Originally posted by OzChris
do we actually meaningfully SEND OUT radio waves in the hope of something recieving it and paying us a visit?
Chris
Hi Chris!!
We certainly have done this ie "beamed" signals deliberately to stars in the hope that "somebody" up there will receive them. For example the
Arecibo broadcast
"In 1974, the most powerful broadcast ever deliberately beamed into space was made from Puerto Rico. The broadcast formed part of the ceremonies held
to mark a major upgrade to the Arecibo Radio Telescope. The transmission consisted of a simple, pictorial message, aimed at our putative cosmic
companions in the globular star cluster M13. This cluster is roughly 21,000 light-years from us, near the edge of the Milky Way galaxy, and contains
approximately a third of a million stars."
Of course, all this was highly specualtive - 42k years "round time" is rather extreme, but it demonstrated the resolve - and put into place
techniques (like coding signals of *what* to send) - which was really the point behind it. And it sure was much cheaper than attempting to send a
rocket 21k LY away!!
Thanx Chris!!