ANYONE who has been following the goings on at CERN over the past couple of weeks will have heard that mass, the defining feature of “things” in the world, owes its existence to a particle called the Higgs boson, which has come to be known as the God particle. (Leon Lederman, who is credited with coining the term, apparently called it “that goddamned particle”, but with a mix of embarrassment and advertising nous, his publishers shortened it to “God particle”.)
After reading Frank Wilczek’s , however, it is clear that the Higgs god is a laissez-faire deity at best, accountable for only some of the mass we observe – that of elementary particles such as quarks – but leaving the rest to other mysterious forces. The masses of protons and neutrons, for example, are far heavier than the sum of their elementary parts.
So if the Higgs boson is not responsible for most of the mass around us, what is? The answer, Wilczek tells us, is empty space. Only it is not so empty – it is actually seething with activity. In a modern twist on the old concept of “ether”, Wilczek calls this non-empty emptiness the Grid.
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The Grid is reality’s substrate, built from a host of ingredients: quantum commotion; the metric field that delineates space, time and gravity; exotic materials like the quark-antiquark condensate and the Higgs field that together transform empty space into a multilayered, multicoloured superconductor; and the mysterious dark energy that is driving the universe’s expansion.
who, along with H. David Politzer and David Gross, won the , the theory that describes how fundamental particles called quarks and gluons interact to form the protons and neutrons at the heart of every atom. Such credentials give him licence to be wonderfully irreverent. My favourite example is when he describes Einstein’s blockbuster equation E = mc2 as “a little cheesy” because, despite its fame, it only applies to very limited situations. Wilczek is more interested in the permutation m = E/c2, which highlights how mass derives from pure energy.
The ingredient of the Grid that Wilczek finds most intriguing is the quark-antiquark condensate. It sounds complicated, and it is, but Wilczek offers an enlightening explanation. The abridged version goes something like this: truly empty space is unstable. From nothingness, quark-antiquark pairs crystallise and fill space, actually lowering the energy of the vacuum in the process.
Quarks come with a charge (akin to electric charge) known as colour charge. The colour charge of an individual quark creates a disturbance in the Grid that grows with distance from that quark. Nature cancels out the disturbance by requiring an antiquark to be in the vicinity of the offending quark, lowering the energy of the vacuum. It also renders it impossible to ever observe a single quark in isolation – at least without melting the quark-antiquark condensate (something that seems to have been , New York, at temperatures 300 million times hotter than the surface of the sun).
Quantum uncertainty, however, will not allow the antiquark to reside precisely next to its quark partner, and that wiggle room between them leaves a bit of remnant disturbance, or energy, in the Grid. Thanks to m = E/c2, that energy endows all of matter with 95 per cent of its mass. All matter that’s wrapped up in atoms, that is, which itself is only the tiniest fraction of a universe dominated by dark matter and dark energy.
Still, the idea that all familiar mass – our desks, chairs, bodies – comes from energy crystallised out of nothing is rather mind-bending. And it leads Wilczek to wonder, is the Grid’s metric field – that is, space and time themselves – a condensate that similarly crystallised from nothingness in the earliest moments of the big bang?
“Are space and time also crystallised from nothingness?”
The Lightness of Being is an apt description of Wilczek’s writing style, which manages to be at once profound and light, filled with humour, wordplay and original explanations of difficult concepts. The book is also well timed in anticipation of the data that will soon be pouring in from CERN’s Large Hadron Collider. If Wilczek is right, this much vaunted particle accelerator may discover not only the God particle, but some of the secrets of nothing.
Quantum World – Learn more about a weird world in our comprehensive special report.
The Large Hadron Collider – find out more about the world’s biggest experiment in our cutting-edge special report.
The Lightness of Being: Mass, ether and the unification of forces
Basic Books