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II. Creative feedback
Creativity
involves the production of complex patterns from simple processes.
What is the least initial complexity required
to generate both simple patterns and bios?
Four main mathematical ideas have been
developed to characterize complex processes: steady states, oscillations, chaos, and noise.
The empirical studies reported in Section
I indicate a fifth type, which we call bios.
Empirically observed patterns serve as beacons
to guide the development of mathematical models for creativity.
Also, the different terms in the equations
must be possible to interpret in terms of actual
physical aspects of natural processes (figure
13). The quantic
nature of action points to discrete iterations; differential equations and calculus imply and require continuity. To
study creativity, one must consider processes rather than static patterns; thus we compute recursions with varying
parameters; we call them kinetic equations, as contrasted to standard dynamic recursions computed with a constant
parameter. Kinetic equations generate a single time series with a
succession of patterns (“mathematical
development”).
The simplest and most universal process, present in both matter and empty space, is flux. By flux we refer to the spontaneous, apparently random, erratic fluctuations observed at all levels of organization. The existence of flux is a necessary consequence of the uncertainty principle that, excluding certainty, excludes absolute rest. The simplest physical process is the formation and destruction of pairs of opposite virtual particles within the limits of the action quantum. This indicates the fundamental character of opposition.
Figure 13: Simple physical processes containing basic forms reproduced at all levels of organization.
In this light, the idea of system’s boundaries needs to be reformulated. Space separates one solar system from another. Personal systems, such as families, have no boundary, constantly evolving through marriage, births and deaths. In organism, membranes are specialized structures that serve to channel communication. Systems do not have boundaries that separate them from others. Instead of boundaries, there are fields of interaction, and mutual feedback. Organisms, biological communities, ecological systems, continually interact with their environment. Each input contributes to determine the following action; in turn, the inputs received by a system are at least in part reactions to its previous action. This is feedback. Feedback is a universal and fundamental process in nature. Multiple and complex interactions of positive and negative feedback processes are involved in biological development --development is not simply the realization of a pre-existing blueprint. Feedback processes also obtain between persons and their interpersonal world, institutions and society. Feedback is an essential feature of natural processes, not a special process that obtains only in particular systems or organisms. Through its repetitive interactions with others, each system becomes both self-referential and co-creative.
Table 4. Mathematical developments generated by feedback At is the time series, f(At) is the function of At that produces change, and gt is the gain of this feedback.
* The logistic map, computed with a constant gain, has a fixed point. ** Ascending sequence of logons if the initial value A1 < terminal attractor h. Descending logons if A1t > h.
In natural systems, feedback is bipolar and diverse [François, 1997; Sabelli, in press]. Given the enormous diversity of natural environments, any action evokes some synergic responses and some antagonistic ones, one or the other predominating at different times. This bipolarity of natural feedback contrasts to purely positive and purely negative feedback mechanisms that have found such a wide range of applications in engineering. The creation of organization requires a combination of positive and negative feedback. If positive feedback processes would predominate, there will be no check to exponential growth in which plants become invading weeds, animals become pests, beliefs become self-fulfilling prophecies, and ideas are enthroned by bandwagon effects. Conversely, if negative feedback would predominate absolutely, there would be little change, and no evolution.
Mathematical feedback
Table 4 summarizes the results obtained with some of the models for coexisting positive and negative feedback. It includes logistic-like equations in which positive feedback predominates at low gain and negative feedback at high gain, process equations in which positive and negative changes occur at all gains, and a combination of the two (bipolar logistic equations). In all three classes, there can be feedback to the immediately preceding action At-1, to a past action At-k (delay equations), or to change in action At – At-1. Delay may be expected in feedback processes. The difference At – At-1 is the physical substrate of information. For instance, sensation is a function of a change in the stimulus rather than on the intensity of the stimulus. Recursions involving difference At – At-1 generate trifurcation and braids in their way to chaos and bios, instead of the usual cascade of bifurcations. Note in table 4 three routes to chaos and bios: (1) linear, (2) bifurcation, and (3) trifurcation.
Biotic development by bipolar feedback
Bipolar feedback is embodied
in recursions in which change is a trigonometric function of the preceding term [Kauffman and Sabelli, 1998; Sabelli
and Kauffman, 1999; Sabelli, 1999].
In the kinetic process equation At+1 = At + k * t * sin At the feedback gain g is a function of time ( gt = k * t), This recursion models action, opposition, and transformation, three universal components of natural processes. Iteration models the sequence of discrete and unidirectional actions; the sine function models the interaction of coexisting opposites; the gain g = k * t represents the intensity of these opposite interactions; and the sequence of actions At forms and transforms patterns. Each new action At+1 represents a continuation of the previous action At at time t, plus a change that results from positive (augmenting, synergistic) and negative (decreasing, antagonistic) responses to At depending on the sign of the sine function. This feedback is bipolar and diverse, spanning the range from plus to minus g through the continuity of the trigonometric function.
The amplitude and complexity of the patterns in the single time series generated by this bipolar feedback increases with the magnitude of the feedback gain (figure 15). For g < 2, the equation converges to an odd multiple of À (e.g. p for initial values between 0 and 2p). At g > 2, it generates symmetric opposites that diverge as the gain increases. Following the initial bifurcation, there is shift in each branch of the series that looks as a bifurcation in which only one outcome is visible (unifurcation). A cascade of period-doubling bifurcations generates 2N periods, followed by period 2 + chaos, and then by chaos with intrachaotic periodicities, among which period 6 and period 4 are prominent. When g < 4.604, At expands both positively and negatively, generating aperiodic biotic patterns resembling those observed with cardiac data. This is bios, an apparently erratic pattern of much larger magnitude than the preceding chaos. Process chaos is negatively autocorrelated, while bios is positively autocorrelated (Pearson’s coefficient for 1 lag +0.99); unpredictability obtains at the boundary between chaos and bios. Bios is terminates with a flight toward positive or negative infinity (infinitation) when the gain equals an even multiple of À (full rotation) and at few other critical values. As g increases further, new biotic series emerge, and further infinitations follow –a mathematical metaphor for death and renewal, essential features of living processes. Also, bios converges to bioperiods 2 when the gain equals odd multiples of À (half rotation inverting the sign of the sine function). Bios generates a new pair of opposites from which a new biotic phase emerges.
Figure 16: Distinguishing characteristics of deterministic patterns generated by bipolar feedback. Note the sensitivity to initial conditions of periodic patterns generated by bipolar feedback. Bold indicates series globally sensitive to initial conditions
Figure 17: Bios and infinitation show global sensitivity to initial conditions while chaos does not. Time series (N =90000) generated by the process equation at constant gain 4.1 (chaos), 4.61 (bios) and 2 p (infinitation). Initial Value: left = 1.000; right side 1.001, except for chaos, in which an initial value of 5 is used to highlight the difference between locally sensitive chaos and globally sensitive bios.
Figure 18: “Lifeforms” generated by a process equation computed with a gain that periodically increases and decreases (sinusoidal line). If the gain surpasses the threshold for bios, there is no complete reversibility to the initial value. In contrast, if the time series reaches only chaos, there is reversibility.
Figure 19: Time graph of the gain 0.0005 * t, the time series At (black lines) and the time series of the difference between consecutive terms of the series At - At-1(white lines) as the gain is increased by 0.0005 at each iteration.
Pointing to numerical counterparts of opposition, 2N and ÀN repeatedly appear as significant outcomes and gains --2 is the simplest opposition while 2p represents a full circle of opposites. At g = 2, the time series splits into period 2; at g = 22, period 12 develops; at g = 23, there is infinitation. Prominent periods are 6 = 2*3 and 4 during chaos, and period 2 and period 4 bioperiodicities during bios. À is the initial fixed point for initial values between 0 and 2À; even multiples of À separate basins of initial values that converge to odd multiples of À, and unifurcation occurs when At = 1.5 À and 0.5 À. Bios emerges when At ranges from 0 to 2p. As gain, À produces unifurcation; odd multiples of À produce period 2, and even multiples of À produce infinitation. These results point to an intriguing relation between unifurcation and bioperiodicity, and infinitation and convergence (which looks like an infinitation for vary small values of gain). Two abstracts the pairing of opposites; p describes the numerical relation between a pair of diametric opposites and the circumference formed by an infinite number of oppositions. We are tempted by no lesser men than Pythagoras, Galileo, Gödel and Jung to think that numbers represent form, just as they represent quantity and order.
When the previous action At serves as the feedback gain (figure 21), the time series generated by bipolar feedback evolves directly from a steady state to chaos. This illustrates a road to chaos other than bifurcation. Also, chaos does not develop when the cosine function replaces the sine in the feedback term. This is one example of the many asymmetries between these complementary opposites.
Figure 21: Process equations computed with gain = At. For the sine equation, chaos develops for almost all initial values, except for 1.5 p, 3.5p, etc. For the cosine equation, the series converges to 0.5 p for small initial values, and infinitates at critical initial values (e.g. between 4.9 and 6.9).
Symmetry and asymmetry
Opposition represents a measure of symmetry, but it does not exclude a degree of asymmetry. To investigate the dependence of creative processes on the relative magnitude of opposites, the process equation is modified to At+1 = At + g * (q + sinAt), where q allows one to introduce asymmetry in the bipolar feedback. Since the sine function varies between 1 and -1, total asymmetry obtains when q = 1 or q = -1. At high gain, biotic patterns occur when opposites are symmetric (q = 0), and steady states or divergence obtain when opposites are absolutely asymmetric (q = 1 or -1). Between these two extremes the biotic pattern acquires a trend, merging seamlessly with divergence. We call these trended biotic patterns “parabiotic” (figure 22). A small asymmetry reduces slightly the gain required to generate bios. In the same manner, at low gains, small asymmetry increases and large asymmetry decreases the complexity of pattern (figure 23). Thus, complexity increases with the intensity and symmetry of opposites (see figure 6), albeit there is nonlinearity (small asymmetry and moderate intensity are most creative). Kinetic symmetry is more creative than dynamic symmetry. Alternating a positive and a negative asymmetry (e.g. q is positive for odd iterations and negative for even iterations) generates complex patterns at lower gain than the symmetric recursion with q = 0 (figure 24). Figure 22: Biotic and parabiotic patterns generated by the process equation with gain 4.61.
Figure 23: Time series generated by the process equation at gain 2.8 (left) and 3.2 (right). In the symmetric case (extreme left, q = 0), period two is generated. As asymmetry increases (from 0 at the left to 1 at the right) we observe an increase and then a decrease in the complexity of pattern. Figure 24; Kinetic asymmetry is most creative. The entire time series generated by the process equation is here represented using a modified “logarithmic” scale. On top, the standard time series with q = 0. Bottom: the time series computed with q = 0.1 for odd iterations and –0.1 for even iterations. Note the development of period 2, chaos, bios, infinitation, and new bios, at much lower gain.
As biotic patterns obtain only when opposites are symmetric, the fact that cardiac beat series show a biotic pattern suggests that the opposite actions of accelerating and decelerating nerves and hormones that regulate cardiac intervals must then be largely symmetric --this is to be expected, as marked cardiac acceleration or deceleration can be lethal. Some economic processes show a parabiotic pattern that combines biological-like creativity with an asymmetric trend. Extreme trend leads to infinitation, a catastrophic acceleration that provides a mathematical metaphor for economic crises.
Delay and trifurcation
Figure 25: Top: Process equation computed with delay 1, 4, and 5, and gain 1. Bottom: Time series generated with increasing values of gain gt. The horizontal axis also corresponds to time. The biotic phase (not shown) is similar to that generated by the kinetic process equation.
Trifurcation and period 6 occur for feedback processes involving three terms of the series, such as with delay or with iteration of the difference between consecutive terms. The introduction of delay in the process equation generates period 6 (delay 1), a braid (delay 4), and bios (delay > 4) (figure 25 top). Note that there is no chaos. The kinetic process equation with delay (figure 25 bottom) At+1 = At + gt * sinAt-1 generates an initial steady state (p) that trifurcates (central value = p). A trifurcation is a bifurcation that conserves the initial fixed point. The trifurcation leads to chaos, and biotic patterns that resemble those observed in heartbeat interval series better than those generated by the process equation [Sabelli, 1999]. A prominent period 2 starts at g = p, separating two biotic phases.
Figure 26: Trifurcating equation showing an initial braid with a wall, a branching, chaos, and eventually leading to a biotic pattern that overlaps with period 6 (“colored bios”). In the trifurcation equation (figure 26) At+1 = At - At-1 + [k * t * sin(At)] six
strands of the trifurcation) form a beautiful braid that shows many complexities, including chaos, expansions, walls (sudden interruption of part of
the braid), and multifurcations. This braid eventually expands
into 6 biotic strands symmetrically distributed around 0, that approach and separate in a rhythmic fashion.
There
is no initial steady state.
Braiding
knots periodic patterns around each other.
While
a bifurcation cascade separates, a braid unites.
Logistic development
Computing the well-known logistic equation with an ever-increasing gain generates a time series that resembles the bifurcation diagram of the static logistic map, but lacking an initial fixed point (figure 27). Instead the time series grows exponentially up to the point of bifurcation. Logistic development has a great generality, and can be produced in several ways with bipolar feedback (figure 27), but in these cases the time series converge to an attractor rather than blow up. There are logistic-like development within the time series generated by the process equation (figure 15).
The logistic equation requires initial values between 0 and 1, gains between 0.45 and 4, and flights into infinity after chaos. In contrast, bipolar feedback is very flexible, allowing any value or sign for the initial value and the gain parameter, and generates biotic patterns beyond chaos. At is the conserved action, g is the energy, and the coefficient of g is the information or opposition. In the logistic equation, the opposites At and 1- At are inversely proportional, both ranging from 0 to 1. The logistic development is thus arrested at chaos. In the process equation, sin At is not inversely proportional to At; it is positive sine for At less than p and negative for At larger than p. When either At or 1- At are added as coefficients of the gain in the process equation, the development also is arrested in the chaotic phase and converges to a point attractor.
As in the case of the process equation, computations of the logistic equation that involve delay (figure 28) or the difference between successive terms (figure 29) generate trifurcations. These two equations do have an initial fixed point, and converge to attractors. .
Figure 29: Logistic-like equation in which the difference between consecutive terms is computed.
The coexistence of several
types of feedback that as may be expected to occur in actual processes.
The bipolar logistic equation (figure 30) At+1 = At + [At * k * t * sin(At)] generates a sequence of logistic like developments separated by shifts –it generates multiple “levels of organization”. For initial values between 0 and 2À, the recursion converges to À, and then bifurcates repeatedly and develops a chaotic pattern interspersed with periodicities. This sequence of patterns is similar to logistic development, but as the gain is increased, the series converges asymptotically to a point attractor instead of exploding. Whereas the logistic equation requires initial values between 0 and 1, the bipolar logistic allows any initial value. With low initial values, the series converges towards, but never reaches, zero. Initial values between even multiples of À converge to the included odd multiple of À, then generate the same sequence of patterns as the logistic equation, and terminate by converging to the next lower odd multiple of À. In this way one obtains a cascade of logistic-like developments (steady state, bifurcation cascade, chaos) that we shall call “logons”. If the initial value is sufficiently high, there is an initial biotic phase.
Figure 30: A bipolar logistic equation.
Other creative patterns
Figure 31: Left Firing pattern. Right: overlap of firing and bios. In addition to bios, bipolar feedback generates other patterns that display complexes, novelty, diversification, nonrandom complexity, and complex embedding plots. One of them, that we call “firing” (figure 31, left)by analogy to the firing of impulses by nerve cells, can be generated in many manners. A process equation in which the gain varies rapidly in a sinusoidal fashion illustrates that bios and firing can overlap in the same series (figure 31 right).
Mutual feedback and system synthesis
Figure 33: Mutual feedback with delay. Top panel shows the complex braid generated by one time series At, and the simpler increase in the other series Bt until it reaches the biotic phase. The lower diagram shows At in greater detail. Note that its initial pattern combines chaos with period 8. Sequential organization
Sequences of processes may also be expected to be common in systems. Sequences are creative processes that can generate complex patterns from simple origins, as illustrated by the cascade of equations in figure 34. The output of one feedback system generates the gain for the following system. In contrast, a circuit involving a number of feedback processes in which the gain of the first one is determined by the output of a later member in the system such as At+1 = At + Et *sin(At), Bt+1 = Bt +At *sin(Bt), Ct+1 = Ct +Bt *sin(Ct), Dt+1 = Dt +Ct *sin(Dt), and Et+1 = Et +Dt *sin(Et), generates a stable chaotic attractor.
Figure 34: A cascade of process equations: At+1 = At + Et *sin(At), Bt+1 = Bt +At *sin(Bt), Ct+1 = Ct +Bt *sin(Ct), and Dt+1 = Dt +Ct *sin(Dt). Note firing pattern in Bt
Arithmetic recursions
The models discussed above demonstrate at least three different roads to chaos and bios: growth, bifurcation, and trifurcation. Growth, bifurcation and trifurcation can be generated simple arithmetic recursions. The simplicity of arithmetic points to its fundamental nature. Gödel’s theorem implies that no simpler logic can account for arithmetic. The physical world is constituted by quantities (energy, time, information, matter). Action is a linear quantity; opposition is a two-dimensional pairing; organization is a topological form in a space of 3 or more dimensions (e.g. sphere, torus, etc).
Quantities add and subtract. The recursion of these simple operations generates growth, bifurcation, and trifurcation. Adding recursively consecutive members of a series At+1 = At-1 + At generates the well known Fibonacci series, that grows exponentially, and also generates spiral forms. Whereas addition is commutative i.e. symmetric, subtraction displays the asymmetry of order: A - B is not equal to B – A, and hence there are two different recursions. The series generated by the recursion At+1 =At-1 - At grows exponentially in both the positive and negative direction --difference generates opposition. This bipolar growth models, exemplifies and perhaps even explains enantiodromia, meaning “race of opposites”, postulated by process theorists since Heraclitus, as a fundamental form of nature.
The opposite equation At+1 = At - At-1 generates a period 6 composed of three pairs of opposite (positive and negative) numbers (figure 35). The algebraic structure of this period 6 resembles the relation between primary and secondary visual colors: there are three primary colors, such that the sum of two complementary opposites produces an identity element, and the sum of two primaries equals the complement of the third (figure 36). For instance, the complementary opposite of red is green, which is formed by mixing blue and yellow.
St+1 = St + k * Ctand Ct+1 = Ct – k * St generates a circle or an expanding spiral (figure 37), forms that, together with the linear addition implicit in action, generates the bipolar feedback of the process equation.
Figure 37: Addition and subtraction generate the sinusoidal forms used by the process equation to embody bipolar feedback at a constant or increasing gain.
In summary, these mathematical experiments lead us to the following conclusions and hypotheses:
[1] This is not intended as a theory of color vision. The term color is used in physics to refer to a property of quarks. In the same manner, the term color is used here in an abstract sense, as a metaphor to indicate a type of organization.
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