In my group at least half of these don’t count as weird at all. Yet I had never thought of this one, “They’re All Hanging Out At the Edge of the Galaxy”:
This interesting solution to the Fermi Paradox was posited by Milan M. Ćirković and Robert Bradbury.
“We suggest that the outer regions of the Galactic disk are the most likely locations for advanced SETI targets,” they wrote. The reason for this is that sophisticated intelligent communities will tend to migrate outward through the Galaxy as their capacities of information-processing increase. Why? Because machine-based civilizations, with their massive supercomputers, will have huge problems managing their heat waste. They’ll have to set up camp where it’s super cool. And the outer rim of the Galaxy is exactly that.
Subsequently, there may be a different galactic habitable zone for post-Singularity ETIs than for meat-based life. By consequence, advanced ETIs have no interest in exploring the bio-friendly habitable zone. Which means we’re looking for ET in the wrong place. Interestingly, Stephen Wolfram once told me that heat-free computing will someday be possible, so he doesn’t think this is a plausible solution to the Fermi Paradox.