Re: SETI: SAT Spread Spectrum indistinguishable from normal star? (was Re: Movie ;contact)

Henri Kluytmans (
Thu, 13 Nov 1997 19:04:03 +0000

On Sun, 9 Nov 1997, Steve Witham wrote:
> I guess interstellar stealth will be
> mainly developed to hide from *local* enemies--people from your own
> planet with technology similar to or somewhat better than yours.

On Mon, 10 Nov 1997, Philip Witham wrote:
>My point was that invisible (to us primitives) communication is an
>inevitable consequence of using the avalable bandwidth to anything like
>it's potential. No need to hide, those puny humans can't even hear us
>when we're screaming in their direction!

Isn't the amount of energy required for transmission of more concern
than using the available bandwidth to it's limit. I.e. is using
a directed and focused beam instead of using a unidirectional
pulsating star for transmission, a lot more energy efficient.
Also by directing a focused beam you can prevent your
"enemies" from detecting anything. (No need for stealth.)

If you're using a pulsating star to transmit a unidirectional signal
it seems that the purpose is to get attention instead of hiding
yourself or your transmission.

Furthermore a signal totally indistinguishable from random noise, so
without any redundancy, will not be able to correct any errors
created by damage to the signal, and should therefore not be

(Indistinguishable from noise, that means every single photon
should carry an important bit of information. So the loss of a
single photon should result in loss of information.)

>Hkl  -------------- 
Because the future is where we will spend the rest of our lives ...
You see things and ask "Why?"  ;  I dream things and ask "Why not?"