What term describes the unseen mass that influences galaxies yet does not emit light?

The term that describes the unseen mass influencing galaxies, which does not emit light, is dark matter. This form of matter makes up a significant portion of the universe's total mass and has been inferred from its gravitational effects on visible matter, such as stars and galaxies. While traditional matter emits or reflects light and can be observed directly, dark matter does not interact with electromagnetic forces, making it invisible to current observational tools.

Evidence for dark matter comes from various astronomical observations, such as the rotation curves of galaxies. These curves show that the outer regions of galaxies rotate at much higher speeds than expected based on the amount of visible matter present. This discrepancy suggests the presence of additional mass, leading to the conclusion that dark matter exists. Moreover, gravitational lensing, where the path of light from distant objects bends around massive clusters of galaxies, provides further support for dark matter's influence in the cosmos.

In contrast, antimatter is a form of matter composed of antiparticles, which are counterparts to the particles that make up normal matter, but do not account for the gravitational effects observed in galaxies. Visible matter refers to everything we can see and detect with telescopes, while circular matter is not a recognized term in astrophysics or cosmology. Therefore, dark matter is