Momentism

Momentism (commonly known as mass or weight) was a property exhibited by particles that interacted with the momenton field. These most importantly included the particles of matter, but some force carriers also had mass. Ironically, momentons themselves had mass.

Momentism existed due to momentons, force carrier particles that flitted in and out of existence everywhere in the universe, forming an unbroken field known as the momenton field. Many types of particle interacted with the momenton field, causing exhibit properties of momentism, including inertia, momentum, inability to travel at lightspeed under normal conditions, and gravity (caused by gravitons, which were released when massive particles came into contact with momentons). Some particles (such as photons and gravitons) did not interact with the momenton field. Consequently, they had no mass and no gravity, and traveled at the speed of light.

Interference
The momenton field was spread evenly throughout the universe. However, using advanced technology, the momenton field could be disrupted. This was done in hyperdrives and warp drives to allow superluminal travel. Complete removal of the momenton field in an area caused matter to behave in incredibly strange ways, causing it to travel at lightspeed, but also causing composite particles such as atoms to break down.