Linearity Quotes
Considering the pervasive importance of quantum mechanics in modern physics, it is odd how rarely one hears of efforts to test quantum mechanics experimentally with high precision....The trouble is that it is very difficult to find any logically consistent generalization of quantum mechanics. One obvious target for generalization is the linearity of quantum mechanics, but if we arbitrarily add nonlinear terms to the Schrodinger equation, how do we know that the theory we obtain will have a sensible physical interpretation? At least in part, it is the dearth of generalized versions of quantum mechanics that has made it so hard to plan experimental tests of quantum mechanics.
Steven Weinberg
Most observers in the 1870s would have been far more impressed by its linearity. In material terms, in terms of knowledge and the capacity to transform nature it seemed so patent that change meant advance that history – at all events modern history – seemed to equal progress. Progress was measured by the ever rising curve of whatever could be measured, or what men chose to measure. Continuous improvement, even of those things which clearly still required it, was guaranteed by historical experience. It seemed hardly credible that little more than three centuries ago intelligent Europeans had regarded the agriculture, military techniques and even the medicine of the ancient Romans as the model for their own, that a bare two centuries ago there could be a serious debate about whether the moderns could ever surpass the achievement of the ancients, and that at the end of the eighteenth century experts could have doubted whether the population of Britain was increasing.
Eric Hobsbawm
