Trey Jones <Trey2@aboveREaverageMOdriverVE.com> wrote in message news:<v4qiivs3q3o3blho0r1tn49vplne2cpdne@4ax.com>...

On Tue, 29 Jul 2003 13:16:01 GMT, Dale Hurliman
<hurliman@no.spam.please.sunlink.net> wrote:

Erik Max Francis wrote:

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

 
 Robert J. Kolker wrote:

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

	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.

So, certain patterns that might at one time be thought to be a sign of
technology, intelligence, or other deliberate action can have natural
sources. For example, a very strong, insanely regular pulse might
have, at one time, have been the mark of a clock-maker with OCD. Now
it's more likely to be a pulsar.

A exponential pattern (over a short range) could conceivably be
natural. Any continuous, exponetially increasing output (think
explosion) which, from our point of view, is gated (say, something
orbits insanely rapidly around something else, blocking our view
except for brief, regularly spaced snippets when gravitational lensing
gives us a view)--would appear as a sequence of blips of exponentially
increasing magnitude, at least for a short while. It's a stretch, but
you get the idea.

A non-intelligent but biological (maybe chemical?) source could give
off exponentially patterned signals (something eats, divides, then
emits a signal) at least for a while, until the "food" ran out.
Bacteria come to mind as following the growth pattern, but aren't very
good at emitting signals that travel interstellar distances. Other
possibilities? Some sort of synchronizing clock to keep everyone in
synch would be nice, too.

If you have a power-of-two type pattern, it's easy to get Fibonacci
numbers out of the system.. be born, grow, eat, give birth, emit a
signal, eat, give birth, emit a signal, eat, give birth, emit a
signal, etc. If the growing takes one eat-birth-emit cycle, you get
fibonacci numbers.

Even primes seem abstractly possible.. The Sieve of Archimedes (was it
Archimedes? I can't recall at the moment) gives a vaguely plausible
framework for nature to emit primes. Start with some source of things
with integral frequency (starting at 2, though).. but where each
prevents the creation of new items that have a frequency that's a
multiple of itself.. so 2 is created, then 3 is created, as 4 is about
to be created, 2 emits a signal, which also prevents the creation of
4. 5 is created, then 2 and 3 both emit a signal preventing the
creation of 6. Then 7, 2 blocks 8, 3 blocks 9, 2 and 5 block 10, 11 is
created, etc, etc.

The pattern would be complex, but the primes would be detectable if
you looked hard enough. What's a possible source? I have no idea, but
the non-intelligent mechanism is there.

Binary digits seem plausible.. something at one end of a chain is
driven by an unseen source.. the first item flips state from 0 to 1,
then flips from 1 to 0, but emits a particle/signal/blast of energy
that causes the next item up the chain to flip from 0 to 1. The least
significant bit flips twice more, emits, flips bit #2, which emits,
and flips bit 3... etc etc. Given some odd but possible physical
constraints, this seems doable.

So.. a few questions: 

What are some concrete possible sources of interstellar signals
exhibiting these patterns? 

What other patterns could plausibly be created naturally? 

...snip...


A couple of naturally caused patterns I've read about (I borrow and
edit the following snippett from a part of an old post from me):

1,1,2,3,5,8,13,21,34
.
.
..
...
.....
........
.............
.....................
..................................

Fibonacci sequence (1st two terms are 1, each successive term is the
sum of the preceding pair of terms) which can be related to musical
scales, reproduction in various animals like the bee and rabbit, and
the patterns in pine cones and sunflowers.


........
................
........................

0,8,16,24 this arithmetic sequence might also represent an Archimedian
spiral (which can be found in a spider web.)

.
...
.........
...........................

1,3,9,27 this geometric sequence might also represent a logarithmic
spiral (such as a spiral galaxy, like ours.) If they did 1,3,9,27 and
then had space of time and did another non-logarithmic number, let's
say between 9 and 27, one might guess that they were telling us where
they were in the galactic disk they were, with 27 representing the
entire spiral and the non-logarithmic number being their location out
from the center of the galaxy.

(A little off target on that last paragraph, but perhaps food for
thought?)
Regards, Jason H.