Robustness of Results and Robustness of Derivations: The Internal Architecture of a Solid Experimental Proof

Abstract

According to Wimsatt’s definition, the robustness of a result is due to its being derivable from multiple, partially independent methods, and increases with the number of such methods. In the case of the experimental sciences, the multiple methods will amount to different types of experiments. But clearly, this holds only if the convergent derivations involved are genuine arguments, that is, if each of them can be considered as sufficiently reliable or solid. Thus, the issue of the robustness of results inevitably leads to a reflection on the solidity of methods. What is, then, that makes a method, and in particular an experimental procedure solid? Despite the possible worries of circularity, part of the answer lies, without doubt, in a sort of reversed formulation of Wimsatt’s definition: the solidity of a method will increase with the number of independent results, previously established as robust, that it will enable to be derived. But this seems to be only a part of the answer. Intuitively at least, it is expected that the solidity of a method could also be linked to specific properties of this method, to features that are more ‘intrinsic’ than the results it allows to derive. In this chapter, I try to probe into the nature of these ‘intrinsic’ characters, through a discussion of an example connected to the discovery of weak neutral currents in particle physics. More precisely, the method that will be investigated is an experimental procedure developed at the beginning of the 1970s, which uses a giant bubble chamber named Gargamelle, and which is commonly believed to have contributed to establishing the existence of weak neutral currents. I analyze the content of the Gargamelle experimental ‘proof’ and bring to light its internal architecture. Then I examine the relations between this architecture and the wimsattian scheme of invariance under multiple determinations. Thereafter, I specify this scheme, and draw some general conclusions about the solidity of methods and results. Finally, some implications with respect to the issues of scientific realism and the contingency of scientific results are sketched.