laser broom
“Why will we use green lasers for starwisp and light sail propulsion? “Because stars aren’t green. Can’t be green, in fact, because a black-body spectrum that peaks in the green is broad enough that there’s plenty of other-colored light to make it not sum to green. That
blogging from a to z
xenognosis (n.): (also “the Big Hello”) The knowledge that sophont species other than one’s own exist; also, the discovery by an individual or species that they exist. In popular mythology, this is usually conflated with first contact, or at least with the establishment of genuine communications between the species