Penrose diagram

A Penrose diagram is a diagram (named for Roger Penrose) that shows the global causal structure of a spacetime. It is a spacetime diagram in which all light rays are shown as traveling at 45° and in which, therefore, all particles with mass are shown as traveling on trajectories that lie within the light cone which sits at every point in the diagram. A Penrose diagram allows even infinite spacetime to be represent finitely by means of an appropriate change of coordinates.


Penrose diagram of the universe
Penrose diagram of the universe