Chapter 31: I Hope He's a Genius

Lin Ran smiled as he took his hand and replied, "Thank you, Sir Lincoln. I have long heard of the academic vitality here at the University of Hong Kong, and I hope my arrival can inject new vigor into this place."

Lin Ran’s English had long been refined to the most standard American accent.

Zhang Tianze, the head of the Department of Mathematics, stepped forward impatiently. Speaking in Mandarin tinged with a Cantonese accent, he said, "Professor Lin, it is an honor. Our department organized a month-long seminar to discuss your paper on the proof of Fermat’s Last Theorem. There are still some points of doubt that we hope you can personally clarify. Your description of the 'birds and the frogs' has also resonated deeply with us, and we look forward to hearing your insights on learning mathematics and conducting mathematical research. Furthermore, our students are very much looking forward to your seminar."

His tone carried a hint of reverence. Mathematics is a discipline where the boundary between the strong and the weak is exceptionally clear. Another crucial aspect is that mathematics is a field that relies heavily on lineage. While many hold the stereotype that mathematical research relies solely on pen, paper, and books, it is, in reality, deeply dependent on academic heritage.

The University of Minnesota once launched the "Mathematics Genealogy Project," a web database initiated by Harry B. Coonce in the autumn of 1997 to track the academic lineages of mathematicians. It sought to gather information on all mathematicians globally, including those with doctoral degrees. For the vast majority of famous mathematicians, one can trace a clear ancestral lineage of mentorship. The University of Göttingen became a mathematical hub because of Gauss; Soviet mathematics became formidable thanks to the great Euler; Paris became a center because of luminaries like Grothendieck. Later, Princeton rose to prominence because German scientists fled from Göttingen to Princeton after World War II.

To Zhang Tianze, Lin Ran—a man who possessed the Langlands Program—was the kind of mathematician who could elevate the University of Hong Kong to new heights.

Lin Ran turned to him, smiling slightly, and replied in standard Mandarin, "Professor Zhang is too kind. I have come here to explore mathematics with the students in Hong Kong, and I hope they, too, will find inspiration."

He then added a phrase in Cantonese: "Thank you for your warm welcome."

Though his Cantonese was not entirely fluent, it drew a wave of friendly laughter and applause from the locals present.

A member of the Board of Governors, a wealthy businessman named Mr. Wong, stepped forward and interjected: "Professor Lin, you are the pride of the Chinese people. Being able to prove a conjecture that has remained unsolved for centuries—your return to Hong Kong is truly a testament to our glory!" His voice was booming, and his face was wreathed in smiles.

Lin Ran’s visit had electrified the people of Hong Kong. On one hand, he was a world-renowned mathematician; on the other, rumor had it that Cambridge and Oxford had both requested him as a visiting professor, and while he had turned them down, he had accepted the University of Hong Kong. Even though they shared a common heritage, it was a massive morale boost for the people of Hong Kong. The wealthy Chinese businessmen present, through their connections with the Hong Kong government, knew that the rumors of him rejecting Cambridge and Oxford were, in fact, true.

Lin Ran nodded slightly and responded modestly, "Mr. Wong, you are too generous. I am merely a student of mathematics, and bringing honor to my people is an unexpected joy. During my time in Hong Kong, I hope most of all to help the younger generation of our people grow together."

His tone was calm but carried an air of firmness that made Mr. Wong nod repeatedly.

At this moment, the surrounding reporters could no longer contain themselves. A reporter from the *South China Morning Post* pushed his way to the front, his pen nearly poking Lin Ran in the face. "Professor Lin, what are your plans for the seminar? What knowledge will you be imparting to our students?" His tone was urgent, and his English was an exceptionally standard London accent.

Lin Ran chuckled and replied, "I believe the most important thing is to teach them methods of thinking and interesting mathematical problems, with the hope of sparking their curiosity."

Lin Ran’s answer was watertight. He certainly could not say, "I am here to teach variational calculus and optimal control theory related to the trajectory optimization of intercontinental ballistic missiles."

It was true that Qian Xuesen was a pioneer in cybernetics, and his work on engineering cybernetics remains applicable to this day. However, optimal control theory only truly emerged in November 1960 at the first International Federation of Automatic Control congress in Moscow, following the introduction of dynamic programming by Bellman, the maximum principle by Pontryagin, and LQ theory by Kalman.

The theories Lin Ran intended to teach were not merely crude variational calculus, but algorithms that would later be extensively validated in the space race. Furthermore, considering the lack of computers in China and the reliance on manual calculation, he had specifically optimized these algorithms. Take Pontryagin’s maximum principle, proposed in 1956, as an example; it was used in the design of America’s Redstone rockets and the Soviet Union’s R-7 rockets. But why couldn't China use it? Because China lacked the IBM computers to provide the computing power. Relying on hand-calculation alone made the maximum principle far too difficult.

Lin Ran needed to teach these theories in public without making it obvious that they were related to aerospace. How could he use the language of future mathematics to disguise missile trajectories as purely academic games?

Lin Ran did not yet know who the Chinese authorities had sent, but he had already casually mentioned to Huang Yunji, the publisher of the *Chinese American Daily*, that he enjoyed dealing with true geniuses.

"I hope whoever they sent is a real genius," Lin Ran mused to himself amidst the bustling crowd. "Otherwise, if I redefine the target function of an optimal flight path as a functional extremum problem and claim I am studying the properties of extrema in abstract spaces—if I pack air resistance and thrust into perturbation operators, and disguise multi-body gravity as the action of a symmetry group—they’ll be completely lost if they don’t understand."

As the conversation unfolded, the crowd of students grew. Several young people in white school uniforms held up homemade signs reading, "Welcome, Dr. Lin!" Others used chalk to draw a large "∞" on the ground, symbolizing the infinite charm of mathematics.

Many heads poked out from the windows of the teaching building. Female students peered through binoculars, whispering to one another:

"Did you see? Did you see him?"
"Is he handsome?"
"Laura, give me the binoculars!"
"He really is quite handsome, and young too. I wonder who will seize the opportunity in these two months."
"I heard that Professor Lin can leave Einstein dizzy just by speaking!"
"He’s a mathematician, not a physicist!"
"Do you think you can get into his class? I didn't even dare pick up the application form!"

Laughter and conversation intertwined, and the air was thick with reverence for the great mathematician.