Spreading happiness to the stars seems little harder than just spreading Imagine there are two advanced interstellar civilizations near one another who begin outward colonization around the same time, in an other...
reflectivedisequilibrium.blogspot.com
@niplav @cerebrate But why spread at all? Unless you can bypass the speed of light any exosolar colonies would have to be so autonomous as to be practically independent polities, which might decide to launch RKVs instead of tribute shipments.