1. If I travelled in a wormhole from Earth to a distant star 10 LY away, and arrived there instantly, when would I arrive at the star? Would I be there 10 years ago, as the light took 10 years to reach Earth? If Minkowski space is truly 4D i.e., space-time, then I can't arrive at some objective 'now' since there is no common instant in time common to any two points in space no matter how close or distant. The only common 'now' would be the 10 year old photons reaching Earth - as I leave and arrive at the distant star 10 LY away... I should be there at the same time the photons left the star, 10 years ago????? Relativity doesn't apply for v >c, i.e., instnataneous travel. Isn't this the same as two very distant entagled particles or photons - or a double slit experiment, violating causality? 2. If two ships each leave a common point speeding away from each other equally at v = c, to a distance of 2LY (1 LY travel for each) and each turns around and speeds back to the starting point at v = c, do their clocks agree? Unlike 1 ship speeding away and back (twin paradox) , there's no fixed reference.