Publication Identifier 150201 TitleUnobservability of short-lived unstable particles and its implications for observational claims and theories in physics Type of publicationpreprint Author(s)M.J.T.F. Cabbolet Contributor(s) Keywordsexistential knowledge; observation; observational claims; elementary particles; Standard Model; correctness; completeness Publisher Source Publication date2015-02-03 LanguageEnglish AbstractThe physics literature contains many claims that elementary particles have been observed: such observational claims are, of course, important for the development of existential knowledge. Regarding claimed observations of short-lived unstable particles in particular, the term `observation' is not used with reference to any particular concept of observation: physicists merely use the word `observation' based on the convention in physics that the observation of a short-lived unstable particle can be claimed when its predicted decay products have been observed with a significance of 5 sigma. However, using Fox's recent concepts of direct and indirect observation, this paper shows that unstable particles with a lifetime of less than 0.01 attosecond are fundamentally unobservable. This cognitive inaccessibility of parts of the subatomic world has far-reaching implications for physics, not the least of which is that the aforementioned convention is untenable: claims that such short-lived unstable particles have been observed will thus have to be retracted. The main implications are two incompleteness theorems for physics, respectively stating (i) that experiments cannot prove completeness of a physical theory predicting short-lived unstable particles, and (ii) that experiments cannot prove correctness of such a theory - one can at most test its empirical adequacy. On a general note, the conclusion is that the importance of philosophical arguments for particle physics is herewith demonstrated: it is, thus, a widespread misconception that philosophical arguments can be completely avoided. CopyrightOpen access