Was Schrödinger ever a determinist?

The Great Cosmic Dice Roll

Imagine the universe as a giant, ticking clockwork machine. For centuries, scientists believed that if you knew exactly where every gear was and how fast it was spinning, you could predict exactly what would happen next, forever. This idea is called determinism: the belief that the future is already written by the past, like a movie that has already been filmed and is just waiting to be played. But then, in the early 20th century, a new kind of science called quantum mechanics arrived. It suggested that at the tiniest level, nature doesn't work like a clockwork machine at all. Instead, it behaves more like a roll of dice, where you can only predict the chances of something happening, not the result itself. This shift from "certain fate" to "random chance" shook the world of physics to its core.

One of the most famous scientists of that era, Erwin Schrödinger, is often remembered as the guy who hated this new idea. He is famous for a spooky thought experiment involving a cat that is both dead and alive at the same time, and many people think he used it to show how silly quantum randomness was. But what if we've been reading the story wrong? What if the man who wrote the famous equation that describes how quantum waves move was actually the biggest fan of the "dice roll" universe all along? This question matters because it changes how we see the history of science and forces us to ask: Is the universe truly random, or did we just miss the clues for a hundred years?

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The Misunderstood Rebel

For a long time, history books have painted Erwin Schrödinger as a grumpy old guard, a "reactionary" who refused to let go of the old ways. Along with other big names like Einstein, he is often grouped with the scientists who fought against the revolutionary idea that nature is fundamentally random. The story goes that Schrödinger was desperate to prove that the universe was still a smooth, predictable machine, just like the clockwork models of the past.

But this new paper suggests that this famous story is a bit of a mix-up. The authors, Flavio Del Santo and Nicolas Gisin, argue that Schrödinger wasn't fighting against randomness; he was actually one of its earliest and most radical champions. While his famous equation (which describes how particles move as waves) looks very smooth and predictable, Schrödinger himself spent much of his life arguing that the universe is actually a chaotic, statistical mess. He wasn't trying to save determinism; he was trying to tell everyone that determinism was never real to begin with.

The Three Arguments for Chaos

The paper digs into Schrödinger's old essays, particularly one called "Indeterminism in Physics," to show that he had three clever reasons for believing in randomness, even before quantum mechanics became the standard.

1. The "Perfectly Precise" Lie
First, Schrödinger attacked the idea that we can ever know the starting point of anything perfectly. In the old "clockwork" view, if you knew the exact speed and position of a ball, you could predict exactly where it would land. Schrödinger argued that this is just a mathematical trick, an "artifice." He pointed out that assuming you can measure speed with infinite precision is impossible. In reality, even in classical physics (the physics of everyday things), identical starting conditions don't lead to identical results; they only lead to the same statistics or patterns. It's like trying to predict the exact path of a leaf falling in a storm; even if you think you know the wind perfectly, the tiny, unmeasurable wiggles mean the outcome is always a bit of a surprise.

2. The Broken Clock and the One-Way Street
Second, he looked at how things change over time. The old view said nature follows strict, reversible laws (if you played a movie of a planet orbiting backward, it would still make sense). Schrödinger argued that nature is actually full of "discontinuity" and "irreversibility." He called the belief in strict laws a "philosophic prejudice" or an "ancient custom" that scientists just refused to let go of. Instead, he suggested that the laws of nature are more like a "game of chance." He pointed out that most things in nature are one-way streets (like an egg breaking; it never un-breaks), which suggests that the universe isn't following a strict, pre-written script, but rather rolling dice at every step.

3. The Finite Information Limit
Finally, Schrödinger made a mind-bending argument about information. He suggested that nature might be made of a finite number of "yes-or-no" answers, like a string of 0s and 1s (bits of information). He argued that if nature had to describe every single detail of the universe with infinite precision, it would require an infinite amount of information, which is impossible. Since nature has a limit on how much information it can hold, it can't possibly be a perfectly detailed, deterministic machine. Instead, it must be a bit fuzzy and random. This was a very forward-thinking idea, anticipating the modern concept of "information theory" decades before it was officially named.

The Radical Truth

The paper concludes that Schrödinger's view was actually much more radical than we realized. While modern scientists who believe the universe is a giant, unchangeable wave (called "Everettians") use his equation to prove that everything is deterministic, Schrödinger himself might have been rolling his eyes at that idea. He believed that the "indeterministic" nature of physics was obvious long before quantum mechanics was discovered.

The authors suggest that Schrödinger's true genius was seeing that the universe was never a clockwork machine to begin with. He was part of a group of scientists in Vienna who were taught that "everything that happens in nature is the result of random events." The paper argues that we have been misreading Schrödinger for a century, thinking he was the villain of the randomness story, when in fact, he was one of its most vocal heroes. He didn't just accept the end of determinism; he was trying to tell us that determinism was a myth all along.