A short history of the digital twin

The idea of a running copy of a real thing, kept up to date with what happens to the original, is older than its name. A 2021 NASA keynote by B. Danette Allen says the idea was born at NASA in the 1960s, as a "living model" of the Apollo mission.¹ After the oxygen tank explosion on Apollo 13, NASA used several simulators to work out what had failed, and extended a physical model of the vehicle with digital parts.¹

The idea had been imagined for places before it had its name. In Mirror Worlds, published in 1991, the Yale computer scientist David Gelernter imagined looking at a screen and seeing an image of your city with its traffic moving.² Or the screen might show the state of a whole company at this second.² Any citizen could look in, for example to explore how the local schools were doing.² The book also explains how such a program could be built with the technology of the day.² The wiki has an entry on the book: Mirror Worlds.

Two accounts of virtual cities date from around 2000. A chapter by Risto Linturi, Marja-Riitta Koivunen and Jari Sulkanen in the 2000 Springer collection Digital Cities is titled "Helsinki Arena 2000 - Augmenting a Real City to a Virtual One".³ In 2002 Toru Ishida wrote an article titled "Digital city Kyoto" in Communications of the ACM.⁴

The name came from manufacturing and aerospace. Michael Grieves writes that he introduced the concept of a virtual, digital equivalent to a physical product in 2003, in his University of Michigan executive course on product lifecycle management.⁵ His model had three parts.⁵ There is the physical product in real space and the virtual product in virtual space, and there are the links of data and information that tie the two together.⁵ He writes that he introduced the term "Digital Twin" in his book Virtually Perfect, and that he attributed it to John Vickers of NASA, with whom he works.⁵ Open Library dates that book to 2011.⁶

At NASA the term appears in a November 2010 draft roadmap for modelling, simulation, information technology and processing, written by a team chaired by Mike Shafto.⁷ It defines a NASA digital twin as a simulation of a vehicle or system that combines physical models, sensor updates and fleet history "to mirror the life of its flying twin".⁷ The roadmap lists four uses.⁷ They are flying a mission in simulation before launch, following the real flight as it happens, diagnosing the cause of a serious fault or damage, and studying changes to the mission that were not considered when the vehicle was designed.⁷ The April 2012 version of the roadmap keeps the same definition.⁸

Also in April 2012, Edward Glaessgen of NASA and D. S. Stargel of the Air Force Office of Scientific Research presented a paper on the digital twin to a structures conference in Honolulu, in a session given over to the subject.⁹ Their definition speaks of an "as-built" vehicle: the twin models the vehicle as it was made, including its defects and fabrication anomalies.⁹ A footnote says the paradigm was originally conceived by the Defense Sciences Office at DARPA.⁹ They list the NASA roadmap among their references.⁹ Grieves and Vickers later wrote a chapter on the digital twin and unpredictable, undesirable emergent behaviour in complex systems, which Springer published in 2016.¹⁰

In Britain in 2018, the Centre for Digital Built Britain and the Digital Framework Task Group published the Gemini Principles, named after the Latin for twins.¹¹ The paper is about the built environment and its infrastructure.¹¹ It defined a digital twin as "a realistic digital representation of assets, processes or systems in the built or natural environment".¹¹ It said that what sets a twin apart from other models is its connection to the physical thing it twins.¹¹ It also proposed a national digital twin.¹¹ This would not be one huge model of the entire built environment.¹¹ It would be many twins, each kept by the owner of the assets it models, joined by securely shared data only where that delivers value.¹¹ One of its examples is a new wastewater treatment plant.¹¹ By bringing together the twins of the water, energy and transport sectors, its effect on power demand and on traffic on local roads could be modelled.¹¹ The paper notes that NASA had run complex simulations of spacecraft for decades.¹¹

City-scale twins now include heritage work. In 2025 a team from the University of Bradford, with co-authors from the city council and elsewhere, described Virtual Bradford.¹² They built it in partnership with the council and call it one of the first open-data city-scale twins at that level of detail.¹² It covers the city centre, including several conservation areas and multiple listed buildings.¹²

The term is still used loosely. A 2020 paper by Louise Wright and Stuart Davidson says it is applied in many different ways, often without saying how a twin differs from a model.¹³ They describe the basic parts of a twin as essentially a model and some data.¹³ This wiki uses the phrase in that broad sense, for models and simulations of places; see What is a digital twin?.