Happy Halloween.

I'm dressing as a slightly befuddled graduate student. I have the mannerisms down just so: right hand pushes hair back while thinking, eyes staring off into the distance, slight drumming of the right heel. Jeans, t-shirt, and some sort of sweatshirt for warmth. I figure I should occasionally take a break to get coffee or lend someone in hand, just to stay in character.

I also considered dressing as a house plant. But that costume would have required taking greenery away from the plants on my desk. I don't really water them as often as I should, and I think that taking any of the (unwilted) leaves from this poor White Butterfly Nepthytis would just about do it in.

The math colloquium today was given by Prof Barenblatt, on the topic of mathematical modeling of turbulence. I didn't follow all the details (I rarely do in an actual talk), but I followed the general theme. And I was tremendously amused. Something about the combination of his personal presentation style and the thick Russian accent tickled me.

A quote that I found particularly entertaining:

When we submitted this paper, one of the reviewers wrote I believe the publication of this paper will severely damage the reputation of the authors. It should therefore be published immediately. The editor, upon some consideration, decided that counted as an approval, and the paper was duly published.

And now I've returned home, and it's time for some rice pudding and the beginning of the evening's exertions.

I made an Amazon order today. Why? I wanted to get another book on perturbation methods, since they seem to be showing up with increasing frequency in my recent research endeavours, and since they're showing up in class as well. That was just the excuse I needed. I picked up a few other books from my wish list as well, though I've taken less time to read recently, so that my queue is perilously full. The books are:

• Perturbation Methods by E.J. Hinch -- a concise, mathematically-oriented treatment
• Simple and Direct by Jacques Barzun -- on writing style
• The Culture We Deserve by Jacques Barzun -- cultural criticism essays
• Moving Toward Stillness by Dave Lowry -- essays on the Japanese martial arts
• Alistair Cooke's America by Alistair Cooke -- a history by the BBC correspondent

Back to the code.

People who take measurements of physical artifacts do some amazingly clever things. I went to a meeting on Thursday where there were two talks. The first talk was about measurements of the waves going through a high frequency piezoelectric resonator. Think of waves rippling across the surface of a drum. Now think of trying to measure the shape of those waves -- when the drum is only tens of micrometers across, the surface of the drum moves only a few nanometers, and about two billion waves pass through a point in one second. It seems more fanciful than trying to count how many steps are made by a collection of angels furiously tap-dancing on the head of a pin. But by bouncing a laser off a mirror sitting atop an atomically sharp tip on the drums surface, the first speaker managed to measure the shapes of those waves with startling accuracy. The second speaker was working on building and tuning the types of devices that the first speaker measured. I think both the construction and the measurement are awe-inspiring.

The fact that we understand as much about fluid dynamics as we do is equally awe-inspiring, though in a different way. So much nonlinearity! I spent some time Friday afternoon photocopying the fluids notes on reserve in the library. I copied most of the material after the basic tensor calculus and continuum mechanics at the beginning of the course; at the end, I had exactly a hundred pages of material. It will be a good supplement to reading the text by Batchelor.

I went with Winnie to the UC ballroom dance Fall Ball on Friday. I'm not much of a dancer, and doubt I ever will be. It turns out that Winnie feels much the same, but it was a chance to catch up with old friends and to get dressed up. I hope that the dance made up for the time she spent in traffic; the traffic from the South Bay to the East Bay is apparently surprisingly dense on a Friday afternoon.

Yesterday, we walked along the Golden Gate Bridge. It was a good day for such a walk. We're experiencing a final burst of hot weather, and the breeze from the Bay somewhat balanced the heat of the sun. The bridge really does offer some postcard views. It's possible to see so much in one glimpse: the buildings of San Francisco, the hills of the East Bay, the woods of the park at the San Francisco side, and the boats sailing out of the docks on the Sausalito side. It takes only a little imagination to see the hills and water and trees, to see how it attracts so many residents, and to see how powerful the geological forces that shaped the region must be. The bridge itself is interesting, too, but the structure doesn't compare to the landscape. Actually, we passed three bridges yesterday: the Bay Bridge, the Golden Gate Bridge, and the Richmond Bridge. All are interesting in their own ways.

There is a book by William Gibson, Virtual Light, in which much of the action takes place on the Bay Bridge, in a future in which, after an earthquake made it undriveable, people wandered onto the bridge and made it a sort of city unto itself. I was reminded of it a little yesterday.

It was another good weekend for food, too. I made ham and white bean soup on Friday night, and had eggs scrambled with ham and onions for brunch on Saturday. On Saturday night, we had a mushroom-spinach stuffed crust pizza from Zachary's Pizza, and this morning there were bagels from Noah's Bagels, which Patxi and Esther picked up. We finished off the Monk's Blend tea on Saturday night, too; I think I will have to get some more. I also continue to enjoy having an occasional bowl of yogurt and raisins with honey and cinnamon. And there is a baguette in the kitchen which seems to be calling my name now. Ah, food.

Daylight savings time ended last night, and I have turned back all the clocks except the one on my laptop. At some point, I will convince the computer to change its clock as well, but right now it doesn't seem worth the bother. Linux keeps a software clock which is semi-independent of the hardware clock, and so changes I make to the clock setting seem to get lost when I put my machine to sleep. It's probably an easy thing to correct, but it's easy enough to subtract an hour mentally, too.

• Currently drinking: Coffee

The PDE midterm, a three-problem take-home exam, was assigned this afternoon. I solved the problems and wrote solutions this evening. The questions were indeed about the same level as most of the homework, which is to say they were a good deal more humane than the problems for many classes I've taken. That still leaves me with too many tasks in my queue -- trying further to debug a particularly vexing code, running resonator simulations, learning how to solve problems involving elastic waves in a half space, and maybe computing polynomial coefficients from roots with high accuracy. It's all great fun.

I also plan to go to a dance with Winnie tomorrow. I don't know how to dance, but that's okay. And on Saturday we'll make pumpkin-based foods. Perhaps I'll have some time to read this weekend, too. If I do so, I'm not sure whether I will read more from Quicksilver or whether I'll read something technical (about fluids, statistical mechanics, microstructural defects, elastic waves, or Laguerre's iteration).

And I'll have some time to sleep, too. Come to think of it, I have some scheduled time to sleep right now.

Some days I drink tea as an excuse to have time to write. Some days I write as an excuse to have tea. Some days I have tea because I was missing ingredients for dessert; some days I have tea with dessert. Some days I miss tea altogether; maybe I have coffee, or just water.

Vince and I have a recent running joke that his guinea pig would be a perfect graduate student. She's shy, and likes to hide in dark places; she gnaws on electrical cabling; and she would probably join any movement that offered free food. But, alas, I've decided I don't think most guinea pigs would be good graduate students after all. They have too high a self-preservation to curiosity ratio.

• Currently drinking: Earl Grey

The most recent SIAM Review arrived in the mail today. This looks like a particularly interesting issue for the articles alone, but since the book reviews are shorter I read them first.

The book reviews this time are particularly amusing. There's a two-volume set on scattering that goes for $1000 -- and I complain about the price of text books at a tenth that cost! There's a review of a book on ethnomathematics which describes such things as binary codings used in various divination systems; graph theoretic properties of social networks among the Basques; and the calendar system of Bali, which apparently uses overlapping weeks of length 1, 2, ..., 10 days. Then there's a review of a book on nonlinear dynamics which includes a quote from the Roman poet Lucretius in which the poet appears to be grappling with the concept of a nonlinear flow. There's also a book on nonlinear dynamics which the reviewer recommends as an applied math book that I strongly recommend for sharing with your students and lovers, patrons and presidents (the book is SYNC: The Emerging Science of Spontaneous Order by Steven Strogatz). I'd send Mr. Bush a copy, but I think I know other people who would appreciate it more.

• Currently drinking: water

The computer is generating quadrature rules, and I'm going in circles debugging. I take great comfort in the thought that my computer is doing something useful even if I'm stuck.

Lunch yesterday was courtesy of the CS faculty. Every Monday, they have a lunch meeting that goes from 12-1; and every Monday around 1, the graduate students raid the leftovers. Yesterday was Mexican food, and it was quite good. And for recess? I walked to the top of Solano last night and bought a copy of Neal Stephenson's Quicksilver. I thought I might read for an hour or two before I went to bed last night, but the walk was sufficiently invigorating that I had energy to keep working until around midnight. At that point I fell asleep before I could even think about reading.

• Currently drinking: green tea

Despite my best intentions, I did not print transparencies before my talk on Friday. Fortunately, the laptop projector worked fine. The talk seemed well-enough received, and in any case is now presented and past.

Winnie and I spent Saturday afternoon at Lake Elizabeth in Fremont. We paddled around the lake in a boat for a little while, and spent some time walking around. We played on the swings for a few minutes, and contemplated playing on various other things in the playground. Not every playground toy scales as well as a swing -- a six-foot slide doesn't work so well for a slider just over six feet -- but it was fun nonetheless.

Returning from the BART station in El Cerrito, I encountered a gentleman wandering barefoot along the sidewalk, drinking something that smelled like paint thinner from what looked like a pickle jar. As I walked past, he said to his companion Hey, he looks like he might know something about computers! And he stopped me and asked a few technical questions about Linux and about a Windows XP reinstall he was contemplating. His speech was a little slurred, but his comments made perfect sense. Huh. Something similar happened a few weeks ago when I was stopped by a gentleman smoking outside his apartment. He didn't want to ask about computers, but he did want to read my t-shirt, which had a summary of the RSA cryptosystem algorithm on it.

When I was young, I used to respond to inquiries about my day by saying We ate lunch; and we had recess... Since then, I've added a few things to my list, like I had coffee, and I attended a seminar. But if asked what I did at the end of the day, my inclination is still usually to blink owlishly and ponder for a while. If pressed, I'm likely to blunder and talk about whatever I was thinking about most recently, whether or not it had anything to do with the bulk of my day. It takes me a while to digest experiences.

I remember food, though. So far, this has been a good week for food. I spent Saturday with Winnie, and we had Zachary's pizza for lunch and black bean soup with sausage for dinner. The pizza was thin-crust, not the usual deep-crusted Zachary's pie with all the fillings on the inside. They didn't have the deep dish pizza by the slice, and I still owe Winnie a deep-dish pie at some point, but the regular slices were still good.

The rest of the activities of the afternoon were like lunch: they didn't go as planned, but they turned out well in the end. We went to Sausalito and spent some time walking around there, and planned to then walk over the Golden Gate Bridge. But we missed the turnoff at the beginning of the bridge and ended up stuck in traffic in San Francisco. This weekend was the Fleet Week celebration, and about a million people went to San Francisco to see the Blue Angels stunt flying. Consequently, we were in traffic for a long time. But we listened to Prairie Home Companion on the radio while we waited, and had a very satisfying dinner when we got back: bean soup, bread, asparagus, potatoes, and chocolate turtle brownies for dessert.

Sanjay had some of his students over for dinner on Sunday evening. The food and company were good, and the kids were cute. Dessert was a fancy-looking chocolate cheesecake, though Sanjay claims is simple to make. Whether it was simple or difficult, it was delicious. On Monday, Dave D. and I had ceviche (a Mexican fish dish) and tacos and talked about a change-of-basis problem. We finished the brownies from Saturday for dessert. And later I had tea biscuits with my tea, and ate some of the chocolate turtle candies that Esther bought.

I seem to be eating a lot of dessert recently.

Perhaps there's a correlation between more desserts and more computer failures, for surely that has been another characteristic of this week. Hardware that has thus far been quite reliable -- my laptop, for instance, and the router that Patxi and I use -- has decided this week to show its cantankerous side. My laptop usually goes for weeks at a time between reboots. So far this week, though, I have rebooted at least once a day. You'd think I was running Windows, but I'm not. I believe I know what the problem is, though. There are documented peculiarities in the video hardware on this laptop, and I've been stressing that hardware more than I usually do in the preparation of my fluids homework for this week. Perhaps I just need to upgrade the driver.

While I think I may know the issue with my laptop, I have no idea what has gotten into our wireless router. Occasionally the router just hangs; at other times, everything but the DNS redirection seems to work. Rebooting the router usually fixes the issues -- though not always -- but it's still troublesome. Perhaps I should update the firmware for the router as well as the video drivers for my laptop.

The matrix computations seminar today was made more entertaining by a hardware failure, too. The overhead projector would not project, for no reason that any of us could ascertain. So we all tested our eyesight by looking at the monitor and at the whiteboard until one of the media technicians could come to fix the problem. He did come in the middle of the hour, but eventually declared, Sorry, folks. I'm going to have to look at this later. It just doesn't seem to respond to commands. At that comment, Ioana leaned over and whispered, We could have told him that. Which is true, but probably beside the point -- I doubt he would have believed us.

I've prepared a computer presentation for the talk I'm to give Friday, but perhaps I'd better print overhead slides tomorrow as well, just for insurance. This does not seem to be a week to test the determination of whatever spirits enforce Murphy's laws. I imagine that I'll seem curmudgeonly enough by the end of my talk without any projector failures, though. My talk has three parts: an overview of resonant microstructure design; some ideas underlying eigenvalue computations; and advice about how to be a wise consumer of numerical software. I've tried to leaven the last section with humor, but I think people draw some really boneheaded conclusion from poorly conceived numerical experiments, and I expect my opinion of such shenanigans shows in the slides.

In reviewing my slides, I'm also reminded that graduate students supposedly turn into their advisors over time. I hope that I'm combining the better parts of Jim and Kahan's respective presentation styles, and not taking the worst of both and adding a few new flaws of my own. For better or worse, I can see the influences of each of them in this talk.

Usually, I drastically underestimate the time it will take me to finish a presentation. I've gotten better at recognizing my optimistic tendencies and compensating for them, but I somehow managed to finish the slides for this presentation in about the time frame I had planned. Perhaps to compensate, I spent far too much time this week on my fluids homework. The problem wasn't particularly hard, but it was fun and it generated pretty pictures, and so I spent a lot of time exploring. In essence, we were looking at the movement of fluid around two propellers, each active in turn. It's a little like the flow generated by an egg-beater; the material is pulled around the propellers, and at the same time it gets folded up, so that very quickly it becomes interestingly complicated. So I spent far too much time generating and admiring pictures of what happens when you draw an initially square grid in the fluid and then stir it up with the propellors, or of what happens when you drop a string into the flow and then let it get stretched and folded. The problem is due Friday, but I turned it in early this afternoon, purely out of defense of my productivity for the rest of the week.

Also out of defense of this week's productivity, I have decided to skip the IEEE meeting for the month, which takes place tomorrow. I really want to get some things done by the week's end, and it does not seem wise right now to take a day off to pick floating point nits. If I have some extra time during the week, I'd much rather spend it on books than on meetings. I still have not finished To Say Nothing of the Dog (Willis), and there are new books I would very much like to read some time soon: Quicksilver (Stephenson) and Paladin of Souls (Bujold). I'd also like to spend more time working my way through the technical texts I bought at the beginning of the semester. Reading and writing and thinking seem much more important right now than trying to stay awake through meetings does.

On the whole, I think I've done well recently at balancing time reading and thinking with other demands. I spent some time this afternoon hiding at a cafe in Berkeley and reading through Kahan's notes on Laguerre's iteration for finding polynomial roots. And last night I spent some time reading the most recent SIAM News issue. Of course, the thing I remember most from reading SIAM News is that there is a new edition of Allgower and Georg's classic Introduction to Numerical Continuation. Their old edition was released into the public domain some months ago, and so I returned the aging copy I'd checked out from the library and switched to the electronic version. But if there is a new edition with better typesetting and new material, perhaps I'll invest in a copy. It's a book I already use, after all.

I'm convinced. I think I'll go buy that book, now. And then I'll make some food. And perhaps take a short recess.

• Currently drinking: Green tea

There were students in the fluid mechanics course this morning, but there was no lecturer. From what I heard, it sounded like most of the class was still mumbling over the homework, and was perhaps happy for the time to confer. I spent the time talking with another CS student taking the course, a graphics guy who I've known for a while and who is interested in a lot of the same simulation issues. And then I was able to go to the office at 9:30 instead of 10:00. So while I'm disappointed that I missed the lecture, I did at least get some unexpected time out of it.

I spent the afternoon working out the slides for the talk to Anant's group. I think I have them in more-or-less final form, except for a few at the end. My talk is scheduled for this Friday now, and I'm glad it's so. I look forward to giving this talk, but I also look forward to being done with it. I have too many things on my plate right now. That's eternally true, but it makes it no less a relief to be able check tasks off.

I had an interesting conversation with Anant, Mike, and Tracy after dinner this evening. The conversation wandered back and forth across a range of topics, as conversations often do. At some point in the natural flow of topics, Tracy commented that my speech reminded her very much of a Pennsylvania Dutch colleague. I said I thought it was likely in the vowels, since that's what I notice most when I'm among relatives in Pennsylvania. She thought it was the lack of variation in my tone during normal speech.

I thought a little more about Tracy's observation later. I've been told the same thing on other occasions, but I still have not figured out why my accent should sound Pennsylvania Dutch. It's true that this is my mother's accent, and the accent of her side of the family. But it isn't my father's accent, nor the accent of where I was born (Iowa), nor the accent of Maryland, where I spent my years from middle school through the end of college. And I know there are traces of all those places in my speech. So why does the contribution of a specific Pennsylvanian subdialect stand out so?

I made fried potatoes and sour cabbage with honey and apples this evening, and Anant made daal. Surprisingly, the three dishes went together reasonably well. Tracy likes this variant of sour cabbage better than the one I often make (with garlic and pepper), while I think Mike prefers the other version. Anant didn't express a preference. I'll happily eat either.

I just found out there is such a thing as an Anger function. It's a special function related to Bessel functions. I have no idea where it is used, nor do I particularly care at the moment. I just think it's an amusing name.

I'm sure there's also a generation of students who thought it amusing to have classes with Professor Anger.

I don't have the same special dislike for Bessel functions and their kin that I think my dad acquired in college, but neither am I thrilled when they appear in homework computations. Usually by the time I'd think of using Bessel functions, though, I've given up on analytical methods and turned to the computer. And the fact that I remembered where to look for Kelvin's differential equation is dumb luck. Well, it was dumb luck insofar as there is anything lucky about looking in a standard reference. Blessings on the heads of the late Milton Abromowitz and Irene Stegun.

I spent some of Saturday evening visiting with the chemical engineering crew and eating an after-dinner dinner. We played a card matching game called Set and talked about this and that, where this was about half science and that was about half mathematics. I'm glad to have friends who find such conversations as fascinating as I do. Or at least who find them fascinating.

I went to San Jose yesterday afternoon to visit Winnie. That was a lot of fun. She's good company, and I really liked the carrot soup we had for dinner. I'd say it was better than Bessel functions, since the alliteration appeals to me, but I think that would be damning both the soup and the company with fainter praise than they deserve.

And now I'm going to make a cup of tea and switch from homework to research work. I think it would be appropriate to choose somethng that doesn't involve cylindrical harmonics.

• Soon to be drinking: Green tea

My cold was mercifully mild and short in duration. I felt well by Thursday afternoon. I'm still drinking the wild berry zinger tea, but that's just because it tastes good. And it's a hot liquid, which is nice when the days are cool, as they have been since midweek.

I bought a Scrabble board yesterday afternoon, and played a game with Mike and Anant last night. I managed to play hyssop on a triple word score, which made my day. I enjoyed playing, as I think Mike did. It seems Anant is less fond of Scrabble.

I visited amazon.com this morning to look up information on a few recently released books. It's amusing to see Amazon's recommendations. I thought the software might recommend Quicksilver, the new Stephenson book, but instead it suggested Moving Toward Stillness by Lowry and Elements of the Theory of Functions and Functional Analysis by Kolmogorov and Fomin. I suppose I can forgive the failure of Amazon's software to read my mind, since the recommendations are based on limited information and since it still manages to recommend books that I find interesting. And I do think both functional analysis and Lowry's essayson Japanese martial arts are interesting.

The recall election takes place in only a few days now. I will only listen to the news about it on the radio every once in a while, since otherwise I'm sure my eyes will roll right out of their sockets. It's a campaign of style over substance. I do not plan to vote for Schwarzenneger, but that's because I don't know his position on many issues, and because his rhetoric is ludicrous. I did not come to such a decision because I felt infuriated by the allegations of harrassment against him, nor because he might believe Hitler was an effective public speaker. After all, Hitler was persuasive; otherwise, he would not have been nearly the danger that he was. If anything, I'm irked by attack ads and quotes from people who probably doubt the accusations as much as I do.

I feel like I spent the week helping other people out more than working on my own tasks. I like to feel like I've been helpful, and I don't mind spending some time to provide assistance. But I'm glad that I have the flexibility to sometimes work from home, where it's much less likely that someone will knock on my door and interrupt my train of thought. And I'm also glad to have friends who will visit for dinner, and books to read, and other ways to take evening breaks from technical tasks -- my own and others'.

• Currently drinking: Black coffee

I have a cold, or at least a good approximation to one. I also have a cup of herbal tea with honey. The two don't cancel, unfortunately. But the tea is hot and sweet and berry-flavored, and it's gentler than a cup of coffee. My symptoms are mild -- just a stuffy nose -- and I have high hopes that they will dissipate soon. Hope springs eternal.

I've lost my Sandia National Lab mug, which saddens me terribly. I should remember to bring a replacement mug to the office. The cabinet at home is full of mugs to the point of overflowing, so taking a mug to the office would solve (or at least partially ameliorate) two problems at once.

I have a difficult time remembering how exactly my week has gone so far. There was a lot of interaction with various folks: I was a guinea pig for Raffi's user study, helped Sanjay with a presentation, talked to a classmate about the fluids homework, and sent out an example parameterized system for Jiawang to use for his experiments. I also finished the fluids problem for this week. And I intended to go to bed early Sunday night, Monday night, and Tuesday night, and failed each time.

Perhaps I'll succeed in going to bed early tonight.

• Currently drinking: Wild-Berry Zinger with a liberal dose of honey.

All bad poetry springs from genuine feeling.
-- Oscar Wilde

I'm not working hard right now. I'm listening to To the Best of Our Knowledge online, reading Oscar Wilde quotes, and sipping chamomile mint tea. It doesn't seem such a bad way to spend Sunday night.

The following recipes have seen recent use.

---

• Beef (I used about a quarter pound -- tofu would probably work, too)
• Small onion
• Mushrooms (ordinary cut)
• Garlic (2-4 cloves)
• Ginger (perhaps half as much as the garlic)
• Soy sauce
• Black bean sauce (half a spoon)
• Red bell pepper (one)
• Hot peppers (I used two serrano)
• Baby corn (half a can)
• Vegetable oil (a couple teaspoons -- I use olive oil)
• Sesame oil (maybe half a teaspoon)

Cut up the beef (or tofu) into a bowl. Dice or grate the ginger; crush and dice the garlic. Mix the ginger, garlic, and black bean sauce with the meat, then douse liberally with soy sauce. Put the bowl aside to blend for a little while.

Dice the onion, bell pepper, and hot peppers. Heat the olive oil and sesame oil in the pan, then start the onions. When it smells ready, throw everything else in -- the meat, the peppers, and the baby corn. Let it cook until it smells done.

---

• Green beans
• Peanuts
• Garlic cloves
• Soy sauce
• A little oil

Put a little oil in the pan. Dice up some garlic and throw it in, too. Cut up the green beans. Put in peanuts -- I use a 1:2 or 1:3 ratio of peanuts to green beans (by volumes). Cook on the stove on high, seasoning with soy sauce to taste.

---

• Red cabbage (half a head or a whole head)
• Plenty of vinegar (white vinegar, cider vinegar, rice vinegar, balsamic, or some combination thereof)
• Salt, pepper, and garlic to taste.

Drop everything in the pan. Heat until the red cabbage is flexible and the vinegar is bright purple with the cabbage juice. Don't skimp on the vinegar. Add salt and pepper as you cook, tasting frequently to make sure it still tastes right.

---

• Plain yogurt
• Diced fruit
• Honey
• Cinnamon

Mix honey into the yogurt to taste. I use perhaps a teaspoon of honey per half cup of yogurt, but I like the yogurt tart; the ratio also depends on the type of yogurt you use. Sprinkle cinnamon over the top, enough so that you can see distinct swirls when you stir things up. Put the yogurt over top of the fruit or mix the fruit into the yogurt, whichever way seems most appealing.

---

• Two cans of black beans
• One large can of tomatoes (use fresh tomatoes in season)
• One large onion
• Garlic (2-4 cloves)
• Salt
• Lime juice (or a lime)
• Cumin
• Chili powder
• Hot peppers to taste

Saute the onion and garlic. Add the black beans and tomatoes and squirt in a generous amount of lime juice, or just cut a lime in quarters, squeeze the majority of the juice over the beans, and then toss what remains of the fruit into the pot. Sprinkle the top of the mix with equal parts cumin and chili powder, enough to get a film over the top of the entire pot. Add salt to taste. Throw in a bay leaf or two if you fancy it, simmer until your hungry or you're finished with other dishes, and eat. Goes great with rice. You might want to fish out the limes before you eat, though.

---

All recipes go well with a half cup of adaptation before and a cup of tea after.

• Currently drinking: Chamomile and mint

Autumn is here.

Autumn in this part of the SF Bay area is not so dramatically different from the rest of the dry season. The days are shorter, and some of the deciduous trees are just beginning to think about losing leaves. This morning it cool and grey and quiet, and there is enough moisture in the air that the edges of Albany Hill appear monochrome, and just slightly flattened and blurred, as they might in a charcoal drawing. Even here, though, there are autumn days when the clouds roll out, the sky is a bright, clear blue, and the air smells of cool days and turning leaves.

Patxi received bike tires by UPS this week, and both Esther and I were here Friday afternoon to ensure that Patxi wouldn't have to go to Richmond to pick up his package in person. We were both working in the living room when Esther asked, Bindel, are you feeling homesick? I thought for a second, and replied A little. I wasn't really sure why, then, but it sounded right. I think, perhaps, I miss fall in the woods most of all right now.

On Tuesday or Wednesday afternoon, I took a break and had a cup of coffee with Christof at Brewed Awakening. There was a breeze, and bits of fallen leaves kept showering onto the heads of passers by. Christof commented that it was like rain, and I replied that perhaps this is why the season is called fall. Then we went back to the office to work.

Yesterday morning, I finished Children of God (the sequel to The Sparrow) by Mary Doria Russell. I highly recommend both books. Yesterday in the early afternoon, I finished my PDE homework for the week, and in the late afternon and evening I spent time with Winnie.

Today, I think, is reserved for polynomial computations, fluid mechanics, talking to Patxi about numerical solutions of ODEs, and perhaps taking a walk in the sun.

I'm drinking Stash peach-flavored black tea again this evening. It suits me particularly well this evening.

Sanjay and I met at a cafe at 9:00 this morning to talk about where we were and what we wanted to ask Howe and his students when we met them at 10:00. The meeting with the resonator folks was productive, I think. After the meeting I had a short break, then PDE lecture. Then I spent some time quietly scribbling my way through some more scrap paper, and then came home. I bought some groceries on the way back: milk and cereal, pears and yogurt, cabbage and baby corn, and black bean sauce and chow mein noodles. Huzzah for food! And for someone to help eat it.

I think I should turn in early tonight. When I'm tired, my eyelid betrays me. In fact, it betrays me whether or not I actually realize I'm tired. It started to droop markedly shortly after I returned home. My eyes have been particularly irritated since yesterday morning, or perhaps even since late Sunday night; all the more reason to let them close early.

• Currently drinking: Black tea with peach

I re-registered to vote, got my student bus pass for the semester, and fixed my 1D thermoelastic code for today. I did a few other things, but not so many that I was impressed with myself. I worked some this evening, but I also took some time to visit Trader Joe's to buy ginger cookies, tea, and rolls for lunch for a few days.

I'm digesting a lot of things right now. Part of the process of doing that digestion is to spend a lot of time staring into space. Sometimes I look like I'm daydreaming; sometimes I daydream in truth. But for me, time spent staring at a wall is as vital as time spent staring at papers and code, or as time spent scribbling page after page of scribbled equations and interspersed with question mark. I know this is true, yet I still find it frustrating not to be able to point to something concrete at the end of the week and say There! I have worked well, and that's the evidence.

Think, think, think, as a certain stuffed bear was wont to say.

I remember talking to Kahan once about his days as a graduate student. He said there was a courtyard where people would walk and think. No e-mail or phone calls, just time to think. And that, he concluded, is a problem for students now: where is the time to think? I'm not sure I believe there was such an idyllic time, though I wasn't there to witness either way. Online time has its own stresses, but the computer also simplifies tasks, both as an assistant to computation and as an aid to data management and communication. The only trick is the ability to walk away from the computer, perhaps to scribble on a pad, perhaps to stare into space over a cup of tea.

I spent yesterday neither staring into space nor staring at a computer. Instead, I spent the afternoon and early evening wandering about San Francisco with Winnie. She's good company, lively and funny. We walked from the Powell Street BART station through Chinatown to the north edge, then turned at Pier 39 and walked west along the coast to the Palace of Fine Arts. Then we walked back along the coast, with a break for ice cream at Ghiradelli's square. Then we took the trolley to near where she parked. She drove me to my place, and I made tea; but since it was late and neither of us were all that hungry, we decided to save dinner for another day.

It was a day of no math, unless you count the conversation about the chimney decoration that reminded me of an integral sign. I thought that someone might make an action show starring me, in which the transitions were marked by a spinning integral sign zooming into the screen and then zooming back out, as the old Batman episodes had transitions with a bat spinning in and out. Winnie thought it might make also make a good hood ornament. And I did only a little work at the computer, and that in the morning. I did no computer work, either, except in the morning. But we walked and talked and enjoyed the day, and that's important, too.

Tomorrow morning, I meet with people to talk about simulating damping mechanisms in resonators. And that will be fun, too.

• Currently drinking: Black tea with peach

Once a month, I travel with W. Kahan and Jason Riedy to some location in the South Bay for the meeting of the IEEE 754 floating point arithmetic standard revision committee. It is a monthly lesson in arithmetic, computing history, and perhaps a bit of cultural anthropology. It's also a test of endurance and a penance, though I'm not sure for what it is a penance. We have dinner afterward, though, and this month was no exception. So if it's a penance, it's an imperfect one.

The IEEE meeting is not a red herring, a lame duck, or a shaggy dog. More's the pity.

I intended to do a little more work this evening after returning home, checking some equations, and writing my solutions to some homework for tomorrow. I've now returned home and finished with the problem set and the equations, and decided that there is little essaying any more for the day. I'll make a cup of red tea and end on a high note.

• Currently drinking: Cold water

I left the house late this morning expecting that I would miss the delivery of the last part of my book order. When I returned, though, there was no sticker on my door to say that UPS tried to deliver while I was out. I'm not sure whether to be glad, because I didn't miss the delivery after all; or impatient, because I want the book to come soon. I think I'll settle for glad.

I finished the proof of a theorem that I conjectured was true nearly three weeks ago. Ultimately, the proof was short and simple, but I'm more inclined to pat myself on the back for finally finding it than to chastise myself for not finding it sooner. Still, I expect this result to be useful in my evaluation of a source of (mercifully rare) error growth in the structured eigenvalue solver I've looked at for the past few months. Yesterday, I did some calculations based on the sensitivity of the coefficients of a polynomial to perturbations in the roots. Tomorrow, perhaps, I will spend some time actually devising test code based on these results.

Actually, I expect I will spend much of tomorrow wearing my mechanics hat. There is a homework set due on Friday in my fluids class, and with the IEEE meeting on Thursday, I expect little time to finish the homework after tomorrow, and I'm a little confused by it right now. I hope that I'll find out in office hours tomorrow that I'm confused on something simple and that the problem is, in fact, as simple as it sounds like it ought to be. I'm also supposed to meet with Sanjay tomorrow afternoon to compare notes on our respective numerical solutions of a simple 1D thermoelastic damping problem. I'd like to review my code before we meet, since he mentioned that the solution has a boundary layer that I may not have resolved. I don't expect that any refinements I make will substantially change my results, but I should still check.

I worked from home and from a local coffee shop for most of today. I was in the office just long enough to have a conversation with Kahan regarding evaluation of accuracy for polynomial root finders. Then I went to the cafe and sat with my cookie and coffee and pad of paper for a while to think thoughtful thoughts. Anant came by a little later, and we had an interesting conversation. Conversations with Anant are always interesting; he works on nuclear magnetic resonance and I work on numerical computations and linear algebra (and other odds and ends), but we both have at least a little understanding what the other does, and we both like to explain what we're working on to anyone who looks even remotely interested. So I tell him about eigenvalue problems and he tells me about nuclear spins and we both walk away happy and a little more informed about the world.

My days have been full and interesting recently. It keeps me happy, but it's exhausting, too.

• Currently drinking: Red tea