Shortly after the existence of the Higgs boson was quasi-confirmed, I wrote a short post noting, among other things, that I don't really understand what a Higgs boson is. This upset such commenters as Brad Watts, who wrote, "If you have no idea what the subject is about, then you shouldn't be writing about it."
Happily, the commenter known as ugluk2 (apparently 'ugluk1' was already taken) leapt to my defense:
Wright actually gave the standard explanation that is handed to us laymen when physicists or science writers try to explain what the Higgs boson is. Wright just had the honesty to admit he doesn't really understand it and speculates that physicists themselves only understand it on a mathematical level. Which is more or less what Richard Feynman said about quantum mechanics.
Exactly , ugluk2. Feynman (who won the Nobel Prize for his work in quantum physics) made that point in his great little book The Character of Physical Law. And if I recall correctly, he literally said that nobody--including him--really understands quantum physics. Because once you get very far down into the subatomic world, the reality implied by the math just isn't amenable to intuitive comprehension. Which was exactly and explicitly the point of my post.
My Atlantic colleague Garance Franke-Ruta, undaunted by the likes of me and Feynmann, has heroically assembled a state-of-the art layperson's description of what the Higgs boson is. When I saw the headline--"Still Confused About the Higgs Boson? Read This"--I was seized by alarm. I figured that if I read her piece and was no longer confused, I would have to retract my profession of ignorance and abashedly concede comprehension. It is with relief and delight that I now report that I have read her piece and still don't get it.
I mean, sure, I understand the words, sentence by sentence--just as I understood the words, sentence by sentence, that Feynman himself used to describe quantum physics. But, as Feynman emphasized, sometimes the nature of a physical phenomenon makes it impossible for words to leave you with a clear and coherent picture in mind.
For example, Garance writes that bosons are a special kind of particle: two of them can inhabit the same space at the same time. Now, that by itself just doesn't make intuitive sense. We don't think of two rocks as being able to inhabit the same space--or two pebbles or two grains of sand. Garance acknowledges the problem and suggests we think of bosons not as particles but as "entities". Sorry--doesn't help. To the extent that I can envision something as generic as an "entity" at all, I think of it as a "thing"--and in my intuitive universe two "things" can't inhabit the same space.
Garance anticipates my difficulty. She writes, "Bosons have the capacity to share space because they are more like a force than a thing in the way we normally think of 'things' or 'particles.' "
But if bosons are more like forces than like particles, why do physicists keep telling us they're particles? Maybe it's because for some purposes it makes sense to think of them as particles and for some purposes it doesn't? But that would sound hauntingly like one of the things that led Richard Feynman to say nobody understands quantum physics: electrons are for some purposes best thought of as particles and for some purposes best thought as waves, and if you ask which they really are, the answer isn't one or the other, because in the quantum world things don't have to be one thing or the other, as they would in the macroscopic, intuitively comprehensible world, the world inhabited by rocks and trees and governed by the reassuringly intuitive laws of Newtonian mechanics.
And let's don't forget the main point about the Higgs boson: it is said to be the reason other particles weigh anything at all; it is the particle that "imparts mass to other particles." Now, right there you have something that's, um, a little challenging to imagine. And it doesn't help me much if you say instead, as some people do, that it's the Higgs field that gives mass to particles, because then I have to puzzle over the relationship between the field and the particle. Garance writes:
The Higgs boson is a sub-atomic particle that acts as the intermediary between the Higgs field and other particles... This interaction between the field, the boson and other particles is the Higgs mechanism. The precise nature of the mechanism is still being worked out, but it is through its complex interplay of fields and bosons (Higgs and non-Higgs) that particles acquire mass.
Maybe when this mechanism gets "worked out," it will all make sense to me. But I'm guessing that it will continue to resist comprehension--except in the sense that to comprehend the mathematics of a physical theory is to comprehend the phenomenon being described. As I put it in my previous post, the physicists who may be said to "understand" the Higgs boson are people who "have dropped the idea that to truly understand something is to have a crystal-clear metaphor in your mind, a metaphor that doesn't break down at any point and doesn't contain internal contradictions."
I want to stress that Garance's exposition is, so far as I know, without deficiencies. It's not her fault that sub-atomic reality is so strange. I also want to stress that she's doing great work in seeing how close words can come to conveying the strange inner workings of the world.
And, finally, I want to stress that I'm not complaining about this strangeness. I think it's great that the mathematical principles governing the inner workings of the world, though themselves intelligible to the human mind, suggest a reality that, strictly speaking, isn't. Makes life more interesting.