## lunedì 28 febbraio 2011

### [For fun] Paperino e la Bella del Ballo

Scena: Paperino è infilato in un bidone dell'immondizia, a testa in giù. Attorno a lui si raduna una folla.

Un signore: Povero papero, deve essere così povero che cerca un tozzo di pane nella spazzatura!

Qui, Quo e Qua: Sì signore, nostro zio è così povero che non possiede nemmeno un pezzo di pane da mangiare.

Una signora: Allora questo papero è vostro zio?

Qui, Quo e Qua: No signora, nostro zio è così povero che non possiede nemmeno tre nipotini!

(liberamente tratto da: Paperino e la bella del ballo, testi di Guido Martina, disegni di Pier Lorenzo De Vita)

## domenica 27 febbraio 2011

### Mac OS troubles

You probably know that I am a Macintosh user. Well, I also run a few GNU/Linux machines, but my personal computers use Mac OS Snow Leopard.
It is a rather good operating system, and yet a few issues cannot be ignored.
The most troublesome is that the system becomes slower and slower when you use it for some months. This is well known to Microsoft Windows users, but looks strange to Linux addicts. My Slackware machine has been running for one year, and it is as fast (or as slow) as it used to be when I installed it. So, what's wrong with Mac OS? I went on the Internet, and people say that every computer gets slow as it grows older. This is a stupid principle, in that it may be true only if you add more and more activities your machine should do.
So I checked my hard disk, my RAM, even the fragmentation rate of my files. But it is a fact that a virtual machine can run Linux faster than the true computer can run Mac OS!

Any guess from experienced Mac users out there?

## sabato 26 febbraio 2011

### Toss a coin?

I have just checked my calendar, and I have found out that next Thursday I should attend two different seminars in three different places. And I should also interview a student. I can either discover a way of splitting myself into several pieces, or make a choice.

## venerdì 25 febbraio 2011

### My latest paper

You can finally download my latest paper in collaboration with... B. Riemann!

scimakelatex.91097.Simone+Secchi.B.+Riemann

Of course this is just a fake, generated by SciGen

### We are more or less the same

This post is a funny tribute to a sentence I heard from my friend Alessio Pomponio. We were PhD students at SISSA, and we were working together on some problem. One day, he said that most mathematicians always write the same paper, up to minor changes.

I won't spend much time claiming that this is false, that we always publish original and brand-new papers, etc etc. Indeed, sometimes I agree with Alessio. I'd rather comment on a feeling that, I'm sure, every (young) scientist is familiar with: it is rather easy to guess the content of a talk, once you know the speaker. By this I mean that Prof. Smith usually speaks about, say, the beauty of pets in medieval France; Prof. Doe speaks about the p-laplace operator; prof. Black speaks about the influence of the spanish flu on the development of commutative rings. Well, this is quite obvious, since contemporary science is so specialized that a chemist can't know enough mathematics to publish a mathematical paper (this is just an example). I heard that in a very recent book this problem of specialization is deeply discussed and criticized. I have not read that book, yet.

Of course, there are exceptions. I personally know a few mathematicians that publicly speak about different topics (though in the same general field of mathematics) and the audience is always fascinated by their deep understanding. And yet they are the exceptions.

In 2010 I was kindly invited to speak during a summer school, and a small group of colleagues was quietly discussing about the program. One of them sayd, more or less: Simone Secchi is from Italy, and therefore he will speak about Nonlinear Schroedinger Equations. Well, of course he/she was right! Sometimes I feel like I first find the solution and then I find the problem solved by my solution. If you browse the collection of scientific journals in a library, you will remark that this happens quite often. A lot of research papers are published because nothing better could be done by the authors. A friend of mine said: you work for some months on your problem, and you can't solve it. However. you can still publish all the computations you have done and promise to solve the problem in a future paper. Sad but true.

Ok, now I must go: I want to find a problem I can solve!

## giovedì 24 febbraio 2011

### Human behavior during seminars

If you are a scientist, or a friend of a scientist', or just somebody who passes by near a university, you probably know what I am writing about. A seminar (aka talk, piece of a conference, etc) is a period of time that usually lasts 45 minutes of an hour, and seems to last more or less one century. I am not joking: if you attend a seminar because you really like the speaker or the topic, you'll soon find out that the amount of ideas, definitions, theorems that slide on the screen is too much even for the bravest audience. If you attend the seminar because your boss told you to do so, time will stop forever.

Anyway, I wish to spend a few words about those strong and brave people that populate the seminar room. I do not pretend I am the first one to write about this, but anyway I'll do.

No matter if you are in the first row or at the very bottom of the room, everybody around you will start oscillating his/her head like a pendulum going up and down. And, like a physicist of the 17th century, experience teaches you that the oscillation increases when the speaker looks at the audience. Beware: just a few of them can really understand the speaker's words, but everybody wants to look like he/she could even improve the speaker's seminar.

Needless to say, this is generically false: the seminar usually deals with results obtained over the years, and it is completely natural if the audience gets lost after 20 minutes. And then, something happens: like a flood, or like a wave, each man or woman in the room wears a very peculiar expression, the eyes stare at the point at $latex \infty$ and their minds run so fast towards the coffee/tea break.

Some particularly trained guys can now focus their attention on that very difficult proof that seems to resist to their assaults, but most will just sit down and wait for the climax: the long applause that every audience must tribute to the speaker. Well, there is another embarassing moment: the final "Questions? Remarks?". Unless you wrote a paper with the speaker, or unless you are a true genius, you will feel like at school, when your teacher was waiting a clever answer from you and you had no clever answer at all.

To finish, I confess that seminars are a most important part of every scientist's life. You can't select those seminars in which you can learn something. Just listen and hope, because there is no better way to improve knowledge than listening and learning.

### A seminar or not a seminar, this is the question

A few days ago I was browsing the most important database for mathematicians, Mathscinet, and I found a really interesting paper by J. Mawhin and M. Willem. Its title is Origin and evolution of the Palais-Smale condition in critical point theory. While traveling home, I could read almost all of it, and I was so amused that I decided to prepare a rather informal talk for PhD students.

Therefore, I stated writing slides, but I suddenly stopped: is this really interesting for students? I mean, they do not know what the Palais-Smale condition is, why should they be interested in its evolution? Even worse, why should they be interested in mathematics at all? Alright, this is too much...

### I am flattered, but...

A couple of weeks ago, a scientific journal invited me to review a paper. It deals with a nonlinear equation on an annulus, like $latex \{x \in \mathbb{R}^n \mid 1<|x|<3\}$. It looks nice, the proofs are correct, but... it is copied almost word-by-word from a paper of mine (a joint work).

Ok, I am flattered that some guys, out there, judged my paper worth copying, but this is too much. I am still looking for the best words to refuse the manuscript.

### Feuilleton da viaggio

In questi giorni sto leggendo Raccolto di Sangue, di Sharon Bolton. E' il tipico libro thriller da viaggio, e non a caso lo leggo in treno. Sono arrivato solo a pagina 150, quindi evito di sparare giudizi affrettati. Gli ingredienti per il romanzone gotico dell'Ottocento ci sono tutti: il villaggio inglese, le chiese abbandonate, il cimitero, i bambini morti tragicamente, i fantasmi dei bambini morti tragicamente, il giovane vicario allupato (protestante, altrimenti in Italia non sarebbe stato pubblicato), la giovane psichiatra disabile, ecc. ecc.

Un po' banale, vero? Ma la banalita' e' soprattutto la ripetizione dei temi piu' fortunati.