There is a longstanding interpretation of quantum physics in which a measurement conducted by an observer has the mysterious ability to “collapse” a probability wave function into a single measurement result. Whether this is a correct interpretation of quantum physics or whether the consciousness of the observer plays a role here is not a matter of agreement among physicists and philosophers. However, what does seem clear is that some form of interaction between the subatomic quantum world and the macroscopic classical world results in the probability distribution of a quantum wave function resolving into one unique, observable result. What is also clear is that a conscious observer, e.g., a scientist running an experiment in a lab, has the ability to produce an interaction that will resolve a quantum wave function into a unique measurement outcome.
Can a conscious observer collapse the wave function? Yes.
The result has been observed empirically, and it can be reproduced in a lab. Wave function collapse (also called state-vector reduction or quantum state reduction) is an established behavior of the quantum wave function when interacting with the macroscopic world through a conscious observer.
Is human consciousness required to collapse the wave function? Probably not.
The macroscopic universe and quantum state reduction have been around for 13.8 billion years; our earliest human ancestors arrived a mere 7 million years ago. Given these timeframes, it is unlikely that a human observer is required to collapse the wave function.
Quantum state reduction resolves quantum probabilities into unique outcomes. It transforms an array of co-existing possibilities with different probability amplitudes into a unique outcome, a distinct moment in time. The universe has managed this process without us for billions of years.
The macroscopic universe is manifestly not a place of co-existing possibilities in superposition. It is a place of actualities and events comprising macrocosmic history—the universe exploded; galaxies were born; stars and star systems evolved; we and perhaps others like us came into existence. All of these events occurred in a particular way because of a constant process of wave function collapse and transformation.
What does that tell us? It tells us that, in addition to physicists in a lab, there are other things or processes in the universe with the capacity to perform the magic.
The wave function has been performing the magic for billions of years
It is an empirical reality that some form of interaction between the macroscopic classical world and the microscopic quantum world results in quantum state reduction. This process has been going on since at least the Big Bang, and we have hypothesized that it serves as the underlying engine of time. Somehow the transformation from microcosmic quantum superposition into macrocosmic unique reality takes place.
We don’t have a full understanding of how this process happens. We don’t know if macroscopic interaction truly “collapses” the wave function or if what we describe as “collapse” is the result of some other process in the universe, such as the splitting of reality into “many worlds” in which all possibilities play out. We know only that there exists a process in the universe whereby interaction between the macrocosmic and quantum worlds causes probabilities to become outcomes, producing a stream of moments that we know as time and history. This process is at the core of macrocosmic existence. It is what the universe does.
The ability of the universe to perform this process without the interference of humans is not a matter of reasonable scientific doubt. The open question is not whether human consciousness is required for quantum state reduction. Clearly it is not. The real question is whether this universal process is required for consciousness.
Is quantum state reduction required for consciousness?
In the broad sense, the answer to this question must be yes. The macrocosmic universe as we know it would not exist without quantum state reduction, so we humans and human consciousness also would not exist.
However, does consciousness require quantum state reduction in a more functional sense as well? Does the process of consciousness require quantum interaction either at the neuron or subatomic level inside our brains? Could there be a continuing process of quantum state reduction occurring in the brain that enables the distinctive, noncomputable qualities of consciousness?[1]
Is the wave function the origin of consciousness?
The jury is still out on whether quantum interaction plays a role in the physical functioning of the human brain. But perhaps the answer is simpler than that. Could there be a more ontological connection between the universal process of quantum state reduction and the process of consciousness? Does the ability of a conscious observer to perform quantum state reduction in a lab suggest a taxonomical connection?
The process of resolving probabilities into outcomes is perhaps the most fundamental process in the universe. Is it also the most essential attribute of consciousness? At a physical level, is human consciousness a species or instantiation of the universal process of resolving probabilities into outcomes?[2]
Is process consciousness?
Quantum state reduction occurs every nanosecond in the macrocosmic universe. We exist because of it. We are also part of it. Our human consciousness is one of many processes in the universe that resolve probabilities into outcomes. We are built as decision-making entities to survive through the choices we make and the actions we take. Does the process of making choices perform the equivalent of quantum state reduction? Do our choices resolve probabilities into outcomes that then shape more probabilities and more outcomes? Is the process of consciousness part of a more universal process of becoming that has its roots in the microscopic quantum world?
If that is so, can consciousness be generalized to comprise any process that constitutes a resolution of the wave function into an outcome? Is that the abstract, most generalized definition of consciousness?
Is the process of quantum state reduction itself the functional and ontological equivalent of consciousness?
[1] Physicist and mathematician Roger Penrose and neuroscientist Stuart Hameroff have developed an ingenious theory called Orchestrated Objective Reduction (or Orch OR), which builds on Penrose’s theories around the objective nature of quantum state reduction to construct a model of brain behavior and the development of consciousness based on quantum interactions. For a review of the current status of the theory and related empirical research, see Hameroff and Penrose (2014). For a detailed discussion of possible quantum interaction in the brain and non-algorithmic, noncomputable ingredients in thought and consciousness, see Penrose (1989), pp. 516-581, and Penrose (1994).
[2] Penrose and Hameroff argue that the objective process of quantum state reduction (Objective Reduction or OR) results in moments of proto-consciousness in the universe. These events are hypothesized to have “rudimentary subjective experience, which is undifferentiated and lacking in cognition”, but which serve as raw materials that can be orchestrated through evolution of more complex brain interactions to create full-blown consciousness. Hameroff and Penrose (2014), p. 72.
