This dissertation attempts a resolution of the apparent tension between objectivity and conventionality in modern physics. It is argued that the physical sciences, though dependent on convention, may nevertheless produce objective representations of reality. In demonstrating this, a view of representation is introduced which explicitly includes the human subjects between whom representation actually takes place; this view is termed, 'representation as performance.' These human subjects are, as ever, sources of subjective ambiguity in representation. Nevertheless, representation may still be substantially objective. It has been suggested that objectivity may be conceived in terms of group theoretical invariance. Rejecting Hermann Weyl's well-known proposal along these lines, a new notion, 'objectivity of alignment,' is introduced which rehabilitates the notion of objectivity as related to invariance. Even within representations which are objective in this sense, however, remaining ambiguities present themselves which must be resolved through various kinds of conventional choice. Two case studies illustrate this argument, relating to the 'twin paradox' of special relativity and the localization of a single particle in relativistic quantum mechanics. It is shown that objective representations of the twin paradox rely on the invariant, 'proper time,' but that even such objective representations contain certain conventional ambiguities. To show this, a novel scheme for unifying the various versions of the twin paradox is presented and elucidated. In the case of localizing a quantum state, it is shown that the choice of how to recover objectivity is also one of convention, made on the basis of a number of criteria. In the process it is also shown that Hegerfeldt nonlocality can be understood as arising from what is termed the 'Jericho effect;' in addition, a direct evaluation of the Hegerfeldt integral is provided. Thus in both case studies objectivity and conventionality need not be held permanently in opposition.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:598483 |
| Date | January 2001 |
| Creators | Debs, T. A. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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