I'm watching Star Trek and I had a thought. How do we expect to receive signals from alien civilizations when we don't know how they communicate? I'm not talking about the language but rather the technology. For years we searched for radio communication but that didn't produce anything. Recently we started looking for signals that are based on laser communication technology.
I found this funny because I had conceived of a laser communication device for a game I was designing once. I thought, as apparently SETI does as well, that light based communication would be a more likely for a space faring species. Light might not be the right way to think though. This is where Star Trek comes in.
In the Star Trek universe communication is handled over subspace. Subspace is a sort of 'alternate' universe linked to our own but with slightly different properties. Physics is different and transmissions through subspace appear to be nearly instantaneous across vast distances in normal space.
I'm not saying we have to find subspace but we do have to consider that a form of faster than light communication might be the only way space fairing species talk to each other. We may never find radio or light based communications due to distance or interference from astronomical phenomena. We would have trouble ourselves using light based communication to chat with vessels at the edge of our own solar system. Subspace type communication might be more reliable.
If a subspace communication system exists then it may be easier to detect alien communications. If communications can travel so quickly in subspace than it's possible it's much smaller in 'area' than our universe. If so than it would require far less time to search for signals. It also possible that subspace communications are instantaneous and universal. In that case we simply need to tap into this pipeline and all alien communications could be accessed.
This is all random thoughts while watching Star Trek of course. We currently have no good evidence of any sort of extra-dimensional existence. We are still trying to get a good understanding of sub-atomic particles which will more than likely be the key to accessing any type of subspace. One day we might tap into the alien radio network but it will be some time if we keep looking for what I would consider 'short-range' signals. I might just need a nap though.