The computer as a modelling machine, a history of analog computing
The computer as a modelling machine a history of analog computing Charles Care http://www.warwick.ac.uk/go/ccare 26th June 2006
History of computing• Story of the progression of technology• Popular to trace the history back to – calculating machines (e.g. abacus, sliderule) – data processing technologies (e.g. punched cards) – early office machinery (e.g. typewriters) – early communications technology (e.g. telegraphs)
Computers and Engineers• Use computers to represent physical systems and natural phenomena• … problem solving mediated by – …differential equations – …other notations• …computers solve the problem by – …numerical methods – …more direct techniques• Supported by engineering knowledge, experience and trust.
An alternative historyA recent conference... attempted to map out the history of software, considering it as science, engineering, labour process, reliable artefact and industry...The focus lay on software and its production as general phenomena. What the conference missed was software as model, software as experience, software as medium of thought and action, software as environment within which people work and live.It did not consider the question of how we have put the world into computers. (Mahoney, 2005)
From experimental to computational • Progression from one-off modelling to the development of a laboratory science of aeronautics. – Full size – one-off model – model in wind tunnel – electrolytic tank (special purpose analog) – general purpose analog – general purpose digital.
Aircraft Flutter – a complex problem…flutter calculations required on a modern aircraft are usually beyond the scope of a desk calculating machine, and high speed computational aids have become a necessary adjunct to flutter prediction. (Templeton, 1955)• Royal Aircraft Establishment developed ‘flutter simulators’ (analog computers)
Aeronautics and analog/digital• ARC computation panel – Wilkes: “No desire to discourage anybody from doing work which may get results, but in the near future when there were more digital machines … analogue machine building just would not be able to keep up with them.” – “Diprose viewed with alarm the implied tendency to build up large programmes and so have the arithmetical processes divorced from the physical problem.” (Meeting 3 pp 2 – 3, 1953)
Why did analog persist?• Superiority of digital was understood• But digital was not fast enough• Issues relating to training engineers in programming• Engineering trust – how reliable is a program• Closed shop computing vs open shop interaction• Users rather than inventors.
My research• The history of an analog computer installed at British Petroleum (BP)• The role of analog computers in higher education (HE), and the agency of higher education in the development of analog• Analog/digital applications and use in aeronautics• The relationship between analog computing and ‘soft’ computing.
Analog computing at BPEMIAC computer installed atBP, Sunbury (1962)
Modelling machines• Engineering knowledge and modelling• Campbell-Kelly and Aspray (2004) – Focus: Office machines, communication, and data processing – Theme: computer as information machine• My work – Focus: Modelling, engineering design, simulation, and analog computers – Theme: computer as modelling machine
Aeronautics and analog/digital• Perceptions of superiority – “…when the automatic digital machine became established…[many suggested] that analogue was obsolete. This view is no less widely held.” (Diprose, 1955)• Trial and error process – “The analogue machine… is more convenient where the problem is itself tentative and experimental… where the choice of later calculations may depend on the results of earlier ones.” (Hollingdale and Diprose, 1953)
Post WWII analog computing• Problems with this history – View past with the eyes of the present – Focus on successes rather than failure – Small (2001) – c.f. Hamilton (1997)
Role of Users• Cybernetic story – Role of feedback – Humans and Machines working together. – Mindell (2002)• Connections with Empirical Modelling – Human Computing
References• Anon. Minutes of the Computation Panel of the ARC. TNA DSIR 22/206. 1952-3.• K. V. Diprose. Analogue computing in aeronautics. Copy of of a lecture given to the Royal Aeronautical Society. TNA DSIR 23/23384, 1955.• Martin Campbell-Kelly and William Aspray. Computer: A History of the Information Machine. 2nd. ed., Westview Press, Colarado, 2004.• Ross Hamilton. Continuous path : the evolution of process control technologies in post-war Britain. PhD thesis, University of Warwick, 1997.• S. H. Hollingdale and K. V. Diprose. The role of analogue computing in the aircraft industry. TNA DSIR 23/21372, 1953.• David A. Mindell. Between Human and Machine: Feedback, Control, and Computing Before Cybernetics. The John Hopkins University Press, Baltimore, 2002..• James S. Small. The Analogue Alternative: The Electronic Analogue Computer in Britain and the USA, 1930-1975. Routledge, London, 2001