Galactic — Dynamics

: Visible matter cannot explain observed orbital speeds. A massive, invisible dark matter halo is required to keep galaxies from flying apart. Key Dynamical Components 1. The Galactic Disk

: Many galaxies, including our own, have a central bar that funnels gas toward the center, feeding the central black hole. 2. The Galactic Halo & Bulge Galactic Dynamics

: These are not permanent "arms" but density waves where stars and gas momentarily slow down, triggering star formation. : Visible matter cannot explain observed orbital speeds

: Unlike gas particles, stars rarely "hit" each other. Their motion is dictated by the smoothed-out gravitational potential of the entire galaxy rather than individual encounters. including our own