What was Lisa Gherardini smiling about when she posed for the Mona Lisa, the world’s most famous painting? Had the painter, Leonardo da Vinci (1452-1519), just made a joke? Was Gherardini remembering a delicious meal? New research suggests that she was smiling because she just had or was going to have a baby!
Scientists and museum curators1 reached that conclusion after examining the painting with state-of-the-art2 instruments. The Mona Lisa hangs in a very secure display case in the Louvre museum in Paris. In October 2004, when the painting was transferred to this new case, scientists got a once-in-a-lifetime chance to examine it.
Laser Vision
The scientists included representatives from the National Research Council of Canada. The Canadians brought with them one of the world’s most sophisticated three dimensional scanners3.
The Canadian team was looking for damage to the painting from climate and age.“Our first question was, how well conserved is it?” says Louis Borgeat, one of the scientists.
The 3-D scanner shines a laser at a painting. Changes in the thickness of the surface reflect the laser at different angles. A computer then uses triangulation4, a mathematical method that calculates distances from angles, to map5 the shape of the painting’s surface.
The same laser also examines color. The laser is a combination of red, blue, and green light, the three additive primary colors6 that mix to create white light. The scanner records how much of each color is in a painting.
The laser scanner produced a copy of the painting onto a computer screen. With this image researchers can subtract7 the color to better see the painting’s surface texture. Or they can add false light8 to cast virtual9 shadows that reveal hidden details.
Finding Relief10
The scans reveal that the Mona Lisa is in good health. Da Vinci painted the portrait 500 years ago on a wooden panel that is vulnerable11 to warping12 with changes in temperature and humidity13. The scans show that the paint is still bonded14 to the wood and won’t deteriorate15 in a climate-controlled case. One large crack16 in the wood won’t grow larger either. “The painting is in very good condition,” says Borgeat.
The scans also reveal that the Mona Lisa is surprisingly flat. “We’ve scanned other paintings, like Renoir’s, and when you zoom in17, the paint looks like mountain ranges,” says Borgeat. When the researchers removed the color from the virtual Mona Lisa and zoomed in on its surface, instead of mountains, they saw what looked like the surface of a frozen pond, “It is almost like there is no visible paint in the painting,” Borgeat says.
Da Vinci created the Mona Lisa without leaving lots of paint on the wood. He used a technique called sfumato18, in which he added very thin layers of paint. No one knows exactly how he did that.
Infrared Threads
While the Mona Lisa was out of its protective case, a team from the French Museum’s Center for Research and Restoration also scanned it, but with infrared (IR) light. Infrared light is a form of electromagnetic radiation that is invisible to human eyes. Art researchers have discovered that they can see through some layers of paint by shining IR light on a work of art and using a camera to detect the reflected light.
Scanning the Mona Lisa with IR light, the researchers found that hidden details appeared. Age has darkened the Mona Lisa, and the researchers discovered that the outer layer of Lisa Gherardini’s clothing, which appears to be dark and thick, is really a thin, painted veil. When viewed under IR light, the shape and texture of the veil became obvious. The veil was the type women wore during the Renaissance when they were pregnant or had just given birth.
Safe Keeping
The 3-D digital image of the Mona Lisa is thousands of times more detailed than today’s computer-generated, animated movies, says Borgeat. Having a virtual Mona Lisa, he adds, will allow research on the painting to continue while the real Mona Lisa is kept safe from moisture, heat, and cold.
“The curators are very careful,” says Borgeat. “Mona Lisa is their most precious piece of art.”
(Special permission granted by WRC Media, Inc. All rights reserved by WRC Media, Inc. www.wrcmedia.com)
当丽莎·盖拉尔迪尼为世界上最著名的油画《蒙娜丽莎》充当模特时，她缘何而笑呢？难道这只是画家达·芬奇（1452-1519）跟世人开的一个玩笑？或是当时盖拉尔迪尼正在回味一顿美味大餐？最新研究表示，她微笑的原因是她刚刚分娩或是有孕在身。
科学家们和博物馆馆员们是在利用尖端科技手段对这幅画进行深入研究后才得出这一结论的。名画《蒙娜丽莎》被陈列在法国巴黎卢浮宫一个安全可靠的展箱中。2004年，当这幅画转移到这个展箱时，科学家们才得到千载难逢的机会来对它进行研究。
激光视觉
参与研究的科学家包括来自加拿大国家科学研究委员会的代表，他们带来了一台世界上最为精密的三维扫描仪。
加拿大科学家小组探查了气候和时间对这幅油画的损毁状况。其中一位科学家路易斯·伯格特说：“我们的第一个疑问是，它的保存状况如何？”
三维扫描仪将一束激光投射到油画上，表层厚度的差异使激光从不同角度反射，然后电脑运用一种按照角度来计算距离的数学方法——三角测量法来绘制油画的表面形态。
同一束激光也能对油画色彩进行考察。激光包含红、绿、蓝三种颜色，这也正是产生白色光的加法三原色。扫描仪对各种颜色在画作中的比例进行了记录。
激光扫描仪制作了一份油画副本并显示到电脑屏幕上。通过这幅映象，研究者们可以移除画作的色彩，更好地看清它表面的纹理。或者，他们在激光束中添加杂光，投射出虚拟的阴影，以揭露画中所隐藏细节。
结果令人放心
扫描显示《蒙娜丽莎》的“健康”状况良好。达·芬奇500年前将蒙娜丽莎绘制在一张容易受温度和气候变化影响而变形的画板上，但画层仍然非常坚固地附着在画板上，并且在温度、湿度控制良好的展箱中，不会被毁坏。此外画板上的一道大裂缝也没有扩大的趋势。“这幅油画保存状况非常好。”伯格特如是说。
扫描还显示油画《蒙娜丽莎》画面格外平整。伯格特说：“我们也扫描了其他的一些画作，例如法国印象派画家雷诺阿的作品，当我们放大画面的时候，可以发现画作表面如山脉般起伏不平。”而当研究者们从虚拟的《蒙娜丽莎》画像中剔出色彩的时候，他们看到的不是凸凹的山脉，而更像是冰封的池面，“仿佛画作上没有明显可见的涂料。”伯格特这样说道。
达·芬奇在创作《蒙娜丽莎》时，并没在画板上涂上过多的油彩。他采用了“渲染层次”手法，只是着了一层薄薄的色。然而对其确切的操作技法却是无人知晓。
红外线
当《蒙娜丽莎》从其防护箱中取出时，来自法国博物馆研究和修复中心的研究小组也对其进行了扫描，不过是利用红外线。红外线是一种肉眼看不见的电磁辐射线。艺术研究家们发现，将红外线投射到艺术品上，再运用照相机来捕获反射光，他们可以看透好几层颜料。
研究者发现，对《蒙娜丽莎》进行红外线扫描，一些隐藏的细节开始出现。绘画的颜色已经随着时间变暗了。此外，丽莎·盖拉尔迪尼的衣服外面其实是一件着了色的薄纱，尽管它看起来灰暗而厚重。在红外线下观察，这层纱的轮廓和质地就变得明晰了，它其实是文艺复兴时期妇女怀孕时或刚分娩后的衣着。
绘画安全无恙
《蒙娜丽莎》的3D数字图像表现出来的细节比当今电脑生成的动画影片要丰富好几千倍，伯格特说。他还说，制作一个虚拟的蒙娜丽莎画像，可以使研究者继续研究这幅绘画，而真画则收藏在不受湿气和温度影响的陈列箱里。
“博物馆馆员非常小心，”伯格特说。“《蒙娜丽莎》是他们最珍贵的艺术品。”
1. curator n. 博物馆员
2. state-of-the-art 最先进的
3. dimensional scanner 三维扫描仪
4. triangulation n. 三角测量
5. map v. 绘制
6. additive primary colors 加法三原色，红、绿、蓝三种基本色以不同的比例混合可形成不同的色，如果将这三种基色等量混合便会形成白色光。
7. subtract ] v. 减去
8. false light 杂光
9. virtual adj. 虚拟的
10. relief n. 减缓，负担或忧虑的缓解
11. vulnerable adj. (to) 易受攻击的, 易受…的攻击
12. warping n. 弯曲、变形
13. humidity n. 潮湿
14. bond v. 粘合
15. deteriorate v. 恶化
16. crack n. 裂缝
17. zoom in （镜头）推近，移向目标
18. sfumato n. (使素描中的明暗或色彩中的色阶有层次地调和)渲染层次