[fixedd]

The whole Fermi Paradox thing bugs me too, but in a different way. It assumes we have the capability of detecting the presence of other intelligent life.

The largest radio telescope we have (the 305 meter diameter Arecibo) would need to have it's sensitivity increased by around two orders of magnitude JUST to pick up our TV/FM/AM signals from outside the solar system. If we move into the narrowband signals then, depending on the source-strength, it could pick up signals at up to a few thousand light years... if it happened to be pointed in exactly the right direction at exactly the right time. So, our most sensitive instrument is only capable of measuring a fraction of a percent of a fraction of a percent of the galaxy.

I just straight-up don't believe that we're even remotely approaching the capability of asserting that the galaxy is sterile of higher life that's constantly dumping EM noise... and that's without assuming they've found ways to transmit data that we're ignorant of or that we've seen it and just haven't noticed it.

--

The other thing (and I feel a bit like a religious person saying this) is that we have exactly zero basis for asserting that the type of machine you're talking about haven't been here. Given that if one of these machines came here, and stayed, the Earth itself would annihilate all traces of it (especially on the surface) within short order we shouldn't necessarily expect to find evidence of a visit.

Taken to the extreme, you could even reason that all life on Earth could be the product of one of these machines.

[dhimes]

Not only is sensitivity an issue, but also frequency range. I feel quite confident that more technologically advanced civilizations will communicate at frequencies we are currently unable to demodulate. It's more efficient. Look how our frequencies have scaled on the order of a hundred years.

[swombat]

> Taken to the extreme, you could even reason that all life on Earth could be the product of one of these machines.

Hah, hilariously ironic. "Where is alien life in the universe? Are we the only ones?" continually bemoan the descendants of the organic probe sent to Earth to populate it with intelligent life.