Physicists, philosophers, enthusiasts, and Marvel scriptwriters all love to imagine the so-called quantum world or quantum realm. This place is meant to represent the hypothetical experiences of a human that has been miniaturized to subatomic scales. While at times amusing, with questions like, “What’s it like to be entangled?” or “What does being in superposition feel like?”, the science doesn’t provide a tangible world one can step into to explore and answer these questions. There are two reasons why. One is obvious, and the other is much more subtle.
Honey, I Shrunk The Grad Student
The concept of shrinking a human, depicted in various science fiction scenarios, confronts numerous scientific, biological, and physical barriers — we’d have more than a few small problems. (Okay, fine, no puns.) Consider the square-cube law. If you shrink something by a factor of 1,000 in volume, the surface area only shrinks by a factor of 100. While it is often claimed that this would provide superhuman strength, it would probably simply halt all cellular functions and biochemical reactions in the body.
The way our lungs work is based on the diffusion of oxygen across membranes into our bloodstream. If our lungs were shrunk, the amount of oxygen they could intake would be drastically reduced, leading to insufficient oxygen supply for the body.
The brain is incredibly intricate, with about 100 billion neurons connected in a very specific pattern. Shrinking it while preserving its functionalities would be impossible, as altering the size and spacing of neurons drastically changes how the brain processes information. Even if it could maintain some function, you wouldn’t be you anymore since your brain encodes that information in its particular physical arrangements.
And, of course, there are countless more problems with this hypothetical scenario. In essence, while the concept of shrinking humans offers entertaining escapades in films and books, the reality is bound by laws of physics, biology, and chemistry that don’t permit such alterations without catastrophic consequences. Our bodies and all other matter are made up of atoms. Reducing the space between the atoms in our bodies would profoundly alter the chemistry of how our body works if they remained bodies at all.
I know what you are thinking, and I agree. But while I realize one needs to suspend disbelief to enjoy science fiction, many commentators still delight in arguments about the factual correctness of the science being depicted. More often than not, the questions are of a partially counterfactual nature where only some of the laws of physics are broken, and we are to consider the consequences for the remainder of them. Case in point: while the size of atoms is fixed by the laws of physics, which leave no room for shrinking them, we can simply pretend it’s possible and ask, “What if?”
The problem then would be in breaking our most fundamental laws. If all physical laws and other scientific ones that emerge out of them follow from the same foundation, and you choose to consider destroying that, then anything is possible. At that point, it’s completely arbitrary which rules are to be followed since they will all be broken. This is not meant to be an argument against science fiction — it is simply an argument that nothing can be learned about quantum physics this way.
If Not Down, Then Up
Let’s ignore biology and ask a more abstract question: supposing some conscious entity could experience the world at the atomic scale, what would it be like?
The exploration of conscious experiences, especially those outside our everyday perception, isn’t limited to physics. Philosophers, too, have delved deeply into the question of subjective experiences different from our own. Thomas Nagel, a prominent philosopher, raised this concept in his 1974 essay, “What is it like to be a bat?” Nagel argued that even if we can describe the biological processes and behaviors of a bat, we can never truly know what it’s like to be a bat because its experience is fundamentally different from our own. A modern popularizer of consciousness research, Anil Seth, echoed this point using an octopus — with its billion neurons not confined to a central brain, the octopus likely has an incomparable experience to our own.
Our consciousness is deeply tied to our sensations. Sight, touch, smell, taste, and hearing are the cornerstones of our understanding of the world around us. These senses are our blurry windows into reality, providing us with an imperfect but rich understanding of our environment. How would these senses translate at the atomic scale? In truth, they wouldn’t. At such a minute scale, the concepts of sight, touch, and the other senses as we understand them become irrelevant.
At the atomic level, interactions are governed directly by the four fundamental forces of nature. There’s no hearing because sound requires a medium (like air or water) to carry pressure waves. There’s no touch in the way we feel it since atoms never truly “touch” each other. There’s nothing to see because light can only resolve distances comparable to its wavelength. It would not “see” atoms as we like to visualize them in diagrams, for example. Taste and smell, which are based on chemical reactions and the interaction of molecules with receptors in our body, also don’t have parallels at the atomic level.
So, if a conscious entity were to exist at the atomic scale, its “experience” would be radically different from anything we can imagine, dominated by a world of direct interactions with fundamental forces mediated by quantum probabilities. This brings us back to the perplexing question: What would it be like? As with Nagel’s bats and Seth’s octopuses, it’s a question that might not have an answer. We can extrapolate, hypothesize, and philosophize, but the actual experience would be so alien and distinct from our human consciousness that it would fail to answer the real question.
What Is The Question?
All of these games are ultimately meant to help us understand quantum physics. In some sense, they have.
Imagine a flatworm, a creature that is often found in the dark. In fact, if you put one in a petri dish that is partially illuminated, you will likely find it on the shady side regardless of where it started. While we can make predictions about where we will find them and under what conditions, we always seem to crave a clear causal mechanism — the “why” behind their actions. Say we hypothesize that flatworms might move faster and with more direction changes when exposed to light. This would “explain” why it is usually found in the dark. If we were to conduct an experiment and confirm this, it would offer a clear rationale for their behavior in the previous experiments. But notice the seemingly innocuous assumption here: that the results of separate experiments are directly related in a neat, causal fashion. In essence, we’re drawing a line between separate dots, hoping they’ll form a clear picture.
Our map of the world is built upon countless such assumptions and connections. This intricate network forms the bedrock of our understanding of the world, lending coherence and predictability to our experiences. We, as humans, possess an innate drive to detect patterns, make associations, and predict outcomes — it’s a survival trait honed over millennia. This desire for clarity, for neatly drawn lines connecting the dots, is so deeply embedded that it’s often taken for granted. Yet, it’s a pivotal cornerstone in constructing our perception of reality. It shapes our thoughts, influences our decisions, and, to a large extent, defines our relationship with the world around us. It is the scaffold upon which we frame our reality and the lens through which we interpret it.
Quantum physics, however, throws a wrench into this elegant machinery. The outcomes we witness and the interpretations we derive are directly influenced by the questions we pose and the design of our experiments. There is no causal machinery behind what is observed at the atomic scale. Indeed, the very concepts we wish to consider are contextualized by the questions we ask, and these need not be related to the answers to alternative questions. The dots cannot be connected, and the network that defines our experience of reality dissolves. Quantum physics defies our innate drive for a stable, unified representation of reality. The quantum world, as we’d like to define it, doesn’t truly exist in any fixed sense. If you attempted to create a map of it, each new piece of information would not so much add to the map as it would erase or alter other parts of it. Instead of a world that you can visit and discover, it is an inaccessible realm. Nevertheless, it is a place where you can ask questions — a nebulous place where the answers are only defined once the questions are asked.
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Dr. Chris Ferrie