Schrödinger’s Cat: What Is It?

(Picture Credit: Getty Images)

(Picture Credit: Getty Images)

You may have heard the term “Schrödinger’s Cat” referred to in party conversation or vaguely remember from high school physics class. Schrödinger’s Cat is quite famous, and it is alive. Schrödinger’s Cat is dead. It is both until you confirm it. Confused? Here’s everything you need to know about Schrödinger’s Cat.

Erwin Schrödinger was an Austrian physicist who won the Nobel Prize for his work on quantum theory back in 1933. His thought experiment, Schrödinger’s Cat, was created to challenge the Copenhagen Interpretation of quantum superposition.

For readers who are not physicists, here is a very diluted explanation of quantum superposition: particles at the quantum level (see: incredibly, practically impossibly, small) aren’t in one state. They are changing between a variety of states and exist across all of these states at the same time. 

The constantly-in-flux-and-everywhere-at-once particle stays in this superposition until the particle is measured or observed. At this point, the particle will stay in a fixed state or position. This, according to the Copenhagen Interpretation, is how particles function at the quantum level. 

This is where Schrödinger’s Cat comes into play.

Schrödinger’s Cat was a thought experiment designed to challenge that notion. What if something more substantial, say an entire living creature, was thrown into the mix? Could that change whether or not the subatomic particles would be in superposition as described above?

Imagine a cat inside of a box with a contained poison. The poison is set to be given to the cat based on the radioactive decay of a subatomic particle. 

Now, these are the particles that were discussed before. These particles are both in decay and not decaying at the same time, given that they are in superposition according to the Copenhagen Interpretation. Since these tiny subatomic particles are always in flux, there is no knowing whether or not the poison has been released and the cat is dead, or if the poison has not been released and the cat is still alive. Therefore, by the Copenhagen Interpretation, the cat is both alive and dead until observed. The “fate” of the cat would be determined once somebody finally opened the box and observed the cat. 

The whole purpose of creating Schrödinger’s Cat was to show that yes, the nature of subatomic particles seems to be random, but ultimately, a cat is not a subatomic particle and therefore cannot be in superposition. The cat would have to be either alive or dead, not a weird always-changing-half-zombie-cat-half-alive-cat.

In short, Schrödinger’s Cat was a thought experiment designed to show how ridiculous it is to consider quantum states for larger objects.  Schrödinger’s Cat has made its way into pop culture, especially in comics and science fiction, and many people reference it when discussing a situation with an unknown outcome. 

Had you heard of Schrödinger’s Cat before? Do you think Schrödinger’s Cat could possibly be both alive and dead? Let us know your quantum theories in the comments.