Dimensional mine

A **dimensional mine** is a type of concealed weapon deployed by advanced civilizations into extrauniversal space or, under certain circumstances, within universes themselves, so as to limit transit through certain dimensional pathways and trap or destroy anything passing by.

The basic structure of a rudimentary dimensional mine is that of a rolled-up six-dimensional manifold comparable to those proposed by string theory. Inaccessible to lower-dimensional tampering due to being kept at extremely high energies, a manifold of this type has an external physical extent only measured in Planck lengths and is effectively completely undetectable to those less dimensionally capable. Civilizations then coat the inside of these manifolds with the most dangerous substrates they can produce, like grids of singularities, weaponized cosmological defects, or even large-scale portals linking to pocket universes whose laws of physics have been optimized for destruction (for example, lacking a strong nuclear force, or allowing for photon decay).

When triggered by any of a vast number of possible preset conditions, a dimensional mine unfurls and blossoms out into a much larger lower-dimensional form temporarily, before pulling anything within its area of influence inside it and recollapsing. Most dimensional mines self-reset, assuming their substrates are reusable or can at least be replenished, although some may need to be periodically cleaned out of debris from wrecked spacecraft, SAW gliders, dead entities, or whatever else ended up inside.

## Specialized mines

Certain types of dimensional mine, known as dimensional **dragmines**, use a gravitational field or comparable force of arbitrary strength to exert their influence when activated over as large an area as desired. Under certain circumstances, dragmines can be used to prevent extrauniversal transit altogether; when anchored to the membrane of a universe, some specialized models can redirect, "steal", and destroy anything trying to pass through.

Dimensional **infomines** use less-than-physical principles to stop the movement of information itself, preventing nudge drives from relaying infomatter, or even contaminating information about the mines themselves to protect their secrecy.

## Countermeasures and Demining

Detecting dimensional mines is easy for a civilization or entity with equivalent dimensional capabilities to the mines themselves; neutralizing them afterwards can be done through a variety of methods. One such method is to deploy small dimensional packets containing worker probes or similar devices onto the mines, so that they can manually release the manifold and spill its contents out such that they can be collected. Alternatively, piercing many types of dimensional mines with higher-dimensional defects can destroy them much more quickly.

Civilizations without the dimensional capacity to see and avoid mines are not entirely defenseless. One strategy that many have adopted has been to deploy probes and detect where the area of influence of each mine is by watching which probes get destroyed; under certain circumstances, probes can even relay information about the substrates in use and allow their civilizations to develop hardening techniques for their equipment or specialized counter-substrates to neutralize the mines from inside. This technique is less effective against infomines; civilizations encountering hazards that their equipment has difficulty remembering exists at all are frequently advised to contact local entities for more detailed cleanup.