Is Reality Incomplete? Exploring the Question of Ontological Incompleteness in Quantum Mechanics

Discussing the nature of reality using Copenhagen interpretation, many-worlds theory, Bohmian mechanics, and objective collapse theories.

At first, we had mathematical axioms, and we understood matter. Then, we had Newtonian Physics, and we understood gravity. Then, we had the Einstein revolution, and we understood space and time. Then, we had quantum physics, and we realised that we understood nothing (not completely anyway). The universe has long captivated human curiosity with its mysteries, but none have proven more perplexing than the enigma presented by the realm of Quantum Physics.

As we discovered the intricate world of subatomic particles and elusive forces, the familiar laws that governed our macroscopic world seemed to unravel, revealing a landscape filled with uncertainty and ambiguity.

And as we discovered more and more about the strange yet amazing world of Quantum Physics, Philosophers, Physicists and thinkers landed on an important question: is reality ontologically incomplete within the domain of Quantum Physics?

In this article, we shall try to explore this question in-depth. Spoiler alert - there is no conclusive answer to this question as of yet. What you will find however, through the course of reading this article, is that the answer (whatever it maybe) is more nuanced and textured than one might have thought.

Artwork - The Ontological Incompleteness of Reality

But first, a quick (non-optional) Quantum Physics crash course

To understand the question of ontological completeness within the realm of Quantum Physics, it is essential to first acquaint ourselves with the fundamental principles that govern the domain. But don’t worry, I won’t be boring you with all the details. Instead, I will briefly explain three important concepts of Quantum Physics that are necessary to understand for the sake of this article.

Superposition

In the quantum realm, particles such as electrons, photons, and atoms do not possess well-defined states in the way we are accustomed to in our macroscopic world. Instead, they exist in a state of superposition, wherein they can inhabit a multitude of possible states simultaneously. This ethereal state of affairs allows for the coexistence of contradictory possibilities, blurring the lines between what we consider as distinct realities.

Uncertainty Principle

The uncertainty principle asserts that certain pairs of complementary properties, such as an object's position and momentum, cannot be simultaneously known with infinite precision. The more accurately we know one property, the less accurately we can know the other. This inherent limit to our knowledge underscores the indeterminacy woven into the fabric of the quantum universe, where measurement itself becomes an act of revelation, exposing one aspect of reality while leaving others shrouded in ambiguity.

Wave-Particle Duality

The wave-particle duality proposes that entities such as electrons and photons exhibit both particle-like and wave-like behaviours depending on the context of observation. This duality illustrates the inherent complexity of the quantum world, where the very nature of particles seems to shift and morph, challenging our notions of fixed identities.

And that’s it. We are done with the basics of Quantum Physics required for this article. Just one last thing.

What is Ontological Completeness?

To make this simple, let us first understand what is ontology and then define the meaning of ontological completeness with regards to Quantum Physics.

Ontology

Ontology is a philosophical branch concerned with the study of existence, reality, and the nature of being. It delves into questions about what exists, what kinds of things exist, and how different entities relate to each other and the world around them.

Ontological completeness / incompleteness

In the context of Quantum Physics, the terms "ontological completeness" and "ontological incompleteness" refer to philosophical questions about whether our current understanding of the quantum realm provides a comprehensive and exhaustive description of the underlying reality or whether there may be deeper layers or aspects of reality that are not fully captured by our current theories.

Ontological Completeness

If Quantum Physics were considered ontologically complete, it would mean that the theory provides a complete and accurate description of the fundamental nature of reality at the quantum level. In other words, there would be no additional hidden variables, unobserved properties, or deeper layers of reality beyond what is described by Quantum Physics. Everything that exists and occurs in the quantum realm would be accounted for within the framework of the theory.

Ontological Incompleteness

On the other hand, if Quantum Physics were considered ontologically incomplete, it would suggest that there are aspects of reality, properties, or mechanisms that exist or operate in the quantum realm that are not currently explained by our theories. This could imply that our understanding of the quantum world is limited or that there may be hidden variables or underlying principles that have yet to be uncovered.

Okay, done! You now understand what is Quantum Physics, why it makes people question reality, and what we mean when we say Quantum Physics is ontologically complete / incomplete.

Now let’s get to the meat of the article. How Physicists and Philosophers interpret Quantum Physics and what conclusions they draw from it about the nature of reality.

Interpretations in Physics

First, let us consider what Physicists derive from Quantum Physics about the nature of Reality. These interpretations provide lenses through which we can view the quantum world, each offering its own perspective on the nature of reality and its potential ontological completeness or incompleteness.

The Copenhagen Interpretation

Among the most well-known and historically significant interpretations is the Copenhagen interpretation. Named after the city where it was formulated, this interpretation asserts that a quantum system exists in a superposition of states until it is observed or measured. Only through this act of observation does the system "collapse" into a definite state, thereby conjuring a concrete reality from the realm of probabilities. This view leads to the intriguing notion that the act of observation plays a fundamental role in defining the nature of reality, suggesting an inherent connection between the observer and the observed.

Many-Worlds Interpretation

In stark contrast to the Copenhagen interpretation, the Many-Worlds interpretation proposes a radically different perspective on the quantum realm. According to this view, all possible outcomes of a quantum event are realised, but they occur in separate branches of the universe. This implies that every choice, measurement, or interaction spawns a branching of realities, each following its unique trajectory. While this interpretation offers a solution to the enigma of wave function collapse, it also introduces a multitude of parallel universes, raising questions about the nature of observation and the unity of consciousness. I intend on discussing this in further detail in a future article.

Bohmian Mechanics

Bohmian mechanics, another interpretation, introduces the concept of hidden variables—unobservable quantities that influence the behaviour of quantum systems. In this view, particles possess definite positions and trajectories, even in the absence of observation. This interpretation challenges the probabilistic nature of Quantum Physics, suggesting a deterministic reality beneath the surface of uncertainty. However, it also brings forth questions about the nature of these hidden variables and their compatibility with the principles of Quantum Physics.

Objective Collapse Theories

Objective collapse theories propose that wave function collapse is not dependent on observation but occurs spontaneously due to a certain physical process. These theories introduce mechanisms that lead to the reduction of the wave function, collapsing it into a definite state. While these ideas offer potential solutions to the measurement problem, they also raise inquiries about the nature of the triggering process and the implications for our understanding of reality.

Interpretations in Philosophy

Now that we have a lay of the land in Physics’s interpretations of reality in the quantum realm, let us explore some thoughts by philosophers in this regard.

Bohr and Einstein’s Dialogues on Reality

Both Bohr and Einstein were primarily physicists. But their debates on Quantum Physics also had a philosophical bend that’s worthy of mention. In the early days of Quantum Physics, Niels Bohr and Albert Einstein engaged in spirited debates that illuminated the philosophical implications of the quantum enigma. Einstein's skepticism about the completeness of Quantum Physics led to his famous quote, "God does not play dice with the universe," reflecting his unease with the probabilistic nature of the theory. Bohr, on the other hand, championed the idea that Quantum Physics provided a complete description of reality, emphasising the role of complementarity in embracing the dual nature of particles.

Consciousness and the Observer

The question of consciousness inevitably emerges as we contemplate the mysteries of Quantum Physics. The observer's role in defining reality—whether through the collapse of the wave function or the act of measurement—raises tantalising questions about the nature of consciousness itself. Could it be that consciousness plays a foundational role in shaping the world, blurring the lines between the external universe and our inner perceptions?

Eastern Philosophy and Quantum Insights

The parallels between Quantum Physics and Eastern philosophical traditions have not gone unnoticed. Concepts such as interconnectedness, non-duality, and the interplay of observer and observed resonate with ideas found in ancient wisdom traditions. Some philosophers and scholars have explored these connections, suggesting that Quantum Physics offers a bridge between scientific inquiry and the contemplative insights of Eastern thought.

Limits of Human Perception and Measurement

A huge part of the problem, when it comes to theorising the nature of reality in the quantum realm, is our own limitations in perceiving it. As such, the problem not only lies with our understanding of the universe but also with our limitations in acquiring the needed data and interpreting its findings.

Heisenberg's Uncertainty Principle

This principle asserts that there is an inherent limit to the precision with which we can simultaneously measure certain pairs of properties, such as position and momentum. This bound on knowledge highlights a fundamental trade-off between our ability to ascertain one aspect of a quantum system with accuracy and our knowledge of another aspect, casting a shadow of uncertainty over our attempts to unveil the true nature of reality.

Quantum Measurement

Quantum measurement itself is a delicate interplay between the quantum system being observed and the instruments used for measurement. The very act of measurement can perturb the system, leading to an inherent imprecision that stems from the interaction between the observer and the observed. This raises questions about the objectivity of measurement and the role of the observer in influencing the outcomes.

Epistemic and Ontological Uncertainty

These limitations not only challenge our ability to precisely measure quantum properties but also raise profound questions about the nature of reality itself.

Epistemic uncertainty refers to our limitations in acquiring knowledge about reality due to the constraints of measurement, while ontological uncertainty speaks to the inherent ambiguity embedded in the quantum world. Together, these uncertainties beckon us to contemplate the potential incompleteness of our understanding and the elusive nature of a reality that seems to defy our classical intuitions.

So….is Reality Ontologically Complete?

The answer - depends on which theory you subscribe to. If you go by the Copenhagen interpretation, then reality in the quantum realm is ontologically incomplete, as only by the act of observation do we derive deterministic states. If you go by the Many Worlds interpretation, then the universe becomes infinitely complex thereby making the question of ontologically completeness a moot point. If you consider Bohmian Mechanics that challenges the probabilistic nature of the quantum realm, then reality in the quantum realm has to be complete in order for the theory to hold.

So far, the philosophical response to the notion of ontological incompleteness in the quantum realm has been underwhelming. While I completely understand the urge to bridge the gap between philosophical intuition and scientific inquiry, the understanding of reality in the two fields remains fundamentally different. Furthermore, there is also the question of wether such a unification brings with it, any utility?

What do you (the reader) think about the nature of reality? What are your thoughts about the quantum realm? Do let me know in the comments. Also if you haven’t already, make sure to subscribe to receive more such articles.