The Computational Beauty of Nature
Computer Explorations of Fractals, Chaos,
Complex Systems, and Adaptation

About the Book
  · title page
  · home*
  · cover artwork
  · jacket text
  · table of contents
  · the author*
  · ordering information
Book Contents
  · three themes
  · part synopses
  · selected excerpts
  · all figures from book
  · quotes from book
  · glossary from book
  · bibliography
  · slide show
Source Code
  · overview &
  · FAQ list*
  · download source code
  · java applets
  · news*
  · reviews & awards
  · errata
  · for educators
  · bibliography (BibTeX format)
  · other links
Glossary - E

[ A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z ]


Ecology     The study of the relationships and interactions between organisms and environments.

Ecosystem     A biological system consisting of many organisms from different species.

Edge of Chaos     The hypothesis that many natural systems tend toward dynamical behavior that borders static patterns and the chaotic regime.

Effector     The part of a classifier system that can translate messages into actions that can manipulate a system or an environment.

Eigenvalue     The change in length that occurs when the corresponding eigenvector is multiplied by its matrix.

Eigenvector     A unit length vector that retains its direction when multiplied to the matrix that it corresponds to. An (n * n) matrix can have as many as n unique eigenvectors, each of which will have its own eigenvalue.

Embedding     A method of taking a scalar time series and using delayed snapshots of the values at fixed time intervals in the past so that the dynamics of the underlying system can be observed as a function of the previously observed states.

Emergent     Refers to a property of a collection of simple subunits that comes about through the interactions of the subunits and is not a property of any single subunit. For example, the organization of an ant colony is said to ``emerge'' from the interactions of the lower-level behaviors of the ants, and not from any single ant. Usually, the emergent behavior is unanticipated and cannot be directly deduced from the lower-level behaviors. Complex systems are usually emergent.

Entropy     A measure of a system's degree of randomness or disorder.

Environment     If that which is under study is a system, then the rest of the world is the environment.

Equilibrium     A state of a system that, if not subjected to perturbation, will remain unchanged.

Ergodic     The property of a dynamical system such that all regions of a state space are visited with similar frequency and that all regions will be revisited (within a small proximity) if given enough time.

Euclidean     Pertaining to standard geometry, i.e., points, lines, planes, volumes, squares, cubes, triangles, etc.

Euler's Method     The simplest method of obtaining a numerical solution of a differential equation. There are many other numerical techniques that are more accurate; however, an analytical solution (i.e., a closed form of an integral) is always preferred but not always possible.

Evolution     A process operating on populations that involves variation among individuals, traits being inheritable, and a level of fitness for individuals that is a function of the possessed traits. Over relatively long periods of time, the distribution of inheritable traits will tend to reflect the fitness that the traits convey to the individual; thus, evolution acts as a filter that selects fitness-yielding traits over other traits.

Evolutionary Stable Strategy (ESS)     In game theory and biology, a strategy that, when possessed by an entire population, results in an equilibrium such that mutation of the strategy can never result in an improvement for an individual. Always Defect is an ESS, while Always Cooperate is not.

Excitatory     Refers to a neural synapse or weight that is positive such that activity in the source neuron encourages activity in the connected neuron; the opposite of inhibitory.

Experimentation     One process by which scientists attempt to understand nature. A phenomenon is observed and/or manipulated so that changes in the phenomenon's state can be seen. The resulting data can be used to derive new models of a process or to confirm an existing model. Experimentation is the complement of theorization. See also simulation.

Expert System     A special program that resembles a collection of ``if ... then'' rules. The rules usually represent knowledge contained by a domain expert (such as a physician adept at diagnosis) and can be used to simulate how a human expert would perform a task.

[ A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z ]

Copyright © Gary William Flake, 1998-2002. All Rights Reserved. Last modified: 30 Nov 2002