[Timm]

Zitat von TomS

Am einfachsten Gullstrand–Painlevé bzw. raindrop coordinates

https://en.wikipedia.org/wiki/Gullst...peeds_of_light

At the event horizon, r=2M, the speed of light shining outward away from the center of black hole is dr/dt=0. It can not escape from the event horizon. Instead, it gets stuck at the event horizon. Since light moves faster than all others, matter can only move inward at the event horizon.

Danke, das war's, worauf ich hinauswollte.

Aus der Schwarzschildmetrik folgt hingegen dr/dt = +-(1 - 2m/r).