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Science Tuesday - Twins, the Absurd, and artistic forensics
Q & A: Twins and Fingerprints
By C. CLAIBORNE RAY, The New York Times, October 6, 2009
Q. Why do identical twins have different fingerprints? Why do we have fingerprints to begin with?
A. The probable answers to both questions are related to the minute differences in the mechanical forces each developing fetus experiences in the uterus as its cells proliferate.
Researchers have found that identical twins have a very high correlation of loops, whorls and ridges, but a review study last year in Circulation Research examining how complex structures like the circulatory system develop says that “the detailed ‘minutiae’ — where skin ridges meet, end or bifurcate — are different even between identical twins.” Even twins that develop from one zygote occupy different positions in the womb, and the variations are enough to make a difference.
At the crucial stage of development, the study explains, ridges are thought to form as compressive stresses develop in the dermal cell layer of the skin, sandwiched between the epidermis and the subcutaneous tissue. “Like the buckling of land masses under compression,” the study continues, regular ridges form to relieve the stress.
Where the skin is flat, the ridges are parallel; but primates have raised pads on their fingertips at this stage, so the ridges form along lines of equal stress. “Surrounding the highest point of the raised pad,” the study says, “ridges form in concentric circles.” Meanwhile, the pads are regressing, but where they remain high longer, ridges form whorls. Pads that have largely regressed give rise to a simple arch pattern. Where the processes of ridge formation and pad regression overlap, an intermediate loop pattern results.
Mind: How Nonsense Sharpens the Intellect
By BENEDICT CAREY, The New York Times, October 6, 2009
In addition to assorted bad breaks and pleasant surprises, opportunities and insults, life serves up the occasional pink unicorn. The three-dollar bill; the nun with a beard; the sentence, to borrow from the Lewis Carroll poem, that gyres and gimbles in the wabe.
An experience, in short, that violates all logic and expectation. The philosopher Soren Kierkegaard wrote that such anomalies produced a profound “sensation of the absurd,” and he wasn’t the only one who took them seriously. Freud, in an essay called “The Uncanny,” traced the sensation to a fear of death, of castration or of “something that ought to have remained hidden but has come to light.”
At best, the feeling is disorienting. At worst, it’s creepy.
Now a study suggests that, paradoxically, this same sensation may prime the brain to sense patterns it would otherwise miss — in mathematical equations, in language, in the world at large.
“We’re so motivated to get rid of that feeling that we look for meaning and coherence elsewhere,” said Travis Proulx, a postdoctoral researcher at the University of California, Santa Barbara, and lead author of the paper appearing in the journal Psychological Science. “We channel the feeling into some other project, and it appears to improve some kinds of learning.”
Researchers have long known that people cling to their personal biases more tightly when feeling threatened. After thinking about their own inevitable death, they become more patriotic, more religious and less tolerant of outsiders, studies find. When insulted, they profess more loyalty to friends — and when told they’ve done poorly on a trivia test, they even identify more strongly with their school’s winning teams.
In a series of new papers, Dr. Proulx and Steven J. Heine, a professor of psychology at the University of British Columbia, argue that these findings are variations on the same process: maintaining meaning, or coherence. The brain evolved to predict, and it does so by identifying patterns.
When those patterns break down — as when a hiker stumbles across an easy chair sitting deep in the woods, as if dropped from the sky — the brain gropes for something, anything that makes sense. It may retreat to a familiar ritual, like checking equipment. But it may also turn its attention outward, the researchers argue, and notice, say, a pattern in animal tracks that was previously hidden. The urge to find a coherent pattern makes it more likely that the brain will find one.
“There’s more research to be done on the theory,” said Michael Inzlicht, an assistant professor of psychology at the University of Toronto, because it may be that nervousness, not a search for meaning, leads to heightened vigilance. But he added that the new theory was “plausible, and it certainly affirms my own meaning system; I think they’re onto something.”
In the most recent paper, published last month, Dr. Proulx and Dr. Heine described having 20 college students read an absurd short story based on “The Country Doctor,” by Franz Kafka. The doctor of the title has to make a house call on a boy with a terrible toothache. He makes the journey and finds that the boy has no teeth at all. The horses who have pulled his carriage begin to act up; the boy’s family becomes annoyed; then the doctor discovers the boy has teeth after all. And so on. The story is urgent, vivid and nonsensical — Kafkaesque.
After the story, the students studied a series of 45 strings of 6 to 9 letters, like “X, M, X, R, T, V.” They later took a test on the letter strings, choosing those they thought they had seen before from a list of 60 such strings. In fact the letters were related, in a very subtle way, with some more likely to appear before or after others.
The test is a standard measure of what researchers call implicit learning: knowledge gained without awareness. The students had no idea what patterns their brain was sensing or how well they were performing.
But perform they did. They chose about 30 percent more of the letter strings, and were almost twice as accurate in their choices, than a comparison group of 20 students who had read a different short story, a coherent one.
“The fact that the group who read the absurd story identified more letter strings suggests that they were more motivated to look for patterns than the others,” Dr. Heine said. “And the fact that they were more accurate means, we think, that they’re forming new patterns they wouldn’t be able to form otherwise.”
Brain-imaging studies of people evaluating anomalies, or working out unsettling dilemmas, show that activity in an area called the anterior cingulate cortex spikes significantly. The more activation is recorded, the greater the motivation or ability to seek and correct errors in the real world, a recent study suggests. “The idea that we may be able to increase that motivation,” said Dr. Inzlicht, a co-author, “is very much worth investigating.”
Researchers familiar with the new work say it would be premature to incorporate film shorts by David Lynch, say, or compositions by John Cage into school curriculums. For one thing, no one knows whether exposure to the absurd can help people with explicit learning, like memorizing French. For another, studies have found that people in the grip of the uncanny tend to see patterns where none exist — becoming more prone to conspiracy theories, for example. The urge for order satisfies itself, it seems, regardless of the quality of the evidence.
Still, the new research supports what many experimental artists, habitual travelers and other novel seekers have always insisted: at least some of the time, disorientation begets creative thinking.
Findings: A High-Tech Hunt for Lost Art
By JOHN TIERNEY, The New York Times, October 6, 2009
If you believe, as Maurizio Seracini does, that Leonardo da Vinci’s greatest painting is hidden inside a wall in Florence’s city hall, then there are two essential techniques for finding it. As usual, Leonardo anticipated both of them.
First, concentrate on scientific gadgetry. After spotting what seemed to be a clue to Leonardo’s painting left by another 16th-century artist, Dr. Seracini led an international team of scientists in mapping every millimeter of the wall and surrounding room with lasers, radar, ultraviolet light and infrared cameras. Once they identified the likely hiding place, they developed devices to detect the painting by firing neutrons into the wall.
“Leonardo would love to see how much science is being used to look for his most celebrated masterpiece,” Dr. Seracini said, gazing up at the wall where he hopes the painting can be found, and then retrieved intact. “I can imagine him being fascinated with all this high-tech gear we’re going to set up.”
Dr. Seracini was standing in the Palazzo Vecchio’s grand ceremonial chamber, the Hall of 500, which was the center of Renaissance politics when Leonardo and Michelangelo were commissioned to adorn it with murals of Florentine military victories. On this July day of 2009, it remained the political hub, as evidenced by the sudden appearance of Florence’s new mayor, Matteo Renzi, who was rushing from his office to a waiting car.
The scientific lecture ceased as Dr. Seracini moved quickly to intercept the mayoral entourage. He was eager to use the second essential strategy for retrieving a Leonardo painting in Florence: find the right patron.
That has always been a good tactic in the home of the Medicis and bureaucrats like Machiavelli, a friend of Leonardo’s who signed the contract commissioning the battle mural. Dr. Seracini, an engineering professor at the University of California, San Diego, had spent years in bureaucratic limbo waiting to try his neutron-beam technique, but he saw this new mayor as his best hope yet for finding Leonardo’s work.
The quest had begun more than three decades earlier with a clue fit for a Dan Brown novel. In 1975, after studying engineering in the United States, Dr. Seracini returned to his native Florence and surveyed the Hall of 500 with a Leonardo scholar, Carlo Pedretti.
They were looking for “The Battle of Anghiari,” the largest painting Leonardo ever undertook (three times the width of “The Last Supper”). Although it was never completed — Leonardo abandoned it in 1506 — he left a central scene of clashing soldiers and horses that was hailed as an unprecedented study of anatomy and motion. For decades, artists like Raphael went to the Hall of 500 to see it and make their own copies.
Then it vanished. During the remodeling of the hall in 1563, the architect and painter Giorgio Vasari covered the walls with frescoes of military victories by the Medicis, who had returned to power. Leonardo’s painting was largely forgotten.
But in 1975, when Dr. Seracini studied one of Vasari’s battle scenes, he noticed a tiny flag with two words, “Cerca Trova”: essentially, seek and ye shall find. Was this Vasari’s signal that something was hidden underneath?
The technology of the 1970s did not provide much of an answer. Dr. Seracini went on to make his name with scientific analyses of other works of art, and to found the Center of Interdisciplinary Science for Art, Architecture and Archaeology at U.C.S.D. In 2000 he returned to the hall with new technology and a new financial patron, Loel Guinness, a British philanthropist. By taking infrared pictures and laser-mapping the room, Dr. Seracini’s team discovered where the doors and windows had been before Vasari’s remodeling.
The reconstructed blueprint, combined with 16th-century documents, was enough to locate the spot painted by Leonardo. It also offered a potential explanation for Michelangelo’s failure to do anything more than an initial sketch for his mural: He must have been miffed that Leonardo was assigned a section of the wall with much better window light.
“This room is huge, but it wasn’t big enough for both Michelangelo and Leonardo,” Dr. Seracini said. (Visit nytimes.com/tierneylab for more details.)
The new analysis showed that the spot painted by Leonardo was right at the “Cerca Trova” clue. The even better news, obtained from radar scanning, was that Vasari had not plastered his work directly on top of Leonardo’s. He had erected new brick walls to hold his murals, and had gone to special trouble to leave a small air gap behind one section of the bricks — the section in back of “Cerca Trova.”
But how could anyone today know what lay behind the fresco and the bricks? How could anyone peer six inches into the wall without harming the historic fresco on the surface?
Dr. Seracini was stymied until 2005, when he appealed for help at a scientific conference and got a suggestion to send beams of neutrons harmlessly through the fresco. With help from physicists in the United States, Italy’s nuclear-energy agency and universities in the Netherlands and Russia, Dr. Seracini developed devices for identifying the telltale chemicals used by Leonardo.
One device can detect the neutrons that bounce back after colliding with hydrogen atoms, which abound in the organic materials (like linseed oil and resin) employed by Leonardo. Instead of using water-based paint for a traditional fresco in wet plaster like Vasari’s, Leonardo covered the wall with a waterproof ground layer and used oil-based paints.
The other device can detect the distinctive gamma rays produced by collisions of neutrons with the atoms of different chemical elements. The goal is to locate the sulfur in Leonardo’s ground layer, the tin in the white prime layer and the chemicals in the color pigments, like the mercury in vermilion and the copper in blue pigments of azurite.
Developing this technology was difficult, but not as big a challenge as getting permission to use it. Dr. Seracini kept running into political and bureaucratic dead ends. So when he saw the new mayor dashing across the Hall of 500 that July afternoon, Dr. Seracini rushed at the chance for a personal to appeal to Mr. Renzi, who had been a fan of the project before his election.
With the politesse of a Medici, the mayor paused and listened, then promised to further this artistic endeavor once he had dealt with his first batch of election pledges.
“My dream is to see this discovery very soon,” Mr. Renzi said. “Soon” can be a highly relative term in Italian bureaucracies, but the mayor did indeed go on to restart the approval process and meet with one of the current patrons of the project, the National Geographic Society. Last week, the mayor said he expected it to proceed shortly.
“We are very willing to give Professor Seracini permission,” Mr. Renzi said Thursday. “The only issue that remains concerns timing — who does what. Within a week or two it should get the go-ahead.”
Once he gets permission, Dr. Seracini said, he hopes to complete the analysis within about a year. If “The Battle of Anghiari” is proved to be there, he said, it would be feasible for Florentine authorities to bring in experts to remove the exterior fresco by Vasari, extract the Leonardo painting and then replace the Vasari fresco. Of course, no one knows what kind of shape the painting might be in today. But Dr. Seracini, who has extensively analyzed the damages suffered by many Renaissance paintings, said that he was optimistic about “The Battle of Anghiari.”
“The advantage is that it has been covered up for five centuries,” he said. “It’s been protected against the environment and vandalism and bad restorations. I don’t expect there to be much decay.”
If he is right, then perhaps Vasari did Leonardo a favor by covering up the painting — and taking care to leave that cryptic little flag above the trove.
By C. CLAIBORNE RAY, The New York Times, October 6, 2009
Q. Why do identical twins have different fingerprints? Why do we have fingerprints to begin with?
A. The probable answers to both questions are related to the minute differences in the mechanical forces each developing fetus experiences in the uterus as its cells proliferate.
Researchers have found that identical twins have a very high correlation of loops, whorls and ridges, but a review study last year in Circulation Research examining how complex structures like the circulatory system develop says that “the detailed ‘minutiae’ — where skin ridges meet, end or bifurcate — are different even between identical twins.” Even twins that develop from one zygote occupy different positions in the womb, and the variations are enough to make a difference.
At the crucial stage of development, the study explains, ridges are thought to form as compressive stresses develop in the dermal cell layer of the skin, sandwiched between the epidermis and the subcutaneous tissue. “Like the buckling of land masses under compression,” the study continues, regular ridges form to relieve the stress.
Where the skin is flat, the ridges are parallel; but primates have raised pads on their fingertips at this stage, so the ridges form along lines of equal stress. “Surrounding the highest point of the raised pad,” the study says, “ridges form in concentric circles.” Meanwhile, the pads are regressing, but where they remain high longer, ridges form whorls. Pads that have largely regressed give rise to a simple arch pattern. Where the processes of ridge formation and pad regression overlap, an intermediate loop pattern results.
Mind: How Nonsense Sharpens the Intellect
By BENEDICT CAREY, The New York Times, October 6, 2009
In addition to assorted bad breaks and pleasant surprises, opportunities and insults, life serves up the occasional pink unicorn. The three-dollar bill; the nun with a beard; the sentence, to borrow from the Lewis Carroll poem, that gyres and gimbles in the wabe.
An experience, in short, that violates all logic and expectation. The philosopher Soren Kierkegaard wrote that such anomalies produced a profound “sensation of the absurd,” and he wasn’t the only one who took them seriously. Freud, in an essay called “The Uncanny,” traced the sensation to a fear of death, of castration or of “something that ought to have remained hidden but has come to light.”
At best, the feeling is disorienting. At worst, it’s creepy.
Now a study suggests that, paradoxically, this same sensation may prime the brain to sense patterns it would otherwise miss — in mathematical equations, in language, in the world at large.
“We’re so motivated to get rid of that feeling that we look for meaning and coherence elsewhere,” said Travis Proulx, a postdoctoral researcher at the University of California, Santa Barbara, and lead author of the paper appearing in the journal Psychological Science. “We channel the feeling into some other project, and it appears to improve some kinds of learning.”
Researchers have long known that people cling to their personal biases more tightly when feeling threatened. After thinking about their own inevitable death, they become more patriotic, more religious and less tolerant of outsiders, studies find. When insulted, they profess more loyalty to friends — and when told they’ve done poorly on a trivia test, they even identify more strongly with their school’s winning teams.
In a series of new papers, Dr. Proulx and Steven J. Heine, a professor of psychology at the University of British Columbia, argue that these findings are variations on the same process: maintaining meaning, or coherence. The brain evolved to predict, and it does so by identifying patterns.
When those patterns break down — as when a hiker stumbles across an easy chair sitting deep in the woods, as if dropped from the sky — the brain gropes for something, anything that makes sense. It may retreat to a familiar ritual, like checking equipment. But it may also turn its attention outward, the researchers argue, and notice, say, a pattern in animal tracks that was previously hidden. The urge to find a coherent pattern makes it more likely that the brain will find one.
“There’s more research to be done on the theory,” said Michael Inzlicht, an assistant professor of psychology at the University of Toronto, because it may be that nervousness, not a search for meaning, leads to heightened vigilance. But he added that the new theory was “plausible, and it certainly affirms my own meaning system; I think they’re onto something.”
In the most recent paper, published last month, Dr. Proulx and Dr. Heine described having 20 college students read an absurd short story based on “The Country Doctor,” by Franz Kafka. The doctor of the title has to make a house call on a boy with a terrible toothache. He makes the journey and finds that the boy has no teeth at all. The horses who have pulled his carriage begin to act up; the boy’s family becomes annoyed; then the doctor discovers the boy has teeth after all. And so on. The story is urgent, vivid and nonsensical — Kafkaesque.
After the story, the students studied a series of 45 strings of 6 to 9 letters, like “X, M, X, R, T, V.” They later took a test on the letter strings, choosing those they thought they had seen before from a list of 60 such strings. In fact the letters were related, in a very subtle way, with some more likely to appear before or after others.
The test is a standard measure of what researchers call implicit learning: knowledge gained without awareness. The students had no idea what patterns their brain was sensing or how well they were performing.
But perform they did. They chose about 30 percent more of the letter strings, and were almost twice as accurate in their choices, than a comparison group of 20 students who had read a different short story, a coherent one.
“The fact that the group who read the absurd story identified more letter strings suggests that they were more motivated to look for patterns than the others,” Dr. Heine said. “And the fact that they were more accurate means, we think, that they’re forming new patterns they wouldn’t be able to form otherwise.”
Brain-imaging studies of people evaluating anomalies, or working out unsettling dilemmas, show that activity in an area called the anterior cingulate cortex spikes significantly. The more activation is recorded, the greater the motivation or ability to seek and correct errors in the real world, a recent study suggests. “The idea that we may be able to increase that motivation,” said Dr. Inzlicht, a co-author, “is very much worth investigating.”
Researchers familiar with the new work say it would be premature to incorporate film shorts by David Lynch, say, or compositions by John Cage into school curriculums. For one thing, no one knows whether exposure to the absurd can help people with explicit learning, like memorizing French. For another, studies have found that people in the grip of the uncanny tend to see patterns where none exist — becoming more prone to conspiracy theories, for example. The urge for order satisfies itself, it seems, regardless of the quality of the evidence.
Still, the new research supports what many experimental artists, habitual travelers and other novel seekers have always insisted: at least some of the time, disorientation begets creative thinking.
Findings: A High-Tech Hunt for Lost Art
By JOHN TIERNEY, The New York Times, October 6, 2009
If you believe, as Maurizio Seracini does, that Leonardo da Vinci’s greatest painting is hidden inside a wall in Florence’s city hall, then there are two essential techniques for finding it. As usual, Leonardo anticipated both of them.
First, concentrate on scientific gadgetry. After spotting what seemed to be a clue to Leonardo’s painting left by another 16th-century artist, Dr. Seracini led an international team of scientists in mapping every millimeter of the wall and surrounding room with lasers, radar, ultraviolet light and infrared cameras. Once they identified the likely hiding place, they developed devices to detect the painting by firing neutrons into the wall.
“Leonardo would love to see how much science is being used to look for his most celebrated masterpiece,” Dr. Seracini said, gazing up at the wall where he hopes the painting can be found, and then retrieved intact. “I can imagine him being fascinated with all this high-tech gear we’re going to set up.”
Dr. Seracini was standing in the Palazzo Vecchio’s grand ceremonial chamber, the Hall of 500, which was the center of Renaissance politics when Leonardo and Michelangelo were commissioned to adorn it with murals of Florentine military victories. On this July day of 2009, it remained the political hub, as evidenced by the sudden appearance of Florence’s new mayor, Matteo Renzi, who was rushing from his office to a waiting car.
The scientific lecture ceased as Dr. Seracini moved quickly to intercept the mayoral entourage. He was eager to use the second essential strategy for retrieving a Leonardo painting in Florence: find the right patron.
That has always been a good tactic in the home of the Medicis and bureaucrats like Machiavelli, a friend of Leonardo’s who signed the contract commissioning the battle mural. Dr. Seracini, an engineering professor at the University of California, San Diego, had spent years in bureaucratic limbo waiting to try his neutron-beam technique, but he saw this new mayor as his best hope yet for finding Leonardo’s work.
The quest had begun more than three decades earlier with a clue fit for a Dan Brown novel. In 1975, after studying engineering in the United States, Dr. Seracini returned to his native Florence and surveyed the Hall of 500 with a Leonardo scholar, Carlo Pedretti.
They were looking for “The Battle of Anghiari,” the largest painting Leonardo ever undertook (three times the width of “The Last Supper”). Although it was never completed — Leonardo abandoned it in 1506 — he left a central scene of clashing soldiers and horses that was hailed as an unprecedented study of anatomy and motion. For decades, artists like Raphael went to the Hall of 500 to see it and make their own copies.
Then it vanished. During the remodeling of the hall in 1563, the architect and painter Giorgio Vasari covered the walls with frescoes of military victories by the Medicis, who had returned to power. Leonardo’s painting was largely forgotten.
But in 1975, when Dr. Seracini studied one of Vasari’s battle scenes, he noticed a tiny flag with two words, “Cerca Trova”: essentially, seek and ye shall find. Was this Vasari’s signal that something was hidden underneath?
The technology of the 1970s did not provide much of an answer. Dr. Seracini went on to make his name with scientific analyses of other works of art, and to found the Center of Interdisciplinary Science for Art, Architecture and Archaeology at U.C.S.D. In 2000 he returned to the hall with new technology and a new financial patron, Loel Guinness, a British philanthropist. By taking infrared pictures and laser-mapping the room, Dr. Seracini’s team discovered where the doors and windows had been before Vasari’s remodeling.
The reconstructed blueprint, combined with 16th-century documents, was enough to locate the spot painted by Leonardo. It also offered a potential explanation for Michelangelo’s failure to do anything more than an initial sketch for his mural: He must have been miffed that Leonardo was assigned a section of the wall with much better window light.
“This room is huge, but it wasn’t big enough for both Michelangelo and Leonardo,” Dr. Seracini said. (Visit nytimes.com/tierneylab for more details.)
The new analysis showed that the spot painted by Leonardo was right at the “Cerca Trova” clue. The even better news, obtained from radar scanning, was that Vasari had not plastered his work directly on top of Leonardo’s. He had erected new brick walls to hold his murals, and had gone to special trouble to leave a small air gap behind one section of the bricks — the section in back of “Cerca Trova.”
But how could anyone today know what lay behind the fresco and the bricks? How could anyone peer six inches into the wall without harming the historic fresco on the surface?
Dr. Seracini was stymied until 2005, when he appealed for help at a scientific conference and got a suggestion to send beams of neutrons harmlessly through the fresco. With help from physicists in the United States, Italy’s nuclear-energy agency and universities in the Netherlands and Russia, Dr. Seracini developed devices for identifying the telltale chemicals used by Leonardo.
One device can detect the neutrons that bounce back after colliding with hydrogen atoms, which abound in the organic materials (like linseed oil and resin) employed by Leonardo. Instead of using water-based paint for a traditional fresco in wet plaster like Vasari’s, Leonardo covered the wall with a waterproof ground layer and used oil-based paints.
The other device can detect the distinctive gamma rays produced by collisions of neutrons with the atoms of different chemical elements. The goal is to locate the sulfur in Leonardo’s ground layer, the tin in the white prime layer and the chemicals in the color pigments, like the mercury in vermilion and the copper in blue pigments of azurite.
Developing this technology was difficult, but not as big a challenge as getting permission to use it. Dr. Seracini kept running into political and bureaucratic dead ends. So when he saw the new mayor dashing across the Hall of 500 that July afternoon, Dr. Seracini rushed at the chance for a personal to appeal to Mr. Renzi, who had been a fan of the project before his election.
With the politesse of a Medici, the mayor paused and listened, then promised to further this artistic endeavor once he had dealt with his first batch of election pledges.
“My dream is to see this discovery very soon,” Mr. Renzi said. “Soon” can be a highly relative term in Italian bureaucracies, but the mayor did indeed go on to restart the approval process and meet with one of the current patrons of the project, the National Geographic Society. Last week, the mayor said he expected it to proceed shortly.
“We are very willing to give Professor Seracini permission,” Mr. Renzi said Thursday. “The only issue that remains concerns timing — who does what. Within a week or two it should get the go-ahead.”
Once he gets permission, Dr. Seracini said, he hopes to complete the analysis within about a year. If “The Battle of Anghiari” is proved to be there, he said, it would be feasible for Florentine authorities to bring in experts to remove the exterior fresco by Vasari, extract the Leonardo painting and then replace the Vasari fresco. Of course, no one knows what kind of shape the painting might be in today. But Dr. Seracini, who has extensively analyzed the damages suffered by many Renaissance paintings, said that he was optimistic about “The Battle of Anghiari.”
“The advantage is that it has been covered up for five centuries,” he said. “It’s been protected against the environment and vandalism and bad restorations. I don’t expect there to be much decay.”
If he is right, then perhaps Vasari did Leonardo a favor by covering up the painting — and taking care to leave that cryptic little flag above the trove.