[ExI] Double-Earth (Was: kepler study says 8.8e9 earthlike planets)

[Anders Sandberg]

Incidentally, found this lovely review of plutonium physics:
http://www.fas.org/sgp/othergov/doe/lanl/pubs/00818035.pdf
That is one tricksy metal.

-- 
Dr Anders Sandberg
Future of Humanity Institute
Oxford Martin School
Oxford University