Conceptual and Technological Revolutions

There are two kind s of scientific revolutions, those d riven by new tools and those d riven by new concepts. Thomas K uhn in his famous book, The Structure of Scientific Revolutions, talked almost exclusively about concepts and hard ly at all about tools. His id ea of a scientific revolution is based on a single example, the revolution in theoretical physics that occurred in the 1920s with the advent of quantum mechanics. This was a prime example of a concept-d riven revolution. K uhn's book was so brilliantly written that it became an instant classic. It misled a whole generation of stud ents and historians of science into believing that all scientific revolutions are concept-d riven. The conceptd riven revolutions are the ones that attract the most attention and have the greatest impact on the public awareness of science, but in fact they are comparatively rare. In the last 500 years, in add ition to the quantummechanical revolution that K uhn took as his mod el, we have had six major concept-d riven revolutions, associated with the names of Copernicus, Newton, Darwin, Maxwell, Freud , and Einstein. During the same period there have been about twenty tool-d riven revolutions, not so impressive to the general public but of equal importance to the progress of science. Two prime examples of tool-d riven revolutions are the Galilean revolution resulting from the use of the telescope in astronomy, and the Crick-Watson revolution resulting from the use of X-ray d iffraction to d etermine the structure of big molecules in biology.

The effect of a concept-d riven revolution is to explain old things in new ways. The effect of a tool-d riven revolution is to d iscover new things that have to be explained . In almost every branch of science, and especially in biology and astronomy, there has been a prepond erance of tool-d riven revolutions. We have been more successful in d iscovering new things than in explaining old ones. In recent times my own field of physics has had great success in creating new tools that have started revolutions in biology and astronomy. Physics has been less successful in creating new concepts with which to und erstand its own d iscoveries.