Feasibility of Molecular Disassemblers

Question

When I come across weapons associated with Nanotechnology, the first that often shows up are Molecular Disassemblers, or what others would like to call Grey Goo.

Molecular Disassemblers utilise particles that can break down any material at a molecular level. Many have often confirmed that nanotechnology can allow for its existence.

However, I have never seen actual proof of its existence, though there is no proof of it being impossible either. What is more, small-scale molecular assemblers have been already created.

Thus I have to ask, if such particles, both biological and mechanical, and allow such a weapon to exist.

Answer 1

We know that such a thing in the broadest sense is possible, because we can have a look at the bacteria and fungi in the real world, and see that they can break down a wide variety of materials.

Note that arbitrary materials are not broken down by evolved disassemblers, because some things can't usefully provide any energy to the disassembler. Artificial disassemblers will run into the same problem, because there's limited scope for power storage or supply in something the size of a bacterium (or even smaller) and breaking up particularly strong molecular bonds is going to need a lot of oomph.

Furthermore, they often require specialist environments in order to operate... ready access to oxygen, for example, or water. Man-made mechanochemical disassemblers might need to operate in a vacuum.

Whether Drexler-style self-replicating omni-capable nanoswarms are at all plausible, let alone possible is still an open question (the outlook isn't great, to be honest) but they are unlikely of being able to do the grey goo trick on an arbitrary selection of targets.

Answer 2

Thus I have to ask, if such particles, both biological and mechanical, and allow such a weapon to exist.

Yes. There's nothing violating the laws of physics or our understanding in chemistry for their to be a conceivable methods of a universal molecular disassembler.

However, I have never seen actual proof of its existence, though there is no proof of it being impossible either. What is more, small-scale molecular assemblers have been already created.

Yes, there's a reason for this - because it would requires absurd amounts of energy to have something be able to universally do it, and something with requires immense amounts of specialized tools if you want to be able to handle every molecular bond.

The 'self-replicating nanoswarm' possibility of Gray Goo scenario is possible, but in the sense of 'doesn't violate the laws of physics' and not in the sense of 'likely to happen in the next century'.

Answer 3

Enzymes and Carbon Chain Cracking

There is already an example of molecular disassemblers in your mouth, it's called Amylase. This is an enzyme which can restructure starch compounds and break them down into smaller glucose structures. To do this, it promotes hydrolysis of several carbon bonds in the molecules' structures. In effect, it disassembles complex organic molecules into simpler "building blocks" (sugars).

As all organic matter on this place is entirely constructed out of complex carbon long-chain structures, an enhanced Enzyme that could disassemble any organic structure into glucose building blocks would be a terrifying thing indeed.