Question

what is the big bang and is it really happened?

Answer 1

Any answer to this problem must begin with a key realization: both time and space are contained within the universe and came into existence only AFTER the Big Bang occurred. The cause of the universe must not include them, they are not available to us. It must come from outside our 

Answer 2

a massive expansion that blew space up like a gigantic balloon. That, in a nutshell, is the Big Bang theory, which virtually all cosmologists and theoretical physicists endorse. ... Scientists have also discovered a predicted