Le Livre des Huîtres

Some pearls from a year in Paris. Advice and Requests most welcome.

Month: October, 2012

Would you read this?

Dear Readers,

I know you are all secretly following along with the hope of learning more history of mathematics. Over the past few weeks I have been researching and writing an article sized object that may one day be part of the Dissertation. At about the halfway (wishful thinking) point, I find myself floundering for structure. So here is an abstract draft, with that in mind. Specific suggestions are of course appreciated–but do bear in mind there are certain constraints on how much of a popularization (vulgarisation, as they say here) this could be. And never mind the grammar or the use of strange tenses…

Even if you aren’t interested in this sort of nonsense, you can surely appreciate the beautiful diagrams of Poncelet’s Traité, non? I very much appreciate the design of this book, where you can unfold the diagram in the back so it can be viewed simultaneously with whatever page you are reading. Unfortunately, the people who make copies for Google books did not bother to properly unfold the paper.

And speaking of my discipline in the real world, I had a really painful conversation last night about someone who thought Descartes had postulated values for x-cubed plus y-cubed is z-cubed for three positive integer values and the enormous numbers satisfying this equation had only been discovered recently using supercomputers. Well, in fact, it was Fermat who had postulated the impossibility of such integer values for any power greater than 2 (so cubed, or to the fourth, or to the fifth, etc), which had been proved correct by supercomputers in 1994.  It’s impossible, I repeated, and slowly the significance of the “it” began to change.


Abstract: In the early nineteenth century like in ancient Greece, geometry was the study of relationships between abstract figures in the plane and in space. Below this superficial continuity, geometers in France and Germany invented and promoted a variety of different means, systematized as “methods”, with which to approach old and new problems and theorems.  To better understand the set of techniques associated with proposed methods in geometry, this paper considers a set of problems that served as a battleground for methodological shows of power. A good method would lead to simplicity, elegance, fruitfulness, or generality. We will explore problems rather than theorems. Up through the nineteenth century, problems concerned constructing objects meeting specified constraints. In the context of geometry, solutions to problems were instructions to graphically render such objects, usually with a compass and straightedge, or some other set of specified tools. To verify that this solution will always work, the construction should be proved by referring back to earlier problems, theorems, definitions, and the like. The proof can employ a wide range of methods, but the solution must be theoretically realizable in geometric space. Consequently, the same construction might be proved in widely different manners, and constructions can even remain unproved–although this is generally frowned upon. Although the most famous problems of the nineteenth century (the problems of Apollonius and Malfatti, which were each solved over 100 times) will be discussed, the primary investigation focuses on a broader range of research with a narrower set of participants. The problems of inscribing or circumscribing a second order curve (conic sections: circle, ellipse, hyperbola, parabola) to a given polygon through given points or tangent to given lines can be as seemingly simple as putting a triangle in a circle. The problem generalizes along three primary paths: the number of sides of the polygon, the number of dimensions of the figures or the types of surfaces considered, and the variety of curves. We will encounter all three variations and see how approaches that might excel along one path were grossly inadequate in another. We open with Brianchon, who happily promoted a variety of methods through his career and is best known for proving a theorem about hexagons which became a very powerful tool in later applications. Then, we will meet Gergonne, an outspoken supporter of analytic geometry as well as the editor of the Annales de mathématiques pures et appliquées in which many geometrical problems were posed and solved. Within the pages of this journal, we will also be introduced to Poncelet, who redesigned pure geometry to achieve the generality of analysis. On the side advocating pure geometry as it once was, stand Durrande and Steiner, at least when it’s convenient. Finally, Plücker eliminated elimination from analytic geometry, enabling a form of coordinate representation free from tedious computations. This problem is rooted in antiquity and variations appear in contemporary textbooks, but we will primarily focus on the twenty-one year span of Gergonne’s Annales (1810–1831), the forum in which much of this debate took place.

Signs of life

These, I hope, need no introduction.

Bonne anniversaire M. J. L.

Somewhere, in a warmer part of the world, it is still my father’s birthday.

So this isn’t exactly late.

If I were better organized and had an “in” with postal immigration, my father’s birthday meal might have begun with a very special gesture from his daughter abroad.

In case you’re wondering, that’s a goose. And I’m talking about its well fed liver, which is now an illegal commodity in California. You can get a can of it in any corner store in Paris–though I wouldn’t speak to the quality.

I haven’t read the foie gras law, and I wonder about the technicalities. The basic statement outlaws the “force feed[ing of] a bird for the purpose of enlarging the bird’s liver beyond normal size.” How fat must a goose be to disqualify? Could you legally eat the breast of an unusually plump specimen? What constitutes force? I imagine that some birds are just really really hungry.

Some part of me, the part that likes to watch Boardwalk Empire, wants the foie gras law to spark some sort of prohibition-esque mafia action.

“I can get ya some fat liver, but it’s gonna cost ya.”

Time is running out on my midnight PST deadline. In conclusion, while I will set to work on my master plan to have force fed birds voluntarily fly to California, for now I can only offer some Foi Gras, a new and completely noncriminal expression which will be henceforth defined as ample good wishes for the birthday year.

Things you learn in the toilet

I must confess that ever since I saw this trashy sign, I wanted to take a picture of it and put it on my blog.

First, if we assume that signs exist to prevent things from happening again (rather than preemptively), then I find great amusement at the people who have thrown out wine bottles and sandwiches in the bathroom garbage.

Second, sanitary towels sound pretty uncomfortable.

Third, what are the unique design features of a feminine hygiene product receptacle? Well, I checked their website and allegedly this Sanitact bin should release an odor of citrus. I imagine they could say it releases an odor of the most wonderful fragrance known to mankind, because who really is going to put their head in the garbage and take a whiff to check? Ick. Or as the French might say, Pouah!

Les recettes

My sister keeps months of receipts in her wallet.

This goes to show that she does not buy groceries  in France. Unless, she has a very very very big wallet.

Given the size of my wallet and the extent of my food purchases, I choose to keep my receipts in a different place (the garbage).

While I am not buying more in France, my receipt intake has quadrupled. This is due to a lack of comprehensive inexpensive grocery stores like TJ’s or WF’s where I might make all my purchases for the week (and they might even ask whether or not I want a receipt) as well as the cash registers at the produce markets. I am not accustomed to counting pennies so often. In previous places I have lived, an apple purchase worth exactly $3.07 would be rounded down (California or New York) or rounded up (Vancouver) to something ending in 5 or 0. Here, everyone stays honest and small coins enjoy a wide circulation.

I imagine the market stall receipts are primarily for the accounts of the vendors to calculate the days earnings. Although now that I pause to think about it, considering the vast amount of paperwork required to do anything here I wouldn’t be surprised if more than a few people kept a dossier of their fruit and vegetable expenditures. I haven’t yet reached that level of insanity, but I was very grateful to have documentation yesterday when I realized that what I had thought was a rather expensive 200 grams of spinach and mushrooms, turned out to be a mistaken charge of “cresson.” I do love watercress, and maybe should have picked some up. Instead, I returned to the vendor, waited patiently in line again, and managed to communicate (“J’ai acheté seulement les epinards et les champignons.”) enough to be refunded my 2.25 (enough to buy a used book or two baguettes–not enough for a cup of coffee or tea IF you want to sit down). Not only did one receipt come in handy that morning, but I actually pined for another one after a delightful purchase at my new favorite store on earth where I bought two different kinds of dried beans and immediately forgot their names. A bit of internet browsing revealed the one as Haricots de Chevrier, but I am stumped as to the other. Any ideas for a white bean beginning with “Ploj” (that’s what’s written on the bag)?

17h shadow

There is a certain time of day when it is after afternoon and not yet evening.

When one doesn’t know whether to say bonjour or bonsoir. When the hour is too late to drink tea (or risk being up all night),

but too early to drink wine (or risk being asleep before dinner).

It’s really terrible, I don’t know what to do with myself.

Otherwise, it is not so much a drinking problem, as a drinking solution. From mugs to glasses, or I might just use my universal yogurt jar for both…

But tea and wine are not the same thing

and one really shouldn’t confuse the two.

I have tea figured out for myself. Something strong and simple, bitter on its own and just right with a splash of milk (au point du lait). No sugar, but I wouldn’t say no to something sweet on the side.

I’ve also paid a couple visits to the well dressed gentlemen of Mariage Frères to supply an afternoon genmaicha and an evening rooibos.

Wine, however, remains a perplexing mystery.

I know enough to stay clear of the under 5 euro big names, but in the realm of minor varieties I am picking at absolute random.

In Brooklyn I enjoyed perusing the wine shops with helpful descriptor cards, but I am not sure what reaction I would get at the neighborhood caviste when I ask for the best cheap wine they have. Or tell them my weekly dinner schedule–what wine goes well with peanuts and carrot sticks? So I’ve been sticking to the supermarkets where every last bottle says it best accompanies fromage and viands.

To be perfectly frank, I may not even be able to tell the difference between a very nice bottle and a passable one.
Which makes my classy wine club membership un peu ironique, non?



Il n’est pas très grand

Of late, I have decided to be a bit more adventurous at the grocery store.

Before you start to worry, I haven’t tried “la cervelle” or “les animelles.” But for more on that…

My adventure is of the tamer variety. Like buying 200 grams of les petit epeautre, without knowing what was small and going into my dinner. After a somewhat insane search for a particular yogurt last week, this week I made do with the current grocery store’s offerings.  As usual, I was looking for full fat plain yogurt in the largest container available (or in a very nifty jar if that was an option). When such a thing did not appear to exist, I tried something new.

Even if it came in a somewhat beat up package. Actually, the decomposability was another selling point.

I had heard that Petit Suisse was a real treat, but what convinced me was the advertised 40% milkfat. I am under the probably dangerous delusion that animal fat is very very good for me and I must consume it on a regular basis–case in point, that night’s meal was duck confit.

And look at that remarkable portion control. It’s not called “small” for nothing. The Swiss part, however, is a bit of a misnomer since it’s from Normandy.

I am also following dentist recommendations to replenish my calcium after a meal. Probably dribbling maple syrup on top was not part of the original intention, but it’s much much better that way.

Another small thing.

Mon travail

“How do you make a living?”

Well, my dears, I happen to be very fortunate this year in earning a Research Assistantship with no research obligations (yet) other than mine own.

When not looking at a computer screen or an old book (ah, old books…), this means this:

With respect to the history of mathematics, look who has a school named after her:

I could pretend to know a great deal about Sophie Germain, but I only have bits of anecdotal evidence. She worked in number theory and communicated under a pseudonym with Herr Gauss, who reputedly did not mind a bit when he learned the gender of his correspondent. Turns out being named after “wisdom” is a good start for a female’s mathematical career. Probably the best known female mathematician of the nineteenth century is Sofia Kovalevskaya and there was a Sophie in my office at Simon Fraser. Sophus Lie (though not a woman) was also a mathematician after which Lie groups were named.

Now back to scattering and photographing papers, err, I mean, back to work.

Musée de la chasse et de la nature

Have you seen my recent id photos?

They look pretty much like this:

I think the message that I’m trying to convey is, please, please don’t throw me out of your country. So far it seems to be working.

This is also the face I had on today while at the Musée de la chasse et de la nature. It’s only two blocks away and free the first Sunday of the month. Rather than wait in line at the also free Louvre and Musée d’Orsay, this seemed like a worthwhile alternative.

Since the museum was free, I walked right in and found myself face to face with a polar bear. Well, more like face to torso since it was rearing on its hind-legs and I’m not that tall. Can’t be sure whether the shivers that persisted for the remainder of my visit were due to the fairly drafty old building or the scores of glassy eyes looking out at me. Aside from a diverse array of taxidermy, there were also classical paintings, fancy guns, drawers of comics, contemporary  multimedia pieces, and cast models of various animal droppings.

A très bizarre, but highly recommended experience.

Ce matin

This morning I misinterpreted my acronyms and went to IHP instead of IHPST. Consequently, I missed the PhilMath conference and found myself on the left bank without morning plans.

Luckily I was armed with a camera. Here is what I saw.

What is wrong with this picture? Well, aside from the fact that the pizza looks disgusting, there is some really bizarre perspective going on here. Look at that missing slice–I can’t figure out what they’re trying to do.

This is for Popz…how did we miss this guy? There he was sitting outside of the Place Painlevé, facing toward the cinema. Maybe he was watching out for us. Shiny shoes!

Watch out in November!