The Observer and Spacetime: On the Existential Precondition of Physical Theory [The Observer Series P1]
The preprint version is available on SSRN: The Observer and Spacetime: On the Existential Precondition of Physical Theory (August 18, 2026). http://dx.doi.org/10.2139/ssrn.7316678 [The Observer Series P1] The Observer and Spacetime: On the Existential Precondition of Physical Theory Juliet Zhong Independent Researcher | London, United Kingdom | August 2026 ORCID: 0009-0006-5099-3671 Abstract This paper argues that the observer is not a peripheral element in physics but the existential precondition without which physical theory loses its empirical content. Using a series of thought experiments grounded in special relativity, the paper demonstrates that the construction of a reference frame—the foundational operation upon which all of relativistic physics depends—requires an entity capable of measurement, and that measurement, in every instance, presupposes an observing system. When this precondition is removed, the formal apparatus of special relati...