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Archive → July, 2011

A Short Summer Sabbatical

A painting by Daphne Mennell called Spirit Lake, sort of. Courtesy of the artist.

This post comes from Whitehorse, in the Yukon (that’s in Canada, folks), where I’m about to embark on a two-week, 400-km canoe trip along an old gold rush route to Dawson City.

This means Artful Science will have a two week hiatus while I avoid getting eaten alive by mosquitoes and bears.

I thought I’d say au revoir with an image from Yukon-based artist, Daphne Mennell.

See y’all in August!

Plastics Denial Syndrome

Dutch artist Madeleine Berkhemer uses stockings in her art, which are made of nylon and spandex. Photo Courtesy of Berkhemer.

Sometime during the 1960s, artists en masse began using plastics to make art–a trend that continues today.

The problem is that many plastic polymers have a shelf life of just a decade or so, after which they begin to crumble or crack. Consider an old rubber band or a plastic bottle left out in the sun.

And just as bisphenol A leaches out of baby bottles and into the surrounding liquid, many of the components of plastic-based art seep out of the work, causing all sorts of unpleasant consequences (details below).

Furthermore, the short lifespan of plastic art is at odds with the fact that most museums want to buy art that lasts centuries or at least decades… not years.

Yet in the 1970s, 80s and early 90s, just as plastic sculptures and designer furniture were pouring in to museum and gallery collections, staff conservators were collectively sticking their heads in the sand about the inherent vulnerability of these objects… I mean, even though plastics have short lifespans, there are ways to extend them. But conservators weren’t acknowledging that plastics were problematic.

It’s come to be known as “the plastics denial syndrome” and thankfully it’s now over, says Yvonne Shashoua, a conservation scientist at the National Museum of Denmark, in Copenhagen. Shashoua features heavily in an article I just wrote about how plastics are a serious problem child for museum staff and what can be done to improve some pretty impressive bad behavior.

Yvonne Shashoua cares for a 1970s crash test dummy that is literally weeping plasticizer. Photo Courtesy of Shashoua.

Case in point: the phthalate plasticizer added to make PVC (polyvinyl chloride) maleable has a tendency to leach out, so much so that small pools of the plasticizer collect in and around the art. These plasticizer puddles are not precisely aesthetically pleasing, they attract dust and actually the loss of the plasticizer destabilizes the plastic making it vulnerable to cracking.

Then there’s this more nepharious example: Acidic gases percolate away from plastic objects made of cellulose acetate and then corrode nearby metals and textiles. For this reason conservators call cellulose acetate “the malignant plastic.”

Cases like these forced conservators to take the degradation of plastics seriously. Check out the longer article to find out what museum staff are now doing to keep plastic art and artifacts alive and as well-behaved as possible.

Where Oh Where Were The Dead Sea Scrolls Written?

A Dead Sea Scroll text. Credit: Newscom.

In the late 1940s and early 50s, nearly 1000 manuscripts were found in caves along the banks of the Dead Sea at a site called Khirbet Qumran. The so-called Dead Sea Scroll texts, which include the oldest known versions of the Hebrew Bible as well as other important ancient writings, have long provided fodder for all sorts of academic research and debate.

One serious point of contention is whether the manuscripts were all written at Khirbet Qumran, or whether the caves were simply a library–a grotto-like repository.

Figuring out an answer to this question with science but without harming the precious documents is a tall order, but one that may be filled using a new technique developed by a team at the Technical University in Berlin, led by Ioanna Mantouvalou.

It turns out that the Dead Sea Scroll documents were penned on a real potpourri of materials, including copper, papyrus (a plant-based paper) and parchment (animal skin). Mantouvalou and her colleagues decided to focus on the provenance of the parchment-based writings because these form the majority of the Dead Sea Scroll collection.
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Vincent Van Gogh’s Last Months

Vase with Fifteen Sunflowers. Credit: Wikimedia commons.

In the last year of Vincent van Gogh’s life, as his mental illness escalated and before his suicide in 1890, the Dutch impressionist painter voluntarily committed himself in to two French hospitals.

The isolation didn’t thwart van Gogh’s productivity–he painted some 200 paintings during the 15 months he spent in treatment. Nor did the isolation prevent him from experimenting with trendy new pigments bequeathed by the industrial revolution, such as chrome yellow, which he used to paint his famous sunflower series. This pigment fell out of favor by the 1950s when its lead and chromate make-up was found to be toxic.

Unfortunately, chrome yellow and other then-trendy pigments degrade if they are exposed to light. For example, the degradation turns the bright yellow pigment into a rather sad looking green color. Earlier this year Koen Janssens, at the University of Antwerp, in Belgium, explained the chemistry behind this degradation, by using X-ray spectroscopy to show that when the chromium in the yellow paint was subjected to too much light, it went from a hexavalent state to a trivalent state. Many media outlets reported on the discovery, including C&EN

and Newscientist .

The MOLAB van on the road in Greece. Credit: MOLAB.

Now Janssens has turned his attention to the so-called red lake pigments that van Gogh used in paintings during the 15 months of his life. Janssens recruited the help of MOLAB, a group of roaming scientists who travel around Europe with high tech, portable equipment. Their gear can help him study light degradation of the valuable art without harming it.

Last week, the MOLAB team, aka CHARISMA, drove 1500km from Perugia, Italy, to the Kröller-Müller Museum, in Otterlo, in the Netherlands. The Kröller-Müller has 22 paintings from van Gogh’s last months of life, and with the help of the mobile lab, the researchers can study the red pigment degradation without moving or harming the artwork.

Hopefully the new research will clarify the chemistry of the paint breakdown so that further degradation of van Gogh’s work can be avoided.

I can’t help thinking about the tragic irony of it all… that as van Gogh’s mental health was rapidly deteriorating, he was expressing himself using paint that was itself unstable.

Jackson Pollock Physics

Untitled, ca. 1948-49 by Jackson Pollock. Credit: Provided by Harvard University.

When Jackson Pollock made his art, he’d lie a canvas on the floor. Then he’d use a stick or trowel to drip, splatter or coil the paint on the canvas.

Some critics thought Pollock’s quirky, controversial style made the paintings look like a mop of tangled hair. Others have dropped millions of dollars to buy Pollock’s work, calling him the best American artist of the 20th century. Perhaps it was Pollock’s reliance on gravity and paint viscosity, but his style has also drawn the attention of physicists, whose theories about his work have ignited some controversy of their own. More on that in a moment.

But first, the newest scientific take on Pollock: Physics Today recently described research by Harvard physicist L. Mahadevan and colleagues who used fluid physics to study Pollock’s style. The researchers wanted to understand how Pollock employed gravity and paint of varying viscosities to make coils, splashes and spots on the canvas.

Among other things, Mahadevan’s team “demonstrated mathematically that the only way Pollock could create such tiny looping, meandering oscillations was to hold his brush or trowel high up off the canvas and let out a flow of paint that narrowed and sped up as it fell. To create tiny loops rather than waves, he likely moved his hand slowly, allowing physics to coauthor his art.”

What’s interesting to me is that the fluid physics used to study Pollock’s art was only developed after Pollock was already finished making his masterpieces. Pollock started doing his trademark paintings in the 1940s. Physicists started working out fluid dynamics in the 1950s and 60s. In other words, Pollock’s use of fluid dynamics to make art predates the ability of physicists to mathematically model the same processes.

Pollock was ahead of his time in more ways than one.
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