Donald Knuth and MathOverflow

January 15th, 2010 § 0 comments § permalink

Yesterday evening, I arrived early for a dinner with a bunch of mathemagicians from the Joint Mathematics Meeting. At first glance, I didn’t recognize anyone in the restaurant lobby, and when I asked the hostess she confirmed that my party had not arrived.

On second glance, I did recognize someone in the lobby. His face was iconic, but it was his name tag that confirmed it beyond a doubt. I felt immediately nervous and to suppress it, I walked up immediately and introduced myself, “Are you here for the MathOverflow dinner?”

And Don Knuth responded, “Yes, I read about it on the site, but it seems like I’m the only one here. I wonder whether this is really happening.”

I said I’d check in with my friend Anton who organized the meetup, pulled out my cellphone and typed an SMS.

“What’s that?” he said, and pointed at my phone.

I was a little puzzled, but I answered the question at face value, showed him the iPhone, the touch interface, and the chat application, all of which seemed to amuse him.

“Maybe I’ll get one of those when I am ready to communicate again.” He told me that, in the meanwhile, he was still keeping himself free of distractions while writing. “Maybe, when it‘s done, in say 20 years… Though by then,” he mused, “the gadgets may get so complicated that I would never be able to figure it out.”

“Yeah, this one here,” referring to my iPhone, “is just the gateway model to the future.”

***

Our group size was intimate enough that we could huddle around Donald Knuth as he shared stories, one of which I paraphrase from his perspective:

Given that my life is so intertwined with algorithms, there was a time that I became fascinated with the idea of making a pilgrimage to the birthplace of Algoritmi (Latin form of the person from whom the word etymologically stems).

When I looked it up on the map, I was disheartened at the fact that it was in the Soviet Union, near the town of Khiva/Urgench in Uzbekistan. I’m never going to get there, I thought. It was the 1970s.

I mentioned this fantasy offhand to a colleague from the Russian Academy of Sciences. And two years later, he called me up to invited me on an official government visit to an Algorithms Meeting in Khiva.

So, not only did I get to go on my pilgrimage, but a hundred girls with flowers greeted us on the tarmac!

There were some visa problems, so the French mathematicians couldn’t make it. It was a nice meeting. We dedicated a town square for the erection of a statue to Al-Khwārizmī and I recently confirmed with Google Earth that the statue is in fact there.

from http://books.google.com/books?id=3Sfrxde0CXIC&pg=PA31&lpg=PA31&dq=khiva+statue+to+Al-Khw%C4%81rizm%C4%AB&source=bl&ots=l3G8Bozwsq&sig=jNfAVtOE8OD5nQU-0bBTr1OksCo&hl=en&ei=dXAhTNvjAYvqnQfpgJF0&sa=X&oi=book_result&ct=result&resnum=5&ved=0CCoQ6AEwBA#v=onepage&q&f=false

***

He mentioned his 72nd birthday last Sunday, so in secret we ordered him a little cake and sang happy birthday!

from http://www-cs-staff.stanford.edu/~uno/news.html

Where the Buttocks end & the Hemotomas begin?

January 13th, 2010 § 4 comments § permalink

… or My Sunday Skiing Accident

It seems like everything I write is an accident report, and I’m not even an emergency professional. Hopefully this is my last one. I am retiring from accidents, and the following is the beginning of an exploration of how.

I’ve got two very large hematomas on my rear end. (On top of never being able to sit still) I will not be able to sit comfortably for at least a few days, and since I am on pain killers my mental game is almost completely shot.

It could have been a lot worse.

Skiing this Sunday, I went up a ramp for a jump. It was my first time on that run, and I had no idea what was on the other side. My mental model was a flat elevated bank. I don’t know why. At the moment I got airborne, I realized just how wrong I was.

The Fall

Given the abrupt drop, I don’t think I could have landed anyways — not that a better skier wouldn’t have been able to handle it. The fact that my trajectory invariably resolved to a large rock bulging out of the mountain, made landing the least of my concerns.

fuzzy sketch. ~15ft from take off to landing.

When we were going up the ski lift, Mike told me of a cliff on this mountain that he almost accidentally skied off the previous year. “I almost died right there,” and pointed at it.

I thought about this as I cradled myself for the fall and in a short time which seemed like eternity, I came to terms with all of it — the blood and the snow, the bone and the rock, and sinew — for what use is there in protesting the inevitable?

not the slope i fell on. it's from my previous run. here to convey the terrain.

But I did protest (on behalf of my whole-ness) as best I could: I crouched; I lifted my hands to my head and let the ski poles stick out over my elbows forming a kind of cavity; I tried to take the first impact on my skis, which I managed, bending my knees to absorb; the second impact on the poles, and then I lost control. The skiis and poles went flying, my rear end significantly clipped the rock and I tumbled past it down the hill, futilely trying to account for my limbs and slow the slide.

When I came to, I didn’t know which side was up. I was both stiff and shaking and the only word that came out of my mouth was “fuck”. It came out loud, “FUUUUCK”. It came out in short sequences, “fuck, fuck, fuck”. And it came out with every breath until I managed to roll myself on my back and lose myself in the cold embrace of the snow. I didn’t see any blood and surprisingly, I could still move my fingers and toes.

Mike, who had been snowboarding behind me, watched me ascend and fall out of view. He appeared at the crest. A couple of boarders who witnessed my inglorious moment told him, “your boy ate it real bad, and probably needs the ski patrol.” Besides the fact that one of my skis skied on without me, there was no way I could make it down the mountain myself.

Damage

The ski patrol came, wrapped me in a stretcher and towed me with a snowmobile to the medical clinic at the base. They made sure I didn’t have any bone or spine damage and let me out of the bindings. When I reached around to palpitate my behind, I felt an unfamiliar bulge and another.

I asked to go to the bathroom, where I turned my back to the mirror and took off my pants. It looked like a pomegranate was glued to my left buttocks and an eggplant was attached to my right thigh. I estimated that a pint of blood filled each shape. My skin was stretched taught and reddish purple. Nothing else looked as bad or hurt as much as those two places.

It was then that I realized that my ass was so big, that I could not get my pants back on. Nor could I bend over sufficiently to take off my skiing boots. I walked out into the hallway in boxers with my pants dangling at my feet.

The doctor helped me with the boots and said these were among the worst hemotomas he has seen and they would likely need to be drained in a few days. He gave me a few Vicadin on the spot and a prescription for more, “you are going to need this.”

Hematoma

For the next 48 hours, I stuffed loose fitting pants with ziplock bags of snow or ice. I attached them with binder clips at my waistline to keep them properly positioned. I slept on my stomach with my rear elevated and iced. As I sit writing this, I’ve folded pillows into complimentary shapes. I’ve been using an ergonomic chair that shifts my weight to the knees. When I go to the bathroom, I dream about a squat toilet. (I record this because it’s important not to forget these pathetic nuances of dealing with basic necessities, to relate to the realities of old and infirm.)

i have reduced this image and obfuscated it to keep it appropriate.

Over the past three days, I’ve taken up valuable time from various people: Mike, the ski patrol, the mountain med clinic, the student health clinic, the ER. My department and graduate advisor have helped with health insurance, (an issue now that I have graduated.) I’m lucky to have this network of support. And I’ve been told by almost each of them of how lucky I was to have gotten off with the damage I have, from the impact I had. And the problem is that I have put myself and such people through this charade already several times.

Lessons

So what’s the lesson here? Obviously, don’t jump without knowing where you are landing. Prepare for tricks by first studying a given run several times. Wear a freaking helmet.

But for me, the lesson is different. I get into these situations too often. If I learn that discrete lesson, new lessons will remain to be learned. And besides, mountains sports are inherently dangerous. The medical clinic was full to the last bed, like an inner city trauma ward, and some of the sights weren’t so pretty. Last time I went snowboarding, I fractured a rib and it hurt to breathe or sleep for almost a month.

So, I have decided to retire from mountain sports. Skiing/boarding is fun. It’s just not for me. I like challenging myself, which would be fine on a basketball or volleyball court, running or playing squash (though I get injured there too). An alternative would be to reflect and consider some behavioral remediation and generally tune down my avarice for risk. But since I actually treasure that aspect of my character, I am choosing to instead restrict the domain of activities I engage in, to those with better exercise/fun/reward vs risk trade offs.

Sore, but happy to have this off my chest, ./pp


Here are some photos of the progress:

Left Buttocks 1

Right Thigh 1

Left Buttocks 2

Right Thigh 2