In a world increasingly characterized by the belief that each person’s truth holds equal validity, it might not be entirely erroneous to consider that “truth” is a weighted combination of our individual perspectives. The scientific method, with its three pillars of observation, measurement, and repetition, has long been our compass in the quest for truth—a quest that lies at the very heart of human endeavor. Traditionally, this journey has been anchored in the conviction that facts, once unearthed, stand as unassailable and universal. Yet, this bedrock of objectivity may be less solid than we presumed, especially within the enigmatic realm of quantum mechanics. Here, our conventional wisdom about the irrefutability of facts is not just questioned but may be fundamentally altered.
At least in the quantum realm, a recent ground-breaking discovery that was published in Science Advances [1] has completely upended the idea of objective truths. This result may have significant effects on our understanding of reality itself, making it more than simply a minor quirk of the subatomic realm.
Quantum Complexity: Where Subjectivity Meets Science
The observer effect, a basic feature of quantum physics, is the study’s pivot. Particles can exist in multiple states simultaneously, a phenomenon known as superposition. However, the act of observing forces the particle to ‘choose’ a specific state. This peculiar aspect has been demonstrated repeatedly, notably in the double-slit experiment. Building on Eugene Wigner’s 1961 thought experiment, the researchers proposed a test to see if facts are indeed subjective in the quantum realm. Wigner posited a scenario where an observer’s reality does not match the external one due to the quantum state’s superposition. Extending this to an experimental setup, the researchers utilized a quantum computer and entangled photons to represent Wigner’s friend scenario.
Experimental Evidence
The experiment involved pairs of entangled photons, with measurements made both inside and outside their ‘boxes.’ Astonishingly, the results violated the Bell inequality, a cornerstone of quantum mechanics that, if contravened, suggests that objective reality might not be as solid as it seems. The theory presupposes that no faster-than-light communication occurs and that observers can freely choose their measurements. If these assumptions hold, the implications are staggering: we may live in a world where objective facts are not a given but are observer-dependent.
At the core of the actual interpretation of quantum mechanics are those three key cornerstones:
- The reality of observed events: We tend to believe that once an event is observed, it has definitively occurred.
- Free will in making choices: It’s commonly thought that individuals can make free or random choices.
- Locality: the idea that an event here cannot instantaneously affect an event somewhere else.
The paradox presented by the recent quantum experiment [1] suggests that these assumptions cannot all be true if we fully accept the predictions of quantum mechanics.
The Philosophical Repercussions
What does this mean for our search for truth and our understanding of reality? At the macroscopic level, where our daily lives unfold, facts seem secure. But the quantum underpinnings of our universe suggest that subjectivity might be woven into the fabric of reality itself. This has given rise to diverse interpretations. Some physicists speculate about multiple universes where every possible outcome is realized. Others lean towards observer-dependent theories, like quantum Bayesianism, which places the observer’s experiences at the core of reality. These findings prompt a crucial question: does quantum mechanics hold up under the weight of complexity, or will it crumble, necessitating a new framework for understanding the universe?
So, what we know is that people base their “truth” on their own observations, experiences, and interpretations. This phenomenon is both sociological and psychological. For instance, two individuals may see the same occurrence, but their memories or interpretations of it may differ, resulting in disparate “truths” or accounts that they accept and narrate. This subjectivity is not directly related to quantum phenomena; rather, it is a well-known feature of human cognition. In quantum experiments, the “subjective realities” aren’t interpretations; rather, they’re actual variations in a quantum system’s state brought about by various interactions or measurements. The theory goes that, in the quantum world, the process of measuring itself contributes to the knowledge of the subject’s condition. The parallel fails to hold true when considering the intricacies of the human experience, as human experiences are not as isolated as quantum systems and are not equally susceptible to randomness (see also Ref. [2]).
The Battle for Reality
Quantum mechanics suggests that until a particle is measured, properties like position and velocity are not definite but probabilistic. This was counterintuitive to Einstein, who, along with Podolsky and Rosen, suggested that quantum mechanics was incomplete because it didn’t account for what they considered to be the “hidden variables” that would determine these properties definitively.
John Bell later showed through his inequalities that if the hidden variables existed and locality was maintained, certain statistical correlations couldn’t be as strong as quantum mechanics predicted. Experiments have shown that quantum predictions hold, suggesting that these properties really don’t exist until measured (non-realism) and that entangled particles are somehow connected beyond the traditional confines of space and time (non-locality). Thought experiments such as Wigner’s friend illustrate the strange role of the observer in quantum mechanics. It suggests that an observer becomes entangled with the system they’re observing, leading to a situation where different observers cannot agree on a single, objective reality.
What does it all mean? If the quantum mechanical predictions continue to hold as the scale of the experiments increases, we might have to accept one of several radical possibilities:
- Objective Collapse Theories: Quantum mechanics may break down at larger scales or higher complexities, leading to an objective reality that emerges above the quantum level.
- Non-locality: instantaneous connections across space, which conflict with Einstein’s relativity.
- Superdeterminism or retrocausality: These suggest either a predetermined universe or effects that can travel backward in time.
- Relational Reality: Reality might be observer-dependent, meaning that events are only real relative to each observer.
Conclusion
Even while reality may be relational, interactions and communication among observers might result in a shared, complex reality. This means that although quantum mechanics can cast doubt on our traditional ideas of objective reality, it does not, in a social or psychological sense, give people the right to select their own empirical reality. In the end, the profundity and intricacy of quantum mechanics, along with its philosophical ramifications, prompt us to contemplate the possibility that the foundations of our reality may differ significantly from our common sense perceptions and instincts. And as our research into the macroscopic world continues, who knows? We might discover that each person’s life experience indicates a distinct reality, yet one that is undoubtedly closely related to the truths of others.
The lessons learned from quantum physics have profound importance in today’s world of conflict and misunderstanding. Particle entanglement at great distances is a metaphor for our interdependence as a global society, where decisions made in one area can have an instant impact on another. Although they have their roots in the real struggle for power or resources, wars and conflicts are also fights over narratives and realities that are believed to exist. Misunderstandings often arise not from the facts themselves but from different interpretations and the weight given to them by diverse observers. If we are to navigate this world of disorder, it may serve us well to acknowledge that while there are objective truths to be found, our perception of them is invariably colored by the context in which we experience them. It is through dialogue and a willingness to understand the perspectives of others that we can hope to construct a shared reality that leads to peace and mutual understanding.
REFS:
[1] Bong, KW., Utreras-Alarcón, A., Ghafari, F. et al. A strong no-go theorem on the Wigner’s friend paradox. Nat. Phys. 16, 1199–1205 (2020). https://doi.org/10.1038/s41567-020-0990-x
Link here.
[2] Gearoid Hayes, “Quantum physics: our study suggests objective reality doesn’t exist“.
Mario J. Pinheiro
Science2be 