Quark-gluon plasma - other than sounding cool as hell - is what scientists believe the entire universe was like immediately after the Big Bang. It's made up of quarks, which are the elementary building blocks of positive charged protons and neutral neutrons and gluons, particles that glue quarks together using the strong force. A physicist says that "if you had a cubic centimetre of this stuff, it would weigh 40 billion tons."
To make that magic matter, the LHC was used to smash together lead ions at nearly the speed of light. Scientists did it in hopes of gaining a better feel and understanding for what happened to quark-gluon plasma as the universe cooled. And to play God, of course. [National Geographic]
Image credit: Mona Schweizer/CERN