Large Hadron Collider

The large Hadron Collider, or LHC, was a device built by CERN in 2008 (TV: Extremis) to find the Higgs particle. (AUDIO: Lost Souls) It was first used on 10 September 2008, and was housed at least until 2017 in CERN's accelerator complex, (TV: Extremis) beneath France and Switzerland. (AUDIO: Lost Souls) It was the world's largest and most powerful particle accelerator, (TV: Extremis) with a circumference of twenty-seven kilometres (AUDIO: Lost Souls, TV: Extremis) of superconducting magnets, and with a number of accelerating structures to boost the energy of the particles along the way. (TV: Extremis)

As described on a plaque at CERN, "inside the accelerator, two high-energy particle beams travel at close to the speed of light before they start to collide. The beams travel in opposite directions in separate beam pipes — two tubes kept at ultrahigh vacuum. They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets. The electromagnets are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy." Because this required the magnets to be cooled at -271.3°C — a temperature colder than outer space — much of the accelerator was connected to a distribution system of liquid helium, to cool the magnets, as well as to other supply services. (TV: Extremis)

Due to its incredible power, before the LHC's first testing, many were worried it might open a gateway to a parallel dimension, create a black hole, or even turn the world inside out. In fact, after a test lasting a few nanoseconds, (AUDIO: Lost Souls) in 2008, (TV: Extremis) the Large Hadron Collider inadvertently opened a portal to another reality, and let out some neutron eaters, which proceeded to eat humans at CERN. When the collider started up properly, Professor Johnson and Jack Harkness had protons and antiprotons fired upon one another to cancel each other out. This closed the portal to the neutron eaters' dimension, and the Higgs particle was created as a side-effect. (AUDIO: Lost Souls)

"The large Hadron Collider. A thing of beauty. Oh, I love what they're doing, pushing the boundaries of human knowledge. [...] They're looking for the Higgs particle. The fundamental particle of existence. Look out the window. See those clouds? [...] They look solid, though, yeah? But they're not. [...] Well, imagine you had a huge digital camera, and you could zoom in, right into the clouds so you could see the individual raindrops, then zoom in further and you ... you see that the raindrops are made of molecules, H2O. Then zoom in further and see what hydrogen is made of, one proton and one electron, and zoom in to the proton — that's where it gets interesting. At CERN, they've found a way to look at those particles. To the very building blocks of matter of the universe, of everything.

They've built the world's biggest particle collider. It goes through Switzerland and France, deep underground. It's in a circular tunnel, twenty-seven kilometres round. They're gonna send protons racing around it at the speed of light, smash them into each other, and boom!"

- Jack Harkness