Question

what is the hotizon problem of the big bang theory? please explain.

Answer 1

The horizon problem ocuurs with big bang beacause it could not explain the homogeneity of causally disconnected regions of space in the absence of same initial conditions et all points.

COSMIC INFLATION is most commonly accepted solution of this problem.

When we observe light coming from a galaxy far from us lets it is 10 billion light ears away from an observer. Now if the observer sees another light coming from an other galaxy at 10 billion light years away but in oppossite direction of first, So the distance between to galaxies is 20 million years. But the Universe is only 13.8 billion years old according to Big Bang, This contradiction is known as horizon problem.