DE Weekly: Schrödinger’s Cat, Nausea, & Reality
Below is an archived email originally sent on February 3, 2025.
Schrödinger’s Cat, Nausea, & Reality
Across philosophy and other mediums such as science, people have invented and relied on thought experiments to explain certain concepts and demonstrate different layers to a problem.
In quantum mechanics, one such thought experiment is “Schrödinger’s cat”.
Schrödinger’s cat concerns superposition. It was conceived by physicist Erwin Schrödinger in 1935, in a discussion with Albert Einstein.
In the thought experiment, a cat, a flask of poison, and a radioactive source are placed in a sealed box.
If radioactivity is detected (i.e. an atom decays), the flask is shattered, the poison is released, and the cat is killed.
There’s no guarantee this will happen, though. All elements inside the box–cat included–could coexist. Because of this, the cat can be considered both alive and dead, without opening the box to see which it is. Its fate is linked to an event that may or may not occur.
Schrödinger was attempting to explain the issues he saw with the Copenhagen interpretation of quantum mechanics, which implied that the cat is simultaneously both alive and dead.
When the thought experiment is viewed this way, it’s a paradox. Two things are true at once depending on how you look at it.
However, this view of things could be shattered by simply opening the box; once the box is opened, you’d see that the cat is not simultaneously alive and dead, but either alive or dead.
In quantum mechanics, the question this thought experiment poses is when quantum superposition ends and when reality resolves into one possibility or the other.
I’m not a physicist, so I won’t speculate on that question in particular. However, this thought experiment has a philosophical angle to it, too. Namely, an existential angle.
Schrödinger’s cat explores whether something can exist in two states at once. In philosophy, this can be explored through views on reality and consciousness.
Here’s one question we could ask in studying this thought experiment: Do I exist?
Let’s take that question a tad further. Do I exist in more ways than one?
If these questions are unsettling, they should be. They’ve been the subject of countless theories and essays of the greatest existentialist authors for years.
Even for the most well-written existentialists, Jean-Paul Sartre for one, these questions caused genuine fear.
In his first novel, Nausea, Sartre narrates from the first person perspective of a man named Roquentin writing in his diary to illustrate this very fear. The result of looking too much into this question is a feeling of sickness–of nausea–hence the name of the book.
In Nausea, Sartre writes, “My thought is me: that's why I can't stop. I exist because I think… and I can't stop myself from thinking. At this very moment - it's frightful - if I exist, it is because I am horrified at existing. I am the one who pulls myself from the nothingness to which I aspire.”
In the book, Roquentin struggles with his own existence. He doubts it, and doubts the existence of the people and objects around him. Because of this, he perceives existence as meaningless. Not only that, he’s also repulsed by the concept.
Sartre’s Roquentin (and perhaps Sartre, himself) suffers at the thought of his own existence. Perhaps the problem is Roquentin lives too much inside his own head.
A theme in the book and, indeed, a theme in many of Sartre’s works, is that one reason reality and our existence causes us so much distress is that it must be negotiated with other people.
For Sartre, the conscious observer–Roquentin, for example–is always determining the true state of reality for himself. For Roquentin, the cat is simultaneously alive and dead. Nothing is certain.
Schrödinger sought to posit through the example of his furry friend that reality is not a “blurred model”. He sought to disprove Sartre in this sense.
Here’s what I think.
I think up to a certain point, Sartre is correct. In any moment, anything can be true; however, this is only true itself until proven otherwise.
Let’s say I have a dear friend who’s just gone in for surgery. It’s a risky surgery–we’ll call the odds of survival 50/50.
As I sit in the waiting room, all realities are available to me in my mind.
On the one hand, the surgery is going excellently. My friend will live.
On the other hand, the body simply can’t take it. My friend will die.
Until the doctor emerges from the operating room to deliver the news, all realities are true at once.
Once I have a verdict, however, this is no longer the case. Once the situation reaches this point, Sartre ceases to be correct. Schrödinger is now correct.
Whether I know the state of something or not, it is not two things at once. It can’t be. It is one or the other––either it is or it isn’t. There is certainty in this. The same certainty Roquentin found, in a way, at the end of Nausea.
To hearken back to René Descartes, as long as I think I exist, I exist. To contemplate my own existence should not be a paradox, nor should it bring reality into question. I exist to me––I exist.
“I exist.’ In thousands of agonies — I exist. I’m tormented on the rack — but I exist! Though I sit alone in a pillar — I exist! I see the sun, and if I don’t see the sun, I know it’s there. And there’s a whole life in that, in knowing that the sun is there.” –– Fyodor Dostoevsky, The Brothers Karamazov
Thanks for reading.
Sincerely,
Brandon J. Seltenrich
P.S.––
Thought experiments are a great exercise to explore the machinations behind some of the conclusions drawn by the existentialists. Past this one, here’s a few more I’d recommend to check out: The Ship of Theseus and Plato’s Allegory of the Cave.
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