Von Neumanns

[Evo Plurion]

In his novels "Cold As Ice", "Ganymede Club" and "Dark As Day", Charles Sheffield describes self-replicating automota named for the Hungarian mathematician John von Neumann. They are used to extract fuel from gas giants, excavate underground habitats, etc. They are completely self-sufficient, using local materials not only for fuel, but for building more Von Neumanns as well.

Anyhow, they could have great application in a Traveller setting. Anyone use them?

 

[FlightCommanderSolitude]

Dan Simmons' novel Ilium presents a "race" of cybernetic machines called, humorously, moravecs.

 

[ScottB]

I use them as bad guys. In the spirit of Greg Bear's "Forge of God" (and probably lots of other sources), von Neumann machines are often used by less than ethical civilizations that want to make sure no other advanced competitors arise in their neighbourhood. So they send out von Neumann machines that listen for SETI-style signals from systems likely to have habitable planets, home in on the planets, and consume them (along with the eager 1930-2000ish level civilization that produced the signals).

I also use the idea that AIs, once put in charge of their own design, might be able to improve themselves beyond the ability of their creators to control (or even comprehend). So the von Neumanns running around after a few millenia tend to be pretty scary. The threat fills the same slot in MTU as Virus or Star Trek's Borg, but perhaps a bit scarier since they don't want you or your equipment - just that rock you're standing on.

 

[Spiderfish]

Reminds of those things that I read about in a guide to Star Wars vehicles.

World Eaters/Destroyers I think they were called big self replicating automated fatories that slowly "ate" planets and churned out weapons.

I think they might have been called world devastators actually.

Is Forge of God the one when Earth is sort of "destroyed"?

 

[ScottB]

Originally posted by Spiderfish:
Is Forge of God the one when Earth is sort of "destroyed"?

Hmm, that would be spoiling!

Oh, all right. Yes, it is, except for the "sort of" part.

 

[vutpakdi]

There is a very good David Brin short story based on the premise that the only way civilizations can explore and expand is through robotic probes and that humans are very late on the scene. Eventually, a number of these probes, many ancient, and half destroyed, collect on a moon around Jupiter where, eventually, humans find evidence of them. The surviving probes debate contacting the humans. Part of the reason that the probes have stayed silent for so long is that there are different camps or groups of probes. Some that are out to contact and explore while others are only out to destroy any rival civilizations. The probes around Jupiter don't want to draw attention to the humans and cause the destroyer type probes to notice that something has developed on Earth enough to be threat.

Ron

 

[Malenfant]

The monoliths in the 2001 series (esp. 2010) are Von Neumann machines, iirc. They replicate in the same way when they turn Jupiter into a star anyway.

 

[alanb]

Of course, real life Von Neumann machines are called biological organisms.

If you want ones that aren't carbon based lifeforms, feel free.

 

[Malenfant]

AFAIK, Von Neumann machines are those that replicate exponentially. So an example would be something that makes two copies of itself, and each of those splits into two, and so on. So you start with 1 thing, then you have 2, then 4, then 8, then 16, etc.

Are there any biological organisms that do that? All I can think of are viruses and bacteria.

 

[alanb]

Originally posted by Malenfant:
AFAIK, Von Neumann machines are those that replicate exponentially. So an example would be something that makes two copies of itself, and each of those splits into two, and so on. So you start with 1 thing, then you have 2, then 4, then 8, then 16, etc.

Are there any biological organisms that do that? All I can think of are viruses and bacteria.

I'm not sure that that is part of the definition, but in any case biological organisms in general _can_ do that.

First of all, of course, where you have two sexes, your unit is a reproducing pair, rather than a single individual. That's no problem, conceptually. The actual structure of a Von Neumann machine is irrelevant at a logical/conceptual level.

So: a single pair can have four offspring (two reproducing pairs). Each of these can have four offspring, and so on. So the exponential effect still exists.

Now, of course, there can be errors in reproduction - mutation, not to mention problems of inbreeding(!) - but these are not obstacles at the abstract level.

Of course, any Von Neumann system will eventually run up against limits of energy and raw materials, and that applies to both biological systems and non-biological ones. So your exponential growth will eventually peak in a given context. Unless the population can colonise new areas...

Incidentally, your Von Neumann machines aren't inherently limited to only two copies, either, so your growth may actually be faster than the 2, 4, 8, ... sequence.

All good fun.

 

[mike wightman]

This topic reminds me of those mechanical insect-like replicators in Stargate.

By the way, how big are these Von Neumann machines supposed to be and how are they powered (in the novels)?

 

[Ben W Bell]

Originally posted by Malenfant:
Are there any biological organisms that do that? All I can think of are viruses and bacteria.

Well kind of. A human fertilised egg is like this. Goes from single cell to 2, to 4, to 8 to 16 etc as it grows and matures.

 

[ScottB]

I believe the strict definition of a von Neumann machine (at least so far as interstellar probes go) is a machine that can make an exact replica of itself. Humans wouldn't really count, since we're imperfect replicators, unless you were talking about clones.

Originally posted by Sigg Oddra:
By the way, how big are these Von Neumann machines supposed to be and how are they powered (in the novels)?

In different works of fiction, they can vary in size from nanomachines to huge ships. It all depends on what the author needs them to do.

 

[alanb]

Oh well, biological systems are _imperfect_ Von Neumann machines.

We're getting into pretty fine details of an abstract model here.

Of course, the abstraction is actually an imperfect description of an actually existing phenomenon! That is, biological systems exist, and Von Neumann machines are an idealised model that contains many of their attributes.

In a real sense, nature is right and Von Neumann is wrong.

 

[Evo Plurion]

Originally posted by alanb:
In a real sense, nature is right and Von Neumann is wrong.

Ah, but was Von Neumann not a creature of nature? Were all his ideas and creations not products of nature?

Sorry - I can never resist an opportunity to converse on a philosphical level. Thanks, alanb!

 

[ScottB]

Originally posted by alanb:
In a real sense, nature is right and Von Neumann is wrong.

Well, certainly - von Neumann's intention was to define categories of machines that would mimic some characteristics of living beings (another class of von Neumann machine, that which stores it's own instructions, is simply a computer). My mild objection to referring to humans (or other critters) as von Neumann machines is that it misses some of the intent - the machine is purpose-built for some task and is missing many characteristics of living beings. Referring to humans as a type of von Neumann machine is like referring to humans as a type of animal - probably accurate, but not especially descriptive.

From a narrative standpoint, I like it if hearing that a von Neumann machine jumped insystem evokes the image of some uncaring machine that will do whatever it's programmed to do regardless of what anybody in the way wants. Expanding the terminology to include basically anything that travels between systems dilutes that image enough that it's worth avoiding that sort of broad definition, IMHO, regardless of technical accuracy.

 

[alanb]

True. The killer robot swarm has its amusement value.

One last thought though: the imperfect replicator does have one advantage - it can adapt/evolve. The perfect replicator could potentially find itself in an environment it is unable to deal with, or is at least not optimally suited for.

So a perfect killer robot might actually be an imperfect replicator!

All good silliness.

Just make sure nobody mentions V*rus, and we're fine.

 

[Spiderfish]

VIRUS!

Had to be done alanb.

I find the idea of automonous killer robot probes to be very interesting.