I wonder whether we are being naive in the way we search.

Even looking at the history of Earth should push us to question our assumptions. The Inca Empire was a large civilisation with sophisticated political, economic and cultural systems. But they didn't use the wheel, or iron- and their system of recording information via knotted pieces of string (quipu) is something that would have never even occurred to people elsewhere. It's quite possible that radio is our quipu- we assume everyone else must use it, because it seems natural to us to do so, but only because we've never imagined the equivalent of writing, a different communication technology that other worlds are using but we're not searching for because we don't have any concept of what it is, never mind how to look for it.

Of course, since we're talking about hypothetical life formed in different conditions and with distinct evolutionary history (maybe even a different chemical basis), the divergence is likely to be orders of magnitude greater than that between different civilisations formed by members of the same species on the same planet in a very short time window. Whatever's out there, we may not even be able to recognise it.

We've already scanned large areas of sky specifically for this with no positive results, so as much as I used to think the galaxy must be teeming with life I would be extremely surprised if we found anything. If funding is there though, it is worth a punt but the reality is, in order to reliably find anyone, they would have to be broadcasting high-power radio signals in a continuous beacon-like fashion; and who would do this, we certainly don't! Maybe we will get lucky though.

Another point of interest is this kind of discussion always brings up very misanthropic sentiment (quite understandably), but if you subscribe to the principle of mediocrity, which is pretty much the basis of cosmology (invariance of physical law), then aliens are probably very similar if not identical to us seeing as the same chemical/physical/biological, and therefore environmental, constraints that went in to making us would statistically also have fashioned their evolution. With that in mind, I don't think it such a great idea to advertise our presence to people who may already be significantly ahead of us technologically - we would have little notion of what their capabilities really were. If this is logical and not just human angst, it is likely that other civilisations feel the same.

Ideally encrypted signals look completely random. No repetition, no pattern, zilch. After only 100 years or so we're phasing out unencrypted signals. In another 100 years they simply won't exist. Exactly why do we think alien civilisations would be any different? A brief period of clear signal followed by white noise." ( )

Let's Go!

Davies presents a good survey of the science, theology and philosophy involved in considering the question, "are we alone in the universe."

And there is all sorts of value in exploring, with rockets and radios, to answer the question. Even when our results are unclear, the tools and techniques we created extend our capabilities. ( )

Premature to write this ...