Dale Hurliman <hurliman@no.spam.please.sunlink.net> wrote in
news:3F2672FF.7060104@no.spam.please.sunlink.net: 

Robert J. Kolker wrote:

Erik Max Francis wrote:

SETI is looking for deliberate, unambiguous signals, not
accidental ones. 

Like Jodi Foster getting the sequence of primes. There is
no way in hell for that to be random noise.

Bob Kolker

     

     We do not know that for sure.  Random numbers seem to
     be distributed 
along the number line in a random fashion. And nuclear
excited states (energy levels) seem to be distributed
somewhat like random numbers. What this all means is not
clear at the moment. 
     You might like to see _Prime Obsession: Bernard Riemann
     and the Greatest 
Unsolved Problem in Mathematics_, by John Derbyshire.

Note however that modern trend in data transmission, encryption 
and spread spectrum signals will tend to produce a planetary 
signal that is indistingishable from random noise.

So we are left with cultures that have developed radio, but not 
yet realized that the enemy listens to radio also (like ww1 
naval signals), or developed computers to optimize transmitions.