Originally Posted by RhodyDave
Are you sure you have anything useful to contribute? If the signal were strong enough and we could decode it, we could learn a hell of a lot, both socially and technologically. It would be immeasurably transformative.
Societies in the habit of using radio waves to transmit data many light years might pick a form that would be resistant to undecodable distortions. You can pack a hell of a lot of error correction into a signal at the cost of transmission throughput. We are idiots to think that if such was to be used, they'd just blast out a signal like we would, though degradation would, of course, make inter-solar-system signals, not designed for such, almost impossible to detect, much less successfully decode.
And yes, deliberate signals would (probably) be more direction-focused, so we'd have to "luck out" that we got in the line of sight of one. But again, depending on the topology of their civilization, the required throughput rates, and the cleverness of their error correction, maybe even that might not be required. Maybe a 9 volt omni-directional transmitter could transmit across the galaxy, or between galaxies, with a clever enough error correction scheme.