English: This image illustrates the exchange of information with an object falling into a black hole. An observer, O, sends timestamped radar pulses to a reflective infalling object P, as the object approaches the black hole's event horizon H. When P is far from the hole, the radar pulse is returned in the expected amount of time (pulse 1). When the object is close to the horizon, the return pulse is delayed by an arbitrarily large amount of time (pulse 2). Pulses emitted after pulse 2 are not returned (pulse 3), even though an image of the object is observed at the time the pulse is emitted (when pulse 3 is emitted, the observer has seen pulse 1 returned and is waiting for the return of pulse 2). --Christopher Thomas 19:21, 29 December 2005 (UTC) I, the author of this image, hereby release it for use under the Creative Commons "Share Alike" license. --Christopher Thomas 19:15, 29 December 2005 (UTC)