Category → physics
This is a guest blog post from Stu Borman, a C&EN senior correspondent for science, technology & education.
A French-based research team recently had a rare opportunity to get to the heart—quite literally—of some 12th century European history.
Using a battery of scientific equipment, they took a closer look at how the heart of English king Richard I was preserved for posterity.
Also known as Richard the Lionheart because of his military prowess, Richard I was king of England from 1189 to 1199.
He led a Crusade to the Holy Land in 1190, but the mission failed to take Jerusalem, its main objective.
On the way back home he was imprisoned by an Austrian duke and the German emperor and then only released after payment of what was literally a king’s ransom. Continue reading →
In the 1990s the market for photos exploded. As snapshots started selling for millions of dollars, sham photos also slipped into the fray before the art world had any way to authenticate originals.
And so cultural heritage researchers had to play some serious catch-up, and quickly.
That’s the gist of my recent cover story on photo conservation. It explores how two fraud cases helped turn the field from a niche research area to a mature science.
And as always happens when reporting, many cool tidbits didn’t fit in to the final piece… In this case, the pivotal role eBay played to help researchers develop ways to catch fakes.
But first, a bit of background on photo fraud:
In the photo market, people will pay more money for an image when it was actually printed on paper by the photographer himself or herself. The price can also increase when the print is older.
So, for example, the Getty Conservation Institute’s Art Kaplan told me that an Ansel Adams photograph printed in the 1920s can sell for hundreds of thousands of dollars, while the exact same photograph printed a few decades later (say, the 1970s) can sell for just tens of thousands of dollars. Continue reading →
These may look like real fossils, but they are actually perfect plastic replicas of 2 million-year-old whale skeletons made using a 3D printer.
This printing technology, which can create 3D versions of objects as diverse as a guns or the brain of a man with no memory, was hyped last week by President Obama when he said that 3D printing “has the potential to revolutionize the way we make almost everything.”
The technology certainly saved the day for Smithsonian paleobiologist Nick Pyenson.
Pyenson had been finishing up a research trip in Chile in 2011 when he decided to check out a local highway construction site in the Atacama Desert where workers had supposedly uncovered dozens and dozens of whale skeletons.
“I didn’t really believe the rumors at first,” Pyenson says. But when he arrived, “It was unlike anything I’d ever seen.” Pyenson described the experience at the American Association for the Advancement of Science meeting in Boston.
Local museum officials were racing to dig out the skeletons before highway workers paved over the area, Pyenson says. Although the skeletons clearly needed to be removed, a problem with removal is that spatial information about different constellations of fossilized bones is then lost. Continue reading →
So you’d think that making a replica of a Rembrandt might be frowned upon by the art world, but this copy of “An old man in military costume” has full approval of its owners.
In fact, the folks at the Paul Getty Museum in LA, asked their own intern to replicate the masterpiece as well as the hidden painting beneath it.
It seems that there’s a pretty good reason for making the copy, or “mock-up” as the researchers call it.
For years, museum researchers have known that there’s another painting beneath the military portrait. But they’ve had a tough time getting more than just a faint whiff of the image hidden below using standard analytical methods.
Over the past few years, a new technique called scanning macro X-ray fluorescence (MA-XRF) has proven itself useful for uncovering hidden paintings on canvases by Van Gogh, Goya and others.
The question is whether MA-XRF would work for Rembrandt’s military portrait. And specifically, whether a portable X-ray device was powerful enough to do the trick or whether the painting should travel to a more a powerful synchrotron X-ray source, such as in Hamburg (DESY) or at Brookhaven National Labs in New York.
It comes down to the fact that museums don’t like shipping valuable and fragile art around the world unless it’s absolutely necessary.
Enter intern Andrea Sartorius (who I momentarily hoped was a descendent of the 17th century Croatian weight-loss fanatic & innovator, Sanctorius Sanctorius. Sadly the names are not quite the same.)
Anyway, Sartorius painted a copy of the original Rembrandt using the same kind of pigments and binder that he would have used, and she included another portrait below the military one.
Then the copy was shipped around the world to be analyzed using X-rays from the various synchrotron sources and from the portable device. Turns out it’s worth the trip to more snazzy X-ray sources if you want to see the hidden painting below. The team argues in this paper that transporting the Rembrandt to a synchrotron facility is actually “useful and relevant.”
The paper’s lead researcher, Matthias Alfred, praised the mock-up: “It is the first time that a painting was reproduced in such an elaborate way for these tests.” It seems that experiments on mock-ups help museum staff decide whether sending expensive art to outside labs for analysis is worth the risk and effort.
And that, my friends, is how a fake Rembrandt can sometimes be a good thing.
Fifty one years ago today, communist officials in East Germany erected the Berlin Wall to stop the exodus of their citizens to capitalist West Berlin.
The 155-km barricade came down 28 years later in 1989, and since then, every self-respecting tourist shop in town sells chunks of spray-painted concrete to anyone seeking a piece of 20th century history.
Today’s price for a chunk of the Wall, as determined during my lunch-time walk to the local tourist shop from my office at the East-West border in Berlin: €4.95 or about $6.10.
You can get a better deal if you buy these cellophane-wrapped mementos from street vendors.
A few years ago, the rather ample supply of German history for sale got Ralf Milke, a geochemist at Berlin’s Free University, wondering whether he could find a way to authenticate pieces of the Wall. Continue reading →
How do museums deal with radioactive artifacts?
The question first popped in to my head when I was standing at the entrance of the Mütter Museum in Philadelphia, looking at a device built by Pierre Curie in the 1880s to measure radioactivity.
Given that the device—a piezoelectric quartz electrometer—had spent decades measuring radioactivity, I guessed it probably was or had been radioactive itself.
Then it occured to me that the devices used by Pierre and Marie Curie aren’t the only kind of radioactive artifacts found in museum collections.
German chemist Martin Heinrich Klaproth discovered uranium in 1789, and by 1830 the radioactive element was being used heavily as a yellow-green colorant in all sorts of glassware (before people even knew what radioactivity was).
By the early 20th century, uranium oxide was used to color the incredibly popular orange-red ceramic Fiesta tableware favored by Andy Warhol and many others. And radium-226 was used to paint watches, aircraft gauges, door knobs, religious icons, light switches and even chamber pots so that they glowed in the dark.
Radioactivity also became a health fad. Look no further than the “Lifetime Radium-Vitalizer Water Jar,” from the 1920s, which added radiation to water by means of a chunk of uranium ore at the bottom of the vessel.
In addition to quack health products, radioactive artifacts are sometimes natural history museum minerals as well as relics and equipment from the Manhattan project and all subsequent nuclear testing.
Since we are all exposed to low-levels of radiation daily–heck, our own bones emit radiation to those around us–the issue is whether a particular artifact emits enough radiation to present a health hazard to museum staff and the public.
Continue reading →
One of the coolest talks I saw at the ICOM-CC conference in Lisbon last week came from Jens Stenger, a conservation scientist at the Harvard Art Museums in Boston. He had the tricky task of figuring out what to do about five paintings by Mark Rothko in the museum’s collection that were so damaged from sunlight exposure that crimson paint on the canvas had turned to blue.
If just a tiny corner of the paintings were light damaged, museum staff might have considered retouching the artwork with a little paint. But a massive fraction of the massive panels were seriously light-damaged.
And these days the trend in art conservation is to minimize interventions on art, especially contemporary art. So a team of curators, conservators and scientists decided that, “repainting was NOT the way to go,” Stenger said.
But everyone thought museum visitors would want to know how the artwork had looked before the light damage. So what to do?
The solution Stenger came up with is pretty cool: Figure out the exact coloration of the originals. Display the artwork as is, but set up a digital light projector that can cast an image on to the canvases. This projected image temporarily makes the paintings appear as they did when Rothko finished them in 1963. Switch off the projector and the paintings are returned to their current-day states. It’s effectively restoration with an undo button. (And as an aside, the amount of light delivered by the projector is not sufficient to continue to harm the painting.)
Continue reading →
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.
Continue reading →