Cats that are neither alive nor dead, flipped coins that are neither heads nor tails until the hand that covers them is removed...there is something about such indeterminate states that many found very strange and hard to accept.

The doubters included not a few physicists, as a result of which an alternative interpretation was born. In 1965, a Princeton University graduate student named Hugh Everett proposed his Many Worlds Interpretation. According to this interpretation, when the lid of the box containing Schrödinger's Cat is opened, the indeterminate world of the unopened box splits into two worlds—one world in which the cat is alive, and another world in which the cat is dead. These two worlds have the same past, and their present at this point in time, when the lid is opened, differs only in whether the cat is alive or dead (but the future of these two worlds may follow a different course). These parallel worlds exist in infinite numbers, and because each of us can see only one of those worlds, we can experience no more than one outcome.

This sounds like science fiction, but it actually makes certain aspects of the quantum world easier to interpret, and should not be dismissed as mere amusement or prank.

The quantum world contains many, many more such amazing possibilities.