My Postdoc Time in Paris

This is a summary of my first impressions of Paris, when I worked at the INRIA Saclay as a postdoc in 2010.

This text is a purely personal collection of impressions, published here with the sole purpose of entertainment. By reading this text, you agree that I will not accept any responsibility for correctness or completeness or politeness.


Public soccer viewing
Yes, I admit it: The fact that the job was in Paris was a crucial factor when I decided where to go. And I do not regret it :-) Paris is as vibrant a place as you imagine it: White faces, black faces, yellow faces and recently, during the World Championship, also blue-white faces, green faces and black-red-yellow faces. Be it the countless cafés that line the streets, the little churches dotted all over the city, or the majestic edifices in the parks — I just cannot help noticing a subtle difference to my previous homes, Saarbrücken and Mountain View. The Louvre, the Eiffeltower, Notre Dame, the Champs Elysées, the Arc de Triomphe, basically all the stuff that sounds cool, and that you did not know how to pronounce when you read it or to write when you heard it, is in Paris.

The Institute of France
Every quartier has its grandiose building: the Panthéon (they have a copy in Rome, though), the Assemblée Nationale, the École Militaire or the Palais du Luxembourg. Most other buildings are, as Wikipedia puts it, neo-classical stone buildings of bourgeoisie standing. For those like me who did not know what this means: It is the type of buildings that look simply nice, see pics. Most impressive, though, is the sheer density of people. People are everywhere and always, dining in the ubiquitous restaurants, pushing through the streets, squeezing themselves into subways, queuing at the supermarket, clustering at tourist attractions, or paving over the pedestrian bridges with picnic gatherings. This is in sharp contrast to my previous place, Mountain View in the US, where everything was basically vast and empty. You could walk for hours without finding a restaurant. Here, you have to walk for hours if you want to find a spot without one. I remember my Singaporean friend in Mountain View, who always told me how much he cherished the vast spaces in the US. This is
A book shop
understandable when you come from a place like Singapore, with a population density of 3 people per cubic metre. For a person like me who is from a rather small town, however, the liveliness of Paris is just awesome. There is music everywhere (yes, that accordeon tune that sounds like in the Amélie movie) and you can eat crêpes everywhere. Different from what their name suggests when pronounced in English, these fine pancakes are just delicious. I believe France has the highest Nutella consumption per capita; it is the main ingredient in most crêpe recipies.

Traffic in Paris is chaotic, to put it mildly. Busses, cars, bicycles and pedestrians mix liberally and traffic lights serve mainly for illumination. Following the idea of a popular search engine, I have the goal of traversing the whole city by foot. I have done the southern part of the city so far and the northern part will eventually follow. This plan is facilitated by the good infrastructure that Paris provides. Tramways, subways, trains and busses go every few minutes and roughly connect every spot in the city to every other spot with at most one change of transportation device. The infrastructure is not restricted to transportation: Every few hundred meters there is a public park for taking a break — often with a fountain with drinking water. Paris also sports 400 public toilets, which are free of charge (with the obvious, well-meaning intention). After usage, the toilet seat and the floor is flushed with water, desinfected and dried. For a small surcharge, or if the system determines the necessity, this process is also applied to the user (just kidding). Paris even has a public bicycle system, where bicycles can be checked out at special bike stations, and checked back in at any other one. (The number of the bikes that is present at any given station also serves as a good indicator for the attractiveness of the place.) Bicycle stations, subway stations and toilets are always equipped with a map of the local area, which is perfect for a map-oriented person like me. During my journey, I am swimming in the stream of people, adopting local customs and disguising myself in the anonymity of the city. I assimilate so well that I bet that no local person could tell that I am not what I seem to be (a tourist).

My place

When I step in
The coolness of Paris comes at a price, though. This price is either in Euros that you pay for your appartment or in space that your appartment lacks. My case is the latter. I am living in a small room that barely deserves the name (I refer to it tenderly as "the wardrobe"). I was told that it measures 15 square meters, but this is only if you count the floor, the walls and the ceiling. The place is under the roof and has a slope. The part where I can stand is 5 square meters (53 sq ft) — 1 square meter of which is the shower. Yes, the shower is built-in and when you step into the room, you are basically in the shower. The "bed" (French for "matrass") is under the slope. All my activities are ordered by height: Sleep in the area where the roof touches the floor, sit in the area where the roof is at head height, shower in the area where I can stand and live in the area where I can move freely (i.e. outside my place). The advantage of being under the roof is that it never gets cold in summer. Even when the outside temperature drops to a freezing 25° Celsius (77 Fahrenheit), the inside maintains a pleasant 37 ° Celsius (100 Fahrenheit). The place is also quite noisy, with a busy street right next to the building. A nearby church calls me every Sunday with bell ringing (but without success so far). New investment into a fridge and a fan, the reparation of the shower curtain, a new carpet, a visit to a major Swedish furniture shop and some general clean-up have improved the quality of the cubbyhole, though.

When I step out
The advantage of the place (and the reason why I am still here) is that it is right in the center of Paris: At Saint Germain des Prés. Right when I step out of the building, I am at a cute square with little cafés and a church that dates from the 12th century (for US-born readers: This is before World War 2). If I do 2 more steps, I am at the entrance of the Metro, the Parisian subway system. If I do even more steps, I am in one of Paris' most lively areas, the Quartier Latin. Here, you can eat breakfast, lunch and dinner in any order at any time of the day or of the night. If I do the steps in the other direction, I am at the river Seine. Notre Dame is just 30 minutes away from my place (10 minutes if you walk instead of driving). And yes, I am having crêpe every day.

The Economist says that Paris is the world's most expensive city to live in. Consequently, even my wardrobe is twice as expensive as my place in Saarbrücken was (which had a kitchen and a balcony... sigh...). But then, on the other hand, Paris is also at least twice as cool as Saarbrücken. And, as my Italian friend noted, the thing that makes Paris so attractive is that Saarbrücken is only 2 hours away.

My work

Boarding a train during rush hours
(The people on the platform are those that did not get in. Those on the floor are those that gave up.)
Yes, I also work here. I am at the INRIA (Institut National de la Recherche en Informatique et Automation). This is a French public research institute that is comparable to the Max Planck Institutes in Germany, just that INRIA institutes are for computer science only. INRIA has 8 institutes all over France, two of which are in the greater Paris region. Mine is the INRIA Saclay, located in a small city called Orsay in the South of Paris. This means that I am spending 1 hour every day to get there — and even longer to get back. This asymmetry is due to the fact that the Parisian suburban transit system has the form of a star centered in Paris (basically everything in France has the shape of a star centered in Paris). When the trains go back to Paris, they jam in from all directions, thus delaying each other. Fortunately, the times when I usually get up are way outside the rush hours, so that I can find a place to sit and work while I am in the subway.

I do not go to Orsay every day. The INRIA institute is well linked to other research places, notably the École Nationale Supérieure de Cachan and the École Nationale Supérieure des Télécommunications — both of them "grandes écoles". With kind generosity, my colleagues have equipped me with access cards, keys and cafeteria cards for all three places, so that I now own 7 (in words: seven) cards and keys, opening doors at whatever place I might be. Even though my office is in Orsay, I spend much of my time at the other institutes, finding kind welcome and asylum in the offices of the people with whom I work (I admit I have a preference for those that have air conditioning). Speaking of the people: My colleagues are mostly students, post-docs and young professors — much like at the Max Planck Institute in Saarbrücken. People come from all over the world, with Italians, Spaniards, Russians, Americans, Maghrebians, Indians, one guy from Nepal, the usual over-representation of Greeks that seems to be built-in into database research groups, and, lest I forget, French. Languages spoken are mostly French and English, while I do my best to try the other languages whenever I happen to know them.

My boss is Serge Abiteboul. He is the most cited French computer scientist and the most cited European database scientist. Wherever I go and mention his name, jaws drop. He has proven that polynomial time is equal to PSPACE if and only if fixed point logic is the same as partial fixed point logic. (I hope I will some day be able to understand what that means.) The poor man's proof of his popularity is that he has written several influential books in computer science (which means a lot, because computer scientists are not very book-oriented) and that he has an article about him on Wikipedia. (The latter means, interestingly, that he is also in my own semantic database, YAGO.) In whatever meeting he is, he has always something smart to say or something witty to ask.

One of the aspects that made the choice for INRIA so attractive (apart from the fact that it is located in Paris) was that I have near complete freedom to work on whatever I find exciting ("comme un grand", as they said when they made the offer). Currently, I am working on merging ontologies. It is basically about figuring out whether two things are the same. This work is partially inspired by an episode of my recent life: While I was in the United States, I tried to sell something on Ebay. Ebay blocked my account, because they believed that some American guy had hacked into my (German) account. Yet, I was still myself, even if I was in America. At the end of my research project, I will hopefully have a formal proof for that. I will also see whether it still holds when I have to leave Paris one day :-)