How do you explain it?

[Aiken]

Alneyan said:Therefore, the destruction of the homeworld is the key to a successful expansion to nearby stellar systems, so long as you do focus on spreading all the settlers a lot: if they all went to the same planet, you would have to repeat the whole process from scratch.

Hidjra (ar.) - massive exodus of terrans from Earth in XXII century due to a cataclysm caused by a black hole placed into the Earth's core. See: "Hyperion"(Simmons), "Dying Earth" b. I-XXXII (Silen).

Those damn scifi writers stole all our ideas before we even make them up!