Erwin Schrödinger was born in August 1887 in Vienna, Austria. He was a pretty ordinary guy, although his abilities were anything but ordinary. Some people have a knack for knitting, others an aptitude for aviation… Good old Erwin happened to be a master of quantum physics.
His career is rife with astounding scientific advances, but Schrödinger is most known for his ill-fated feline. Although most people do not realize the meaning and implications behind this world famous thought experiment – Schrödinger’s Cat.
Is it anything more than imaginary animal abuse by a crazy old Austrian guy?
Before that question can be answered, you need to understand what is going on in the experiment itself.
Schrödinger thought up a theoretical situation (keyword: theoretical… So no animals were harmed in the making of history) in which a cat was locked in a box with a vial of poison gas, a hammer, a sample of radioactive material and a Geiger counter.
He stipulated that the radioactive material has a 50/50 chance of emitting radiation, in which case the Geiger counter would detect said radiation, trip the hammer which would smash the vial of poisonous gas, and the cat would die. In short, there was a 50% chance that the cat would die and a 50% chance that the cat would live.
The outcome – alive or dead – can only be determined when the observer opens the box and looks at the cat.
This seemingly strange and cruel thought experiment is a fantastic illustration of a fascinating quantum mechanical phenomenon – superposition.
Superposition is a concept which says that an object with multiple possible states is simultaneously in every single one of its states until it is observed, at which time it collapses into only one of its possible states.
In the context of Schrödinger’s cat, the cat is in a superposition of alive and dead while in the box, and the act of opening the box causes our feline friend to collapse into one of his two states – alive or dead.
In other words, before we look at the cat, he is alive and dead at the same time, and the act of looking at him causes one or the other to become true.
I know what you are thinking. Sounds pretty idiotic, right? And just plain impossible… If you are thinking these things, then give yourself a pat on the back because you are one smart cookie.
Superposition is a quantum mechanical phenomenon, and quantum mechanics only governs things on the atomic level.
Macroscopic things, such as cats, obey the laws of classical physics, which do not allow absurdities such as a zombie cat which is both alive and dead at the same time.
Tiny things, on the other hand, are governed by quantum mechanical laws including superposition.
One such tiny thing – the electron – has many possible states.
When observed, electrons are in one definitive state, but beforehand the phenomenon of superposition takes over. Scientists have seen multiple evidences of superposition on the sub-atomic level such as single electrons being in multiple places at once.
The discovery of this seemingly magical physics phenomenon has led the way to multiple new breakthroughs in the world of quantum physics, and has paved the way for today’s scientists to continue to rewrite scientific history.