Had I been with Neil deGrasse Tyson, the director of the Hayden Planetarium, it wouldn't have been surprising had the discussion turned to extraterrestrials and how the intelligence of an advanced life form might differ from our own. But I wasn't talking to Mr. Tyson. The subject came up while I was interviewing Judea Pearl, the father of murdered Wall Street Journal reporter Daniel Pearl. He'd come to New York on Monday from his Los Angeles home to deliver the Simon Wiesenthal Center Museum of Tolerance's 2012 State of Anti-Semitism Lecture at Hunter College that night. Feb. 1 marked the 10th anniversary of his son's death.
Dr. Pearl, who is in his mid-70s, had managed to catch a few hours of sleep at the Waldorf-Astoria after flying in on a red-eye. He's a computer scientist at UCLA and an expert on artificial intelligence. Hence our discussion, which somehow led to extraterrestrial life.
His field of study is sufficiently arcane, at least to me, that even after reading his Wikipedia entry—it said he is "best known for championing the probabilistic approach to artificial intelligence and the development of Bayesian networks"—I still had no idea what was being talked about.
"I focus on handling uncertainty," he explained. "How do you encode a computer to look at noisy data, failures, things which happen which are not expected, predicted?"
He went on: "You have to encode experience, belief, hopes, expectations."
Thomas Bayes, of the networks mentioned above, was an 18th-century British mathematician who applied probability to all sorts of problems. The simple example Dr. Pearl gave was that if I think you have the flu, take your temperature and discover you have a fever, that data point increases my belief that you're sick. Bayes apparently came up with a formula that allows one to predict the degree to which evidence modifies one's belief in a hypothesis. "I just took his formula and generalized from one hypothesis to 10 million hypotheses," Dr. Pearl explained.
It was the subject of his 1988 book "Probabilistic Reasoning in Intelligent Systems," copy edited by Danny Pearl when he was a few years out of Stanford and while working as a reporter for the Berkshire Eagle in Western Massachusetts. "My publisher was looking for a copy editor," remembered Dr. Pearl, who recommended his son. The publisher was skeptical until the cub reporter submitted a couple of sample pages. "'He's hired,'" the publisher said.
I was impressed that Daniel Pearl, a journalist, was sufficiently versed in science and mathematics to edit a manuscript I suspect was significantly more challenging than your average Town Planning Board story. "He was considering a degree in computer science, music [he played the violin with the Berkshire Symphony Orchestra] and communications," Dr. Pearl said. His son chose communications, eventually leading to a job at The Wall Street Journal. He was serving as South Asia bureau chief when he traveled to Pakistan, to investigate connections between "shoe bomber" Richard Reid and al Qaeda. That's where he was kidnapped and beheaded.
Judea Pearl said that while growing up in Israel—he was born there in 1936—he had little personal exposure to anti-Semitism. "For me, anti-Semitism was a thing of the past," he remembered, "a totally eradicated disease like smallpox."
A war was raging across Europe and taking the lives of millions of Jews, but Dr. Pearl said, "My parents tried to hide from me what happened in Europe even though my mother's family perished there.
"I go into the kitchen," he went on, referring to when he became aware of the phenomenon, "and saw my mother crying. For five years she worried about the whereabouts of her sister."
His son's upbringing in the states—Daniel, who has two sisters, was born in Princeton, where his dad worked for RCA Research Laboratories, and grew up in Los Angeles—also led a charmed existence in that regard. As we sat in his 35th-floor room overlooking the Manhattan skyline, Judea Pearl had to wrack his brain for any exposure his son had to anti-Semitism. He came up with one incident: There was the time in junior high that Daniel came home from school with a bemused smile on his face.
"I said, 'What's so funny?'" his father remembered. "He said, 'This stupid teacher came up to me, looked at my Star of David and said, 'Look what I'm wearing.'" He pulled out a chain from which a swastika was dangling. "We didn't know what to do. Should we take it seriously or take it as a joke?"
The Anti-Defamation League was called, one of their representatives met with the school's principal and the teacher was reprimanded. "Danny took it as a stupid incident rather than a problem," Dr. Pearl said.
His thinking on the subject has obviously evolved since then, especially in the wake of his son's killing. "We have a new form of anti-Semitism which is called anti-Zionism," he said, previewing that evening's lecture. "One is a cover for the other. My point is it's as severe, as appalling, as racist. Unless you expose its character you're not fighting the right virus."
In his talk at Hunter, he characterized anti-Zionism as more insidious than anti-Semitism because "it hides itself in the cloak of political debate," according to coverage of the speech by the Jewish Daily Forward.
Our conversation returned to lighter fare, for example computers and his bold assertion that "the only way to study human nature is through computers. If you can program a phenomenon you can understand it."
However, he added that "the language of science is not fine enough to capture the mechanism of the mind."
I think that's where we, or at least I, broached the idea of extraterrestrial life and the question of what such a language—not just of science, but also of art and poetry—would look like in a civilization far more advanced than ours. A scientist, Dr. Pearl seemed more comfortable dealing with the provable than the speculative. He touched on neurons, their ability to communicate autonomously and how, when computers eventually match human cognitive skills, a sign of their success will be that they're just as unpredictable as we are. If I understood him correctly.
I'm not sure what I was expecting when I met him. Probably someone marked by unfathomable tragedy, as indeed he must be, though he'd probably dispute my characterization of its nature as unfathomable or even mysterious. His optimistic approach seems to be that such things can submit themselves to rigorous analysis, diagnosis and eventual comprehension and eradication.
What was clear is that despite the fate befallen him and his family, his own spirit remains resilient, more life-affirming than most I've encountered. "It's an obligation," he told me. "I find history has given me a responsibility, because the tragedy has evoked so much good will and energy I can't go to my grave feeling I haven't exploited this energy to its maximum potential. I'm here to use that emotion in directions that will minimize the hate that took Danny's life."