A block when it collides with another block, interlocks with it to form a composite block, …

A Block if it collides with a composite block.. it interlocks with it to form a bigger composite block…. So in this way a composite block grows in size by attracting simple blocks to collide with it..

But at a certain condition the composite block may not have any free jutting points to interlock with the incoming simple block.. at this state it splits into two parts, so that the incoming simple block can interlock with either of the split pieces….

So here the overriding conditions are:

1. if two blocks (both either simple or composite) collide then they must either interlock or the composite block must split into two..

2. when two simple blocks collide they always interlock…

So here we have a simple block which interlocks with other simple blocks to form a composite block, and further grows in size by interlocking with more simple blocks.. and when it cannot interlock with anymore simple blocks.. it spilts into two parts.. and each of these two parts start to grow in size by interlocking until they cannot interlock anymore.. then they too split…and so on..

I think this is an example for an self replicating machine… what say?

Though I agree with Kadamose's point, any sufficiently advanced nano-factory would be self replicating if fed its own design. Even if centralized would only be a matter of time before the thing gets down to a reasonble price and the plans are leaked or reverse engineered openly.

First, I will respond to your comments:

Second, you control the products of any nanoscale manufacturing system by deciding what blueprints to feed it. Even if a "self-replicator" included blueprints for its own construction (a waste of memory), to make any useful product you'd have to give it the blueprints for that product.

It doesn't have to be this complex – in fact, one could write a program that's over a terabyte in size, that catalogs, stores, and details how to construct the materials in question. This program would be either installed in the core of the nanomachines, themselves, or would be installed on a node, which the nanomachines will communicate with. (Completed works will be installed via the core, while products in alpha and beta stages will be accessed via the node) – while what you say about the blueprints is true…it will only be true for the pioneers of this technology, and the inevitable result will be the self-automation of the nanomachines.

In the not-so-distant future, you will be able to communicate with these nanomachines by thought alone…and no blueprints will be required, because they will already be programmed in, thanks to the pioneers (i.e. 'us').

"Third–and read this twice, because it's important–breaking down arbitrary molecular structures will be very difficult and inefficient to do via mechanical "disassemblers." The only reason disassemblers were ever proposed was for slow, painstaking research–not recycling. A "self-replicator" would not be built for recycling, but for using simple feedstock molecules"

If a nanomachine can follow a blueprint, step by step – why can't it follow those steps in reverse? If the nanomachines are 'aware' of the basic elements, and knows how to manipulate them to assemble a given product, why is it not possible to take that same product and disassemble it? I do not see how it would be more technically difficult than the assembly process.

Fourth, it's true that nanofactories were chronologically invented after gray goo was discussed. But it's also true that they are simply more efficient architectures than small non-redundant manufacturing systems. Fact is, most approaches to small non-redundant ("self-replicating") manufacturing systems would be also incapable of mutating to eat the planet. It's just more obvious that the nanofactory architecture is safe.

Better safe than sorry, you say. Tell me, has anyone truly advanced in life without taking drastic risks? The nanofactory idea is nothing more than a plan to keep the technology out of the hands of the masses…granted, they'll receive and consume products made by these factories, but they won't have anything to do with the creation process…which is what nanotechnology is all about.

Self-Replication = Abundance = Freedom
Nanofactory = Scarcity = Slavery

It's beginning to sound like Foresight and everyone in it, support a fascist vision of nanotech. It didn't always use to be like this either…I wonder what happened?

There's been some rather confused comment above, asserting that self-replicators are inherently better than nanofactories because they can't be centrally controlled and they can recycle anything.

First, the idea of "self-replicator" as used in the comments isn't well defined, and I won't try to invent a meaning that's consistent with all the ways it's used above.

Second, you control the products of any nanoscale manufacturing system by deciding what blueprints to feed it. Even if a "self-replicator" included blueprints for its own construction (a waste of memory), to make any useful product you'd have to give it the blueprints for that product.

Third–and read this twice, because it's important–breaking down arbitrary molecular structures will be very difficult and inefficient to do via mechanical "disassemblers." The only reason disassemblers were ever proposed was for slow, painstaking research–not recycling. A "self-replicator" would not be built for recycling, but for using simple feedstock molecules.

Fourth, it's true that nanofactories were chronologically invented after gray goo was discussed. But it's also true that they are simply more efficient architectures than small non-redundant manufacturing systems. Fact is, most approaches to small non-redundant ("self-replicating") manufacturing systems would be also incapable of mutating to eat the planet. It's just more obvious that the nanofactory architecture is safe.

Chris

You seem to forget, my friend, that space will become a non-issue. Especially in a nanotech world advanced enough to allow you to create some sort of "Nano Sterilization Bug". It would assume true molecular assemby, and self replication. The same requirements as say…. utility fog? Surround yourself w/ the utility fog, and what do you have? A holodek! And what is in this holodek? Limitless space indistiguishable from reality to do with what you wish, and molecular manufactories to keep you fed, and taken care of. All it needs is electricity, and you could run it on solar, floating in space. bam… no more pesky people to deal with. Oh, and by the way, IANA Psychiatrist, but you seem to be displaying that "Its mine, not yours" mentality in full force. Only you are not doing it with money, or things, but with the future of humanity. What you are suggesting seems quite close to an "Ethnic Cleansing"

Y

There should be no limitations put on the assembler, since that will just give people ideas to crack it. Limitations only inspire people to reach beyond those boundries.

You have to keep in mind that with the coming age of true nanotechnology, things such as money and religion aren't going to exist anymore; thus getting rid of crimes such as murder (murder that's based on materialism or beliefs – which happens to be 95% of the reasons why people are murdered in the first place)

Of course, there will always be people, like me, who will forever hold a grudge against mankind due to its "It's mine; not yours" mentality – which has, unsurprisingly, held us all back from achieving anything significant up to this point. If this mentality did not exist, mankind would have reached out to the stars and nanotechnology would have been created thousands of years ago (of course, who is to say we didn't already -our 'history' is all a fabrication anyway.)

I will not lie to you – one of the main reasons I am looking forward to nanotech so much is so that I can:

Plan A: Shut down the human reproductive system.
Plan B: Destroy 3/4s of the worlds population.

Please keep in mind that Plan B is a last resort only if Plan A were to fail. I know it sounds crazy, but these are necessary evils. There MUST be limits to growth, and simply exporting everyone into space isn't going to solve the problem, because, they too, will reproduce and infest the universe with their vile consumer tendencies.

Our destiny, as a species, is to become gods. Those who can't accept that destiny, don't deserve to exist in the first place.

Conde? Rumsfeld? That you?

From this point I'd like to raise a question.

I'm completely for the advancement of nano-scale manufacturing and love the idea of everyone having some kind of access to their own private assembler, but how on Earth can this be deemed safe?

We would be giving the ability for any one person to assemble whatever they can possibly dream of. A respectable person would probably manufacture his food, home electronics, jewelry, and such, but what of the criminally insane person who wants to manufacture weapons capable of mass destruction? Even by shipping assemblers with firmware which forbids or restricts things assembled, this could always be reverse engineered. Scenarios like this are probably nanotechnology's greatest adversary.

How do you, or really anyone reading this now, propose this is resolved?