The Silent Poetry of Paint Drying

The painting has a life of its own. I just let it come through.

Jackson Pollock (1912 – 1956)

Over the last six weeks or so, I’ve had the immense pleasure of collaborating with local artist Lynda Jackson on a project for Creative Reactions — the arts-science offshoot of Pint of Science   I don’t quite know why I didn’t sign up for Creative Reactions long before now but after reading Mark Fromhold‘s wonderful blog post about last year’s event, I jumped at the chance to get involved with CR2019. The collaboration with Lynda culminated in us being interviewed together for yesterday’s Creative Reactions closing night, which was a heck of a lot of fun. The event, compered by PhD student researcher Paul Brett (Microbiology, University of Nottingham), was expertly live-tweeted by another UoN researcher (this time from the School of Chemistry), Lizzie Killalea

I’ve been fascinated by the physics (and metaphysics) of foam for a very long time, and was delighted that the collaboration with Lynda serendipitously ended up being focused on foam-like painting and patterns. When we met for the first time, Lynda told me that she had a burgeoning interest in what’s known as acrylic pouring, as described in this video…

…and here’s a great example of one of Lynda’s paintings, produced using a somewhat similar technique to that described in the video:

LyndaJackson_2.png

I love that painting, not only for its aesthetic value, but for its direct, and scientifically beautiful, connection to the foam patterns — or, to give them their slightly more technical name, cellular networks — that are prevalent right across nature, from the sub-microscopic to the (quite literally) astronomically large (via, as I discuss in the Sixty Symbols video below, the Giant’s Causeway and some stonkingly stoned spiders)…

Our research group spent a great deal of time (nearly a decade — see this paper for a review of some of that work) analysing the cellular networks that form when a droplet of a suspension of nanoparticles in a solvent is placed on a surface and subsequently left to its own devices (or alternatively spin-dried). Here’s a particularly striking example of the foams-within-foams-within-foams motif that is formed via the drying of a nanoparticle-laden droplet of toluene on silicon…

Nanoparticles-2.png

What you see in that atomic force microscope image above — which is approximately 0.02 of a millimetre, i.e. 20 micrometres, across — are not the individual 2 nanometre nanoparticles themselves, but the much larger (micron-scale) pattern that is formed during the drying of the droplet; the evaporation and dewetting of the solvent corrals the particles together into the patterns you see. It’s somewhat like what happens in the formation of a coffee stain: the particles are carried on the tide of the solvent (water for the coffee example; toluene in the case of the nanoparticles).

Lynda’s painting above is about 50 cm wide. That means that the scale of the foam created by acrylic pouring is ~ 25,000 times bigger than that of the nanoparticle pattern. Physicists get very excited when they see the same class of pattern cropping up in very different systems and/or on very different length scales — it often means that there’s an overarching mathematical framework; a very similar form of differential equation, for example, may well be underpinning the observations. And, indeed, there are similar physical processes at play in both the acrylic pouring and the nanoparticle systems: mixed phases separate under the influence of solvent flow. Here’s another striking example from Lynda’s work:

LyndaJackson_1.png

Phase separation and phase transitions are not only an exceptionally rich source of fascinating physics (and, indeed, chemistry and biology) but they almost invariably give rise to sets of intriguing and intricate patterns that have captivated both scientists and artists for centuries. In the not-too-distant future I’ll blog about Alan Turing’s remarkable insights into the pattern-forming processes that produce the spots, spirals, and stripes of animal hides (like those shown in the tweet below); his reaction-diffusion model is an exceptionally elegant example of truly original scientific thinking. I always hesitate to use the word “genius” — because science is so very much more complicated and collaborative than the tired cliche of the lone scientist “kicking against the odds” — but in Turing’s case the accolade is more than well-deserved.

I nicked the title of this post — well, almost nicked — from a quote generally attributed to Plutarch: “Painting is silent poetry, and poetry is painting that speaks.” It’s very encouraging indeed that Creative Reactions followed hot on the heels of the Science Rhymes event organised by my UoN colleague Gerardo Adesso a couple of weeks ago (see Brigitte Nerlich‘s great review for the Making Science Public blog). Could we at last be breaking down the barriers between those two cultures that CP Snow famously identified so many years ago?

At the very least, I get the feeling that there’s a great deal more going on than just a superficial painting over the cracks…

Vying with the viva

This week’s Times Higher Education‘s cover feature is “Lighting The Way“, on the theme of PhD supervision. Along with five other academics, across a range of disciplines, I was invited by Paul Jump to contribute my thoughts on the role of the PhD supervisor. The editorial (by John Gill) sums up my central point as “the fundamental responsibility [of the PhD supervisor] is still to nurture independence such that the doctoral candidate ceases to be a student and becomes a peer.” That’s a fair summary. I also reiterated my commitment to referring to PhD researchers, rather than PhD students, in line with Jeff Ollerton’s important suggestion.

I’ve had the “Vying with the Viva” title of this post stuck in my head for a little while now and the publication of the Times Higher article seems as timely a moment as any to jot down some tips for PhD students  researchers who are preparing for a viva voce examination. I should first say that just about everything you need to know about doing a PhD is covered in a wonderful book by an alumnus of the Nottingham Nanoscience Group, James Hayton, whose PhD it was my absolute pleasure to supervise. I cannot recommend that book highly enough (and not only because it demonstrates that Dr. Hayton managed to survive my supervision and come out the other side relatively unscathed, if perhaps swearing a little more often than is strictly necessary.) James also has a great blog, website, and series of videos on the many peaks and pitfalls of doing a PhD.

I thought, however, that it might be helpful for those about to undertake a viva to hear from someone who has examined PhD candidates (as both external and internal examiner) at the rate of about three or four per year (on average) over the last couple of decades. At this point in my career, I have also been primary supervisor for a total of twenty-six students. (Twenty-two have completed their thesis to date. The remaining four are in 1st year (Oli), 2nd year (Joe), and the final year (Alex and Filipe) of their PhD project, respectively.)*

I should stress that what I write below is UK- and Ireland-centric and is from the perspective of a condensed matter physicist/nanoscientist (although I could also just about get away with calling myself a chemical physicist/physical chemist, given the research we do.) The examples chosen obviously reflect my research background and examining experience but the advice is, I would say, broadly applicable for all disciplines.

My own viva, back on a snowy January morning in 1994 — with the wonderfully-monickered Iggy McGovern, physicist and poet, as my external examiner** — was very similar in style to those I’ve since attended as examiner rather than candidate. The PhD researcher sits on one side of a table, with the examiners — one from a different university (the external), the other from the same university as the candidate — seated opposite. Sometimes (though very, very rarely in my experience), the PhD supervisor will also attend, and in Ireland it’s more common to have a moderator in place to ensure that the candidate and examiners don’t come to blows. (Joke. Usually.)

OK, on with those tips for a successful viva (in no particular order)…

1. Have a practice viva.

2. Have a practice viva.

3. Have a practice viva. Excuse my hammering home the message quite as bluntly as this but if I were forced at gunpoint to give only one piece of advice it would be the following: ask your PhD supervisor to do a mock viva with you and do not take “no” for an answer. If there’s another academic member of staff or postdoc willing to be involved, all the better — they can take the role of the internal examiner and your PhD supervisor can pretend to be the external. They should aim to grill you mercilessly. And if it takes two or three attempts at the mock viva to fully prepare you for the real thing, so be it. (The mock need only take an hour or less. That’s enough, generally, to identify where there might be issues.)

We do this in our group at Nottingham for every PhD researcher (a couple of weeks before their actual viva) and we do not hold back. They leave the mock viva feeling somewhat shell-shocked but that’s entirely the point: it’s much better to come to terms with key gaps in knowledge or understanding before the actual viva. And in the end, most of our alumni find that the real viva was a piece of cake compared to the mock.

4. Every word in your thesis is examinable.  Do not simply rearrange the words in a textbook or a review article when it comes to writing the background material. Know what those words mean. For example, if you’re an experimentalist, don’t write about particular functionals used in density functional theory (DFT) if you have absolutely no idea what a functional is (and how it differs from a function). Or, if you’re a theorist, don’t wax lyrical about phase errors in a phase-locked loop if you haven’t a clue as to how a PLL does what it does. (These are both examples I’ve encountered when I’ve been external examiner.)  And it goes without saying that you don’t cut and paste from that article or textbook. That’s plagiarism. Even if it’s just one sentence. And, no, “I couldn’t word it better than it was written” isn’t an excuse. But you know that.

5. Don’t ramble. If you don’t know the answer, just say so. Obviously, try not to reply to each question you’re asked with “I haven’t a clue” but you are not expected to know the answer to everything. Indeed, the examiner is often asking because they don’t know.  If you start rambling you can very easily start digging yourself a hole out of which it’s sometimes difficult to crawl. I certainly did this in my own viva because I chatter when I’m nervous.

6. Don’t neglect the fundamentals. This is where most PhD candidates come unstuck. There seems to be a perception that the viva will focus on the minutiae of the most arcane technical detail in your research over which you have probably lost many nights of sleep. The overwhelming odds are that your examiner won’t even have noticed this aspect of your work. They’ll focus on the much bigger picture. (See also #7.)

If your PhD is on simulating intermolecular interactions, for example, be damn sure that you are completely au fait with those pair potentials due to Morse and Lennard-Jones that you covered all the way back in Year 1 or Year 2 of your undergraduate degree. Similarly, if you’ve been determining forces from a potential energy landscape measured by an atomic force microscope, ensure that you have slightly more than a passing familiarity with scalar and vector fields. Dig out those undergrad vector calculus notes and make sure you understand how force and potential are related, for one.

You can’t, of course, prepare for every question. But it’s worth thinking carefully about which key principles of physics/chemistry underpin your research. (We’ll take the 1st and 2nd laws of thermodynamics as given. You can, of course, state the 1st and 2nd laws with confidence, right?) In the case of my viva, Prof. McGovern took me from vibration isolation for a scanning tunnelling microscope (STM), to the eddy current damping exploited in most STMs, to Faraday’s law of induction. (Thanks for that, Iggy.)

7. Think big. I tend to start the vivas I do with a simple question along the lines of “Why did you do a PhD?” or “Which aspect of your work is the most important/you’re most proud of?” or “Explain your work in a few sentences and in language that a GCSE student could understand.” My aim is to try to put the candidate at their ease. This backfires sometimes, however, because the candidate clearly is not expecting a general question of this type. Sometimes they are completely flummoxed.

A key part of the viva process is to ascertain the extent to which you understand the broader context of your work. Why is it important? Why should anyone care? What value does it have in terms of pushing your field of study forward? You need to sweat the small stuff, to borrow a phrase from our friends across the pond, but you also need to be able to see the wood for the trees.

8. “My supervisor told me to do it” is never, ever, ever the right answer. You’re being examined to assess your ability to be an independent researcher. If you don’t know why you did a particular experiment or calculation the way you did, find out right now. And ask yourself whether that really was the best way to do things. (I should note that I’ve been given “My supervisor told me to do it” as a reply on significantly more than one occasion.)

9. Forewarned is forearmed. Look up your examiners’ group web pages and publications. Take some time to familiarise yourself with the research they’ve done. Unless something has gone badly astray in the examiner selection process, their research area is not going to be light years from yours. Do your homework and you might even be able to preempt a question or two.

10. We are almost always on your side. Yes, there are one or two complete bastards out there who are deeply insecure and unpleasant individuals; they’ll take pleasure in attempting to humiliate a candidate during a viva. I’ve not encountered one of these (thus far) but I’ve certainly heard from postdocs who have had to suffer arrogant, patronising, and, in the worst cases, bullying PhD examiners.

To put this in context, however I have now done somewhere between sixty and seventy vivas (as external or internal examiner) over the course of my career to date and I’ve not encountered this type of behaviour. I would also very much hope, of course, that I have not made any of the PhD candidates I have examined feel as if they were being patronised (or worse.) We examiners want you to pass!

11. Try to enjoy yourself. Despite receiving quite a grilling from Prof. McGovern, I enjoyed my viva. It’s nerve-wracking, of course, but when you’re talking about the research you love with someone who is genuinely interested in the work, it can also be exhilarating.

No, really. It can.

I’ll leave you with a wonderfully affecting Sixty Symbols video that follows my friend and erstwhile colleague at Nottingham, James Clewett, through his viva experience…

To quote James,

“In the end…it was a very comfortable… very enjoyable experience. It was something that, in hindsight, I’d do it again.”

Oh, and that reminds me…

12Don’t wear shorts.

* Thank you Mike, Mick, Li, Rich, Fiona, Matt, Andy, Manu, James, Adam, Pete, Cong, Rosanna, Haya, Sam, Julian, Cristina, Ioannis, Morten, Jeremy, Simon, Alex, Filipe, Joe, and Oli.

** It was a lot of fun to work with Iggy seventeen years after my viva on this video:

 

Rhapsody in Q

While digging through my e-mail archive to find a completely unrelated e-mail from years ago, I unearthed the following wonderful parody progress report (for the month of January 2012) from Julian Stirling, a PhD student researcher in the Nottingham Nanoscience Group at the time.  I just couldn’t leave it languishing in the archive so have released it into the wild here. Julian’s PhD project was focussed on various aspects of the qPlus variant of atomic force microscopy (described by its originator Franz Giessibl in the video below).

At the time of writing his Jan 2012 monthly report, Julian had been working on an analysis of the tip geometry in qPlus AFM which was later published in the Beilstein Journal of Nanotechnology.

Over to you, Julian…


Is this a real force?
Is this just fantasy?
I am not sure if they
Line up with reality

Open a book,
Look up at the maths and see…

It’s not a good guess, look at condition three.
Tips are, rather big, rather long
Rather like, other prong,
Any way the tip moves, all this matters to me.

To me…

Da-dah!
I just solved the math,
Put a pen against board,
left no solution unexplored

Da-dah… This has just begun,
Because now I got to work out what it means

Da-dah woo-hooo,
Didn’t mean to stop and cheer
If I’m right there is work to do tomorrow
Carry on, carry on as if nothing’s really finished

Look now, simulation’s done:
Sends vibrations down the tine
Oscillating all the time
Hey look, ev’rybody, the way it moves,
Gotta see the graph and try to face the truth

Da-dah woo-hooo,
I don’t want to stop,
I sometimes wish I’d never solved this at all

I see a little simulation of a tine,
Look at that! Look at that! Do you see the lateral motion?!
Eigenmodes and vectors, simulate detectors! Gee!
Galileo, Galileo
Galileo, Galileo
Galileo, Figaro – magnifico

Its just a theory, no one believes me
Its just a theory, why should we believe thee?
Just take a look at a this spectroscopy!
In it comes, out it goes, will you watch it go?
Bismilah! No, we will not watch it go
(Watch it go!) Bismilah! We will not watch it go
(Watch it go!) Bismilah! We will not watch it go
(Watch it go) Will not watch it go
(Watch it go)(Never) Never watch it go
(Watch it go) Never watch it go (Watch it go) Ah
No, no, no, no, no, no, no
Oh mama mia, mama mia, mama mia, watch it go,
Beelzebub had a simulation put aside for me
For meeeeeeeeeeeeeeee!

So you think you can model me and predict how I scan?!?!
So you think you can simulate all that I am?!?!
Oh, Euler- can’t do this to me Euler,
Just gotta derive, just got to derive it in full

All this really matters, Anyone can see,
All this really matters,
All this really matters to me…

Any way the tip moves…

“I Can See Her Again”

I’m well aware that I’m skirting dangerously close to Mary Ann Bighead (of Private Eye fame) territory with this short post, but I am immensely proud of my daughter, Saoirse, for having her poem published  in a book of poetry last week. The book in question, “Poetry Emotions“, is a collection of poetry written by children from schools across the Midlands. Here’s Saoirse’s poem.

I click “play” on the movie in my head.
And I can see her again.

Her soft black hair glistening in the sunlight,
as she leaps and bounds over the fields.
Skipping, jumping.

It’s as if she’s an angel,
Staring down at me with immense concentration.

And it’s as if she just floated away leaving only a shadow in the sky.
A tear trickles down my cheek.
I feel like it was all my doing,
I can remember how it used to be.
Playing in the fields and meadows, singing and laughing.
I can remember her sweet voice.

She looks at me and I look at her.
Our gaze is locked in time.

I see her again and I remember, my best friend…

Saoirse Carroll-Moriarty (9)
Middleton Primary & Nursery School, Wollaton, Nottingham