Walter asks, If we find that there really is stuff that runs faster than the speed of light, is this discovery simply a new empirical fact about the universe we can add to the other ones, or does it constitute a "paradigm shift" in Kuhn's terms? The answer is "No." It has been a long time since I read Kuhn, but as I recall his argument no single finding, however major, would constitute a paradigm shift, though it might stimulate one. Why? A paradigm is not a theory. A paradigm is a way of doing science, a set of conventional procedures. A theory may be invoked to provide a rationale for that set of conventional procedures, and a finding that contradicts the theory may set in motion changes in practice that alter the procedures in question. Then again, it may not. The theory may be adjusted to account for the new finding without fundamentally altering the way in which the scientists in question go about doing science. This sort of adjustment is, moreover, commonplace in what Kuhn calls the "normal science" phase of a science's development. Of course, my memory could be failing me. John -- John McCreery The Word Works, Ltd., Yokohama, JAPAN Tel. +81-45-314-9324 jlm@xxxxxxxxxxxx http://www.wordworks.jp/