I think they're counting upon an advanced civilization sending out a "beacon" signal of some sort. The implication is they have the energy to use for that, and the interest.

What I find interesting is the way technologically advanced human civilizations have treated less advanced peoples. It's been uninterrupted domination, slaughter, and so on.

Therefore, I suspect an "advanced" civilization would know that, and not want to be found. Therefore wouldn't expend the energy on a beacon.

And I think that humanity regards itself as so charming and likeable that anyone finding us would take the whole place under it's wing, teach us the secret of everlasting life and faster-than-light-travel, etc.

I suspect they'd regard us the way we do ants where we want to pave.

I wonder what it would be like if we did contact folks 88 light years away. After they sent a signal saying they'd drop by in a while, what would we do? We'd have to assume they would arrive not long after their signal.

Interesting conjecture.

Arf