Roga wrote:
I think SETI makes far too many assumptions. It is very geared toward
the Drake equation, which is a pragmatic narrowing of information
bandwidth to the point where we're only looking for messages that are
sent with the express purpose of talking to us. Considering that we
have only sent one of these messages ourselves, and only for a tiny
period of time to a star that will not respond for 50000 years anyway,
it's not terribly strange that we haven't found anything.

It is likely that, with efficient compression, alien radio data will be
indistiguishable from white noise. By definition, the more efficient a
compression algorithm, the more random its output. So, even if we can
pick up the radio communications that are strong enough to reach us but
not specifically meant to be sent to us, it is not likely that our
current pattern-finding algorithms will find much of a pattern at all.
It will just look like another star.

However, we can predict the general shape of the spectrum of a star by
it's temperature. If we know the amount of radio (or microwave, or
visible) light that a star *should* emit, why don't we just look for
anomalies in the blackbody curve? For instance, anybody looking at the
Sun would see a yellow-orange star with way too much energy in the
radio spectrum. Furthermore, there would probably be a slight, but
maybe detectable, circadian period to the intensity.


Perhaps the biggest advantage of this is that it is necessarily a
broadband approach -- instead of scanning for patterns at a thousand
very specific bands, it would allow for a full-spectrum view. Also, it
would be easy enough to adapt SETI@Home to search for blackbody
anomalies, and the mere act of pulling together full spectra on so many
stars would be much more useful than just having their signatures on
the Hydrogen line, which by definition they don't really have much of
anyway.

If nothing else, this would be a way to narrow down the field of
candidate stars significantly. Is this being done? If no one is doing
it, maybe I will.

I think that this is an excellent post. A lot of the SETI work does
seen to assume aliens very like us in terms of technology and approach
to communication. Some lateral or creative thinking does seem to be in
order, given the lack of plain language radio detected hitherto. It
could be that radio itself is replaced by an obviously better form of
transmission quite early in a civilisation's technological advancement.
Phased neutrino's anyone?