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Self-Organizing Circuit Reinvents Radio
PortWineBoy writes "An evolutionary computer program that controls circuits connected to transistors is told to 'breed' an oscillator. Instead, it breeds a radio receiver which picks up oscillation produced by a nearby computer to achieve the desired result. It seems interesting to me but does it have any implications or applications? Any thoughts on how something like this could be used elsewhere?"
I remember reading about something like this earlier, where they had a circuit that modified itself (it was implemented on an FPGA) and it was supposed to figure out how to solve a mathematical problem. After it randomly came up with a "working circuit", the engineers couldn't debug it -- until they figured out the FPGA circuit as implemented was making use of stray RF signals to help solve the "problem"
You mean this article?
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For those of you who want to read that article (or at least one that describes what he's talking about), here it is:a l.jsp
http://www.newscientist.com/hottopics/ai/primordi
In a sense, the very thing that makes circuit evolution so potentially powerful is also its weakness -- it evolves to external conditions. In the same way that a hummingbird would be doomed if all the flowers that are shaped for its beak died out or changed their shape, so too are these circuits dependent on the environment in which they evolved. An ideal solution would be to allow these circuit boards to continue to evolve, so that when they are placed in new environments, they will be able to adapt to them.
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I can tell you from many painful experiences that the most common occurance when connecting transistors in an unintended manner is shorting the (low impedance) power supply with a forward biased P-N junction, or putting too much voltage accross a reverse biased P-N junction... either way leading to destruction of one of more parts. Let's presume they constrained the choices to prevent blown parts.
When nothing blows up, the two most common cases (when connecting high-gain amps) are unintentional oscillation and unintended pickup of stray signals. It takes good design practice and good implementation to avoid these (usually) undesirable results.
To say that it "Reinvents Radio" is crazy. Radio reception involves the concept of demodulation, where changes in the received signal are turned into the output and the "carrier" frequency is not. Simply receiving a signal is not radio, and any reasonable sense of the word in the context of transistor circuits. Extracting modulated changes to that signal is what radio is about. Even the simplest forms of radio, such as on/off keying (morse code, etc) involve translating bursts of the carrier into tones or some other indication to the user. The key concept is that the transmitter encodes information by modulating the transmitted signal, and the receiver recovers the information, not just the raw signal.
Usually, but not always, rolled up in the concept of "radio" is a tuning system that selects a very small band of the available spectrum for reception, and usually this tuning system can be controlled accurately to correspond to the know carrier frequency used by the transmitter. Certainly in its modern usage, the word "radio" reasonably also implies good selectivity of frequencies that are received.
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Having designed the things for a living, I can tell you oscillators are far more complex devices than their relative simplicity suggests. In fact the major problem with an oscillator design is to confine it's operation to the parameters specified. If care isn't taken they'll act as sensitive receivers, phaselocking on any extraneous signal that is harmonically close to it's fundamental frequency. Armstrong noticed this when he was developing the regenerative detector and used it to great effect, resulting in a one tube receiver that had the sensitivity of a five tube tuned amplifier receiver.
... random, depending on the starting value of x and the constant value of r. What really gets interesting is when one establishes a second equation and couples them together, ie. x'=rx(1-x-by') and y'=sy(1-y-cx'). Selecting values for b and c can result in oscillations that are very complex, regular patterns.
:)
The interesting part of the article was the fact they allowed the oscillator to design itself, not that it ended up being a receiver.
Someone else on here suggested life could have started the same way, and I suspect to a great extent he's right. Playing with chaotic oscillators is instructive, the population equation (or logistic equation), x'=rx(1-x), demonstrates all the different modes of oscillation an electonic oscillator can have. none, single mode, bimodal, quad, octal,
Science has found that living cells contain a myriad of chemical oscillators, coupled together in unknown ways, apparently regulating cell metabolism, gene switching and division. I wouldn't be at all surprised they find this oscillation is the key to life, evolution and everything.