The Subtle Contradiction at the Core: Why QED, Though Nearly Perfect, Cannot Be Truly Complete

This paper reinterprets Richard Feynman's use of negative time within quantum electrodynamics (QED) through the lens of the "Special Time Loop Paradox" (STLP), a thought experiment designed to expose logical contradictions in time-reversal scenarios involving faster-than-light motion. While QED remains one of the most accurate and successful physical theories in terms of experimental predictions, we argue that its reliance on mathematical devices—particularly time-reversed solutions—hints at a deeper incompleteness. Our analysis suggests that these "mathematical tricks" may not merely be calculational tools but indicators of a foundational limitation.