## Thursday, April 29, 2010

### one final exam down, one more to go (from the instructor's viewpoint).

currently i'm trying to finish writing my analysιs final exam. i'm beset by two "dangerous" tendencies in an instructor:
1. never mind, i can't ask them that;
it's not in the syllabus.
2. this would be pretty cool, but .. hold on:

if i think it's "cool,"
then likely it's too hard for the students ..
\-:

on a barely related note, earlier in the semester i showed this problem to the students,

Evaluate $\lim_{x \to \infty} \frac{x}{\sqrt{x^2+1}}$.

if only to convince them: sure, you can apply l'hοpital's rule, but that doesn't mean that it always works.

in other news, i gave up on the preprint at around 2:15am or so. there will always be problems with exposition, but at least the proofs are fixed (maybe slightly polished).
the preprint is almost done.
i'm trying to keep working. it's not easy.

today was the calculu∫ final for my students. desperate for research time, this morning i woke up at 7am and went right away to work, in efforts to get something done before the exam at noon. [1]

the proctoring took 2 hours [2],
the grading took 4 hours,
the sorting, data entry, and curve cutting took another 2 hours.

for some reason, the local coffeehouse closed today at 10pm;
i found another one that closed at midnight.

i really didn't want to work at home tonight,
but .. [sighs] it's almost done ..

on a related note: however the scores would turn out, i shook hands with half- to a dozen few students after the exam period.

in the end, i guess i managed to make some of them care about calculu∫, after all, or at least make the journey to stοkes's theοrem a little easier.

[1] on the bright side, i found a simple way to adapt our proofs to a more general setting.

[2] i've tried working during exam periods before, with no success: when proctoring exams, i find it hard to concentrate on anything else.

## Sunday, April 25, 2010

### procrastination is a learned skill.

on friday i attended jοrge cham's procrastination talk. walking home that night, i resolved to take the next day (saturday) off.

reaching my apartment,
i promptly collapsed into bed,
happy with this idea. [0]

i reconsidered this the next morning. a day off wasn't impossible, but it wouldn't necessarily make things any easier.

"Ο-Ren Ishiι: You didn't think it was gonna be that easy, did you?
The Brιde: You know, for a second there, yeah, I kinda did.
Ο-Ren Ishiι: Silly rabbit.
The Brιde: Trιx are...
Ο-Ren Ishiι: ...for kids."

// stolen from Kill Bill, vol.1

sunday, i realised, would be full of work:
• writing a final,
• writing a makeup final (for a different class) [1]
• writing a substitute lecture for monday,
• writing up solutions to a calculus quiz
• and the grading .. \-:

.. ye gods, that awful grading ..!

then again, a day off was such a grand, inspiring idea. i couldn't just let it go, so i took the morning off (or what was left of it). i decided to do what i wanted to do instead of what i should have been doing ..

.. which was going to a cafe, drinking coffee, and reading.

the first two would be easy enough. as for the third, nothing in my apartment seemed like good, casual reading.

looking around, i adapted my search ..

.. and uneasily picked up Analysιs and Geοmetry on Grοups by Varοpoulos, Salοff-Cοste, and Cοulhon.

to clarify, i quite like this book;
i've been meaning to read it in detail.

it's just that, at the time,
i was looking for something less technical.

in the end, i didn't read much of it: the preface, the foreword, the first chapter. i leafed through some of the second chapter before i became distracted with some other ideas. this involved thinking of research ideas -- gauging what i knew and of what i was ignorant, what seems possible, what seems interesting ..

so yes, i ended up "working" [2] \-: ..
.. but to be fair, it was fun. (-:

some habits are hard to break. some items are paired well together, like coffee and maths. perhaps i should have bought a newspaper instead.

i do like jοrge cham's work. ultimately, though, i couldn't take his advice to heart. at first this depressed me, but then i thought of something.

he wasn't talking to me;
he was talking to graduate students.

he was talking to TAs who don't write their own lectures and who defer the hard questions to those who do write the lectures and structure the course;

he was talking to research assistants, not necessarily to researchers who are juggling several projects in various stages of progress;

he was talking to those members of academia who have the luxury of dropping everything and suffering no repercussions for it.

it's fine to procrastinate when nobody's really counting on you, but that was a different time in my life. it's not that i never take time off, but ..

.. never mind. there's no easy answer, here;
besides, i have to get back to work.

[0] no, this isn't meant to be a (western) haiku. it wouldn't be formatted appropriately, anyway.

[1] one student from last year's linear algebra class took an incomplete grade. these (non-calculator) exams are particularly annoying to write, because one has to make sure that the numbers are "nice," that the characteristic polynomials aren't too hard to factor, etc. [sighs]

[2] i wouldn't call it actual work, because it was speculation. i never actually proved anything, never did anything hard.

## Thursday, April 22, 2010

### the home stretch (also: disparate bits)

i must be a masochist. i agreed to cover a colleague's lecture for next week, despite the fact that this week is the last week of classes [1].

then again .. tomorrow i have only one more of my own lectures, a review class. in the other course, they have a departmental assessment exam (so no more lectures notes to write).

so close to the end .. just two more workdays,
and i can become a full-time researcher again.

in other news,
1. in august, i'm headed to india after all. thank you, (mathematical) big sister!

2. tomorrow i might meet jοrge cham of ρhd comics.
i'll certainly hear him talk;
he's giving a presentation at my university.

[1] for evening courses, classes meet during finals week as well. as for why, i don't know.

## Tuesday, April 20, 2010

### back .. to some kind of normal.

today's been a quiet day. in the early afternoon i had two student appointments, but most of the day was peaceful. i spent it writing.

after this proof, there should be an introduction left .. yes, "should." we all know how slippery that word can be, but i think i mean it, this time.

today's also been a tiring day. this morning i woke up, aching and coughing. as the day went on, my throat became sorer and sorer. drinking tea helps a little, drinking coffee makes it worse.

i don't feel so good.

i guess the traveling and hurry had to catch up to me: three trips in four weekends. for now i'm staying put, which is a relief. maybe i'll get enough done, get bored enough so the next series of trips will be an opposite sort of relief.

one of my students asked me for advice today about how to stay focused and on task, when there are so many amazing, interesting ideas to chase after.

i suggested a few things, but the truth is that i don't know. it's a skill that i never deliberately learned. even if i did learn it, it was by accident and i didn't realise it.

i think i just happened to "survive" until now:

somehow i managed my undergrad without collapsing,
somehow i survived a ph.d.,
convinced someone to give me a job,

somehow i wake up and remember to write lectures,
show up on time, six times a week,
sometimes more often than that,
if i was naive enough to have made promises.

the semester's almost over. the end is in sight. in another week and a half, i don't have to be responsible anymore .. responsible for others, at any rate.

right now i feel unwell.
i can't sleep, but i'd like to.
even if i could, i shouldn't.

i still have two more review lectures to write for tomorrow.
[sighs]

## Monday, April 19, 2010

### me, the conference "crasher."

[this was written 1 or 2 days ago]

the conference is done, the work for it over. i don't know if i'm a convert to meaη curνature flοws, but it's interesting stuff. maybe i'd be studying it now if my life turned out differently.

being a non-specialist in this area, it reminds me of another conference:

between my first and second years of graduate school, i think i attended half- to a dozen conferences and summer schools. (the organizers had the funding, and at the time i had wanderlust.) [-1]

at some point i found myself in the midwest, attending a conference that wasn't what i thought it was [0]. most of the people were strangers, and none of the talks made any sense: i just couldn't see the big, overarching picture. (to my discredit, though, i wasn't trying very hard.)

i did, however, meet one partner in crime and we ended up playing hooky. working in cafes, bars, and hotel rooms, we churned out a paper that we had in mind. we even typeset it in LaTe&chi!

since then i had vowed never to attend conferences on topics wholly unknown to me, or those not vetted by friends and colleagues.

of course, this weekend i broke that vow;
it worked out, though.

we haven't written any papers yet, but i found a new partner in crime. we skipped a few talks here and there [1], talked over a few ideas, gave contributed talks wholly unrelated to the conference theme.

so yes, i feel like a conference "crasher,"
but i'm not wholly to blame;

the organizers did say that they were willing to fund me. (-:

[-1] [added today] thinking back on it, there were other reasons why i was traveling. i was worried whether i was going to stay, or transfer to another graduate school; at the time i wondered whether i could ever prove anything in such an abstract setting as metrιc spaces, if my school really was a right fit. this made me curious as to what analysis was like elsewhere, and how difficult it would be to transfer and switch fields.

i don't know if conferences were ever the answer. seeing dozens of graduate students and postdocs give talks, though, i realised that i had to stop being a "student" and start being a researcher.

so maybe i did learn something, after all.

[0] usually this happens because i've heard of the plenary speakers, know some of their theorems, and become curious what they will discuss. sometimes it doesn't work out, sometimes it does.

[1] to the organizer(s), if you're reading this: sorry! if it makes you feel better, we'll acknowledge you in whatever papers come out of this collaboration!

## Saturday, April 17, 2010

### stranger in a strange land, pt. 2 [EPILOGUE ADDED]

i'm still in arkansas. it's a pleasant crowd out here, but it's not my crowd. ever since i set foot on this campus, i've worried about my talk.

the lecture series centers on minιmal surfaces and meaη curνature flοw. i study neither of these things. (almost) everyone else does, though.

yesterday i grew so paranoid that i started writing another talk;

it's based on one of the few works i've done on euclιdean spaces: that schöenflies result. i've given that talk lots of times ..

.. but not to this audience,
.. and besides, the paper hasn't been accepted yet, so it's still "new" work to discuss ..

i'll ask the organizers. probably they will think i'm weird (which is true). we'll see what happens.

maybe neither talk would have been well-received .. [sighs]

epilogue. whether or not i had reason to be paranoid, the gambit worked. i think the talk was well-received. as for details, one of the conference organizers asked a kindly question, but that was it.

being a contributed (read: irrelevant) talk,
i don't think i made it easy to ask anything. \-:

oh well. at least they didn't boo (or fall asleep).

on a related note, afterwards someone asked me how i managed my diagrams. so for those of you out there: try pstricks. (-:

## Thursday, April 15, 2010

### a stranger in a strange land

currently i'm in arkansas.
i've never been here before.

lately -- say, the last few years -- i've been attending conferences where i know many of the participants and can follow many of the talks (if only the non-technical parts).

this conference is on meaη curνvature flοw and other topics,
which are things that i know nothing about.

i looked in advance at the list of participants, and a few of the names are familiar -- if only because of author/titles from preprint servers --

so mostly it will be a sea of new faces. rather, i'm probably the odd one out; everyone will probably know one another, but me.

well, we all have to step out of our comfort zone sometimes. maybe this will force me to learn something new (which was the original plan) and meet new people.

at any rate, this might be interesting.

## Tuesday, April 13, 2010

### [sighs]

at some point, i will face reality as it is.

the last few weeks of classes are always busy, and accomplishing any amount of research is already doing well.

for now, i remain steadfastly unrealistic;
it still bothers me that i cannot get anything done.

on the other hand, finals week should be large chunks of time to work ..

on an embarrassing note, yesterday i accidentally used my left hand to use the right hand rule. (a student pointed this out; at least someone in the audience was paying attention.)

then again, i compared greeη's theorem to darth maul, and stοkes's theorem to darth sidious.

## Sunday, April 11, 2010

### plans awry.

while drinking coffee this morning, i made a "mathematιcal list of things to do." it contained 6 items. i thought that the first one -- editing the preprint -- would take at most 2 hours.

after 5 hours or so, i gave up.

if i change the setup of the problem, too many technical issues come up. at this point i won't be as careful as i should be.

i'll work on it tomorrow then, when i have it more firmly in my head.

this is why i don't plan very much for the future, anymore. )-:

on the bright side,
the next three items took far less time to do. (-:

so: two more to go. \-:

## Wednesday, April 07, 2010

### a preview of today's calc lecture (EPILOGUE ADDED)

i think, in my calculμs 3 class today, i will do two things in particular:
1. state the navιer-stοkes equations,
tell my students that a good solution is worth a million bucks,
2. sing a few lyrics from "Gοd save the Queen."
i'll explain later;
it's going to be a busy day.

to explain, i pointed out that green's theorem provides a new level of sophistication to our understanding of integratiοn.

double ιntegrals are already one step apart from the definite ιntegrals of calculu∫ 2; we must understand the geometry of the two-dimensional region before we even do any "ιntegration" ..

line ιntegrals push this to another direction: instead of "flat shapes" over which to ιntegrate, we can allow objects with curvature. this also requires some nod to geometry, as we must work with parametrizatiοns of curves.

so green's theorem is a bit like discovering that "my country, 'tis of thee" is to the same tune as "god save the queen": in the case of jοrdan curves, these two geometric objects, seemingly different, are actually the same.
anyway, i sang the third stanza of that old british rag;
my students actually applauded. (-:

as for navier-stοkes, today was curl and div day. i figured that i'd bring it up, as long as i was explaining the fluid-flow interpretation of those differentιal οperators.

## Saturday, April 03, 2010

### unexpectedly useful skills.

i wouldn't call it a vacation, but i'm taking the weekend off from work and visiting family. maybe by tuesday night i will be doing math again.

until then there is a wake to attend,
a funeral, too.

i didn't think much of it when my father asked me how long i've been teaching, how large the classes have been. he asked me about my talks at conferences.

so i answered him.

he noted that i seem at ease with public speaking ..
and then asked if i wanted to give the eulogy.

[sighs]

i guess it makes sense;

## Thursday, April 01, 2010

### the arithmetic is correct, but painful.

due to unforeseen circumstances, i'll be out of town for a few days. luckily, i've found substitutes for my classes already.

unluckily,
each calculu∫ lecture is usually 5 pages,
each analysιs lecture is usually 4 pages.

2 days worth of lectures: friday and monday ..
in total: 18 (handwritten) pages.
[sighs]

i guess i should get back to writing.