A Failure of Serendipity: the Square Kilometre Array will struggle to
  eavesdrop on Human-like ETI
  The Square Kilometre Array (SKA) will operate in frequency ranges often used
by military radar and other communications technology. It has been shown that
if Extraterrestrial Intelligences (ETIs) communicate using similar technology,
then the SKA should be able to detect such transmissions up to distances of
~100 pc (~300 light years) from Earth. However, Mankind has greatly improved
its communications technology over the last century, dramatically reducing
signal leakage and making the Earth "radio quiet". If ETIs follow the same
pattern as the human race, will we be able to detect their signal leakage
before they become radio quiet? We investigate this question using Monte Carlo
Realisation techniques to simulate the growth and evolution of intelligent life
in the Galaxy. We show that if civilisations are "human" in nature (i.e. they
are only "radio loud" for ~100 years, and can only detect each other with an
SKA-like instrument out to 100 pc, within a maximum communication time of 100
years), then the probability for such civilisations accidentally detecting each
other is low (~10^{-7}), much lower than if other, dedicated communication
techniques are permissible (e.g. optical SETI or neutrino communication).
