Above: Image © istockphoto.com/lineartestpilot
Imagine you were a master chef who was served a delicious mystery dish. Wouldn’t you try to figure out the recipe—which ingredients were used and how they combined to produce something so yummy? And wouldn’t you put your guesses to the test in the kitchen? I bet you would!
Fast fact: The discovery of the Higgs boson was the result of the biggest and most expensive experiment ever run. It involved the collaboration of a large number of mathematicians, physicists, and engineers from many countries.Physicists are a bit like chefs, except they’re trying to figure out the recipe for the universe. This recipe would be a mathematical equation, and instead of testing it in a kitchen, researchers use humongous underground tunnels such as the Large Hadron Collider (LHC). These intensely magnetized and exceptionally cold tunnels try to the mimic conditions in which the universe was born, when highly energized particles moving at tremendous speeds collided with each other.
It was inside the LHC that scientists recently found the Higgs boson, hiding in the matter left over after a collision of protons. For half a century, physicists had been predicting its existence, and actually finding it filled a major gap in their understanding of the universe. The physicists who first described the particle—Peter Higgs and Francois Englert
won the 2013 Nobel Prize in Physics.
So what makes the Higgs such an important ingredient in the universe? Like a chef trying to recreate a delicious meal but unable to find a key ingredient, physicists have spend decades trying to understand a property that is essential to our universe: mass.
The Particle Adventure
Take an interactive tour of elementary particles and the equipment used to study them! Offered by the Berkeley Lab:
You could say that mass is what allows our universe, our entire material world, to exist. While you might take it for granted, until recently no one was really sure how to account for mass or to explain why different particles have different masses. This means that no one could really explain the enormous diversity of the universe either!
But now that they know the Higgs boson is real, physicists can finally explain why mass exists. In other words, the Higgs has unlocked one of the greatest mysteries of all time by showing why our world is the way it is.
How does the Higgs boson explain mass? Until recently, physicists’ recipe for the universe, called the Standard Model, already included all sorts of elementary particles, such as quarks, leptons, and bosons. Quarks make up the protons and neutrons found inside an atom’s nucleus. The most famous example of a lepton would be the negatively charged electrons located outside the nucleus. And bosons account for various energy fields, such as electricity and light. However, none of these particles explain mass.
Finally, with the addition of the Higgs boson to the list, mass can be explained. It turns out that all elementary particles are surrounded by a continuum of Higgs bosons. In other words, these newly-discovered bosons fill up the space between particles, forming the Higgs field. Particles like the photons encounter no resistance when they move through the field, which is why they move very fast and have no mass. Other particles, such as the electrons, encounter slight resistance and therefore have some mass. As a result, they move more slowly than photons. Top quarks have the hardest time passing through the Higgs field, which explains their (relatively) huge mass.
Fast fact: Passing through the Higgs field would be like passing through water, where some things, like fish, can move freely while others can barely move.To summarize, each elementary particle owes its specific mass, or lack thereof, to the Higgs boson. At the beginning of the universe, before the Higgs field formed, particles did not have mass and moved at the speed of light. Then the Higgs bosons emerged, slowing down particles and giving them mass. Eventually, these particles slowed down enough to form atoms, which make up the material world as we know it today!
No wonder the Higgs is often referred to as “the God particle”! Without it there would be no mass, which means that the world as we know it would cease to exist.
Collision Course (Jeffrey Delviscio, Catherine Spangler and Soo-Jeong Kang, The New York Times) Higgs Boson Predictors Awarded the 2013 Nobel Physics Prize (Clara Moskowitz, Scientific American) Higgs boson-like particle discovery claimed at LHC (Paul Rincon, BBC) The Higgs Boson Walks into a Church… (Brian Malow, Scientific American) Timeline: The Higgs, From Theory to Reality (New York Times) What exactly is the Higgs boson? (Jonathan Atteberry, How Stuff Works) What is a Higgs boson? (Don Lincoln, YouTube) What Is the Higgs? (Nigel Holmes, New York Times) What’s the Matter with Mass? (Marisa Azad, CurioCity) Why the Higgs Boson Matters (Steven Weinberg, New York Times)