Large Hadron Collider

“Science is an integral part of culture. It’s not this foreign thing, done by an arcane priesthood.”


Stephan Jay Gould


Few days before September 10, 2008, news flashed uninterrupted on all news channels,which expressed their concerns and implications of conducting an experiment that could endanger the existence of this very planet. This news was about Large Hadron Collider abbreviated as LHC and the experiment to be conducted thereon which was termed as the all time great experiment of all times.
LHC is world’s largest and highest-energy particle accelerator built by the European Organization for Nuclear Research (CERN) intended to collide opposing beams of protons or lead ions, each moving at approximately 99.999999% of the speed of light so as to recreate conditions a fraction of a second after the big bang.


The LHC is built in a circular tunnel 27 km in circumference and 3.8 m in diameter, buried 50 to 175m below ground between the Jura Mountains and the Alps on the French-Swiss border to the North-West of Geneva. It is funded by and built in collaboration with over 10,000 scientists and engineers from over 100 countries as well as hundreds of universities and laboratories. The Indian universities contributing towards LHC are IIT Bombay, TIFR Mumbai, the Universities of Rajasthan, Punjab, Jammu and Aligarh, Variable Energy Cyclotron Centre and the Saha Institute, Kolkata and IOP at Bhubaneswar.


On September 10, 2008, the proton beams were successfully circulated in the main ring of the LHC for the first time. On September 19, 2008, the operations were halted due to a serious fault between two superconducting bending magnets. Owing to the already planned winter shutdown, the LHC will not be operational again until the spring of 2009.


The LHC was built with an aim to help scientists answer key unresolved questions in particle physics. The unprecedented energy (7 TeV= 1012 electron Volts per beam) it achieves is expected to yield some unexpected results.


Everything in this universe has been found to be made from twelve basic building blocks called fundamental particles, governed by four fundamental forces. The understanding of the relation that exists among these twelve particles and three of the forces constitute the Standard Model of particle physics, but it is not unified and cannot tell the whole story. To fill in the missing knowledge requires experimental data, and the next big step to achieving this is with LHC.


There have always been queries about the origin of mass, its very existence and many others. At present, there are no established answers to these questions. The most likely explanation may be found in Higgs boson, a key undiscovered particle that is essential for the Standard Model to work. The ATLAS and CMS experiments will be actively searching for signs of this particle.


All things in the universe are made up of ordinary particles, collectively referred to as matter, forming 4% of the Universe. Dark matter and dark energy are believed to make up the remaining proportion, but they are extremely difficult to detect and study, other than through the gravitational forces they exert. Investigating the nature of dark matter and dark energy is one of the biggest challenges today in the fields of particle physics and cosmology. The ATLAS and CMS experiments will look for supersymmetric particles to test a likely hypothesis for the make-up of dark matter.


Scientists have been trying to identify the secrets of the Big Bang- What was matter like within the first second of the Universe’s life? The ALICE experiment will recreate conditions similar to those just after the Big Bang.


Einstein showed that the three dimensions of space are related to time (also stated in ‘Brief History of Time’ by Stephen Hawking). Subsequent theories propose that further hidden dimensions of space may exist. These may become detectable at very high energies, so data from all the detectors will be carefully analyzed to look for signs of extra dimensions.


The six experiments at the LHC are operated upon by scientists from institutes all over the world. Each experiment is distinct and characterized by its unique particle detector.


ALICE: LHC will collide lead ions to recreate the conditions just after the Big Bang under laboratory conditions..




LHCb (Large Hadron Collider beauty): The LHCb experiment will help understand why we live in a Universe that appears to be composed almost entirely of matter, but no antimatter. The LHCb collaboration has 650 scientists from 48 institutes in 13 countries.


The ATLAS, CMS, ALICE and LHCb detectors are installed in four huge underground caverns located around the ring of the LHC. The detectors used by the TOTEM experiment are positioned near the CMS detector, whereas those used by LHCf are near the ATLAS detector.


The Large Hadron Collider will produce roughly 15 petabytes (15 million gigabytes) of data annually – enough to fill more than 1.7 million dual-layer DVDs a year. Thousands of scientists around the world want to access and analyse this data, so CERN has collaborated with institutions in 33 different countries to operate a distributed computing and data storage infrastructure: the LHC Computing Grid. Data from the LHC experiments is distributed around the globe. Individual scientists can access the LHC data from their home country, using local computer clusters or even individual PCs.


“The world will not come to an end when the LHC turns on. The LHC is absolutely safe. … Collisions releasing greater energy occur millions of times a day in the earth’s atmosphere and nothing terrible happens.”


Prof. Steven Hawking, Lucasian Professor of Mathematics, Cambridge University


“To think that LHC particle collisions at high energies can lead to dangerous black holes is rubbish. Such rumors were spread by unqualified people seeking sensation or publicity.”


Academician Vitaly Ginzburg, Nobel Laureate in Physics, Lebedev Institute, Moscow, and Russian Academy of Sciences


Facts and figures


The largest machine in the world: The precise circumference of the LHC accelerator is 26,659 m, with a total of 9,300 magnets inside. It is the world’s largest particle accelerator. The cryogenic distribution system of the LHC is more than 8 times the size of the world’s largest fridge.


The fastest racetrack on the planet: At full power, trillions of protons will race around the LHC accelerator ring 11,245 times a second, travelling at 99.99% the speed of light. Two beams of protons will each travel at a maximum energy of 7 TeV (tera-electronvolt), corresponding to head-to-head collisions of 14 TeV. Altogether, some 600 million collisions will take place every second.


Shruti Kapoor

[Image source:]