Sunday, June 29, 2008

Physics Part IV

I've added a new section on charge to my physics charts. It shows, for example, that magnetic flux is analogous to viscosity, but with charge in place of mass.

seconds^-2change in magnetic fluxchange in current
seconds^-1magnetic fluxcurrentmagnetic pole strength
linear charge densitychargeelectric dipole moment

seconds^-3areal power losslinear power losspower
seconds^-2surface tensionforceenergy
seconds^-1(dynamic) viscositymass transport ratemomentumaction
linear densitymassfirst mass momentmoment of inertia

seconds^-3jerkarea per second^3
seconds^-2angular acceleration / frequency driftaccelerationarea per second per second
seconds^-1hertz (units per second)velocitykinematic viscosity

Sunday, June 22, 2008

Rock Balancing

From Rock On. For other rock stackers, Bill has a blog.

Friday, June 20, 2008

A Little Humor

If you could be any kind of Philosopher, what kind would you choose? I'd like to be a Solipsist, but maybe that's just me.

Saturday, June 14, 2008

Another Chapter

"As every individual, therefore, endeavors as much he can both to employ his capital in the support of domestic industry, and so to direct that industry that its produce may be of the greatest value; every individual necessarily labors to render the annual revenue of the society as great as he can. He generally, indeed, neither intends to promote the public interest, nor knows how much he is promoting it. By preferring the support of domestic to that of foreign industry, he intends only his own security; and by directing that industry in such a manner as its produce may be of the greatest value, he intends only his own gain, and he is in this, as in many other cases, led by an invisible hand to promote an end which was no part of his intention. Nor is it always the worse for the society that it was not part of it. By pursuing his own interest he frequently promotes that of the society more effectually than when he really intends to promote it." (The Wealth of Nations)

Adam Smith realized that markets were capable of coming up with answers to questions that no human had the ability to solve. It was as if the system itself were exhibiting intelligent behavior. This is what he referred to in 1776 as “the Invisible Hand.” Today, scientists would call it emergent behavior in a complex adaptive system. But this behavior posed a problem—how did it happen that the world would be arranged in such a way that individuals seeking their own ends should happen to lead to such a happy state? For Smith, the answer was clear: God designed it that way. Leaving aside the theological question, however, what he proposed was perhaps the first realization of the idea of a creative rational mechanism: a designer (in this case God, but without necessarily using superhuman intellectual ability) could create a system that was capable of coming up with rational and creative decisions through an arrangement of many components, each following simple rules.
Darwin proposed a similar idea: God designed and set in motion a system of comprehensible laws that brought about new species creatively. In The Origin of Species he spoke of this creative action metaphorically, in personified terms:

[Nature] cares not for mere external appearance; she may be said to scrutinise with a severe eye, every nerve, vessel & muscle; every habit, instinct, shade of constitution,—the whole machinery of the organisation. There will be here no caprice, no favouring: the good will be preserved & the bad rigidly destroyed.… Can we wonder then, that nature's productions bear the stamp of a far higher perfection than man's product by artificial selection. With nature the most gradual, steady, unerring, deep-sighted selection,—perfect adaption [sic] to the conditions of existence.… (Darwin 1856, in Stauffer 1974, 224–25)

The conclusion of The Origin of Species also deals with this theme:

To my mind it accords better with what we know of the laws impressed on matter by the Creator, that the production and extinction of the past and present inhabitants of the world should have been due to secondary causes, like those determining the birth and death of the individual…
And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection.
It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us… Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.

Like Adam Smith, Darwin had proposed a system of enumerated laws that once having been laid down are capable of generating entirely new forms on their own. Darwin’s mechanism to explain how gradual change in life over time was able to come about had a profound effect on thinkers of the time. The Origin of Species was published in 1856, and by the next year Samuel Butler published Darwin among the Machines, which he later elaborated into a section of the Utopian novel Erewhon. One of the first works of science fiction, it proposes the idea that evolution need not be restricted to the animal kingdom, but could be put to use in developing technology that would be able to emulate human abilities, and even surpass them. In the long selections that follow, Butler addresses the possibility of machine consciousness, senses, language, reproduction, and evolution.

There was a time, when the earth was to all appearance utterly destitute both of animal and vegetable life, and when according to the opinion of our best philosophers it was simply a hot round ball with a crust gradually cooling. Now if a human being had existed while the earth was in this state … would he not have pronounced it impossible that creatures possessed of anything like consciousness should be evolved from the seeming cinder which he was beholding… Yet in the course of time consciousness came. Is it not possible then that there may be even yet new channels dug out for consciousness, though we can detect no signs of them at present?
Consciousness, in anything like the present acceptation of the term, having been once a new thing… why may not there arise some new phase of mind which shall be as different from all present known phases, as the mind of animals is from that of vegetables?
"It would be absurd to attempt to define such a mental state (or whatever it may be called), inasmuch as it must be something so foreign to man that his experience can give him no help towards conceiving its nature; but surely when we reflect upon the manifold phases of life and consciousness which have been evolved already, it would be rash to say that no others can be developed, and that animal life is the end of all things. There was a time when fire was the end of all things: another when rocks and water were so…"
"There is no security…against the ultimate development of mechanical consciousness, in the fact of machines possessing little consciousness now. A mollusc has not much consciousness. Reflect upon the extraordinary advance which machines have made during the last few hundred years, and note how slowly the animal and vegetable kingdoms are advancing. The more highly organized machines are creatures not so much of yesterday, as of the last five minutes, so to speak, in comparison with past time. Assume for the sake of argument that conscious beings have existed for some twenty million years: see what strides machines have made in the last thousand! May not the world last twenty million years longer? If so, what will they not in the end become?...
"But who can say that the vapour engine has not a kind of consciousness? Where does consciousness begin, and where end? Who can draw the line? Who can draw any line? Is not everything interwoven with everything? Is not machinery linked with animal life in an infinite variety of ways? The shell of a hen's egg is made of a delicate white ware and is a machine as much as an egg-cup is: the shell is a device for holding the egg, as much as the egg-cup for holding the shell: both are phases of the same function…
"There is a kind of plant that eats organic food with its flowers: when a fly settles upon the blossom, the petals close upon it and hold it fast till the plant has absorbed the insect into its system; but they will close on nothing but what is good to eat; of a drop of rain or a piece of stick they will take no notice. Curious! that so unconscious a thing should have such a keen eye to its own interest. If this is unconsciousness, where is the use of consciousness?
"Shall we say that the plant does not know what it is doing merely because it has no eyes, or ears, or brains? If we say that it acts mechanically, and mechanically only, shall we not be forced to admit that sundry other and apparently very deliberate actions are also mechanical?...
…the answer would seem to lie in an inquiry whether every sensation is not chemical and mechanical in its operation? whether those things which we deem most purely spiritual are anything but disturbances of equilibrium in an infinite series of levers, beginning with those that are too small for microscopic detection, and going up to the human arm and the appliances which it makes use of? Whether there be not a molecular action of thought, whence a dynamical theory of the passions shall be deducible? Whether strictly speaking we should not ask what kind of levers a man is made of rather than what is his temperament? How are they balanced? How much of such and such will it take to weigh them down so as to make him do so and so?..."

Butler’s position today would be called functionalism. It is the argument that systems that behave in ways similar to conscious minds are themselves conscious. Notice the words “where is the use of consciousness?” He is not particularly concerned with the problem of subjective perception, as long as the machine can act like a conscious being, responding appropriately to stimuli. In his day this was such a radical position that the whole chapter was laughed off as a satire of Darwin.
The next section takes William Paley’s argument for intelligent design and turns it on its head. The “Watchmaker Argument” was not original to Paley; there are references as far back as Cicero. But his version was well known at the time. Butler contends that the watch itself has undergone evolution of a sort, involving artificial rather than natural selection. From his other works, it is clear that Butler is less interested in the mechanism causing evolution than the fact of information transfer from parent to child. His understanding of this as a kind of “unconscious memory” is the basis behind DNA computing. He also notes the tendency towards miniaturization of computing components.

The present machines are to the future as the early Saurians to man. The largest of them will probably greatly diminish in size. Some of the lowest vertebrate attained a much greater bulk than has descended to their more highly organised living representatives, and in like manner a diminution in the size of machines has often attended their development and progress.
"Take the watch, for example; examine its beautiful structure; observe the intelligent play of the minute members which compose it: yet this little creature is but a development of the cumbrous clocks that preceded it; it is no deterioration from them. A day may come when clocks, which certainly at the present time are not diminishing in bulk, will be superseded owing to the universal use of watches, in which case they will become as extinct as ichthyosauri, while the watch, whose tendency has for some years been to decrease in size rather than the contrary, will remain the only existing type of an extinct race.
"… I fear none of the existing machines; what I fear is the extraordinary rapidity with which they are becoming something very different to what they are at present…

Butler uses the whistle of a train as an example of machine communication. He sees the system of train operator + train as a unit, where the functions of the train operator, already constrained to act in set ways to certain signals, will gradually be replaced by machines of increasingly “delicate construction.”

"As yet the machines receive their impressions through the agency of man's senses: one travelling machine calls to another in a shrill accent of alarm and the other instantly retires; but it is through the ears of the driver that the voice of the one has acted upon the other… There was a time when it must have seemed highly improbable that machines should learn to make their wants known by sound, even through the ears of man; may we not conceive, then, that a day will come when those ears will be no longer needed, and the hearing will be done by the delicacy of the machine's own construction?—when its language shall have been developed from the cry of animals to a speech as intricate as our own?
"… Take man's vaunted power of calculation. Have we not engines which can do all manner of sums more quickly and correctly than we can?... In fact, wherever precision is required man flies to the machine at once, as far preferable to himself. Our sum-engines never drop a figure, nor our looms a stitch... This is the green tree; what then shall be done in the dry?...

The analogy of a group of people with a living body shows up in the writings of Paul in the New Testament and in Hobbe’s Leviathan. Here it is used as an argument that a system of disconnected parts can come together to act in many ways like a living creature.

"It is said by some that our blood is composed of infinite living agents which go up and down the highways and byways of our bodies as people in the streets of a city. When we look down from a high place upon crowded thoroughfares, is it possible not to think of corpuscles of blood travelling through veins and nourishing the heart of the town? No mention shall be made of sewers, nor of the hidden nerves which serve to communicate sensations from one part of the town's body to another; nor of the yawning jaws of the railway stations, whereby the circulation is carried directly into the heart,—which receive the venous lines, and disgorge the arterial, with an eternal pulse of people. And the sleep of the town, how life-like! with its change in the circulation…"
…Are we not ourselves creating our successors in the supremacy of the earth? Daily adding to the beauty and delicacy of their organisation, daily giving them greater skill and supplying more and more of that self-regulating self-acting power which will be better than any intellect?...

The idea of a machine able to assemble copies of itself would later occur to von Neumann, and in Drexler's dream of nanotech assemblers. But Butler takes a different tack: the fact of machines assembling machines in a factory is already a form of reproduction. The place of people in the factory is shrugged off as a kind of symbiosis.

"Surely if a machine is able to reproduce another machine systematically, we may say that it has a reproductive system. What is a reproductive system, if it be not a system for reproduction? And how few of the machines are there which have not been produced systematically by other machines? But it is man that makes them do so. Yes; but is it not insects that make many of the plants reproductive, and would not whole families of plants die out if their fertilisation was not effected by a class of agents utterly foreign to themselves? Does any one say that the red clover has no reproductive system because the humble bee (and the humble bee only) must aid and abet it before it can reproduce?...
"It is possible that the system when developed may be in many cases a vicarious thing. Certain classes of machines may be alone fertile, while the rest discharge other functions in the mechanical system, just as the great majority of ants and bees have nothing to do with the continuation of their species, but get food and store it, without thought of breeding… Machines can within certain limits beget machines of any class, no matter how different to themselves. Every class of machines will probably have its special mechanical breeders, and all the higher ones will owe their existence to a large number of parents and not to two only.
"We are misled by considering any complicated machine as a single thing; in truth it is a city or society, each member of which was bred truly after its kind…. The truth is that each part of every vapour-engine is bred by its own special breeders, whose function it is to breed that part, and that only, while the combination of the parts into a whole forms another department of the mechanical reproductive system, which is at present exceedingly complex and difficult to see in its entirety.
"Complex now, but how much simpler and more intelligibly organised may it not become in another hundred thousand years? or in twenty thousand? For man at present believes that his interest lies in that direction; he spends an incalculable amount of labour and time and thought in making machines breed always better and better; he has already succeeded in effecting much that at one time appeared impossible, and there seem no limits to the results of accumulated improvements if they are allowed to descend with modification from generation to generation. It must always be remembered that man's body is what it is through having been moulded into its present shape by the chances and changes of many millions of years, but that his organisation never advanced with anything like the rapidity with which that of the machines is advancing…"

Finally he comes to artificial intelligence. He argues that free will is an illusion, that our own actions are determined based on our previous experiences and current stimulus. He acknowledges that complex systems are sensitive to initial conditions.

"But I have heard it said, 'granted that this is so, and that the vapour-engine has a strength of its own, surely no one will say that it has a will of its own?' Alas! if we look more closely, we shall find that this does not make against the supposition that the vapour-engine is one of the germs of a new phase of life. What is there in this whole world, or in the worlds beyond it, which has a will of its own? The Unknown and Unknowable only!
… the difference between the life of a man and that of a machine is one rather of degree than of kind, though differences in kind are not wanting. An animal has more provision for emergency than a machine… For how many emergencies is an oyster adapted? For as many as are likely to happen to it, and no more. So are the machines; and so is man himself. The list of casualties that daily occur to man through his want of adaptability is probably as great as that occurring to the machines; and every day gives them some greater provision for the unforeseen. Let any one examine the wonderful self-regulating and self-adjusting contrivances which are now incorporated with the vapour-engine, let him watch the way in which it supplies itself with oil; in which it indicates its wants to those who tend it; in which, by the governor, it regulates its application of its own strength; let him look at that store-house of inertia and momentum the fly-wheel, or at the buffers on a railway carriage; let him see how those improvements are being selected for perpetuity which contain provision against the emergencies that may arise to harass the machines, and then let him think of a hundred thousand years, and the accumulated progress which they will bring.

This last idea, the governor that regulates inertia, was the original example of cybernetics, the study of self-regulating systems which would eventually become synonomous with artificial intelligence. (From cybernetics we derive terms such as cyberspace.) Darwin’s collaborator Alfred Wallace wrote in 1858:

We have also here an acting cause to account for that balance so often observed in nature,—a deficiency in one set of organs always being compensated by an increased development of some others—powerful wings accompanying weak feet, or great velocity making up for the absence of defensive weapons; for it has been shown that all varieties in which an unbalanced deficiency occurred could not long continue their existence. The action of this principle is exactly like that of the centrifugal governor of the steam engine, which checks and corrects any irregularities almost before they become evident; and in like manner no unbalanced deficiency in the animal kingdom can ever reach any conspicuous magnitude, because it would make itself felt at the very first step, by rendering existence difficult and extinction almost sure soon to follow. (“On the Tendency of Varieties to Depart Indefinitely From the Original Type,” 1858)

A case can be made that it was this advancement in self-observing, self-modifying machines that inspired the concept of natural evolution, rather than the other way around. In reality, of course, the ideas in biology and mechanics formed a beneficial feedback loop.
Stuart Hoffmann, among others, has pointed out what evolution and the development of technology share that is lacking from other systems that we judge to be complex: the possibility space cannot be constrained beforehand. Evolution is often referred to as exploring a space of possibilities, finding local maxima. But evolution is able to expand its own space of possibilities, making thins possible that were previously impossible. Perhaps the only constraining space is the space of configurations of subatomic particles.
(This potential is often ignored in evolutionary algorithms. In many cases, a “genome” is defined as a vector of binary or real-valued numbers, each of which controls some parameter of a possibility space. For example, one value might control speed, another turning radius, another frequency of making turns, and so forth. But finding optimal values for any preset list of parameters can be more quickly accomplished by other algorithms than evolution.)
Art shares this open possibility space. New works of art, to be understood and valued as art, must build on an existing tradition or react to it. But there is no limit to the ways this building can happen, except what someone finds interesting or beautiful.
A creative machine would share this ability to expand into a limitless possibility space. However, any evolutionary algorithm needs an evaluation function. For life, this is survival until reproduction can occur. For art, it is the criteria of interest or beauty. How would we implement this criterion into a machine? We could program it or train it on what we had already found beautiful, but this would only allow it to recombine things that had been found beautiful in the past. Somehow, we would need to give it the ability to see for itself that something novel is interesting. There has, to date, been remarkably little work on how to achieve this.
Many creative evolution programs use a human in the loop to perform the evaluation of possibilities, choosing variations that are preferred. In this case, the computer is clearly a tool being used by the artist doing the choosing, rather than the machine itself acting as an artist.

Thursday, June 12, 2008

Communicating in Code

Every year, thousands of computer science papers are published. Many of these papers describe an algorithm or a program that the author has written, showing how the author's approach is better than previous solutions to the problem. The papers are amost invariably written in English (a universal language in the subject) and contain mathematical notation (another universal language.) All of this is useful. It distributes knowledge to other researchers and leads to development. But strangely, most of these papers contain no source code. Sometimes there is a small snippet of pseudocode illustrating the central innovation. Often, even that is missing. It seems bizarre, as if a journal of art criticism contained no illustrations, or a book on how to cook contained no recipes. Why are we in this absurd situation?

1. Computer scientists, not software architects. The usual response is that the author is a scientist studying ideas, rather than an engineer building something meant for serious use. But the scientist has invariably already built something to test the idea. It's not like particle physics, where theorists have ideas that can't be put into practice because of the expense. (Ideas like these are usually dismissed as unworthy of a paper in computer science. It's a cultural thing.) It could easily be distributed, but isn't. Perhaps some of the authors really have no interest in seeing source code from others, and assume everyone feels the same way. This way of thinking is so alien to me I have trouble even considering the point of view. A mathematical formula is so compact in its notation that it takes enormous effort to unpack. And the formulas contained in papers rarely define all their variables, expecting the reader to pick up the meaning of some of the variables from experience or context.

2. Lack of a universal language.There is no standard programming language. Perhaps a dozen languages are currently widely used. Where source code is available for the kind of programs I am interested in, it is invariably in one of the following languages: C, C++, C#, Java, Matlab, or Lisp. However, all of these (with the exception of Lisp) are so similar in structure that any programmer who can understand code in one of the languages can understand code in any of the others. It may be uncomfortable to work in, but more of an annoyance than a roadblock.

3. Lack of universal libraries. Most programs use other libraries in order to run. These libraries can be difficult to install and use, and often have unwritten assumptions built into them. The researcher could easily share the original code, but sharing the libraries needed to run it and where to get them seems like a huge burden.This is true, but why is it true? Why don't we have a widely shared set of libraries to take care of all the previously solved computer science problems? The answer is because no one is making the effort to create useful code and share it. If this were the priority rather than just the papers, the problem would quickly take care of itself. It's partly a chicken-and-egg problem.

4. The program wasn't written to be understood. Often computer scientists are ashamed of their code, and don't want it to be made public. They know that it is sketchy, inefficient, poorly documented, bug-ridden, and requires arcane rituals to get to work at all. It's more like a messy research notebook than a paper. This is all true. But why don't they rewrite the code for the paper? It wouldn't take much more work than writing the paper itself. The answer is purely cultural: a paper confers prestige, raises awareness, gets you into conferences, and so forth. Beautiful code goes largely unappreciated. It is this cultural aspect I really want to see changed. It seems to me that the right language to express computer science ideas in is (well designed and well documented) code. It can sacrifice some efficiency for the sake of clarity. Learning to communicate in this way should be taught as part of every computer science class.I'm not advocating strict obediedence to some standard. I'm advocating teaching literacy in programming, the ability to read and write code whose purpose is completely transparent and as easy to read as prose text. Perhaps the language, tools, and libraries to do this don't really exist yet. But in the future, people will look back in wonder that we were able to get anything done at all. Imagine how useful it would be to be able to immediately compare a new approach to any existing approach. Imagine how much progress could be made if all the existing ideas were available to be used without significant effort as building blocks of a new algorithm.


Wednesday, June 11, 2008

Book chapter

This is a draft of another chapter for my book. The working title of the book is Artificial Creativity: The Thousand Year Quest to Build a Creative Machine.


In 1817, Sir David Brewster patented the kaleidoscope. Others had noticed the effect of two mirrors meeting at an angle before, as recounted in this selection from a 1818 article in The Edinburgh Magazine and Literary Miscellany:

The repetition and reversion of images in a glass is noticed in the Masfiti Naturalis of Baptista Porta, a Neapolitan nobleman, who flourished about the latter part of the sixteenth century, and was distinguished for his zeal in promoting philosophical pursuits…
In the Ars Magna LucĂ­s et Umbra of Kircher, printed in 1646, we have an account of the same circumstance, and also of the repetition of the sectors round the centre of the circle:
“A wonderful property,” says he,” and one which has not, as far as I know, been observed by any one, is exhibited with two specula, so constructed as to open and shut like a book; and placed on any plane in which you have described a semicircle divided into its degrees. For, if the point in which the specula meet be placed in the centre of the semicircle, so that the side of each speculum shall stand upon the diameter, the image of an object will only be seen once, and two objects will appear, one without the specula, the true one,—and one within, the image. But if the sides be placed at an angle of 120°, you will see the image of the object within the specula twice, that is, along with the real image, three objects But if the specula intercept an angle of 90°, you will see the circle divided into four parts, and four objects; in the same manner, at an angle of 60°, you will see a hexagon with six objects.”
He then applies the principle to some curious contrivances which, by his own account, filled his spectators with astonishment. With one candle he shows how to make a complete chandelier. “With angles of 120°, 72°, and 45°, you will see,” says he, “with no less delight than adimration, a chandelier with three, with five, and with eight branches.”

When Brewster showed his prototype kaleidoscope to manufacturers of optical instruments, pirate copies began cropping up all over the London and soon spread around the world:

You can form no conception of the effect which the instrument excited in London; all that you have heard falls infinitely short of the reality. No book and no instrument in the memory of man ever produced such a singular effect. They are exhibited publicly on the streets for a penny, and I had the pleasure of paying this sum yesterday; these are about two feet long and a foot wide. Infants are seen carrying them in their hands, the coachmen on their boxes are busy using them, and thousands of poor people make their bread by making and selling them. (letter from Brewster to his wife, May 1818)

The kaleidoscope allowed the viewer to enter into a virtual world, filled with bright colors and concealed symmetries. If it was a scientific instrument (as the name implied), it was an instrument of some faerie science, a science of beauty. It partook of the potential of mirrors to create other worlds, to open up new infinite spaces. The forms were reminiscent of magical mandalas, and viewers often compared the hypnotic effect of looking through a shifting kaleidoscope to that of listening to music.

IF we examine the various objects of art which have exercised the skill and ingenuity of man, we shall find that they derive all their beauty from the symmetry of their form, and that one work of art excels another in proportion as it exhibits a more perfect development of this principle of beauty. Even the forms of animal, vegetable, and mineral bodies, derive their beauty from the same source... (Brewster chapter 20)

Brewster’s conception of beauty was grounded in neoclassicism. Symmetry and geometric order were key ideas in this. Beyond that, he assumed that a science of beauty was possible, that universal principles of beauty could be discovered. In The Kaleidoscope (a book on the optical theory behind the construction of his invention) he gives a theory of color harmony and repeatedly emphasizes the importance of carefully constructed devices that don’t allow the slightest imperfection in symmetry.
He conceived of the kaleidoscope as a labor saving device for artists, an automation of part of the creative process:

When we consider, that in this busy island thousands of individuals are wholly occupied with the composition of symmetrical designs, and that there is scarcely any profession into which these designs do not enter as a necessary part, so as to employ a portion of the time of every artist, we shall not hesitate in admitting, that an instrument must have no small degree of utility which abridges the labour of so many individuals. If we reflect further on the nature of the designs which are thus composed, and on the methods which must be employed in their composition, the Kaleidoscope will assume the character of the highest class of machinery, which improves at the same time that it abridges the exertions of individuals. There are few machines, indeed, which rise higher above the operations of human skill. It will create, in a single hour, what a thousand artists could not invent in the course of a year; and while it works with such unexampled rapidity, it works also with a corresponding beauty and precision. (Brewster chapter 20)

Things did not turn out quite as Brewster expected. Our use of machines to automate work previously done by artists has modified our concept of beauty. What used to take a great deal of skill and time could be done immediately and without effort by a mechanical process. This led to society valuing designs of rigid perfect symmetry less. A similar effect occurred with the invention of photography. Because of the ease of obtaining a perfectly accurate likeness, abstract and nonrepresentational art became more highly valued by the art world.

The kaleidoscope is a prototype for many computer programs that attempt to generate new works of art. Each one follows the same pattern:
1. Hand-selected forms to be recombined. Brewster recommends buttons, bits of broken glass, a distant bonfire, dancers, etc... [pull more examples from his book]
2. Random or nearly random input. In the kaleidoscope, this comes from shaking the bits of glass.
3. Formal constraints. The kaleidoscope uses mirrors to impose symmetry.

For example, a Markov poetry generator takes a set of words (preselected for the intended effect, such as all words used in works by a given author) recombine them randomly, but imposing constraints of use frequency patterns. Fractal generators use slightly more sophisticated symmetry constraints on the randomness. Similar examples can be found for music, such as David Cope’s EMI program. [include example output from each of these]

While all of these hold some interest in the beginning, after a short time newly produced works fail to add anything new to the already formed impression. Instead of learning individual works, our brains pick up on the pattern that underlies all of the output. Although at first it seemed that the machine was being creative, it later becomes apparent that a store of creativity injected, as it were, during the creation of the program, has merely been allowed to leak out slowly.
In Zen and the Art of Motorcycle Maintenance, Pirsig identifies two kinds of beauty: classical beauty and romantic beauty. [quote from Z&AMM here] Both are evident in these kaleidoscopic machines: the hand selected elements are romantically beautiful, beautiful in how they present themselves to the senses. The formal constraints are classically beautiful in how they appeal to the intellect.
It is comparatively simple to set up a system of rules and generate new images. It is much more difficult to choose a set of rules that will produce images that are aesthetically pleasing. In order to do the latter, we need to have some theory of beauty or interest. The attempt to mechanize requires that we understand; but the attempt to understand beauty transforms it. There is essentially a paradox here: creativity must continually be pushing the boundaries of what is new. Simply being new is not enough, however; to be considered creative it must be both new and beautiful. Any static conception of beauty must quickly become inadequate.
The problem becomes, then, how to make a machine that grows in ability over time, that is not limited by the initial choices made by the author of the program. In the next chapter [about Charles Darwin and Samuel Butler] we’ll look at how scientist came to understand how the creation of new forms could arise from the action of natural laws and immediately began to apply the concept to the development of creative machines.