Jason (jcreed) wrote,
Jason
jcreed

There were some leftover concepts from Steve's talk last Friday that I had been meaning to look up on wikipedia and familiarize myself with some more. Mostly it was definitions about bundles and fibrations and covering spaces and stuff like that. In the process of trying to teach myself about them, I stumbled across the definition of Torsors, which besides having an awesome name, are awesome things. They are to groups what affine spaces are to linear spaces. An affine space is a linear space that's forgotten its origin, and a G-torsor is a copy of G that's forgotten where its identity is. Actually what it is is a set X with a G-action that is "free" and "transitive", which as far as I can tell are funny ways of saying "injective" and "surjective". I mean, if you fix an element of x, the group action is just a function, and I think that's what the definitions come out as. Anyway these things that baffle one's otherwise concrete notions about distinguished elements of algebraic structures by sort of quotienting over the whole issue always fascinate me.
Tags: math
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    Didn't sleep well. Long day of work. Dinner with akiva at hanamichi.

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    K was going to do a thing for her dad's birthday, but scheduling kept slipping and slipping so I guess we're going to try doing it tomorrow instead.

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    Had a pleasant lunch with paul and gabe back from working-at-facebook times. Discussed the important issues of the day, by which I mean video games…

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  • (no subject)

    Didn't sleep well. Long day of work. Dinner with akiva at hanamichi.

  • (no subject)

    K was going to do a thing for her dad's birthday, but scheduling kept slipping and slipping so I guess we're going to try doing it tomorrow instead.

  • (no subject)

    Had a pleasant lunch with paul and gabe back from working-at-facebook times. Discussed the important issues of the day, by which I mean video games…