by Douglas Hofstadter

I first heard about the book last year at Dagstuhl, in a discussion with Stephen Koburov. Now that I read it, I am grateful to Stephen for pointing me to an an Extremely Good Book.

In GEB, Hofstaedter performs an entertaining intelectual slalom between fugues, paintings and incompletness theory in order to eventually arrive at the finish line: the discussions on artificial inteligence. Even if I happen to disagree with the author on his optimism about the the emergence of artificial inteligence, I found the book to be a remarcable lecture.

The topics discussed in the book are various. Mathematics. Music. Goedel. Recursivity. Bach. Programs. Genetics (i found this part extremely nicely written). Intelligence. Formal systems. Programming languages. Escher. Margitte. And all of them, braided with the notorious dialogues between Achiles, the Tortoise and their friends, but all of them supporting a single thesis.

One great peculiarity of GEB is the playful unity between form and content. One of the many possible examples of tight unity is the dialogue in which Achilles tells the Tortoise about an author who invented a type of dialogue which would have a logical ending followed by extra paragraphs that would serve as a device to hide the real ending; because the extra paragraphs would be logically unrelated to the dialogue, the careful reader would still be able to spot them. As one already expects when he got that far in the book, the dialogue has a logical ending followed by extra paragraphs that serve as a device to hide the real ending; because the extra paragraphs are logically unrelated to the dialogue, the careful reader will still be able to spot them…

Two are of my ultimate favourite sections in the book. One is the part in which H. explains the self as being a symbol in our brain, but a special one, the one which is associated to our body. We have symbols for all the concepts but as this is all the time involved, as this is the one whrought wich we can make sense of all the others, it is natural that we have a more special relation with it. The second part is the one on typogenetics - a simplified version of genetics which shades light on the amazing way in which the genetics work.

I could write much more about it but maybe another time. My advice now is just Escape and Get the Book!

Viktor Frankl in The meaning of life:

“We, who lived in concentration camps, can remember the men who walked through the huts, conforting others, giving away their last piece of bread. They may have been few in number, but they offer sufficient proof that everyhing can be taken from a man but one thing: the last of the human freedoms - to choose one’s atitude in any given set of circumstances, to choose one’s own way.”

This reminded me of a discussion with Cy and Jeff in which I was arguing for total determinism. The more I think, I realize that beyond being not fun, that position might also not be right. Or at least not always…

How does the passwordless ssh login work? Simple. The user sends his public key along when attempting to connect. If the key is found in the .ssh/authorized_keys on the server, the server sends a random number encrypted with the public key to the client. The client being in the possesion of the private key is able to decrypt the message and answer and is therefore authenticated.

The two lines solution for ssh-ing without password is:

(1) ssh-keygen -t rsa #generate the rsa keys, if you did not do this before
(2) cat .ssh/id_rsa.pub | ssh ‘cat >> ~/.ssh/authorized_keys’ # append the public key to the authorized keys on the server

Note that the solution could be a one liner if you already have the rsa keys generated before (e.g. you are setting up the passwordless login for a second server)

There were many days when I felt like the time flew too fast and I did not do enough. This pressed my mind for a long time. I even felt pretty bad about it.

It was only after I read Popleware that I realized that I am not an isolate case. This was not my problem, it is our time’s intelectual worker’s problem (and I challenge you to oppose me if you feel that I am wrong).

An article in wired observes that we have real reasons to be frustrated - we truly get less things done. And the reason is partly the technology. Beautiful things as blogs, news, RSS feeds interrupt us too often. We get too much unwanted mail… too many phone calls and too many sms’s. In fact, the first impulse when I read the article was to send it on the PhD mailinglist… But then I decided that there was no need to further prove the article contents with my own action.

Even if a problem does not go away if you realize it, I think that realization is the first step towards the solution. And I guess I will find if this is right if sometime I will write another wntry here on how did I solve the problem. Or maybe I will stop writing entries here, and that would have solved the problem. Who knows?

Polyadenylation occurs during and immediately after transcription of DNA into RNA. After transcription has been terminated, the mRNA chain is cleaved through the action of an endonuclease complex associated with RNA polymerase. The cleavage site is characterized by the presence of the base sequence AAUAAA near the cleavage site. After the mRNA has been cleaved, 80 to 250 adenosine residues are added to the free 3′ end at the cleavage site. This reaction is catalyzed by polyadenylate polymerase.

This is the kind of stuff I have to read through in order to prepare my survey on biomedical visualization. If it was chinese, I would not feel that bad, but seing that it’s english made me feel pretty unconfortable