Thought experiments are famous for a reason. They’re fun tools that simplify scientific concepts without involving much of the unwieldy math. In essence, they are springboards to rigorous scientific discussion, using intuition first and mathematics and experimentation after. But therein lies the catch: intuition. Like with any field, common people who are not involved in the said field often do not have the intuition of professionals. What makes sense in an instant to an expert may be completely nonsensical to a random passerby.
Enter Erwin Schrodinger and his cat-in-a-box. Well, imaginary cat. People online discussing the “Schrodinger’s Cat” thought experiment talk about it without knowing what it really was. No, it’s not about “multiple universes” or whatever else that science fiction and superhero movies want people to believe. It was Schrodinger criticizing Quantum Physics, specifically the concept of superpositioning in Quantum Mechanics. He likened the “absurdity” of the then-emerging field to how nonsensical a cat is simultaneously alive AND dead unless observed.
What makes sense in an instant to an expert may be completely nonsensical to a random passerby.
But what is superpositioning? In Quantum Mechanics, it is posited that for a quantum particle (particles as small as or smaller than an electron), you can’t know the absolute state (position OR momentum, change in energy OR change in time, and other conjugate pairs or properties of the particle) of a particle UNTIL it is observed and measured. Afterward, that particle will always have that measured state and nothing else. Until said particle is observed, the particle exists in a “superposition” (that is, of a set of different states occurring simultaneously) of different, sometimes conflicting, states.
Prior to the 1960s, most of the world’s top physicists believed that quantum particles behaved in the same way as observable objects and followed the rules of classical mechanics. Classical Mechanics is the physics of anything bigger than an electron, from whole atoms to entire galaxies. It is through Classical Mechanics that we know how fast a car, a spaceship, or even planets, are going, because it is through Classical Mechanics that the behavior of things we can readily observe with our naked eyes are modeled. For example, if you throw a basketball into the hoop, its position and momentum can be measured simultaneously because the ball can be accurately observed (i.e. you can see the ball leave the hands of the player and fly in an arc towards the hoop). Keyword: observed.
Particles that are electron-sized and smaller cannot be accurately observed. For example, in an atom having a certain level of energy, electrons are bound within “clouds of probability” (also known as Atomic Orbitals in Atomic Chemistry), meaning that there is a high chance of finding said electron within the cloud-shaped volumes around the nucleus, and very little (very close to zero) chance of finding an electron outside said clouds. THAT is the nature of Quantum Physics and Quantum Mechanics: quantum particles cannot be accurately observed and measured. In fact, knowing about them is mostly statistics, a game of chance.
In their great, collective wisdom, the top physicists of the world were so against statistics. They had always thought that Physics was the “Science of Certainty.” Schrodinger certainly thought so. That’s why he was against the emerging field of Quantum Mechanics. For him, thinking that an electron exists or doesn’t at a certain place is based on chance—only “partially knowable” until it is observed—is as ridiculous as thinking that a cat that is simultaneously dead AND alive until it is observed. Think of it this way: a basketball thrown into the hoop can’t both be speeding towards the target AND be perfectly still, suspended in the air, AT THE SAME TIME. Yet, Quantum Mechanics posits that quantum particles exhibit such behavior.
Do you know who else was against Quantum Mechanics? Albert Einstein. Mr. Einstein was so big on the “Science of Certainty” aspect of Physics that he often spoke or wrote about the ridiculousness of Quantum Mechanics. “God doesn’t play dice with the universe.” Contrary to Christians often quoting that without context, it isn’t about Einstein admitting that he is a believer. Rather, it was a criticism of the statistical nature of Quantum Mechanics. Read it like this: “The rules of the universe are not reliant on chance.”
However, it is quite unfair to paint the physicists of the 19th and 20th centuries as scientific “boomers” who are too set in their ways. Nowadays, the understanding of Quantum Mechanics has powered technologies from cell phones to MRI machines to space missions. However, in the late 1800s and early 1900s, ALL of known Physics obeyed the laws of Classical Mechanics. There is some uncertainty in Classical Mechanics, sure, but it could be boiled down to flaws or shortcomings in the calculation, and not down to chance (e.g. the Butterfly Effect). When Niels Bohr, Werner Heisenberg, and their colleagues proposed that the behavior of quantum particles is reliant on observation and chance, the physicists of that era were right to be suspicious. They did not have the findings that we have today. After all, any new idea should both withstand criticism and show experimental results which agree with it. In the 1920s, the early forms of the Copenhagen Interpretation (the brainchild of Bohr, Heisenberg, and others) showed mathematical promise, but there was little way to prove it experimentally. Thus the doubt.
So, no, Schrodinger’s Cat isn’t about “multiple universes” or “50% chance of being alive or dead,” nor is it an actual experiment or a gateway to higher technologies or dimensions. It was Schrodinger misinterpreting Quantum Mechanics. Nowadays, Physicists acknowledge Schordinger’s point—that it is ridiculous for an object to exhibit contrasting properties until observed—but they also acknowledge that it is simply how the rules of the “quantum world” work. There is, after all, no use arguing with reality. However, and more importantly, Schrodinger and his thought experiment is a testament that any idea, any new piece of knowledge, should be put to the rigors of scientific criticism and investigation before it is considered as part of the truth. Sure, he may have been wrong in the long run, but he did what any respectable scientist would have done: examine thoroughly before accepting as fact. Instead of the “multiverses” or whatever else, perhaps it’s that ‘need for a thorough examination’ that we really should get out of Schrodinger and his cat.
