Marvin <kitfox@pixie.co.za> wrote in message news:<4092c082.0@news1.mweb.co.za>...

What the SETI@home system has shown us, is that there are no earth-like(in 
terms of electromagnetic broadcast) inhabited system within a distance of 
about 400 light years. There are no alien civilisations deliberately 
beaming messages aimed at us within about 5000 light years.

This is not correct.  SETI@home (or any other SETI so far) is not
sensitive enough to detect a civilization radiating like ours from
*any* star, even the nearest.  They all need a much stronger signal,
presumably deliberately aimed our way, to have any chance of
detection.  So what SETI@home has shown so far is that after a search
of 1/3 of the sky, no one is sending us strong signals and constant
signals in that particular frequency band (perhaps 1/100 of the best
frequencies).  So we don't have any sort of a strong negative yet.

    Lou Scheffer