archive: Re: SETI modulation of ETI transmission

Re: SETI modulation of ETI transmission

Noel C. Welstead ( (no email) )
Wed, 02 Sep 1998 09:00:36 +1000

I had and idea the other day when I was watching my fftdsp display. I
see patterns in the display. You know, like the ink blot test idea. It was a
months ago that I saw a strange pattern (ENTIRELY NATURAL) that gave me
the idea that a signal could be frequency shifted by computer in such a way as
provide a pattern that could be detected as a geometric design. This idea is
to the way a laser beam is modulated rapidly to create a picture on a wall or
By cunningly altering the frequency a few tens of hertz on the fly you could
create a
"pattern" in the frequency shift that a program like FFTDSP4.2 could project
onto the
time domain display. I would see this pattern very clearly and notice that it
was unusual.
Without knowing about the modulation scheme you could communicate ideas with
simple pictures with ease. After establishing simple communications like this
you could
advance to more complicated concepts. No need to worry about how to decode the

data, it's right there on the waterfall display for all to see. I guess, you
could liken it
to cosmic kindergarten drawing lessons, without getting paint on your fingers.

Noel C. Welstead.
SETI League Volcor Brisbane Australia.

Daniel Boyd Fox wrote:

> Okay, I'm going to put forward a crazy idea and why I think the idea is
> not so crazy.
> When we think of radio waves we normally think of sine waves, but there is
> nothing in nature that says a radio wave has to be a sine wave. While it
> is true that a square wave can be broken down into the sum of an infinite
> series of sine waves, a sine wave can also be broken down into an infinite
> series of square waves. In fact, any periodic waveform can be broken down
> into the sum of a series of any other periodic waveform. Keep this in
> mind.
> Now, one discovery in research on fractals were sounds that when recorded
> and played back at half speed sounded the same. In fact, there were a lot
> of interesting tricks that could be played with these fractal sounds. If
> these tricks can be done with sound then they can be done with radio
> waves. Doppler shifted white noise still sounds the same, but there may
> well be another nonsinusoidal radio wave that will stand out in the noise
> and not be effected by doppler shift.
> Anybody care to dig into the idea?
> 73,
> Daniel Fox