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From: BARD@MIT-XX.ARPA
Newsgroups: net.sf-lovers
Subject: Another reason for not being visited
Message-ID: <3142@topaz.ARPA>
Date: Tue, 6-Aug-85 13:26:12 EDT
Article-I.D.: topaz.3142
Posted: Tue Aug  6 13:26:12 1985
Date-Received: Thu, 8-Aug-85 00:27:22 EDT
Sender: daemon@topaz.ARPA
Organization: Rutgers Univ., New Brunswick, N.J.
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From: Bard Bloom 


There aren't all that many stars close to us.  Anyone visiting Sol 
with the intent of visiting us probably found out about us by old radio
shows, and they haven't been flying around for all that long -- and I don't
know how easy it would be to detect them over solar radiation, and even 
cosmic  background noise.  Our neighbors, if any, probably don't know we're
here.  

Does anyone know whether OZMA could detect Earth at the distances it's
using?

Also, anyone visiting us would have to be close in time as well as space.
Now, 1,000 years is barely noticable on astronomic time scales (most of the
time, anyways).  There's enough randomness in evolution that, if two planets
evolve life at the same instant (Please, no flames about simultaneity!), and
the life follows similar patterns, they probably won't evolve sentient life
within 1,000 years of each other.  

I'd be suprised if there were anyone else within listening distance of us.


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