Primordium Sigma

Σ particles, or Primordium Sigma, has a special type of property that make them a perfect barrier for anything when on it's own (when connected with other particles it's properties change). Any force felt upon pure Primordial Sigma will be equally felt onto the object that caused the force.

Due to this property, many high level civilizations have employed 'Primordium Sigma' Barriers all along their universe, making invasions from other high level civilization enemies a whole lot safer, and will require the enemies to lose alot of their attackers to get in.