Margaret Thatcher walking into a room full of supporters. A Siberian snow field. A Christmas gift box that seems empty but isn't. A barracuda fish swimming through water faster than a heavy man.
These are some of the analogies that scientists have used over the years as they tried to put in plain words the workings of the elusive Higgs boson particles.
Simply put, the Higgs mechanism is what slows down the world's smallest building blocks and gives them their mass, making the universe what it is now.
In a milestone announcement Wednesday, researchers at CERN, the European Organization for Nuclear Research, said they had found a new particle which behaves as it could be the long-sought Higgs boson.
Tara Shears, a particle physicist at the University of Liverpool, said it was a landmark moment "up there with the moon landings." Others predicted the discovery will help buttress the way scientists understand how the universe works.
But how best to describe the concept, named after the British physicist Peter Higgs, one of the scientists who developed the theory in the 1960s?
Enters the Margaret Thatcher explanation.
David Miller, a physicist at University College, London, won a bottle of Veuve Clicquot champagne from Tory British science minister William Waldegrave, who had challenged scientists in 1993 to come up with the best explanation for the Higgs.
In Prof. Miller's cheeky submission, imagine a cocktail party of Conservative party workers. When Ms. Thatcher walks in, people begin to cluster around her. As the ex-prime minister moves, the juggernaut around her makes it difficult for her to stop. And if she stops, the knot of people surrounding her will make it harder for her to get moving again.
This is the Higgs mechanism.
Over the years, Prof. Miller's explanation has been updated with other celebrities. On Wednesday, Queen's University physics professor Philippe Di Stefano, for example, spoke of Justin Bieber entering a room full of fans.
Non-Bieber unknowns that don't interact with anyone would walk through the room unimpeded, like photons that go at the speed of light and have no mass, Prof. Di Stefano said.
Don Lincoln, a senior scientist at the U.S. Department of Energy's Fermi National Accelerator Laboratory, compares the Higgs field to a pool of water.
In a video produced by the Fermilab, Dr. Lincoln describes how a barracuda, with its streamlined body, would slice through the water, like a whale, whereas a hefty man would move more slowly, being more massive.
The water molecules that create drag are the Higgs boson particles.
The Higgs theory is crucial because it helps clarify why some subatomic particles have great mass and others none, Dr. Lincoln said.
British physicist John Hill compares the Higgs field to an endless Siberian snow field. Some particles, like skiers, can move fast with minimal interaction, while others, walking on foot, would sink deeply.
The Higgs theory, he said, is crucial because it helps reconcile the lack of symmetry between particles as scientists have tried to explain their behaviour through the Standard Model that has governed particle physics in the last four decades.
In an article he wrote last year in the British tabloid The Sun, Brian Cox, a professor at the University of Manchester's School of Physics and Astronomy, asked readers to imagine that the universe's empty spaces are permeated by an invisible field of particles that stick to other elementary particles and gives them mass.
"Have a look at one of your Christmas presents. Inside the box, Higgs said, there are Higgs particles. Countless billions of them. The energy they store is greater than that given out by the sun in a thousand years," Prof. Cox wrote.
"And you don't really notice. Except you do, indirectly, because their job is to give mass to the smallest bits of matter in the universe — the subatomic building blocks out of which you are made."
HOW TO EXPLAIN THE HIGGS BOSON TO YOUR FRIENDS
The heart of the matter
The elusive Higgs boson is thought to be the reason why matter has mass – and it took a $10-billion research supercollider to find evidence that it might exist. But now that scientists believe they've found it, they're one step closer to understanding why stars, planets and life exist at all
What is the Higgs boson?
Named after Peter Higgs, a University of Edinburgh physicist, the Higgs boson is crucial to understanding the origin of mass. Shortly after the Big Bang, it is thought that many particles had no mass, but became heavy later on thanks to the Higgs field. Any particles that interact with this field are given mass. The Higgs boson is the signature particle of the field.
What Prof. Higgs had to say:
"For me personally it is just the confirmation of something I did 48 years ago, and it is very satisfying to be proved right in some way. … I haven't been dreaming about it for 48 years because I had other things to do with my life. At the beginning, I had no expectation that I would still be alive when it happened."
"This is just the beginning," says James Gillies, a spokesman for CERN. Scientists will keep probing the new particle until they fully understand how it works. In doing so they hope to understand the 96 per cent of the universe that remains hidden from view. This may result in the discovery of new particles and even hitherto unknown forces of nature.
How to explain it to people you're trying to impress:
"The Higgs boson is an elementary scalar particle first posited in 1962, as a potential byproduct of the mechanism by which a hypothetical, ubiquitous quantum field – the so-called Higgs field – gives mass to elementary particles. More specifically, in the standard model of particle physics, the existence of the Higgs boson explains how spontaneous breaking of electroweak symmetry takes place in nature."
How to explain it to, say, English undergraduates:
The Higgs boson (pronounced like "boatswain") is a type of subatomic punctuation with a weight somewhere between a tiny semicolon and an invisible comma. Without it the universe would be a meaningless cloud of gibberish – a bit like The Da Vinci Code, if you read that."
- From wire services