Counter to a simple SWI Fermi argument

[Eric Hawthorne]

On the likelihood of detecting alien intelligences:
(single-world case)

1. It is an enormously stupid conceit of us to assume that
aliens would be broadcasting, or tightbeaming something like
analog radio signals, for communication.
We ourselves have only being doing that for 100 years,
and will be ceasing to do it before the next 100 are up,
having switched to a combination of closed fibre-optic and
massively spread-spectrum (i.e. noise-like) digital radio.


2. We have not built dyson spheres, nor are we likely
to. There were a number of crazy megaproject engineering
fantasies that we had for the first few short years after
we discovered how to build with reinforced concrete, and
Dyson spheres were one of them. (As were those incredibly
ugly but functional 60s and 70s concrete skyscrapers. The
first crude phalluses erected using a new but not completely
mastered building technique.

I'd like to think that we have a slightly more refined
sense of megaproject risk analysis now that will prevent
us doing quixotic projects like Dyson spheres.


3. We can barely detect planets the the size of Jupiter around
nearby stars today. Why would we be able to detect non-radiating
dyson spheres? Wouldn't we mistake them for black holes at the
least?

4. The life span of a higher mammal species (clad, actually i.e.
tree of derived species i.e. branch of evolution) like ours is estimated in biology to be 5 to 10 million years,
and we're a significant way through our tenure, so we'd
better hurry up sending out those self-replicating V-ger
robot probes all over the place for them to be detected a million years hence. We'll probably be gone (as a species
and clad) by the time the reply arrives.