This article is about the astronomical "horizon problem". For the problem relating to artificial intelligence, see Horizon effect.
The horizon problem (also known as the homogeneity problem) is a cosmologicalfine-tuning problem within the Big Bang model of the universe. It arises due to the difficulty in explaining the observed homogeneity of causally disconnected regions of space in the absence of a mechanism that sets the same initial conditions everywhere. It was first pointed out by Wolfgang Rindler in 1956.[1]