The speed of causality is a fundamental speed limit. It is also the speed of light, the speed of gravity waves and so the limit on the speed of communication or

The speed of causality is a fundamental speed limit. It is also the speed of light, the speed of gravity waves and so the limit on the speed of communication or travel. Exceeding the speed of causality would allow the creation of contradictions which as far as is known, are not possible and would subvert physics.