Meh, the boring answer is that it's probably common, but interstellar detection ...

cwillu 10 months ago | parent | context | favorite | on: Carl Sagan, nuking the moon, and not nuking the mo...

Meh, the boring answer is that it's probably common, but interstellar detection and signalling is very hard, and interstellar travel is impossible with the materials available in a single star system.