Mini Big Bangs? Or "God Particles"? Or What?

It's a pretty exciting time in fundamental physics!  The gigantic Large Hadron Collider (LHC), which is the world's most expensive and complex single machine, is finally smashing particles together as of last week. 

The LHC is a particle accelerator that speeds up protons to insanely high energies and collides them with each other.  The energy the protons carry is transformed into mass in these collisions, creating a spray of exotic particles.  These particles are created out of energy according to Einstein's famous E-mc^2 equation, which says that energy and mass can be exchanged.  The goal here is not to break up the protons and find out their structure, but to create new forms of matter that haven't yet been discovered. 

Mini Big Bangs?

If you read any popular science news this week, you might have run into quotes like this one:  "Physicists smashed sub-atomic particles into each other with record energy on Tuesday, creating thousands of mini-Big Bangs like the primeval explosion that gave birth to the universe 13.7 billion years ago."  This quote is from a Reuters article by Robert Evans and Jonathan Lynn, published in the New York Times under the title "Mini  Big Bangs Created in Cosmos Origins Project". 

Is this true?  Is this machine really making "mini big bangs"?  Well, no, not exactly.  The Big Bang is often mentioned in connection with LHC science, but that's not because it's capable of creating explosions that birth universes (as far as we know anyway!).   One of the reasons high energy collisions are so interesting is because they approximate the conditions of the universe just a tiny fraction of a second after the Big Bang.  The early universe was a hot, dense sea of particles, and the laws of physics under those conditions are something we still don't fully understand.  We hope that by replicating those early-universe conditions momentarily in a collider like the LHC, we may be able to create deeper theories of the structure of matter that allow us to better understand the whole history of the universe.  So, while each proton collision at the LHC approximates conditions shortly after the Big Bang, it isn't "creating thousands of mini-Big Bangs". 


God Particles?

Some of the articles you'll see in the news describe the LHC as chasing the "God Particle".  For example, here's an article from Time Magazine entitled "Why the Collider Matters:  In Search of the God Particle".  The term "God Particle" is a nickname for a particular particle whose existence is speculated but has not yet been proven.  Its more formal name is the "Higgs Boson".  Within the current physics theory that we have to describe the properties of particles and their interactions, the Higgs Particle plays a critical role.  It is a hypothetical particle that is predicted, in some sense, by the mathematics that physicists have used to describe and model the behavior of the known particles in this fundamental theory, which is called the Standard Model.  The Higgs is the "missing piece" in the Standard Model.  It gets the name "God Particle" both because it is a critical component to the theory and because physicists have spent decades trying to discover its existence, so far to no avail. 

If the Higgs particle exists, it is a very heavy particle (much heavier than a proton).  Since energy and mass can be exchanged, you can potentially create very heavy particles in the laboratory in the context of very high energy collisions of other particles.  This is why the LHC has a good chance of finally creating Higgs particles in a controlled environment in which they can be studied.  If they are seen, it will be one of the major discoveries that physicists have spent the last couple of decades pursuing.