[Popular Mechanics] Scientists believe there could be an "anti-universe" somewhere out there that looks like the mirror image of our own universe, reciprocating almost everything we do. If this theory holds true, it could explain the presence of dark matter.First, some background: the "Big Bang" is a collective term that includes a variety of theories studied by cosmologists, the scientists who try to rewind the clock as close to the very beginning of the universe as possible. Most agree that matter exploded forth, but there are different opinions on, for example, whether the temperature was extremely hot or absolute-zero cold at that initial moment.
There are also disagreements about what may have happened prior to the bang itself. Could it be that what we call the Big Bang was the inflection point of an even bigger bounce in progress? Think of the point when you bounce on the trampoline and your feet almost touch the ground beneath—then imagine only seeing the subsequent bounce upward; it’s meaningless without the first, downward half of the bounce!