From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: <393394D0A7F3F4A227F94CDA@192.168.1.2> References: <7d3530220909050736h693c665ere5b8346c4569c7e1@mail.gmail.com> <3aaafc130909052123h2dacb56ck99d6a5302f972ae0@mail.gmail.com> <393394D0A7F3F4A227F94CDA@192.168.1.2> From: Rob Pike Date: Sun, 6 Sep 2009 11:03:12 -0700 Message-ID: <7359f0490909061103y78cfb3a4u8adf56d062e63695@mail.gmail.com> To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: text/plain; charset=ISO-8859-1 Subject: Re: [9fans] nice quote Topicbox-Message-UUID: 66ae7b78-ead5-11e9-9d60-3106f5b1d025 > Are you implying Doug McIlroy hadn't been taught about (and inevitably > occupied by) Church-Turing Thesis or even before that Ackermann function and > had to wait to be inspired by a comment in passing about FORTRAN to realize > the importance of recursion?! This was a rhetorical question, of course. Doug loves that story. In the version he told me, he was a (math) grad student at MIT in 1956 (before FORTRAN) and the discussion in the lab was about computer subroutines - in assembly or machine language of course. Someone mused about what might happen if a subroutine called itself. Everyone looked bemused. The next day they all returned and declared that they knew how to implement a subroutine that could call itself although they had no idea what use it would be. "Recursion" was not a word in computing. Hell, "computing" wasn't even much of a word in math. Don't be Whiggish in your understanding of history. Its participants did not know their way. -rob