I've pointed it out before, not that anyone remembers
it, assuming they ever read it but, the earth is
constantly bombarded with alien signals.
Constantly.
The universe is so vast, the time scales are so
phenomenally huge it's impossible that countless
civilizations haven't arisen.
Many? Most? Quite a lot of them, and probably most,
are already extinct. But their signals are still
reaching us. Constantly. From every direction.
We can't detect them though.
For us, alien signals are akin to microbial life in
the days before the microscope was invented. Even if
we're certain that they're there, we can't see them.
We can't detect them.
I've seen it claimed that our broadcasts signals
wouldn't even be readable on the surface of Proxima
Centauri, given our technology. Move our dishes to
Proxima Centauri, point them towards earth and you
are NOT going to be watching Seinfeld re-runs...
Anyone old enough to remember rabbit ear antennas?
Now imagine ten or 100 or 10 thousand light years
away. Or a billion light years away. Or 5 billion.
Most of the universe is EXTREMELY far away from us.
Seeing how we don't actually know the rules, if any,
for the development of life & higher civilizations,
we've got to assume a fairly uniform distribution.
Meaning, it's just as likely to form billions of
light years away from us as it was to form right
here.
The universe is so vast, the overwhelming super
majority of any civilizations to arise would originate
so very far away from us that their signals would be
totally undetectable. Perhaps they are so weak, so
degraded that they could NEVER be readable.
But...
Imagine if a spy could sit in downtown Moscow and
broadcast a signal -- perhaps even live video --
that was undetectable by the Russians, it was so
weak?
That's the sort of thing humanity might try to sell
to the Pentagon; the technology needed to hunt for
aliens would have national security benefits.
Cha-Ching!
So there is hope. Our darkest nature may be our
brightest hope, in this regard.
-- https://jtem.tumblr.com/tagged/The%20Book%20of%20JTEM/page/5
Aliens! Omg, ALIENS!