Black hole physics
type: Concept
narrower: Kruskal diagram

Kruskal diagram
type: Concept
contributor: AAS Frey.Katie
modified: 2020-11-10T18:10:20.916Z
modified: 2020-11-10T18:10:10.646Z
alternative label: Kruskal-Szekeres diagram
broader: Black hole physics
definition: A diagram used to plot trajectories in space-time near a black hole. The vertical and horizontal axes are two complicated functions of time and distance from the black hole. Lines of constant time radiate from the origin of the diagram, with steeper slopes corresponding to later times. Lines of constant distance are hyperbolas, lines of constant time pass through the origin; photons always travel along diagonal lines at ±45° to the vertical. The trajectory of an object falling into the black hole is shown as a curving line moving upward on the diagram at less than 45° to the vertical.