While at a performance of Copenhagen - Michael Frayn's hit play about Niels Bohr¹ and Werner Heisenberg² - I suddenly found myself thinking about the similarities between predestination and Schroedinger's cat³.

Copenhagen deals with a meeting which took place between Neils Bohr and Werner Heisenberg in Copenhagen, Denmark in 1941. In the nineteen-twenties, the two great physicists had worked closely together on the nature of matter - developing quantum mechanics. At that time, Neils Bohr was the professorial mentor but also the friend, colleague and sparring partner for the young Heisenberg. In 1927, Werner Heisenberg developed and became famous for his Uncertainty Principle, so becoming in his own right a pillar of the international physics community.

I could write at length about the play and its explorations of quantum mechanics which it applies to Heisenberg's life. But suffice to say that one of the quantum analogies explored in the play is Schroedinger's cat³ which he described in a famous 1935 paper⁴.

Schroedinger's cat is the famous quantum cat which is trapped in a box and which may or may not be dead. It remains in a state of uncertainty - even confusion - until the curious Schroedinger opens the box where upon, instantly, the quantum cat is revealed as dead or alive.

The quantum cat passes from the indeterminate state of being dead or alive to the determinate state of being dead (or alive!). Quantum physics says that the quantum cat is not revealed as always having been dead or always having been alive. It says rather that it is the act of opening the box which collapses the quantum state-vector which describes the state of the cat. Many people did not like that idea when it was first proposed by Schroedinger, but eventually modern physics had to accept it even though it flew in the face of common sense - even Schroedinger seems to have found it an uncomfortable conclusion⁵.

As the cat was mentioned, my mind leapt from science to faith and from Schroedinger's cat to predestination. Predestination - the great question of old - do we live pre-determined lives which the all-knowing God has planned for us? Or do we have free-will, so free that even God can never know what we will do at any moment of our lives.

There have been some who argue that we must come down on one side of the argument or the other - either we have free will or we are robots controlled by God. Common sense says you can't have it both ways. Just as common sense says that Schroedinger's cat is dead or alive - not both.

But the world of physics eventually had to accept that the state of Schroedinger's cat (dead or alive) is inherently undetermined - not just unknowable - until the box is open. And even today the quantum cat of modern physics defies our mundane laws of common sense⁶.

So too with predestination. From one vantage point (looking to the future) we have free-will. From another (looking back) we can see how God had hold of us at every point of our lives. Both ideas can be true because the realities of God's world (like the realities of the quantum world) are not bound by our mundane laws of common sense.