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Missile Defense

Russian military leaders have expressed concern about US plans for a national missile defense system. Will defense technology be limited by possibilities for a strategic imbalance? Is this just SDI all over again?

rshowalter - 09:19am Mar 19, 2001 EST (#1165 of 1166)
Robert Showalter showalte@macc.wisc.edu

4.3. A Relevant Philosophical Idea

What I have called the “Guideline of Scholarly Controversy (Kline 1995, p 195, op cit) will help us understand how things develped and point us toward the future. This guideline states, “When two (or more) groups of scholars create conflicting solutions for a single problem, then it is likely that each group of scholars has some of the truth, but not all of it.” This implies that no adequate solution has existed. In such cases we need to seek an improved solution that reframes the problem in a way that encompasses ALL The credible data and provides a consistent, adequate solution.

From 5.5

(a recitation of anamolies, motivating a change in paradigm) "Thus over the 15 years from 1956 to 1971, several things became clear. Active structures go right to the wall. The wall layers are not unstable in the usual sense of that word . .. . .(more detail ..)

rshowalter - 09:20am Mar 19, 2001 EST (#1166 of 1166)
Robert Showalter showalte@macc.wisc.edu

5.6 Paradigm Conflict

"In his famous book on “Scientific Revolutions,” Thomas Kuhn (1962) says several things that help understand the shift from the Statistical Era to the Structural Era.

. Most science evolves incrementally inside a common overview held by the vast majority of workers in the area. Kuhn called such overviews “paradigms” noting that paradigms often include many specifics that transcend a general view.

. There are nearly always data that contradict the currrent paradigm. Over a long time span contradictions sometimes accumulate, and may ultimately lead to a shift in the controlling paradigm for a given class of problems. However, existing paradigms are not abandoned until a significantly better paradigm is created (because we cannot think about complex topics without some paradigm; see concluding remarks.)

. Workers who have used the old paradigm for many years (often including leaders of the technical community) usually strongly resist the acceptance of the new paradigm.

"All the elements described in the three bullets above occurred in the shift from the statistical to the structural paradigm.

"An accumulation of contrary data did occur as noted above. The shift was strongly contested by some workers who had worked for a long time within the statistical paradigm. They suggested, rightly, that unless great care is used one can read virtually anything one is looking for into the patterns of flow visualization in turbulent flows. However, over the period between 1956 and 1971, enough data accumulated to convince most workers that the statistical paradigm was not adequate, and that the production of Reynolds stresses and turbulent kinetic energy occurred as the result of “quasi-coherent eddies” which extract energy from the mean flow and increase overall dissipation. These eddies involve correllated motions as opposed to mere random fluctuations like those of molecules of gas. Many aspects of the forms of these eddies remain under contention. Nevertheless by the early 1970’s most workers were convinced that the new paradigm was correct. Indeed John Laufer who had initially been one of the most skeptical individuals about the visual evidence was kind enough, and of sufficient stature, that he wrote me saying that he had been very skeptical initially, but the results cited above had convinced him that what the Stanford group had said about the role of the ejections from the sublayer was at least partially correct.

( to be continued )

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