WHAT is the secret of innovation? There are many explanations. “You start with some very bright people, let them hang out with other very bright people and allow their imaginations to roam,” is how Susan Hockfield, the president of the Massachusetts Institute of Technology (MIT), sums it up. But there seems to be an important local factor too.

Babbage has been along to an exhibition which has just opened at the MIT museum as part of the celebration of the institute's 150th anniversary. Staff, students and others were asked to help pick the 150 artefacts that have been included. The idea is that these things illustrate not just some of the breakthroughs MIT has been involved with, but also the character of the institute. Some 700 nominations were made to a website and these were voted on.As to be expected it is an eclectic mix. MIT's exploits have ranged widely since it was founded by William Barton Rogers in 1861, just two days before the start of the American Civil War. Items on show include breakthroughs in engineering, electronics, medicine and design. There is a Technicolor film camera from the 1930s; Vannevar Bush's 1931 differential analyser, which was a milestone in the development of analytical machines; the Whirlwind Computer, which started life in 1947 and was later used in radar development; instruments developed for NASA's Voyager spacecraft launched in 1977 and still transmitting data. There are also modern inventions, like a battery running on genetically engineered viruses and an electric car. And there are more obscure artefacts which have given MIT its flavour, such as a 1970 recording of an impromptu concert at the campus by the Grateful Dead.But there is also a group of exhibits which show how MIT has used its own backyard as something of a laboratory. One of the earliest are the research notes of Ellen Swallow Richards, MIT's first woman graduate, who from 1887 made a detailed examination of the public water supplies in Massachusetts. There were concerns about pollution from industrial waste and sewage, and her work led to the first state water-quality standards. A prototype of the “Boston Arm” is also on display. This came about when Norbert Wiener, an MIT professor, was recovering in 1962 from a broken hip in Massachusetts General Hospital. He speculated with doctors about how servo mechanisms might be used to link the brain to an artificial limb. The doctors got together with Robert Mann, also an MIT professor, and used lightweight power units developed for a missile system to come up with an arm that could be controlled by the user's muscle impulses.There are many other examples of local innovation. A collection of postcards represent the work of Spiros Geotis, who in the early 1960s got Boston TV viewers to send him postcards with details of hailstorms. This information was used to verify data obtained by MIT's radar and showed that it was possible to use radar to predict not only the location of storms but also their intensity. A group of wooden models of downtown Boston were used in MIT's Wright Brothers wind tunnel by Frank Durgin in the 1970s to explore wind-shear conditions. Among the problems were windows falling out of the 60-storey John Hancock Tower. And today's Boston has been transformed, represented by a 1970s model of a massive project promoted by Frederick Salvucci, an MIT lecturer. This led to the removal of a shabby elevated highway and put the roads underground, reconnecting the city with its waterfront.Other hot centres of innovation seem to show a similar working relationship with their local communities. Silicon Valley certainly does. And like those places, it is not just Boston that has benefited from such creativity. MIT calculates that its living alumni have founded 25,800 companies that currently provide 3.3m jobs for people around the world. These firms have combined annual revenues of some $2.2 trillion. Perhaps all those politicians and planners seeking to foster centres of innovation need to start local.