On 29th November 1935 Erwin Schrödinger published his famous paper on his thought experiment examining the paradox behind the Copenhagen interpretation of quantum mechanics.
In this thought experiment, a cat is placed inside a sealed box along with a radioactive substance, a Geiger counter, a vial of poison, and a hammer. The experiment is set up in such a way that if the radioactive substance decays, the Geiger counter detects it, causing the hammer to break the vial of poison, ultimately killing the cat. However, the decay of the radioactive substance is a random event and cannot be predicted with certainty.
According to quantum mechanics, until the box is opened and observed, the cat is considered to be in a superposition of states, simultaneously alive and dead. It is only when the box is opened and observed that the superposition collapses into one of the two possible states: the cat is either alive or dead.
The purpose of this thought experiment is to highlight the peculiar nature of quantum mechanics, where particles can exist in multiple states at the same time until they are observed or measured. It challenges our common-sense understanding of reality and raises questions about the nature of observation and measurement in the quantum world.
Not long after the Covid lockdown was lifted, Claire and I went to see Michael Frayn’s play Copenhagen at the Theatre Royal in Bath. It is based on a meeting between Neils Bohr and Werner Heisenberg in Copenhagen in 1941. Heisenberg was a key figure in the development of Quantum Mechanics and is best known for his Uncertainty Principle. We had ordered interval drinks which (because of Covid) I had to collect from the bar and take back to our seats. I must admit that the end of the first act did feel like an ending, and as I made my way to the bar probably more that half the audience were leaving the theatre saying how much they’d enjoyed the play. One woman protested to the men in her group that people seemed to be collecting drinks. “Oh no, that was definitely the end!” her husband replied. How brilliant I thought to write a play about Heisenberg and include an uncertainty in the structure of the play.
I thought this post was a good excuse for posting a cat picture. The internet loves cats and I might sell some books.