May 9, 2007
"Particle physics is the unbelievable in pursuit of the unimaginable. To pinpoint the smallest fragments of the universe, you have to build the biggest machine in the world..." —The Guardian
Modern theoretical particle physicists seem to be having all the fun these days. Yes, life is sweet with their days spent smashing tiny bits of matter together, devising complex theories about smashed bits of matter, and smashing even smaller bits of matter together.
But as happy as particle physicists are with their nuclear electrostatic generators, cyclotrons, and electron linear accelerators, the particle life just seems so meaningless without the yet undiscovered God particle.
Particle physicists have tackled some pretty big concepts: the special theory of relativity, quantum mechanics, the space-time continuum—you name it, they've covered it.
But not having found the God particle yet, or the "Higgs Boson" as it's also called, is starting to get the particle physicists' a little nervous. And for good reason: Without proving its existence, the concept of mass cannot be explained, and that could rock the entire foundation of physics!
It is the drive to find this mystery particle which has led to the development of the world's largest nuclear accelerator: the Large Hadron Collider (LHC). "The LHC should be...powerful enough to find the Higgs...and everything should be fine". The collider should be completed in November of 2007.
Did You Know?
Particle accelerators are used to dry the paint on soft drinks cans.
Let the Building...and the Search Begin!
The LHC is being built in collaboration with over 2,000 physicists from 34 countries. The collider, crossing the border between Switzerland and France, consists of an underground, 3 meter in diameter, concrete-lined elliptical tunnel with a circumference of 27 km. The tunnel runs at a depth ranging from 50 to 150 meters.
Running along the tunnel are two pipes enclosed within superconducting magnets cooled with liquid helium. Each pipe contains an oppositely-running proton beam. The LHC purpose is to find the Higgs Boson. But before we get into what exactly the Higgs is, let's first look at what matter is.
Did You Know?
It will take about 90 microseconds for an individual proton to travel once around the collider.
Getting to the Heart of the Matter
Everything around you (your cell phone, laptop, etc.) is composed of matter. That is to say, matter is anything that has mass and takes up space. The fundamental component of matter is the atom - a unit consisting of negatively charged electrons rotating around a central nucleus containing positively charged protons and neutral neutrons.
These particles have been shown to have an intrinsic "spin". The value of the spin is either a "half-integer" spin (making up a group of particles called "fermions"), or an "integer" spin (making up the second group of particles called "bosons").
Did You Know?
Part of the LHC will be the world's largest fridge. It could hold 150,000 sausages at a temperature colder than deep outer space. The eerie world of quantum mechanics has shown that fermions may be broken down further into "quarks" - one of the two basic constituents of matter. And, just to show that particle physicists really do have a great "taste" in humour, quarks may be divided into six different "flavours", and these subsequently into three generations.
The queen-mother of all particle theories, the Standard Model, describes the interactions between the three fundamental forces, excluding gravity.
Without getting too bogged down in quantum mechanics, Dr. Jeff Chizma, a physics professor at Thompson Rivers University summed it up this way: "the [Higgs]...is a boson, so it has [an] integer spin [of 0] making it a scalar field—this particle was invented theoretically to help solve the problem of combining the electromagnetic interaction with the weak interaction".
To really simplify things, the Higgs mechanism works similarly to how Pacman works: the massless (gauge) bosons "eat" the Higgs and become really big, thus acquiring mass.
What if there isn't a Higgs? Chizma thinks this "would be more interesting...that will tell us that we do not really understand what is going on at a fundamental level...and it will be back to the drawing board..." Only until the LHC will be completed can particle physicists stop biting their nails a little less.
Wikipedia on the Large Hadron Collider
Exploratorium on Higgs
Large Hadron Collider (LHC) Machine Outreach
Wikipedia on Quarks
CERN: What is the LHC?
Marisa Azad is majoring in molecular genetics and microbiology at Thompson Rivers University. Aside from being a self-confessed chocoholic and science junky, Marisa is a nationally-ranked athlete. Her hobbies include oil-painting, writing, and research.