Traditionally, mass distributions in galaxies were believed to follow a decline with radius,
according to Keplerian dynamics. However, observations have consistently demonstrated
that the rotational velocities of stars in the outer regions of spiral galaxies remain nearly
flat, contradicting expectations based solely on visible matter Rubin1980, Zwicky1937.
This observation gives rise to the necessity of dark matter, which is theorized to make up
approximately 85% of the universe’s total mass Bertone2010.
Analyzing the Rotational Curves of Spiral Galaxies: Implications for Dark Matter and Galactic Dynamics
Spiral galaxies are among the most visually stunning and dynamic structures in the uni-
verse. They represent roughly 60% of all galaxies observed in the local universe and are
fundamental to the study of cosmic evolution.