Dark matter is called “dark” precisely because it does not interact with regular matter and other particles through the electromagnetic force, which is responsible for interactions between charged particles. Dark matter does not emit, absorb, or reflect light or other forms of electromagnetic radiation, which is why it cannot be directly observed.

However, dark matter is inferred to interact gravitationally with regular matter and other particles. The gravitational force is a universal force that affects all objects with mass, including dark matter. Dark matter’s gravitational interactions are responsible for its observable effects on visible matter and the dynamics of galaxies and galaxy clusters.

One of the key pieces of evidence for dark matter’s existence is its gravitational effects on the motion of stars and gas in galaxies. Dark matter’s presence is inferred from the way it influences the rotation curves of galaxies, causing stars and gas in the outer regions to move faster than expected based on the visible matter alone.

Moreover, dark matter plays a crucial role in the large-scale structure of the universe. Its gravitational pull provides the scaffolding for the formation of galaxies, galaxy clusters, and other cosmic structures.

Despite its gravitational interactions, dark matter’s other properties and specific interactions with other particles remain largely unknown. Scientists are actively searching for evidence of more direct interactions, such as the hypothetical weakly interacting massive particles (WIMPs) or other dark matter candidates. These particles, if they exist, would have extremely weak interactions with regular matter and would require highly sensitive detectors or particle colliders to be detected.

Understanding the nature of dark matter and its interactions with regular matter is an ongoing area of research in particle physics, astrophysics, and cosmology. Discovering the true identity of dark matter particles and their properties would provide crucial insights into the fundamental nature of the universe.