Seth was the first to notice that when other scientists were asked
"when will we find the signal?", the answer was typically just before
that scientist would retire. I'm not sure of his age or plans, but I
suspect Seth will retire before 20 years.

The reasoning behind "20 years" is that with certain assumptions about
the factors in the Drake equation, and the transmitter, and etc., Seth
concludes we need to search about a million stars with good sensitivity
over a wide range of frequencies. We plan to search a million or more
stars at the ATA. How long that will take depends a bit on the
efficiency with which we deal with terrestrial signals, but it could be
twenty years.

I, personally, do not make any predictions. ;-)

The Gas Giant wrote:
"Rob Dekker" wrote:

Where does this 20 year number come from ?

Can't remember where or when I heard it, but I distinctly heard Shozzy
say "because that's when I'm retiring." Sounds reasonable to me!

With 200 billion stars in the Galaxy, and 10,000 ETI civilizations,
Each of these ETIs need to send beacon signals to an average of
10million stars in its neighborhood continuously.

With a message reading:

"Simply send 6 x 10^50 atoms of hydrogen to the star system at the top of
the list, cross off that star system, then put your star system at the
bottom of the list and send it to 100 other star systems. Within one-tenth
of a galactic rotation you will receive enough hydrogen to power your
civilization until entropy reaches its maximum! IT REALLY WORKS!"

'-)