A primer on the great proton smashup
From the New York Times, April 2, 2010
For those whose physics knowledge was a bit rusty, the news about the Large Hadron Collider, the world's biggest physics machine, might have been puzzling.
Yes, the collider finally crashed subatomic particles into one another last week, but why, exactly, is that important? Here is a primer on the collider - with just enough information, hopefully, to impress guests at your next cocktail party.
Let's be basic. What does a particle physicist do?
Particle physicists have one trick that they do over and over again, which is to smash things together and watch what comes tumbling out.
What does it mean to say that the collider will allow physicists to go back to the Big Bang? Is the collider a time machine?
Physicists suspect that the laws of physics evolved as the universe cooled from billions or trillions of degrees in the first moments of the Big Bang to superfrigid temperatures today (3 degrees Kelvin) - the way water changes from steam to liquid to ice as temperatures decline. As the universe cooled, physicists suspect, everything became more complicated. Particles and forces once indistinguishable developed their own identities, the way Spanish, French and Italian diverged from the original Latin.
By crashing together subatomic particles - protons - physicists create little fireballs that revisit the conditions of these earlier times and see what might have gone on back then, sort of like the scientists in Jurassic Park reincarnating dinosaurs.