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Friday, May 23, 2008

Logarithmic Spirals



Image Credit: M101 - NASA, ESA, CFHT, NOAO; Typhoon Rammasun - MODIS, NASA
Comparison: Lawrence Anderson-Huang (Ritter Astrophysical Obs., Univ. Toledo)

Explanation: Uncomfortably close Typhoon Rammasun (right) and 25 million light-year distant galaxy M101 don't seem to have much in common. For starters, Rammasun was only a thousand kilometers or so across while M101 (aka the Pinwheel Galaxy) spans about 170,000 light-years, making them vastly dissimilar in scale, not to mention the different physical environments that control their formation and development. But they do look amazingly alike: each with arms exhibiting the shape of a simple and beautiful mathematical curve known as a logarithmic spiral, a spiral whose separation grows in a geometric way with increasing distance from the center. Also known as the equiangular spiral, growth spiral, and Bernoulli's spiral or spira mirabilis, this curve's rich properties have fascinated mathematicians since its discovery by 17th century philosopher Descartes. Intriguingly, this abstract shape is much more abundant in nature than suggested by the striking visual comparison above. For example, logarithmic spirals can also describe the tracks of subatomic particles in a bubble chamber, the arrangement of sunflower seeds and, of course, cauliflower.

(sub-repticiamente gamado ao António)

Wednesday, May 21, 2008

Citação do dia

"To be GOVERNED is to be watched, inspected, spied upon, directed, law-driven, numbered, regulated, enrolled, indoctrinated, preached at, controlled, checked, estimated, valued, censured, commanded, by creatures who have neither the right nor the wisdom nor the virtue to do so. To be GOVERNED is to be at every operation, at every transaction noted, registered, counted, taxed, stamped, measured, numbered, assessed, licensed, authorized, admonished, prevented, forbidden, reformed, corrected, punished. It is, under pretext of public utility, and in the name of the general interest, to be place[d] under contribution, drilled, fleeced, exploited, monopolized, extorted from, squeezed, hoaxed, robbed; then, at the slightest resistance, the first word of complaint, to be repressed, fined, vilified, harassed, hunted down, abused, clubbed, disarmed, bound, choked, imprisoned, judged, condemned, shot, deported, sacrificed, sold, betrayed; and to crown all, mocked, ridiculed, derided, outraged, dishonored. That is government; that is its justice; that is its morality."

Pierre-Joseph Proudhon, General Idea of the Revolution in the Nineteenth Century

Tuesday, April 15, 2008

we all have inner daemons, mate


Demons from Hellgate: London at a pub, drowning their sorrows. Intel-powered computers are making their lives miserable.

Pequena nota v4.0



Desde finais de Fevereiro, há, finalmente, telefone fixo e ADSL por aqui. Os problemas, contudo, não terminaram e alguns não estão ainda definitivamente resolvidos. Mais pormenores provavelmente em Junho, quando fizer um resumo alargado da odisseia - ou, com maior exactidão, doze trabalhos de Hércules - e do registo de sapos (de certa forma, literamente) engolidos.

Anteriores: pequena nota v1.0; pequena nota v2.0; pequenota nota v3.0

Saturday, April 12, 2008

com as próprias mãos

X está internada há mais de uma semana por ter sido esfaqueada pelo (ex-?)namorado da filha, tendo ficado com o fígado e o baço perfurados. Também a filha ficou com uma perfuração num pulmão como resultado da mesma agressão, embora tenha tido alta no dia anterior. O perpetrador é reincidente; já tinha cometido algo idêntico em Novembro. Foi preso e celeremente presente a um juíz, mas saiu em liberdade, sem qualquer medida de coacção aplicada. Foi feita nova queixa às autoridades - com o ânimo próprio de quem se encontra entre a espada e a parede e não tem qualquer esperança em ver nada resolvido - mas o homem continua à solta e a lançar ameaças de morte, as quais aparentemente ainda não se concretizaram por mero acaso. A Associação Portuguesa de Apoio à Vítima (APAV), na falta de melhor conselho e para desespero de X, recomenda a mudança imediata de residência. Alguns presentes sugerem que a melhor solução é adquirir uma arma para matar o meliante da próxima vez que este as invective, embora isso provavelmente signifique que serão as próprias vítimas a ser detidas, apesar de agirem em legítima defesa, corrigindo um problema para o qual já a justiça portuguesa deveria ter encontrado uma resolução definitiva há muito tempo atrás. Complicado. Arranjar uma arma de fogo de forma legal é extremamente burocrático, senão mesmo impossível na grande maioria das circunstâncias, restrições estas que são impostas para alegadamente salvaguardar a segurança dos cidadãos. Restrições essas que não impediram um homem de esfaquear duas mulheres, nem agiram de forma a prevenir futuras tentativas de assassinato. Assim como não lhes permitem protegerem-se a si mesmas com algo mais do que uma faca de cozinha. De um dos lados da sala, um dos mais anciãos solta o comentário que provavelmente terá passado pela cabeça de muitos dos suficientemente idosos para partilharem da mesma opinião: "Isto no tempo do Salazar não era assim". Os mais jovens olham de forma desconfortável entre si, como se não tivessem outra solução senão aquiescer tacitamente, quando se pressuporia, de forma implícita, que, como representantes naturais do paradigma político actual e da sociedade contemporânea, teriam de possuir três ou quatro argumentos de algibeira que contrapor de imediato.

Saturday, March 29, 2008

hear, hear

"Twenty years later I find computer security, frankly, to be kind of boring. It's tedious. The first time you do something - it's science. The second time it's engineering. The third time it's just being a technician. I'm a scientist. Once I do something, I want to do something else."

MAD

Microsoft takes on the free world (Roger Parloff, Fortune)

[N]ow there's a shadow hanging over Linux and other free software, and it's being cast by Microsoft. The Redmond behemoth asserts that one reason free software is of such high quality is that it violates more than 200 of Microsoft's patents. And as a mature company facing unfavorable market trends and fearsome competitors like Google, Microsoft is pulling no punches: It wants royalties. If the company gets its way, free software won't be free anymore. (...) Revealing the precise figure for the first time, they state that FOSS infringes on no fewer than 235 Microsoft patents. It's a breathtaking number. (...)

The free world appears to be uncowed by Microsoft's claims. Its master legal strategist is Eben Moglen, longtime counsel to the Free Software Foundation and the head of the Software Freedom Law Center, which counsels FOSS projects on how to protect themselves from patent aggression. Moglen contends that software is a mathematical algorithm and, as such, not patentable. (The Supreme Court has never expressly ruled on the question.) In any case, the fact that Microsoft might possess many relevant patents doesn't impress him. "Numbers aren't where the action is," he says. "The action is in very tight qualitative analysis of individual situations." Patents can be invalidated in court on numerous grounds, he observes. Others can easily be "invented around." Still others might be valid, yet not infringed under the particular circumstances. (...)

Furthermore, FOSS has powerful corporate patrons and allies. In 2005, six of them - IBM, Sony, Philips, Novell, Red Hat and NEC - set up the Open Invention Network to acquire a portfolio of patents that might pose problems for companies like Microsoft, which are known to pose a patent threat to Linux. So if Microsoft ever sued Linux distributor Red Hat for patent infringement, for instance, OIN might sue Microsoft in retaliation, trying to enjoin distribution of Windows. It's a cold war, and what keeps the peace is the threat of mutually assured destruction: patent Armageddon - an unending series of suits and countersuits that would hobble the industry and its customers.

"It's a tinderbox," Moglen says. "As the commercial confrontation between [free software] and software-that's-a-product becomes more fierce, patent law's going to be the terrain on which a big piece of the war's going to be fought. Waterloo is here somewhere."
Leitura complementar: The Total Growth of Open Source

Wednesday, March 26, 2008

for any excuse

Milton Friedman:
I am in favor of cutting taxes under any circumstances and for any excuse, for any reason, whenever it's possible. The reason I am is because I believe the big problem is not taxes, the big problem is spending. The question is, "How do you hold down government spending?" Government spending now amounts to close to 40% of national income not counting indirect spending through regulation and the like. If you include that, you get up to roughly half. The real danger we face is that number will creep up and up and up. The only effective way I think to hold it down, is to hold down the amount of income the government has. The way to do that is to cut taxes.

'Tis but a scratch



Parece que o exército da República Popular da China andou por aí a matar dezenas de tibetanos. Jerónimo de Sousa, grande defensor do direito de soberania dos iraquianos face ao imperialismo norte-americano, assim como dos direitos humanos dos prisioneiros de Guantánamo e Abu Ghraib, está preocupado com a possibilidade de que esta insurreição (tibetanos maus! sentem! rebolem!) no território ocupado pela RPC em 1950 tenha como objectivo comprometer a realização dos jogos olímpicos em Pequim. Comovente.

Adenda: PCP vota sozinho contra condenação da violência no Tibete

A brief history of violence


A HISTORY OF VIOLENCE, artigo baseado na apresentação:

Once again, Steven Pinker returns to debunking the doctrine of the noble savage in the following piece based on his lecture at the recent TED Conference in Monterey, California.

This doctrine, "the idea that humans are peaceable by nature and corrupted by modern institutions—pops up frequently in the writing of public intellectuals like José Ortega y Gasset ("War is not an instinct but an invention"), Stephen Jay Gould ("Homo sapiens is not an evil or destructive species"), and Ashley Montagu ("Biological studies lend support to the ethic of universal brotherhood")," he writes. "But, now that social scientists have started to count bodies in different historical periods, they have discovered that the romantic theory gets it backward: Far from causing us to become more violent, something in modernity and its cultural institutions has made us nobler."

Pinker's notable talk, along with his essay, is one more example of how ideas forthcoming from the empirical and biological study of human beings is gaining sway over those of the scientists and others in disciplines that rely on studying social actions and human cultures independent from their biological foundation.

Sunday, March 23, 2008

It's a trap!

Jornal publica opiniões sobre reformas do governo

O presidente cubano decidiu abrir o jornal oficial Granma à opinião dos cidadãos do país seja ela contra ou a favor das reformas que estão a ser promovidas pelo governo cubano.