Abstract
This paper revisits Herbert Dingle's well-known critique of special relativity, focusing on his "inconsistency argument" concerning the symmetry of time dilation. After briefly outlining the historical context and philosophical significance of Dingle's objections, we present a renewed and physically grounded reformulation of his challenge. Using a thought experiment with two inertial spaceships equipped with identical 'radioactive clocks', we show that special relativity leads to a dilemma: either both observers must record identical proper times, contradicting the Lorentz transformations, or they must record different proper times, violating the principle of relativity. We argue that this dilemma exposes a fundamental tension between the relativity principle and the standard interpretation of time dilation.



![Author ORCID: We display the ORCID iD icon alongside authors names on our website to acknowledge that the ORCiD has been authenticated when entered by the user. To view the users ORCiD record click the icon. [opens in a new tab]](https://www.cambridge.org/engage/assets/public/coe/logo/orcid.png)