Which forces the logical conclusion that this isn't the first such probe, obviously.
The Prime Directive is a mushy human emotional idea, not something that makes any logical sense for a space-faring civilization to follow. If there's any competition out there among space-faring civilizations, none of them are going to tie their hands behind their backs by refusing to touch planets that have native life on them.
And under the Dark Forest, the best way to survive would be to replicate as fast as possible, consuming all available resources. They would want to hide from external, more-powerful civilizations, but they'd have no reason at all to hide from us. Hiding from us would be a strict loss for them, as it means they can't mine Earth for resources.
If there's any competition between civilizations, then it's even more obvious that each one will be racing to claim any star system that isn't already claimed. But even with no competition, it makes sense to spread rapidly.
If you don't find that intuitively obvious, consider this: In 4.5 billion years, the Milky Way will collide with Andromeda. This presents us with a literal galactic-scale single-turn prisoner's dilemma: If intelligent life exists in Andromeda, they may already be preparing to conquer the Milky Way. If they are, and we don't prepare to fight back, they will obviously win. We won't have any ability to communicate with Andromeda to find out their intentions until it's too late. The earlier we start preparing, the more likely we are to survive.
So if I were a spacefaring civilization in the Milky Way today, I'd be doing everything I could to mobilize every star system in the galaxy in preparation to beat Andromeda. There's just no reason not to...
As for fleeing: The whole concept of "fleeing" assumes a civilization composed of discrete beings that are expensive to reproduce but can be feasibly transported. The idea of Von Neumann probes is based on a different assumption. The probe itself is very small, maybe only a few pounds, but is designed to expand using the resources at its destination. There probably aren't discrete beings -- computers can freely exchange "memories" over networks which makes them effectively all one big hive mind. The hive mind directly controls everything it builds. Eventually the entire star system -- perhaps the entire galaxy or universe -- becomes effectively one giant intelligent being as all available resources are assimilated.
This civilization would certainly send probes to neighboring galaxies if it has the ability to, but it makes no sense to think about transporting the "inhabitants" (if you can even call them that) of one star system to another en masse.
Also, the math doesn't work out in the sense that if a species that had this instinct reached interstellar travel a million years ago the Milky Way galaxy would already have entirely been consumed. That's the Fermi Paradox in a nutshell.
If the species you are describing exists, they must have just started eating the galaxy, because the galaxy would already be eaten in an blink of an eye on the cosmic timeline.
Lets suppose that it takes a ten thousand years to reach a star system and consume it, and the swarm needs the resources of an entire star system just to build 2 more probes.
That means that the number of star systems consumed doubles every ten thousand years. At that rate it takes no more than 50 generations, or half a million years, to consume the entire galaxy.
Note that if the number of probes the Von Neumann swarm builds is more than 2 per star system consumed, this process happens even faster.
Have you ever read Issac Asimov's story "The Gentle Vultures"?
This may be an entirely human-centric assumption. Maybe there are a million civilizations out there living in balance with their local planetary environments, entirely without the expansionist curiosity and destructive drive that leads humans to seriously contemplate things like von Neumann probes?
Interstellar civilizations are unlikely to be biological, but evolution still applies. All it takes is for one civilization in the whole galaxy to decide to build Von Neumann probes, and they'll have taken control of all unoccupied systems in the galaxy in short order.
I'm trying to imagine what to do now in preparation for a hostile encounter in 4.5 billion years that isn't already happening organically. By "organically", I mean both "in the course of gradual or natural development" and "w.r.t. living matter", given the time scale.
Do you have ideas?
What’s the evidence that wholesale environmental destruction is a good idea on a galactic scale if it’s already known to be a terrible idea on a planetary scale?
Self-replicating hyper-intelligent artificial beings presumably will be able to redesign themselves to match any target environment.
Note: This is not a moral judgment. I obviously think it would be awful if some AI gray goo consumed the universe and wiped out all the unique forms of life. But I think that's a rather human value and I don't see why the AI would share it.
For this to have happened, it must have happened much less than a million years ago, otherwise your hypothetical civilization would already have easily consumed the entire galaxy.
Since we are still here, if that civilization exists, it must have arrived on the interstellar scene less than one quarter of one tenth of one percent (< 0.025%) of the age of the solar system ago. That seems like a crazy unlikely chance.
This is the fundamental problem with Von Neumann probes / AI grey goo in general : They eat the galaxy way, way faster than anyone can imagine. If they exist, why are we still here?
Earth may be part of what an alien species consider as their territory.
¹ through influencing politicians and the rich and powerful to keep poisoning the Earth with extreme pollution.
https://www.google.com/amp/s/www.indiewire.com/2014/10/john-...
This is imagining that space exploration is done by human-like entities that have discrete physical bodies and slow reproduction rates. They come to a place, check it out, and move on.
AI-driven Von Neumann probes would operate very differently. They arrive, and they settle and replicate. Eventually they send out new probes. But they don't leave once they have arrived. There's never any reason to leave.
Besides, we still routinely fail to spot asteroids until they get close to Earth or pass by.
There may be more dwarf planets like Pluto, or a major planet the size of Neptune (per Caltech researchers, so called Planet Nine or Planet X) in our own solar system and we can't easily find them.
No need to intentionally hide from the primitive humans that are still struggling to locate large objects in their solar system and near their planet.
Maybe after another million years of development a species' main motivation would be simple curiosity, in other words they are basically scientists. Scientists may want to avoid interfering with a species they are studying and therefore remain hidden. But then the same scientists conducting a different experiment may want to selectively perturb the specimen's environment to probe their psychological reactions and degree of intellectual development.
Exactement, le terrien classique (de la norme), fonctionne principalement à l'aide de biais cognitifs et autres syndromes l'empêchant, par cohésion social, à admettre d'autre tunnel de réalité que ceux qui ont composé leurs groupe (majoritaire actuellement) C'est dommage, avec un cerveau si puissant, si vous saviez ce que l'on peux comprendre, en admettant d’omettre la permanente conscience de soi.
There's so much good stuff out in the Oort cloud, why would you ever bother climbing down the gravity well, let alone attacking the poor primitives most of the way down it?
A more likely "War of the worlds" scenario would be someone mining the outer solar system to bits and leaving without us being able to throw so much as a rock at them. If they take enough, even our ability to hunt them down for revenge would be significantly hampered.