http://www.bbc.co.uk/news/world-18702455
But what does all this actually mean? Can someone explain foir a layman why this is so important?
Probably very little. Then again, the neutron was discovered in 1920, and 25 years later, Hiroshima went up in flames, so who knows?
My limited understanding:
The Higgs field is what gives mass to material objects. Imagine walking through an open field compared with walking through a field covered in 6 foot deep snow, the field with snow offers considerable resistance to motion, which is analogous to inertia. This theory up until now has been conjecture. With the discovery of the Higgs boson (the particle associated with the Higgs field the same way photons are associated with EM fields), that theory has been proven.
I believe scientists have made plenty of theoretical headway by assuming that the Higgs theory is true. So the confirmation of the theory simply confirms what was already deduced. So, while exciting, this discovery is not nearly as exciting as if the Higgs particle was conclusively ruled out. THAT would have ushered in a new era in physics similar to the Michelson-Morley experiment which ruled out the luminiferous ether.
I’m not a physicist or anything close. So hopefully that will tide you over until the people who really know what they are talking about show up.
The reason the Higgs discovery is such a big deal is because it indicates, in a big way, that physicists really are “on the right track” and aren’t just theorizing in a vacuum.
The existence of the Higgs boson is required for the Higgs field theory to work, so its NON-existence would require rethinking a whole mess o’ physics. On the other hand, finding a particle with the expected properties of the Higgs boson purely by chance would be extremely unlikely, expecially since (as I understand it) the Higgs boson was predicted with some rather odd, specific properties.
So the fact that they seem to have detected a particle with the right characteristics adds a ton of validation to working theories, and it’s an example of a real predictive “test case” for a theory that explains a lot about the lowest, most basic levels of physics.
I think DrCube says it well. I’d add there were different ways posited for the Higgs field to impart mass (Higgs “mechanisms”), and so the discovery validates that it works by ways of the simplest mechanism that was theorized.
Here’s a readable and informative FAQ: The Old Higgs FAQ – Of Particular Significance
It’s extremely important in the world of particle physics, and so should be important to anyone who cares about expanding humankind’s understanding of the fundamental workings of the universe. As for practical-application type importance, we probably won’t know if it has any for another century or so. But 19th century physicists studying electromagnetism didn’t know it’d lead to the Straight Dope Message Board, either. So who knows?
As for why it’s important in a particle physics context:
- It’s the last missing piece of the Standard Model, making it not only an important verification of theory but also the crowning achievement in a scientific endeavor that has involved decades of research by thousands of scientists.
- It is evidence of the Higgs field, which is believed to give mass to the other fundamental particles. (However most of the mass of you and me comes from the strong interactions holding our protons and neutrons together, not from the Higgs mechanism)
- It has various properties that make it unique among fundamental particles. It’s spinless, chargeless, colorless, odorless, tasteless, dissolves instantly in liquid, and is among the more deadly poisons known to man.
- Because it interacts with anything that gets its mass through the Higgs mechanism, it could lead to evidence of new, undiscovered particles beyond the Standard Model.
Regarding this last point: There are various reasons, both theoretical and empirical, to expect that the Standard Model is only a very good low-energy approximation to the true fundamental theory. “Low energy” in this case means “up to the level we’ve been able to probe with our accelerators so far”, but that will hopefully be changing as the LHC continues to gather more data.
Well, close to it, anyway. We don’t yet know for sure if it’s exactly the Standard Model Higgs, but it’s at least something that looks a lot like the Standard Model Higgs. At this point the measurement is consistent with the SM Higgs, but with more data it may prove to be a little bit different.
A non-SM Higgs is actually the preferred option I think for most physicists, because it will help point the way to what lies beyond the Standard Model.
There are also some theories (notably, Supersymmetry) that predict multiple Higgs bosons, of which this might just be the lightest one.
Can you clarify what you mean that we get most of our mass from the strong interaction? (I assumed we got it from the constituent of our atoms, which in turn get it from the Higgs mechanism.)
And if mass comes from the Higgs field, what happens when you throw a baseball through a window–i.e., where is the force coming from that breaks the window? (Is that somehow the Higgs field in action, acting on the window? Or is the electromagnetic force, essentially)
I find it difficult to keep these quantumn fields grounded in our everyday reality…
We do get our mass from our atoms, and those atoms are made of protons, neutrons, and electrons. And the protons and neutrons are each made of three quarks (well, to first approximation; there’s a lot of stuff going on in there). And it’s true that quarks and electrons get their mass from the Higgs mechanism. But the mass of a proton is much greater than the mass of three separate quarks.
How can this be? Well, mass is essentially a measure of how much energy a thing contains. This can be from the mass of its constituents or the energy binding those constituents together. If you put two 1 kg bricks next to each other, the total mass will be 2 kg, and whatever forces exist between the bricks will be so small by comparison as to be irrelevant. But if you put two quarks next to each other, it’s a different story. There the binding energy becomes the dominant contributor.
It’s essentially the electromagnetic repulsion between the atoms of the glass and the atoms of the window. It’s true that the fact that this force causes the window to break rather than the ball to bounce off is related to the mass of the ball (if it were less massive, it’d be easier to deflect). But the origin of that mass is, like I said, mostly in the strong interaction, not the Higgs mechanism.
Tim:
Thanks, that’s rather fascinating. So, energy is sort of a free-form concept–i.e., it’s not a measure of a field’s strength acting on an object, but a property of the object itself, independent of interactions with the Higgs or Electromagnetic fields (?)
Exit question, I never fully understood some aspects of quantumn fields before now–so am I correct in understanding that the Higgs Field is unique in that it has a non-zero value? (Or is that only the case locally near a particle?) And, in contrast, the electromagnetic field has a zero value?
How soon before hucksters are selling “Higgs Field Inhibitor” bracelets, promising to help people lose weight?
We are not going to fight about this.
Take your genuine question with factual answers to General Questions where it belongs. 
Strong force? Higgs field? Nonsense! It’s all witchcraft I say!
So you’re saying the OP made a massive blunder?
There will be lawsuits, demanding that the CERN folks provide everybody with these, at CERN’s expense. All the people who feared that the LHC would destroy the world, or civilization, in one way or another, were right. All the Higgs Bosons they’ve created have pervaded the planet over the past few years, and are the root cause of the epidemic of obesity we’ve been seeing.
ETA: At least, we now know that God is particulate, with a half-life in the low billionths of a second.
Energy is a property that things have. Fields can have energy, particles have energy (although in quantum field theory particles are really “excitations of fields”), particles interacting with fields can have energy.
But it wouldn’t be correct to think that the energy of a thing is just a measure of how strongly it interacts with the Higgs field. That’s just one kind of energy. Even for fundamental particles, there’s also kinetic energy, which isn’t due to the Higgs field.
If you now understand all aspects of QFT you’re doing better than me 
The Higgs has a non-zero “vacuum expectation value” (vev for short), meaning it’s non-zero even in the absence of other stuff. This is in contrast to electromagnetic fields, which would be zero in the absence of charges.
The Higgs gets its vev from spontaneous symmetry breaking (roughly, the symmetric case of zero Higgs field is less stable then the asymmetric case of non-zero Higgs field). I know of other physical systems that undergo a form of spontaneous symmetry breaking (e.g., superconductors), but I think the Higgs field might be the only known case of it happening in a vacuum.
“Higgs Field Inhibitor”? Wasn’t that what did in Dr Jonathan Osterman? 
Well, maybe to cure his higgups.
He got better.