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How Computer Scientists Cracked a 50-Year-Old Math Problem (quantamagazine.org)

An anonymous reader writes: Over the decades, the Kadison-Singer problem had wormed its way into a dozen distant areas of mathematics and engineering, but no one seemed to be able to crack it. The question "defied the best efforts of some of the most talented mathematicians of the last 50 years," wrote Peter Casazza and Janet Tremain of the University of Missouri in Columbia, in a 2014 survey article.

As a computer scientist, Daniel Spielman knew little of quantum mechanics or the Kadison-Singer problem's allied mathematical field, called C*-algebras. But when Gil Kalai, whose main institution is the Hebrew University of Jerusalem, described one of the problem's many equivalent formulations, Spielman realized that he himself might be in the perfect position to solve it. "It seemed so natural, so central to the kinds of things I think about," he said. "I thought, 'I've got to be able to prove that.'" He guessed that the problem might take him a few weeks.

Instead, it took him five years. In 2013, working with his postdoc Adam Marcus, now at Princeton University, and his graduate student Nikhil Srivastava, now at the University of California, Berkeley, Spielman finally succeeded. Word spread quickly through the mathematics community that one of the paramount problems in C*-algebras and a host of other fields had been solved by three outsiders — computer scientists who had barely a nodding acquaintance with the disciplines at the heart of the problem.

5 of 96 comments (clear)

  1. Whoosh over my head by baker_tony · · Score: 4, Insightful

    I don't even understand what's been solved!

    1. Re:Whoosh over my head by Anonymous Coward · · Score: 2, Insightful

      I don't even understand what's been solved!

      The answer was 42, so no worries.

    2. Re:Whoosh over my head by drinkypoo · · Score: 3, Insightful

      I don't even understand what's been solved!

      I don't either, but it's worth noting that this is an utterly shit submission; not only does it not give us any clues as to even what kind of problem might have been solved, but there's no informative link which is kind of what the web is all about.

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  2. Layman Terms Please by sycodon · · Score: 2, Insightful

    What practical manifestations will this have?

    Will it enable faster/better/bigger/smaller/higher/lower/longer/shorter/hotter/colder? What?

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    When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
  3. Name drop by RubberDogBone · · Score: 1, Insightful

    Can we please try to name drop some more schools into the teaser?

    I am SURE somewhere we missed somebody's school affiliation that, while having jack shit to do with anything, merits a mention. Surely a janitor who attended night classes at Yale Lock Academy or somebody's third cousin Louis who once had cheese from a shop near Rutgers deserves the same accolades.

    Seriously, why the hell does it matter where all these people went to school and why does this need to be in the teaser? You know what was MISSING from the teaser? A reason why anyone should care.

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