Since the birth of quantum mechanics at the beginning of the 20th century, the idea of chance has become almost mythical in the field of physics. On the microscopic scale of electrons around atoms or photons hitting a detector, the results seem to obey purely probabilistic laws: we can only predict chances, never a precise event with certainty. However, some physicists believe that this theory is incomplete and that it only reflects the limit of our understanding.
According to this intuition, there would be a fundamental structure, deeply buried, which would determine the outcome of each event, even those that we believe to be random. This would mean, summarizes Popular Mechanics, that these rules not only govern physical phenomena, but also influence the fate of our lives, both happy and unhappy.
For Timothy Palmer, professor of climate physics at the University of Oxford, the problem comes not from reality, but from the mathematics we use to describe it. In a recent article submitted to the journal Proceedings of the Royal Society, he puts forward a radical idea: not all of the mathematically possible states allowed by quantum theory exist in the real world. In other words, we must stop confusing what the equations allow us to imagine with what nature actually makes possible.
Quantum mechanics today is based on the idea of a continuum: a set of perfectly continuous numbers, without “holes”, among which we can always find an infinity of values between two points. This mathematical world includes numbers like π or √2, which can never be written exactly but are nevertheless omnipresent in equations. Timothy Palmer rejects the idea that this continuum accurately describes reality: according to him, the observable universe never needs infinitely precise numbers and these values only add possibilities that do not exist in nature.
The end of Schrödinger’s cat
This intuition is not entirely new. Physicists like Dutchman Gerard ‘t Hooft have already suggested that quantum behavior could emerge from deeper, deterministic laws, even if it appears chaotic on the surface. Carlo Rovelli, a major figure in quantum gravity, explored the idea that the structure of space-time breaks into finite units at the ultimate scale. What sets Timothy Palmer apart is how far he pushes this: in his work, he doesn’t just criticize the continuum, he asserts that certain hypothetical scenarios simply don’t exist. If we remove them, some of the quantum strangeness fades: even Schrödinger’s famous cat would no longer be both alive and dead, but in a single, well-defined state.
The same logic applies to chance. In the standard vision, a particle does not follow a determined trajectory: the theory gives probabilities – 80% for one result, 20% for another – which are verified if the experiment is repeated a large number of times. But for a single event, here and now, quantum mechanics offers no deeper reason: why this result rather than the other? It provides no answer.
Timothy Palmer thinks that “there might be a reason” even for this singular event: for him, “the world is really deterministic…it looks random, but it’s not”. What we call chance would be the reflection of a structure that we do not yet know how to see.
An invisible “guide”?
The idea that a system can follow strict rules while giving the illusion of chance may seem paradoxical, but physics already knows it. With chaos theory, a field in which Timothy Palmer has worked for decades, we know that systems governed by precise laws – such as the atmosphere – can produce unpredictable behaviors beyond a certain horizon. The weather obeys equations, but remains impossible to anticipate long in advance: the uncertainty comes more from extreme sensitivity to initial conditions than from a cosmic draw.
Other researchers have pushed the idea of a hidden order even further. David Bohm developed a fully deterministic interpretation of quantum mechanics, in which particles follow precise trajectories guided by an invisible “pilot wave.” Sabine Hossenfelder, a theoretical physicist known for her work on the foundations of physics, believes that quantum theory mainly describes sets of results, not events taken one by one, and that it is ultimately a “theory of averages”. She diverges from Palmer on several points, but shares one conviction: reality is a matter of cause and effect, not pure chance.
It remains to be seen how to test this vision of our universe. Timothy Palmer suggests turning to quantum computers, precisely designed to exploit the uncertainty that his theory calls into question. In principle, these machines should outperform classical computers on certain problems, such as factoring very large numbers, thanks to qubits that can explore multiple states simultaneously. But Palmer predicts that this exponential advantage will eventually break down: if all mathematically possible quantum states don’t actually exist, then a quantum computer won’t be able to access the entire landscape predicted by theory, and its performance will plateau beyond a certain number of qubits.
If, on the contrary, quantum computers continue to gain power as physicists anticipate, Timothy Palmer’s idea will collapse. Sabine Hossenfelder remains skeptical: if a fundamental ceiling were revealed, it would be “the greatest breakthrough in physics in a hundred years”she says, but she doubts it will happen. For now, the question remains open: will the next generations of quantum processors confirm standard predictions, or will they reveal cracks in the structure?
The physics of the very small has withstood every experimental test for more than a century, making it one of the strongest theories ever developed. But if the experiment were to reveal limits where quantum mechanics does not expect them, the consequences would be dizzying. For if chance is not fundamental, then what we call luck might just be a provisional term for a deeper structure that we have not yet discovered.
