Odds & Odds
Jun. 25th, 2007 09:02 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
sniffnoy"What I say is the schedule. What Peter [May] writes down is what he thinks is the schedule." -Paul Sally (approximately)
Category theory is a fucking bulldozer.
I forget when this was, I think it was the class on mapping class groups - "You all know what a ring is, right?" Not everybody does. "OK, a ring is just a Z-algebra."
Babai's class is funny because of the sheer variability of the exercises. I'm not certain that Lawler has given any, I don't think May has given any aside from "Prove that if a functor is full, faithful, and essentially surjective, then it's an equivalence of categories", while Farb has a sheet of (predetermined) exercises handed out at the beginning of each class. But Babai, to quote someone else here (I forget who), just exhales them. And whoever's the scribe for that class has to write them all down. But they range from the completely trivial to the completely ridiculous. OK, there's a lot more of the trivial ones - they're definitely a large majority - but then every now and then he throws in one like "Show there are triangle-free graphs of arbitrarily high chromatic number". (I should note, he occasionally marks some exercises as hard; that wasn't one of them.)
Also, n-Cob is apparently the category of n-1-manifolds, the empty manifold included, where the morphisms are cobordisms up to diffeomorphism, and the product (symmetric monoidal category, remember) is disjoint union.
Today started the actual work part of REU, i.e. why they actually pay us for this. We're going to be teaching these kids, we have to split them into groups based on what they already know and how good they are. So we need to make a diagnostic exam. Fortunately we have many years' worth of diagnostic exams to base ours on, but actually getting a good difficulty spread is troublesome. Meanwhile Sam Raskin keeps trying to put on completely ridiculous problems, while I kept trying to put on too many easy problems, forgetting these kids are 11th-12th graders.
Meanwhile, the apartment.
So my roommates are two first-years, Scott and Satory, both of Broadview, I don't know which specific house. Scott keeps mostly to himself and Satory keeps entirely to himself. I've hardly spoken to Satory, and we never really worked out food with him; he didn't label any of the food he brought, but we were kind of afraid to touch it even so. Well, turns out that was justified. I made a turkey sandwich last night using some bread of his (I had no idea it was his). He knocks on my door this morning asking if I took his bread. So I tell him, look, if you want it to be "your" food rather than the house's, you have to label it. Instead, though, he's gone and claimed entire shelves for himself. I'd worry about him being a leech, but he seems so attached to his property I get the idea he's only going to eat what he himself bought. Of course, I'd much rather be able to use that bread, it was very good bread...
Also, Scott has a polycarbonate glass. Er, cup. YKWIM. Still! Polycarbonate!
Also, Lucas and Seohyung (who is here for the summer and sitting in on many REU classes) apparently live right across the street from me. I didn't realize this until a few days ago.
Hm, what else... wandering! Grant gave me his list of who else is here this summer, but unfortunately, I didn't think at first to look up where they were actually living. So while I figured Friday night I would wander around trying to find people, instead I just ended up wandering around. After that I went and looked up what I could - many of these people have not listed their addresses on Facebook - and made myself a map, so yay. Still, many people don't have their names on their buzzers (before anyone points out that I don't either, I'd like to note that mine doesn't work), so I have to call them on the cell phone, which loses a bit of the impact of just showing up at someone's door and trying to drag them along to find more people. (Think bicycling in Glen Rock, but without the bikes, and without the whole "it actually working yet" part.) Still, with my map firmly in hand, Saturday I packed up some board games for if I found people and Babai's exercises and Dummit & Foote for if I didn't, and ended up at Grant's and Amelia's and Jim's playing Duel of Ages against Grant and a friend of his from home, by the name of Kyle. Grant asks, does it have to be 2 on 1? I say, well, there's rules for a free for all, but I don't know them. I don't know, it can't be that bad... let's try it anyway. Naturally, we quickly found out *why* there are special rules for a free for all (how is a character banished, for instance?), but it worked. It wasn't one of the bloodier games of it I've played, but it was one of the deadlier. Probably has to do with people getting dealt a lot of good melee characters. Also it helped that at one point I sent all 3 of my characters - Frostdancer, Geronimo, and Siennya - to gang up on Grant's Sargeant Gritt. Also great: A lucky roll knocked The Scarlet Fox (one of Kyle's) down to a single health in the very early game. "What happens if I go in that tower?" "That's the Tower of Desperation. You have blue wits so... there's basically a 50-50 chance that you die if you go in there." He went in and survived, but was banished. I should have put him where Grant could attack him again soon, but instead put him where he would be left alone for a while, for some reason I forget; that turned out to be a mistake, unsurprisingly. Grant won, 4-2-2 (by our reckoning of how the score should be counted, anyway).
...yeah, I think that ends this entry.
-Harry
Category theory is a fucking bulldozer.
I forget when this was, I think it was the class on mapping class groups - "You all know what a ring is, right?" Not everybody does. "OK, a ring is just a Z-algebra."
Babai's class is funny because of the sheer variability of the exercises. I'm not certain that Lawler has given any, I don't think May has given any aside from "Prove that if a functor is full, faithful, and essentially surjective, then it's an equivalence of categories", while Farb has a sheet of (predetermined) exercises handed out at the beginning of each class. But Babai, to quote someone else here (I forget who), just exhales them. And whoever's the scribe for that class has to write them all down. But they range from the completely trivial to the completely ridiculous. OK, there's a lot more of the trivial ones - they're definitely a large majority - but then every now and then he throws in one like "Show there are triangle-free graphs of arbitrarily high chromatic number". (I should note, he occasionally marks some exercises as hard; that wasn't one of them.)
Also, n-Cob is apparently the category of n-1-manifolds, the empty manifold included, where the morphisms are cobordisms up to diffeomorphism, and the product (symmetric monoidal category, remember) is disjoint union.
Today started the actual work part of REU, i.e. why they actually pay us for this. We're going to be teaching these kids, we have to split them into groups based on what they already know and how good they are. So we need to make a diagnostic exam. Fortunately we have many years' worth of diagnostic exams to base ours on, but actually getting a good difficulty spread is troublesome. Meanwhile Sam Raskin keeps trying to put on completely ridiculous problems, while I kept trying to put on too many easy problems, forgetting these kids are 11th-12th graders.
Meanwhile, the apartment.
So my roommates are two first-years, Scott and Satory, both of Broadview, I don't know which specific house. Scott keeps mostly to himself and Satory keeps entirely to himself. I've hardly spoken to Satory, and we never really worked out food with him; he didn't label any of the food he brought, but we were kind of afraid to touch it even so. Well, turns out that was justified. I made a turkey sandwich last night using some bread of his (I had no idea it was his). He knocks on my door this morning asking if I took his bread. So I tell him, look, if you want it to be "your" food rather than the house's, you have to label it. Instead, though, he's gone and claimed entire shelves for himself. I'd worry about him being a leech, but he seems so attached to his property I get the idea he's only going to eat what he himself bought. Of course, I'd much rather be able to use that bread, it was very good bread...
Also, Scott has a polycarbonate glass. Er, cup. YKWIM. Still! Polycarbonate!
Also, Lucas and Seohyung (who is here for the summer and sitting in on many REU classes) apparently live right across the street from me. I didn't realize this until a few days ago.
Hm, what else... wandering! Grant gave me his list of who else is here this summer, but unfortunately, I didn't think at first to look up where they were actually living. So while I figured Friday night I would wander around trying to find people, instead I just ended up wandering around. After that I went and looked up what I could - many of these people have not listed their addresses on Facebook - and made myself a map, so yay. Still, many people don't have their names on their buzzers (before anyone points out that I don't either, I'd like to note that mine doesn't work), so I have to call them on the cell phone, which loses a bit of the impact of just showing up at someone's door and trying to drag them along to find more people. (Think bicycling in Glen Rock, but without the bikes, and without the whole "it actually working yet" part.) Still, with my map firmly in hand, Saturday I packed up some board games for if I found people and Babai's exercises and Dummit & Foote for if I didn't, and ended up at Grant's and Amelia's and Jim's playing Duel of Ages against Grant and a friend of his from home, by the name of Kyle. Grant asks, does it have to be 2 on 1? I say, well, there's rules for a free for all, but I don't know them. I don't know, it can't be that bad... let's try it anyway. Naturally, we quickly found out *why* there are special rules for a free for all (how is a character banished, for instance?), but it worked. It wasn't one of the bloodier games of it I've played, but it was one of the deadlier. Probably has to do with people getting dealt a lot of good melee characters. Also it helped that at one point I sent all 3 of my characters - Frostdancer, Geronimo, and Siennya - to gang up on Grant's Sargeant Gritt. Also great: A lucky roll knocked The Scarlet Fox (one of Kyle's) down to a single health in the very early game. "What happens if I go in that tower?" "That's the Tower of Desperation. You have blue wits so... there's basically a 50-50 chance that you die if you go in there." He went in and survived, but was banished. I should have put him where Grant could attack him again soon, but instead put him where he would be left alone for a while, for some reason I forget; that turned out to be a mistake, unsurprisingly. Grant won, 4-2-2 (by our reckoning of how the score should be counted, anyway).
...yeah, I think that ends this entry.
-Harry
no subject
Date: 2007-06-26 06:15 pm (UTC)no subject
Date: 2007-06-27 03:05 am (UTC)no subject
Date: 2007-06-27 03:52 am (UTC)no subject
Date: 2007-07-02 04:20 pm (UTC)Come to think of it, they're nearly ubiquitous in Europe, but I can't specifically remember seeing many in the US.
no subject
Date: 2007-07-02 09:18 pm (UTC)