But Richard Dawkins is indeed a wonderful science communicator. It was his Royal Institution Christmas lectures which gave me – and probably tens of thousands of other children – a real understanding of how something as complex as an eye can evolve. He invented the concept of the ‘meme’: the way that ideas can be selected by evolutionary pressures just as genes can. And it’s his concept of ‘the middle world’ that will be useful to bear in mind as we travel towards the Higgs Boson and particle physics.
The middle world is the human-sized world. It’s the world we evolved in, the world we interact with, the world babies investigate with their endless experiments. We learned, as children, that when we drop things they fall, that a thing can only be in one place at one time, that objects are solid and we mostly cannot mush them together, that feathers fall slowly and spoons fall quickly when we drop them from our high chair. The middle world is the world of useful knowledge, it’s the world in which we live and in which our intuitions serve us very well.
But this world is only a tiny slice of the whole of reality. There are galaxies upon galaxies stretching out to infinity in the big world beyond us. And in the small world within any single object, there are molecules and atoms and particles far smaller than we can imagine.
That is the point: we cannot imagine them. We should not hope to be able to. Our intuitions and imaginations, helpful as they are for working out human size problems like whether our neighbour is likely to cheat on his wife or how far away Geneva is from Inverness, are only useful in the middle world. In the very small world, or the very big one, those intuitions are likely to mislead and confuse us. When we find results that seem to make no sense, we should not be surprised or alarmed. ‘Sense’ only belongs to the middle world.
In the unimaginably small world of fundamental particles, we can say things like ‘this particle is also a wave’ and this is true although it could not conceivably be true of any of the normal-sized objects we encounter in our ordinary lives. We’re going where intuition cannot help us.
So, with that out of the way, what about this Higgs Boson, then?
Here’s the thing: the Higgs Boson is a discovery which, at the moment, makes no practical difference to life in the middle world. Pure investigation for its own sake can often lead to wonderful practical inventions – early experiments in electricity, for example, weren’t undertaken with the invention of the light bulb in mind – but that’s not the reason we go looking. We look because we want to know: because having explored almost the whole fullness of our middle world, we want new frontiers. The vastness of space and the dream that human beings might one day tread on another planet under another sun is the frontier of the bigger-than-us world. And the way that quantum particles interact is the frontier in the smaller-than-us world.
The first thing about it is that, as people in search of the truth about the way the universe operates, we’re not really interested in the Higgs Boson itself – we’re interested in the field whose existence the discovery of the boson makes far more probable. Not that we’ve actually found the boson – we’ve more ‘found a particle which fits the criteria we were looking for in this boson’. In science, results are rarely cut-and-dried. But it’s still exciting news, if we think further than the middle world.
So this Higgs Field. Which Peter Higgs himself would probably rather call a Scalar Field – that being a term for what it does rather than naming it, like a geographic feature, after the first person to find it. Scalar is a helpful word here because of its implication that the field has an effect on the thing it comes into contact with; that’s a good thing to have in mind. The Scalar Field that Higgs theorized is an elegant and beautiful solution to a problem. The problem is: why do some quantum particles have more mass than others? Without something like this Scalar Field, the Standard Model, whose equations describe and predict the nature of the physical world, would have no explanation for why a photon – which makes up light – has no mass, whereas some other particles have a great deal of mass. Peter Higgs suggested that the extra mass could come from the particles interacting with a Scalar Field.
It’s no good. We’re going to have to go back to the middle world for a moment, just to get our bearings. In his book Massive, the Guardian’s science correspondent Ian Sample relates a useful analogy, one which we can understand with our human-scale intuition.
Imagine a field of snow, stretching out as far as you can see. Now imagine that you’re trying to cross that field. There are different ways to cross it. A skier could skim across it on skis, a walker could walk using snowshoes, or a trudger could trudge through in boots, sinking deeply into the field, the snow coming up to their thighs.
The skier is like a particle with no mass – it doesn’t interact with the Scalar Field at all – and it travels very quickly. The snow-shoe walker is like a particle with mass – it interacts with the field and moves more slowly. And the trudger is like a particle with a big mass – it interacts with the field even more and moves very slowly.
The field isn’t made out of snow, it’s made out of these Higgs Bosons, it stretches throughout the universe and the different interactions that different particles have with it determines their mass.
That was the theory, anyway. But until we actually found a Higgs Boson – a particle which had the right characteristics to perform the functions of a particle in this Scalar Field – it was just a hypothesis. And this, cautiously, with a few reservations, is what we seem to have done. Scientists at CERN have smashed together particles at extremely high speeds and have found a boson which looks like it’s the one.
The curious thing about science though, is that although this is ‘good news’, in the sense that we’ve probably found what we thought was going to be there, it’s not like finding something different would have been ‘bad news’. That would be middle world thinking again; man goes looking for the source of the Nile, finds the source of the Nile, yippee. Man goes looking for the source of the Nile, fails to find the source of the Nile, boo. Science isn’t like this.
If we went looking for the Higgs Boson and found something unexpected, that would be just as interesting a piece of news, if not more so, than if we found what we predicted would be there. Like thinking you know what’s going to happen on page 150 of a novel and finding that the novelist has come up with something you could never have expected, surprises in science aren’t bad, just interesting.
It makes a good news story, of course, this moment of wild hurrah, the sense of a completed project and a mission fulfilled. And I suspect it also has something to do with the popular-in-the-media name for the Higgs Boson, that name I’ve been holding off on using throughout this piece because he does, indeed, overshadow everything. There’s no reason to call the Higgs Boson the God Particle. It is, as Rolf Heuer, director of CERN said, ‘the missing cornerstone of particle physics’ and a ‘milestone in our understanding of nature’. It’s great news. It has nothing to do with God, but ‘God Particle found’ makes a good headline.
Why do people call it the God Particle? For this I turn to NPR, which reports: ‘Nobel Prize winner Leon Lederman, who was Fermilab’s director for many years . . . wanted to call [his] book The Goddamn Particle, because nobody could find the thing. However, his editor discouraged him from the title, suggesting that The God Particle would sell many more copies.’
Here we are again, in the middle world, thinking about human irrationalities, and how to influence book sales. Out there, in the infinitesimally small world, we’ve finally found that goddamn particle. But we still don’t understand everything about everything. Onwards.
Photograph by Jim Downing
