CERN's enormous Large Hadron Collider, the world's largest and highest-energy particle accelerator, has successfully created a "mini-Big Bang" by smashing together lead ions instead of protons on 7 November, creating temperatures a million times hotter than the centre of the Sun. The LHC is housed in a 27km-long circular tunnel under the French-Swiss border near Geneva.
Up until now, the world's highest-energy particle accelerator has been colliding protons, in an $ multi-billion effortto uncover mysteries of the Universe's formation.The LHC is smashing together particles in a bid to unlock the secrets of formation of our Universe. Proton collisions could help spot the elusive Higgs boson particle and signs of new physical laws, such as a framework called supersymmetry.
Over for the next four weeks, scientists at the LHC will concentrate on analysing the data obtained from the lead ion collisions, with the hope to learn more about the plasma the Universe was made of a millionth of a second after the Big Bang, 13.7 billion years ago.
One of the accelerator's experiments, ALICE, has been specifically designed to smash together lead ions, but the ATLAS and Compact Muon Solenoid (CMS) experiments have also switched to the new mode.
Quarks and gluons are sub-atomic particles - some of the building blocks of matter. In the state known as quark-gluon plasma, they are freed of their attraction to one another. This plasma is believed to have existed just after the Big Bang. By studying the plasma, physicists hoped to learn more about the so-called strong force - the force that binds the nuclei of atoms together and that is responsible for 98% of their mass.
After the LHC finishes colliding lead ions, it will go back to smashing together protons once again.
Casey Kazan via BBC News