What “The God Particle” Hath Wrought

You’ve doubtless heard the joke: We can’t call the Higgs boson the “God Particle” any more, because now we have tangible evidence that it exists.

But the label “God Particle,” attached to the poor unsuspecting Higgs boson by Leon Lederman and Dick Teresi, continues to wreak havoc on physicists’ attempts to clearly explain what is going on. Last week’s announcements from CERN that the new particle discovered last July is looking more and more like the Higgs predicted by the Standard Model generated stories like this one, from CBS news:

The Higgs boson is often called “the God particle” because it’s said to be what caused the “Big Bang” that created our universe many years ago. The nickname caught on so quickly (even though scientists and clergy alike do not care for it) partly because it’s a great explanation of what it’s supposed to do — the Higgs boson is what joins everything and gives it matter.

That might be the worst paragraph I’ve ever read about the Higgs boson, and I’ve read quite a few. (H/t Faye Flam.) Originally I thought the journalist was just making things up, but it turns out that it’s Michio Kaku’s fault. (H/t Matt Strassler on Facebook.) There is a video linked to the article, in which Kaku says that the Higgs helped cause the Big Bang, and that’s why it’s called the God Particle. Another example where it would have been tempting to rag on sloppy popular journalism, where actually it’s a supposed scientist who is largely to blame. (Although the above paragraph is also wrong about things it should be easy to get right.)

For the record, the Higgs had nothing whatsoever to do with causing the Big Bang. (Kaku tries to link it to inflation, but they’re not related.) It also doesn’t “join everything,” whatever that means. It does give mass to elementary particles like electrons and quarks, which isn’t the same as giving “matter” (since that kind of doesn’t make any sense), and besides which it doesn’t give mass to protons and neutrons and therefore most of the mass in ordinary objects.

The “God Particle” label, despite being very catchy and therefore leading to more publicity than most elementary particles manage to muster, has done more harm than good for the public understanding of science. Non-experts, hearing that physicists have named something after God, might actually think they were being serious. Imagine that.

[Update: Matt Strassler adds his take.]

It’s not going away any time soon. Leon Lederman and Chris Hill have a sequel to the original book coming out, Beyond the God Particle, due later this year. I’m sure the book will be great at explaining the physics, and I’m equally sure the title will generate a lot more confusion. Get your disclaimers ready!

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95 Responses to What “The God Particle” Hath Wrought

  1. Russ Abbott says:

    Would you explain what it means to say that the Higgs gives mass to elementary particles like electrons and quarks but not to protons and neutrons. What mass do protons and neutrons have that aren’t due to the mass of quarks?


  2. Cameron says:

    What does give the proton mass?

  3. Sean Carroll says:

    You guys know that I did write a book about this, right? :)

    The proton gets mass from the strong nuclear force — the gluons holding the quarks together, not from the quarks themselves. Adding up the mass of the quarks inside a proton would get you only about one percent of the proton mass.

    Admittedly, it’s a very tricky thing. One quark by itself would have so many gluons around it that it would have infinite mass. That’s one way of saying that quarks are “confined,” we don’t see them by themselves. Bringing three quarks together in the right way lowers the total mass from infinity to the actual mass we see; but that mass is still much larger than the masses of the individual quarks in an imaginary world where there weren’t any gluons at all.

  4. reydv says:

    I can understand Leon Lederman passing the blame once to his publishers for the title. But twice?. He’s just as guilty for “god particle” mess as any publisher is.


  5. X X says:

    So what gives the individual quarks in an imaginary world by themselves mass?

  6. Sean Carroll says:

    Um, the Higgs? No reason to remove that just because we remove gluons.

  7. John Conway says:

    Sean! you are missing a golden teaching moment here…

    The reason a proton has mass is utterly fantastic: the quarks that make it up, bound together by the gluonic forces that won’t let them out, nevertheless have such a high velocity that they acquire mass via relativity. We all know E = mc^2, but that’s not quite right: it’s E = gamma mc^2 where gamma is a measure of how relativistic a particle is because it’s moving so close to the speed of light.

    That’s right: every proton (and neutron) in the atoms of your body has the mass that it does because the quarks inside it are whirling around at relativistic speeds. It’s really mind blowing…

  8. Bo says:

    So, Higgs gives elementary particles mass and thereby inertia. The Higgs does not give gluons its mass.

    So, where do the gluons get their mass from, and do they have inertia? I’m confused.

  9. Sean Carroll says:

    John, I don’t think that’s really true and/or helpful. It is true that the quarks move rapidly, at least to the extent that “the velocity of a quark inside a proton” can be defined. But it’s not where most of the proton mass ultimately comes from. (If it were, neutrons would naively be much heavier than protons, since the down quark is heavier than the up.)

    The truth, alas, is messy (as you know, probably better than I do). There’s a lot going on inside the proton — many more virtual quarks and gluons than the three valence quarks. I think it’s best to be accurate if not completely precise, and attribute the proton mass at the end of the day to the residual energy of the strong force (which technically includes both the gluons and the virtual quarks).

  10. Bill Brett says:

    CBS is a joke. If you don’t understand that, then ‘god be with you’.

  11. James says:

    Michio Kaku says something wildly overhyped and misleading? Well I never….

  12. Chris says:

    I have to go take a shower after reading that paragraph. I feel so dirty.

  13. Travis says:

    “If it were, neutrons would naively be much heavier than protons, since the down quark is heavier than the up.”

    Would it be almost correct, though, to say that the mass is due to the kinetic energy of the quarks, and the quarks get their kinetic energy from being pulled in so tight by the strong force, just like meteors get their kinetic energy from being pulled in by gravity? The down quark is heavier than the up, but it wouldn’t move as fast when acted on by the strong force because the strong force is not proportional to mass.

  14. vmarko says:


    Gluons are massless, like the photon. Furthermore, “inertia” is only a descriptive idea, not a proper physical quantity, so you are better off without ever referring to it. :-) Rather, talk just about mass (i.e. the “rest-mass”) and energy, without introducing “inertia”. Gluons have energy (kinetic and potential) and have zero mass. Quarks also have energy (kinetic and potential) and acquire some small nonzero mass, due to the interaction with the Higgs.

    When you make up a proton or a neutron, its total mass is determined by its total energy and the equation E=mc^2. And the total energy of a proton is a sum of the rest-energies of three quarks (i.e. the Higgs-generated masses), kinetic energies of quarks and all gluons inside, and potential energies of quark-gluon and gluon-gluon interactions. When you sum up all those energies, you get a result that is very different from the sum of just the three quark masses, since the potential energy of the strong interaction is… well… strong. :-)

    The problem here is that the total energy is actually negative, since the proton is a bound state. And then something called “renormalization” steps in, all hell breaks loose, and after the dust settles, you should end up with a total energy that is positive, and in addition much bigger than the initial masses of the three quarks. That should provide for the total mass of the proton.

    I am saying “should” here, because nobody has actually managed to perform that calculation, not even numerically (despite some valiant attempts). We don’t know how to calculate QCD-anything in the infrared regime. People have managed to calculate the “mass renormalization” (as it is called) in some much simpler toy-example models, and this suggests that something similar is probably happening also in full QCD. But there is no proof yet. One of the Millenium prizes is still waiting for someone to at least prove that a solution exists. 😉

    HTH, :-)

  15. David Yerle says:

    Wasn’t it supposed to be called the “goddamn” particle because it was so damn hard to find? That made a lot more sense than the alternative…

  16. James Gallagher says:

    Hi vmarko,

    Some calculations have been performed, and they have been done to pretty good accuracy, are you dismissing this work?

    Popular reference, but it names the academics involved:


  17. vmarko says:

    No, I’m not dismissing that work — I noted that there are some valiant attempts. But the issue is that in all calculations of proton mass that I have seen so far (though I probably haven’t seen them all), the only thing that is being calculated is the ratio of the proton mass and some other hadron mass, the latter being taken as experimental input. While a 2% accuracy is a great achievement, it still falls short of an “ab initio” prediction of the proton mass — calculated from nothing else but Standard Model coupling constants and the Higgs mass.

    As soon as your input contains some experimentally determined hadron mass, you are taking a shortcut and effectively cheating the ab initio calculation. Even those shortcut calculations are formidable (and deserve every respect!), so I doubt that a true ab initio calculation will be possible in the forseeable future. But people should keep trying. :-)

    Best, :-)

  18. Sean – I am a little puzzled at your criticism of John Conway’s comment. The mass of the proton is a complicated combination of things, but certainly a major component is indeed the kinetic energies of the relativistic quarks, gluons and anti-quarks inside. Of course there is also binding energy and that is equally important. But when you say “it’s not where most of the proton mass ultimately comes from”, I don’t follow your logic. I would say it’s certainly a substantial contribution.

    I am also puzzled by your remark that the neutron would end up much heavier than the proton if John were right. I don’t see why. The difference between the proton and neutron involves the exchange of a single up quark for a single down quark, a tiny fraction of all the particles inside. For two relativistic particles with large energy E and different small masses m_1 and m_2, the difference in their energies is (m_1-m_2)^2/2E, a small number, not a large one. Meanwhile, to show that the difference between the neutron and proton mass is pretty much the difference between the down and up quark masses (with a bit given back because of the proton’s charge) doesn’t require any assumptions about the internal dynamics of the proton or neutron; it mostly follows from symmetry-breaking considerations. So you can’t determine anything about the internal dynamics of protons and neutrons from the neutron-proton mass difference.

    Anyway, while John’s remark could be refined somewhat, I don’t think it’s as fundamentally misleading or wrong as you suggested.

  19. Marko – your statement “The problem here is that the total energy is actually negative, since the proton is a bound state” regarding the proton mass isn’t right. The energy between quarks does not go to zero at infinite distance (since quarks are confined) and so the binding energy is not negative. Consider as a toy model (not the real thing by any means) two particles bound by a potential V(r) = -e^2/r + C r. The bound states do not all have negative binding energy, and indeed if C is large compared to e^2 they may all have positive binding energy.

  20. vmarko says:


    Yes, you’re right, my fingers were faster than my brain, sorry… :-) What I wanted to say was that quarks do not have enough kinetic energy to get out of the potential well. And since the well is infinitely tall (as your toy example illustrates), they are always confined to a bound state.

    But the main point of my post was that the calculation of the proton mass straight from the SM parameters is still not there, and that this is a hard problem.

    Best, :-)

  21. Navneeth says:

    Has the quark-mass-through-Higgs idea been firmly established (as firmly as things can be in QFT)? I understand that mass mechanism was initially proposed to explain the electroweak interaction alone.

  22. OMF says:

    I hereby propose that the Higgs Boson henceforth be known as the “Grand OlD Particle”, the G.O.D. Particle.

  23. Crapbag says:

    Matt Strassler said: “The mass of the proton is a complicated combination of things, but certainly a major component is indeed the kinetic energies of the relativistic quarks, gluons and anti-quarks inside.”

    Eh? Haven’t we been trying to kill the concept of “relativistic mass” for decades now? The mass of a system of particles is not usually the sum of the masses of the particles, but that is *not* because “kinetic energy contributes to the mass”!

  24. kyurkewicz says:

    I’m no fan of God Particle (nor that Kaku interview), but without it we wouldn’t have had this absolute gem of a headline:

    “Move Over New Pope, Here Comes The God Particle”


  25. Kyle Cranmer says:

    I tried to figure out what he might be thinking to justify to himself what he said. My guess is that a few times he said the Higgs “belongs to a family of particles” and at the end he mentioned the inflaton. So maybe he was thinking, “scalar field” and then justified equating the Higgs and the inflaton since they are both scalar fields. My guess is that is how he would reply if pressed.