space of the city to feel the resonance of the self with the world here and now, thus loosening the inner shackles forged by the past, while the latter remains handcuffed, burdened with a heavy emotional baggage, a ballast that effectively blocks and impairs writing.
“Il y a un ici, un lieu à habiter, un espace et un langage à découvrir. La ville et la feuille”7
“There’s the here, a place to live, a space and a language to discover. The city and the sheet.”
Walking can set you free and open up your horizons, but if and only if you are willing to challenge yourself, letting yourself be challenged by what you see along the way . Indeed, sometimes it takes a detour around oneself to find the shortest route towards poetic creation. There is just one rule: drift on the flow that pulses through the veins of the city, fall into step with it: play the game, and you will not be playing the same old tune yearning for a long-lost time, but you will be singing something different, unbeknownst to yourself.
Any migration is a form of death, invariably accompanied by mourning; yet, another type of movement in space can side-step it, and that is strolling. There is no way back; exploring the unchartered territory of the city is a forward-looking antidote to the merciless, irreversible exile from the past. Put yourself to the test, follow the cracks on the city pavements, those fault lines that mirror yours, those that scar you deep within. Unzip yourself, wear your tears, acknowledge them, because these open wounds are permeable membranes that set up a two-way traffic across one’s own borders: the desire to engage the city allows it to engage you, too.
Let’s take a break from strolling for a while to stop and think. There is something familiar in Ruiz’s sketch of the strolling writer’s attitude. In a sense, it reminds me of my description of the chemical and poetic inspiration in a previous post. More precisely, the strolling writer seems to combine the best of both worlds: the receptivity of the wandering mind, primed for that cue that will trigger poetic composition, along with the ability of to ‘feel’ the texture of the world that one is exploring, something that I associated with the chemist’s hand at work. Ruiz describes clearly that defining moment (éclaircie – ‘sunny spell’, a flash of lightning) when inspiration sends ripples through that open gate. It is a voice, a vibrating pattern with its own characteristic frequency, defining a language, a pulse: riding the wave, letting it carry you along, is the only way to harness its force. All inspiration is resonance, all poetic composition is the result of impinging wave and of the inner structure.
Like in X-ray diffraction.
Or as good old philosopher Gaston Bachelard would say: “Le spectacle extérieur vient aider à déplier une grandeur intime.“, “The exterior spectacle assists in unfolding an intimate dimension” 8
Moreover, the idea of pinpointing defining features of the urban settings of the déambulation as waymarks guiding the poetic composition has a distinctive flavour that tastes like the mapping out of the energy landscape of a molecule, or a reaction. Map out, yes, I stress the word, because the poetic strolling and computational chemistry will draw a more or less fine-grained image, a reference grid that the poet will then flesh out, or the chemist make sense of.
At this stage, I would like to ask this question: is then chemical research a form of strolling, too? The exploration of the material world, the sudden twists and turns, the unexpected serendipitous discoveries, the continual challenge to one’s own ideas and hypotheses, and the struggle to follow that trail that you think you have seen…indeed, there seems to be a form of déambulation in the lab. To answer this question, I could also look at a chemist who has crossed borders and boundaries, within chemistry, between disciplines, and between science and the humanities: Nobel laureate and poet Roald Hoffmann. In a short article, he stressed that “building bridges” has been a defining feature of his twofold career as scientist and writer, and this image of a movement that overcomes a separation (central to the reflection on geopoetry9) makes me wonder what Hoffmann would think of my depiction of the chemist as a scientifique déambulateur, a strolling scientist. (Aptly enough, Hoffmann was a migrant, too, when he left postwar Europe to reach the United States in 1949). In addition, Hoffmann emphasises that the fabric of chemistry is a networked universe of “hundreds of small[er] problems”, “puzzles”.
Charting paths, charting territories. This somewhat ‘topographic’ aspect of chemistry is the topic of one of Hoffmann’s poems, Theoretical Chemistry, which is inspired by the exploration of energy landscapes:
[…] You see, that thick lush growth stopped progress
here, but I could spot a road gathering
on the other side. That’s where we had to go.
[…]I saw tracks in and tried to follow them. But it didn’t work, bushes closed in, there was poison oak, vines with rows of sharp red thorns. I came back day after day, trying, tracing paths back
from the other side. For I knew a pattern, the right way, had to be there. In the end I found one, but what’s bothered me since is that I didn’t follow the paths that are hidden there, the way I should have, but
I hacked a rough piece of a new one through. The other day I met a friend who’s run into the same wild terrain. Starting out from a hill nearby, he found a different way. But I told you there was only one.
The converging trajectories of Hoffman’s poem can be contrasted with the diverging “two roads” of Robert Frost’s famous The Road Not Taken
TWO roads diverged in a yellow wood, And sorry I could not travel both And be one traveler, long I stood And looked down one as far as I could To where it bent in the undergrowth;
[…] I shall be telling this with a sigh Somewhere ages and ages hence: Two roads diverged in a wood, and I— I took the one less traveled by, And that has made all the difference.
From poetry to chemistry and back. The déambulation has come full circle.
2.Chemistry: The Impure Science, Bernadette Bensaude-Vincent and Jonathan Simon, Imperial College Press, 2012 (2nd edition).
3.From the Special Report: How dangerous is chemistry?, Nature, 2006, 441, 560-561 (doi:10.1038/441560a):’But what does seem clear is that academic labs are more dangerous than those in industry, with a more relaxed approach to safety.“We find that the accident rate [in universities] is 10 to 50 times greater than in the chemical industry,” says James Kaufman, president of the Laboratory Safety Institute in Natick, Massachusetts. “In DuPont, if a guy hits his thumb with a hammer in Singapore, the chairman of the board has a report on his desk,” he says. “Imagine if that happened in academia.”
“In industry we often say that we are surprised more people aren’t injured in academic labs,” agrees Derek Lowe, a research chemist who blogs on “In the pipeline” (http://www.corante.com/pipeline). “In universities, people are still learning, and people work all hours. If you are there alone at three in the morning, that’s seen as a good thing.”‘
4.My translation. The Italian text is quoted from Il segno del chimico, Einaudi. I have not cited the original German text because I have been unable to retrieve a copy of Levi’s edition of Gattermann’s textbook (Die Praxis des organischen Chemikers. Von L. Gattermann, bearbeitet von H. Wieland. 26. Auflage, 428 Seiten, mit 58 Abbildungen im Text. Verlag W. de Gruyter &Co., Berlin und Leipzig 1939).
7.Ruiz, Hector. 2014. La voix déterritorialise. Autour du recueil «Qui s’installe?». Conférence organisée par Figura, le Centre de recherche sur le texte et l’imaginaire. Montréal, Université de Montréal, 30 septembre 2014. Document audio. En ligne sur le site de l’Observatoire de l’imaginaire contemporain. . Consulté le 9 juillet 2016.
8.Gaston Bachelard, La poétique et l’espace, Gallimard, 1961. Bachelard is also well-known for his works on philosophy of science, especially philosophy of chemistry, a subject which he addressed notably in Le matérialisme rationnel, Presses Universitaires de France, 1972.
9.Rachel Bouvet, Vers une approche géopoétique, Presses de l’Université du Québec, 2015
Life is a process of becoming, a combination of states we have to go through. When people fail is that they wish to elect a state and remain in it. This is a kind of death.
Anaïs Nin, in D.H. Lawrence: An Unprofessional Study (and as found at the end of my PhD thesis)
I pulled over, and I thought about it. The wind was as cold as steel and sharp, invisible nails piercing through my hands, as I was filling the car up.
It was exactly then, as I was fiddling with the fuel dispenser at a filling station, that I thought about it once more.
We had been driving all over southern Wales, towards the setting sun, a race against the time, against a wild headwind, to see the sky blush orange and the sea swallow the remains of the day. The narrow road twisted up and down following the contour of the hills, a grey ribbon unfolding before us, a skin shed by an invisible snake, a trail for us to follow.
Directions, paths, cycles, and irreversible transformations. I thought about all of this as I sniffed the sweet organic smell of petrol. Harmful. Irresistible, like so many things in life. Like speed, and the fear and the thrill that go with it. What car racing is made of. Ayrton Senna once remarked that: “We are made of emotions, we are all looking for emotions, it’s only a question of finding the way to experience them. There are many different ways of experience them all. Perhaps one different thing, only that, one particular thing that Formula One can provide you, is that you know we are always expose to danger, danger of getting hurt, danger of dying“1.
Heat as a source of motion. Danger as the source of emotion.
I had enjoyed that long drive, allowing myself some fun with the last gearstick that my left hand would shift for quite a long time. A long straight dives down, then an uphill strech comes up as a sharp turn approaches: brake, change down and double-declutch -or, I’d better say as far as I’m concerned, do your best attempt at it-, steer, enter the corner, open the throttle again, and floor the pedal: it did not take much more than this to feel as close as ever to the world of car racing.
Something clicked and I stopped day-dreaming. The tank was full, petrol dripping from the nozzle of the fuel dispenser. Droplets drifted in the wind while falling down, and I felt for those lost hydrocarbons, lost and vaporised into the crisp air of an early spring day, somewhere in Wales.
And I thought about it once more.
I thought about entropy.
Illusions of stillness
Thermal engines, and their elegant profiles sketched on pressure-volume plots. It seems like yesterday, but it is a life ago. Secondary school, my brand-new driving licence in my wallet, and those long hours studying invisible gasses being compressed, expanding, at a frustratingly slow rate, for equilibrium to be attained.
Stillness. Only then does entropy remain unchanged.
My duel with thermodynamics continued at university. Fast-forward to those rainy days of November 2002 when the grey city was drenched, its underground was flooded, and its sewers were bursting at the seams. At first, I felt a mortal dread of that first-year physics course. The professor, a middle-aged stamp collector sporting a grey toothbrush moustache, relished the thought of inspiring terror in his students, and wielded his power in the most unlikely of ways, for examply by punishing students who mispronounced physicists’ names. You could easily fail an exam because of the tricky uy combination in the name Huygens.
Maybe that is why I ended up going to the Netherlands for my PhD. To learn to say “Huygens” the Dutch way. To visit the Provinces that could flourish during their Golden Age of tulips, trade and art. To see the canals criss-crossing Amsterdam. To meet the intense gaze of Vermeer’s Girl with a Pearl Earring, and taste the overripe fruits that defy time in Dutch still lives.
Quasistatic images, like those reversible processes.
No. I’m fooling myself. It’s nothing but an illusion. Even then, even when she was actually by my side, even on those tablecloths… entropy ruled supreme, as it always does. Loss, dissipation, and disorder. Look more closely: there’s always a fly on the cheese, or a bruise, a crack on the skin of the fruits. They’re about to rot.
Stillness does not befit a chemist, after all. Chemical equilibria, one of the defining features of our science, hide microscopic, frantically reversible transformations occurring at a blistering pace, all under the cover of a macroscopic invariance.
So, a chemist’s inner balance is dynamically stationary, reminiscent of what Tolstoj writes in The Death of Ivan Ilych: “He in his madness prays for storms and dreams that storms will bring him peace“.
The howling gale was sweeping the Welsh coast.
I drove off. I turned the ignition on.
Time to go, follow the fuel and its flow.
Dissipation and multiplicity
I have always regarded the Second Law of thermodynamics with a mixture of awe and distrust. I am aware that this law stands for something powerful and ubiquitous, but I have always believed that it is, in some respects, utterly incomprehensible at the same time. Part of this gut feeling probably boils down to the countless ways of expressing, defining, interpreting the law. If you want to discover more about the confusingly multifarious nature of the Second Law, the Web will provide loads of notes, course handouts, etc. : just have a look out there, for example on this page.
What most angered me was the concept of efficiency. Don’t laugh at me! For reasons that I struggle to explain, I have always felt for thermal engines, toiling and sweating and ticking over, only to convert into work just a fraction of the energy extracted from, say, petrol. Dissipation was inevitable, like a thermodynamic curse placed on engines, a fact of nature which, I firmly believed, was deeply unjust.
So, despite passing all my physical chemistry and physics exams with flying colours, I always felt profoundly uncomfortable with entropy and the Second Law until I attended the fourth-year course on statistical thermodynamics. Boltzmann’s formula changed my outlook. It reads like this:
S = kB ln W
where kB is Boltzmann’s constant and W stands for the number of microscopic states consistent with a given macroscopic state. How to understand this concept? Suppose you want to describe an ant colony: you can choose to approach this task at a macroscopic level (how big the mound is, its temperature…) or try and describe the colony on the basis of the position and the speed of each ant. The overall appearance of the ant colony will not change for countless equivalent sets of positions and speed of all the individual ants. Well, these equivalent sets are by far and large a good example of what W means.
(At any rate, note that here we encounter once more the micro/macro duality that pervades all chemistry).
Another autumn, another clash with thermodynamics, another tryst with the Girl with a Pearl Earring. It was the year 2005, and I was preparing for my first adventure abroad, the Erasmus exchange project at Leiden University. I remember slipping handouts on the conjugation of Dutch verbs into the pages of the reference textbook of that course, the venerable Fundamentals of Statistical and Thermal Physics, by Frederick Reif.
I remember defying entropy with her. Perhaps.
One day, the lecturer stopped halfway a sentence, stared at us and said: “This formula is carved on Boltzmann’s tombstone“.He paused for a while, as if had forgotten what he was to say. Then, he quipped, grinning proudly : “Physical chemists never die, they tend to the maximum entropy”.
Equilibrium as the maximum number of equivalent states. Electing one is a kind of death.
Ode to entropy
A few days ago, on a sleepless night, I found myself thinking about Boltzmann’s formula and those long-lost days at university.
I closed my eyes. My mind strayed as I was humming a tune…
…infinité de destins
on en pose un
qu’est-ce qu’on en retient?…
…an infinity of destinies
we set one aside
what remainder will we keep?
…entropy, entropy everywhere once more, entropy blowing sand across the desert and I was wondering what we keep, what we know, when we choose, take a turn, leave a path. I looked at my hands. I saw words as if tattoed on my skin.
“O my soul, do not aspire to infinite life, but exhaust the limits of the possible”.
The limits of the possible…like in racing, the limits of grip define how fast you can drive, how dangerously you can live. Listen to Ayrton Senna once more: “you think you have a limit. And you then go for this limit and you touch this limit, and you think, ‘Okay, this is the limit.’ As soon as you touch this limit, something happens and you suddenly can go a little bit further.” 1
Treading the fine line between grip and spin seems the price to pay to live life to the full. Like a ± sign, like the uncertainty of measurement, the secret lies in that blurry space, a shimmering haze surrounding our lives and defying all attempts to define them.
I thought about Boltzmann’s formula once more, and its being a special case of a more generic formulation of statistical entropy known as Shannon entropy related to information theory.
The higher the entropy of a state, the higher its probability, but also its microscopic randomness, which means that we know less about it. Yet, see it the other way: it is uncertainty that unlocks multiple possibilities, multiple equivalent states.
Not convinced? Take Boltzmann’s formula. S = 0 when W = 1. Indetermination disappears when there is no multiplicity, and then we know everything. Or maybe not, because we can reach S = 0 only without being alive to experience it. To put it bluntly, death is the only case when there is just one possible state. What a price to pay.
Well…”Electing one is a kind of death” once more, right?
So, Boltzmann’s formula can really come into its own in our everyday life, as this is not a dry mathematical expression, but something within grasp. For example, think about this interpretation: being alive, having in other words S ≠ 0, implies that there is more than one equivalent microstate. Well, I’d like to imagine that these microstates are the countless permutations and combinations of mood, thoughts, ideas that each of us experiences at a given moment in life.
In other words, we should stop despising entropy. Look it in the face: after all, entropy was coined from the Ancient Greek ἐντροπία, meaning “a turning towards”.
Yes, I hear you shrug and say: “Brilliant metaphors, a fine piece of writing, but in the end that’s just empty talk”. Fair enough. Yes, entropy may well be a spell cast on us, and yet everything changes when we make most of it, when we acknowledge and harness it. Now, the key question is, how to attain an equilibrium embodying the maximum multiplicity of accessible lives at a given moment? At the same time, how to make sense of and shoulder the ever heavier burden of the alternative routes that we have not followed, of all the paths left behind at the many crossroads, along the arrow of time?
We need to talk about chemistry
In my realms of chemical fantasies, I imagine that the arrow of time can put on peculiar disguise, such as the extent of reaction or the reaction coordinate, turning into transforming matter and space, respectively.
The extent of reaction is, as defined by the IUPAC Gold Book, an “extensive quantity describing the progress of a chemical reaction equal to the number of chemical transformations, as indicated by the reaction equation on a molecular scale, divided by the Avogadro constant (it is essentially the amount of chemical transformations)”.
So, if you take it word by word, the extent of reaction, indicated by the graceful letter ξ, is nothing but the amount of stuff being transformed, corrected by the stoichiometric coefficient (“as indicated by the reaction equation on a molecular scale”), and expressed in moles. Why am I talking about ξ ? Simply because it will unlock yet another reincarnation of the infamous Second Law, which sneaks in and determines the conditions for chemical equilibrium, and the direction of chemical reactions.
To understand this, we need to face the so-called Gibbs free energy, G, something that is dearly beloved by chemists. A lightning sketch of what it means? Take a battery, any battery, and read its voltage. Guess what? You are looking at a masked form of G.
For those who prefer the nuts and bolts, G packs up in a neat way all sorts of variables that can come into play in chemical transformations. Its definiton is:
G = H – TS
where H is the enthalpy, T the (absolute) temperature, and S our dear entropy. So far, so good, all like in a textbook. What I would like to point out is this:
entropy always matters, unless the temperature is zero.
entropy is not the only thing that matters, when talking about free energy…
…but entropy is to be inteded as entropy of the chemical system, so an “internal” state function of the system, while enthalpy is transferrable, energy exchanged with the surroundings.
Chemical reactions and their inner entropy, along with another form of energy that impacts what surrounds us. The randomness within together with the energy that we can share with those who are closest to us.
Chemistry can be so close to the human scale.
Unveiling what G really depends on is a good way of understanding free energy: pressure, temperature, and number of molecules are its natural variables. Let us focus on the latter, because it is, arguably, the ‘most chemical’ of the three. If we forget about the first two variables, keeping them constant (or making the assumption that they shall be), we start to understand why the extent of reaction ξ comes into play. We can imagine that ξ is like a dial letting us play with the concentration of reactants and reagents of a certain chemical reaction, changing their amount, which means moving the reaction forwards and backwards, and so time, at least in our thought experiment. G will respond accordingly: think about the focussing knob of binoculars, there will be a position giving the sharpest focus, while turning left and right will both give an unfocussed image.
Focussing means turning the knob until we reach the minimum blur.
Equilibrium means tuning ξ until we reach the minimum G.
This change in G as a function of ξ (the partial derivative of G with respect to ξ) is the free energy of reaction (watch out for the subscript r) which is accounted for by comparing free energies of products and reactants. This equals zero at equilibrium.
Let’s sum it up with a bit of maths and graphs:
Look at that last equation: ΔrH = TΔrS. Chemical equilibrium, the condition where the inner and outward energy associated with the chemical reaction are evenly balanced, without necessarily being equal to zero.
A dynamic levelling out of our randomness within, and the warmth that we give -or take.
Moreover, do not forget that we have set the composition of reactants and products by choosing the value of the extent of reaction minimising G. Is the chemical equilibrium then a boring stasis? Not really: two-way chemical transformations continue frantically and you can imagine that it is this ease of mutual interconversion of products into reactants and viceversa that embodies the “maximum randomness” corresponding to the minimum G. If we start from the reactant A, we can claim a much more detailed knowledge of what is in our flask than at equilibrium, when the molecules of A and B keep changing identity, despite being in macroscopically fixed proportions (set by the extent of reaction, which is the equilibrium constant in disguise).
Could chemistry be the most unlikely signpost of a dynamic peace, a waymark to happiness?
Shedding the old colours
Chemical equilibria are achieved through chemical transformations, and there is no better time of the year to talk about this topic than spring, the season of changes, of renewal. If life had a birthday, that would fall sometime in April. Yes, Eliot’s infamous “cruellest month”4, which turns wonderful when the “increase of the density of lived time may be found in those days of alternating sun and rain, […], when plants grow, almost visibly, several millimetres or centimetres a day. These hours of spectacular growth and accumulation are incommensurate with the winter hours when the seed lies inert in the earth” 5. The time of the year when birds migrate north, and wear their brightest plumage. They moult.
So does this blog: it sheds its worn winter feathers, sporting this new theme, and a new header image. Let me stop to acknowledge the work of a dear friend, fellow blogger, who took up the daunting challenge of turning my fuzzy ideas into a picture. Thanks ever so much, M.
This change accompanies yet another metamorphosis, another transition, a sudden gust of wind that makes my own flickering flame tremble and shake.
Like the atoms in a transition state…
…it was as I was listening to a song by the Italian band Baustelle that I thought about thermodynamics once more, on a sleepless night. Its title is La natura, (“Nature”), and the lyrics say it all:
L’unico modo per mostrare a tutti la felicità.
E’ la metamorfosi, la sola possibilità.
Ne sono sicura, muove la natura e la biologia
There’s just a single way of letting them all see
Only a metamorphosis will show how happy you can be
That’s a fact of nature of biology I can’t be wrong.
At a first glance, chemical reactions seem to imply that it is the outcome of the metamorphosis that matters the most. Beginning and end, products and reactants: what we had before and what we have in our flasks now; what we used to be and what we will be.
However, as my road trip in Wales taught me, with the many lengthy detours we had to take, there are countless paths between two given points.
Charting the course
Here we finally encounter the other form of (as I see it) chemical arrow of time, the reaction coordinate, which, by far and large, has a geometric meaning, along with my suggestion to interpret it as disguised time. The reaction coordinate represents the change in a chosen geometric feature of a reacting molecule (say, the distance between two atoms, or the angle between them) which can be a proxy for the progress of the reaction. In a sense, the extent of reaction was a reaction coordinate of sorts, referring to reacting stuff, and not geometry. Also, we note the macro/micro distinction again: the reaction coordinate is much more on a microscopic scale than the extent of reaction, which is rather an accounting tool to keep track of the amount of transforming matter.
Now, our discussion of G taught us that free energy plays a key role in chemistry, and all the more so when talking about reaction pathways, the trajectories of transformations. Say that the hydrogen molecule H-H is falling apart: we can imagine that H on the left and H on the right start to move farther and farther until they become loose. It takes energy to do so, and this “effort”, expressed in the form of free energy, can be plotted as a function of the distance between H and H.
At the top you will encounter the transition state.
Reaction energy diagrams are not restricted to this classical xy plane of textbook plots: reaction coordinates can be more than one, giving rise to geometric hypersurfaces. Take the molecule H-H again, and imagine mishandling it in all possible ways, by pulling, twisting, bending the poor thing as you try to break it apart.The transition state is by definition at the top of saddle points. This precise localisation also comes in with a well-defined configuration and a 50-50 of forming the reactants or the products of a reaction.
Too neat, too clear. I had rather talk about activated complexes instead. It takes energy to get there, to reach those fleeting arrangements hovering close to the highest point of the trajectory which transforms reactants into products. Life is on the edge up there, but what a scenery one can admire! On top of that, one must have a head for heights to be an activated complex, teetering on the brink of a headlong fall backwards, or poised to plunge forward at a breakneck speed. You must be a hybrid of past and present, an entity without clear identity. I quote this beautiful, almost lyrical description from Wikipedia: “in other words, [the activated complex] refers to a collection of intermediate structures in a chemical reaction that persist while bonds are breaking and new bonds are forming. It therefore represents not one defined state, but rather a range of transient configurations that a collection of atoms passes through in between clearly defined products and reactants.”
Steer your reaction course, your racing line, the direction followed by the metamorphosis, climb the uphill stretch to the saddle point, become an activated complex, and then stop at the top of the pass, and enjoy the commanding view onto your energy landscape. Feel the wistful nostalgia for the reactant state left behind, be tempted by the descent backwards, yield to it, or dive down and cross the barrier into an unchartered territory,into the unexplored coordinates on the contour map…
La trajectoire de la course
Et ton message à la Grande Ourse
Un instantané de velours
Même s’il ne sert à rien
The trajectory of the race
and your message to the space
the sweetest picture we can take
though meaningless at all.
The path to the products may well follow a single course, and yet all other trajectories will combine, and plot your graph.
And entropy will account for all the lines that part.
Footnotes & Acknowledgements
V.B. is gratefully acknowledged for the featured image, and B.P. for the photograph closing the post.
Das ist die Sehnsucht: wohnen im Gewoge
und keine Heimat haben in der Zeit.
That’s the emotion: living in the motion
and having no still space in time.
Motto, Rainer Maria Rilke (from Früher Gedichte, and my own free translation).
The time in the lab is a space full of gaps. Experiments can be long and tiring, or short and sadly unsuccessful, but there is always that odd operation that requires waiting: during setup, or measurements, empty spaces open up before us, like potholes, or sinkholes. It’s up to us to decide how to fill them. One could easily get trapped, for example falling prey to that irresistible urge to have a look at their phones, sinking deeper and deeper into a whirlpool that drags us swirling around.
Yes, I often waste my time like this, too, but when I resist this temptation, I enjoy letting my mind wander, and wonder, unbridled and free. Letting myself drift away on a stream of random musings, images, flashes of memory, all wildly chasing one another in haphazard combinations. You bob in a sea of constantly changing currents, and the roof of the building you can see from the window becomes the jagged profile of a turreted castle wall. Losing myself in reveries halfway an experiment, when the alertness can be safely switched to standby mode for a while: what sheer pleasure! How many wacky ideas have flashed through my brain in the midst of this carefree state of mental frolicking! So much so that if I ever became group leader – something that, at the moment, looks like a pie in the sky that I won’t bake any time soon – I would encourage this useless daydreaming. I’ll be honest: I would even go so far as to forbid earphones and headsets in the laboratory. If researchers and students complained, I would mention that there seems to be evidence that the brain is geared to losing focus constructively1. Put the brain into neutral and the engine will enjoy taking a rest from driving. Another example? The positive effect of purposeless walking, as discussed in this article regretting the waning popularity of this useless pastime.
There’s another thing I would do as a group leader. The opening quote of this post is from a poem by Rilke that is painted on a wall in Leiden. Muurgedichten, wall poems, a gorgeous idea. You walk the alleyways the bridges the canals, and lines and verses are thrown at you, suddenly, from above. Original versions, sometimes with an English translation. The gaze leaves the level of the ground. Words rhythms rhymes take you away from the flat horizon of our daily chores.
I would ask the other group members to pick their favourite poem, and share it by posting it onto the walls of the laboratory, or elsewhere. No songs allowed, because they are two-legged animals standing on words and music: their lyrics will always sound maimed. Poems only: these fragile constructions striking a balance between the inner musicality of their texture and the need to convey meaning.
Here’s the question: can you write poetry while working in the laboratory? No. Not because experiments need your full attention. A truism, and too easy an answer. The real reason lies well deeper than this, and it may look elusive at first because poetry and scientific research are of the same stuff that all enquiry, or quest, is made on – “Well, here he goes again with his long tirades give me the remote control please to switch him off…” I hear you say. But I am not asking you to believe what I say. Instead, listen to someone who spent her life with pens and poems.
“[…]It’s not accidental that film biographies of great scientists and artists are produced in droves. The more ambitious directors seek to reproduce convincingly the creative process that led to important scientific discoveries or the emergence of a masterpiece. And one can depict certain kinds of scientific labor with some success. Laboratories, sundry instruments, elaborate machinery brought to life: such scenes may hold the audience’s interest for a while. And those moments of uncertainty – will the experiment, conducted for the thousandth time with some tiny modification, finally yield the desired result? – can be quite dramatic[…]”
“[…]But poets are the worst. Their work is hopelessly unphotogenic. Someone sits at a table or lies on a sofa while staring motionless at a wall or ceiling. Once in a while this person writes down seven lines only to cross out one of them fifteen minutes later, and then another hour passes, during which nothing happens … Who could stand to watch this kind of thing?[…]”
Looking at the notes from my recent ‘narrative and storytelling’ course, well, I can but agree with her. No pace, no (visible) daunting challenge to overcome, no real plot. A no-go.
Anyway, it is what Szymborska says later that matters most.
“[…]inspiration is not the exclusive privilege of poets or artists generally. There is, has been, and will always be a certain group of people whom inspiration visits. It’s made up of all those who’ve consciously chosen their calling and do their job with love and imagination. It may include doctors, teachers, gardeners – and I could list a hundred more professions. Their work becomes one continuous adventure as long as they manage to keep discovering new challenges in it. Difficulties and setbacks never quell their curiosity. A swarm of new questions emerges from every problem they solve. Whatever inspiration is, it’s born from a continuous “I don’t know”.[…]”
Yes, and I would add, love is built on these unsteady foundations, too. A common ground full of “I don’t know”, of “we don’t know”. Szymborska continues by taking us to the source shared by research and poetry:
“[…]This is why I value that little phrase “I don’t know” so highly. It’s small, but it flies on mighty wings. It expands our lives to include the spaces within us as well as those outer expanses in which our tiny Earth hangs suspended. If Isaac Newton had never said to himself “I don’t know,” the apples in his little orchard might have dropped to the ground like hailstones and at best he would have stooped to pick them up and gobble them with gusto. Had my compatriot Marie Sklodowska-Curie never said to herself “I don’t know”, she probably would have wound up teaching chemistry at some private high school for young ladies from good families, and would have ended her days performing this otherwise perfectly respectable job. But she kept on saying “I don’t know,” and these words led her, not just once but twice, to Stockholm, where restless, questing spirits are occasionally rewarded with the Nobel Prize.[…]”
It is the one and only driving force. Genuine scientists, like genuine poets, as Szymborska remarks, “must also keep repeating “I don’t know”.” Yet, I believe, two diverging trajectories of inspirations take off from the same driving force: the inspiration of the wandering mind for the poet, the inspiration of the busy hand for the chemist. Yes, mind-vs-body is a fictitious duality, but as far as inspiration is concerned, it is very real. You cannot have them both in the same place. Such is the price to pay for facing the unknown.
Two sides of the same coin
To explain this, let me take what Szymborska says and flesh it out with my own words. Inspiration, for me, is a voice saying: “I don’t know, but now I feel I know“. It is a vibration. A resonance. You feel it , and you don’t know where this wave will take you. “I don’t know, but now I feel I know”. It is a special singularity that rips the fabric of space-time creating a white hole -and I am knowingly mentioning this technical term from general relativity. Spaces of decreasing entropy in the exciting turmoil shaking all matter, white holes are singular instants shining with escaping light. It is in this dazzling flow of information that the wandering mind, or the working hand, feel their own special resonance emerging. The poetic inspiration and its scientific counterpart share the same astonishing unpredictability. The same coin, yet with two sides. Here is the key point.
Poetic inspiration resembles the act of finding ways to write resonant chemical structures of a certain compound that, at a first glance, defies all attempts to rationalise its properties. Suddenly, you spot possible resonance structures as if you were fishing them out of a rough sea teeming with nonexistent, yet plausible, entities and you lay them bare on paper. Taken together, these resonance structures are like moulds of what would otherwise remain unsaid, allowing the poet to cast verses from blurred shapes blinking their light amidst a chaotic flow. This poetic inspiration seems to combine quickness, visibility and multiplicity, in terms of Italo Calvino’s literary ‘values’ (from Six Memos for the Next Millennium). Quickness, because one needs to catch sight of the elusive silhouettes before they disappear; visibility, because the poet’s representation in words must be clear-cut, though not necessarily unambiguous, hence the multiplicity.
Instead, chemical inspiration is much more similar to a hand shifting its position up and down on the fingerboard of a stringed instrument: it senses that there is a special vibration that will resonate if a string is pressed in the correct position, and so the fingers will feel their way and try. It involves finding the right pitch, and playing the note that the instrument was already primed to sing. I would say we can recognise exactitude first and foremost, and lightness of touch to avoid upsetting the temperamental system under investigation. The sixth missing value (Calvino died before finishing his lectures), consistency, would have completed the triplet defining chemical inspiration.
As a conclusion, this fundamental difference between the poet’s and the chemist’s inspiration explains why, in my view, the cliché of the poète maudit (accursed poet), or the dejected artist creating stunning masterpieces from sheer desperation does not apply to the chemist. Creativity in the chemical laboratory rests on the alertness that allows one to merge into the flow of information streaming from experiments. Serenity is the key to serendipity: a sense of harmony with the microcosm in our glassware is instrumental in perceiving the resonance that poises the chemist for that special inspiration.
The time of loss
The end of all inspiration is a separation of sorts. A loss. Written words stitched together into a frail shell encasing the emptiness within. Visible operations that conceal the impossibility to touch those invisible entities that seemed within reach.
That reminds me of another poem from Leiden’s walls, Loss, by the Syrian poet Adonis (translation retrieved here).
؛والضياعُ يوحِّدنا بسوانا والضياعُ يعلّق وجه البحارْ برؤانا والضياعُ انتظارْ.
Loss unifies us with something other than us. and loss fastens the face of the sea to our dreaming.
And loss is just waiting.
This loss is what sparks that quest, Szymborska’s motto again.
“I don’t know.”
Leaving a place is a kind of loss, too. I will soon fly away, pack my luggage, and leave this lab. Another city, another country. Lots of poems in my bag.
So, after all, it is not so surprising that an powerful inner voice has told me to look for those lines by Kavafis, to read them once more, to learn them by heart. This time, however, in the original version. As if I wanted to swallow the printed page and eat it to let those words become part of me, never to forget them again; as if I wanted to challenge them, because there will be a new city, a new life, a new place, even amongst the debris that strew my inner space, so ravaged a country, so forlorn a city. I recite them aloud as if I wanted to cast a spell on me, on the life that I am leaving behind. Still another voice questions me in its mocking tone uttering those two syllables that hurt like wild lashes: “You said”, Είπες· . The voice keeps reminding me and I, relentlessly, I will always retort:
Μια πόλις άλλη θα βρεθεί καλλίτερη από αυτή.
Μια χώρα άλλη θα βρεθεί καλλίτερη από αυτή.
Another city will be, better than this. Another country will be, better than this.
Better than this, where so much was laid waste, so much was lost, so much could have been but is no more. Like in the aftermath of a runaway reaction.
And still I will deeply miss those eyes who have seen me through this landscape of destruction. The rarest diamonds in a charred coalmine.
“[…] La Cuisine moderne est une espece de Chymie. La science du Cuisinier consiste aujourd’hui à décomposer, à faire digérer & à quintessencier des viandes, à tirer des sucs nourrissans & pourtant legers, à les mêler & les confondre ensemble, de façon que rien ne domine et que tout se fasse sentir; enfin à leur donner cette union que les Peintres donnent aux couleurs, & à les rendre si homogenes, que de leurs differentes saveurs il ne résulte qu’un goût fin & piquant, & si je l’ose dire, une harmonie de tous les goûts réunis ensemble […]”
“Modern Cuisine is a sort of Chemistry. Today, the Cook’s science consists of decomposing, digesting and refining meat, of drawing nutritious and yet light juices, mixing and combining them together so that nothing could predominate and that everything could be tasted; finally, this science also brings these ingredients together in the same way as Painters do with colours, making them so homogeneous that the different flavours will turn into a fine, attractive ensemble, and, if I dare say it, a whole harmony of all flavours blended together”
Les Dons de Comus, ou les Délices de la table, François Marin, 1739, pages XX-XXI (the original ortography has been retained in the quoted passage).
“It could be your next blog post”, said P., a colleague of mine, “you could write about the stages of sugar syrup”. Vaste programme1, I would say during a bout of Francophilia…
Now, I’m definitely ready to take up my colleague’s challenge, but an entire blog post on syrup stages could simply taste too sweet for readers to eat. Besides, I know myself all too well: like a frantic honeybee, I will invariably end up flying from flower to flower collecting all nectar that I fancy: dwelling on a single subject does not really suit me, honestly.
That said, let’s start our sticky journey: get ready to wade through thick syrupy swamps and experience some of the hottest environments on Earth -or, maybe, just in the kitchen. What a timely moment to start exploring the universe of confectionery: the festive season is well behind us and some sweet thoughts will help to see us through the late-winter blues.
Spinning threads of words and sugar
When I first met the English confectionery, two similar Italian words came to my mind: a carefully-made wrapping or packaging (confezione) and the candied almond known as confetto. If one looks at etymologies, confectionery and its Italian soundalikes do share a common origin. Confetto, for example, stems from the Latin confectu, the past participle of conficere, meaning ‘to make, to prepare, to consume’, exactly like to confect, confection, and confectionery. Indeed, confezione as confectionery is attested in the Italian language, though with an archaic flavour, and both languages seem to use the very same word to indicate both a type of sweet and a medicinal preparation, usually coated in sugar. The latter was somewhat predominant in the Middle Ages, when table sugar was virtually only used in medicine, and this sweet powder from faraway lands would be stocked alongside expensive spices at the apothecary’s2. And, incidentally, early chemistry did take on board time-honoured pharmaceutical lore and ‘laboratory practices’3. (However this does not justify the confusing British use of chemist for shop, or person, where medicinal drugs are sold. This is something that the Royal Society of Chemistry itself has stressed in its report on the 2015 survey on public attitudes to chemistry).
Cracking the candy
Back to confectionery, this is a veritable galaxy in its own terms within the universe of food and cooking. When trying to make sense of the mind-blowing variety of confectioneries, a chemical mindset comes in extremely handy. That’s because, as philosophers remind us3,4, chemistry is a hybrid science with a good dose of taxonomy in it: like it or not, chemists have always had to deal with – and classify-the multifarious nature of the material world. Classification, however, is not important only for its own sake: the act of arranging chemical entities can beget chemical laws, as exemplified by periodicity. So, while we navigate confectionery, how can we come up with a taxonomy or an ordering principle of sorts? It would be great to explore the kitchen with the same scope and vision of Linnaeus, but that’s not what blog posts are meant to be (and mine are already quite lengthy). More simply, let’s break down the components of a confectionery product:
A candy, like many other edible things, is similar to a building. Sugars, and the way the cook handles them by controlling the temperature they reach during cooking, turn into crumbly wattle, solid bricks, or hard stones. Additional ingredients (if any) can help make sure that the building will have the texture that the cook and the eater desire, playing the role of concrete, mortar, daub, steel rods…Finally, add extras to taste, much as one would paint, decorate or plaster a wall.
So, when it comes to classifying candies, it is useful in the first place to address each of these three components in a sequential way, along with other specs of the recipe:
-relative proportion of sugars -when and how the syrup is mixed to the scaffolds -when and how inclusions are added
Beside these two triplets, the cooling of the reaction mixture is often even more important than all preceding steps, determining to a large extent the success or the failure of the synthesis, er, the recipe. This is where chemistry comes into its own: a cooling candy-to-be is undergoing crystallisation, a fascinating chemical process and a tricky practical operation at the same time.
Swirl down, sweet snow
How many times, when trudging through the white icing on winter’s cake, have you thought: ‘it’s crunching like sugar beneath my feet’? And, caught in a flurry of swirling snow, have you ever likened it to a sprinkle of powdered sugar?
If so, you’re a poet.
From the opening lines of La primavera hitleriana (‘The Hitler Spring’) by Italian poet Eugenio Montale…
Folta la nuvola bianca delle falene impazzite turbina intorno agli scialbi fanali e sulle spallette, stende a terra una coltre su cui scricchia come su zucchero il piede[…]
The thick white cloud of crazy moths is whirling
around the pale lights and the parapets
spreading a blanket on the earth that snaps
like sugar underfoot[…]5
Poetry aside, thinking about snow is a useful starting point to get to grips with sugar crystallisation. Three general facts will come in handy later:
When it’s too warm, it never snows but it pours.
When it’s cold enough, it all begins with a seed.
Wet, fine, frozen, heavy: many words to say snow.
Now, of course, do bear in mind that snow is an example of change of state of matter, while sugar crystallisation involves a solute (sugar) in a solvent (water) that clusters into precipitating (falling) crystals (solids). Both these phenomena, however, show common features.
A dance in three movements
With the help of my favourite food bible6, let’s take on sweet crystals. Looking back at the bullet list written above:
1 ) Let’s start from room temperature. When a big lump of sugar is added to water, (which is the first step of both recipes I will be talking about below), only some of it dissolves. That’s because room temperature is a slow microscopic waltz, and only when we crank up the cooker does the tempo change and quicken: water will then lead more and more sugar into a reeling dance, and the solid is dragged in this invisible, warming whirlpool.
Eventually, this solution will start boiling, not at the same temperature of sugar-free water, but higher, because of the dissolved sugar. How come? Well, think about this: sugar and water love each other. A lot. They make perfect dancing partners, but theirs is also one of those all-consuming, mutually absorbing passions. It takes brute force to separate water from its sweet companion, more than it would be required to separate water from water. Yet, heat is a ruthlessly efficient kidnapper, and more and more water is eventually lost into the air. So, the more we heat, the stickier the situation becomes, because there will be a larger and larger excess of sugar molecules which will not find an aqueous partner, creating a syrup. They tightly cling onto any remaining water, frantically scrambling around in an ever-accelerating chaotic dance, and so heat needs to become increasingly brutal: a thermometer will show that the boiling temperature will keep on creeping up as one continues to heat the syrup.
What does this mean? The longer one boils the syrup (or the higher the temperature reached), the lower its water content. Less water means a harder final product. Bear this in mind. Rule of thumb number one of the art of confectionery.
Without the company of enough water, there could be a way out for desperate, forsaken sugars: meet and cling onto one another, sinking back into a solid. But the heat keeps them apart in a violent motion, bouncing around and so sugars cannot get hold of one another. All it takes for a crystal to form is a slower rhythm – a drop in temperature – and some sort of trigger . Think of the sugar syrup as a boulder teetering on the brink: it just takes a light push to make it fall.
2 ) So, this concentrated hot syrup is primed to form sugar crystals: when the dance slows down and something helps sugars to bump into one another, a crystal will start growing. That’s why we talk about nucleation and growth when discussing crystallisation. These words sound dry and technical, but they can also tell the story of the most bittersweet flavour of life, stories of random encounters (nucleation) turning into ever more passionate love (growth). We love, and so do molecules, in their own way. The trigger, the nucleus, can be a minute crystal that has already formed, or even a foreign body, like some dust. Then, growing crystals vie with each other for the limited available sugar much as snow crystals do in clouds. It is at this stage that the cooling syrup requires the cook’s full attention.
3 ) That is because sugar crystals can grow to different sizes and shapes, much like snowflakes. So, although crystallisation is indeed ‘order out of disorder’, order itself can come in different versions. Think about boxes: either you stack them up in a single tall pile reaching to the ceiling, or you stack them in pairs but all over the floor.
So we have two main options: large but few, and small but many. What do they mean in terms of candy making?
Big is not beautiful
The hot syrup is a chaotic environment, every forsaken sugar cries and shouts and tries to draw their fellows’ attention, all of this while swirling wildly around. What a dramatic scene! It’s an unruly mob looking for a charismatic leader. Imagine that all of a sudden a voice resonates piercing through the hubbub: it speaks the loudest, it will be heard. The seed of unrest moves swiftly in the heated syrup, and quickly rallies supporters all around. No time for other groups to form: they are dispersed in the crowd. The mob clusters around its leader, ready to follow down that road, the road to crystallisation.
Big crystals form this way, when few seeds collect lots of sugar molecules, often as a result of the crystallisation starting too early when the syrup is still too hot. They contribute to a coarse, grainy texture in the candy, and feel chunky in the mouth. How to avoid them?
Call in the riot police
It looks like that the most finely-textured candy is similar to a pluralistic society: many little crystals all coexisting like many political activists voicing their opinion and gathering small groups of followers. It is (Zygmunt Bauman would approve of it) a fluid society.
All we need to do is to wait for the tempers to cool down, and then stir up some healthy agitation, slowly but continuously, to encourage the engagement of as many seeds as possible.
If a stirring stick is not enough, well, plan B is to draw the baton. So, another way to make sure that law and order reigns in the syrup is to rely on something that will forcefully prevent clustering.
Cooks have used additives to limit crystallisation, in jargon called ‘doctoring agents’, for a long time. They make sure that police cordons are thrown throughout the syrup preventing the clusters of people from growing. Crowd control in the kitchen.
If trained people can control other people’s unrest, sugars can control the crystallisation of sugars. Take note: this is a very important concept. Difficult to understand? Not really.
An exercise with dumbbells
Our everyday life is full of examples of activities involving packing, arranging, ordering things. Someone is tidier, someone is messier (like me): but if the form of the object to be packed does not help, well, it is a no-go. Sugar crystallisation in candy making, invisible though it is, provides just another example of it. How could you turn packing into a nightmare? Simply by adding a handful of oddly shaped items. Believe it or not, it is just the same for ‘doctoring agents’ in confectionery.
Table sugar is sucrose. It looks like a fixed-weight dumbbell with two equal weights, but of different colours. We call one half of it fructose, the other glucose.
So, because you have got two units, you can name sucrose a dimer. Say you are at the gym, and your have got to tidy dumbbells up, arranging them back on the rack. As long as the dumbbell is in one piece, that is piece of cake. But if the handle breaks and the two weights fall down, well, that is another cup of tea. Imagine that enough handles break, or that there are more weights than handles, and this is a recipe for disaster: you will never be able to fill the dumbbell rack. Game over.
Controlling crystallisation in candies rests on either of those two options: have more weights than handles, or snapping the handles to separate the two ways. The former just involves tweaking the sugar proportions, replacing some sucrose with glucose, for example. But chemistry is dead good at snapping handles, at breaking bonds: we will see later how to do this.
Right, enough theory and taxidermy of confectionery for now: let’s talk about the real stuff. Here are two sweet case-studies that have made me sweat and swear in the kitchen in the last few months: lokum (aka ‘Turkish Delights’) and torrone (hard nougat).
The same and not the same
Different as they might seem, chewy pink cubes versus rock hard white slabs, lokum and torrone come to the same critical crossroads: the mixing of hot syrup with the chosen scaffold halfway through the recipe. And both rely on some sleight of hand to avoid unwanted, untimely crystallisation.
Looking more closely6, here are a few differences:
It is an aerated candy, or, put it differently, a toughened egg white foam (a reinforced meringue): the most important step in its preparation involves streaming hot syrup into whipped egg white, while whisking.
Sounds easy? Maybe, but if you want to nail it, not only do you have to get the timing of the mixing right, you must also have a feeling for the intensity of the whisking motion. All of this while the white-hot egg+syrup goo gets splattered all over the kitchen. (See the picture at the start of this post. Like in the lab, safety first: wearing protective spectacles when working with syrup is a golden rule). At any rate, what matters from a chemical perspective is that nougat could be called candied protein: after all, this is what egg white is made of.
It belongs to the family of jelly candies: their chewy bite is determined by the added scaffolding. Cooks can choose between a variety of ingredients, many of them now widely available in supermarkets, too: agar (from algae), pectin (from fruit) and starch. Lokum relies on the latter, in the form of the humble cornflour.
Watch out: starch is a massively heavy counterpart of the sucrose/dumbbell that we talked about before. Individual weights can be stacked one on top of each other, or arranged in more convoluted ways. Whichever you choose, remember that sucrose was a di-mer a two-unit dumbbell. Starch is a poly-mer a multi-unit object, and losing sweetness is the price to pay when going from one to many. Sucrose was a two-colour dumbbell, with glucose and fructose as weights; instead, starch just contains glucose units. Just to crack the jargon, because we are talking about sugars, we can also say that starch is a poly-saccharide, which in plain English would sound like multi-sugar. So, if I called (tongue in cheek) nougat candied protein, let me say that lokum is candied multi-sugar, which is slightly scary in these days of low-carb hype.
To sum it up, have a look at this flow-chart showing the main steps in the preparation of lokum and torrone
I turned out the first batch of lokum one Sunday morning. This time, I decided to have a go at making lokum after reading a review on the production of these sweets7, something that sounds like what we often do in the lab: you come across a paper, an idea flashes, and off you go.
[…]The history of lokum dates back to more than 300 years, making it one of the oldest sweets in the world. Turkish legend has it that in his endeavor to cope with all his mistresses, a Turkish sultan summoned all his confectionery experts and ordered them to produce a unique dessert to add to the collection of the secret recipes for which he was famous. As a result of extensive research lokum was born. In 1776, during the reign of Sultan Abdul Hamid I, Hadji Bekir, a fully apprenticed confectioner, arrived in Istanbul from a small town in Anatolia. Bekir set up a little shop in the center of the city, and quickly won fame and fortune among the people. Fashionable ladies began to give lokum to their friends in special lace handkerchiefs. […] Lokum had been known in Anatolia since the 15th century, but it had become widespread in the borders of the Ottoman Empire[…]7
Fascinating. Let’s have a look at how to make lokum using our scheme
sucrose (table sugar)
Cook syrup to…
How to add the scaffolding?
When to add the inclusions?
-Dissolve cornstarch in water.
-Add to hot syrup while stirring.
-Continue cooking until the mixture stops giving off steam.
Last step before cooling down
There’s one ingredient missing, and I left it out from the list on purpose. It is the famous ‘doctoring agent’ we were talking about before. To limit crystallisation in lokum, the sucrose-dumbbell is broken up by some lemon juice, or anything edible that has an acidic pH.
Sawing a dumbbell up into two pieces is not exactly the easiest pastime. Yes, it depends on how thick the handle is, but if your saw is not sharp enough, you will have to toil anyway. What about your own strength, then? Are your arms fit enough for the job?
As one can see, there is an interplay of three parameters to work out how efficiently we can break those blessed miniature dumbbells called sucrose. Let’s wrap it up:
How thick the handle is, in chemical terms, how sturdy the bond between glucose and fructose is. It turns out that it is not so frail as it might look.
How sharp the saw is: reactions happen, or not. Or we can make it happen, think about what we found out in the previous post about catalytic converters. Catalysis plays a role in making lokum, too: not only is the acidic pH of lemon juice a sharp saw, it also helps to corrode the handle, to slacken the bond.
How strong your arm is: cooks have an advantage over lumberjacks: they can crank the heat up, which is what they do when the syrup is being cooked. Heat, the water “kidnapper” is also a powerful source of energy for chemical reactions to happen.
Despite the heat, the lemon juice, the amount of sucrose broken up is ridiculously small. Yet, it is enough to avoid untimely crystallisation: after all, lokum contains also a very effective scaffolding agent, starch.
Following the recipe step by step, I boiled the syrup, then I added the starch mixture, and kept on stirring while heating. A glossy, viscous mass was formed, and it started clinging onto the silicone spatula. Call it goo if you like, but this was beautiful in its own way.
Finally, I added the extra bits, some rose water and beetroot extract. Then, I poured the pinkish mixture into a baking tray and I let it cool down. As a last step, I chopped it up into small pieces with scissors (that seemed to be the smartest idea).
I asked a Turkish colleague to taste my lokum: she said that it was a good attempt, and, tastewise, it was close to the real thing. Unfortunately the texture was off the mark, too soft. A couple of days later she brought lokum back from Turkey, an ideal basis for comparison. See for yourself.
My error? The maximum temperature reached by the syrup during the cooking step. My kitchen journal provides irrefutable evidence of my mistake: the recipe that I followed did not mention the temperature and I just tried to make an educated guess: 118°C Only later did I find out8 that I should have heated the syrup up to…126-127 °C.
Torrone (hard nougat) is quite another cup of tea. I decided to make it because I felt homesick, back in December: this month sees the consumption of torrone skyrocket, and not only because of Christmas. In some parts of Italy, for example in the north-east, children get presents and sweet treats on St. Lucy’s Day (13th December).
When I found the recipe in a book 8, I could not resist the temptation: the fact that the text classified it as ‘difficult’, just provided some extra thrill. After all, “if there’s a will, there’s a way”, right? Here are the proportions and the operations, from the same recipe:
sucrose (680 g)
honey (510 g)
corn syrup (170 g)
whipped egg white
orange blossom water
Cook syrup to…
How to add the scaffolding?
When to add the inclusions?
-Stream hot syrup into whipped egg white while whisking.
-Keep on whisking for a few minutes.
-Keep them warm in the oven.
-Add to egg white + syrup mixture as last step.
This time, the ‘doctoring agent’ is corn syrup, also known as glucose syrup: it is a crystal-clear, thick fluid containing free glucose, which is one of the two components of sucrose, in a varying amount (10-43 %). So, instead of sawing up the dumbbell handles, we add in some extra weights that we cannot fit on the dumbbell rack.
The name corn syrup is a giveaway: it betrays the fact that this product is manufactured from cornstarch (which was the scaffolding of lokum). If you remember that I described starch as a collection of glucose units, that should not come as a complete surprise! In fact, corn syrup contains poly-glucose units of varying length. But…watch out! Honey contains free glucose, too, roughly one third in weight. This means that, regardless of the exact concentration of free glucose in corn syrup, we can approximate the glucose : sucrose weight ratio to 1:3.
Then, I skimmed through the advice given at the start of the recipe:
“Be careful to have all mise en place ready as per the instructions. Once you begin the process, it should not be interrupted until the nougat is cooling“
“Sugar cooking temperature is critical. Use an accurate thermometer and cook the sugars carefully”
Ok, here we go. I deployed all pots and pans that I thought I would need and I set about working. I shelled the pistachio nuts and I added them to the almonds, storing them in a bowl in the oven, set at a low temperature (120 °C). After that, I separated the egg whites, leaving them in another bowl with a pinch of cream of tartar.
Then it was time to start cooking the sugar syrup, without honey, which I heated in a second saucepan, as suggested by the recipe. At first, the temperature was creeping up slowly, degree by degree, on a gentle heat. Then, the rate of increase in temperature quickly sped up, the number on the display fast approaching the target temperature of 150°C. Time to make the egg foam, and do it fast. While keeping an eye on the thermometer, I whipped the egg whites until the foam looked stiff enough. 148…149°C…time was trickling away as the temperature rose higher and higher. When it reached 150°C, everything happened in the blink of an eye: I grabbed the saucepan with the hot honey and I poured it into the syrup: the temperature dropped slightly, but it bounced back incredibly fast. I placed the metal bowl with the egg white foam in the kitchen sink, I snatched the large saucepan brimming with syrup, my left hand firmly holding the electrical whisk in mid air. I turned the saucepan, a moment that seemed to last forever, as it looked as if gravity would fail me. Suddenly, a thin trickle dived into the fluffy white. Down, pour it down, stream it into the foam, whisk it in, wield that whip, draw figures of eight as a sweet sticky mess is splattered all around. I kept on whisking for a few minutes; after that, I added the hot mixture to the nuts that I had set aside. I carelessly tossed the metal bowl into the kitchen sink, where it landed with a clanging noise as I was reaching for the roasting tray that I had lined with rice paper. The nougat-to-be was starting to cool down, and so I had to rush. I shovelled the thick white fluid into the tray with a silicone spatula, the pistachios and the almonds barely emerging from the surface as rocks submerged in an ivory sea. I laid the top sheet of rice paper with utmost and loving care, as though I were wrapping the lying nougat in a shroud.
Some sugar-honey syrup had spilt onto my kitchen sink, and set into a glassy amber slab (you can spot it in the featured image above!). I sort of thought I would find a mosquito trapped in one of them.
Later on, after a few hours’ rest, I pried the nougat out and I cut it roughly into bite-sized chunks. It was not the hardest nougat ever, but it seemed almost spot-on, also considering the limitations of my equipment, and the fact that I could not possibly cook the egg-syrup mixture for as long as 12 hours 9.
Little did I know that the hardest part was yet to come. In fact, storing homemade nougat can be tricky because of the hygroscopic nature of this sweet. Sugars will absorb moisture, and the nougat easily starts to ‘weep’, becoming stickier and stickier in the process. Aware of this issue, I thought I would outsmart the nougat this time: I stored the pieces in an airtight (borosilicate) glass container, which I put in the freezer overnight, just to be on the safe side. On the following day, I shared the nougat with friends and it was a great success, despite its texture.
Then, at a certain point, I flipped the container over, and I spotted a chip, then a fault line, and eventually a spiderweb pattern of cracks. All the bottom part of the nougat was keeping the bottom of the container together, becoming effectively inedible in the process. I salvaged the top layer, but the rest was lost. What a pity.
Trying to get candies right often looks like the toil of Sisyphus, the mythological giant condemned to keep pushing a boulder uphill only to see it roll back down once more.
Yet, “One must imagine Sisyphus happy”, suggests the French philosopher Albert Camus10.
Absurd as it sounds, that is so true. Never can we be freer and happier than when we take up those apparently pointless challenges bound to end, or fail, like cooking, loving, writing a poem or tasting a candy, those most treasured pleasures of our one and only life.
The most bittersweet delight.
Literally meaning ‘vast programme’, the closest English translation of this famous quote by De Gaulle is ‘a tall order’.
“[…]sugar is expensive, a spice that, in the Middle Ages, is produced only in Sicily and Andalusia, where sugarcane is grown. […] In France, sugar is mentioned for its medical applications as of the early 1200s, but it is seldom used as a cooking ingredient until the 1300s […]”. O. Redon, F. Sabban, S. Serventi, La gastronomie au Moyen-Age. 150 recettes de France et d’Italie, Editions Stock, 1993, Paris
Chemistry: The Impure Science, Bernadette Bensaude-Vincent and Jonathan Simon, Imperial College Press, 2012 (2nd edition).
On Food & Cooking, Harold McGee, Hodder & Stoughton, 2004
A. Baku and B. Kirmaci, Production of Turkish delights (lokum), Food Research International, 2009, 42, 1-
P.P. Greweling, Chocolates and confections :at home with the Culinary Institute of America,2010, Wiley
See this Wikipedia page (in Italian). This long cooking is required to obtain the rock-hard texture of certain types of torrone which, when snapped, will break and splinter into tiny shards. I remember, as a child, playing with these sticky pieces that would invariably cling onto the tablecloth.
“Il faut imaginer Sisyphe heureux”, Albert Camus, Le mythe de Sisyphe.
My chapped hands are wavering on the keyboard. They have weathered the storm.
The past is the bellowing voice of the wind and its gusts. It is blowing from a year ago, echoing a cascade of shed pearls spilling on the floor like tears, the piercing cry of a young tree felled by the howling gales, the creak of the brittle glass beaker that cracked, but that won’t break.
Listen, tonight, listen to the wind speaking.
It reminds me what I once wrote: I was sitting on an inflatable exercise ball, surrounded by scattered boxes, after a hurried relocation.
A year on, boxes and a ball once more, and an envelope I am holding in my hand. The most precious gift.
The hourglass turns, the sand grinds the glass down. Time is a rough substance, it trickles through our fingers, it scratches our skin, it won’t stop. This blog, too, shall go on. Drop by drop, what most counts is that what drips, but is not lost…
To mark this first year, here’s a collection of recordings (click and download, it won’t play otherwise). The voices of the laboratory where I work, sounds without men, voices of instruments, of appliances, of noises that speak.
Qui delle divertite passioni per miracolo tace la guerra, qui tocca anche a noi poveri la nostra parte di ricchezza ed è l’odore dei limoni
Eugenio Montale, I limoni
[…]Here, by some miracle, the war
of troubled passions calls a truce;
here we poor, too, receive our share of riches,
which is the fragrance of the lemons[…]
Eugenio Montale, The lemons (English translation of this poem found online).
Genova and The lemons
Take a map of the regions of Italy (or simply open an online mapping service…), and look northwest: a boomerang arches and embraces the stretch of sea in front of Corsica. This is Liguriaand Genoa (Genova, in Italian), its historical and current capital, lies at the centre of this arc, like a keystone in a vault. Affluent port city in the Middle Ages and financial hub, Genoa coexisted with (but at times also fought against) Venice, the other ‘seafaring Republic’, vying for commercial predominance and for the control of trading routes in the Mediterranean. Yet, Genoa has arguably beaten its arch-rival by a naval mile in the contest of literature and music. For example, many think that the finest cantautore (singer-songwriter) of all Italian 20th-century musica d’autore (untranslatable, but literally ‘author’s music’: think of the Italian counterpart to French chanson) is a native of Genoa, Fabrizio de André. He has even been hailed as ‘the greatest Italian poet of the last hundred years’: although this is definitely far-fetched, he did bring about a sea change in the landscape of Italian music, by writing songs about themes previously neglected, or tacitly banned, in the love-centred and somewhat soppy lyrics of contemporary singer-songwriters.
Now leave Genoa behind you and choose where to turn, right or left: take a look at the western and eastern ends of Liguria, and you will see two of the most celebrated, most influential Italian writers of the 20th century. Prose and poetry face each other: Sanremo, in the western tip, almost bordering France, is the Riviera resort where the novelist, essayist and short story writer Italo Calvino (1923-1985) spent his childhood and youth years; opposite across the sea lie the Cinque Terre(lit. ‘Five Lands’), an area of outstanding natural beauty and World Heritage Site, which greatly inspired the earlier lyrics by Eugenio Montale, born in Genoa in 1896, arguably the greatest Italian poet of the last century. Liguria is the land where mountains choose to escape their earthly nature and dive into the sea, the great salty blue beyond the shore that features in so many of Montale’s first poems; Liguria is the land where the rugged coastline can become complex and intricate, almost like a fractal, like the combinatorial or structuralist schemes informing some of Italo Calvino’s works. Invisible cities is the title of one of them: short descriptions of these “invisible cities” are arranged according to a thematic structure that follows an iterative order throughout the book. The overarching frame story of Invisible cities is Marco Polo’s fictional conversation with Kublai Khan about these cities, something clearly inspired to the 13th-century travel accounts of the real Marco Polo, The Travels of Marco Polo. A theme of Invisible cities includes “cities & memory”, and if I were to write my own account of the cities of my life, I would definitely place Genoa in this group…My invisible Genoa looks like Zora, one of Calvino’s invisible cities:
“Cities & Memory 4
Beyond six rivers and three mountain ranges rises Zora, a city that no one, having seen it, can forget. But not because, like other memorable cities, it leaves an unusual image in your recollections. Zora has the quality of remaining in your memory point by point, in its succession of streets, of houses along the streets, of doors and windows in the houses, though nothing in them possesses a special beauty of rarity. Zora’s secret lies in the way your gaze runs over patterns following one another as in a musical score where not a note can be altered or displaced. The man who knows by heart of Zora is made, if he is unable to sleep at night, can imagine he is walking along the streets […] This city which cannot be expunged from the mind is like an armature, a honeycomb in whose cells each of us can place the things he wants to remember.[…] Between each idea and each point of the itinerary an affinity or a contrast can be established[…]” (Italo Calvino, Invisible Cities, translated by William Weaver, Vintage Editions).
There are cities where we sense a resonance with their vibrations: we have never lived there, we do not even love them at first sight, and yet we strangely feel at home. There is usually no point in wondering why: it is just like a subliminal perception. So is Genoa for me, city and memory, and when I tread the stones of its twisted lanes I know that I am a stranger, a casual visitor to a city that maybe I do not even like; nevertheless, I feel at ease, moving effortlessly on those, in Montale’s words, frail “spiderwebs of the memory”, as if a vague reminiscence could still help me find my way. I navigate the visible city following the map of the invisible Genoa within me. On rainy days, gray skies loom large above the Ligurian Sea and you know that they are there to stay: the infamous ‘Genoa low‘ clashes against the mountains, squeezing rain onto the city from its spongy clouds. This is when I would think about Montale’s poem I limoni as I am wandering aimlessly, victim of a literary Wanderlust:
La pioggia stanca la terra, di poi; s’affolta
il tedio dell’inverno sulle case,
la luce si fa avara – amara l’anima.
The rain exhausts the earth then;
winter’s tedium weighs the houses down,
the light turns miserly-the soul bitter.
Then, as I picture myself following in Montale’s footsteps, like a Parisian flâneur in search of a flashing idea, I, too, yearn for that sudden surprise, the golden light of ripe lemons appearing all of a sudden after you turn into a narrow alleyway, the plump fruits hanging heavily from a lemon tree grown in a pot, standing in a courtyard.
Quando un giorno da un malchiuso portone tra gli alberi di una corte ci si mostrano i gialli dei limoni; e il gelo del cuore si sfa, e in petto ci scrosciano le loro canzoni le trombe d’oro della solarità.
Till one day through a half-shut gate
in a courtyard, there among the trees,
we can see the yellow of the lemons;
and the chill in the heart
melts, and deep in us
the golden horns of sunlight
pelt their songs.
A gate left ajar lets us catch a glimpse of the lemons, we would like to go and touch and smell the zesty fragrance of the rind. Yet, the concierge of the mansion spots us and rushes to locks us out. There we stand alone, in the torrential winter rain.
Chemistry and the invisible lemon.
Oxford is a very visible city, but lemons are rarely to be found. This is in stark contrast with Liguria, a land where citrus fruits have always flourished in the mild climate of the region, thanks to the protective embrace of the mountains. Some online sources report the whopping figure of 20-25 million lemons produced in the sole city of Sanremo in 1662. At the same time, somewhere north of the Alps, lemon trees started to be grown, too, requiring orangeries, glasshouses and conservatories: the renowned Botanic Garden of the University of Oxford still houses a couple of citrus plants in its conservatory, where they have been lovingly kept warm ‘since the 1600s’, as its website proudly states.
Anyway, it it time for chemistry and the kitchen. Once upon a night I found myself at a friend’s place, ready to do one of my favourite things: improvisation (aka “messing up”) in the kitchen, something I seldom allow myself to do because of the imprinting of my laboratory training. A jar of ready-to-use chickpeas peeping from a shelf was too strong a temptation for us to resist: let’s make some hummus! By the way, one could try and unify the entire Mediterranean world1 (and beyond) under the name of the blessed chickpea. We set sail from the western Andalusian coasts, where espinacas con garbanzos (spinach and chickpeas) are a staple dish, we lay at anchor for a stopover at any port of the Ligurian Sea, where the whole Riviera from Nice to Pisa feasts on flatbread made from chickpea flour (known as farinata in Liguria and socca in the Nice area), and, following the ancient sailing routes, we finally reach the shore somewhere in the eastern Mediterranean, for example the port of Acre, where ships from Genoa would once dock, load cargo, and trade, and where hummus will now keep our hunger pangs at bay.
The soft chickpeas easily yielded to the blade of the blender. Then I added some sesame paste, or tahini, and went on mashing the delicious mixture, tasting it on the go. Looking scrumptious. At this point, I turned to my friend and asked her: “Could you pass me a lemon or some juice please?”. Panic. The air stood still, those silent seconds where people cross their gazes without saying a word, knowing all too well what comes next. “I’ve got no lemon juice, I’ve got no lemons”, said she. Then she pointed to a small, bright green lime: “Use that instead!”, she suggested. I could have, maybe I should have, taken the lime and squeezed it, but I could not help grasping this opportunity for some unexpected “messing up” in the kitchen. I felt like frolicking and so I turned down the offer of the alternative citrus fruit and started thinking: “OK, let’s say that the little lemon juice added to the hummus is just there to correct the flavour: I don’t expect the texture of the hummus to depend a lot on the change in pH…the texture’s more a matter of balance between thick tahini and chickpea water”. In a sense, now I think that I was following the path traced by Italo Calvino in his quote above: “Between each idea and each point of the itinerary an affinity or a contrast can be established“.
Acidity: that is what lemon juice is (almost) all about. The holy book of all food lovers2 shows that the juice is 5 % in acids (as weight/weight percentage). The main sour character is citric acid, an interesting compound that ought to deserve much more than this brief mention in a blog post about hummus. For the moment, let us just remind that it is an allowed food additive, under the EU code E 330. Malic acid comes in a far second in the acid ranking, well below 0.5% 3 . Biochemistry lovers will remember that both citric and malic acid feature in the Krebs cycle, or citric acid cycle.
Then there is a sweet note to the flavour of lemon juice, which arises from the juice sugars, having a total weight content of 3.16 %, slightly lower than that of the acids.
However, as we all know, lemon is much more than its juice: the rind of the golden fruits has a pleasant, smell, arising from some fragrant molecules: limonene and citral in the first place. If we take a look at the molecular structure, we understand the significant difference between the reactivity of these two compounds.
Limonene is a sturdy molecule that belongs to the family of terpenes. You can mistreat it to a certain extent, and it will still be fine. It is a hydrocarbon, there is not much one can do to it unless one targets the double bonds. What I have drawn here is the stereoisomer found in lemon (question for those chemists who loved organic nomenclature as undergrads: is it R or S ?).
Citral, instead, seems poised to shortcut and curl into a comfortable 6-membered ring, with a little help from some acid, and all it takes for citral to become an aromatic molecule is some oxidiser. And beware: citral is actually a mixture of two isomers, neral and geranial, having a different smell.
Too bad citral falls apart in harsh conditions: a lemon-scented bleach or household detergent is the hallmark of cleanliness; if only citral were not so delicate! The quest for a substitute that could be stable in acidic and/or oxidising conditions has almost acquired a legendary status in the perfumery literature. It is cited for example in The Secret of Scent by Luca Turin, a must-read for perfume lovers, and maybe the focus of a future blog post.
Back to the kitchen, how could we introduce some acidity and some lemon-like flavours in the hummus-to-be? Spicing it up with the right ingredients, that was the way to go, but what to add? Fortunately, the kitchen larder was open and lots of spices were beckoning me over: I would quickly find what I needed.
First I sprinkled the hummus with a dark-red powder having a distinctive, tart note: there was sumac, hailing from the same part of the world as hummus itself, and the combination of the two is a match made in heaven. Sumac is a very peculiar spice in that it imparts acidity thanks to its high content in…yes, here we go, malic acid. Moreover, sumac came in with an additional bonus: it also contains some limonene.
Then I opened a small bag full of a brownish powder, and I savoured the fresh smell of ground coriander, its citral notes chiming with the taste I was trying to compose. I sprinkled the hummus with some coriander, I mixed, then I added a bit of olive oil and served. In the end, the lemon-free hummus was given the thumbs up by my friend.
But can one really assemble a lemon from, er… ‘first principles’, bottom-up? Do chemistry and cooking, which are both essentially combinatorial in nature, really have something in common?4
The curse of the alchemist
Regardless of the answer to those questions, what matters here is the idea of artefact contrasted to natural. Oh, here’s another Pandora box popping open…I promise that I will keep it short and simple (look elsewhere5 for the small print), while trying to be careful as I cross this minefield.
In a nutshell, (al)chemists have often been accused of concoct counterfeits, bogus surrogates of the real stuff, their ‘crime’ straddling plain quackery and outright fraud. From the arguments of Scholastic philosophers to today’s alleged supremacy of the natural (whatever it means) over the artificial or the chemical, the perceived image of (al)chemists seems to follows, at least ostensibly, a unique thread throughout the centuries. Dante Alighieri, in his Divine Comedy, places alchemists deep down in hell, in the Eighth Circle along with fraudsters, and more specifically in the same bolgia (a hole in the ground) as falsifiers. For the 10th-century philosopher Avicenna, alchemy is a form of deception, while the great Thomas Aquinas dismissed alchemy simply as an anomaly outside nature (‘praeternatural’). Today, the label ‘natural’ is often misused as a tacit antonym of ‘chemical’, leading to all sorts of paradoxes, chemistry as a scientific discipline being caught in the crossfire.
Yet, is the rift between the natural and the artificial still so deep? After all, the fear of some chemicals could easily coexist with an appreciation of others5, perceived as a boon to the society’s well-being. Indeed, the 2015 survey Public attitudes to chemistry in the UK by the Royal Society of Chemistry shows that people are quite pragmatic about chemicals, to say the least. Figures show that 60% of the public agree that “everything is made of chemicals” and 70% are in agreement with the statement “everything including water and oxygen can be toxic at a certain dose”. Paracelsus is alive and well, and we chemists should really take the time to sit down and reflect on our own preconceptions about the chemophobic public.
Calvino prematurely died 30 years ago. His legacy to Italian literature and culture is still under debate: some critics find that Calvino’s style and poetics have provided the following generations of writers with an invaluable framework; others, however, believe that his influence has ended up looming large on Italian literature, more as a magnificent hurdle to overcome than as a reference point.
At that time of his death, the writer was working on a series of lectures on literature to be delivered at Harvard. Fortunately, his notes were edited and collected in a book available in English translation, Six memos for the next millennium. Six seminars, each on a ‘value’ (and its opposite) that Calvino considered worthy of attention with an eye to 21st-century literature. Six memos for the next millennium and Invisible cities are similar in that they single out beacons, vital reference points helping us to navigate, respectively, the vast universe of literature or the everyday chaos that surrounds us. But like any map, we are free to choose if to trust and follow them or not.
At this stage, however, I would like to remember another book, The Castle of Crossed Destinies, in which Calvino crafts short stories by interpreting tarot cards randomly placed on the table. In this novel, mute characters who meet by chance in a castle or at an inn try to tell their own stories by picking, laying and arranging tarot cards; an onlooker, standing in for the writer, watches and tries to work out what the other characters try to narrate. From this point of view, The Castle of Crossed Destinies also draws on those great works of 14th century literature, Decameron by Boccaccio and The Canterbury Tales by Chaucher, which feature a group of characters taking turns at telling stories -and turns are part and parcel of all card games.
Anyway, in one of these tales, Calvino sees the trump card of The Magician (aka The Juggler, or Le Bateleur in the French original) as a proxy for the (somewhat stereotypical) alchemist, who tells how he sold his soul to the devil. Sounds familiar?
[…]our companion was, in fact, one of those scholars who scrutinize alembics and crucibles[…]trying to wrest from Nature her secrets, and especially that of the transformation of metals[…] from his earliest youth […]he had no other passion […] save the manipulation of the elements, and for years he had waited to see the yellow king of the mineral world precipitated in the depths of his cauldron.[…] This event must have been indicated in the following card, which was the enigmatic First Arcanum, sometimes known as The Juggler, in which some see a charlatan or magician performing his tricks […].
The second tale talking about alchemists is a much more intriguing piece, in my view: the alchemist is compared and contrasted to the figure of the knight-errant, and both of them come in with an alter ego, Doctor Faust (who else?) for the alchemist, and Perceval for the knight-errant. Put it in chemical terms, I see two resonance structures of the same molecule: the alchemist who “must (instead) free himself of all egoism […] to achieve transformations of matter“, who “tries to make his soul become as unchangeable and pure as gold” and Doctor Faust, “who inverts the alchemist’s rules, makes the soul an object of exchange” (Two tales of seeking and losing, pp. 90-91).
So, what kind of (al)chemist do you think you are?
Only now that I look back do I realise that this post has gone a long way, from Liguria through hummus to Calvino and eventually the Faustian ambitions of his alchemist. It is as if I were trying, as Marco Polo did in his travel accounts to Kublai Khan in Invisible Cities, to give an overview of the entire known world by piecing together his memories. Had he met the Faust of The Castle of Crossed Destinies, he would have agreed with him:
“There is not an all, given all at once: there is a finite number of elements whose combinations are multiplied to billions of billions, and only a few of these find a form and a meaning and make their presence felt amid a meaningless, shapeless dust cloud; like the seventy-eight cards of the tarot deck in whose juxtapositions sequences of stories appear and are then immediately undone” (Two tales of seeking and losing, p. 97).
Faust, this time I have got an ace up my sleeve, too.
Such stuff, that all is made on.
1. Neighbours are often too similar to love each other. So, there was a time when Pisa and Genoa, too, were at war. Memories of ferocious naval battles and bloodshed are still alive in the two cities. The same goes with the ongoing Israeli-Palestinian conflict. A humble suggestion: the chickpea could be the seed of durable peace… When I first wrote this footnote I was kind of joking, now I have found out that someone in Isreal has already done so: “Hummus joint gives Jewish-Arab tables 50% off“. As the newspaper writes with a witty humor, that’s chickpeace.
2. On Food & Cooking, Harold McGee, Hodder & Stoughton, 2004
3. Liu, Y., et al., History, Global Distribution, and Nutritional Importance of Citrus Fruits, in Comprehensive Reviews in Food Science and Food Safety, 2012, 11, 530–545. doi: 10.1111/j.1541-4337.2012.00201.x
4. According to a Lebanese cook who took part in a food programme on the French radio, On va déguster, replacing lemon with sumac in hummus is tantamount to blasphemy. If you speak French, you can listen to the programme, focussed on Middle Eastern cuisine from Aleppo to Tel Aviv through Lebanon.
5.Chemistry: The Impure Science, Bernadette Bensaude-Vincent and Jonathan Simon, Imperial College Press, 2012 (2nd edition).
6. All quotes from The Castle of Crossed Destinies, translated from the Italian by William Weaver, Secker & Warburg (London), 1976