1. I have had to spend some time each day when I would otherwise be grading, instead continuing my search for housing in Ann Arbor. Yay.
2. Geometry is tiny this year. Very few people going. That's unusual. I'm told in the past few years the course has been made much easier since back in '04 and '05 when I took it? We've been going around encouraging second-years to take it. I guess technically I shouldn't say that, but it's been so blatant that people have noticed easily.
3. Combinatorics with Henry Cohn has been pretty cool so far. So far in class has been mostly stuff I know, unsurprisingly, but it's going quite fast, and already on the psets there's stuff I haven't seen before. (I really have not done enough combinatorics!) He introduced generating functions, and then demonstrated them by giving a GF proof of Vandermonde, on the very first day. There seem to be quite a few first-years there, which, given the above, kind of surprises me. Also it looks like he's giving away number theory stuff on the psets? Oh well, not nearly as bad as a guest lecture giving away number theory stuff.
4. More on combo: The first pset. (I'm grading for combo.) One section was, you were given a bunch of sums involving binomial coefficients, and told to simplify them as much as possible.
Problem 4: sum from k=0 to m of (n choose k)
Problem 5: sum from k=0 to m of (-1)^k (n choose k)
Problem 7: sum from k=0 to m of (n choose k)(n/2-k)
Lots of people's response to these problems, were to think the 'm' was a misprint and he meant n. Of course, these are easy for m=n. It's not like 5 & 7 are so hard for m≠n, but I think lots of people didn't even think to try it. This resulted in many "THIS SAYS M, NOT N" comments from the people grading those problems.
Ah, but what about problem 4? That must have been a mistake, surely? No, it was just an exercise in reading the instructions. It said to simplify as much as you can, not that you'd actually be able to simplify any further.
Also, problem 6: sum from k=0 to n of (2k choose k)(2(n-k) choose n-k). OK, it's 4^n, this is pretty easy with generating functions. But though I could swear I'd seen Tom give a combinatorial proof of this before, I couldn't recall it, and neither me nor any of the other counselors were able to come up with one, nor were any of the students who were doing the set. I think we all tried the approach of, interpret 4^n as 2^2n, consider subsets of a 2×n rectangle... and then do what with them? I don't know; I couldn't find any interpretation that led to the above sum. Tom, do you actually know one? Does anyone else?
5. Boardgames. Man do we have a lot of boardgamers here this year - not necessarily ones who would call themselves such, I mean, but ones who are willing to play and actually find it fun. Tim, Erick, and I played a game of Nexus Ops, and it got a lot of attention, and perhaps more importantly, actually led to 3 other people just borrowing the game and playing later. I've brought, in addition to the usual small stuff, my Icehouse pieces, Pow Wow (which Jerry has of course gone arond promoting), Nexus Ops, Traders, AGoT, and Scotland Yard. Will has brought Settlers, Bang!, and Illuminati, and Gavi[3] (a first-year) has brought Puerto Rico. Also Gavi insists we play AGoT tomorrow, and, you know, I think we might well be able to find players. Josh, you gonna show up? :)
Speaking of Scotland Yard: Yikes. Had a bad game of that today. I started a game with 6 players, Will as Mr. X, the detectives being me, Watson, Erick, Hong (a first-year), and another first-year I forget. We were originally going to play Nexus Ops, but then Watson and Erick arrived and we decided to play something that could support 6 instead. Unfortunately, Hong's English isn't very good, so it was not a good idea to have him play something so discussion-heavy, unless he was going to be Mr. X, anyway. Meanwhile, the detectives' planning typically takes a while in Scotland Yard, but here it dragged on *really* long, largely, I think, due to Watson's insistence on analyzing everything way beyond the point where, uh, there's a point. OK, not exactly true: I wouldn't be surprised if his analyses did help our game. But what they also did was take so long that the two first-years got up and left, and several moves later, the rest of us eventually decided we just didn't care about the game anymore and just stopped.
6. It's fun having Tim as a JC. :D
7. Here's something very out of the ordinary: A student not arriving until Thursday night. We didn't find out until after it was too late to tell her, no, you really have to be here the first few days. I really have to wonder how she's going to catch up, though I expect she'll manage somehow.
8. Around the first day or so, Sam Lite pulled off an unofficial room switch with Irving (a first-year), putting him in the same room as Ian Choi, another returning student. My initial reaction was that "Well, I guess it's against the rules, but I don't see any harm"; but, well, I was wrong - it splits up my students, it puts two returning students together, and if other people were to go switching their rooms, well, it would be chaos, and there would be little correlation between the location of a counselor's room and those of his students. I believe he's switched back now that we've pointed out that he has to by the rules, though the names on the doors have not been switched back. :-/
-Harry
[0]I guess most people call it the A/C lounge, but I've taken to just calling it the "C lounge". Because of its location, I mean.
[3]Short for "Gavriel".
[4]Another first-year, of course.
2. Geometry is tiny this year. Very few people going. That's unusual. I'm told in the past few years the course has been made much easier since back in '04 and '05 when I took it? We've been going around encouraging second-years to take it. I guess technically I shouldn't say that, but it's been so blatant that people have noticed easily.
3. Combinatorics with Henry Cohn has been pretty cool so far. So far in class has been mostly stuff I know, unsurprisingly, but it's going quite fast, and already on the psets there's stuff I haven't seen before. (I really have not done enough combinatorics!) He introduced generating functions, and then demonstrated them by giving a GF proof of Vandermonde, on the very first day. There seem to be quite a few first-years there, which, given the above, kind of surprises me. Also it looks like he's giving away number theory stuff on the psets? Oh well, not nearly as bad as a guest lecture giving away number theory stuff.
4. More on combo: The first pset. (I'm grading for combo.) One section was, you were given a bunch of sums involving binomial coefficients, and told to simplify them as much as possible.
Problem 4: sum from k=0 to m of (n choose k)
Problem 5: sum from k=0 to m of (-1)^k (n choose k)
Problem 7: sum from k=0 to m of (n choose k)(n/2-k)
Lots of people's response to these problems, were to think the 'm' was a misprint and he meant n. Of course, these are easy for m=n. It's not like 5 & 7 are so hard for m≠n, but I think lots of people didn't even think to try it. This resulted in many "THIS SAYS M, NOT N" comments from the people grading those problems.
Ah, but what about problem 4? That must have been a mistake, surely? No, it was just an exercise in reading the instructions. It said to simplify as much as you can, not that you'd actually be able to simplify any further.
Also, problem 6: sum from k=0 to n of (2k choose k)(2(n-k) choose n-k). OK, it's 4^n, this is pretty easy with generating functions. But though I could swear I'd seen Tom give a combinatorial proof of this before, I couldn't recall it, and neither me nor any of the other counselors were able to come up with one, nor were any of the students who were doing the set. I think we all tried the approach of, interpret 4^n as 2^2n, consider subsets of a 2×n rectangle... and then do what with them? I don't know; I couldn't find any interpretation that led to the above sum. Tom, do you actually know one? Does anyone else?
5. Boardgames. Man do we have a lot of boardgamers here this year - not necessarily ones who would call themselves such, I mean, but ones who are willing to play and actually find it fun. Tim, Erick, and I played a game of Nexus Ops, and it got a lot of attention, and perhaps more importantly, actually led to 3 other people just borrowing the game and playing later. I've brought, in addition to the usual small stuff, my Icehouse pieces, Pow Wow (which Jerry has of course gone arond promoting), Nexus Ops, Traders, AGoT, and Scotland Yard. Will has brought Settlers, Bang!, and Illuminati, and Gavi[3] (a first-year) has brought Puerto Rico. Also Gavi insists we play AGoT tomorrow, and, you know, I think we might well be able to find players. Josh, you gonna show up? :)
Speaking of Scotland Yard: Yikes. Had a bad game of that today. I started a game with 6 players, Will as Mr. X, the detectives being me, Watson, Erick, Hong (a first-year), and another first-year I forget. We were originally going to play Nexus Ops, but then Watson and Erick arrived and we decided to play something that could support 6 instead. Unfortunately, Hong's English isn't very good, so it was not a good idea to have him play something so discussion-heavy, unless he was going to be Mr. X, anyway. Meanwhile, the detectives' planning typically takes a while in Scotland Yard, but here it dragged on *really* long, largely, I think, due to Watson's insistence on analyzing everything way beyond the point where, uh, there's a point. OK, not exactly true: I wouldn't be surprised if his analyses did help our game. But what they also did was take so long that the two first-years got up and left, and several moves later, the rest of us eventually decided we just didn't care about the game anymore and just stopped.
6. It's fun having Tim as a JC. :D
7. Here's something very out of the ordinary: A student not arriving until Thursday night. We didn't find out until after it was too late to tell her, no, you really have to be here the first few days. I really have to wonder how she's going to catch up, though I expect she'll manage somehow.
8. Around the first day or so, Sam Lite pulled off an unofficial room switch with Irving (a first-year), putting him in the same room as Ian Choi, another returning student. My initial reaction was that "Well, I guess it's against the rules, but I don't see any harm"; but, well, I was wrong - it splits up my students, it puts two returning students together, and if other people were to go switching their rooms, well, it would be chaos, and there would be little correlation between the location of a counselor's room and those of his students. I believe he's switched back now that we've pointed out that he has to by the rules, though the names on the doors have not been switched back. :-/
-Harry
[0]I guess most people call it the A/C lounge, but I've taken to just calling it the "C lounge". Because of its location, I mean.
[3]Short for "Gavriel".
[4]Another first-year, of course.
