The Large Hadron Collider (LHC), near Geneva
Hadron Collider Day
Other Scottish Country Dances for this Day
Today's Musings, History & Folklore
"The LHC accelerates
The protons and the lead
And the things that it discovers
Will rock you in the head"
~ Large Hadron Rap, Alpinekat
The Large Hadron Collider (LHC) is a 27km long ring-shaped tunnel made mainly of superconducting magnets which sits 100m underground near Geneva, Switzerland, and acts as a particle accelerator. Two beams of particles called hadrons - protons or lead ions are sent hurtling around the ring in opposite directions. They'll travel close to the speed of light at very high energies, and are encouraged to collide! These collisions produce massive particles, such as the Higgs boson or the top quark. By measuring their properties, scientists increase our understanding of matter and of the origins of the Universe. These massive particles almost immediately transform (or decay) into lighter particles, which in turn also decay. The particles emerging from the successive links in this decay chain are identified in the layers of the detector. Up, Down, Strange, Charm, Bottom ,Top! DO THE QUARK, everybody! Woo hoo! ⚛️
The Large Hadron Collider
September 10th marks the day the Large Hadron Collider, the world's largest and most powerful particle collider, went live in 2008.
From the dance notes:
The four couples can be taken to represent the four experiments round the LHC ring. The figures (very) vaguely reflect the operation of the LHC with injection of "probe" beams (1st couple solo), full circulating "physics" beams round the two rings (interlocking reels), acceleration (right or left hands across and chase) and stable collisions (Schiehallion reel) - though of course the dancers should not actually collide! The quick turns at the end of bars 12 and 20 are quite contrary to the way the proton beams behave but allow the dancers to change direction from time to time. The Schiehallion reel is only 3/4 to suggest that quite often the LHC fills are interrupted earlier than expected due to overenthusiastic safety systems cutting in.
Built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and engineers from over 100 countries, as well as hundreds of universities and laboratories, the Large Hadron Collider lies in a tunnel 27 kilometres (17 mi) in circumference, as deep as 175 metres (574 ft) beneath the France–Switzerland border near Geneva, Switzerland.
The LHC's aim is to allow physicists to test the predictions of different theories of particle physics and high-energy physics and in particular, to prove or disprove the existence of the large family of new theoretical particles.
The machine accelerates two beams of protons around a 27km loop at close to the speed of light. The beams go in different directions and are crossed at four points where the protons slam into one another inside giant detectors. The intense energy of the collisions is converted into all manner of particles. New particles are unstable, and the moment they are made they disintegrate into other more common particles. This creates unexpected patterns in the LHC data which reveal the particle’s presence.
For the instructive and amusing Large Hadron Rap, by science journalist Katherine McAlpine, click the picture below of collision events from the detector or find the lyrics here.