Two of the over eleven definitions of the word “understand” in The Merriam-Webster Dictionary.
- #2 : to accept as a fact or truth or regard as plausible without utter certainty <we understand that he is returning from abroad>
- #5 : to achieve a grasp of the nature, significance, or explanation of something
Summary: The following brief paper proposes that, of all the fields of scientific study, quantum mechanics has failed the most profoundly in being able to explain the nature of the phenomena it seeks to understand. And, while this is not a failure of the scientists investigating the world of the very, very small, it speaks to the quantum realm having more in common with the world of Harry Potter than it does of our collective understanding of “real things.”
Introduction: Two weeks ago this Sunday, a group of us had a discussion concerning whether we (or anyone, for that matter) really understands quantum mechanics.
On the pro-side of the argument was the statement, attributed to Richard Feynman, that “if you can build something, then you understand it.” Therefore, because we build all sorts of functional machines that use quantum mechanics as the basis of their design, then it must follow that we do, in fact, “understand” quantum theory and the quantum world. Another way of stating this (as I understand the argument) is that, by understanding the mathematics of how a thing functions, one understands, in some fundamental way, the thing itself.
The con-side of the argument (this author’s position), is that “understanding” anything dealing with the quantum world (see definition #5, above) is, for now at least, beyond our grasp. For example, to say some object has a “wave-particle duality” means that we know that this something acts in a certain way, but that we have no clear comprehension of, or agreement as to the how or why of the phenomena. Simply saying that something is the way it is because, well, dammit, that’s just the way it is, is an assertion, not a scientific explanation.
Another way of stating this position is that, like the classic cartoon in which two scientists are standing at a green-board, studying a set of equations, we need a better understanding of what exactly the miracle of “Step Two” is. And, so far as I understand quantum mechanics, a lot of people have many, many interesting ideas of what that “miracle” is, but very few agree…
The Nature of Science: Prior to the discovery of how tectonic plates move, Alfred Wegener’s ideas concerning continental drift were considered by the scientific community as so much misguided naïveté (to be generous). Only with the final acceptance of a logical (and demonstrable) mechanism for the movement of massive sections of the earth’s crust was the theory finally brought within the realm of “real science.” (see definition #5).
The acceptance of evolution as a scientific “fact” is even more instructive. With the publication of The Origin of the Species in 1859, Darwin proposed a radically new theory (sort of) on how species develop. But it wasn’t until others linked Mendel’s work on heredity with Darwin’s careful observations and hypotheses that the debates ended and evolution became the cornerstone of much of modern science.
And what was true for continental drift and evolution is true of almost all the sciences, from astronomy and archaeology, through classical physics to volcanology and zoology. In the world of science, basic principles are discovered, investigated and expanded upon. But even more importantly, there is a logical, sequential process in which each new discovery is built on a deep knowledge and understanding of what came before. Even when discussing Thomas Kuhn’s idea of paradigm shifts, the “new” scientific paradigm must describe the logical linkages as well as, if not better than, the previous one.
The Nature of Magic: For the purposes of this discussion, let us separate a magician’s parlor tricks from “real magic,” and assume that “real magic,” as described in fantasy novels (Harry Potter, et. al.) , somehow actually works. Not any one set of “magical rules” from any one novel, of course, but the range of what is popularly understood of as “magic.”
In the world of “real magic,” the basic law is that, if I do THIS, then THAT will happen… If I say the correct magic words, in just the right order, with just the right pitch, then some outcome I desire will occur. Or, if I wave my hands in the proper pattern, with the appropriate scowl, then something amazing will appear.
If asked to describe HOW the magic happens, the magician may describe how things below are reflected in things above, or visa-versa. Or he might tell you how a blood sacrifice allows him to pull power from the hidden gods… or she might reluctantly explain how reciting the true names of tree nymphs binds them to her, and gives her their power.
But what you will not hear is a description of how magic works, based on any known physical principles. There will be no logical train of material processes/properties that, when fully articulated, will lead any layman from an understanding of how the mundane world works to one in which “real magic” functions.
The Conflict Between Science and Magic: On the other hand, in science, if we do THIS, and THAT happens… the scientist can (and probably will) give you a step-by-step description of how one physical process or property leads to the next, and how the whole chain of events produces the outcome. And this process can be (for the most part) followed and understood by any reasonably intelligent listener.
Mostly… The one field of study where a logical, sequential explanation of what is happening breaks down is quantum theory (and, okay, maybe cosmology). So, to the question of what is the difference between science and magic? I propose that the most important difference is that, while one can understand THAT magic might work, one must be able to understand HOW something works for it to be considered a “real science.” There is no science I know of where the scientist, in attempting to describe her field of study, says… yeah, well, we have absolutely no idea how it works. It just does, and that’s good enough for me. Again, this is true of all the sciences, other than in the realm of the very, very tiny (and of the very, very big).
As one enters the world of quantum theory, there is a certain point, as one travels down the scale from the macro world to the micro, that the journey slowly turns from the study of science into a discussion of magic. From the macro world of this is HOW and WHY something happens/works to the micro, where it just DOES, and we’re still trying to figure out that whole, pesky HOW and WHY thing.
Describing vs. Explaining: Math does an unparalleled job of describing the quantum world. In fact, it is one of the only ways to deeply explore that environment. But arriving at the formula E = MC2 does not explain why E should be equal to MC2, only that it is. Why is it not equal to the cube of C? Well, because the math leads you to the square, not the cube. When people ask why; ask to have something explained, the answer they are looking for is a description of the basic principles involved, and how those principles lead to the outcome.
In quantum mechanics, the physicist is almost always forced to say “This is what happens. We have proof that this happens. But let me give you my personal belief as to WHY it happens.” The physicist can describe in mind-numbing detail what happens. She can discuss with other physicists the math of what happens. But when required to explain why this thing happens to a non-mathematician, she is thrown back on using metaphors and similes.
So, for the sake of further discussion, let us pull apart the meaning of the word “understand” into two separate components. The first will be UD; understanding that comes from being able to describe a thing or system. The second will be UE: an understanding of a thing or system that allows for explaining how and why it works. Usually, in the macro, mundane world, the two meanings of the word are mutually interdependent. But the more one studies quantum theory (and to some degree cosmology), the more one relies on UD, and abandons UE.
Post Script/Math: Math is not fundamental when trying to help someone understand how evolution works, or when the first humans came to America. It’s not even really necessary when describing the basic principles of bridge building or cathedral erecting (neither the Roman’s nor the medieval French used advanced mathematics). In almost all cases, math is supportive of, but not essential to, an understanding of a scientific or engineering subject.
If one wants to have a truly deep understand of engineering, then yes, math is absolutely necessary. But in those topics normally thought of as “scientific,” math is, at best, the junior partner.
Last Thoughts: There are so many explanations and descriptions of what is or might be going on at the quantum level… pilot waves, standing waves, multiple dimensions (4, 6, 8, 10 or 26), strings instead of points, tunneling, entanglement… the interested lay-person is often left wondering what physicists really know, and whether or not they telling the general public a collection of JUST SO stories. And, in this field at least, the distance between knowing what is happening, and understanding why it is happening continues to be a seemingly unbridgeable gulf. Not forever, certainly, but for now.
Pick up almost any issue of Scientific American or Discover magazine, and you will read articles on the latest discoveries in archaeology, astronomy, meteorology or paleontology, but only descriptions of the latest theories concerning the quantum world.
Summary: Arthur C. Clarke’s Third Law states that “any sufficiently advanced technology is indistinguishable from magic.”
I humbly concur. I believe our understanding of the quantum world will remain more like magic than science until new theories are developed and tested that give one, and only one explanation for why “wavicles” have their dual nature, how electrons can tunnel and if entangled particles are really one thing or two.
Until then, it’s just magic, all the way down.