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The Dark Forest is a fun idea but sounds so clearly illogical to me for so many reasons: 1. The cost of interstellar travel is so obscenely high that the threa

by vecter 4y ago

The Dark Forest is a fun idea but sounds so clearly illogical to me for so many reasons: 1. The cost of interstellar travel is so obscenely high that the threat posed by the discovery of an alien species on their home planet would be so miniscule to us and them 2. The cost of remotely annihilating an entire species is so absurdly high as to be obviously impractical and basically impossible. [Spoiler alert] The Dark Forest by Liu Cixin renders all of this irrelevant by the use of science fiction: it purports the existence of interstellar world-destroying weapons that any lowly member of a species can casually "flick" at a "star plucker" to obliterate them. That is not how physics or reality works. We don't even send our trash to space because just getting it out of Earth's orbit is so ridiculously expensive, yet we're thinking about sending enough explosives to destroy an entire civilization some 100+ light-years away?

ericb 4y ago
We've already been sent the world destroying bomb. It is an information bomb built on tragedy of the commons to ensure we overheat our planet before we become interplanetary. Its name is Bitcoin.
sophacles 4y ago
Interesting that you assume physics and engineering are "done" and that there are no unknowns, and that there are no new inventions that will happen moving forward. I don't know any physicists or engineers who believe any such thing. 500 years ago your argument would have been: We cant even get to china in 12 weeks without considerable danger and expense, and you expect me to believe its routine for peasants to do so in 12 hours? That anyone can make a near perfect painting and send it to anyone else no matter where they are in a heartbeat - we don't even make bad paintings of anyone who isn't extremely rich because of the absurd expense of it.
- vecter 4y ago
  I did not assume that "physics and engineering are 'done'". I assume instead that the known laws of physics which seem to prevent faster-than-light travel hold and are inviolable, despite how smart any species may be. The analogy with the the argument 500 years ago doesn't apply because 500 years ago we did not have the understanding of physics and chemistry that we have today. Of course we still have a lot of physics left to discover, but it's extremely unlikely that whatever new physics we discover will violate special relativity.
  - postalrat 4y ago
    You don't need faster than light travel to cover the entire galaxy. Using it as a roadblock doesn't make sense.
    - vecter 4y ago
      It does when traveling interstellar distances. Even traveling at 10% the speed of light, it would take a ship one million years to cross the galaxy. The energy required to accelerate to that speed (and then decelerate to rest) is absurdly high. Once you realize how large the costs become for interstellar travel, simple economics makes most of these arguments moot. The outcome is not worth the cost for almost anything you want to achieve.
      - postalrat 4y ago
        We are about 30k light years from the center and the milky way radius is about 50k light years. So if we sent out probes in every direction we could hit 100% of the galaxy in 800k years. A 100kg probe at 10% of the speed of light is about the energy of a 20 megaton nuke. Another 20 megatons to slow it down. It seems very likely that the technology necessary will be developed in the next 100-10,000 years.
        vecter 4y ago
        Let's say we send 10,000 probes out, each weighing 1,000kg at 10% the speed of light out into the Milky Way. We would do this with the sole intention of destroying an entire planet once we find any hint of even bacterial life? There isn't enough time to phone home to decide what to do with this information, so the probe would have to decide for itself whether or not to commit immediate genocide. How could any government possibly convince their citizens that this is the best use of trillions of tax dollars (if not quadrillions of dollars), not to mention how can we create a 1,000kg device that can categorically annihilate an entire planet? If the Dark Forest theory is indeed true, why haven't we seen evidence of such galactic levels of destruction? The Milky Way has been around for over 10 billion years. Surely by then there must've been at least one civilization advanced enough to do this in that time. Yet we see no evidence for this whatsoever. The more you spell this out, the more absurd it becomes from any practical perspective.
oblak 4y ago
I guess enough time has passed since major Carter blew up a sun, since people are no longer talking about it
rcoveson 4y ago
Are you arguing that advances in science that would look like impossible magic to us today are confined to fiction forever? Why do you believe that (1) and (2) are true at every stage of technological advancement in our distant future, which may be the technological present of our galactic peers? A handful of people today can casually "flick" entire cities out of existence, and enough such flicks could eradicate our species, and even if not it would certainly eradicate many. That would have been an absurd notion to somebody a thousand years ago. But the idea that we'll be able to destroy stars just as easily in a million years is somehow just fiction?
- vecter 4y ago
  No, I am simply arguing that FTL travel is extremely unlikely since whatever physics we discover in the future will almost certainly not overturn special relativity. This thinking along the lines of "things in the past that were believed to be impossible are now possible, therefore things in the future that we now believe impossible may actually happen" is pretty poor reasoning. In the past, our understanding of the fundamental laws of physics was quite lacking. Today, although it is incomplete, our understanding of physics is considerably more advanced to preclude a lot of physically impossible things.
  - rcoveson 4y ago
    > In the past, our understanding of the fundamental laws of physics was quite lacking. Today, although it is incomplete, our understanding of physics is considerably more advanced to preclude a lot of physically impossible things. To me this just sound like a combination of hubris and lack of imagination. Sure, our understanding of physics advanced so much in the last few centuries. Relatively. I'm sure we're at least like 20% of the way towards cracking the puzzle of how the whole universe actually works; there's just some kinks to work out, right? /s The way I view history, in a thousand years everything we "know" now might look like nothing more than once-useful, semi-accurate models for describing the behavior of a tiny little subsystem of what reality actually is. Or, more likely, we won't even remeber why the models of today were ever useful, and the average person (assuming there are still separete "people") will flippantly refer to the scientists of today idiots.
unsupp0rted 4y ago
> the threat posed by the discovery of an alien species on their home planet would be so miniscule That species, left unchecked, could fill up its galaxy in the blink of an eye, by galactic timescales.
idiotsecant 4y ago
We aren't considering anything in light of what we're capable of. We're considering it through the lens of a civilization hundreds, thousands, millions of years more advanced than us. For such a civilization, I think talking about the 'cost' of things is somewhat of an abstract idea because advanced automation is surely possible for them. Once I am capable of producing a self-replicating machine capable of strong-AI level cognition all I have to do is release one at the frontier of my empire, instruct it to seed itself as widely as it can, build up massive stockpiles of processed resources and energy, and await further instructions. Such a network would be capable of nearly arbitrary levels of resource utilization, all of which could be redirected into wiping out my cosmic neighbors, since my species's immediate needs are satisfied by a similar post-scarcity system. If I am capable of such a thing and I choose not to employ the strategy of ruthlessly exterminating all life of which I am aware I run the risk of someone else developing this technology and doing the same to me. The only possible scenario where this doesn't hold water is if it's somehow advantageous to long-term survival of both parties to cooperate and exchange technology rather than spend resources annihilating each other. I think even the simplest game theory analysis will tell us that can't possibly be true.
- vecter 4y ago
  > The only possible scenario where this doesn't hold water There are way too many assumptions baked into what you wrote to make that the only possible scenario where the Dark Forest is incorrect. You basically assume that the benefits of this outweigh the costs, which is entirely unfounded. You also assume that the technology for this is possible. Just saying "imagine something millions (heck I'll give you billions given how old the Milky Way is) of years more advanced than us" does not logically necessitate any of these assumptions to be true. And if the Dark Forest is so obviously true, why hasn't it happened yet? Why are we still alive? For a 10 billion year-old galaxy, you'd imagine there's at least one other sentient species out there capable of such technology (if such technology is even ever possible in this universe, which is not yet proven of course). If you believe in the Dark Forest, then you must be indiscriminate about your killing, since one key tenet of the theory is technological explosion. A hairy ape (or even a small rodent) today may be harmless but given millions of years, could be the most intelligent species in the galaxy. So taking this to its logical end would require you to kill all life (even bacteria) whenever it's detected.
Pigalowda 4y ago
I don’t know if I like either one of your points. For #2 you can find an analogy with nuclear weapons. It would seem trivially presently to use them while ignoring how hard it was to invent and produce them. What if the risk of allowing another alien species to progress is so absurdly high that vast resources are allocated to create WMD to annihilate them. Then it does become trivially easy unless there’s a MAD/detente system. That’s pretty much the point of the book.

by vecter 4y ago

ericb 4y ago

We've already been sent the world destroying bomb. It is an information bomb built on tragedy of the commons to ensure we overheat our planet before we become interplanetary. Its name is Bitcoin.

sophacles 4y ago

Interesting that you assume physics and engineering are "done" and that there are no unknowns, and that there are no new inventions that will happen moving forward. I don't know any physicists or engineers who believe any such thing. 500 years ago your argument would have been: We cant even get to china in 12 weeks without considerable danger and expense, and you expect me to believe its routine for peasants to do so in 12 hours? That anyone can make a near perfect painting and send it to anyone else no matter where they are in a heartbeat - we don't even make bad paintings of anyone who isn't extremely rich because of the absurd expense of it.

vecter 4y ago
I did not assume that "physics and engineering are 'done'". I assume instead that the known laws of physics which seem to prevent faster-than-light travel hold and are inviolable, despite how smart any species may be. The analogy with the the argument 500 years ago doesn't apply because 500 years ago we did not have the understanding of physics and chemistry that we have today. Of course we still have a lot of physics left to discover, but it's extremely unlikely that whatever new physics we discover will violate special relativity.
- postalrat 4y ago
  You don't need faster than light travel to cover the entire galaxy. Using it as a roadblock doesn't make sense.
  - vecter 4y ago
    It does when traveling interstellar distances. Even traveling at 10% the speed of light, it would take a ship one million years to cross the galaxy. The energy required to accelerate to that speed (and then decelerate to rest) is absurdly high. Once you realize how large the costs become for interstellar travel, simple economics makes most of these arguments moot. The outcome is not worth the cost for almost anything you want to achieve.
    - postalrat 4y ago
      We are about 30k light years from the center and the milky way radius is about 50k light years. So if we sent out probes in every direction we could hit 100% of the galaxy in 800k years. A 100kg probe at 10% of the speed of light is about the energy of a 20 megaton nuke. Another 20 megatons to slow it down. It seems very likely that the technology necessary will be developed in the next 100-10,000 years.
      - vecter 4y ago
        Let's say we send 10,000 probes out, each weighing 1,000kg at 10% the speed of light out into the Milky Way. We would do this with the sole intention of destroying an entire planet once we find any hint of even bacterial life? There isn't enough time to phone home to decide what to do with this information, so the probe would have to decide for itself whether or not to commit immediate genocide. How could any government possibly convince their citizens that this is the best use of trillions of tax dollars (if not quadrillions of dollars), not to mention how can we create a 1,000kg device that can categorically annihilate an entire planet? If the Dark Forest theory is indeed true, why haven't we seen evidence of such galactic levels of destruction? The Milky Way has been around for over 10 billion years. Surely by then there must've been at least one civilization advanced enough to do this in that time. Yet we see no evidence for this whatsoever. The more you spell this out, the more absurd it becomes from any practical perspective.

oblak 4y ago

I guess enough time has passed since major Carter blew up a sun, since people are no longer talking about it

rcoveson 4y ago

Are you arguing that advances in science that would look like impossible magic to us today are confined to fiction forever? Why do you believe that (1) and (2) are true at every stage of technological advancement in our distant future, which may be the technological present of our galactic peers? A handful of people today can casually "flick" entire cities out of existence, and enough such flicks could eradicate our species, and even if not it would certainly eradicate many. That would have been an absurd notion to somebody a thousand years ago. But the idea that we'll be able to destroy stars just as easily in a million years is somehow just fiction?

vecter 4y ago
No, I am simply arguing that FTL travel is extremely unlikely since whatever physics we discover in the future will almost certainly not overturn special relativity. This thinking along the lines of "things in the past that were believed to be impossible are now possible, therefore things in the future that we now believe impossible may actually happen" is pretty poor reasoning. In the past, our understanding of the fundamental laws of physics was quite lacking. Today, although it is incomplete, our understanding of physics is considerably more advanced to preclude a lot of physically impossible things.
- rcoveson 4y ago
  > In the past, our understanding of the fundamental laws of physics was quite lacking. Today, although it is incomplete, our understanding of physics is considerably more advanced to preclude a lot of physically impossible things. To me this just sound like a combination of hubris and lack of imagination. Sure, our understanding of physics advanced so much in the last few centuries. Relatively. I'm sure we're at least like 20% of the way towards cracking the puzzle of how the whole universe actually works; there's just some kinks to work out, right? /s The way I view history, in a thousand years everything we "know" now might look like nothing more than once-useful, semi-accurate models for describing the behavior of a tiny little subsystem of what reality actually is. Or, more likely, we won't even remeber why the models of today were ever useful, and the average person (assuming there are still separete "people") will flippantly refer to the scientists of today idiots.

unsupp0rted 4y ago

> the threat posed by the discovery of an alien species on their home planet would be so miniscule That species, left unchecked, could fill up its galaxy in the blink of an eye, by galactic timescales.

idiotsecant 4y ago

We aren't considering anything in light of what we're capable of. We're considering it through the lens of a civilization hundreds, thousands, millions of years more advanced than us. For such a civilization, I think talking about the 'cost' of things is somewhat of an abstract idea because advanced automation is surely possible for them. Once I am capable of producing a self-replicating machine capable of strong-AI level cognition all I have to do is release one at the frontier of my empire, instruct it to seed itself as widely as it can, build up massive stockpiles of processed resources and energy, and await further instructions. Such a network would be capable of nearly arbitrary levels of resource utilization, all of which could be redirected into wiping out my cosmic neighbors, since my species's immediate needs are satisfied by a similar post-scarcity system. If I am capable of such a thing and I choose not to employ the strategy of ruthlessly exterminating all life of which I am aware I run the risk of someone else developing this technology and doing the same to me. The only possible scenario where this doesn't hold water is if it's somehow advantageous to long-term survival of both parties to cooperate and exchange technology rather than spend resources annihilating each other. I think even the simplest game theory analysis will tell us that can't possibly be true.

vecter 4y ago
> The only possible scenario where this doesn't hold water There are way too many assumptions baked into what you wrote to make that the only possible scenario where the Dark Forest is incorrect. You basically assume that the benefits of this outweigh the costs, which is entirely unfounded. You also assume that the technology for this is possible. Just saying "imagine something millions (heck I'll give you billions given how old the Milky Way is) of years more advanced than us" does not logically necessitate any of these assumptions to be true. And if the Dark Forest is so obviously true, why hasn't it happened yet? Why are we still alive? For a 10 billion year-old galaxy, you'd imagine there's at least one other sentient species out there capable of such technology (if such technology is even ever possible in this universe, which is not yet proven of course). If you believe in the Dark Forest, then you must be indiscriminate about your killing, since one key tenet of the theory is technological explosion. A hairy ape (or even a small rodent) today may be harmless but given millions of years, could be the most intelligent species in the galaxy. So taking this to its logical end would require you to kill all life (even bacteria) whenever it's detected.

Pigalowda 4y ago

I don’t know if I like either one of your points. For #2 you can find an analogy with nuclear weapons. It would seem trivially presently to use them while ignoring how hard it was to invent and produce them. What if the risk of allowing another alien species to progress is so absurdly high that vast resources are allocated to create WMD to annihilate them. Then it does become trivially easy unless there’s a MAD/detente system. That’s pretty much the point of the book.