Yay, humans are re-inventing proteins!
Self-Assembly Shows Promise for Extending Moore’s Law
11–20 of 23 posts
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#12Earlier quoted context omitted.
What were the plot holes with it?
Fundamentally, we already have self-replicating robots with nano-level structures that consume materials from their surroundings and build new copies. They're called bacteria. The interesting bit over here is not the observation, but the question why we aren't all covered in bacterial goo miles thick like run-away nano-technology. (we do have them all around us and in us for what its worth) I think a part of the answ…
Bacteria aren't capable of spontaneously organizing into multi-celled organisms when they reach critical mass.
Fungi behave much more like this. The thing we don't have an example of in nature is an intelligent creature capable of making tools that can reproduce itself from a single cell. It's definitely a hard engineering problem, but it's conceivable. It's also conceivable that such an entity could seek out and remove any malfunctioning sub-entities.
We humans actually behave a lot like that, it's just that you need at least a whole human to grow another human. It's not so strange to imagine a designed, intelligent creature that can regrow itself from a small piece.
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#13Earlier quoted context omitted.
What were the plot holes with it?
Fundamentally, we already have self-replicating robots with nano-level structures that consume materials from their surroundings and build new copies. They're called bacteria. The interesting bit over here is not the observation, but the question why we aren't all covered in bacterial goo miles thick like run-away nano-technology. (we do have them all around us and in us for what its worth) I think a part of the answ…
Your analysis ignores the key point that bacteria operate on simple rules based entirely on local concerns, which is not the proposed case in the sci-fi story.
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#14Earlier quoted context omitted.
What were the plot holes with it?
Fundamentally, we already have self-replicating robots with nano-level structures that consume materials from their surroundings and build new copies. They're called bacteria. The interesting bit over here is not the observation, but the question why we aren't all covered in bacterial goo miles thick like run-away nano-technology. (we do have them all around us and in us for what its worth) I think a part of the answ…
Evolution isn't likely to happen in self-replicating robots. Evolution needs a continuous fitness landscape like DNA. A random bitflip is more likely to produce a fatal error than do something beneficial. Even worse if the code is encrypted before copying. There also aren't that many generations. At exponential growth, it only takes a few dozen generations to reach the maximum population limit and stop replicating. Not enough generations for evolution to happen.
Obviously the technical issues with self-replication are difficult, but nature was able to do it with relatively crude methods. No doubt we could eventually design something significantly better. One major advantage would be mass cooperation. Evolution has no incentive for individuals to cooperate with each other, but designed nanobots can specialize and benefit from economies of scale.
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#15Earlier quoted context omitted.
Fundamentally, we already have self-replicating robots with nano-level structures that consume materials from their surroundings and build new copies. They're called bacteria. The interesting bit over here is not the observation, but the question why we aren't all covered in bacterial goo miles thick like run-away nano-technology. (we do have them all around us and in us for what its worth) I think a part of the answ…
Evolution isn't likely to happen in self-replicating robots. Evolution needs a continuous fitness landscape like DNA. A random bitflip is more likely to produce a fatal error than do something beneficial. Even worse if the code is encrypted before copying. There also aren't that many generations. At exponential growth, it only takes a few dozen generations to reach the maximum population limit and stop replicating. N…
That last sentence is rather odd, coming from a gigantic lump of some trillions of cooperating cells.
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#16What exactly is the holdup with extreme ultraviolet sources? I remember reading an article that said synchrotrons could generate x-ray beams with the power density of a blowtorch, and some others suggesting free-electron lasers should be able to generate anything down to hard x-rays with more or less arbitrarily high power density; why don't these suffice?
The reliable sources for high-power EUV light (synchotrons and free-electron lasers) are all expensive and gigantic (building sized) due to the accelerator and shielding required for the electron beam. They're completely impractical for industrial scale manufacture (you fundamentally couldn't put 100 of them into a single factory).
Heating tin in a regular laser until it forms plasma and starts emitting 13.5 nm light is much simpler to scale down (since it doesn't involve an accelerated electron beam) but you lose large amounts of power while trying to form a partially coherent beam out of the result, turning hundreds of kilowatts of infra-red laser power into mere 10's of watts of EUV power.
The high input to output ratio means that you need to be really careful that the large amount of dissipated power doesn't cause problems. Tiny misalignment problems often result in the 200kW infra-red input laser melting the entire device into a puddle of former components.
http://www.eetimes.com/document.asp?doc_id=1321162&page_numb...
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#17Earlier quoted context omitted.
What were the plot holes with it?
Fundamentally, we already have self-replicating robots with nano-level structures that consume materials from their surroundings and build new copies. They're called bacteria. The interesting bit over here is not the observation, but the question why we aren't all covered in bacterial goo miles thick like run-away nano-technology. (we do have them all around us and in us for what its worth) I think a part of the answ…
Viral capsids are an even simpler example of self-assembly. In many types of virus, the individual subunits spontaneously piece together to form the capsid in an entirely passive process driven only by Brownian motion, and defined by the chemical composition of the subunits and the solution they are contained in.
A decent illustration of this concept: https://www.youtube.com/watch?v=X-8MP7g8XOE
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#18Lithography guiding finer block copolymers pleasingly follows Feynman's pantograph talk
http://www.zyvex.com/nanotech/feynman.html
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#19Earlier quoted context omitted.
Fundamentally, we already have self-replicating robots with nano-level structures that consume materials from their surroundings and build new copies. They're called bacteria. The interesting bit over here is not the observation, but the question why we aren't all covered in bacterial goo miles thick like run-away nano-technology. (we do have them all around us and in us for what its worth) I think a part of the answ…
Bacteria aren't capable of spontaneously organizing into multi-celled organisms when they reach critical mass. Fungi behave much more like this. The thing we don't have an example of in nature is an intelligent creature capable of making tools that can reproduce itself from a single cell. It's definitely a hard engineering problem, but it's conceivable. It's also conceivable that such an entity could seek out and rem…
[deleted]
Re: Self-Assembly Shows Promise for Extending Moore’s Law
#20What exactly is the holdup with extreme ultraviolet sources? I remember reading an article that said synchrotrons could generate x-ray beams with the power density of a blowtorch, and some others suggesting free-electron lasers should be able to generate anything down to hard x-rays with more or less arbitrarily high power density; why don't these suffice?
They're very expensive. (Which is also the problem with current tin plasma sources. They work, but they just aren't cost effective.)
There are interesting ideas to downsize synchrotrons though, and if we can both make synchrotrons smaller and semiconductor factories bigger, then perhaps synchrotron sources could make sense. But even then, I worry that if a $20 billion semiconductor plant has only one $1 billion synchrotron source, there is a tremendous amount of risk concentrated in that single source. If the source goes down, the rest of the $20 billion plant goes idle.