English: This image illustrates the forward light cones of points along the worldlines of objects moving near a black hole. In case 1), the light cones are not substantially affected by the hole's gravity. In case 2), the light cones are tilted towards the black hole, but emitted light can still escape. In case 3), as the infalling object approaches the event horizon, the forward light cone of the object tilts so that its outer edge is aligned with the horizon. Light emitted at this event takes an arbitrarily long time to escape the hole. In case 4), the infalling object is within the event horizon, and all parts of the light cone point intwards. Moving towards the singularity is inevitable. --Christopher Thomas 19:09, 29 December 2005 (UTC) I, the author of this image, hereby release it for use under the Creative Commons "Share Alike" license. --Christopher Thomas 19:05, 29 December 2005 (UTC)