Impression of systems thinking about society
Systems science is an interdisciplinary field that studies the nature of systems—from simple to complex—in nature, society, cognition, engineering, technology and science itself. To systems scientists, the world can be understood as a system of systems. The field aims to develop interdisciplinary foundations that are applicable in a variety of areas, such as psychology, biology, medicine, communication, business management, engineering, and social sciences.
Systems science covers formal sciences such as complex systems, cybernetics, dynamical systems theory, information theory, linguistics or systems theory. It has applications in the field of the natural and social sciences and engineering, such as control theory, operations research, social systems theory, systems biology, system dynamics, human factors, systems ecology, systems engineering and systems psychology. Themes commonly stressed in system science are (a) holistic view, (b) interaction between a system and its embedding environment, and (c) complex (often subtle) trajectories of dynamic behavior that sometimes are stable (and thus reinforcing), while at various 'boundary conditions' can become wildly unstable (and thus destructive). Concerns about Earth-scale biosphere/geosphere dynamics is an example of the nature of problems to which systems science seeks to contribute meaningful insights.
An immune system is a collection of mechanisms within an organism that protects against infection by identifying and killing pathogens and tumor cells. It detects a wide variety of pathogens, such as viruses and parasitic worms and distinguishes them from the organism's normal cells and tissues. Detection is complicated as pathogens adapt and evolve new ways to successfully infect the host organism.
To survive this challenge, several mechanisms have evolved that recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess enzyme systems that protect against viral infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants, fish, reptiles, and insects. These mechanisms include antimicrobial peptides called defensins, pattern recognition receptors, and the complement system. More sophisticated mechanisms, however, developed relatively recently, with the evolution of vertebrates.
This image illustrates part of the Mandelbrot set fractal. The size of the JPEG file encoding the bitmap of this image is more than 17 kilobytes (approximately 140000 bits). The same file can be generated by a computer program much shorter than 140000 bits, however. Thus, the Kolmogorov complexity of the JPEG file encoding the bitmap is much less than 140000.
Selected systems scientist
W. Ross Ashby (September 6, 1903, London - November 15, 1972) was an English psychiatrist and a pioneer in cybernetics, the study of complex systems. His first name was never used, and generally, he was called 'Ross Ashby'.
Despite being widely influential within cybernetics, systems theory and, more recently, complex systems, he is not nearly as well known as many of the notable scientists his work influenced including Herbert A. Simon, Norbert Wiener, Ludwig von Bertalanffy, Stafford Beer and Stuart Kauffman.