Collapsium

Collapsium (sometimes also known as monopolium) is exotic matter manufactured by using magnetic monopoles to collapse ordinary matter down to an ultra-dense state.

Manufacture

Creation of collapsium requires a sizeable quantity of monopoles, and a suitable starter object. This is typically a metallic asteroid, or a sphere of dense metals refined from one. The monopoles are injected into the object, and induced to bond with its atoms, displacing their electrons. This reduces their size drastically, and the object begins to shrink, increasing in density. As it does so, self-gravitation takes over and further assists the object's collapse, until it is reduced to a small sphere of ultradense, degenerate matter, similar to that of a neutron star. A kilometer-size asteroid will reduce down to a collapsium sphere a few mere meters across.

Uses

Compensator Masses

Collapsium spheres, due to their incredible density, can have an equally drastic gravitational field in close proximity. Some groups have attempted to use this to counteract the extreme tides of celestial objects like black holes and neutron stars, enabling research at low altitudes that would otherwise tear any material ship apart. This is done by arranging the collapsium "compensator masses" such that their gravity precisely cancels out the gravity of the other object in the region the spacecraft will be. This has proven difficult to implement in practice, as the huge weight of collapsium compensator masses makes them extremely difficult to move with rocket engines. They will usually be produced on-site from asteroids already orbiting the target object. Ancient collapsium spheres, presumably left from paleocivilization science expeditions, have been found around several black holes and neutron stars in Starweb space.

Habitats

Some polities and cultures have experimented with using collapsium spheres as "cores" for miniature worlds which, despite being little bigger than an asteroid, nontheless have non-trivial surface gravity.

Projectiles

Several militaries have experimented with microsopic collapsium bullets, small enough to be carried aboard a ship and fired from a linear accelerator, but whose tremendous density enables them to breach any ordinary armor.

Armor

Collapsium projectiles drove equivalent research into collapsium armor. This must be very thin to fit over a ship with reasonable mass, though some polities have built orbital forts protected with thicker collapsium walls. This, of course, renders them virtually immobile.

Wormhole Ballast

A common use for collapsium in the modern period is as ballast mass for stargates. The usual process of stargate construction already involves landing a wormhole on an asteroid as a source for mass to exchange for parts and equipment, modern practice now often involves compression a portion of this rock down to collapsium which is placed into the wormhole throat to give it an initial buffer without taking up much internal space.