Science fiction writers love to play with parallel universes, but recently the idea
of a mulitverse has held the attention of famous scientists. As string theory has
evolved since 1984, space has an infinity of universes, some of them are nearer than
a millimeter away, and each possesses its own black, white, and multicolor holes.
There is matter colder and darker than we can detect. In some cases, time is reversed,
and you can truly go back to the future.
You may need to completely rearrange your mind to understand this. You have
to get accustomed to the idea that the third dimension is only the beginning.
In other words, there is a universe in which your mother was born after you,
but you both still exist. In another universe, King Arthur's Round Table replaces
the UN. Maybe only the last quark is different, maybe nothing is the same. There are
more possibilities than you can name, or even imagine.