I love Edinburgh, right from the moment the train pulls in at Waverley Station. I love the fact that it has a daffodil-filled valley with a railway in the middle, where most cities would have a river.

These daffodils are massive.

I visited to take part in a discussion on "Engineering the Large Hadron Collider", chaired by Robin Ince and with a talk from Lyn Evans (who was the project leader for LHC construction). My job was to be on at the beginning to try and explain why we built it. This is of course to do with finding the Higgs boson, or as I prefer to put it, understanding electroweak symmetry breaking (see below).

Peter Higgs is a Professor at Edinburgh University, and members of the physics department there also work on ATLAS, so this was a bit like bringing coals to Newcastle. In fact the Edinburgh group are running a drop-in Hunting the Higgs event as part of the festival.

On Sunday I chaired a talk with Ian Sample on his book "Massive", which is about hunting the Higgs. So I was feeling quite Higgsed up. I now feel like taking this hypothetical boson (not the Prof) down a peg or two. So here are three humbling Higgs facts:

Fact One: Hunting the Higgs isn't why we built the LHC. Actually we want to understand why two fundamental forces - the electromagnetic force and the weak nuclear force - have the same strength at high energies, whilst being very different at everyday energies.

We know this is because of the masses of the particles which carry the forces, and in our "Standard Model" it's the Higgs field which introduces these masses and breaks the symmetry between them. So if that's what happens in nature, we'll find the Higgs. But mainly we want to do physics for the first time at energies above this "electroweak symmetry breaking". Then we can hopefully see how it happens, Higgs or no Higgs.

Fact Two: As Ian pointed out, the Higgs is only responsible for about 1% of the mass of everyday stuff. The rest comes from the binding energy of the strong nuclear force. So there.

Fact Three: Finally, one audience question after Ian's talk was along the lines of

If it is so important, ubiquitous and fundamental, why is the Higgs so hard to find?

This is a really good question. The answer is that in a sense it's not the boson which matters. It is the Higgs field which fills the universe, giving mass to everything etc etc, and that is the really important thing. If you 'believe' in the Higgs mechanism, then every time you measure the mass of something you are seeing evidence for it. On the other hand, this becomes simply a matter of of interpretation, since the Higgs theory has explained the mass, but has made no unique prediction for any new phenomena which you can test experimentally. Maybe some other theory could also explain the mass. In fact this is apparently why Peter Higgs' original paper draft was rejected by the journal. He then went and added something along the lines of

Well, if this field is there, you can also make waves in it and this will appear as a new particle.

THAT is the famous boson and THAT is why we have to see if it is there or not.

Damn, that's sort of made it sound all important again. Oh well.