posted on Jun, 18 2013 @ 07:58 PM
Originally posted by phishyblankwaters
reply to post by Saint Exupery
Well, the root assumption is that anyone deliberately beaming communications across interstellar space wants to be understood. Otherwise, why
We've been beaming television and radio out into space since we invented it, inadvertently. This could also be true for E.T.
I knew someone would say that. This is one of those times when definitions are important, so forgive me if I get pedantic.
TV & radio (the music, news, etc. kind) are not beamed
, they are broadcast
- i.e. transmitted in all directions. This causes the signal
strength to drop-off very rapidly, and thus they are likely to be too weak to detect at interstellar distances (in Carl Sagan's book "Contact", he
got around this by giving the aliens a planet-sized receiving array at Vega).
The term "beaming", in the context of this discussion implies a strong directional signal, like a flashlight or a laser. As others have pointed
out, the higher the frequency, the tighter the beam (which means less signal loss and thus longer detection range). A larger antenna also improves
In fact, we have
been beaming radio energy into space for decades in the form of radar - particularly
Ballistic Missile Early Warning radar
. Radars searching for ICBMs coming over the north
pole is probably the most detectable signal that we transmit. However, it only says - inadvertently - that we are here. It does not carry a message,
This why, in my post that you quoted, I specifically and deliberately used the phrase, "deliberately beaming communications across interstellar
Hope this clears things up.