> The ability to warp spacetime to the point of violating causality, time travel, might be a death nail for a civilization. death knell I know you probably kn

> The ability to warp spacetime to the point of violating causality, time travel, might be a death nail for a civilization. death knell I know you probably know this, and I don't mean any disrespect. I'm writing this for other people who don't speak English natively (I'm also not saying you're not a native speaker, just that I'm not). I don't want anyone to go away with the wrong idiom.