The Cat That Wouldn't Die

The famous Schrödinger’s Cat paradox, an interesting hypothetical situation reflecting the endless weirdness of quantum theory, was first introduced in just a short paragraph in a long academic article on quantum mechanics by Erwin Schrödinger to give non-academic readers a simple and understandable image of the theory. Now famous for its mystery that encourages our never-ending curiosity about human intelligence, the paradox did not gain as much popularity then as it has now.

The paradox is as follows: a cat is kept inside a box along with a mechanism that, if an atom of a radioactive substance kept inside decays, triggers a gun that shoots the cat dead. Since the probability of the atom’s decay is unpredictable, an observer cannot answer the question, ‘Is the cat alive or dead?’ until they open the box’s lid. As soon as the lid is opened, the state of the cat—whether alive or dead—emerges with certainty, but until that moment, as Erwin Schrödinger wrote, the cat is both alive and dead simultaneously.

It was quite simple up to this point. But as it raises a variety of ‘what if’ questions, the paradox, along with quantum mechanics, starts revealing the theory's weirdness. What if the observer is entangled with the system kept under the box—that is, there is a probability of opening the lid and seeing a dead cat and, again, opening the lid and seeing an alive cat? And what if the observer is kept in another box—maybe that is the reality we call our own? Or what if someone else is viewing this whole system, including the first observer?

Concepts like the multiverse—which imply that with every single incident, multiple universes are created, each having one of the possible event results—emerged after these questions, thereby making the theory of quantum mechanics seem incomplete, as Einstein once said.

Some scientists, like Niels Bohr, who helped establish the foundation of the theory, however, tend to view this situation as purely symbolic. Quantum mechanics, according to him, is nothing more than a computational device that helps us measure the possibility of any future event, and the cat, gun, or radioactive atoms are no more than symbols used just to represent it easily, having no relation to the real world we live in.

Now the choice is ours. Should we dismiss its weirdness and reluctantly keep quantum mechanics as it is, or should we dig deeper to find as many possibilities as the weirdness it has to offer?

This summary is based on Jim Baggott’s essay “The Cat That Wouldn’t Die” (Aeon), which explores the philosophical and scientific implications of Schrödinger’s cat paradox in the context of quantum mechanics. Main essay link: https://aeon.co/essays/no-schrodingers-cat-is-not-alive-and-dead-at-the-same-time