The Great Filter is the idea that, in the development of life from the earliest stages of abiogenesis to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare. The Great Filter is one possible resolution of the Fermi paradox.
https://en.wikipedia.org/wiki/Great_Filter
The Fermi paradox is the discrepancy between the lack of conclusive evidence of advanced extraterrestrial life and the apparently high likelihood of its existence. As a 2015 article put it, “If life is so easy, someone from somewhere must have come calling by now.”
https://en.wikipedia.org/wiki/Fermi_paradox
Personally I think it’s photosynthesis. Life itself developed and spread but photosynthesis started an inevitable chain of ever-greater and more-efficient life. I think a random chain of mutations that turns carbon-based proto-life into something that can harvest light energy is wildly unlikely, even after the wildly unlikely event of life beginning in the first place.
I have no data to back that up, just a guess.
The galaxy is a bowl of M&Ms. One of every hundred M&Ms is poisoned and will immediately kill you. It’s only a 1% chance you’ll die. Well maybe pike 5% if you eat a handful.
Most of the civilizations might even be moral enough not to destroy us, but all it takes is one.
How do they do it, though? It’s not really a valid solution unless you can explain how it works, otherwise it’s just “maybe some magic happens that kills civilizations.”
Once a civilization has begun spreading to hundreds of other solar systems I have yet to hear of any plausible way to reliably “kill” it.
Guns? Bombs? Surely you can kill a civilization. Not sure why magic would be required.
I don’t think you’ve thought through the logistics required for the sort of war where you’d just go around and shoot everyone who lives in hundreds of solar systems. Even assuming they do nothing at all to defend themselves, how do you even find them all?
Yep exactly. Who knows how murderous other civs might be, maybe they’re nice but maybe not.