Rajeev Motwani

Rajeev Motwani, 47, the Stanford University computer science professor who mentored Google's co-founders when they were graduate students, has died from a freak accident at his Atherton home.

Motwani apparently drowned Friday morning in a backyard swimming pool at the home he purchased three years ago. Friends said he did not know how to swim, but was planning to take lessons. While little official information was available, friends speculated that Motwani may have slipped and fallen in the pool. Paramedics were called when his body was found, and he was pronounced dead at the scene at 12:28 p.m., according to the San Mateo County coroners office.

He is survived by his wife, Asha Jadeja, and daughters Naitri and Anya. The family will hold a private funeral, according to the university's news agency, but a memorial service will be held at a later date.

The news of Motwani's death struck like a thunderclap in Silicon Valley. Blogs, Facebook pages and Twitter communications were filled with testimonials to a brilliant, kind man who was never too busy to help a budding entrepreneur or struggling graduate student. He helped many valley startups gain a foothold, but none so famous as Google, whose cofounder Sergey Brin mourned him Saturday.

Reached on the phone, Brin said the many conversations he had with Motwani helped inspire his thinking and research.

"I want him to really be remembered well. It's a rare combination to have somebody who is so smart and also such a nice guy." Motwani, he added, "had a lot of interest in computer science theory. He's primarily a theoretician, and it's incredible the amount of impact he has had directly on products and companies."

Brin also wrote in his blog on Friday: too.blogspot.com/2009/06/remembering-rajeev.html.

Silicon Valley's "ecosystem" has suffered a major blow with Motwani's death, said a friend, angel investor Ron Conway.

"He's a great example on how the Silicon Valley ecosystem works," said Conway, "which is why everyone is so upset at this tragedy. We've lost one of the best contributors to the Silicon Valley ecosystem."

"Everybody in Silicon Valley talked to him," said David Hornik, a valley venture capitalist. "Rajeev was an incredible resource to everyone."

Popular at Stanford

Born March 26, 1962, in Jammu, India, Motwani grew up in New Delhi, earned a computer science degree from the Indian Institute of Technology, Kanpur in 1983, and his doctorate from the University of California-Berkeley in 1988. As a Stanford professor, he also served as the director of graduate studies for the computer science department and founded the Mining Data at Stanford project (MIDAS).

His work had a major impact on the field of algorithms, and he used his knowledge of that field to develop methods for searching almost infinite archives of data by randomly selecting subsets of the data. It was in the field of data mining that he made some of his seminal contributions. The field is the basis of much of modern Internet commerce and the operation of search engines such as Google.

Motwani won perhaps the highest honor for theoretical computer science, the Göedel Prize, as well as earning an Alfred P. Sloan Foundation Research Fellowship. His contributions ranged over the computer science fields of search and information retrieval, streaming databases, data mining, robotics and even drug design.

Though he was not Brin's official adviser at Stanford, the Google cofounder wrote in his blog Friday that "he played just as big a role in my research, education, and professional development. In addition to being a brilliant computer scientist, Rajeev was a very kind and amicable person and his door was always open."

In 1998, Google cofounders Brin and Larry Page, Motwani and Stanford computer science professor Terry Winograd wrote a paper titled "What You Can Do With A Web In Your Pocket," describing the development of a global ranking of Web pages called PageRank and "a novel search engine called Google."

Brin wrote that when he became interested in data mining, a technology at the heart of Google's enormous success, Motwani helped coordinate a regular meeting group on the subject. After Google's founding, Motwani "remained a friend and adviser as he has with many people and startups since," Brin wrote. "Of all the faculty at Stanford, it is with Rajeev that I have stayed the closest and I will miss him dearly."

A rare gift

So will hundreds — perhaps thousands — of others whom he counseled or assisted with technical advice and encouragement, observed a colleague, Balaji Prabhakar, a Stanford computer science professor.

"People, when they speak to him, soon their vague and fuzzy ideas get transformed into crisp articulations," recalled Prabhakar. "There's nobody who has spoken to Rajeev who hasn't benefited from the experience," he said. "It's a rare gift."

"He enabled things," Prabhakar said. "He brought out the best in people, not by yanking at them, but things just came out. It was a little bit more magical an experience. People somehow found out something they didn't know they knew because they spoke to him — an idea they had that they didn't see, or an ability they possessed that he drew out."

Contact Pete Carey at pcarey@mercurynews.com or 408-920-5419.