Diminished Capacity

Aliens Redux

A while back, I posted an entry called "Statistics and Aliens" where I claimed that the Drake Equation, a famous way of estimating the number of intelligent civilizations in our galaxy, may be wrong because it assumes statistical independence. I also noted that the possibility that we would be able to intercept the internal communications of other civilizations seems remote to me because information theory dictates that the better the technology, the more noise-like a communication will seem.

I've now found an article in New Scientist from a few weeks ago in which Frank Drake himself notes that our own technologies are making us harder and harder for aliens to hear (and thus presumably their technologies might make it hard for us to hear them), though the article doesn't mention the same information theoretic grounds that I do.

Also, so far as I know, I've seen no one else who questions the assumption of statistical independence in the Drake equation, which seems strange. Is anyone aware of another source that mentions that problem?