Physics vs Mona Lisa
The wood and smile of the Mona Lisa fascinate scientists. Not wooden smile. Wood and smile. A in the Journal of Cultural Heritage reveals how researchers have spent 18 years exploring the wooden panel on which Leonardo da Vinci painted the Mona Lisa. Their quest: to find a 鈥渕ethod to assess the hygro-mechanical behaviour of original panel paintings, through in situ non-invasive continuous monitoring鈥�.
Other scientists, bunches of them, have peered and peered at the little puzzle that rests atop that wood. Having seen everything else fail, some of them have been throwing their heaviest of tools 鈥� physics 鈥� at the art world鈥檚 toughest problem. The issue, which dates from about the year 1507, is this: how do you explain the Mona Lisa鈥榮 smile? Some studies subject the woman to quantum mechanics and fluid dynamics.
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She has had to deal with far more personal probes in the past. Doctors and biologists have churned out reports suggesting that , that , that or that she had other ailments, some nearly unmentionable.
Slobodan Prvanovic at the Institute of Physics in Belgrade, Serbia, applied more conceptual methods, stepping up with a study called . Prvanovic explains that 鈥渢he mysterious state Mona Lisa is in鈥� is a coherent superposition of two quantum states: cheerfulness and sadness. The application of these concepts to this question is so new that many physics textbooks don鈥檛 mention it.
By Feedback鈥檚 estimation, the most moving study is by Diogo Queiros-Conde, a physicist at Mines ParisTech, France.
Sfumato, Queiros-Conde explains, is 鈥渁 painting technique using thin layers of color that are superimposed and intermixed in order to create effects of perspective, depth and volume鈥�. Queiros-Conde disassembles the Mona Lisa鈥榮 sfumato using some of the tools of fluid dynamics. He begins with Andrey Kolmogorov鈥檚 technique for analysing the local structure of turbulence in incompressible viscous fluid for very large Reynolds numbers. This by itself isn鈥檛 powerful enough to finish the job, so Queiros-Conde caps it with a new geometrical approach of his own devising. Called entropic skins geometry, this pertains to the statistics and geometry of fully developed turbulent flows. The details are nothing if not engrossing.
The highlight is Queiros-Conde鈥檚 discovery of something that 500 years of art scholars seem to have missed. On the final page of his study, he writes: 鈥淚 advise the reader to pay attention to the luminous form just under Mona Lisa鈥檚 left shoulder.鈥� The reward is ample. There, he writes, 鈥渙ne should recognize a form that can be interpreted as a human skull鈥�.
Maths vs Mona Lisa
Some scientists feel that maths, not physics, is the heaviest of assault weapons. They deploy it when handed some problem that has defied solution and maybe made people cry. The Mona Lisa brings many such problems.
Alessia Amelio at the University of Calabria, Italy, went on a mental adventure ride, collecting some of the mathematical methods that people have taken to war against the Mona Lisa鈥榮 mystery. She describes part of that armoury in a paper called , delivered in Pisa in 2019. Here are some of the methods: computed Mahalanobis distance; inverse Fourier transform; bi-scatter plot pixel counting; genetic algorithms; and ant colony optimisation, to name just a few.
The study tells at length and depth about attempts to calculate estimates of the age of the woman in the artwork, whose painted form has apparently (but maybe not actually, as you will, uh, see in a moment) been staring strangers in the eye for more than half a millennium now.
Still, the problem remains unsolved. The Mona Lisa continues to braintease. The situation can be embarrassing to almost anyone, if they have read a study by Gernot Horstmann and Sebastian Loth at Bielefeld University, Germany, called . Reader Dany Adams, herself a biologist, brought it to Feedback鈥檚 attention.
The study tries to explain what is known as 鈥渢he Mona Lisa effect鈥�. You perceive the painted eyes as gazing directly at you, no matter where you stand. Move left or right, Lisa is still looking at you.
Horstmann and Loth had volunteers gaze at zoomed-in portions of the image, rather than at the full original. Viewers would, for example, see the painting with some of its left side removed, so that Lisa鈥檚 face was at the left of the frame, rather than the centre. The researchers performed careful measurements. They pondered their data. They concluded that the Mona Lisa effect happens when people see the complete painting, but not so much when they see only a portion.
鈥淲e demonstrated,鈥� they boast, 鈥渢hat Mona Lisa gazes to her left-hand side from about 35.5 cm inside pictorial space and 15.4掳 to the viewer鈥檚 right-hand side in real space鈥� There is no doubt about the existence of the Mona Lisa effect 鈥� it just does not occur with Mona Lisa herself.鈥�
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