LHC – “BIG BANG MACHINE” – The Crown Jewel Of CERN

The Large Hadron Collider is the most beautiful and the most sophisticated machine mankind has ever built. Despite the underlying principle being simple, the LHC has been a very complicated machine to perform experiments on. But all the painstaking process has not gone in vain, and it has proven to be the saviour by confirming the predictions of many theories, hence being a milestone in modern physics.

History of elementary particle physics

At the end of the 19th century, physicists believed that physics was completed and there was no new theory needed and things were finally declining. But poor them, they had no idea what nature had in store for them. In a short span of just 50-60 years, things had drastically changed. Now they were sitting there staring at the mess in front of them. There ware so many particles discovered that it was all bizarre and unexplainable. They were all such unexpected discoveries that upon the discovery of the muon, Nobel laureate Isidor Isaac Rabi famously quipped, “Who ordered that?”. Physics was like chemistry before Mendeleev gave his periodic table, in complete chaos, helpless about the zoo of particles mocking at them. 

Willis Lamb began his Nobel Prize acceptance speech in 1955 with the words,
“When the Nobel Prizes were first awarded in 1901, physicists knew something of just two objects which are now called ‘elementary particles’: the electron and the proton. A deluge of other ‘elementary’ particles appeared after 1930; neutron, neutrino, µmeson, πmeson, heavier mesons, and various hyperons. I have heard it said that “the finder of a new elementary particle used to be rewarded by a Nobel Prize, but such a discovery now ought to be punished by a $10,000 fine”.
[Source: Les Prix Nobel 1955, The Nobel Foundation, Stockholm.]

This was all sorted by Murray Gell-Mann who gave the most elegant way of quantifying these elementary particles. It is based on the SU(3) model of group theory and is called the eightfold way. He managed to triumphantly explain the classification of all these particles. But he did not stop there, he also predicted the existence of new particles based on his theory.

Detection of the elementary particles

The discovery of most of these elementary particles was all thanks to cosmic rays. 
‘Cosmic rays’ is the godly name given to the stream of particles from outer space entering the Earth’s atmosphere. It comprises of mainly high energy protons, electrons and other atomic nuclei,  darting at near-light speeds. These high energy particles rain down on Earth, smash head-on with atoms in the upper atmosphere and tear them apart. Thus they form a shower of ‘secondary particles’ which then reach down to the Earth. These particles can be detected in laboratories by using bubble chambers where the paths followed by the particles is registered. This path can be then analyzed and used to determine the nature of the particles. But most heavy particles are unstable and hence decay into lighter particles before reaching down. And this means only light particles can be detected in laboratories. Thus cosmic rays can never be a possibility to confirm the existence of these heavy particles. This means that the confirmation of predictions of elementary particle physics could not be done using them. Physicist needed a new method to recreate this natural phenomenon in laboratories.

What does Large Hadron Collider do?

Particle accelerators are old science and have already been set up in lots of places. The Large Hadron Collider, set up by CERN  is the most advanced and the costliest particle accelerator built till date and it lives up to the expectations.

Charged particles are deflected by electric and magnetic fields. The particle accelerators take advantage of this phenomenon to accelerate the particles, guiding them through the huge, circular tunnels. Superconducting magnets at temperatures close to absolute zero (-273.15 ℃), cooled using liquid helium, are used to guide these particles. They form beams travelling at phenomenal speeds, which upon completion of few rotations gain a colossal amount of energy and momentum. These guided beams then collide head-on expending all the gained energy into creating new particles. CERN has, till date, collected petabytes of data, running the experiment numerous times and generating datasets of the statistical data obtained.  

LHC has been called ‘The Big Bang Machine’ in contemporary literature. This is because it was used to recreate the conditions of the universe shortly after the Big Bang. On the 7th of November 2010, LHC collided two beams of lead ions instead of protons to recreate a mini Big Bang. The temperatures being reached up to a million times hotter than at the centre of the Sun. 
Another great and publicly celebrated discovery is that of the ‘God particle’, the Higgs Boson. It is the particle corresponding to the Higgs field, which gives mass to all other particles. On July 4 2012, scientists at CERN declared an end to the long-lasting search for the God particle, which was observed in a high energy proton-proton collision.
Further experiments are being performed in LHC hoping to find out more about the dark matter which physicist conjecture, is made up of particle we haven’t theorized or detected yet. 

In contemporary literature

Large Hadron Collider has been, in contemporary literature, called ‘The Doomsday collider’. This is because there have been many conspiracy theories about LHC ending up destroying the world. It may be about creating a black hole, or about Higgs Boson causing a quantum fluctuation called vacuum bubble that sends the universe into instability and finally destruction, or about strange matter being created that ends up converting ordinary matter into strange too, and whatsoever. But scientists have been dismissing all these possibilities from ever since. CERN has hosted a page on its website regarding the safety of its collider, you can view the page here.

Right now the LHC has entered a Long Shutdown 2 (LS2). The first shutdown LS1 in 2013 was to increase the energy of collider from 7 TeV to 13TeV. This time it is for a few major upgrades in the upper limit of the energy of the collider. In this time scientists probe loads of data gathered during the running period, keeping the search and curiosity of physics alive. The LHC has lived up to its fame of being the most complicated device ever built by playing a pivotal role in making discoveries which otherwise would never be possible.