A simple model of grabby aliens

Abstract

Given a hard-steps model of advanced life timing, our date now seems very early. One explanation is: an early deadline set by “grabby” civilizations (GC) who expand rapidly, never die, and prevent new GC from arriving in volumes they control. If we might become grabby, our date is a sample GC origin date. A selection effect explains why we don’t see them when they control ~40% of universe now. Each parameter in a 3 parameter model can be estimated to within an order of magnitude, allowing narrow estimates of GC spacing, appearance, and duration till see or meet them.