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Tag Archives: topos theory
The ontological commitment of a sentence is whatever must be among the values of bound variables for the sentence to come out as true. Willard van Orman Quine I bring up this quotation not to agree or disagree with Quine, … Continue reading
http://www.cs.ox.ac.uk/quantum/talksarchive/clap1/clap1chrisisham.avi Is there really such a thing as a point? Well, not really…. Ask any of our undergraduates, why the real numbers? Can you say there’s something √π centimetres away from here?—Well, not really, it’s an approximation….—An approximation to what? “We’re not … Continue reading
Video
December 19, 2011
Tagged Boolean algebra, Boolean logic, C*algebra, category theory, Chris Isham, facts, Feynman integral, Hilbert space, KochenSpecher theorem, locales, Martin Heidegger, math, mathematics, maths, path integrals, philosophy, physics, points, presheaves, quantum mechanics, science, sheaves, topoi, topos theory, toposes
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“Have you ever done acid, kid? This book is like Acid.” —John L. Rhodes, speaking of the book Topos Theory by Peter Johnstone (Source: http://www.amazon.com/gp/product/0521337798?ie=UTF8&tag=hiremebecauim20&linkCode=as2&camp=1789&creative=390957&creativeASIN=0521337798)
Image
May 15, 2011
Tagged acid, algebra, books, category theory, heroes, logic, LSD, math, mathematics, maths, moduli, philosophy, set theory, sheaves, topoi, topos theory, toposes
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The axiom of choice need not hold in a topos, and the law of the excluded middle need not hold. John Baez more, much more: toposes, triples and theories (full book pdf)