Back to Home

God & Science Forum Message

Forums: Atm · Astrophotography · Blackholes · Blackholes2 · CCD · Celestron · Domes · Education
Eyepieces · Meade · Misc. · God and Science · SETI · Software · UFO · XEphem
RSS Button

Home | Discussion Forums | God and Science | Post
Login

Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...
The Space and Astronomy Agora
There Is No Way Of Detecting Useful Radio Signal From Far.

Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response To
Posted by Alexander on December 18, 2001 20:42:28 UTC

If you are far enough, the quality of information you detect essentially degrades because it is quantizied by E=hf "bits". So, if on planet X you receive less quanta per antenna area per second than the signal content (in bits/sec), you will not be able to distinguish content from noise even if antennas are covering entire planet. Simple calculations show that our Earth's becomes practically radioinvisible from distances of a few light-days only. Account for Sun's background radio-noise makes it even less visible. Accounting for inherent detector noises -even less.

There is technical possibility to beam very little information - small number of bits per second (like a Morse code) to a few light-year distances IF YOU KNOW WHERE EXACTLY TO DIRECT NARROW RADIO-BEAM (to where certain planet will be in several years when the beam will arrive). Also,I wonder, will it have much sense to communicate with the speed of few bits per second anyway? How much info can we send and receive?

And still what to do with 1000s years delay in getting answer if indeed civilisations are scattered over large distances? (Actually, 1000 light years is quite optimistic - it basicly means that there is about 10^4 civilizations in it at any given time. Most likely, the # of civilisations is much less, so mean distance between them is in 10^4 + light years range.

At such distances radiocommunication is likely impossible at all.

Follow Ups:

Login to Post
Additional Information
Google
 
Web www.astronomy.net
DayNightLine
About Astronomy Net | Advertise on Astronomy Net | Contact & Comments | Privacy Policy
Unless otherwise specified, web site content Copyright 1994-2018 John Huggins All Rights Reserved
Forum posts are Copyright their authors as specified in the heading above the post.
"dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET"
are trademarks of John Huggins