Rating systems

Just something short on (elo) rating: http://www.ratingtheory.com/

When posting about rating for games, just some nice games of starcraft:

http://www.gomtv.net/videos/638

Also the youtube channels of moletrap, VioleTAK, diggitySC, CholeraSC have some more nice games.

Music and sound

http://lab.andre-michelle.com/tonematrix is something to play around, http://www.hobnox.com/audiotool looks pretty awesome at the first view!

Persistence of intuitive beliefs

At Helen's blog at the cognition and culture is a short article about intuitive vs scientific explanations. Some of the comments posted there are also interesting.

By the way, I included the snap shots feature. For those who dislike it, disabling it is quite easy via the drop down menu at the top right corner of each snap shot.

Futhermore I moved the few german-only postings to a new blog and won't bother readers of this one with more german writings.

Completness and compactness theorems

Nice article with draft of proofs:

http://terrytao.wordpress.com/2009/04/10/the-completeness-and-compactness-theorems-of-first-order-logic/

Osterpredigt Teil 1

Due to the indended nature of this blog, I moved this posting to http://misohuroipensi.blogspot.com/2009/04/easter-homily.html.

Some more ...

Just two links: http://www.openculture.com/ and http://youtube.com/edu ...

[edit] fixed for snap shots

Illusions

An interesting blog article named "Hallucinatory neurophysics
" can be found here: http://preposterousuniverse.blogspot.com/2005/02/hallucinatory-neurophysics.html. Unfortuntally I wasn't able to find the paper by now. (There are, by the way, some nice videos about hallucinatory drugs on youtube, and some good articles in Spektrum). And Jack Cowans appointment to math and neurology also sounds pretty interesting. Computational neuroscience seems to be a field of its own.
I came there via a blog about "imagining more than 3 dimensions" at http://blogs.discovermagazine.com/cosmicvariance/2009/03/30/why-cant-we-visualize-more-than-three-dimensions/.

That previous blog post reminded me of the "Imagining the tenth dimenson" video ( http://www.youtube.com/watch?v=XjsgoXvnStY ) which I first watched years ago. This version contains some annotations taken from the book (for which the video is supposed to be pomotional material I guess). I found them not too easy to follow and I doubt the correctness of some claims. But to discuss this I'd need the book, but one at the first glace strange thing is his integration of Everett's many-world interpretation of quantum physics.

edit: I found a paper which seems to have a similar focus: "Geometric Visual Hallucinations, Euclidean Symmetry, and the Functional Architecture of Striate Cortex" at http://www.math.utah.edu/~bresslof/publications/01-1.pdf