> if you've colonized say 20 stars, what disaster could possibly end your civilization?
Unfortunately, war with another civilization.
Unfortunately, war with another civilization.
Like if on Earth nukes were something everyone could cook up in their backyard in an afternoon, we'd all be gone pretty quick.
Not sure that really makes any sense though.
The Killing Star[0] and Flying to Valhalla by Charles Pellegrino are based around the idea that it's natural for a species to annihilate all other sentient species. The characters define three rules that an alien species may be operating by.
Rule 1. Aliens will believe their survival is more important than our survival.
Rule 2. Wimps don't become top dogs.
Rule 3. Aliens will assume that the first two rules apply to us as well.
[0] https://tvtropes.org/pmwiki/pmwiki.php/Literature/TheKilling...
In the book that the OP article is based on, humanity is doing anything and everything to prevent/defend themselves against an alien invasion happening ~400 years in the future. The character who coins "Dark Forest" theory in the book proposes sending a 'spell' (just a signal containing coordinates) to a nearby star, which is then amplified throughout the universe via "Sci-Fi science". This reveals the location of the star, and shortly after the star is destroyed by some comet-sized object moving at the speed of light. It's later revealed that some other civilization listens for broadcasts on every spectrum, decodes them for coordinates, then destroys the ones that seem to have actually been sent by intelligent life.
I thought this made perfect sense - why wouldn't another intelligent species do this if they possess the technology? I personally agree with "Dark Forest" theory and think that we should /never/ make first contact (lest we are destroyed), but if we were to attempt first contact, we should at the very least have a weapon like you described available to us first.
I think the only question we can ask here is "Would we do this if we possessed the technology?". We only have ourselves as an example of intelligent life.
Society probably only functions below a certain level of technological advancement before everybody dies to an onslaught of engineered diseases.
If we can control resource, exchange knowledge and techniques, and reproduce automatically (for instance if we become small electronic machines rather than the current inefficient chemical process we are), "war" might probably sounds both ridiculous and totally ineffective, both to cull us if we're abstract enough, and to cull potential enemies, probably just as impossible to reach "physically".
Perhaps we can shake off many emotional components of war (which would make war an irrational option in many of the cases that our monkey brain would have been dragged into) but that doesn't necessarily mean that war itself would be eradicated
Also, multi-species symbiotic relationships are quite common in the animal kingdom. It would be surprising if that weren't true at other scales (and if it were limited to the sci-fi trope of "worker species, soldier species, leader species").
Selective pressures that permit the emergence of cooperative behaviour require participating individuals to exhibit a variation in behaviour and those who cooperate result in having a higher fitness in the environment than those who shun cooperation. The selection effect operates on over the whole population and over times that are longer than the life span of an individual.
An individual that is implementing what ultimately will emerge as the winning strategy, may on average be better off, but it can (and it will) be also often worse off.
Depending whose existence you're optimizing for (individual or species) changes the framing of what is the optimal strategy.
An existential risk for a species changes the framing of what is rational to do quite a lot.