Faye Flam, the science writer for the Philadelphia Inquirer, happens to own a cat named Higgs (the name was bestowed well before the boson was found). Higgs often takes over the column to explain stuff to readers, and in yesterday’s Inquirer, Higgs explains his eponymous boson, how it was found, and what it means. It’s a good read for those of you who want the basics. The only problem is that, at the end, Higgs doesn’t ask for his nomz, which he usually does at the end of his columns.
I’m still warping my head ’round the Higgs. Perhaps somebody (from Sweeden?) can help me straighten this out?
Here’s my munderstanding:
Start by imagining a magnetic field. Move a piece of iron through it, and the field pulls it this way and that. Do the same with a piece of wood, and it’s as if the magnetic field doesn’t even exist.
A magnetic field can be induced by a flow of electrons, but it’s some sort of quantum exchange of photons that I don’t really understand that causes the forceful interaction.
The Higgs Field, if I’ve got this right, is analagous to an electromagnetic field, except that it’s the exchange of Higgs Bosons rather than photons that does the pushing-around of things. Further, it would seem that the Higgs Field is not polarized as are eleactromagnetic fields. Baryons interact with the Higgs Field for similar reasons that ferrous metals interact with magnetic fields, and photons don’t interact with the Higgs (and thus are massless) in the same way that wood isn’t magnetic.
Would one then expect local variations in the intensity of the Higgs Field? If so, that would seems to suggest that mass is not necessarily constant, which would seem to go against everything I know of physics. But if the Higgs Field is universally uniform, that would seem to make it more akin to the Luminiferous Aether than a particulate field.
Any help at getting me through these hurdles would be appreciated….
b&
Yes, I have also thought that the Higgs field is much like the aether that Michelson & Morley failed to detect in the late 1800s. In consequence of this failure Einstein elevated the non-existence of the aether (an absolute standard for motion) to an axiom of the theory of relativity, with marvelous and bizarre consequences for our understanding of the world. But I wonder if future physics might look back on Einstein’s theory as a brilliant idea ultimately subsumed by some theory (string theory?) that perhaps identifies the Higgs field as the long-sought aether.
The state of modern particle physics these days makes me think of Ptolemy’s model for the solar system with its myriad epicycles; by adding more epicycles one can apparently model the details of planetary orbits as closely as needed. And so it seems to be with modern physics: Something needs explaining? Well let’s just add another particle with esoteric properties.
But I’m an engineer, not a physicist, and though I read about these things I find that attempting to read papers by physicists these days involves a steep learning curve.
One question that I wonder about: Does the Higgs field explain the equality of intertial and gravitational mass?
Well, mass is a mess!
Our mass comes to ~ 99 % of quark-gluon interaction in the nucleons (protons and neutrons).
Nucleons are a bag of quarks and gluons with only three unpaired quarks. Apparently when you measure and simulate carefully you find that only ~ 1 % of the (relativistically) invariant mass is quark mass from the higgs mechanism. (See Strassler’s articles.)
But the higgs mechanism is important because it makes the protons slightly less massive than neutrons, so the stable nucleon. It gives us atoms with a charged nucleus and hence structure formation.
The higgs field may even give us matter/antimatter symmetry breaking, since supersymmetric higgs theories can have many fields. Some universes can prefer matter, other antimatter.
In fact I would prefer to think of the higgs field as less about mass and more about stability. If the 125 -126 GeV Higgs is a standard higgs and there is no new physics prohibiting it, it is also likely to give us a quasistable vacuum. After a long time atoms start to fall apart as the vacuum would do so, ushering in a structure-less universe.
This is akin to how I like to simplify magnetic fields. Classically they can be seen as a low velocity relativistic effect of the electric field.
[Everyday relativistic effects are not unheard of. Gold is a tinted metal, because some of its electrons couple similarly relativistically and modifies the absorption spectra.]
Hence it is easier for me to think of uncharged particles as the exception from electric charge than non-magnetic particles.
The higgs mechanism and dark matter is more analogous to atom theory in predicting structure formation IMHO.
Einstein found that molecules predicted brownian motion in the absence of liquid heat convection. It is analogous to how we detect the higgs field by fundamental particle mass in the absence of other mass mechanisms, or how we may detect dark matter by nucleon recoil in the absence of photon or radioactivity recoil.
I probably tire everyone with this reference, but physics is not a rube Goldberg machine. Physics observably converges on lasting understanding.
Oh, I forgot: does the Higgs field explain the equality of intertial and gravitational mass?
As seen, not generally. It possibly does so for many Standard Model particles. Not massless photons & gluons, not neutrinos, and apparently not the free boson fully. But in many cases there is a linearity between energy and the inertial invariant mass that the higgs mechanism:
“By contrast, only those particles that get their masses from the Higgs field have a relationship between their masses and the strength of their interactions with the Higgs. In particular, as you can see in Figs. 3 and 7, the Higgs particle itself does not get all of its mass from the non-zero Higgs field — and the strength of its interaction with itself is not directly related to its mass. [There is a correlation, but not proportionality.] This is not unusual. In other articles on this site, you will see many other examples of conjectured particles, such as those that arise in the speculative theories known as supersymmetry and as warped extra-dimensions, that get their masses in other ways.
So the link between gravity and energy (and thereby mass, in daily life) is absolute, while the link between the Higgs and mass is likely to be true only for the known elementary particles, and may not be true for other elementary particles yet to be discovered — and is not even true for the Higgs particle itself.
In other words, any resemblance between the Higgs field and gravity is purely coincidental!”
Why the linearity? Well, you may want to study particle physics to get to know that! =D
Uh oh, that can’t be me. I haven’t studied quantum field theory or the standard model. To do solid state physics you can start out simpler.
I’m goint to do a Feynman on magnets to keep this brief. Maybe more later.
Yes, the higgs field, responsible for the higgs mechanism, gives some fundamental particle’s mass by way of virtual particles, shortlived disturbances in the field, in the same way that virtual photons of EM fields causes interactions. (I find Strassler the go-to guy here.)
The higgs field is our first known universal scalar field (since spectroscopically fundamental particles have the same masses the universe over). That is one reason it has been controversial. But it also points to similar physics (cosmological constant/vacuum energy, inflation fields et cetera).
To see why the free Higgs boson, which is one out of a quadruplet in the standard Higgs model, gets its mass, see the link I gave on the linearity (or not) of the resulting effective mass.
In short, the free higgs is not a virtual higgs any more than the photon is a virtual photon. That is why the higgs can be so massive.
Thanks for the link on virtual particles (which, it seems, are neither virtual nor particles). I don’t know that I’d say that I understand the subject better, but I will say that I think I misunderstand it less.
So…would the photon fields and electron fields therefore be as all-pervasive as the Higgs field…?
b&
They would be a part of the vacuum as I understand the plain talk descriptions given on quantum field theory. The vacuum should have all fields even if the value is 0, or rather quantum field “zero point” (not quite 0 due to uncertainty principles).
Then you have charges as sources for the fields that we are more affected for on top of that, and all hell breaks loose. (As in, complicated spherical coordinate solutions to simple problems like the EM field around an electron. Yuck.)
Affected *by*.
Thanks again.
I’m guessing I’ll have to set aside some time in the next year or three to start to come to grips with basic quantum mechanics, at least at an introductory level, presumably including the math. Maybe audit a college course, or at least check out the textbook list from the library.
That’s gonna suck…but how else am I supposed to understand how the universe works?
Ah, well….
b&
Lu Lr – C At. (71 103 6 85).
I was wondering when you were going to say something that made sense. 😀