Here’s something from my son Ed in California that might be interesting:

 Last Saturday we went to the Hat Creek Observatory to visit the new SETI array under construction.  They’re putting up 350 20 X 24 foot dishes to listen for radio transmissions over a 3 degree arc of sky (six times the diameter of the moon).  The lecture and questions dwelled heavily on things I didn’t care about like funding sources and wavelengths.  But I was able to squeeze a few questions in and learn some interesting things.  Here’s a bullet list:

• Science really is being advanced while they listen for signs of intelligence that may never come.  For instance, they can focus on a distance galaxy and learn its chemical composition and how fast it’s going.
• The biggest limitation is not the sensitivity of the array to pickup signals, but the processing ability of the computer to make sense out of 350 simultaneous transmissions. A good computer would cost $1.5 million and increase the array’s usefulness by a couple of orders of magnitude.  I got some hint of this data-crunching task from Carl Sagan’s book Contact, in which a transmission caught the astronomer’s attention by spewing a series of prime numbers.  Further analysis of the signal revealed multiple levels of information that eventually turned into an instruction manual on how to build a machine to visit the aliens.
• If aliens set up an identical SETI. array on a likely nearby planet (say 25 light years away) and aimed it at us, and all the governments of Earth pooled all their broadcasting power to send a signal to the aliens.  It wouldn’t