The Schwarzschild radius is the size an object's mass would need to be compressed into for its escape velocity to equal the speed of light — the boundary of a black hole's event horizon, beyond which nothing, not even light, can escape..
The Schwarzschild radius is the size an object's mass would need to be compressed into for its escape velocity to equal the speed of light — the boundary of a black hole's event horizon, beyond which nothing, not even light, can escape.
For the Sun (M = 1.989×10³⁰ kg): Rs = (2 × 6.674×10⁻¹¹ × 1.989×10³⁰) / (299792458)² ≈ 2,954 m (about 2.95 km) — if the Sun were ever compressed to this size, it would become a black hole.
The radius to which mass would need to be compressed to become a black hole.
Schwarzschild radius = 2GM ÷ c².
About 9 millimeters, illustrating how extreme this threshold is.