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Posts tagged with douglas hofstadter

from “On Self-Referential Sentences” by Douglas Hofstadter, originally in Scientific American (January 1981), reprinted in Metamagical Themas (1985)
via crystilogic




For Ann (rising) by James Tenney

Never, ever listen to / watch this while on drugs. Or your brain might kill you.

I haven’t read Doug Hofstadter's latest book I Am A Strange Loop — but apparently one of the examples he gives of a stream / cycle / loop is: a sonic version of the optical-illusion-of-a-staircase-always-going-up-thing. It’s called a Shepard Tone and was invented in the 60’s.

Here’s what the Shepard tone looks like:

Here’s what it sounds like:

http://en.wikipedia.org/wiki/File:DescenteInfinie.ogg

Here’s the Editable Encyclopedia’s description:

The acoustical illusion can be constructed by creating a series of overlapping ascending or descending scales.

As a conceptual example of an ascending Shepard scale, the first tone could be an almost inaudible C4 (middle C) and a loud C5 (an octave higher). The next would be a slightly louder C#4 and a slightly quieter C#5; the next would be a still louder D4 and a still quieter D5. The two frequencies would be equally loud at the middle of the octave F#, and the eleventh tone would be a loud B4 and an almost inaudible B5 with the addition of an almost inaudible B3. The twelfth tone would then be the same as the first, and the cycle could continue indefinitely. (In other words, each tone consists of ten sine waves with frequencies separated by octaves; the intensity of each is a gaussian function of its separation in semitones from a peak frequency, which in the above example would be B4.)




I’ve explained group theory to fifth graders. People who haven’t tried it don’t realise the difference between explaining something to a group of a group of 8th graders, a group of 5th graders, a group of 2nd graders, or a group of college freshmen.

How did I do it? I used salt and pepper shakers. I talked about horsies and doggies. It may sound funny, but it’s actually just effective. Today’s mathematicians think that if something isn’t unreadable, then it can’t be serious, worthwhile, or good. But obfuscation doesn’t make something more valuable; just the opposite.

My advice is to write the opposite way the Bourbaki group does. Never write

when

will do.

—rough paraphrase of Doug Hofstadter




Moore’s three-dimensional law is a remarkable “epiphenomenon” … a statistical regularity that emerges from a swarm of unknown, mutually independent activities. In that sense, it resembles the “law” that says that each Labor Day weekend, about 450 automobile fatalities will occur in the United States.

This nationwide prediction can be made years in advance and will turn out quite accurate, despite the fact that the location and reason of each crash — each constituent microevent — are of course totally unpredictable.




What’s the difference between leaving carbon progeny behind you and silicon progeny behind you? … [W]hat makes you feel that a planet teeming with sexually created successors would constitute a more valid extension of ‘we’-ness than a planet teeming with our intellectually created successors? [robots / cyborgs / conscious machines / strong AI computers]

The question comes down to how we human beings feel comfortable using and extrapolating the term pronoun “we”. Were “we” once languageless squirrel-sized mammals? Did “we” then become primates? Did “we” discover that “we” could use tools? Did “we” begin speaking some 50,000 years ago? Were “we” at that time an entirely agrarian society? Did “we” start living in cities a few thousand years ago? Did “we” discover geometry, algebra, and calculus? Did “we” try out communism for a few decades? Will “we” someday cure cancer? Will “we” someday fly to Mars? … Will “we” migrate into immortal software?

Doug Hofstadter, in Perspectives on Natural and Artificial Evolution

The whole essay (ok, most of it):

grâce à Virgil

 

The story of the primates reminds me of my favourite short story from Cosmicomics. Italo Calvino shrinks the generations of evolution into manageable bites, so that qfwfq, a lizard in this story, has a great-uncle n’ba n’ga who’s still a fish.

Well, you can read it yourself:




The Goldberg Variations composed by J.S. Bach, played by D. Gould