Dark matter is a mysterious and invisible substance that is thought to make up the majority of the universe's matter, exceeding 90%. Its existence was proposed in the 1930s by the astronomer Fritz Zwicky, who studied the motion of galaxies and found that the visible matter alone could not account for their dynamics. This led to the hypothesis of dark matter, which remains a central topic in astrophysics and cosmology.

Despite being undetectable by conventional means, dark matter influences the universe's structure and behavior through its gravitational effects. Understanding this enigmatic material is crucial for grasping the overall composition of the cosmos, showing how much more there is to discover beyond what is visible. The significance of dark matter is highlighted in works like Bill Bryson's "A Short History of Nearly Everything," which explores foundational concepts about our universe.