The Higgs Boson

January 11, 2012

I am beginning to attract some religious conspiracy theorists…I think I’d better change the subject!

So…deep breath.  I’m going to attempt to explain this whole Higgs boson thing which the news keeps going on about, and which, seeing as it is supposedly one of the most important things ever, I’ve been meaning for a while to actually try to properly understand.  Usual disclaimers: I am not a physicist (in fact whether or not I’m even a proper mathematician is arguable) and I am writing this mainly as a motivation to increase my own understanding.  However, my theory is that, unless an expert is a supremely good communicator, it is often easier to gain a basic understanding of a complex subject from another interested layperson (as they know exactly how you feel).  Certainly I would have liked someone else to have written something like this to save me the effort!

I think we have all heard about the search for the Higgs boson by the people at CERN.  Probably, if you’re still reading this, you have also, like me, wondered exactly what this boson is, what it does, and why it matters so much.  And probably you have some vague notion that it is a particle which “gives other particles mass”.  That is the point I shall start from.

But first, a question – why are things the size they are?  Sounds a bit vague and philosophical, I know.  But the size of an object is determined by the size of the molecules which make it up, which are in turn determined by the size of their constituent atoms.  Atoms consist of a nucleus made up of protons and neutrons, surrounded by orbiting electrons.  And the size of an atom is determined by the sizes of the orbits of its electrons.  But the size of electrons’ orbits depends on the mass of the electron!  So in order to find an answer to why things are the size they are, we need to address the question of why an electron has the mass it does.  And while we’re at it, we may as well ask why other elementary particles have the mass they do…for example, why do photons have no mass at all?

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