Frank E. Marble
(Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena,
California 91125, U.S.A.)
In looking back I find it fascinating that the powerful impression made upon me by Kuo Yung-hua—that unique scholar and gentleman—resulted from rather few years of close scientific and social interaction. Although I was thoroughly acquainted with his important work on transonic flow, carried out in collaboration with Tsien Hsue-shen, it was not until Kuo came as a Visiting Professor to Caltech in 1954—1955 that we had the opportunity to share our mutual interests in fluid mechanics, applied mathematics and music.
For a period preceding his visit he had completed regularization of the Blasius problem by introducing an additional coordinate transformation, a work that he published in 1953. In his modest fashion Kuo did not make a point of the ground-breaking nature of his work, but he was, upon his arrival in Pasadena, actively pursuing analysis of the hypersonic boundary layer and wedge flow employing corresponding coordinate transformations. Because of the importance of the missile reentry problem at that time the work attracted a great deal of attention.
It is not clear whether Kuo recognized the relationship of this analysis to the work of Poincare and of Lighthill; if he did, he was again too modest to bring it to the attention of others. Tsien, however, clearly saw the similar aspects and developed a unified theory which he called the P(oincare) L(ighthill) K(uo) method and published in 1955.
After the Kuo family returned to Ithaca in the spring of 1955, Professor William R. Sears kindly offeredme a Visiting Professorship at Cornell in the spring of 1956 which, among many other advantages, gave the Marbles the opportunity of continuing interaction with the Kuos. In the course of that term it became clear that Kuo would be returning to China, perhaps later that year. Thus it transpired that as the Kuo family came to the west coast preparing to sail for China in September of 1956, we had the pleasure of their staying with us for several most enjoyable days.
We were never to see Kuo again, a tragedy we could not imagine as we saw them to their boat. But the image has remained clear of this brilliant productive intellect shielded by his kind gentlemanly manner. And this is my recollection of our dear friend on his 90th anniversary.
