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I've been wondering what the advantage of von Neumann probes are. Once you have the ability to autonomously construct probes, it seems like it would be easier a

by bnralt 4y ago

I've been wondering what the advantage of von Neumann probes are. Once you have the ability to autonomously construct probes, it seems like it would be easier and faster to mass produce them in one solar system and send them directly to their destinations. For instance, with a von Neumann probe you have to have probes with additional mass for self-replication, have it accelerate halfway to point A, decelerate halfway their, spend time replicating a new probe that will accelerate halfway to point B and then decelerate, then spend time manufacturing a new probe, then have that accelerate halfway from point B to point A, then decelerate the second half of the way, etc. But if you can automate manufacturing, you can just make specialized devices that mass produce probes in one system, and send them directly to their destination, without waiting for the parent probes to stop at all the in between points to do some manufacturing. And the probes are going to be much lighter because they don't need replication devices in them.

tsimionescu 4y ago
The point is that solar systems have tiny amounts of resources when compared against the idea of colonizing an entire galaxy, whereas the concept of a von Neumann probe swarm would have resources proportional to the task. Now, whether that is actually possible in any serious sense is very much in doubt.
- bnralt 4y ago
  There are ~2 x 10^9 stars in the solar system. The mass of earth is 6 x 10^24 kilos, with about 1/3 of that being iron. So even if we're just using the mass of a single celestial object the size of the earth, and only looking at iron alone, that'd be 1,000,000,000,000,000 kilos of iron you could use per star (for reference, this would be the equivalent of ~300 million fully fueled Saturn V's per star). It seems like a single solar system would have enough resources.
  - tsimionescu 4y ago
    I am quite certain that using all of the iron in a single planet's core is well beyond the difficulty of building a self-replicating probe (which itself is well beyond our technical capabilities). Not to mention, such probes are unlikely to be build able from a single metal, and some metals used for advanced electronics are significantly rarer than iron.
    - bnralt 4y ago
      If you want to restrict yourself to the earth's crust, that'd still be ~5,000,000,000,000 kilos of iron you could use per star, or 1,500,000 Saturn V's. And that's just using one planet. Sure, there are rarer metals. But I'm not seeing evidence that the solar system wouldn't have enough of them, and mass mining and manufacturing seems like an far easier way to handle them than individual probes (the probe would have to land on the various planets, manufacture refueling centers to refuel itself to travel around the planet doing geological survey and take off again, build mining centers when it finds the deposits, etc.).
      - YurgenJurgensen 4y ago
        The fact that you're talking about Saturn Vs and landing on planets and taking off again shows that you're considering the wrong paradigm entirely. If you're landing on planets you're already doing it wrong. Atmosphere and gravity wells are the enemy. Remember, even the non-self-replicating probe still needs to be self-repairing, since in your scenario it has to last for probably a million years' worth of radiation and micrometeorite damage. A million years' worth of spare parts is probably a much bigger investment than some automated manufacturing.
        bnralt 4y ago
        I brought up Saturn V's to give people a sense of the mass we're talking about, not because I thought the probes would be actual Saturn V's (and I don't think we'll be sending 1.5 million of them to a single star). As I said, the reason I talked about landing on planets is because you mentioned rare metals, and I don't know how _reliably_ they could be found if you're only looking at asteroids. But maybe that's not an issue.
YurgenJurgensen 4y ago
If the probes don't have replication devices in them, what are they doing? The main point of the von-Neumann strategy is that if you don't build a self-replicating hegemonic swarm object, someone else will (whether that be an alien or merely someone else in your own society), and despite what science fiction movies would like to have you believe, you don't win in a war against the Replicators.
- Hizonner 4y ago
  > if you don't build a self-replicating hegemonic swarm object, someone else will Why do I care?
  - YurgenJurgensen 4y ago
    If you've achieved enlightenment and freedom from all desire, then it's a bit weird that you're posting on Internet forums. If not, presumably you'd quite like to not be turned into a paperclip.
    - Hizonner 4y ago
      Hey, if they can't build a swarm that does something more fun than that, why would I think I could? I mean, my own swarm is subject to value drift and may also clip me.
      - YurgenJurgensen 4y ago
        It doesn't matter that you're unimaginative, only that not everyone is as unimaginative as you.
- m4rtink 4y ago
  You do if yours are better. ;-)
Hizonner 4y ago
To send you back any information, your probe has to either send back something physical or use the electromagnetic spectrum. If you send a probe with no manufacturing capacity, then it either has to carry all the fuel, shielding, and redundancy for both directions of the trip, or carry a very large radio and its much larger power source. That's gonna be really, really heavy. Probably heavier than the manufacturing machinery. So you would want to be able to manufacture just so you could report back. Once you have the manufacturing stuff, you might as well build a bunch more probes. Each generation of will start from the furthest range of the previous generation, with all the knowledge accumulated by its predecessors. A probe with a generalized manufacturing capability can also do other interesting things on station. If it's smart enough, it's more like a colony than a probe... and it would probably have to be that smart anyway. A probe with no manufacturing capability can only report back, and then you have to send something all that way again if you want to do something interesting at the destination. I'm not sure the whole project is worth it, though. And, with very high probability, the reason we haven't seen or heard from anybody isn't that they haven't gotten around to "viewing our Earth television programs" and responding. It's not even that they don't want to talk. It's that there's nobody out there. I don't understand the desperation that leads people to come up with increasingly farfetched ways to hide from that obvious conclusion.
- bnralt 4y ago
  Like you said, if you want it to do "something interesting," like building a colony, we're not talking about probes anymore. But even then, it seems like mass producing the would be faster. Consider - you're clearly going to be getting somewhere faster if you accelerate for 50,000 lightyears and decelerate for 50,000 than if you accelerate for 5, decelerate for 5, build a probe, accelerate for 5, decelerate for 5, build a probe, etc., 10,000 times. In the end you're going to be covering less distance if you go directly (because you're not zig-zagging from star to star), you're going to be reaching a higher maximum velocity (you're going to be accelerating for a longer length of time), and you won't have to wait to manufacture probes along the way.

by bnralt 4y ago

tsimionescu 4y ago

The point is that solar systems have tiny amounts of resources when compared against the idea of colonizing an entire galaxy, whereas the concept of a von Neumann probe swarm would have resources proportional to the task. Now, whether that is actually possible in any serious sense is very much in doubt.

bnralt 4y ago
There are ~2 x 10^9 stars in the solar system. The mass of earth is 6 x 10^24 kilos, with about 1/3 of that being iron. So even if we're just using the mass of a single celestial object the size of the earth, and only looking at iron alone, that'd be 1,000,000,000,000,000 kilos of iron you could use per star (for reference, this would be the equivalent of ~300 million fully fueled Saturn V's per star). It seems like a single solar system would have enough resources.
- tsimionescu 4y ago
  I am quite certain that using all of the iron in a single planet's core is well beyond the difficulty of building a self-replicating probe (which itself is well beyond our technical capabilities). Not to mention, such probes are unlikely to be build able from a single metal, and some metals used for advanced electronics are significantly rarer than iron.
  - bnralt 4y ago
    If you want to restrict yourself to the earth's crust, that'd still be ~5,000,000,000,000 kilos of iron you could use per star, or 1,500,000 Saturn V's. And that's just using one planet. Sure, there are rarer metals. But I'm not seeing evidence that the solar system wouldn't have enough of them, and mass mining and manufacturing seems like an far easier way to handle them than individual probes (the probe would have to land on the various planets, manufacture refueling centers to refuel itself to travel around the planet doing geological survey and take off again, build mining centers when it finds the deposits, etc.).
    - YurgenJurgensen 4y ago
      The fact that you're talking about Saturn Vs and landing on planets and taking off again shows that you're considering the wrong paradigm entirely. If you're landing on planets you're already doing it wrong. Atmosphere and gravity wells are the enemy. Remember, even the non-self-replicating probe still needs to be self-repairing, since in your scenario it has to last for probably a million years' worth of radiation and micrometeorite damage. A million years' worth of spare parts is probably a much bigger investment than some automated manufacturing.
      - bnralt 4y ago
        I brought up Saturn V's to give people a sense of the mass we're talking about, not because I thought the probes would be actual Saturn V's (and I don't think we'll be sending 1.5 million of them to a single star). As I said, the reason I talked about landing on planets is because you mentioned rare metals, and I don't know how _reliably_ they could be found if you're only looking at asteroids. But maybe that's not an issue.

YurgenJurgensen 4y ago

If the probes don't have replication devices in them, what are they doing? The main point of the von-Neumann strategy is that if you don't build a self-replicating hegemonic swarm object, someone else will (whether that be an alien or merely someone else in your own society), and despite what science fiction movies would like to have you believe, you don't win in a war against the Replicators.

Hizonner 4y ago
> if you don't build a self-replicating hegemonic swarm object, someone else will Why do I care?
- YurgenJurgensen 4y ago
  If you've achieved enlightenment and freedom from all desire, then it's a bit weird that you're posting on Internet forums. If not, presumably you'd quite like to not be turned into a paperclip.
  - Hizonner 4y ago
    Hey, if they can't build a swarm that does something more fun than that, why would I think I could? I mean, my own swarm is subject to value drift and may also clip me.
    - YurgenJurgensen 4y ago
      It doesn't matter that you're unimaginative, only that not everyone is as unimaginative as you.
m4rtink 4y ago
You do if yours are better. ;-)

Hizonner 4y ago

To send you back any information, your probe has to either send back something physical or use the electromagnetic spectrum. If you send a probe with no manufacturing capacity, then it either has to carry all the fuel, shielding, and redundancy for both directions of the trip, or carry a very large radio and its much larger power source. That's gonna be really, really heavy. Probably heavier than the manufacturing machinery. So you would want to be able to manufacture just so you could report back. Once you have the manufacturing stuff, you might as well build a bunch more probes. Each generation of will start from the furthest range of the previous generation, with all the knowledge accumulated by its predecessors. A probe with a generalized manufacturing capability can also do other interesting things on station. If it's smart enough, it's more like a colony than a probe... and it would probably have to be that smart anyway. A probe with no manufacturing capability can only report back, and then you have to send something all that way again if you want to do something interesting at the destination. I'm not sure the whole project is worth it, though. And, with very high probability, the reason we haven't seen or heard from anybody isn't that they haven't gotten around to "viewing our Earth television programs" and responding. It's not even that they don't want to talk. It's that there's nobody out there. I don't understand the desperation that leads people to come up with increasingly farfetched ways to hide from that obvious conclusion.

bnralt 4y ago
Like you said, if you want it to do "something interesting," like building a colony, we're not talking about probes anymore. But even then, it seems like mass producing the would be faster. Consider - you're clearly going to be getting somewhere faster if you accelerate for 50,000 lightyears and decelerate for 50,000 than if you accelerate for 5, decelerate for 5, build a probe, accelerate for 5, decelerate for 5, build a probe, etc., 10,000 times. In the end you're going to be covering less distance if you go directly (because you're not zig-zagging from star to star), you're going to be reaching a higher maximum velocity (you're going to be accelerating for a longer length of time), and you won't have to wait to manufacture probes along the way.