Any civilisation that reaches our stage of development will require 20–40 million years to colonize the entire galaxy (without using hypothetical FTL drives). All advanced civilisations in our galaxy are older than ours (we have just got there, in the last millisecond of cosmological time). If just one percent of all advanced civilisations would be interested in colonizing the galaxy (i.e. 99% would for some reason not be) then our solar system should be teaming with alien life forms (or at least their artificial successors). I will be writing extensively about this in my biographical blog here in Medium. The last part of this article, Is it a bird? Is it a plane? It’s a bird, Sergey…, is a teaser.