The Takeaways:
- The foundation of unified quantumology — the ultimate reason the laws of quantum physics can be applied to particles and all the way up to the Universe — is a system of superpositions throughout scales, sizes, and time.
- Superposition is ontology, meaning it is the way reality exists and state multiplicity holds for all matters in space-time, from rocks to human societies, in the forms of composition– and population– based superposition. The former applies to a single entity while the latter to a collection of entities.
- One way to link state multiplicity in superposition and Darwinian natural selection is that the former provides the diversity needed by the latter, while the latter in turn shapes states that are the “fittest” in the former.
- The measurement problem is solved once we stop viewing realized and unrealized possibilities of states as mutually exclusive. During any measurement only one set of states reveals itself, while other sets will appear in future measurements or more likely reveal themselves through a mixed blend of multiple underlying states, much like purple is a blend of red & green.
- We can understand measurement issue through notions of “genotype,” “phenotype” and “gene expression.” At each moment of measurement, we see one phenotype corresponding to one predetermined complex genotype, one specific but dynamic blueprint of gene expression, and one specific dynamic set of environmental conditions. Each phenotype is shaped by three sets of states: environment, genotype, and gene expression, each of which has its own superposition of states. The coexistence of multiple states explains why different measures produce different results, even for selfies.
A Crucial Question about Quantum Weirdness
This excellent essay by theoretical physicist Marcelo Gleiser published in Big Think inspires me to write this post. It asks what exactly quantum mechanics means: Is it pure mathematical models or truly reflecting reality?
Normally a question like that does not warrant serious scientific attention because a model that does not reflect reality, no matter how beautiful it may look, has little value other than aesthetically pleasing.
Yet if we look at the huge discrepancy between the world of the very smalls and the world of macroscopics, the above question makes total sense. Gleiser reminds us that quantum physics is not a simple matter of right or wrong because “it describes the experiments incredibly well” but when we turn to the familiar world, things change right away. “We do not think of people or rocks being in more than one place at the same time until we look at them. They are where they are, in one place only, whether we know where that place is. Nor do we think of a cat locked in a box as being both dead and alive before we open the box to check. But such dualities are the norm for quantum objects like atoms or subatomic particles, or even larger ones like a cat.”
This is what defines quantum weirdness: Something works beautifully at one level and yet not even imaginable at another.
Either the reality itself is weird, or could the theory be weird?
Gleiser is smart to focus on superposition of multiple states, although his key question for today may not be accurate. “The crucial question that still haunts or inspires physicists is this: Are such possible states real — is the particle really in a superposition of states — or is this way of thinking just a mathematical trick we invented to describe what we measure with our detectors?”
I would say at the particle level the issue is settled and there are ways to prove superposition is real, such as interference patterns in a double slit experiment. It is superposition for the macroscopics that is still questionable.
Before we can settle the cross-level consistency issue, before the discrepancy between, say, the “states of rock” and states of particle can be fully explained away, we are not entitled to claim that the same laws of quantum physics apply to particles and universe equally well.
Gleiser believes fundamental mindset change is necessary, as he said in another essay that you “might have to give up believing everything you thought to be true about something.”
He is right about mindset change. But do we need to give up believing everything we thought to be true? We may not have to. I am here to argue that no such dramatic change is necessary, as we can demonstrate that superposition is everywhere and all the time in the world we are familiar with — we just have to open our minds to it.
A Look at Metamorphic Rocks
Since Gleiser used the immobility of rocks as an example of normal things not existing in multiple states at the same time, let’s follow up on that chain of thoughts. Rocks seems to offer “rock solid” evidence supporting the Newtonian physics: They always stay where they are, they maintain the same look, and they retain the properties they were born with.
But do they really? Looking closer and deeper, facts of rocks may surprise you, as they do have multiplicity of states in superposition. To understand how, read this entry from National Geographic called “Rock Cycle.” It tells us that “rocks, a seemingly constant substance, can change into a new type of rock.”
Consider this type called metamorphic rocks that undergo changes to a new rock. It is one of the three types (with sedimentary & igneous). Unlike the other two, metamorphic rocks began as rocks and then, due to various conditions within the Earth, they were changed into a new kind of metamorphic rock.
“The conditions required to form a metamorphic rock are very specific. The existing rock must be exposed to high heat, high pressure, or to a hot, mineral-rich fluid. Usually, all three of these circumstances are met. These conditions are most often found either deep in Earth’s crust or at plate boundaries where tectonic plates collide. In order to create metamorphic rock, it is vital that the existing rock remain solid and not melt. If there is too much heat or pressure, the rock will melt and become magma. This will result in the formation of an igneous rock, not a metamorphic rock.” says the National Geographic article.
But here is the thing: there must be times when the heat and pressure are such that a metamorphic rock will become half-way between magma and solid, moving toward being an igneous rock. Such a state is a superposition of states when a metamorphic rock exists as both solid and magma — or neither solid nor magma, just like purple reflects the coexistence of color red and color blue.
Rock Weathering and Erosion
If the above is too subtle, takes too many turns or is limited to one type of rock, an easier example that applies to all rocks on the face of the Earth is weathering and erosion. According to this website, “weathering has helped shape the landscape. Weathering wears away rocks and soil” through wind, water, ice, plants, gravity and changed temperature.
For example, rainfall water becomes ice in cold season and expands in rock cracks and eventually splits the rock. Tree roots do the same. Erosion then takes over from there. “As pieces of the Earth are broken down by weathering, they are carried away in a process called erosion.”
So here we have it: At any point of time, a rock exists in the state of solid whole but also in many broken pieces. The latter differ in size but also in location, because smaller pieces are ready to be eroded away and landed somewhere else by wind, rain, and gravity. In that sense, a permanently immobile rock is just an illusion, attracting (or distracting) our attention when its small siblings — the other state of existence — fly away all the time, in all directions, and to all places.
Besides, no rock is permanently immobile because we will have mudslides or mountain slides that will dramatically or quickly dislocate rocks, many of them at a time.
But let’s go back to the slow motion of the changing world. Ever noticed rocks with a smooth surface or shaped like a mushroom? It is a safe bet that not all mushroom rocks were born that way but gradually formed by weathering and erosion. The mushroom shape therefore presents the visible evidence of the rock being in a superposition of states, with the small pieces being everywhere and barely detectable.
Rethinking Schrödinger’s Cat
Rocks are inorganic and not capable of moving by themselves, but organic and living things do. Speaking of living things, nothing is more exciting than Schrödinger’s cat, a thought experiment devised in 1935 by the famous physicist Erwin Schrödinger that illustrates a paradox of quantum superposition.
Let’s quote Wikipedia to get a quick start: “In the thought experiment, a hypothetical cat may be considered simultaneously both alive and dead, while it is unobserved in a closed box.” It also tells us that “Schrödinger did not wish to promote the idea of dead-and-live cats as a serious possibility; on the contrary, he intended the example to illustrate the absurdity of the existing view of quantum mechanics.”
But Schrödinger’s cat contains the same problem as Gleiser’s rocks: They look at a macroscopic object in their whole, when they should have broken it down to its compositions.
The cat in the box — in fact, all living things for that matter — are constantly in a superposition of live and death throughout their lives, whether inside a sealed box or in a widely open space, with or without the poison.
The Lesson of Compositional Superposition
The key is to recognize what may be called “compositional dual states” or composition-based superposition of states. At any moment, some cells of our body or a living thing are dying or dead while others are coming to life or growing. The body as a whole gradually moves from more “live” to more “dead” as we age, until one day we will be pronounced medically dead. Poison, cancer, accidents & unhealthy livings will all speed up the process toward death — all though weakening, damaging or killing body compositions.
Other lessons from Schrödinger’s cat include that superpositional states are ontological, meaning they were the original property at the birth of all matters, not something learned or acquired later in life. For living things we need to go down to cells and find superposition there. Non-living things don’t have cells, but they do contain atoms and molecules.
At least for living things we can also link superposition of states with natural selection: The former provides diverse raw materials for the latter, which in turn shapes the survival rate of different states.
Reconsidering the Measurement Problem
Now let’s consider the so-called measurement problem in quantum mechanics. Gleiser asks if all the states of a particle are real — or only the one observed in a measurement is real.
My answer is simple and applicable not just to particles but everything in the Universe: All superpositioned states, observed or not during a single measurement, are real. In fact, this is not much different from casino games: Both the (small) possibility of winning and the (large) possibility of losing in a casino are real — although at each game we either win or lose, not in between.
Consider weather forecast, where we hear conditions like certain percent (80, 60, 50, 40, 30, 20 or 10) chance of rain all the time. Both “rain” and “shine” are real conditions. Just because the day was raining non-stop, and we did not see the sun at all does not mean the 20% shine or no rain was fake. The same goes for 60% rain (and 40% no-rain) or anything in between. If we look at a single day, we see the chance of rain changing sometimes by hours. The point is that we do not use observed outcomes to reject the existence of possibilities, because the latter allow more diversity than the former at any point of time.
From Human Selfies to Phenotype Variation
Let’s consider human examples that are easier to understand for most. Everyone can take selfies using a smartphone. Each selfie of you is as real as you are, although some selfies you like more than others, and some selfies may even surprise yourself (“How can I look so ugly?”).
But why do we produce different selfies using the same smartphone and with the same object, yourself, on separate occasions or days? Aren’t we supposed to look the same over a brief period like in a year? The answer to this simple question is more complicated than you think.
To fully understand why all states (or selfies in this case) are real, let’s borrow a few terminologies from genetics, where we have genotype, phenotype, and gene expression. Genotype (or more generally genome) refers to the genetic makeup of an organism, which includes the specific alleles that an individual possesses for a particular gene. Non-living things don’t have genes or cells, but they do have atoms and molecules in their compositions. Phenotypes are the observable characteristics or traits of an organism, which are influenced by both genetic and environmental factors.
Gene expression is something different. It is not a part of genotype or phenotype, but a process that links the two by which genetic information encoded in DNA is used to produce functional products such as RNA molecules and proteins and determine the phenotypes of organisms. It is like an on/off switch to control when and where RNA molecules and proteins are made, as well as a volume control to determine how much of those products are made.
Now, bear in mind that a human body is a highly sophisticated package with an estimated 70,000 genes collectively called the human genome within each of about 100 trillion cells, except for the red blood cells that contain no nucleus and no nuclear DNA. Each gene can range from as few as 100 DNA bases to as many as several million.
One direct consequence from having so many cells and genes is the rich variety of hereditary instructions to all new cells, amplified by genes interactions (i.e., the joint role of multiple genes in determining phenotypic variability) and gene expression that constantly adjusts functional genetic blueprints in response to environmental conditions. The result is a superposition of phenotypic states in different selfies and pictures.
Phenotypic variation across selfies seldom shows as qualitative differences but more within a quantitative spectrum — once again more like the color schemes: With the additive RGB (red, green & blue) primary colors, we can add the three colors until they become white. With the subtractive RYB (red, yellow & blue) primary colors, we can add them until they become black.
Another way to put it is that each selfie is a measurement of a phenotype but due to genotypic variety, gene expression variation and environmental variation, there will be different copies of phenotype, not just one, although at one point of time only one will show up. Each phenotypic copy is as real as others, and each has a unique probability of showing up during a selfie measurement, which is more likely a blend of phenotypes, again just like slightly different blue or red or green or anything in between.