今天是史上最伟大的业余数学家——费马(Pierre de Fermat)的410周年诞辰。为纪念这位业余数学家之王，Google今天的图标是费马大定理(话说为什么没有用坐标几何和概率论呢？)。今天同时也是我国计算数学的奠基人和开拓者冯康先生的忌日。冯康先生是为扶植青年才俊劳累过度而突然去世的。作为在计算数学领域做出多项开创性贡献的杰出数学家(参见2007-05-30转载的文章 “冯康的科学生涯——我的回忆ZZ” http://www.math.pku.edu.cn:8000/blog/post/140/1364)，冯先生具有崇高的国际声望。下面这篇纪念文章就是他去世后Lax大神所作的悼文，原载于SIAM NEWS 1993年第26卷第11期。

作者Peter Lax， 现为Courant所退休教授，美国科学院院士，原美国总统科学顾问，原美国数学会主席，原Courant所所长，曾获得美国国家科学奖章(1986)、 Wolf数学奖(1987)、美国数学会Steele终身成就奖(1992)、Abel奖(2005)等重要奖项。


Feng Kang, China's leading applied mathematician, died suddenly on August 17, in his 73rd year, after a long and distinguished career that had shown on sign of slowing.

Feng's early education was in electrical engineering, physics, and mathematics, a background that subtly shaped his later interests. He spent the early 1950s at the Steklov Institute in Moscow. Under the influence of Pontryagin, he began by working on problems of topological groups and Lie groups. On his return to China, he was among the first to popularize the theory of distributions.

In the late 1950s, Feng turned his attention to applied mathematics, where his most important contributions lie. Independently of parallel developments in the West, he created a theory of the finite element method. He was instrumental in both the implementation of the method and the creation of its theoretical foundation using estimates in Sobolev spaces. He showed how to combine boundary and domain finite elements effectively, taking advantage of integral relations satisfied by solutions of partial differential equations. In particular, he showed how radiation conditions can be satisfied in this way. He oversaw the application of the method to problems in elasticity as they occur in structural problems of engineering.

In the late 1980s, Feng proposed and developed so-called symplectic algorithms for solving evolution equations in Hamiltonian form. Combining theoretical analysis and computer experimentation, he showed that such methods, over long times, are much superior to standard methods. At the time of his death, he was at work on extensions of this idea to other structures.

Feng's significance for the scientific development of China cannot be exaggerated. He not only put China on the map of applied and computational mathematics, through his own research and that of his students, but he also saw to it that the needed resources were made available. After the collapse of the Cultural Revolution, he was ready to able to help the country build again from the ashes of this selfinflicted conflagration. Visitors to China were deeply impressed by his familiarity with new developments everywhere.

Throughout his life, Feng was fiercely independent, utterly courageous, and unwilling to knuckle under authority. That such a person did survive and thrive shows that even in the darkest days, the authorities were aware of how valuable and irreplaceable he was.

In Feng's maturity the well-deserved honors were bestowed upon him—membership in the Academia Sinica, the directorship of the Computing Center, the editorship of important journals, and other honors galore.

By that time his reputation had become international. Many remember his small figure at international conferences, his eyes and mobile face radiating energy and intelligence. He will be greatly missed by the mathematical sciences and by his numerous friends.