Tuesday 7 May 2024

Please (don't) take a seat

 At the recent solo-exhibition of Sung Hwan Kim at the van Abbe Museum I encountered the following set up:

In case my low-quality phone photograph isn't clear enough, what we have here are two rectangular black objects made of wood. They are of near-identical height and placed on the floor about 1,5 meters in front of a screen that is showing a video.
What is strange about this is that one is marked 'Please take a seat', while on the other it's written to 'Please don't sit'.
To include two almost identical objects with opposite functions is such an absurdly stupid decision that it could have easily been the premise for a Monthy Phython sketch.

Friday 26 April 2024

The Difficulty of Forgetting

A few months after my grandmother died, there were a few of her belongings left at my parents' house, including a simple painting of a farm. 'We tried to see if it was worth something', my dad said. 'And it was about sixty euro's', I immediately replied. 'Yeah! Yeah, it was!', he said, surprised, as if he had no idea how I spent my time in the preceding fifteen years. He naturally was also a little bit disappointed with the painting's value. It had hung so long in my grandmother's house that the whole family probably thought it was very valuable.
In either case, I don't know where that painting is currently. Perhaps in my parents'  attic, or at an uncle's house. I can't even rule out the possibility it was simply thrown away.

My point is that whenever I see the claim that an artist was 'rediscovered', they were never forgotten or unrecognised in the first place. It takes a substantial amount of attention, effort, space and other resources to preserve any kind of artwork for more than a few months, let alone decades or centuries. So whenever I see more than a single work turn up by a 'forgotten' artist, you just know that that's a false claim. Somebody somewhere cared very deeply about those works and went to great lengths to safeguard them.

Tuesday 23 April 2024


The chemical benzene is apparently an attractive proposition for a number of artists.
Benzene has a unique spatial structure that makes it stand out from other molecules. It has been known since the 1800's that benzene consists of six carbon atoms and six hydrogen atoms. It was also known that carbon-based molecules are generally spatially arranged in connecting tetrahedrons. As this is impossible to achieve with an equal number of carbon and hydrogen atoms, it has been a long standing mystery on how these atoms were arranged in the molecule.
The beginning of the solution was offered in 1865 by August Kekulé, who proposed a geometrically flat hexagonal 'ring' structure with alternating 'double bonds', which he visualised in the following manner:

This is the actual model Kekulé built to demonstrate the structure. It is now in the collection of the University Museum in Ghent, Belgium, where Kekulé was living at the time.
In this model the black balls represent carbon atoms, the white balls are hydrogen atoms and the connecting metal rods are single and double bonds. Such bonds are connections between atoms created through both atoms 'sharing' a pair of electrons. In a double bond two pairs of electrons are thus shared between two adjacent atoms.
After the 19th century, quantum mechanics and molecular orbital theory have further refined this view. Yet the general principle of benzene consisting of six carbon atoms in a planar hexagonal shape still stands, with the six hydrogen atoms arranged like 'antennas' at opposite ends of, and in the same plane as, the hexagon. As such, it is usually graphically depicted in one of the following ways:

It's obvious that artist Monira Al Qadiri had these (simplified) graphical structures in mind when she started on her work 'Benzene' in 2022. This work consists of a series of sculptures where, according to her, 'the scientific geometry of benzene's chemical compounds are rendered into glass sculptures, in order to highlight the grip that this perfumed molecule has on our lives.' While most of these structures are straightforward translations of the above shown schematics into three-dimensional glass shapes, one of them caught my attention:

To any chemist it's immediately obvious that this is completely impossible and has nothing to do with any kind of reality. Al Qadiri's claim to 'the scientific geometry' is thus hardly scientific.
To understand why this is so you need a bit of technical understanding about delocalized π-electrons in the structure of benzene and where possible lone pairs of electrons would go if they hydrogen atoms were displaced. Since providing such understanding isn't really attainable within the scope of this blogpost, let me just say that Al Qadiri's sculpture is a bit like stating that this is what a functional bicycle looks like:

Al Qadiri further places emphasis on the smell of benzene. She says that benzene is 'a colourless and highly flammable liquid with a sweet smell, it is partially responsible for the aroma around petrol stations, and is thus classified as an ‘aromatic hydrocarbon.’ ' It is in this manner that she makes the connection between benzene and the petrochemical industry. While benzene is (non-exclusively) extracted from crude oil, the connection she makes with petrol stations is partially a false one. Benzene is a minor part of gasoline, of only approximately 1% by volume. It thus doesn't contribute greatly to any particular core property of gasoline, least of all it's flammability. This flammability is much more influenced by short-chain alkanes like butane and hexane, which have far lower boiling points and oxidize much more rapidly. In fact, a mixture of benzene and benzene-like molecules called BTEX is sometimes added to gasoline to reduce its combustibility.
The second part of her statement, where she links the smell of benzene to its classification as an 'aromatic hydrocarbon' misunderstands cause and effect. It is true that in 1855 August Wilhelm Hoffman gave the classification of 'aromatic acids' to a number of compounds, even if not all them had  a distinctive smell. We now know the core component of those 'aromatic acids' was the presence of a benzene-like structure and the 'aromatic' moniker has thus stuck for those kind of molecules. Their properties and uses vary wildly, however. Besides benzene, photographic developer is also aromatic and so are the basic building blocks of DNA. Al Qadiri's observation is thus far removed from an explanation of any of benzene's properties or 'the grip it has on our lives'.

Less poetically interpretative, but equally misinformed, is a much earlier example by the hand of Bernar Venet. At the time known for his appropriated 'scientific' drawings, Venet made the following 'drawing' in 1966:

The text, in French, describes the 'importance of Kekulé's formula'. According to Venet this 'formula allowed us to interpret the hydrogenation of benzene to cyclohexane and the chlorination to benzene hexachloride.'
I'm not exactly sure what he's attempting to express here. Hydrogenation of alkenes to alkanes using platinum catalysts was first published in 1874, some ten years after Kekulé's discovery, and I'm not entirely sure this process would work on the more stable structure of benzene. How it helps us 'interpret' this process is thus unclear to me, as it implies that the discovery of the process came after the explanation that process.
Furthermore, the process of 'chlorination' generally refers to simple addition of chlorine to a molecule. In this case you would thus end up with hexachlorocylcohexane, not hexachlorobenzene as is claimed in Venet's text. But it is possible to make hexachlorobenzene from benzene with a substitution reaction, so lets just assume Venet meant this instead. In that case he describes the structural formula of 'hexachlorobenzene' as C6H12Cl6. This formula is simply impossible. A carbon atom can only be connected to four other atoms at the same time. In a ring structure, two of those possibilities are already taken up by the neighbouring carbon atoms, which leaves us with a total of 12 'free' spaces. As we have 6 chlorine atoms and 12 hydrogen atoms in Venet's proposed formula, we apparently need to fit 18 atoms into the 12 available possibilities. The correct formula would thus be C6H6Cl6 for hexachlorocyclohexane or C6Cl6 for hexachlorobenzene.
Furthermore, in order to show the formation of benzene, Venet uses the so-called trimerisation of alkyne as his example. This is an unusual choice from a chemical point of view. Firstly because this process was first described in 1866, one year after Kekulé published his formula. And secondly because t
rimerisation is a very difficult reaction to perform. It has a very high activation energy, thus requiring high temperatures of >800 ºC, and even then the end result isn't pure benzene but a mixture of different products. Therefore this reaction was far from efficient, or common, until a different process was developed in the late 1940's that involves the use of catalysts, which made alkyne trimerisation a viable reaction in routine synthesis work.
Thus while I generally enjoy the drawings of Venet for their stylized simplicity, it's best to not actually read the text that's contained in them.

Richard Venlet is a third artist I've encountered who has an interest in benzene and it's structure. He published a booklet with the title Kekulé in 2011. Its starting point was the anecdote of August Kekulé's first insight into the structure, which took place while he was living in Ghent, Belgium. 

Venlet presents no claims to scientific knowledge and his little booklet seems to be nothing more than a happenstance that reflects his interest in hexagonal shapes, like the ones he used for a series of floor panels created for Maniera two years prior:

As is clear to see, in the booklet Venlet presents a repeating pattern of hexagons, as he would show in his exhibitions. The reference to Kekule and his structure of benzene is thus a pure formal one. Nevertheless, it must be pointed out that the structure he presents is chemically impossible. The flat structure of such a system, like in the well-known graphene, is only possible through the 'double bonds' present in benzene, or rather its delocalized π-system. Such a system is usually represented by the addition of extra lines in certain places, which are missing in Venlet's drawing. Although seemingly a small difference, this has great consequences for the spatial arrangement of such a molecule, which would put an impossibly large strain on the system that Venlet represents. The following illustration hopefully gives a sense of the factual differences that are left out of such simplified illustrations:

It should be easy to see that a so-called saturated system that Venlet has drawn is far more crowded and therefore possesses very little room to move and wiggle, something all atoms want to do. While it might be possible on a smaller scale like the above illustration, a large field like the one presented in Venlet's booklet will in reality simply fall apart and find a different conformation.

In conclusion I should once again state that although I have never expected otherwise and can occasionally enjoy the fantasy-rich interpretations of artists, it's nevertheless a good idea to presume that an artist's factual understanding of the natural sciences is negligible. When I asked as a chemist I know why he enjoyed working with artists, he simply said 'it's so nice to see people who are unburdened by knowledge'.

Monday 22 January 2024

Testing, Testing.

Recently I wrote about some watercolours I've made. Since then I've found some scientific literature on the subject, after discovering that the 'coffee ring effect' is the scientific name of a ring shaped deposit found after a drop of liquid has dried. It's a relatively new field of study, with major research only being done since the late 1990's. This literature does confirm my basic assumption of the movement of the paint particles, which is explained by capillary flow. The literature also shows that there are many competing phenomena and variables at play, which are difficult to measure and analyse. Many of the papers I found focus on variables like temperature, relative humidity and electromagnetic influences, most of which effect the rate of evaporation.

I've done some experiments to test the influence of some of these parameters on the appearance of my own drops of watercolour, with some notable results.

First I tried to measure the influence of temperature. The results of this were mostly inconclusive. To test the influence of temperature, I uniformly applied the droplets at three different temperatures, to see if their appearance would differ after drying. The expected result from some of the literature would be that a higher temperature creates a more even distribution throughout the drying droplet. Various mechanisms have been suggested on how this works, including a greater evaporation at the contact surface with the air, which causes greater flow inside the droplet, as well as a 'surface capture' effect of particles at the contact surface.
In the rudimentary testing I have done I however didn't notice any significant effects of temperature on how uniformly the paint spread through the drying droplet:

Three drops dried at different temperatures

In this image there are three droplets of about 2 mm in diameter, made with Winsor and Newton's Payne's grey watercolour paint. The first was made on a substrate that's cooled below 0ºC, the middle was made at room temperature and the last one was heated after application in an oven to about 70ºC. It's clear that there is little significant variation between these three droplets, thereby giving indication that temperature, at least on this scale and with these materials, is not a significant contributing factor for the distribution of the pigments in the drying droplet.
However, the influence of temperature might be dependent on the exact chemical composition of the pigments, in combination with corresponding changes in the binders used. The following image consists of the results of the same experiment, showing Daniel Smith's Hematite Genuine watercolour paint, in duplicate, at <0ºC, room temperature and ~70ºC, respectively.

Two sets of three drops dried at different temperatures

What one can observe here is greater ring formation with a cooled substrate and more concentration at the center at elevated temperatures. So much so that the ring where the pigment is deposited is not even found at the outer edge of the droplet, which is something I have not observed in other situations. This behaviour is also the exact opposite of what the literature would have us expect.

When examining the literature, it must also be noted that most of the literature on the coffee ring effect seeks to eliminate it, because in an analytical or manufacturing context its existence is commonly detrimental to achieving uniform depositions or measurements. Relatively little literature thus exists on controlling the formation of the ring itself, and as far as I can tell, all research is done on colloids that are mixed prior to droplet formation. Little to no research has been done on the effects of introducing a colloid to an existing droplet. Yet I've found indications that for our purposes this provides a lot of control on the exact formation of the coffee ring, as can be seen in the following image:

Four different ways of introducing the paint

From left to right, this is a simple droplet of a diluted suspension of Winsor and Newton Payne's grey watercolour, a water droplet to which a diluted suspension was added at the centre point of the droplet after droplet formation, a water droplet to which a diluted suspension was added at the right edge of the droplet after droplet formation and a water droplet to which a near-saturated suspension was added at the right edge of the droplet after droplet formation.
As you can see, the two leftmost droplets dried nearly identical, even if their method of application was very different. For the third droplet from the left, paint was added later at an angle on the right edge with the paper, and this saw most of the pigment end up around the full perimeter of the droplet. This process was repeated with a higher concentration of pigment in the last droplet and while this contained far more pigment than the other three droplets, still most of it stayed at the perimeter of the droplet, with even more seemingly remaining at the initial point of introduction.

My explanation for this is that a similar outward pushing effect is at work here, inhibiting the possibility for pigments to enter the centre of the droplet through gravity or other forces.
It must however be also noted that in some degree this is dependent on the exact shape of the droplet and again the composition of the paint.

Three different ways of introducing the paint

In this image we have a droplet with a homogenous solution of Daniel Smith's Venetian Red water colour paint, followed by a saturated solution of the same paint added at the right edge of a droplet of water and ultimately a heavily diluted solution added at the right edge of a droplet of water. They each have their distinctive appearances, which differ subtly from the previous experiment with Payne's grey, most notably with the later introduction of a saturated solution. This produced a light centre with a thick edge in the previous experiment, while it created a mostly even spread with a thin edge in the latter example.

Even though it's difficult to observe this behaviour in real time and at actual scale, I believe the observations from the previous two figures is related to the behaviour of the pigment at the droplet's contact surface with air. I did a test where I placed a small saturated spot of Payne's grey watercolour on a piece of paper, let it dry, and then added a water droplet, without physically disturbing the spot of paint. What I found after this droplet had dried is that the paint had spread uniformly throughout the droplet, with a clear coffee ring effect present. There thus is a tendency for the paint to be distributed inside the droplet if it gets far enough inside. 

Adding water to a dried spot of paint

Generally speaking, predicting the exact behaviour of the interaction of a fluid and a colloid is complex and very difficult, as can be seen in the following example:

Introducing two paints into a single droplet

In this image two different watercolour paints are added to a single droplet. The droplet at the top was a diluted solution of Daniel Smith's Quinacridone Gold water colour paint, to which a saturated solution of Daniel Smith's Quinacridone Red was added on the right side at an angle. The droplet at the bottom was pure water, to which Quinacridone Gold was first added at the top and then Quinacridone Red was added on the right side at an angle. As is clearly visible, the latter process resulted in a nearly homogenous mixture, while the first gave a degree of separation between in the colours in the dried droplet.
However, I then repeated this experiment using Daniel Smith's Quinacridone Gold and Winsor & Newton's Payne's grey.

Introducing two paints into a single droplet

Here the same procedure was followed, with the Payne's Gray being added first, followed by Quincridone Gold on the right side at an angle. The way the paints mixed was the opposite of what I observed in the previous experiment. On this occasion the Quinacridone Gold mixed better with the droplet of diluted water colour, while the two paints stayed separated when added in sequence to a droplet of pure water. At the present time I have no simple explanation for this seeming contradiction in behaviour.

Lastly I want to note another characteristic I hadn't considered up until this point, which is the influence of magnetic effects on the droplets. Naturally electromagnetic effects are strong if there are ferromagnetic pigments present in the paint. Especially in the case of paints that contain a mixture of magnetic and non-magnetic pigments, introducing a magnetic field during the drying process produces interesting effects that can be easily controlled with the presence of any magnetic field. 

In conclusion, about a month has past since the previous post and I have still made some new observations about the behaviour of the watercolour paint inside a droplet. Some of these observations seemingly contradict the explanations found in current scientific literature, while others provide a possibility for new methods that are hitherto unexplored.

Tuesday 16 January 2024

The Artist's Artist's Critic's Critic

During 2023 I recorded most of my visits to exhibitions on a website called The Artist's Artist's Critic's Critic. On this website I scored each exhibition one to five stars on six characteristics: difficulty, entertainment, originality, legibility, consistency and craftsmanship. I also recorded the time spent at the exhibition as an indication of my affinity with the work.
Part of the reason I started this undertaking was to see if I could develop an alternative to the subjective and nonsensical star rating system that's used by various media outlets. By trying to formulate those aspects of an exhibition I adhere importance to, I thought it might be possible to provide some insight into my own viewing behaviour, while still having a numerical ranking system.

Now the year is over I have crunched some of the numbers and it gave some interesting results.

In 2023 I recorded 79 exhibitions. 65 of those were solo shows, of which 31 were at museums, 21 at galleries and 13 at other institutions. Of the 14 group exhibitions I recorded, 7 were at museums and 7 took place at other institutions. I visited no group shows at commercial galleries.

When rating something 1 to 5 stars on six different characteristics, the range of the total scores lies between 6 and 30, with an average of 18. This equates to a 3-star score on all six characteristics.
The average total score I've given to those 79 exhibitions is 18,25, with a median of 18 and modes of 12 and 22. This was surprising to me, to find that I ended up with the factual average as my personal average. That does mean there was some degree of consistency to my judgements, which could be interpreted as a degree of objectivity.

In terms of average score per characteristic, difficulty had the lowest with 2,6; then entertainment with 2,7; originality with 2,9; craftsmanship with 3,3; consistency with 3,4; and legibility with 3,5. Although all scores only deviate from the theoretical average of 3 with maximum 0,5 points, it was surprising to find that legibility scored slightly higher overall. Part of the reason I included legibility as a characteristic was to measure the degree in which the exhibition requires explanation beyond the works themselves. It's good to see I rated only 15 of 79 exhibitions with one or two stars on this point, as I definitely think this is a problem within art in general. But I guess by measuring I found that it's not as big a problem as I thought it was.
That difficulty is the lowest scoring metric doesn't surprise me however. I defined difficulty as the ability of the exhibition to make think and challenge me intellectually, and while I enjoy many exhibitions, these days its rare that they show me something I can't make sense of. In fact, only one exhibition scored five stars on this subject, which was Philip Metten's solo exhibition at Zeno-X gallery in Antwerp.

Broadly speaking, I rated solo shows at galleries the highest, with an average score of 20. Solo shows at institutions received an average score of 19 and solo shows at museums received the true average of 18. Group shows at institutions scored a slightly below average score of 17, but group exhibitions at museums on average scored a mere 14. This is also the biggest deviation from the norm with 4 points. These low scores for group exhibitions reflect my overall impression that curators aren't very good at making exhibitions and that this is especially true for curators working at museums. In fact, the only group show that scored above average was The insincere charm of things at the Balcony in the Hague.

Some interesting low scores came from shows by Anne Imhof, Jenny Holzer, Simon Denny, Kasper Bosmans, Helen Frankenthaler, Ragnar Kjartansson, and Elmgreen & Dragset. These are all normally considered highly rated artists, if not globally then at least in their respective countries of origin. Yet the shows I saw of them in 2023 apparently weren't exactly up to snuff.
I personally found it interesting that Daan van Golden at Micheline Swaczjer had a below average score as well. That just wasn't a very interesting show with works from an artist I otherwise greatly appreciate.

Of course I also have a top five of shows that I've recorded in the past year.
My top show, with a score of 28, was Tomma Abts at galerie Buchholz in Cologne, followed by Thomas Schütte at De Pont in Tilburg. The latter got there purely on the quality of the works themselves, as the curatorial effort was average at best. Third was Jeff Weber's Image Storage Containers at the CNA in Dudelange. I doubt many people have seen that exhibition, but it was very well put together on all fronts and punching well above its weight.
Fourth and fifth place are actually by the same artist, namely Aglaia Konrad at the FOMU in Antwerp and then later in the year also at Mu.Zee in Ostend. Once again just excellently put together shows that merely faltered a little bit on the entertainment factor.

Only one show actually got the average score of all 3-stars and this was Blank. Raw. Illegible..., curated by Moritz Kung at the Leopold Hoesch Museum. It was a comprehensive group show of 'empty' books and about as average as an exhibition can be. The presentation was adequate enough to be unnoticeable, simply unremarkable in every way possible. For an audience it's often hard to understand books when displayed in glass vitrines, but each book was carefully considered and shown in such a way to be as accessible as it could possibly be. The books on display presented a very broad, thoroughly researched overview and thus for every uninteresting work in the exhibition there was also a gem that got you excited. And as unusual the premise of the exhibition was, it was simultaneously also somewhat obvious. If you want to have a yardstick for what a neutral and average exhibition looks like, that is it. It was spectacular how unspectacular it was.

As a final remark I only found a very weak correlation of 0,28 between time spent in the exhibition and the overall score. The bulk of this number comes from the correlation between the scores for entertainment and for difficulty, with a correlation to time spent of respectively 0,40 and 0,32. All other metrics had a correlation of 0,18 or less. So if you make me laugh or think, I'm going to spend (slightly) more time at your exhibition. 

Keeping track of the exhibitions I've visited like this has been an interesting experiment. I would also say that I've mostly succeeded in my attempt to rate the exhibitions as objectively as possible on each of the six characteristics. When all the scores are added up, each exhibition is found in the quartile that corresponds to my more intuitive and 'unfiltered' opinion of that exhibition. I'm not sure if I will continue to keep track of the exhibitions I will visit in the future, but it's been personally interesting to systematically record one's thoughts and I believe it has given some indication that a more objective rating system for exhibitions is possible by using different metrics than those that are commonly used.