Very few felines have made such a lasting impression on popular culture (and have been a butt of many jokes) as the one commonly referred to as “Schrödinger’s cat.”
The Austrian physicist Erwin Schrödinger (1887–1961) earned the 1933 Nobel Prize in Physics for his work on quantum wave mechanics, but his name is most often associated with the thought experiment involving a cat—one which is simultaneously alive and dead. August 12, 2018, marked the 131st anniversary of the physicist’s birth, and last month Trinity College Dublin celebrated the 75th anniversary of Erwin Schrodinger’s historic, paradigm-shifting What is Life? lectures, reminding the world of the enduring impact of his work.
Before Schrödinger developed the cat experiment, another prominent physicist of the day, Niels Bohr, came up with an idea that became known as The Copenhagen Interpretation. It centers on quantum superposition—the term used to describe how quantum particles exist in all states simultaneously and can be in more than one place at a time. Essentially, this hypothesis holds that all particles exist as waves of probability; they don’t have a defined position until a measurement (i.e. observation) determines where they are.
Albert Einstein rejected this approach, arguing that the moon exists whether or not a mouse is looking at it. Schrödinger didn’t agree with Bohr’s interpretation either, so in 1935, he countered with his famous cat paradox.
He devised a theoretical experiment, where a cat was placed in a locked steel box, along with a radioactive atom, a Geiger counter, and a flask of poison. He suggested that if even a single atom of the poison decays, the counter will release it, and the cat would die. But, while the box is closed, we have no way of knowing for sure what the cat is doing or what its state is, so we assume it is living and dead at the same time. Only when we unlock the box and peer inside, would the cat be either dead or alive, but certainly not both.
(By the way, you can rest assured that no cats were harmed during this experiment since it was theoretical rather than real. If you own a cat, however, don’t attempt to do this experiment at home!)
If you are still not sure about how to interpret Schrödinger’s experiment, listen to this very clear explanation offered by the online science series, Minute Physics:
Even though Schrödinger’s cat was just a figment of the physicist’s imagination, the fact that the feline remained a part of mainstream culture for nearly eight decades proves one thing: that the cat is very much alive.
