Tag Archives: painting

Spanish cave paintings confirmed to have been made by the Neanderthals

Neanderthals in Europe weren’t the simple brutes they’re often portrayed as being, a new study suggests. It confirms that red ochre markings found in a Spanish cave were made by the Neanderthals and probably used for a symbolic or ritual purpose for thousands of years.

A general view and a close-up of a partly colored stalagmite tower in Cueva de Ardales. Image credits Africa Pitarch Martí et al., (2021), PNAS.

The Cueva de Ardales cave in Málaga, Spain, is one of the most impressive and well-preserved examples of Paleolithic cave paintings in southwestern Europe. More than a thousand different representations have been found here, indicative of the cave being inhabited by many generations of early humans.

One stalagmite here was painted red ochre thousands of years before the emergence of modern humans in Europe, according to a new paper, and offers us a glimpse into the history and culture of the Neanderthals.

Man-made

It was first suggested that Neanderthals painted this stalagmite red in 2018, when an initial dating of the pigment showed it’s at least 64,800 years old. However, the results were contested, and “a scientific article said that perhaps these pigments were a natural thing,” explained co-author Francesco d’Errico for Agence France-Presse. It proposed that the markings were the result of iron oxide (iron) deposited by water infiltrating into the cave.

The new study shows that the deposition and composition patterns in this pigment are not consistent with natural processes. It was most likely applied through splattering (mixed with water) and blowing (in a powdered form).

Furthermore, the authors explain that pigment was repeatedly applied to the stalagmite over time, at least over ten millennia.

“[The findings] support the hypothesis that the Neanderthals came on several occasions, over several thousand years, to mark the cave with pigments,” said d’Errico, of the University of Bordeaux.

But they were likely not art in the way we understand the term. The markings themselves are different even from the cave art made by our ancestors thousands of years ago. Rather, the authors explain, these markings were “result of graphic behaviors intent on perpetuating the symbolic significance of a space.”

While the markings do seem to have been culturally or symbolically significant, we don’t actually know why, or what they meant. Even so, the study showcases how the Neanderthals were not necessarily as simple as we’ve come to think of them. They were capable of manufacturing and using advanced tools, making art, and using language.

The paper “The symbolic role of the underground world among Middle Paleolithic Neanderthals” has been published in the journal PNAS.

The world’s oldest known cave painting in Indonesia shows a chonky wild pig

The lush environment of Indonesia harbors some of the oldest known cave art. Now, it can officially boast having the oldest known cave art. Dated to 45,500 years ago, this prehistoric figurative painting depicts a Sulawesi warty pig — and researchers say there should be more like it in the area.

Dated pig painting at Leang Tedongnge. Maxime Aubert Credit: Maxime Aubert

Sulawesi is an Indonesian island east of Borneo. Rich in lush vegetation and karst environment, it would have been an excellent home for early humans. Unsurprisingly, then, the island has a long history of human occupation, with stone artifacts dating up to 194,000 years ago, possibly from a yet-unidentified ancient human species.

The Leang Tedongne cave, where the painting was discovered, lies in a narrow valley, enclosed by steep limestone cliffs — exactly the type of karstic landscape you’d expect to find caves in. Doctoral Student Basran Burhan came across the painting during 2017 surveys carried out with local authorities and members of the local Bugis community.

The cave is only accessible during the dry season as the valley gets flooded during rainy season. In fact, it’s so inaccessible that Bugis members told researchers the cave had never been seen by Westeners before.

Leang Tedongnge cave. The cave is located at the foot of a limestone karst hill. Credits: Brumm et al / Science Advances.

Measuring 136 by 54 centimeters (53 by 21 inches), the Sulawesi warty pig is painted in a single dark red color. It has a short crest of upright hair and a pair of horn-like warts, which help researchers identify the species of the pig. There are also two hand prints near the pig, as well as two partially preserved pigs, suggesting that it could have been a larger narrative scene.

The painting also features an artistic technique often found in ancient cave paintings, the researchers note in the study.

“It should be noted that the artists portrayed preorbital warts in the so-named twisted perspective. This is a common method of graphical representation in prehistoric art that entails using a single outline profile image of an animal to depict how it appears to an onlooker when observed from different viewpoints.”

“The pig appears to be observing a fight or social interaction between two other warty pigs,” said co-author Adam Brumm.

Sulawesi warty pigs have been hunted for tens of thousands of years in Indonesia, and have even been domesticated in some regions. It’s unsurprising then that these creatures feature prominently in cave art.

The researchers also analyzed a couple of other cave paintings, dating them and identifying the depicted species. The previous oldest cave art was dated from 43,900 years ago, also from Indonesia.

Could be even older

Since the maximum age that can be dated using carbon dating is 50,000 years, the cave painting was dated using another method: uranium dating. However, the team didn’t date the paint itself to prevent any damage, but rather the layer of calcite that formed on top of the painting. This means that the painting itself “could be much older because the dating that we’re using only dates the calcite on top of it,” they say.

Digital tracing of the rock art panel. Image credits: Brumm et al / Science Advances.

But even if the painting dates from so long ago, the people who made it were, by any definition, people. The team believes the artwork was made by Homo sapiens and not another, now-extinct human species like Denisovans (or another unidentified species) but cannot say this for certain at this moment. Regardless of what species made it, they were still people, researchers conclude.

“The people who made it were fully modern, they were just like us, they had all of the capacity and the tools to do any painting that they liked,” he added.

Since the depicted scene also features a couple of handprints, researchers are hoping to get some DNA samples and see what species created the art. In order to produce these handprints, the artists would have had to place their hand on the wall and then spit pigment over it — traces of that may yet be discovered, shedding new light on this ancient episode of human evolution.

The study has been published in Science Advances.

Stone pattern.

Painted rock points to higher cognitive function in humans 73,000 years ago

A painted rock shows that humans tried their hand at symbolism as early as 73,000 years ago, pointing to the roots of modern cognition patterns.

Stone pattern.

Image credits Christopher S. Henshilwood et al., 2018, Nature.

International researchers report discovering the oldest evidence of abstract drawing to date. The artifact in question is a fragment of polished rock painted with a crosshatch pattern of nine fine lines, unearthed from a 73,000-year-old archaeological stratum at the Blombos Cave in South Africa.

“Do you do portraits, too?”

It’s not easy determining symbolism from art when dealing with some of the earliest graphic productions humanity has ever created. The main difficulty lies in determining whether the splotches of pigment were applied deliberately or not. After intentionality is established, the next step is to determine whether the images you’re dealing with are doodles or storytelling crutches, or whether they held particular meaning.

Needless to say, across the huge divides of time and culture that separate us from our ancestors, both points can be very tricky to handle.

The oldest known sample of art we’ve found before now is the shell of a freshwater mussel engraved with a zigzag pattern discovered in Tirnil, Java, in a 540,000-year-old archaeological layer. Decorated trinkets discovered in several archeological sites in Africa, likely used for personal adornment, have been dated to roughly 70,000 years ago.

Pattern.

A rendition of the crosshatched pattern seen on the fragment of stone.
Image credits Christopher S. Henshilwood et al., 2018, Nature.

Still, art does not necessarily a symbol make. A symbol is a mark, sign, or word that represents an idea, another object, or a relationship. While the main trait of art is beauty or its ability to encapsulate an emotional message, a symbol is, foremost, an abstraction. As such, accurately telling apart art and symbolism is very important for anthropology. Both art and symbols “are a prime indicator of modern cognition and behavior”, the team writes — the latter especially so, since abstraction requires that extra bit of intellectual brawn to handle.

Well, we have new evidence pointing to the roots of abstract thinking at least 30,000 years earlier than previously discovered works suggested.

Abstrart

The artifact, detailed by an international team that includes scientists from Norway, France, South Africa, and Switzerland, is a fragment of siliceous rock (silcrete) adorned with nine fine lines in a crosshatch pattern. It was found during excavations at the Blombos Cave, South Africa, in a 73,000-year-old archeological stratum. According to the team, the lines were drawn using an ocher (the iron ore from which the eponymous color is derived) pencil.

Ocher and silcrete implements.

Ocher and silcrete implements used in the reconstruction efforts.
Image credits Christopher S. Henshilwood et al., 2018, Nature.

Determining whether the pattern was deliberately drawn fell primarily on the shoulders of the team’s French members, who have a background in the chemical analysis of pigments.

They started by trying to reproduce the lines through various techniques — an approach known as experimental or experiential archeology, as it relies on direct experience gained from experimentation — that were available to the people living around the cave at the time. These included whittling ocher fragments to a point or an edge to see which shape better recreates the lines, as well as applying watery solutions of ocher powder using brushes.

Closeup original.

Closeup of the original markings.
Image credits Christopher S. Henshilwood et al., 2018, Nature.

They then compared the lines against their ancient counterparts from a microscopic, chemical, and tribological (the science of friction and wear) standpoint. According to the team, the lines were intentionally drawn with a pointed ocher implement (akin to a pencil). As such, the pattern represents the earliest known abstract drawing to date.

Closeup reconstruction

Closeup of the reconstructed lines.
Image credits Christopher S. Henshilwood et al., 2018, Nature.

With intentionality established, the next step was to decide whether the team was looking at a symbol or just pretty doodles. This step was surprisingly simple, however. Blombos Cave is the site of an ongoing excavation by teams from the University of Bergen (Norway) and the University of Witwatersrand (South Africa) that began in 1991. Over the years, many other objects with symbolic markings — including ocher fragments that feature very similar crosshatched engraving — were uncovered in the same archaeological stratum in which the present artwork was discovered.

The team writes that by using various techniques to produce similar patterns on different materials suggests that the marks serve a symbolic function.

The paper “An abstract drawing from the 73,000-year-old levels at Blombos Cave, South Africa” has been published in the journal Nature.

Wilting away: Van Gogh’s legendary sunflowers are turning brown

Some of the world’s most famous and cherished photos might be losing their colors: due to Van Gogh’s light-sensitive paint, his famous sunflowers might fade to brown.

After 150 years of blossoming, Van Gogh’s flowers might be wilting away.

The Van Gogh Museum in Amsterdam has some bad news: Van Gogh’s most famous paintings may be losing some of their color. Using a newly pioneered technique, they found that the sunflowers’ trademark yellow is slowly turning brown. The reason for this is because Van Gogh used a light-sensitive yellow paint.

So far, the change isn’t visible to the naked eye, but the customized X-ray showed that the yellow used in many of the sunflower paintings is set to lose its remarkable vibrancy.

“It is very difficult to say how long it would take for the change to be obvious and it would depend a lot on the external factors,” said Frederik Vanmeert, a materials science expert at the University of Antwerp, who was part of the research team.

“We were able to see where Van Gogh used the more light-sensitive chrome yellow, the areas that the restorers should look out for over time for discolouration … We were also able to see that he used emerald green and a red lead paint in very small areas of the painting which will become more white, more light, over time.”

However, not all of the paintings will degrade equally — Van Gogh used two different yellow chrome pains, and only one of them is particularly sensitive to light. In order to determine this, researchers carried out a painstakingly detailed X-ray mapping. The technique is so detailed that researchers were able to obtain a level of resolution that allowed them to see how the paint crystallites aligned along the direction of Van Gogh’s brush strokes

It’s not the first time something like this has been reported. Just last year, a different study found that LED lights may be accelerating decoloration in Van Gogh’s paintings. However, Soraa, an LED manufacturer in California, contends that Xenon lamps, not LED lamps, were used in the research, and that “Xenon lamp spectra are vastly different than those of white-emitting LEDs for illumination.”

The museum in Amsterdam, like many other art museums, has already taken steps to prevent degradation of its paintings: five years ago, they significantly reduced the lighting in the presentation rooms, but even so, some paintings (like Van Gogh’s) seem to be affected. The head of collection and research at the museum, Marije Vellekoop, said they are closely following the results of the study and will decide on necessary measures.

“At the moment, we are processing all the research results of this iconic painting, after which we determine how we will pay further attention to discolouration in our museum. We know that the discoloured pigment chrome yellow has been used a lot by Van Gogh, we assume that this has also been discoloured in other paintings.”

New AI tells masterpieces from forgeries by only looking at brush strokes

AIs might not know much about art, but they can easily tell apart one style from the other — even when they’re terribly similar.

AI could see whether a painting is fake or not. Credits: Pexels.

Identifying forgeries is hard, time-consuming, and expensive, but we need it more than ever. The art world is full of forgeries. Recently, a supposed Da Vinci painting sold for $450 million, although suspicions loomed that it might be a fake. The problem is, humans have a hard time telling apart real art from fakes. In most cases, a trained eye will catch small details, identifying tells that confirm or infirm authenticity. If you want a more thorough confirmation, you might take the art piece in a laboratory for infrared spectroscopy, radiometric dating, gas chromatography, or a combination of such tests. All this takes a lot of time, money, and effort. But an Artificial Intelligence (AI) needs none of this.

In a new paper, researchers from Rutgers University and the Atelier for Restoration & Research of Paintings in the Netherlands broke down the style of different artists, by analyzing their strokes. They developed a recurrent neural network (RNN) which learned what features were important for what artist, and then used said traits for identification.

“We designed and compared different handcrafted and learned features for the task of quantifying stroke characteristics,” the study reads. “We also propose and compare different classification methods at the drawing level. We experimented with a dataset of 300 digitized drawings with over 80 thousands strokes. The collection mainly consisted of drawings of Pablo Picasso, Henry Matisse, and Egon Schiele, besides a small number of representative works of other artists. The experiments shows that the proposed methodology can classify individual strokes with accuracy 70%-90%, and aggregate over drawings with accuracy above 80%, while being robust to be deceived by fakes (with accuracy 100% for detecting fakes in most settings).”

The AI especially analyzed the strength along a stroke — how hard and in what way the artist was pushing the brush against the canvas. That is impossible for a human to analyze since it requires a visual precision that the human eye is just not capable of. However, there is also a downside: the AI only works when the strokes are clearly visible. When the painting has aged and strokes have faded out, accuracy declines significantly.

They only focused on a few painters, and the results aren’t perfect, but as a proof of concept, the AI showed it is more than capable. If anything, it could be used alongside more conventional techniques for an extra confirmation, or by itself to give solid indications about authenticity. The RNN could also be enhanced to include more painters and other artistic tells.

Now, the only question is, how long until someone will train an AI to trick this AI?

Journal Reference: Ahmad Elgammal et al. Picasso, Matisse, or a Fake? Automated Analysis of Drawings at the Stroke Level for Attribution and Authentication. arXiv:1711.03536v1

Gecko feet may help keep art clean

Geckos may be giving art conservationists an unexpected hand – a new way of keeping art clean.

Close-up of the underside of a gecko’s foot as it walks on vertical glass. Image via Wikipedia.

This doesn’t mean we’ll be letting hordes of geckos run rampant through the Louvre because that’s not how science works (though it could create a lovely Disney scene). Instead, researchers took inspiration from geckos, designing a material that can collect the smallest motes of dust from a painting without damaging it. Needless to say, this could be very useful.

“Acrylic paints are incredibly porous, so anything you’re putting on the surface could get into the pores, and then work from the insides of the pores to soften the paints,” Cindy Schwartz, an art conservator at Yale said.

Dust is a very big problem when it comes to paintings. If dust paintings are bigger than 10 micrometers, you can remove them without big problems, usually through some type of jet. But even so, there is a risk of damaging the painting, and if they’re smaller, it gets even more difficult. There are other removal methods, some more complex than others, but all have their drawbacks.

This new solution could be deceptively simple. Hadi Izadi, a postdoctoral associate and the paper’s lead author, created a material which looks much like an ordinary plastic sheet but is actually a non-sticky, elastic polymer called polydimethylsiloxane (PDMS).

Microscopic image of silica dust particles lifted by micropillars, 50 micrometers in diameter. (Credit: Vanderlick Lab)

If you would look at PDMS under a microscope, it looks like a sheet with millions of columns; there are different sizes of columns for different sizes of dust specs. Interestingly, gecko feet are designed specifically to not have things stick to them – and this is why this material is so good. It has almost no interaction with the substrate (the painting), but if their size is just right, it produces enough electrostatic energy to attract the dust specs. Therefore, it can clean the paintings without damaging the painting at all.

“Dust is something at the nanometer level,” Vanderlick says. “And there’s a lot of interesting thin film, surface, and interfacial physics associated with the preservation of art.”

Journal Reference: Removal of Particulate Contamination from Solid Surfaces Using Polymeric Micropillars.

The new Rembrandt: Computer creates new “Rembrandt painting”

Rembrandt Harmenszoon van Rijn is one of the most talented and famous artists in human history. It’s been almost four centuries since he created his unique masterpieces. Now, a team of artists, researchers and programmers wanted to see if they can create a new Rembrandt painting – through a computer algorithm.rembrandt“We examined the entire collection of Rembrandt’s work, studying the contents of his paintings pixel by pixel. To get this data, we analyzed a broad range of materials like high resolution 3D scans and digital files, which were upscaled by deep learning algorithms to maximize resolution and quality. This extensive database was then used as the foundation for creating The Next Rembrandt.”

The algorithm analyzed patterns in Rembrand’s works, such as eye shape and color scales. The goal was to create a new work while mirroring Rembrand’s style as much as possible. They chose a portrait as the main theme for the “painting”, opting for a Caucasian male between the ages of 30 and 40, with facial hair, wearing black clothes with a white collar and a hat, facing to the right. Rembrandt created many similar works.

Emmanuel Flores, director of technology for the project declared:

“We found that with certain variations in the algorithm, for example, the hair might be distributed in different ways,” explained Mr Flores.

But ultimately, not he nor anyone else chose the final characteristics of the painting. They just implemented the algorithm, and the algorithm decided on the ultimate appearance of the portrait.

After the image was created, it was 3D-printed to give it the same texture as an oil painting. Even the way Rembrandt used brushstrokes was replicated in the 3D printing.

“Our goal was to make a machine that works like Rembrandt,” said Mr Flores. “We will understand better what makes a masterpiece a masterpiece.”

However, he added, “I don’t think we can substitute Rembrandt – Rembrandt is unique.”

The painting will be featured on an exhibition in the UK, but no place or date have been made public.

The two-year project, entitled “The Next Rembrandt“, was a collaboration between Microsoft, financial firm ING, Delft University of Technology and two Dutch art museums – Mauritshuis and Rembrandthuis.

Left: Van Gogh painting “Wheat Stack under a Cloudy Sky” (Kröller-Müller Museum, Netherlands). The paint sample area is indicated by a white circle. Upper right: Detail of the painting in the sample area, lower right: Detail of the paint sample (picture: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

Why Van Gogh’s paintings are fading to white

Belgian scientists have revealed a refined explanation for the chemical process that’s currently degrading Vincent van Gogh’s famous paintings, which are losing their bright red. Like other old paintings, van Gogh’s works are losing their saturated hue because of the interaction between red led and light. Using sophisticated  X-ray crystallographic methods, the researchers identified a key carbon mineral called plumbonacrite in one of his paintings, which explains the process even better.

Left: Van Gogh painting “Wheat Stack under a Cloudy Sky” (Kröller-Müller Museum, Netherlands). The paint sample area is indicated by a white circle. Upper right: Detail of the painting in the sample area, lower right: Detail of the paint sample (picture: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

Left: Van Gogh painting “Wheat Stack under a Cloudy Sky” (Kröller-Müller Museum, Netherlands). The paint sample area is indicated by a white circle. Upper right: Detail of the painting in the sample area, lower right: Detail of the paint sample (picture: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

All paints are made up of three key parts: the vehicle (usually water), the pigment (the stuff that gives matter color – usually mined from the earth in the form of clay or mineral or even plants, but also synthetic form), and a binder (otherwise you’d just have colored water – typically chalk is used). Red lead (minium, or lead (II,IV) oxide) is a lead oxide whose composition is Pb3O4 and whose color varies over time. It’s been a favorite pigment for thousands of years. In fact, it can still be found in the old cave paintings some 40,000 years old. Of course, it degrades over time darkening as the red lead pigment is converted to plattnerite (beta-lead dioxide) or galena (lead sulfide). At other times, the color will lighten or bleach due to the conversion of red lead to lead sulfate or lead carbonate.

A team led by Koen Janssens at the University of Antwerp investigated what makes van Gogh’s paintings turn white by taking a microscopic sample from “Wheat Stack under a Cloudy Sky”, one of his famous work, and subjecting it to crystallographic analysis. X-ray powder diffraction mapping and tomography techniques were employed to determine the spatial distribution of the various crystalline compounds found throughout the sample. They eventually found an unexpected compound, the very rare lead carbonate mineral called plumbonacrite (3 PbCO3·Pb(OH)2·PbO).

“This is the first time that this substance has been found in a painting from before the mid twentieth century,” reports Frederik Vanmeert, first author of the paper. “Our discovery sheds new light on the bleaching process of red lead.”

Considering this latest finding, the Belgian researchers proposed a chemical reaction pathway of the red lead under the influence of light and CO2, which ultimately altered the pigment and caused a color change in the painting. As light hits the paint (red lead and other pigments), the incoming energy causes electrons to move from the valance band to the conducting band in red lead, which is a semi-conductor. This reduces the red lead to PbO, which reacts with other products formed by the reaction of CO2 from the air with the degrading binding medium. Ultimately, this forms plumbonacrite  as an intermediate that is converted to hydrocerussite and then to cerussite (lead carbonate). All these products are white, hence the lower saturation. The findings were reported in  Angewandte Chemie.

Art aficionados shouldn’t fret too hard, though. Van Gogh’s paintings are still marvelous, despite more than a hundred years since the Dutch painter made his first stroke on the canvas. Museums give great care and employ special conservation methods to keep the old masters’ work bright and vibrant for hundreds of years to come.