In all the recent hoopla about the long-sought Higgs boson, you often hear it said that it is responsible for the mass of the universe. This is not true. Assuming it exists, the Higgs boson is actually responsible for only a small fraction of the total mass of the universe.
This is not to say that the Higgs boson is not important. The main role of the Higgs in the standard model of elementary particles is to provide for the symmetry breaking of the unified electroweak force by giving mass to the weak bosons and splitting the electromagnetic and weak nuclear forces. It also gives mass to the other elementary particles. If elementary particles did not have mass, they would all be moving at the speed of light and never stick together to form stuff like stars, cats, and you and me.
The mass of the universe, however, is not simply the sum of the masses of the elementary particles that constitute matter. Einstein showed that the mass of a body is equal to its rest energy. If that body is not elementary but composed of parts, then its rest energy as a whole will be the sum of all the energies of its parts. This sum will include the kinetic and potential energies of the parts in addition to their individual rest energies.
Now, for the bodies of normal experience, such as your neighbor's cat, the kinetic and potential energies of their parts are small compared to their rest energies. So, so for all practical purposes, the total mass of a cat is equal to the sum of the masses of its parts.
This is even true at the microscopic scale. The masses of chemical elements are, typically, thousands of MeV (million electron volts, in energy units), while the kinetic and binding energies are a few tens of electron volts. Only when you get down to the nuclei of the chemical elements do you get kinetic and potential energies that are measurable fractions of their rest energies.
Inside nuclei, we have nucleons--protons and neutrons--that are themselves composed of quarks. Since quarks do not appear as free particles outside nucleons, their masses must be estimated from studying the effects of their mutual interactions on the masses and other properties of nucleons and other particles that are composed of quarks. Fortunately, there are only six quarks but hundreds of particles made from these quarks to provide data to pin down quark properties. By using supercomputers, physicists have obtained reliable estimates of quark masses. The result: the masses of the quarks inside a proton or neutron constitute only 1 percent of its mass.
The objects familiar to most humans, including most scientists, have masses that are essentially given by the number of protons and neutrons they contain. So, we can say that only 1 percent of that mass arises from the masses of quarks. Furthermore, this normal stuff is itself only 5 percent of the total mass of the universe.
Now, where does that leave Mister Higgs? While the Higgs mechanism gives masses to elementary particles, other processes may contribute to the masses of quarks. I need not get into these. Even if all the mass of a quark comes from the Higgs mechanism, the Higgs contribution to the mass of the universe is less than one part in 2,000.
I don't like the standard model much, either. It describes, but it doesn't give any hints to what the real physics is. And what's worse, the next possible extension, SUSY, is even worse. More particles, more free parameters, little indication what's really going on.
Having said that, nature deals the cards. You play the hand that she gives you. And right now... she has given us the standard model and little hints that it's a sucker bet, but no idea which hand we should be really playing.
We can't teach the theory, of course, that's much too hard on the high school level, but we can show examples of systems that undergo these processes behave.
If we can give students a feeling for how simple classical systems can undergo these transitions and organize themselves into complex phases, then we can hope that these students will, at least on an emotional level, be able to understand that the kind of research physicists do on the vacuum is in many ways very similar to what they have seen in the classroom.
You remember those three, don't you?
Course I could be thinking of the Schmiggs particle the Aussie commenter mentioned below. (lol)
http://philsci-archive.pitt.edu/4073/1/higgs.pdf
If I understand him correctly, he basically says that the mathematical nature of the Higgs mechanism doesn't provide any understanding, at all, even if the Higgs exists, which, he admits in his paper may very well be the case!
I happen to agree with him, even though I am still struggling with the finer technical points of his argument. I think the Higgs is a consequence of the structure of the standard model and it basically has to be there if the standard model is anything but one big fluke of nature. But you can make the very same argument for the photon, the gluons and the Z and Ws, the Higgs just takes it one level further.
The real question for a physicist is:
"What's the actual structure of the real vacuum for which the standard model is such a good sub-TeV approximation?"
And sadly, the LHC discovery can not answer that. It can prove, within some limits, that the standard model is a good approximation, but it sheds no light on the underlying physics, at all.
:-)
:-)
Aren't you, Scott?
:-)
I trust you're not one of those "God is great...Kaboom!" charmers. Come on - disappoint me!
M.
Then what's the point of the article?
And he is absolutely correct about that.
The sight of an obvious question has been lost in all this recent excitement - what endows the
Higgs particle ITSELF with mass?
Do we need spend a further $10 billion to look for the Shmiggs particle - a "Super-God" particle theoretically indispensable to giving the Higgs its all-important mass?
Hey, how about another $20 billion to look for the "Sucker born every day" particle without which
the Shmiggs couldn't have mass either...
And so on and on... the stomach turns.
Mark Gendala
Melbourne, Australia
www.ssotu.com
Spontaneous symmetry breaking.
"Do we need spend a further $10 billion"
Estimates for the next facility are closer to $20 billion.
"And so on and on... the stomach turns."
About some people's intellectual limitations. Absolutely.
I am not sure what your problem is, anyway. Australia's contribution to the LHC is minute.
It depends on how much of the mass of dark matter comes from the Higgs mechanism. Even if dark matter also only gets 1% of its mass from the Higgs mechanism then the Higgs contribution to the mass of the universe is more than one part in 400.
Now, as for dark matter... one possible dark matter candidate is the lightest supersymmetric particle. So far, no signs of supersymmetry have been found at LHC, although it's too early to rule it out within the full energy range of the machine completely.
If you look at the LHC design proposal, you will learn that SUSY searches are part of why the machine has been built. If LHC does not find SUSY within its energy range, some of the theoretical advantages that a supersymmetric extension of the standard model offer are, sadly, going out the window, though. That does not mean, of course, that there is no SUSY, at all. It merely means that the energy gap to the lightest superpartners is too large to be detectable at LHC energies, if SUSY is the correct next step, after all.
It doesn't yet reveal whether there are more Higgs, anything about post-standard model physics, and doesn't provide any insight into gravity.
However, the Higgs mechanism does a most excellent job of explaining the mass of even a highly-relativistic cat.
:-)
:-)
It may not be so easy, because mathematical consistency of Higgs mathematics in our cherished four dimensional universe is an open problem.
But go ahead.
We've got a lot of space here, waiting for ya.
I didn't say that they have. Did I? I just used an arbitrate term of importance to demonstrate that the person has no clue about any of this.
"It may not be so easy, because mathematical consistency of Higgs mathematics in our cherished four dimensional universe is an open problem."
What is "Higgs mathematics"?
:-)
"We've got a lot of space here, waiting for ya."
I am here... but I have absolutely no clue what you are talking about. Do you?