Von Neumann probes

[Souper]

I've been having a massive interest in those things for a while now. Such self-reproduction could make possible what we thought forever to be absolutely impossible. We once thought that exploring all of space was absolutely, un-doable until Mr. Neumann came along and brought forth this proposal, and i have many, many things to discuss about them indeed.

When will lil' old Humanity start building these things?

What are the ups and downs, possibility of extinction or EXTREMELY rapid expansion?

What if they evolve?

What if a Von Neumann probe replicates a sentient iteration? What would that sentient individual probe do? Would it make a civilization? Would it / they try to locate its creators?

Personally, i think in SpaceEngine, a Von Neumann probe that gained sentience is what you are, and the civilisation that built you is either gone, extinct or has passed beyond the bounds of time and space itself.

[Nothalogh]

Humans are the Von Neumann probes, carried by generation ships

[Camacha]

What are the ups and downs, possibility of extinction or EXTREMELY rapid expansion?

A downside is that you might replace the entire universe with probes.

[Souper]

Oh, i was just thinking that. Humans have a drive to explore that can't be ignored, and they reproduce. But then again, humans are made of weak, yielding flesh.

[SargeRho]

A downside is that you might replace the entire universe with probes.

That's kinda the plot of Gray Goo.

[Camacha]

That's kinda the plot of Gray Goo.

I thought of it first. Oh, by the way, causality is a sham.

[AngelLestat]

Few years or months after we reach the singularity (which may be trigger by a hard IA birth).

BUt not sure if it will have any point at that point.

[Bill Phil]

Humans are the Von Neumann probes, carried by generation ships

We're not self replicating... We create anatomically similar copies, but they are genetically different. And two people of the opposite gender are required.

[SargeRho]

We are capable of self-replication, in theory. It takes technology, but since a generation ship is also technology, I think that can be forgiven in this case

[YNM]

Limitations will be the amount of materials. Also, space is huge. Some Von Neumann probes will need to shed parts of itself to go to the next object... It's impossible to fill the universe with them to a significant amount, as most is empty space already.

[AngelLestat]

you can not fill the universe, also there is not point in that, but you can have millions for each star in case the probes has not limits.

Also you can not reach all, the universe is expanding faster than light and there is always more from what we see.

But it can be very bad for the life of all close galaxies.

Of course another intelligence can create a new type of Von Neumann probes just to eliminate these Von Neumann probes.

But as I said, maybe nothing of that has a point when we (or an AI) reach the that tech level... the singularity.. Nothing can be predicted beyond that point, there is not logic path, because it will not be our logic as we know it.

Edited August 1, 2015 by AngelLestat

[magnemoe]

That's kinda the plot of Gray Goo.

Grey goo is an nano-scale replicator, much like cells are, it will face much of the same problems as life has. You are limited to solar or chemical energy. You will be limited by energy or raw materials and you will need all the raw materials at one place.

An Von Newman probe would be more like an industrial process.

The probe would have some fabrication potential and might cannibalize itself for raw materials until it get mining up and running.

First you would make some mining robots and the mining infrastructure. You will also need larger scale construction and assembly facilities.

My guess is that you would scale up in multiple steps before making the new interstellar probe.

Now an bug here is very unlikely to mass produce starships who will mass produce themselves.

Plausible worst case scenario is that it uses all the solar system resources making more mining probes or other parts.

its much easier for grey goo to get out of control, simply in the replicate limitation fails, however it would still be stuck with the resource limitations, no life has replication limits after all.

Cancer is an internal self replication bug, it works as it uses the body's resources and worst case scenario is that you die.

[ZetaX]

Cancer is an internal self replication bug, it works as it uses the body's resources and worst case scenario is that you die.

Well...

[Kibble]

We're not self replicating...

Good point - Von Neumann probes should reproduce sexually!

The problem with interstellar travel is that it takes a really long time, but things don't last very long. Without constant maintenance, something as complex and intricate as a human being, spacecraft, automobile, or modern house only remain functional for a maximum of around 30 years. That's why living things reproduce and die! So Von Neumanns should be launched with a big chunk of raw resources (like Ceres!) to live, reproduce, and die on during the journey to another star.

[ZetaX]

Good point - Von Neumann probes should reproduce sexually!

The problem with interstellar travel is that it takes a really long time, but things don't last very long. Without constant maintenance, something as complex and intricate as a human being, spacecraft, automobile, or modern house only remain functional for a maximum of around 30 years. That's why living things reproduce and die! So Von Neumanns should be launched with a big chunk of raw resources (like Ceres!) to live, reproduce, and die on during the journey to another star.

No, living things reproduce and die because of evolution, i.e. a driving force for change and especially adaption. Houses only require maintainance due to weather, humidity and all the pesky life forms; all those vanish in space. Instead, you get radiation and micrometeorites, both of which are not that hard to shield if mass is no concern.

[Jouni]

I kind of believe that von Neumann machines are impossible. Not only physically impossible, but also logically impossible. I guess they're one of those science fiction ideas that sound too easy to be true.

All evidence so far suggests that (self-) replication is only possible in a system much more complex than the replicated object. In other words, if you want to create a complex machine, you must start with an even more complex machine. Or wait until evolution manages to create an ecosystem complex enough to create the machine.

[andrewas]

And yet, humans manage to produce objects of equal complexity. Producing identical clones would be no harder, its just that evolution favours sexual reproduction with each individual being slightly different.

[ZetaX]

All evidence so far suggests that (self-) replication is only possible in a system much more complex than the replicated object. In other words, if you want to create a complex machine, you must start with an even more complex machine. Or wait until evolution manages to create an ecosystem complex enough to create the machine.

Limited (finite) replication occurs in certain cells in sugar solutions. So your claim is wrong.

Unlimited (infinite) replication is probably impossible anyway due to finiteness of matter and energy in the universe.

In both cases I don't get your point.

[Jouni]

Limited (finite) replication occurs in certain cells in sugar solutions. So your claim is wrong.

Unlimited (infinite) replication is probably impossible anyway due to finiteness of matter and energy in the universe.

In both cases I don't get your point.

Of course the cells replicate, because they're part of an extremely complex ecosystem. Remove the sugar solution and replace it with raw materials in forms that could feasibly exist without any kind of ecosystem. Do the cells still replicate?

[ZetaX]

Of course the cells replicate, because they're part of an extremely complex ecosystem. Remove the sugar solution and replace it with raw materials in forms that could feasibly exist without any kind of ecosystem. Do the cells still replicate?

Why should it apply, but not the following one?

"Remove the matter and energy and replace it with pure vacuum. Do the probes [or anything else] still replicate?"

It's simply a matter of what you consider as given. We know that some alcohols can form without life, and there are life forms living of alcohol; so there you have another example, this time even following your meaning of "no ecosystem" (again: what does that mean in this context¿).

[Jouni]

Why should it apply, but not the following one?

"Remove the matter and energy and replace it with pure vacuum. Do the probes [or anything else] still replicate?"

It's simply a matter of what you consider as given. We know that some alcohols can form without life, and there are life forms living of alcohol; so there you have another example, this time even following your meaning of "no ecosystem" (again: what does that mean in this context¿).

This is essentially a complexity question. If we take a system, and place it in an environment not significantly affected by another system of similar or greater complexity, can it replicate itself? If yes, then it should be possible to launch von Neumann probes and expect them to replicate themselves, given enough energy and raw materials. Otherwise replication should be possible only with the help of a sufficiently advanced civilization.

In more abstract terms, the question is about whether a system can replicate by itself or only with the help of a more complex system. Put in this way, it feels similar to many questions in mathematical logic, computability theory, and complexity theory.

[spudman2]

Oh, I have a NASA-authored article on this subject! Gimme a minute... *digs through folders*

Here ya go! Wait... I think I have a second available too... *digs through folders*

Eeeh... I have a .pdf, but I can't find a place that's hosting it freely that I can link into here.

Edited August 1, 2015 by spudman2

[Thomassino]

I'd like to bring one smart man named Fermi into this discussion. So, if is so easy to colonize space via these probes, where are they? Given the age of the Universe, there should be hundreds or even thousands of these probes already on Earth.

[magnemoe]

Well...

Yes one set of cancer cells was able to survive over time in an substrate, or rather an mutation of the cancer cells was able to survive in that environment.

Do not see how this changes anything, they are unable to survive in the wild and even so they would get eaten by other stuff.

As for humans you would need an group, not only for reproduction but also to run an colony.

- - - Updated - - -

I kind of believe that von Neumann machines are impossible. Not only physically impossible, but also logically impossible. I guess they're one of those science fiction ideas that sound too easy to be true.

All evidence so far suggests that (self-) replication is only possible in a system much more complex than the replicated object. In other words, if you want to create a complex machine, you must start with an even more complex machine. Or wait until evolution manages to create an ecosystem complex enough to create the machine.

Why life works, its not impossible to imagine an automated mining facility connected to an advanced factory able to create an copy of itself and all the other equipment and finally build an starship.

Problem is that with current technology it could not be scaled down enough so you would end up with something the size of an small town as seed, and AI is not good enough for doing this including repairs, you would not need sapient level AI.

However the starship and miniaturization is the hard part.

[Jouni]

Why life works, its not impossible to imagine an automated mining facility connected to an advanced factory able to create an copy of itself and all the other equipment and finally build an starship.

Biology is the main reason why I don't believe that self-replicating machines could work. Organisms do reproduce, but only with the support of an entire ecosystem. The more complex an organism is, the more support it requires for reproduction, and the more likely it becomes that it can't continue reproducing after changes to the ecosystem.