From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Sat Apr 26 2003 - 11:39:28 MDT
On Sat, 26 Apr 2003 ABlainey@aol.com wrote:
> This is what I see as very important in the detectable civilisations
> argument. The most efficient way to communicate is point to point. Any
> advanced civilisation trying to communicate over large distances would/should
> be using this method. As we do when communicating with satellites, spacecraft
> or intercontinental phone calls, etc.
Interestingly, NASA is moving in the direction of laser pulse communication
for satellites, perhaps even interplanetary communications. The pointing
requirements are pretty strict, but given the possibility of increasing
at least ground based receiver sensitivity (just use a bigger mirror) the
power requirements for the transmitter drop quite significantly and the
data rate goes up significantly.
> Unless we are in the footprint or line of sight of a transmitter And are
> actively searching in the frequencies being transmitted, then we aint gonna
> find squat.
My opinion exactly. How long will broadcast TV remain??? With things like
the TiVo it looks like its days are numbered. With cable & video on demand,
and one would hope eventually fiber to the home, handling more of the
information delivery chores, then there isn't going to be much being broadcast
into space. One would suspect that such signals might have a lifetime
of ~100 years for an advancing civilization. It seems unlikely that
we could catch them.
Robert
This archive was generated by hypermail 2.1.5 : Sat Apr 26 2003 - 11:48:53 MDT