Theories were not necessarily always correct. What people considered correct was merely what could explain observed phenomena; when those phenomena could be explained without them, the theories likely contained errors.
Occam's Razor Principle stated: do not multiply entities without necessity. It made sense when applied to physical theories as well.
Based on their observations at the time, humanity estimated that Dark Matter accounted for 25% of the universe's mass, Dark Energy accounted for 70% of its total mass, and only the remaining 5% was visible matter—the dazzling stars scattered across the sky.
But as technology advanced, Dark Energy, once regarded by humanity as equivalent to mass and included in calculations of the universe's total mass, seemed not to account for nearly as much as previously believed.
The root of this lay in the fact that as technology advanced, Human Civilization detected more and more unknowns. The "dark" in Dark Energy essentially meant unknown or invisible. In other words, Dark Energy was something that could neither be seen nor touched, existing only in theory.
The same was true of Dark Matter.
As technology advanced, many things that had originally been classified as Dark Matter acquired names of their own. Tachyons, for instance, had once been considered a form of hot Dark Matter by humanity. But after reaching the level of a Level Six Civilization, humanity discovered that view to be mistaken.
Tachyons did not belong within the Dark Matter system.
Dark Energy, meanwhile, was even more mysterious. After discovering certain reaction patterns of Dark Matter, humanity realized that this universe seemed not to require so much Dark Energy.
Bright Matter accounted for more than 5% of the universe's total mass, while Dark Energy accounted for less than 70%. Only the calculations for Dark Matter still came close to 25%. New theories