Whose Reality Is It Anyway?

Thomas Nagel wondered if the world a bat perceives is fundamentally different  to our own

By Keith Tidman

Do we experience the world as it objectively is, or only as an approximation shaped by the effects of information passing through our mind’s interpretative sieve? Does our individual reality align with anyone else’s, or is it exclusively ours, dwelling like a single point amid other people’s experienced realities?

 

We are swayed by our senses, whether through the direct sensory observation of the world around us, or indirectly as we use apparatuses to observe, record, measure, and decipher. Either way, our minds filter the information absorbed, becoming the experiences funneled and fashioned into a reality which in turn is affected by sundry factors. These influences include our life experiences and interpretations, our mental models of the world, how we sort and assimilate ideas, our unconscious predilections, our imaginings and intuitions unsubscribed to particular facts, and our expectations of outcomes drawn from encounters with the world.

 

We believe that what serves as the lifeline in this modeling of personal reality is the presence of agency and ‘free will’. The tendency is to regard free will as orthodoxy. We assume we can freely reconsider and alter that reality, to account for new experiences and information that we mold through reason. To a point, that’s right; but to one degree or another we grapple with biases, some of which are hard-wired or at least deeply entrenched, that predispose us to particular choices and behaviours. So, how freely we can actually surmount those preconceptions and predispositions is problematic, in turn bearing on the limits of how we perceive the world.

The situation is complicated further by the vigorous debate over free will versus how much of what happens does so deterministically, where life’s course is set by forces beyond our control. Altering the models of reality to which we clutch is hard; resistance to change is tempting. We shun hints of doubt in upholding our individual (subjective) representations of reality. The obscurity and inaccessibility of any single, universally accepted objective world exacerbates the circumstances. We realise, though, that subjective reality is not an illusion to be casually dismissed to our suiting, but is lastingly tangible.

In 1974, the American philosopher Thomas Nagel developed a classic metaphor to address these issues of conscious experience. He proposed that some knowledge is limited to what we acquire through our subjective experiences, differentiating those from underlying objective facts. To show how, Nagel turned to bats’ conscious use of echoed sounds as the equivalent of our vision in perceiving its surroundings for navigation. He argued that although we might be able to imagine some aspects of what it’s like to be a bat, like hanging upside down or flying, we cannot truly know what a bat experiences as physical reality. The bat’s experiences are its alone, and for the same reasons of filtering and interpretation, are likewise distinguishable from objective reality.

 

Sensory experience, however, does more than just filter objective reality. The very act of human observation (in particular, measurement) can also create reality. What do I mean? Repeated studies have shown that a potential object remains in what’s called ‘superposition’, or a state of suspension. What stays in superposition is an abstract mathematical description, called a ‘wavefunction’, of all the possible ways an object can become real. There is no distinction between the wave function and the physical things.

While in superposition, the object can be in any number of places until measurement causes the wavefunction to ‘collapse’, resulting in the object being in a single location. Observation thus has implications for the nature of reality and the role of consciousness in bringing that about. According to quantum physicist John Wheeler, ‘No ... property is a property until it is observed’, a notion presaged by the philosopher George Berkeley three centuries earlier by declaring ‘Esse est percepi’ – to be, is to be perceived.

Evidence, furthermore, that experienced reality results from a subjective filtering of objective reality comes from how our minds react to externalities. For example, two friends are out for a stroll and look up at the summer sky. Do their individual perceptions of the sky’s ‘blueness’ precisely match each other’s or anyone else’s, or do they experience blueness differently? If those companions then wade into a lake, do their perceptions of ‘chilliness’ exactly match? How about their experiences of ‘roughness’ upon rubbing their hand on the craggy bark of a tree? These are interpretations of objective reality by the senses and the mind.

Despite the physiology of the friends’ brains and physical senses being alike, their filtered experiences nonetheless differ in both small and big ways. All this, even though the objective physical attributes of the sky, the lake, and the tree bark, independent of the mind, are the same for both companions. (Such as in the case of the wavelength of visible light that accounted for the blueness being interpretatively, subjectively perceived by the senses and mind.) Notwithstanding the deceptive simplicity of these examples, they are telling of how our minds are attuned to processing sensory input, thereby creating subjective realities that might resemble yet not match other people’s, and importantly don’t directly merge with underlying objective reality.

  

In this paradigm of experience, there are untold parsed and sieved realities: our own and everyone else’s. That’s not to say objective reality, independent of our mental parsing, is myth. It exists, at least as backdrop. That is, both objective and subjective reality are credible in their respective ways, as sides of the whole. It’s just that our minds’ unavoidable filtering leads to the altering of objective reality. Objective reality thus stays out of reach. The result is our being left with the personal reality our minds are capable of, a reality nonetheless easily but mistakenly conflated with objective reality.

 

That’s why our models of the underlying objective reality remain approximations, in states of flux. Because when it comes to understanding the holy grail of objective reality, our search is inspired by the belief that close is never close enough. We want more. Humankind’s curiosity strives to inch closer and closer to objective reality, however unending that tireless pursuit will likely prove.

 

On Quanta and Trees

Does Observation Create Physical Reality?

Image found on Mythapi Facebook page. Author unknown

Posted by Keith Tidman

The intervention of conscious observation into the quantum world — that observing an object to be in a particular location causes it actually to be there — is one of the core tenets of quantum theory. A tenet rigorously upheld through multiple experiments. The observer — his or her consciousness — cannot be separated from that physical reality. There is no reality independent of observation. 

As the visionary quantum physicist John Wheeler stated it, “No . . . property is a property until it is observed.” Which seems to apply as much to macro-sized objects — things in everyday life — as to micro-sized objects.

Three hundred-plus years ago, the philosopher George Berkeley prefigured the spirit of quantum theory’s then-future influence on the nature of reality, declaring, esse est percepi [to be is to be perceived]. Perception, he presciently advocated, is the essential benchmark — the necessary condition — for existence. The reality of things thus emerges from perception. As long as conscious observation is involved — a manifestation of the observer's capacity to consummate physical reality — all objects, large and small, acquire their existence.

So, how does this work? Quantum theory explains that until observation occurs, a potential object was in what’s called a state of ‘superposition’. An object, while in superposition, can be in any number of places, with observation causing it to be in just one location. There was no object isolated in space before it was observed or measured. Upon being observed, the object went from potentiality to actuality in that one location, the same for everyone.

What’s in superposition is the so-called ‘wave function’ — a mathematical description of all the possible states of an object. Only upon being observed does the wave function instantaneously and irreversibly ‘collapse’, causing the object to be in just one location. There is no distinction between the wave function and the object. According to the physics, the wave function is the object — in one-to-one correspondence with the physical thing.

The effect of observation and measurement has also been demonstrated by the so-called ‘double-slit experiment’. A stream of photons (light particles) passes one at a time through a screen with two slits. Behind the screen is a photographic plate, to capture what comes through the slits. In the absence of an observer, each photon will have appeared to pass through both slits simultaneously before creating a distinct interference pattern on the back plate — acting, in other words, like a wave, able to pass through both slits at once. However, in the presence of an observer — a person or detecting device in front of or behind each slit to see which slit the photon goes through — the interference pattern no longer shows up. Each photon appears to have passed through only one slit or the other. The photon has no location in spacetime until it’s observed or measured.

As suggested by both examples — the collapse of a wave function and the double-slit experiment — observation may be performed by a person directly and in real time. Or, observation may be accomplished by an apparatus (detector), whose measurements are observed by scientists later. In either case, observation remains critical, as explained by physicist and philosopher Roger Penrose:

“Almost all the interpretations of quantum mechanics . . . depend to some degree on the presence of consciousness for providing the ‘observer’ that is required [for] the emergence of a classical-like world.”

Meanwhile, the effects of these events also play into what’s known as quantum entanglement — what Albert Einstein famously dubbed ‘spooky action at a distance’. Quantum entanglement occurs when two particles remain ‘connected’, without regard to time and distance — that is, instantaneously, even at enormous distances — in such a way that actions performed on one particle are observed to have an immediate and direct effect on the other. This curious phenomenon, spooky or not, has been confirmed.

So, to the point, what does all this tell us about physical reality?

Causing the reality of an object by observation points to this initial moment of creation being subjective. It’s where an observer first intervenes — until which there is only ‘potential reality’. Accordingly, ‘initial reality,’ as we might call it, requires intervention by an observer — either a person or measuring device. Again, that initial moment of reality is subjective.

However, once initial conscious observation has occurred, the object henceforth exists for everyone. Further instances of observation change nothing about the physical reality already having been created. Reality is thus locked in for everyone — everywhere. Everyone who looks will find the object there, already existing. At that moment, reality is objective — the initially observed object remains so, existing for everyone.

In sum, then, the key takeaway is the presence of both a subjective and objective aspect to reality, depending on the moment — initial observation followed by subsequent observation.

At the moment of causing the object to exist, the observer also causes that object’s entire history to exist. Observation causes both the current reality and related past realities (history) to exist. Whether this is so for literally all observed things remains debatable — quantum mechanically, cosmologically, and philosophically.

Might the notion include, for example, the whole universe — the ultimate macro-sized object? As Wheeler postulates, in our looking rearward to the universe’s beginnings, might our observations result in selecting one out of alternative possible cosmic quantum histories, back to the Big Bang almost fourteen billion years ago? And, in line with the ‘anthropic principle’, might that quantum history account for the many finely tuned features of the universe essential for its and our existence — resulting in an objective macro-reality, the same for everyone, throughout the universe?

Accordingly, Berkeley argued that observation accounts for what gives material things their experienced qualities — an object’s initially experienced reality (its presence and qualities) as well as an object’s subsequently experienced reality.

Where Berkeley’s philosophy converges with the core of this discussion regarding the basis of objects’ reality is his argument for observation — perception — being essential for something to exist. What has been characterised as Berkeley’s empirical idealism. Berkeley argued that material objects are dependent on, not independent of, observation. In this important sense, observation and existence are the same. That is, they ‘cohere’.