Written by Brinda Aparajita Cheema
The Large Hadron Collider has generated a lot of excitement in the scientific community. Consisting mainly of a 27-kilometer ring of superconducting magnets with several accelerating structures designed to boost the energy of the particles, the LHC is the largest and most powerful particle accelerator in the world and the latest addition to the CERN accelerator complex. It is located one hundred meters underground, beneath the border between France and Switzerland.
Discoveries made by scientists could lead to practical applications along the road, but this is not the reason why hundreds of scientists and engineers built the LHC. The main reason for the building of the LHC is to expand and deepen our knowledge of the universe.
How does it work?
The principle behind the LHC is quite simple. First, the two-particle beams are fired along two pathways, one going clockwise and another counterclockwise. Both beams are accelerated close to the speed of light. Inside the accelerator, the two beams travel in two pipes held in an ultra-high vacuum. Using superconductive electromagnets, a strong magnetic field is created that guides them around the ring of the accelerator. The electromagnets are constructed from special electrical cable coils, which operate in a superconducting state and conduct electricity efficiently without resistance or loss of energy. The magnets are required to cool down to about -271 ° C to achieve a superconducting state. Consequently, a large part of the accelerator is connected to the liquid helium distribution system that cools the magnets.
Thousands of magnets of different sizes and varieties are used to direct the beams around the accelerator. Just before the collision, another type of magnet is used to "squeeze" the particles closer together to increase the chance of collision. Detectors placed along the circumference of the collider gather data from the experiments.
What is the Large Hadron Collider searching for and its significance?
To understand how the universe works and its structure, scientists have proposed a theory called the Standard Model. This theory dwells upon the fundamental particles which constitute the universe. It combines elements of Einstein's relativity theory and quantum theory. Also, it deals with three of the four fundamental forces in the universe, the electromagnetic force, strong nuclear force, and weak nuclear force; It does not address the fourth fundamental force i.e. gravity.
The Higgs boson, previously a theoretical particle, was discovered in 2012 due to the experiments conducted using the LHC. The reason Higgs' theory is considered to be so important is that it is the last piece of the jigsaw that has enabled physicists to explain the mass of particles. Higgs introduced a field, now called the Higgs field, which endowed particles with mass through what became known as the Higgs mechanism. The position of the particle in the Higgs field will determine its mass. Thus, the discovery of the Higgs boson infers the existence of the Higgs field, which moreover implies that it is indeed the Higgs mechanism that provides particles with mass.
One of the other main focuses of LHC is dark matter. In the early moments of the universe, it is believed, matter and energy were coupled together. The particles of matter and antimatter were annihilated immediately after the separation of matter and energy. The two forms of matter would have canceled one another if there were an equal amount of matter and antimatter. However, fortunately for us, in the universe, there was a little more matter than antimatter. The current understanding of the universe suggests that matter we can observe accounts for only about 4 percent of all the matter that must exist. The movement of celestial bodies suggests that there is more matter in the universe than we can detect. Scientists have named this undetectable material dark matter. They hope to observe antimatter during LHC events. That could help us understand why there was a tiny difference in the amount of matter versus antimatter when the universe began.
Some scientists believe that the LHC is capable of uncovering evidence of other dimensions. We are used to living in a four-dimensional world — three spatial dimensions and time. However, some physicists argue that there may be other dimensions that we cannot see. Some theories only make sense when there are a few more dimensions in the universe. For instance, the existence of not less than 11 dimensions is needed for the version of string theory.
String theorists hope that the LHC will provide evidence to support their proposed model for the universe. String Theory says that the fundamental building block of the universe is not a particle, but a string. Strings can be either open-ended or closed. They can also vibrate, similar to the way the strings on the guitar vibrate when they are plucked. Different vibrations make the strings look different. A string that vibrates one way would appear as an electron whereas a string vibrating in another way would be a neutrino.
Downside and dangers of the Large Hadron Collider
It takes a lot of energy to get the LHC running. CERN estimates that the annual power consumption of the collider will be approximately 750-gigawatt hours. That is almost $30 million a year in electricity bills for a facility that cost more than $6 billion to build.
One fear is that the LHC could make black holes. Black holes are regions where matter collapses to the point of infinite density. CERN scientists agree that there is a probability of the LHC creating black holes, but also predict the black holes would be on a subatomic scale and would immediately collapse without causing any damage.
In the future, the LHC will be crucial in giving us answers to long-asked questions about the particles that constitute the building blocks of the universe; a stepping stone to understanding the mystery surrounding the beginning of the universe. The constant upgrades made to the LHC foretells a promising future in the scientific field of particle physics.