Radio waves were beyond the concept of plato and aristotle. In all their pholosophies and explanations in the world, never once did they come close to imagining that radio waves existed, or could be used in the ways they're now used.

In my life alone, and I'm fairly young, the paradigm of what is possible and even required for human civilization has changed. When I was young, we were still reeling from our briefest forays into space, a few hundred thousand miles above the surface of our planet, to the moon. In contrast, the space station is a mere couple hundred miles away, closer to us than an Atlantic Ocean crossing.

Computers were in their advent when I was young, and I was witness to the rise of a trend called 'personal computing' which took the computer out of the mainframe and into desktops around the world, and changed the way we functioned. Even more radical, and certainly not something I could have seen coming at my age, was the advent of the internet. While networks were powerful, the internet brought a network to end all networks, and first with BBSes, and then with actual WWW servers, my life changed forever. How I communicated, how I studied, researched, and all around interacted with the world changed.

Now, I cary a phone with more processing power than my first 10 computers put together, with a faster network connection than I would have dreamed possible in 1985 when Seti began. The rise of Cell Phones has again shifted our paradigm to a new way of looking at ourselves, and at communication.

I have no idea what the next shift will be.

I hope that the singularity comes, and I get to be a part of the beautiful chaos that it will cause, much as I've been a part of the beautiful chaos that the internet (Napster anyone?) has caused, and the beautiful chaos that the entire information age has caused. I think that the singularity will at once be certain things, and in other ways be things I can't imagine, because I lack the language and the understanding that it will change.

But do I know what the next change in our thinking will be?

Not at all.

I don't think this makes sense--the Drake equation bundles this into a constant, fc that's the fraction of civilizations that emit detectable signals. Talking about how hard it is to understand the variety of signals just says we have no way of estimating these constants.

I probably should have been more explicit. I think the point that we can't estimate the values need to apply the Drake equation is probably* spot on. But that doesn't mean the equation is untrue. I think you're running those two issues together.

* As a rule, I think we should almost never say "we can't know x", except in rare cases where something is provably unknowable, because we're constantly surprising ourselves. A better thing to say is "right now, we have no clue how to answer question x".

P.S. I said lower bound, because of the points about dispersion mentioned in the wiki article--depending on how you count, if one civilization arises, then colonizes several planets, that makes for multiple civilizations that we might communicate with (ditto for panspermia hypotheses earlier on the process).

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Occupy Babel!

Once we have overcome the lightspeed barrier in communicating, we will suddenly see that there are hundreds of extraterrestrial intelligences in our galaxy. And then they will welcome us in the world of modern communication.

I think you're confusing new discoveries with new conceptual capacities. If the conceptual capacity was never there, the discovery couldn't possibly happen.

If your point was, as jts has said, that we simply may not have discovered the technology/scientific principle that would allow us to know what to look for to find intelligent life, then I definitely agree. It's hard to tell though, because you're not just talking about technology. You're also talking about cultural shifts, and I really don't think our culture has much to do with it. Discovering radio waves and implementing them for communication would be sufficient to build a project to detect radio wave signals from other life. The presence of radio 'culture' involving music broadcasting, the development of soap operas, implementation of propaganda in the new medium etc... is not necessary in the least.

Maybe they're too busy trying to solve Go to bother with us. But yes, I agree it is unreasonable to assume that we would easily recognize other forms of life, or that they would use the same methods of transmission as we do.

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"Those who calculate greatly will win; those who calculate only a little will lose, but what of those who don't make any calculations at all!? This is why everything must be calculated, in order to foresee victory and defeat."-The Art of War

Actually, most fo that last post was aimed at the statement that I seemed to be claiming to know what the next paradigm shift would be/would be like.

I do think, however, that culture has a lot to do with what we look for. An early 1900s scientist might look for radio waves, with the assumption that the information would come in Amplitude Modulation, which is the simplest form of informational encoding on a radio wave. A late 1990s scientest would look for FM, PSK, and half a dozen other ways of implementing data encoding which may have sounded like random noise to earlier scientists, a change brought about by scientific advances made in the demands of a culture(More data on the same wave).

If you sent a message to Herz in the form of FM radio, he'd likely never hear it, and he had radio detectors.

You can know a signal is present without knowing what it means, certainly, but some of what we have discovered are ways to create a signal would have been beyond us without further refinement of data transmission. The culture drove that refinement.

Communication, particularly with intelligent beings who do not share our language, is hinged upon culture, the capability to find some culturual middle ground or nuetral space which allows the building blocks of communication to grow.

In short, my point is this: We likely lack the technology to detect any attempts to communicate with us, and lack a culture which could begin to relate to starfaring beings capable of communicating across the astronomical distances involved.

Even if tomorrow we found a signal in the aether from alien life, we'd lack the tools necessary to understand it, and might not even recognize it for actual communication because of our cultural and scientific lack.

Culture is an inescapable part of how we humans communicate. Our cultures, our global and scientific cultures, our culture of techology, limits and defines our search for extra terrestrial intelligence.