Timeline of black hole physics

The following timeline outlines notable discoveries in the study of black holes in physics, beginning in the 18th century and continuing to modern observations. == Pre-20th century == 1640 — Ismaël Bullialdus suggests an inverse-square gravitational force law 1676 — Ole Rømer demonstrates that light has a finite speed 1684 — Isaac Newton writes down his inverse-square law of universal gravitation 1758 — Rudjer Josip Boscovich develops his theory of forces, where gravity can be repulsive on small distances.

Source: Wikipedia — Timeline of black hole physics (CC BY-SA 4.0)