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From: Fractenna@aol.com
Return-path: <Fractenna@aol.com>
To: seti@sni.net
Subject: Re: SETI Re: Is radio the last word?
Date: Wed, 3 Feb 1999 10:01:38 EST
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In a message dated 2/3/99 9:15:18 AM Eastern Standard Time,
n6tx@setileague.org writes:
<<
> It was because the uplink assumptions were so poor in the Cyclops Report
>that OSETI has been held back for a quarter of a century.
>
> So in actual fact, the laser approach is far superior Of course, if
>it is easier (for an ETI) to generate very large laser powers, the FOM on a
>non-watt for watt basis might be even higher.
>
> Have a look at my diagrams which indicate a 14 dB improvement of a
>symmetrical 10 meter 656 nm link over a symmetrical 300 meter 1.5 GHz link:
> >>
Hello Stuart--
Tell us what the gain of your large apertures are and their solid angles
please. Then tell us how the FOM is better than a lower gain system--notice I
didn't say microwave-- which is monochromatic and operates at, say, a region
of the spectrum where the noise is, oh, 15-20 dB less.
Your FOM must be strongly defined by the number of candidate stars
studied--from both transmit and receive (which is easier) end. Talk about
dwell times and slew times, and so on.
Is it practical to transmit at 10,000 stars this way? 1000000 stars this way?
1000000000 stars this way? Show us how.
The issue isn't laser. It's gain. Point to point versus something more like
'broadcasting'. (I do not mean isotropic or omni so please don't insult my
intelligence on this(anyone)). No one has EVER been able to demonstrate that
point to point approaches have ANY advantage over the latter.
IF your point(no pun intended) is that lasers are a superior point to point
system, for local communication then--bully! We discussed this via e-mail in
September and October as you recall. So, for all the spiky headed droids who
live in alpha Centauri or 61 Cyg that want to talk with us, let them send
laser messages. Of course, why would there be ANY--unless the density of alien
civs is so high that life is a galactic infestation. Some hypothesis...
An observation predicated on close-by ET's is not a scientific one: It
addresses and answers no scientific question other than some contrived, super-
limited construct.
The universe is up for cherry picking friends; why should we possibly be
interested PRIMARILY at the blade of grass at our feet, rather than the 100
acre wood beyond?
Regards,
Nathan Cohen, Ph.D.
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