Homeostat
Encyclopedia
The Homeostat is one of the first devices capable of adapting itself to the environment; it exhibited behaviours such as habituation, reinforcement and learning through its ability to maintain homeostasis
in a changing environment. It was built by William Ross Ashby
in 1948 at Barnwood House Hospital
. It was an adaptive ultrastable system, consisting of four interconnected Royal Air Force
bomb control units with inputs, feedback
, and magnetically driven, water-filled potentiometers. It illustrated his law of requisite variety — automatically adapting its configuration to stabilize the effects of any disturbances introduced into the system. It was the realization of what he had described in 1946 as an "Isomorphism
making machine".
When Alan Turing
heard of Ashby's intention to build the Homeostat, he wrote to Ashby to suggest that he could run a simulation on Turing's Automatic Computing Engine (ACE) instead of building a special machine.
In 1949 Time described it as "the closest thing to a synthetic brain so far designed by man".
In 1952, Ashby demonstrated it at the ninth Macy conference on cybernetics
. In the same year he published a description of the Homeostat in his influential book Design for a brain. In total, between 1946 and 1967, he wrote 38 entries about the Homeostat in his journal.
Homeostasis
Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
in a changing environment. It was built by William Ross Ashby
William Ross Ashby
W. Ross Ashby was an English psychiatrist and a pioneer in cybernetics, the study of complex systems. His first name was not used: he was known as Ross Ashby....
in 1948 at Barnwood House Hospital
Barnwood House Hospital
Barnwood House Hospital was a private mental hospital in Barnwood, Gloucester, England. It was founded by the Gloucester Asylum Trust in 1860 as Barnwood House Institution and later became known as Barnwood House Hospital. The hospital catered for well-to-do patients, with reduced terms for those...
. It was an adaptive ultrastable system, consisting of four interconnected Royal Air Force
Royal Air Force
The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
bomb control units with inputs, feedback
Feedback
Feedback describes the situation when output from an event or phenomenon in the past will influence an occurrence or occurrences of the same Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence an occurrence or...
, and magnetically driven, water-filled potentiometers. It illustrated his law of requisite variety — automatically adapting its configuration to stabilize the effects of any disturbances introduced into the system. It was the realization of what he had described in 1946 as an "Isomorphism
Isomorphism
In abstract algebra, an isomorphism is a mapping between objects that shows a relationship between two properties or operations. If there exists an isomorphism between two structures, the two structures are said to be isomorphic. In a certain sense, isomorphic structures are...
making machine".
When Alan Turing
Alan Turing
Alan Mathison Turing, OBE, FRS , was an English mathematician, logician, cryptanalyst, and computer scientist. He was highly influential in the development of computer science, providing a formalisation of the concepts of "algorithm" and "computation" with the Turing machine, which played a...
heard of Ashby's intention to build the Homeostat, he wrote to Ashby to suggest that he could run a simulation on Turing's Automatic Computing Engine (ACE) instead of building a special machine.
In 1949 Time described it as "the closest thing to a synthetic brain so far designed by man".
In 1952, Ashby demonstrated it at the ninth Macy conference on cybernetics
Cybernetics
Cybernetics is the interdisciplinary study of the structure of regulatory systems. Cybernetics is closely related to information theory, control theory and systems theory, at least in its first-order form...
. In the same year he published a description of the Homeostat in his influential book Design for a brain. In total, between 1946 and 1967, he wrote 38 entries about the Homeostat in his journal.
External links
- Homeostat in the Principia Cybernetica Web.
- The Homeostat simulation by Dr Horace Townsend.
- The W. Ross Ashby Digital Archive includes a biography, bibliography, letters, photographs, movies, and fully indexed images of all 7,400 pages of Ashby's 25 volume journal.
- W. Ross Ashby (1956): An Introduction to Cybernetics, (Chapman & Hall, London): available as a PDF, Principia Cybernetica Web, 1999