Early Countermeasures
From Wise Nano
What countermeasures could be deployed before the development of molecular manufacturing, in order to defend against both accidents and at least the first generation of nanotech-based weapons? (See also Is there a superweapon?) Obviously some might appear prohibitively expensive or otherwise infeasible in the absence of the wide perception of a clear and imminent threat, but then a false alarm or close call could conceivably lead to almost anything being attempted.
First are listed what might be called "mechanisms of action". Eventually these should be followed by some particular devices and "actors"; and finally tactics and entire systems and networks of systems.
Mechanisms of Action
Air
While it is not normally be thought of as a "countermeasure", one of the more commonly suggested tactics for making sure molecular manufacturing systems don't produce "grey goo" is to make them require a vacuum or inert gas environment to operate within. To the extent that this can be accomplished, open air will then constitute one of the layers of defence.
Water
There are many properties of ordinary water that could potentially neutralize some devices, many of which may be listed separately below, but it is also worth considering the combination of them embodied in water:
- Viscosity
- Cohesivity
- Solvent action
- Oxygen deprivation
- High thermal conductivity
- High electrical conductivity (unless distilled)
- Cooling of hot objects (through boiling/evaporation)
- Expansion forces when frozen (unless distilled?)
- Rust/oxidation promotion
- Hardness/erosion (when flowing)
Solid Barriers
Walls, fences, suits, bags, boxes, nets, filters, rakes, etc. It's hard to imagine that such things won't have some role to play in defense, as they always have.
Mechanical Compression or Concussion
Whether with a mallet, a vice, or a high-speed projectile, no device can absorb an arbitrarily large compression or concussion force without sustaining damage. It's not fancy, but it is usually quite effective.
Blades, Lances, Saws, Drills, and Shears
Another trusty mechanical approach. Even if constructed from diamondoid threads, the principle is the same as with a sharpened stone blade.
Glue or Tar
The equivalent of fly-paper may not be very sophisticated, but might constitute a barrier to some forms of conceivable weaponry. And even if it's not much of a barrier, it might prove useful as part of a detection/monitoring system against at least some relatively primitive forms of tiny (and otherwise stealthy) devices.
Heat
Many things will melt, burn, or burst if heated. Even in lower quantities it may also produce other damaging mechanical stresses. It will often also alter the chemical reactivity of various materials and/or catalysts.
Cold
Cold makes many materials brittle, can cause some fluid-filled compartments to either burst or implode due to pressure changes, and can potentially create other damaging mechanical stresses. It will often also alter the chemical reactivity of various materials and/or catalysts. Extreme cold can also produce superconductivity in metals and certain other materials.
Acid, Soda, or Alcohol (Ph)
Self-evident.
Glycerine/Soap
Soapy water will quickly suffocate any insect, as well as most flames. It will also make many surfaces quite slippery, and will tend to heavily weigh down any fine mesh or grating.
Oils (low cohesivity liquids)
Oils can penetrate many cavities and materials which are impervious to water.
Salt or Saline
The primary distinctive characteristics of salt and saline is their ability to dehydrate and their effect on water ice. However they can also have a strong corrosive effect, particularly on metals, and other chemical and electrical effects when brought into contact with other materials.
Electrical Current
Various devices might be fried by applying or inducing an electrical current. Frequency (if AC, otherwise the fact that it's DC), voltage, and amperage may all be critical factors.
EM Radiation
UV, Infra-Red, microwaves, x-rays, and gamma rays are the most typically destructive wavelengths of EM radiation, but virtually any wavelength could potentially neutralize or at least impair some variety of device. In addition to potentially producing physical or chemical disruption or destruction, the potential for interference with electrical function or communication should also be considered.
EMP (Electro-Magentic Pulse)
Listed separately from EM Radiation, because the nature of the hazard is not the wavelength or intensity of the radiation by itself but the electro-magnetic effects of a large, sharp pulse of EM on electrically conducting objects.
Strong Magnetic Fields
One use of magnetic fields would be to gather or direct metallic objects for containment and eventual neutralization. Magnetic fields might also produce desctructive mechanical stresses in some objects/devices. Magnetic fields can also interfere with electrical operation of unshielded devices, especially if the magnetic fields are made to fluctuate. Test
Sound (particularly ultra-sound)
At least down to a certain scale, sound at resonant frequencies of undampened rigid bodies can have devestating effects when of sufficient amplitude. Whether this will be a common exploitable vulnerability in many micro- or nano-scopic devices remains to be seen. Load sounds can also rip or deform membranes and/or cables, beams, or threads at a wide range of frequencies. Sound may also be used to move or channel particles within a gas or liquid or loosely placed on a smooth, non-dampening surface.
Particle Beams
Can be composed of electrons, neutrons, ions, or more exotic particles.
Anti-matter
If all else fails, anti-matter will vaporize any ordinary matter it comes into contact with (and release massive doses of heat and light in the process). The primary difficulty, of course, is the vast expense of synthesizing anti-matter using current techniques.
