// μ = m // dayvan cowboy // music is math

A rua Nelson Mandela continua sendo um pedacinho de vida entre a São Clemente e a Voluntários. É difícil que isso mude. A rua enquanto faixa de cimento de duvidosa utilidade para o trânsito pode ser cancelada para a construção de mais de um desses conjuntos residenciais que têm brotado no início da Voluntários, mas eles não a porão num outro lugar porque uma faixa de cimento com placas nas duas pontas não é uma rua, e muito menos a rua Nelson Mandela. E no entanto, eles fecharam a fábrica.

Eu nem lembro que fábrica era. Lembro-me dos cartazes propagandeando o número de dias sem que ninguém perdesse um dedo ou uma perna — com os números em branco, no entanto. E antes dos números em branco havia números, e antes desse terreno baldio havia uma fábrica.

Os aforismos repetitivos dos seguidores de Kundera estão certos: fábricas são efêmeras, bacon é eterno. Eu deveria ter pressentido quando o inefável pipoqueiro a quem eu pedia um saco de bacon com bastante pipoca não tinha troco para a minha nota grande. Este é um pipoqueiro para uma pessoa que contava as moedas e contava com o ônibus do condomínio para comprar aquele bacon borrachudo e quentinho com o qual hoje, sem fome, esperava esquentar os meus dentes gelados.

Não tive a pipoca, porque não era mais o meu pipoqueiro e não vi a fábrica. E sentei-me então no cimento gelado que cerca aquelas grades por onde entra luz do dia ao metrô. Estas eu ainda tinha. E tinha um daqueles lápis com logotipo que fluem como leite na FGV.

A máquina acima é uma impressora em 3D que pode fabricar objetos de plástico, cerâmica ou metal conforme comandada por um computador. Várias pessoas já construiram uma Darwin (a versão atual da RepRap). Em breve, a máquina poderá fabricar a si mesma — a previsão é 2008.

And then everything we know goes out the window.

A única coisa que eu sei é que a economia pós-escassez será o teste definitivo da controvérsia Malthus-Ricardo e dos princípios da demanda efetiva/lei de Say.

RepRap will make plastic, ceramic, or metal parts, and is itself made from plastic parts, so it will be able to make copies of itself. It is a three-axis robot that moves several material extruders. These extruders produce fine filaments of their working material with a paste-like consistency. If RepRap were making a plastic cone, it would use its plastic extruder to lay down a quickly-hardening 0.5mm filament of molten plastic, drawing a filled-in disc. It would then raise the plastic extrusion head and draw the next layer (a smaller filled disc) on top of the first, repeating the process until it completed the cone. To make an inverted cone it would also lay down a support material under the overhanging parts. The support would be removed when the cone was complete. Conductors can be intermixed with the plastic to form electronic circuits - in 3D even! This process is called fused deposition modeling; machines that do this are called 3D printers, rapid prototypers, or fabbers. They are very useful. Unfortunately they are also very expensive - $20,000 US or more - and existing models don’t self-replicate. The RepRap build cost will be less than $400 US for the bought-in materials, all of which have been selected to be as widely available everywhere in the world as possible. Also, the RepRap software will work on all computer platforms for free. Complete open-source instructions and plans are published on this website for zero cost and available to everyone so, if you want to make one yourself, you can. We hope to announce self-replication in 2008.

I use last.fm, which means in effect I’m giving up large ammounts of privacy — the kind of music I listen to — for the sake of social networking (which in the end I don’t use at all) and fun stats. And that’s okay; at least the terms of service assure me that

We won’t pass your email address on to anyone, not even Lars Ulrich at gunpoint.

Sure, it also claims that

We reserve the right to sell or license pseudonymous listening data for commercial use, however we will never sell your personal data that can be traced back to a specific user. We may, for example, license our weekly charts for commercial use. This would not compromise any personal information.

But then today I started getting ads in hebrew characters in my Gmail. I don’t ever receive or send emails with hebrew characters, or in Hebrew, or related to Israel in any kind or form.

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As you can see, my Gmail is set to portuguese language, and except for automated newsletters most every email I receive or send is in portuguese. I’ve been intrigued for most of the day. Then, just fifteen minutes ago, a friend was complaining about an annoying message she had been sent on last.fm. I went there to check and saw this:

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As you can see clearly on the right it says “Link patrocinado”, which means “Sponsored link”. It’s not a feed I subscribe to.

Of course, just this morning I dusted off a CD I had received as a gift when I was a teenager and ripped it to iTunes. The title on the cover says “Hava Nagila and other Jewish Melodies”, but the CDDB-derived title was written in hebrew characters.

And then the two things clicked. What kind of sinister coincidence is this?