u/Elden_Lady

Hello! Could someone explain what the particle horizon is like I’m 5?

I know it’s defined as the boundary of the observable universe, and it’s the distance at which light emitted at the time of the Big Bang would reach us - but I thought there was a period right after the big bang where we cannot see? Where light could not travel to us?

If the latter is true, how do we know that light coming from the particle horizon was emitted at the time of the big bang?

Thank you in advance! ☺️