<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>nafey</author><text>What you are missing is that technological advancement can accelerate exponentially. Couple this fact nothing can move faster than light. This means if you don&amp;#x27;t stamp out alien life as soon as you encounter it then the next time you come back they might already have achieved technological parity with you. And they might not be as forgiving as you are. This means you have to hide and you have to exterminate any alien life that knowns about your existence. I do think if oumuamua was an alien probe then we should be gravely concerned.</text><parent_chain><item><author>kentonv</author><text>While it&amp;#x27;s entirely possible they&amp;#x27;d have a good reason to be stealthy, I don&amp;#x27;t think it&amp;#x27;s likely to be anything we&amp;#x27;ve thought of.&lt;p&gt;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&amp;#x27;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.&lt;p&gt;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&amp;#x27;d have no reason at all to hide from &lt;i&gt;us&lt;/i&gt;. Hiding from us would be a strict loss for them, as it means they can&amp;#x27;t mine Earth for resources.</text></item><item><author>throwaway316943</author><text>If the mission of the probe is exploration then it doesn’t need to consume all of the resources of a solar system. It just needs enough to make a few copies to reach the nearest handful of stars. If they are using light sails as propulsion they probably need barely anything. I don’t have a hard time believing that an advanced civilization would choose hiding as the default method of exploration. Anything from the dark forest to the prime directive could be used as an argument to do so. I agree with the other comments that it’s fairly likely that our system has had multiple probes pass through. The unlikely event will be when one decides to contact us.</text></item><item><author>kentonv</author><text>That could only be true if they are intentionally hiding from us, rather than replicating and harvesting the solar system as fast as they can. But personally I have a hard time believing that hyper-intelligent devices would care about avoiding detection by lowly biological organisms like us.</text></item><item><author>jameshart</author><text>Which forces the logical conclusion that this isn&amp;#x27;t the first such probe, obviously.</text></item><item><author>kentonv</author><text>My pet theory (which is not intended to be taken too seriously) is that it is indeed a discarded light sail, and that light sail in particular was used to transport a Von Neumann probe which detached at some point after the object entered our solar system but before we first observed it. This detachment, in addition to leaving the sail tumbling, would have changed its trajectory, meaning our estimation of which direction the object originally came from is incorrect. In any case, the probe is now busy replicating, perhaps on the surface of Mercury. In a few years an army of robots will launch from there and invade the rest of the solar system!&lt;p&gt;Realistically, though, it&amp;#x27;s too much of a coincidence that such a probe would first arrive so soon after we gained the ability to conceive of it.</text></item></parent_chain></comment><story><title>Mystery of interstellar visitor &apos;Oumuamua gets trickier</title><url>https://www.scientificamerican.com/article/mystery-of-interstellar-visitor-oumuamua-gets-trickier/</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>throwaway316943</author><text>I’m not sure that reasoning holds up. There’s no reason to believe that “mushy human emotional ideas” are not the norm. There’s no data to support that claim since humanity is the only example we have of intelligence. So for the sake of the argument I’m going to define alien intelligence as similar to human intelligence. I’d also inquire what the point of having a Von Neumann probe consume all of a system would be? It’s not practical to ship the resources anywhere at sub light speed. There’s a limit on the number of probes it would be rational to make in any one system even if you were going for high redundancy. Even use as a weapon would be foolish since there’s a good chance something could go wrong and you’d wind up killing your own systems. Maybe if you were paving the way for a colony but even then you’d only build what you needed to avoid having to constantly maintain the structures until they were useful. The only way I see an exploitive strategy working is if you have FTL travel and if you have that then Von Neumann probes are useless old technology since you would just send a fleet of ships with what you need to get started rather than trying to bootstrap from a single self replicating probe.</text><parent_chain><item><author>kentonv</author><text>While it&amp;#x27;s entirely possible they&amp;#x27;d have a good reason to be stealthy, I don&amp;#x27;t think it&amp;#x27;s likely to be anything we&amp;#x27;ve thought of.&lt;p&gt;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&amp;#x27;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.&lt;p&gt;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&amp;#x27;d have no reason at all to hide from &lt;i&gt;us&lt;/i&gt;. Hiding from us would be a strict loss for them, as it means they can&amp;#x27;t mine Earth for resources.</text></item><item><author>throwaway316943</author><text>If the mission of the probe is exploration then it doesn’t need to consume all of the resources of a solar system. It just needs enough to make a few copies to reach the nearest handful of stars. If they are using light sails as propulsion they probably need barely anything. I don’t have a hard time believing that an advanced civilization would choose hiding as the default method of exploration. Anything from the dark forest to the prime directive could be used as an argument to do so. I agree with the other comments that it’s fairly likely that our system has had multiple probes pass through. The unlikely event will be when one decides to contact us.</text></item><item><author>kentonv</author><text>That could only be true if they are intentionally hiding from us, rather than replicating and harvesting the solar system as fast as they can. But personally I have a hard time believing that hyper-intelligent devices would care about avoiding detection by lowly biological organisms like us.</text></item><item><author>jameshart</author><text>Which forces the logical conclusion that this isn&amp;#x27;t the first such probe, obviously.</text></item><item><author>kentonv</author><text>My pet theory (which is not intended to be taken too seriously) is that it is indeed a discarded light sail, and that light sail in particular was used to transport a Von Neumann probe which detached at some point after the object entered our solar system but before we first observed it. This detachment, in addition to leaving the sail tumbling, would have changed its trajectory, meaning our estimation of which direction the object originally came from is incorrect. In any case, the probe is now busy replicating, perhaps on the surface of Mercury. In a few years an army of robots will launch from there and invade the rest of the solar system!&lt;p&gt;Realistically, though, it&amp;#x27;s too much of a coincidence that such a probe would first arrive so soon after we gained the ability to conceive of it.</text></item></parent_chain></comment><story><title>Mystery of interstellar visitor &apos;Oumuamua gets trickier</title><url>https://www.scientificamerican.com/article/mystery-of-interstellar-visitor-oumuamua-gets-trickier/</url></story>