From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/3100 Path: news.gmane.org!not-for-mail From: "John Baez" Newsgroups: gmane.science.mathematics.categories Subject: Re: cracks and pots Date: Tue, 14 Mar 2006 11:56:09 -0800 (PST) Message-ID: <200603141956.k2EJu9625544@math-cl-n03.ucr.edu> NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1241019094 7253 80.91.229.2 (29 Apr 2009 15:31:34 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 29 Apr 2009 15:31:34 +0000 (UTC) To: categories@mta.ca Original-X-From: rrosebru@mta.ca Tue Mar 14 19:03:56 2006 -0400 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 14 Mar 2006 19:03:56 -0400 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.52) id 1FJIXu-00042Y-6h for categories-list@mta.ca; Tue, 14 Mar 2006 19:03:18 -0400 X-Mailer: ELM [version 2.5 PL6] Original-Sender: cat-dist@mta.ca Precedence: bulk X-Keywords: X-UID: 46 Original-Lines: 67 Xref: news.gmane.org gmane.science.mathematics.categories:3100 Archived-At: Hi - > I just came across the following pages > > http://motls.blogspot.com/2004/11/category-theory-and-physics.html > http://motls.blogspot.com/2004/11/this-week-208-analysis.html > > written by Lubos Motl, a physicist (string theorist). Some of you may find > these articles interesting and probably revealing. > > Are we category theorists as a whole going to quietly accept getting > discredited by a minority of us presumably applying category theory to > string theory? I can't tell if you're kidding. I'll assume you're not. There's nothing wrong with applying category theory to string theory. The papers by Michael Douglas and Paul Aspinwall cited above by Motl are some nice examples of using derived categories to study D-branes. Further examples: the Moore-Seiberg relations turn out to be little more than the definition of a balanced monoidal category, and the Segal-Moore axioms for open-closed topological strings are nicely captured using category theory here: http://arxiv.org/abs/math.AT/0510664 There were a lot of nice talks on the borderline between category theory and string theory at the Streetfest. Perhaps more to the point, Lubos Motl is famous for his heated rhetoric. He doesn't like me, or anyone else who criticizes string theory. The articles you mention above are mainly reactions to my This Week's Finds. He's actually being very gentle - for him. He even says "the role of category theory can therefore be described as a `progressive direction' within string theory". I'm sure you'll all be pleased to know that. :-) > It is surely not too late to react and point out that this is > not what (all of) category theory is about. I would urge everyone not to react - at least, not until they are well aware of what a discussion with him is like. See his blog and his comments on Peter Woit's blog if you don't understand what I mean. For example: http://pitofbabel.org/blog/?p=51 > Please give a thought about what > we, as a community, can urgently do to repair this damaging impression. Since Motl's personality is well known, any damage will be minimal. I think we should relax and take it easy. Best, jb