What Is Dark Matter?

Despite its elusive nature, dark matter is a crucial component of the cosmos. Because it is electromagnetically neutral, dark matter does not interact with light and is thus impossible to see directly. Although it is invisible, we infer its existence from its gravitational effects on visible matter, such as stars and galaxies. For instance, galaxies rotate at speeds that would tear them apart if only the visible matter were holding them together. This suggests that an unseen mass, dark matter, is providing the necessary gravitational pull to keep them intact.

The gravitational influence of dark matter extends beyond individual galaxies. It plays a vital role in the formation and structure of galaxy clusters. Additionally, dark matter’s gravitational effects can bend space and thereby distort the passage of light from distant objects, a phenomenon known as gravitational lensing. Such distortion provides further evidence of dark matter’s presence and helps astronomers map its distribution in the universe.

Scientists have hypothesized that most dark matter consists of heavy, electromagnetically neutral subatomic particles known as WIMPs (Weakly Interacting Massive Particles). Despite extensive research, direct detection of dark matter remains elusive. Experiments at particle accelerators such as the Large Hadron Collider and laboratory detectors continue to search for these particles, hoping to uncover the true nature of dark matter.