Propulsion
...we use molecular scale automata to prolong our lives. This maintenance gives us time to construct the structures necessary for our trek.." Lohi was saying. "We use several millions of classes of molecular automata to construct antimatter production facilities. John interrupted, "We can only produce a few nanograms of antimatter in our labs. It takes years to make that much. It seems there are barriers to faster production..." "Barriers yes!" Lohi interrupted, "we use the matter in a solar system to make billions of arrays of production facilities. Only on this scale can we produce enough to be practical for inner-system propulsion." "Inner-system? Then how… " he collected his thoughts, “if you come from as far as you say, how do you travel between galaxies?!" Lohi's mind expanded to encompass the memory of the first of hundreds of launches; the launch of their 100 km long ship to the nearest suitable star syste...