impedance.html

The Bicycle and the Transformer

Impedance and Impedance Matching

My thoughts on these subjects are often expressed as analogies or metaphors, and it is now time for the bicycle metaphor, an idea which has quite taken over my thinking of late.

In another section I mention a small gray cylinder, a matching transformer, for coupling a loudspeaker to the input of an audio amplifier. This is really just another version of the bicycle metaphor, although a more limited one since it is not a variable interface.

Among friends I have long talked about a more ideal interface to the internet. Among the qualities we attributed to this interface was an ability to match the user to the rest of the net in much the same was as the variable gearing of a 10-speed bicycle matches the muscles of the rider to the wheels.

The essential idea here is that an impedance-matching device can couple a person to something else (the wheels of a bicycle, an audio amplifier, the internet, or even just another person), so that energy (or negative entropy, or information-processing ability, or whatever) of the person is completely absorbed by that “something else”, with minimal losses.

Indeed almost all of engineering can be seen as the careful interfacing of one piece of equipment to another, and the essence of high-technology is the ability to do this interfacing with powerful mathematical tools.

The basic idea there goes back to my long stay in Ottawa, when among other things I wrote a specification for the human-factors-engineering task of the air traffic control system re-engineering project. I spent a lot of time trying to define just exactly what it was about computer screens, fonts, joysticks, switches, and so on that made them good or bad for the human operator.

Eventually I decided that this was basically an optimization problem, the problem of matching (for example) the energy requirements of the a toggle switch to the range of energies used by the operator — a switch should require enough force to flip it that the operator will not do so accidentally by brushing against it, but not too much — not so much as to pose any real problem. I actually wrote in some purposeful inefficiencies in to that spec, to accommodate the human need for changes of posture, and for a certain expenditure of muscle energy to avoid cramping and other hazards of life at a workstation.

I took my old XT computer to Ottawa with me, and spent most of hours at home busman’s-holiday style, working on my own software development ideas. There was of course a certain amount of leakage of my at-work play into my at-home work, and a some point I came up with the idea of a piece of software that would be coupled or matched to me and my peculiar strengths and weaknesses. The essence of a good piece of software would be the way in which it allowed my energies, or neg-entropies, or information-handling abilities to be constructively used with the minimum amount of difficulty or frustration, and some opportunity to stretch mental muscles.

Hence the bicycle metaphor, which is just the concept of impedance matching that I have talked about again and again: when travelling up hill (e.g. reading or writing something difficult), you need the ability to switch to a lower gear. When trying to speed on a straightaway (e.g. dumping a massive load of ill-digested ideas on one’s poor unsuspecting reader, typing a way at a great rate) you need to switch to a higher gear.

The same analogy could be made with automobiles, of course, but for the bicycle case you are the engine, and are therefore most sensitive to the uphills and downhills of life.

So, while in Ottawa I began a “great project”, sigh, to come to naught as so many of my projects do. I called this the “Great Tool” project, and it was intended to match my personal strengths and weaknesses to the tasks of writing and disseminating my ideas. The only result of this project was an outliner and text organizer thing (version 0.001) that I still use but seems less and less ideal every day.

Of course the real Great Tool for writing and disseminating one’s ideas is another person , and, as I have so often defined it, a very specific other person, one  who shares your interests but makes the opposite sort of errors, or has complementing strengths and weaknesses.  See my comments on Error Covariance for more about this.  (An example: one brief writing project I was involved with had two INTP personality types , and was therefore almost doomed from the start: we were great at the brainstorming, but terrible at the pragmatics of writing.)

But there is a point to all this rehashing of old hash, and that is a clearer and more correct statement of the impedance matching problem.

In some ways the bicycle metaphor is better than the small-gray-cylinder metaphor, since the selection of gears allows a choice of ratios for matching human energy to the wheels appropriately for different terrains. But in some ways the matching-transformer is a better model because it is much more clearly a device with a spectrum: it worked for a large part of audio-frequency range, say from 100 to 10000 cycles per second.

For electrical or electronic devices (or at least for analog devices, and especially for linear analog devices) the spectral response curve is not flat enough that we could say, as I did of the small-gray-cylinder, simply that it matched the 8-ohms of the loudspeaker to the several-hundred-thousand-ohms of the audio amplifier. For most (more or less linear) analog devices the characteristic properties cannot be given as just one pair of numbers (input and output impedance) but need a complete spectrum of numbers, one for each frequency. (Technically we need pairs of numbers, i.e. complex numbers, for each frequency).

If we take the number of numbers required to completely specify a (more-or-less-linear analog) device as a measure of its complexity, it follows that such devices can be arbitrarily complicated, as complicated as we are, for example. It would therefore not be unreasonable to demand to know the complex spectrum of a person. (I mean the spectrum as given by complex numbers, not the complicated spectrum, although surely the spectrum a person would be complicated as well.)   For more on this please see my page about Linearity .


Copyright © 1998 Douglas P. Wilson      



Copyright © 2009   Douglas Pardoe Wilson

Other relevant content:

New: Social Technology through Diagrams

New: Social Techs novel online

New: Social Technology Blog

New: Social Technology Wiki

Please see these web pages:

The main Social Technology page.

Find Compatibles , the key page, with the real solution to all other problems explained

Technological Fantasies , a page about future technology

Social Tech a page about Social Technology, technology for social purposes.  I think I was the first person to use this phrase on the Internet, quite a long time ago.


Roughly corresponding to these web pages are the following blogs :

Social Technology the main blog, hosted on this site, with posts imported from the following blogger.com blogs, which still exist and are useable.

Find Compatibles devoted to matching people with friends, lovers, jobs, places to live and so on, but doing so in ways that will actually work, using good math, good algorithms, good analysis.

Technological Fantasies devoted to future stuff, new ideas, things that might be invented or might happen, such as what is listed above and below.

Sex-Politics-Religion is a blog about these important topics, which I have been told should never be mentioned in polite conversation.  Alright that advice does seem a bit dated, but many people are still told not to bring up these subjects around the dinner table.

I believe I was the first person on the Internet to use the phrase Social Technology — years before the Web existed.

Those were the good old days, when the number of people using the net exceeed the amount of content on it, so that it was easy to start a discussion about such an upopular topic.  Now things are different.  There are so many web pages that the chances of anyone finding this page are low, even with good search engines like Google.   Oh, well.

By Social Technology I mean the technology for organizing and maintaining human society.  The example I had most firmly in mind is the subject of  Find Compatibles , what I consider to be the key page, the one with the real solution to all other problems explained.

As I explained on my early mailing lists and later webpages, I find that social technology has hardly improved at all over the years.   We still use representative democracy, exactly the same as it was used in the 18th century.  By contrast, horse and buggy transporation has been replaced by automobiles and airplanes, enormous changes.

In the picture below you will see some 18th century technology, such as the ox-plow in the middle of the picture.  How things have changed since then in agricultural technology.  But we still use chance encounters, engagements and marriages to organize our home life and the raising of children.  

I claim that great advances in social technology are not only possible but inevitable.  I have written three novels about this, one preposterously long, 5000 pages, another merely very very long, 1500 pages.  The third is short enough at 340 pages to be published some day.  Maybe.  The topic is still not interesting to most people.   I will excerpt small parts of these novels on the web sometime, maybe even post the raw text for the larger two.


This site includes many pages dating from 1997 to 2008 which are quite out of date.  They are included here partly to show the development of these ideas and partly to cover things the newer pages do not.  There will be broken links where these pages referenced external sites.  I’ve tried to fix up or maiintain all internal links, but some will probably have been missed.   One may wish to look at an earlier version of this page , rather longer, and at an overview of most parts of what can be called a bigger project.

Type in this address to e-mail me.  The image is interesting.  See Status of Social Technology

Copyright © 2007, 2008, 2009, Douglas Pardoe Wilson

I have used a series of e-mail address over the years, each of which eventually became out of date because of a change of Internet services or became almost useless because of spam.  Eventually I stuck with a Yahoo address, but my inbox still fills up with spam and their spam filter still removes messages I wanted to see.  So I have switched to a new e-mail service.  Web spiders should not be able to find it, since it is hidden in a jpeg picture.   I have also made it difficult to reach me.  The picture is not a clickable link.  To send me e-mail you must want to do so badly enough to type this address in.  That is a nuisance, for which I do apologize, but I just don’t want a lot of mail from people who do not care about what I have to say.


Cross-References:

Finding Another Athlete to Train With

Information Retrieval

Technical Information

Work-In-Progress


Copyright © 2009   Douglas Pardoe Wilson

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