I read the article. It's not bad.
Here are some thoughts:
Let's say that there's alien civilization "A" that is a mere thousand light years away from us and is technologically capable
of seeing (by some telescopic means) signs of life on Earth (bright lights, atmospheric items in orbit, etc).
So one day they point their sights right at our beautiful pale blue dot.
What will they see?
You guessed it - Earth - a thousand years ago.
Did we have brights lights, big cities, and satellites in orbit a thousand years ago?
Not even close.
If we happen to have pointed a signal at ET on planet "A" travelling at the speed of light (the speed limit as far as we know) they'll get it in the the year 3015.
We've got a while to wait before they send something back. And more time to wait for their response.
It's likely that if an ancient civilization knew of the ideal situations for life on earth, they past us up long ago because there wasn't anything worth waiting around for.
Percolation theory might explain how an alien civilization might have or will migrate.
Davies discusses it briefly in The Eerie Silence:http://en.wikipedia.org/wiki/Percolation_theory
If ET was hostile that threat ended long ago because we missed (luckily) the migration wave.
If migration hasn't happened yet, because it hasn't happened yet probably means the enormous challenges of space and time are too great for whatever is out. If an advanced alien civilization has mastered the hypothetical aspects of worm hole space travel they're likely off doing other things and do not need to target this planet when their are billions and billions of them our there.
That's a good question; who exactly speaks for earth.
I'd say we'd need three people to represent earth: a scientist, a theologian, and a philosopher.
Let's leave the damn politicians out of it.
I have my reasons for picking the 3 that I did.
If by "Active SETI" we mean entirely boldly broadcasting with increase amplification our existence (and of course, our location in the process) I disagree.
SETI needs to better understand how alien life may be vastly different than our form, and SETI would be better off searching for indicators of intelligent life in space.
The Drake equation gets pretty highly speculative as it moves along. It's nearly guess work with nothing to really hand our hats on.
The excitement of EXOPLANETS is nice, but it's being overplayed in the context of the search for intelligent life.
There's a very broad assumption in play here, meaning the assumption that because earth-like conditions exist on a planet, said planet is likely to have spawned intelligent life.
. That's a fallacy.
If life evolved on an Exo, there is no law known to us that predicts intelligence of the kind we are looking for will fill some life niche as it did here on Earth
Frankly, life is probably very rare, and intelligent life astronomically rarer.
The complexity of life is remarkable. The complexity of intelligent life is simply miraculous.
There's no other way to describe it.
Also, our inability to explain the origin of life makes it impossible to explain where it's likely
We can give it a good guess, but that's about it.
That's a good question about techno civilizations. As I've said previously, we don't know what alien technology is.
Predicting its chances of survival is based on what we predict might or might not happen to us; totally anthropocentric.
Also alien science might have led ET off in a totally different direction.
It will always be tempting to place ourselves back in the center of the universe and conceptualize from there.
SETI is trying to hurdle that error.