Space Forum / SETI / June 2008

Probably the most significant factor which would need to be taken into
consideration is to what extent ET wants to be found. With current
technology we can't detect signals that just happen to leak out, except
perhaps for the very nearest stars. What we're hoping for is that some
ETs want to be found and are aiming narrow band beacon signals in our
direction. In our case, we have only sent a handful of such signals
since we developed suitable technology.

    It is not possible as the Drake equation is all unknowns. Only after finding
the first handful will it be possible and then based upon nothing in the
equation.

    Consider 20 years ago asking how long before discovering the first planet
around another star. There would be no way to answer no matter how fancy an
equation is available because none had been found. Today we can take the total
number examined and the number found and come up with a ballpark. But that
question is more interesting as it is conditioned on how they were found and
better methods being developed and so forth.

    It will be the same with ET. Presuming we start finding ETs in the
foreseeable future it will be long before we can fill in the blanks in the
Drake equation unless one of those ETs has the answers and tells us. The
variables in the equation would take a massive survey of a huge number of
stars likely in the tens of thousands to get a first approximation of the
variables.

    But hearing a few ETs jumps to the answer without knowing any of the Drake
variables. With the first few refined search methods will be developed. If
there are similarities among them then some will narrow the search just for
the commonalities like type of star or type of signal. If that works we could
find dozens of ETs without knowing any more about the variables than we did
when Drake wrote it down.

A quick fast and easy algorithm for the location relation and assocation of
Extra terretrail life on SETI to Sirius:

Time: Oct 12 2006ADCE, 1:44 pm
Distance: 60ly
Link: http://www.usag-ac.info/cgi-bin/view.cgi?id=313

START
a:={x in P:0<x<inf}, P!2
a=succ(x)(f+z)

{
    x-=SUM[z=-inf...0]az^-1)
}

{
     PRINT "hello"
}
else
{
     REPEAT BEGIN UNTIL value==x
     x=RANDOM()
     RESTART
}
REPEAT 666 TIMES SIGNAL "0 0 0 1 11 000"
STOP

P:prime

Why SETI has not found evidence for extra-terrestrial intelligent life.

I've read recently that Stephen Hawking is surprised that we haven't yet
detected civilizations communicating with signals we can recognize and try
to signal back to them.

To me this is an unsurprising result. To explain why let me detail some of
my career experience. Many years ago I was on the faculty at MIT and taught
subjects relating to communications theory. I learned in detail Claude
Shannon's theories of communications. It's a shame that what he did is not
more broadly understood and appreciated. His theories of communications are
every bit as important and valid as Einstein's theories and the Second Law
of Thermodynamics.

What Shannon showed was that the way to communicate the most information,
with the fewest errors, and the least energy is to use the largest part of
the available bandwidth you can. You also modulate your signals in a way
that they look like noise. The narrow band intelligent appearing signals
SETI has been looking for matches our historical (primitive) signaling
methods, but not what an advanced civilization would be propagating. SETI
has been looking for signals that belong to an emergent technological
society, not one further along.

When you look at our own history of using the electromagnetic spectrum what
happens with a technological civilization is clear. We started more than a
century ago with "spark gaps", then controlled narrow band signals, and have
advanced to "noise-like" modulation that begins to approximate Shannon's
theory and achieve optimum results. Importantly, our primitive use of the
spectrum (what SETI has been searching for) lasts for perhaps a century or
so, and then a technological civilization such as ours "goes dark" and
cannot be detected. This is why Hawking is unable to find alien
civilizations in the signals SETI is looking for. The overlap in development
of their detectable "Amos and Andy" radio era (my short-hand for the SETI
type signaling) with the rest of the cosmos is so short that finding it is
almost impossible to uncover in signals one might be looking for.

Our "open communications" century must be overlapped with the billions of
years of the history of the Universe in which other technological
civilizations, if they exist, they must have passed through. We must also
think of more advanced communications technologies we haven't even thought
of yet: modulating neutrino beams, relaying messages over long distance
through worm hole relay stations, and other exotic possibilities that
competing technological civilizations will have had thousands, millions, or
even billions of years to achieve!

My expectation then is that we WON'T find ET. We are too primitive and ET,
if there, is too advanced. If we want a SETI that will work, we need to
start looking for the Shannon type of signals by speculating on how
civilizations more advanced than we are might propagate their signals and
look for them!

Walter M. Anderson