The Circular Reasoning in the Superluminal Ban: A Logical Note on the Einstein Synchronization Convention

The standard argument holds that superluminal signals would allow the construction of closed timelike curves (CTCs), leading to causal paradoxes, and therefore superluminal signaling is impossible. This note points out that this argument is operationally circular. The coordinate time t' in the Lorentz transformation is based on Einstein's synchronization convention, which presupposes the isotropy of light. This note does not claim that superluminal signals exist, nor that relativity is wrong. It only points out that in inferences with v>c, the use of global simultaneity exceeds the scope of its operational definition. This is a logical note, not a refutation. It provides a bug-fix for the textbook antitelephone argument and proposes TCLM t_trunk as a possible repair direction. Full derivation with V=0.8c, v=2c is included. Chinese Title: 超光速禁令中的循環論證:一個關於愛因斯坦同步約定的邏輯注記