lazaros

The "local" relevance is important since traveling using a ship is... a local event for the ship+cargo. The expansion of the universe used as proof of FTL is a non sensical argument: the time space continuum can have an expanding boundary or it might not. Beyond that hypothetical boundary there might be space/time or not. Whatever you believe or think you know, whichever ideas you adhere carry a set of consequences. Causality is not a physics or engineering problem: it's theology. At some point a new type of physical laws might give us a way to achieve FTL. For now we need to use ideas based on the factual reality we comprehend. 5℅ 10℅ c is enough to reach our closest stars in a few decades. It can also make expanding humans to our solar system viable, efficient, and unfortunately profitable. I studied physics, got my Msc, my PhD because I wanted a lightsaber and my own Millennium Falcon. I can still dream and hope.