Theoretical physicists love beautiful theories that unify things. Newton recognized that the fall of an apple was related to ocean tides and the orbits of the planets – these were different aspects of a single phenomenon, gravity. Maxwell unified electricity, magnetism and light. Each synthesis extends our understanding and leads eventually to new applications that change the world.

In the 1960s, there was a renaissance of quantum theory. We started with an amazingly accurate theory of electromagnetic forces, aka quantum electrodynamics. In it, electromagnetic forces are seen as due to the exchange between electrically charged particles of photons, packets (or quanta) of electromagnetic waves. The "weak" forces, involved in radioactivity and in the Sun's power generation, are in many ways very similar, save for being much weaker and restricted in range.

A beautiful unified theory of weak and electromagnetic forces was proposed in 1967 by Steven Weinberg and Abdus Salam – two physicists working independently came up with the same new theory. The weak forces are due to the exchange of W and Z particles. Their short range, and apparent weakness at ordinary ranges, is because, unlike the photon, the W and Z are, by our standards, very massive particles, 100 times heavier than a hydrogen atom. The "electro-weak" theory has been convincingly verified, in particular by the discovery of the W and Z at the CERN accelerator in 1983, and by many tests of the properties. However, the origin of their masses remains mysterious.

The next step is to figure out how mass is created. Anyway, elementary particles have wave properties akin to those ripples on the surface of a pond which has been disturbed; indeed, only when the ripples travel as a well defined group is it sensible to speak of a particle at all. In quantum language the analogue of the water surface which carries the waves is called a field. Each type of particle has its own corresponding field.

The Higgs field is a particularly simple one - it has the same properties viewed from every direction, and in some respects in indistinguishable from empty space. Thus physicists conceive of the Higgs field being "switched on", pervading all of space and endowing it with "grain" like that of a plank of wood. The direction of the grain is undetectable, and only becomes important once the Higgs' interactions with other particles are taken into account. For instance, particles call vector bosons can travel with the grain, in which case they move easily for large distances and may be observed as photons - that is, particles of light that we can see or record using a camera; or against, in which case their effective range is much shorter, and we call them W or Z particles. These play a central role in the physics of nuclear reactions, such as those occurring in the core of the sun.

The Higgs field enables us to view these apparently unrelated phenomenon as two sides of the same coin. When particles of matter such as electrons or quarks travel through the grain or “against the current”, they are forced to move more slowly than their natural speed, which is that of light – or, in another way of thinking, making them heavy. Thus, the Higgs field could be the mechanism that gives particles their heaviness, or mass.

However, like most analogies to make things understandable, the wood-grain one is persuasive but flawed: we should think of the grain as not defining a direction in everyday three-dimensional space, but rather in some abstract internal space populated by various kinds of vector bosons, electrons and quarks.

And that’s the Higgs boson… the process used by reality to make something rather than nothing. This is a completely new form of matter about whose nature we still have only vague hints and speculations and its discovery is the most exciting prospect in arena of contemporary particle physics.