SummerJob10'

Nejlepší výlety jsou výlety do pohádky, jako ten poslední.
Autobusy nás odvezly z Prahy kamsi na západ, kde jsem to předtím vůbec neznal a ta místa se zapisovala do mýho vědomí jako na čistej papír.

Kde jinde se slizký ropuchy mění v krásny pricezny než v pohádce? A kde jinde se špinavá práce může změnit v královskou zábavu?
Asi nikdy nezapomenu na šmirglování záchodové budky přímo nad výtokem... společně s M. jsme u toho probírali raní zamyšlení od K. Asi nikdy nezapomenu na oživnutí sálů umřelýho kláštera v P. pod přívalem tonů piána a houslí. Asi nikdy nezapomenu na proměnu hromady popelnic a hrnců v bicí soupravu, ani na kronikářovo nezastavitelný vyprávění mimo kameru o bolavých česko-německých záležitostech. Stejně tak na jeho záchranu před zlou policistkou.

Jen škoda, že se se všema těma odpohledu simpatickýma lidma, co se tam sjeli, nešlo pořádně seznámit. Asi to byla taky součást pohádkovýho zjevení co se objeví a zmizí.
Každopádně organizátorům a Bohu díky.
 

Theoretical Computer Science

(A kind of professional confession, mini observations, not a scientific study.)

Is a math field I am fan of. It's a field where you can be an engineer and an artist at the same time. It is an excellent modern success story for the old business started by grandpas Euclides, Pythagoras, Archimedes and co. Let me explain briefly:

• One gets in touch with math behind computers every day: searches the web (freshmen linear algebra), listens to the mp3s (sophomore linear algebra inspired by some analysis and complex numbers), uses the DVDs with error correcting codes (advanced linear algebra again: finite fields and polynomials) or encrypts his bank orders (again, not so advanced algebra). I omit many many other occasions..
• "Computers" outpaced "physics" and competes with "fields around finances" in motivating the math research. My guess is they are number one.
• Unlike materialized computers themselves, the theory behind them is elegant and beautiful: It intersects most of the classical math fields (that were often developed without a slightest dream of computers, and advent of computers has given them a new meaning, what a postmodern art) and many of its important results exhibit diversity and freshness of ideas.
• I want to avoid researching in well established (and possibly important) fields of mathematics, where the state-of-the-art cannot be understood by anybody else than experts. I prefer spending half of my time searching for new coming questions, answering which is of higher relevance (namely because the answer can be understood). Theoretical computer science offers many such questions.
• There is the fabulous P versus NP problem in the heart of the theoretical computer science. It can be explained to high school students (unlike the Riemann hypothesis), has a huge importance (unlike the Fermat last theorem) and is the biggest frustration of the current mathematics: the state-of-the-art seems to be not much further than the "high school level of understanding". An interesting link (not for complete outsiders): http://www.cs.umd.edu/~gasarch/papers/poll.pdf

The previous might sound like TCS is a science utopia. Of course, I can share some negative impressions as well:

• The level of rigorousness of papers (and books) is rather poor compared to other math. As a consequence, there are serious mistakes in them very often or, at least, the papers are difficult to understand. This might be consequence of the fact that many (despite very clever) theoretical computer scientists were trained rather in programming than in general mathematics during their undergraduate studies. In addition, in TCS, publishing papers is rewarded with quite attractive travelling for conferences, (in other math the travelling is rather independent) so TCS people are more motivated to publish papers as frequently as possible at the expense of mathematical quality (that is time costly and its lack is not obvious at first glance).
• There is more hypocrisi in TCS than in other mathematics: often people just make up fake applications of their result in the introduction of their paper to make it look more attractive. Also they sometimes try to use fancy mathematics just because it is fancy mathematics.

Připálený dobroty

Často, když se zamyslím nad tím, jakže přišla na svět některá z mých oblíbených chuťí, dojdu k tomu stejnýmu kuchařskýmu paradoxu: prudkým žárem: ne možná každý bude souhlasit s přísným termínem "přípálení", ale minimálně "pražení" to je. Příklady?

• káva
• čokoláda
• karamel
• buráky a pistácie
• kůrka chleba
• povidla (tady bych za to ruku do ohně nedal, ale myslím si, že i v tomto případě teplota přesáhne stovku)

Samý dobroty, a to jsem určitě na další zapoměl. Kdo ví, co dalšího může vzniknout šťastným omylem třeba právě ve vaší kuchyni?

Je to sice velká legrace, když děti kreslí krávu fialově, co takhle ale zkusit požádat dospělýho matematika (/programátora/manažera) aby namaloval semena kávovníku:) ?

The nicest city the most miserable

Mathematical academical life has given me many opportunities to visit cities around Europe, to enjoy more than just a small amount of time there and not to run the usual stressing touristic race around all "must-see" sights.
On the contrary, I was able/had to take the viewpoint of an ordinary inhabitant and take at least a sip of a daily life there. This formed my view on cities in general as well as my opinion on many European metropoleis.

• I have great memories of Amsterdam, (among other reasons) for its public "street night skating" with a friendly atmosphere run weekly (dry streets permitting) all year round.
• I admire Paris for its incredibly dense net of rental spots of city-bikes, that can be used for a very friendly price.
• A great example of competition in public transportation can be found in Catalan metropolis: three different metro/railway systems (more or less successfully) work hard for the comfort of people of Barcelona.
• My biggest impression from my short visit of Zurich were the modern terraces built onto old roofs of almost all buildings around our hotel and people enjoying silent evenings with beautiful views from there.

Of course, for your life (in a city), the thing that matters most is other people around. But should the city be an obstacle for the life of "your community" or a pleasant environment? Should the city serve to the tourists, preservationists, and historicians or to its inhabitants?

So what about "my city"? No matter how hard I think, I can not figure out any reason why should I include it into my nice list. Can you help me somebody, please?
I would love to change my view of the city of Prague as the most beautiful, the most miserable.

The year 2009

My



year 2009 was heaven and hell. It brought me both the best and the worst three months of my life.
My life-time came on winter (math) doctorand course in Barcelona. Let me skip the boring enumeration of factors, that made the unique blend of conditions of my dreams. I just suply you with an evidence of what it meant for my mates there: among the best results of the doccourse were three brand new couples. Considering the usual gender imbalance of math communities, you won't be surprised by the fact that the doccourse pushed the outcome very close to its theoretical heterosexual limits.
The catastrophic period came surprisingly soon - in the summer, not surprisingly it is located in Prague, mostly. If I were to characterize the reasons in one word, I would say frustrations. Frustrations caused both by my stupid expectations/plans and bad planning as well as by unlucky coincidences of failures, external reasons. I don't wish anybody to experience such a black spiral of depressions and lost self-confidence, but as long as one survives, I believe, he can even make good use of such crisis, after all.
Anyway, getting into troubles is always easy, the miracle of the year was definitely my return back to earth. The process was a long and complicated story but if I had to pick a single moment that kicked me most in the right direction, it would be trip to Berlin in September (for the doccourse reunion). In general, staying active at all cost was the right cure, but I can't deny a touch of love and happiness from "above" as well.
How will the year 2010 look like? Am I immune to the following storms my life? Definitely not entirely. More feel like a small boat in the ocean. But the current weather is more than good.

Visual Memory Rocks

The preparation for my doctoral exams gave me a lecture about math learning: at the first place there are pictures, at the second place there are pictures,... and only at the third place... there are pictures.

OK, this statement has some exaggeration in it, yet, I really shocked myself how much I depend on having some drawing in front of me (or any kind of visual perception), when somebody explains me math. Hearing just words doesn't work at all.
Even if I analyze the way how I remember math ideas, I get that  they are mostly pictures what stays in my head. (Words are just a bonus that can be attached to the necessary picture in my memory.) A rather boring example case analysis follows:

For example even such non-visual theorem like Chernoff bounds: At the first place, there is the Gauss distribution: the famous "hilly curve" that lies on x-axis having the y-axis in the middle. Then there is one more vertical line the right side of the y-axis, quite close to it, which is telling: "although I lie close to y-axis (distance C) only (exponentially in -C squared) small ratio of the mass (of the Gauss distribution) lies on the right side from me". And there is also formula picture (it also has a picture-like nature) where one important place is in the probability brackets (there is the C\sqrt(n)) which influence another place in the exponent of e (after the "<" sign) where is something like C squared times 2.

Recalling some of the experiences from the lectures I recently took, I also have to say, that the teachers are speaking unnecessarily much. Most of the words just flow through my head. Now I believe that what I rather need is pictures (or even animation/movie) on the blackboard that can be additionally accompanied by explanations and important keywords. Do the teachers teach bad in general or am I an E.T. by accident thorwn on the planet Earth? What do you think?

By the way, if you accept my first claim of this note, don't you think that from this point of view the glorified LaTeX just sucks?:)
But that is for another chapter.