# Event Horizon

Could someone give me a formula that would describe an event horizon, and also explain your view?

$$v_{esc}=\sqrt{\frac{2GM}{r}}$$
$$v_{esc}^2=\frac{2GM}{r}$$
$$r=\frac{2GM}{v_{esc}^2}$$
$$r=\frac{2GM}{c^2}$$