David S. Richeson - Euler's Gem

Read from-to: Feb 19, 2010  - Mar 14, 2010 (24 days).

Liked: ...it's math, what's not to like?


Didn't like: al final se pone un poco denso y pierde un poco las ayudas visuales (que es entendible, hablando de n-dimensiones no sirven de mucho, pero hay algunas que no son tan triviales de entender con la poca explicación que da).

Overall: nice book =D.

Get it here.

Notes & Quotes:

"Mathematical folklore says that he [Euler] could write mathematics papers while bouncing a baby on his knee, and that he could compose a treatise between the first and second calls to dinner" (p.16)

"Later he [Pythagoras] settled in the Greek city of Croton in what is now southern Italy" (p.37).

Italia? Interesting...

"I hope that posterity will judge me kindly, not only as to the things which I have explained, but also to those which I have intentionally omitted, so as to leave to others the pleasure of discovery" - Rene Descartes (quoted in p.81).

Riiiiiiiight jaja.

There is a oft-repeated quip that "objects in mathematics are named after the first person after Euler to discover them" (p.86)

Jaja THAT's fame.

La prueba de Legendre [JAJAJA la caricatura en wikipedia =P] de la fórmula de Euler, en el capítulo 10 (pp.87-99)... wow. Beautiful. Too long to transcribe though.

G. H. Hardy wrote "Reductio ad absurdum, which Euclid loved so much, is one of a mathematician's finest weapons. It is a far finer gambit than any chess gambit; a chess player may offer the sacrifice of a pawn or even a piece, but a mathematician offers the game" (p.123).

"Ok, you win, it is false. But HA! That means it's true! IN YOUR FACE!"

Any knot can be obtained as the boundary of an orientable surface with one boundary component (p.185).

Mathematicians work in a store that makes and sells tools. Occasionally they take special orders from their scientific customers, but most of the day they toil away making elegant tools, the uses for which have not yet been invented. Scientists visit this tool shop and browse the shelves in hopes that one of the tools fits their needs (p.201).

Nice description.

Poincaré had a restless curiosity that kept him moving from topic to topic. He would attack a new area of mathematics, make an indelible mark, then move on the the next. A contemporary called him "a conqueror, not a colonist" (p.212).

Otra buena descripción.

Back to learning music

Hace un buen rato que no aprendía a tocar alguna canción nueva. Cuando estoy cerca de un instrumento —a veces es mi guitarra, a veces el piano en casa de mi tía— y traigo alguna melodía en la cabeza, me da por intentar "transcribirla" y tocarla, pero por lo general no pasan de ser sesiones de 5 min o menos, que terminan sin importar si tuve o no éxito en mi intento.

A diferencia de eso, hoy busqué el tab de Trains (Porcupine Tree), que tenía finta de no ser muy complicada, y efectivamente el 90% de la canción salió sin problemas tocando del tab a primera vista. El solo y un bridge fueron lo único que tuve que ponerme a sacar de oído, pero después de un rato salieron (wu! =D) and now I'm happy to say there's a new song in my repertoire! Una que disfruto mucho escuchar, y ahora también tocar. Great way to end the day.

When the evening reaches here, you're tying me up... I'm dying of love... it's ok...

Learning about my limitations

Hoy leí el post Hearing the Uncertainty Principle, que aparte de estar interesante me dio la excusa... ejem... explicación, perfecta, de por qué me es mucho más difícil sacar de oído melodías rápidas que melodías lentas. Y dejando al ego de lado, por qué es más difícil sacar de oído melodías rápidas que melodías lentas. It seems obvious enough, pero tener un por qué siempre es bueno. Entre más larga sea una onda en el tiempo, más angosta su representación en frecuencia, y entonces se parece más a una nota pura. Notas muy cortas en el tiempo implican un espectro de frecuencias mucho más amplio, que hace bastante más complicado determinar cuál es la frecuencia (nota) principal del sonido.

Ta-ran!

Analogy on software engineering & PEBKAC

Leyendo los comentarios de un post de reddit donde Peter Norvig (director de investigación en Google) contesta preguntas hechas por la comunidad me encontré este (contexto: Norvig habla de la diferencia entre Civil Engineering y Software Engineering, y construir puentes VS construir programas):

Imagine that one day, one of your users (a driver) decides to drive off the bridge. In civil engineering, it isn't your fault, it's his. In Software, it is your fault. You would have to have thought about a way of preventing that. Thats akin to saying that when a driver is about to drive off a bridge, a huge rubber wall should instantly appear bouncing him into the bridge again. This wall should have the message "The operation you tried to do is not allowed".

En otras palabras, el problema del desarrollo de software es que en caso de PEBKAC (Problem Exists Between Keyboard And Chair), la culpa recae sobre el programador en vez de sobre el Between-Keyboard-And-Chair. Maldito mundo injusto =P.

La "entrevista" completa de Norvig está aquí. El comentario original acá.

Definición de "fama"

There is a oft-repeated quip that "objects in mathematics are named after the first person after Euler to discover them".

Need I say more?

Neil Gaiman - The Graveyard Book

First post in the "Books I've read" series/category.

Read from-to: Feb 4, 2010 (aprox) - Feb 18, 2010 (14 days).

Liked: the Macabray related verses (Time to work and time to play, time to dance the macabray; step and turn and walk and stay, now we dance the macabray)

Didn't like: it's much more like a child's story than I expected (especially after reading Sandman... awesome comic).

Overall: not too long, finished half the book in one chunk... mildly entertaining. Didn't meet my expectations.

Video. Just sharing.

Entre mis feeds encontré este video, que está largo pero entretenido e interesante, sobre todo la parte que empieza en el 20:57 aprox.

Kiss a lover, dance a measure...

find your name,
and buried treasure...

- from Neil Gaiman's The Graveyard Book

Fail

Poetry

Brilliant. Sublime. So much emotion.

Enjoy.

Alguien debería escribir un libro así.