There have been several explanations advanced for the Fermi paradox
ranging from a short finite life of civilization - The view advanced
by Von Neumann amoung others, to us living in a simulation.

The most disconcerting possibility is a Fermi race. This assumes that
a small, if not just one, number of civilizations will send Von
Neumann probes to the stars and will occupy the galaxy. The galaxy
comes on a first come, first served basis.

There has been lots of speculation. Perhaps it would be a good idea if
we were to discuss how we could choose experimentallly between one
possibility and another. If we did have a 1km telescope we could find
out how many worlds there were with oxygen in their atmosphere and
hence photosynthesis. If there is any truth in the "race" hypothesis
the cost of a telescope might well be justified on security grounds.


- Ian Parker