Dark matter

Dark matter is a form of matter once thought to account for approximately 85% of the matter in the universe. It is called dark because it does not appear to interact with the electromagnetic field, which means it doesn't absorb, reflect or emit electromagnetic radiation.

Type 1 civilizations find it to comprise of particles not hitherto detected in previous standard and therefore limited models of particle physics. Once discovered, the term "dark matter" was regarded in the same way as aether which was once thought to comprise most of the observable universe beyond earth.

See also:

Dark energy