definition of Wikipedia
Heinz von Foerster (born Heinz von Förster; November 13, 1911, Vienna – October 2, 2002, Pescadero, California) was an Austrian American scientist combining physics and philosophy. Together with Warren McCulloch, Norbert Wiener, John von Neumann, Lawrence J. Fogel, and others, Heinz von Foerster was an architect of cybernetics.
Von Foerster was born in 1911 in Vienna, Austria-Hungary, as Heinz von Förster. He studied physics at the Technical University of Vienna and at the University of Breslau, where in 1944 he received a Ph.D. in physics.
He moved to the USA in 1949, and worked at the University of Illinois at Urbana-Champaign, where he was a professor of electrical engineering from 1951 to 1975. From 1962 to 1975 he also was professor of biophysics and 1958–75 director of the Biological Computer Laboratory. Additionally, in 1956–57 and 1963–64 he was a Guggenheim-Fellow. From 1963 to 1965 he was president of the Wenner-Gren-Foundation for anthropological research.
He knew well and was in conversation with John von Neumann, Norbert Wiener, Humberto Maturana, Francisco Varela, Gordon Pask, Gregory Bateson, Lawrence J. Fogel and Margaret Mead, among many others. He influenced generations of students as a teacher and inclusive, enthusiastic collaborator.
Von Foerster was influenced by the Vienna Circle and Ludwig Wittgenstein. He worked in the field of cybernetics and is known as the inventor of second-order cybernetics. He made important contributions to constructivism. He is also known for his interest in computer music and magic.
In 1949 von Foerster started work at the University of Illinois Urbana-Champaign at the electron tube laboratory of the Electrical Engineering Department, where he succeeded Joseph Tykociński-Tykociner. With his students he developed many innovative devices, including ultra-high-frequency electronics
He also worked on mathematical models of population dynamics and developed a general model now called the "von Foerster Equation" 
He was the youngest member of the core group of the Macy conferences and editor of the five volumes of Cybernetics (1949–1953), a series of conference transcripts that represent important foundational conversations in the field. It was von Foerster who suggested that Wiener's coinage "Cybernetics" be applied to this conference series, that had previously been called "Circular Causal and Feedback Mechanisms in Biological and Social Systems".
A 1960 issue of Science magazine included an article by von Foerster and his colleagues P.M.Mora and L.W.Amiot proposing a formula representing a best fit to available historical data on world population; the authors then predicted future population growth on the basis of this formula. The formula gave 2.7 billion as the 1960 world population and predicted that population growth would become infinite by Friday, November 13, 2026 - von Foerster's 115th birthday anniversary - a prediction that earned it the name "the Doomsday Equation."
Based on population data obtained from various sources, von Foerster and his students concluded that world population growth over the centuries was faster than an exponential. In such a situation, doubling-time decreases over time. Von Foerster's tongue-in-cheek prediction of Doomsday on November 13, 2026, was based on an extrapolation into the future of doubling-time, with the finding that doubling-time would decrease to zero on that date.
Responders to his Doomsday prediction objected on the grounds of the finite human gestation time of 9 months, and the transparent fact that biological systems rarely persist in exponential growth for any substantial length of time. Those who knew von Foerster could see in his rejoinders an evident sense of humor.
Recent research has confirmed the basic soundness of von Foerster's findings. The hyperbolic growth of the world population observed until the 1970s has recently been correlated to a non-linear second order positive feedback between demographic growth and technological development that can be spelled out as follows:
Von Foerster authored more than 100 publications. Books, a selection:
Articles, a selection:
Dictionary and translator for handheld
New : sensagent is now available on your handheld
A windows (pop-into) of information (full-content of Sensagent) triggered by double-clicking any word on your webpage. Give contextual explanation and translation from your sites !
With a SensagentBox, visitors to your site can access reliable information on over 5 million pages provided by Sensagent.com. Choose the design that fits your site.
Improve your site content
Add new content to your site from Sensagent by XML.
Crawl products or adds
Get XML access to reach the best products.
Index images and define metadata
Get XML access to fix the meaning of your metadata.
Please, email us to describe your idea.
Lettris is a curious tetris-clone game where all the bricks have the same square shape but different content. Each square carries a letter. To make squares disappear and save space for other squares you have to assemble English words (left, right, up, down) from the falling squares.
Boggle gives you 3 minutes to find as many words (3 letters or more) as you can in a grid of 16 letters. You can also try the grid of 16 letters. Letters must be adjacent and longer words score better. See if you can get into the grid Hall of Fame !
Change the target language to find translations.
Tips: browse the semantic fields (see From ideas to words) in two languages to learn more.